Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.
White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.
Morphologic alteration of small B LYMPHOCYTES or T LYMPHOCYTES in culture into large blast-like cells able to synthesize DNA and RNA and to divide mitotically. It is induced by INTERLEUKINS; MITOGENS such as PHYTOHEMAGGLUTININS, and by specific ANTIGENS. It may also occur in vivo as in GRAFT REJECTION.
Complex of at least five membrane-bound polypeptides in mature T-lymphocytes that are non-covalently associated with one another and with the T-cell receptor (RECEPTORS, ANTIGEN, T-CELL). The CD3 complex includes the gamma, delta, epsilon, zeta, and eta chains (subunits). When antigen binds to the T-cell receptor, the CD3 complex transduces the activating signals to the cytoplasm of the T-cell. The CD3 gamma and delta chains (subunits) are separate from and not related to the gamma/delta chains of the T-cell receptor (RECEPTORS, ANTIGEN, T-CELL, GAMMA-DELTA).
A critical subpopulation of T-lymphocytes involved in the induction of most immunological functions. The HIV virus has selective tropism for the T4 cell which expresses the CD4 phenotypic marker, a receptor for HIV. In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T-lymphocytes.
Differentiation antigens found on thymocytes and on cytotoxic and suppressor T-lymphocytes. CD8 antigens are members of the immunoglobulin supergene family and are associative recognition elements in MHC (Major Histocompatibility Complex) Class I-restricted interactions.
A critical subpopulation of regulatory T-lymphocytes involved in MHC Class I-restricted interactions. They include both cytotoxic T-lymphocytes (T-LYMPHOCYTES, CYTOTOXIC) and CD8+ suppressor T-lymphocytes.
Immunized T-lymphocytes which can directly destroy appropriate target cells. These cytotoxic lymphocytes may be generated in vitro in mixed lymphocyte cultures (MLC), in vivo during a graft-versus-host (GVH) reaction, or after immunization with an allograft, tumor cell or virally transformed or chemically modified target cell. The lytic phenomenon is sometimes referred to as cell-mediated lympholysis (CML). These CD8-positive cells are distinct from NATURAL KILLER CELLS and NATURAL KILLER T-CELLS. There are two effector phenotypes: TC1 and TC2.
Ratio of T-LYMPHOCYTES that express the CD4 ANTIGEN to those that express the CD8 ANTIGEN. This value is commonly assessed in the diagnosis and staging of diseases affecting the IMMUNE SYSTEM including HIV INFECTIONS.
Differentiation antigens residing on mammalian leukocytes. CD stands for cluster of differentiation, which refers to groups of monoclonal antibodies that show similar reactivity with certain subpopulations of antigens of a particular lineage or differentiation stage. The subpopulations of antigens are also known by the same CD designation.
The number of LYMPHOCYTES per unit volume of BLOOD.
Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation.
Costimulatory T-LYMPHOCYTE receptors that have specificity for CD80 ANTIGEN and CD86 ANTIGEN. Activation of this receptor results in increased T-cell proliferation, cytokine production and promotion of T-cell survival.
A membrane glycoprotein and differentiation antigen expressed on the surface of T-cells that binds to CD40 ANTIGENS on B-LYMPHOCYTES and induces their proliferation. Mutation of the gene for CD40 ligand is a cause of HYPER-IGM IMMUNODEFICIENCY SYNDROME, TYPE 1.
Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.
A classification of lymphocytes based on structurally or functionally different populations of cells.
A member of the tumor necrosis factor receptor superfamily with specificity for CD40 LIGAND. It is found on mature B-LYMPHOCYTES and some EPITHELIAL CELLS, lymphoid DENDRITIC CELLS. Evidence suggests that CD40-dependent activation of B-cells is important for generation of memory B-cells within the germinal centers. Mutations of the gene for CD40 antigen result in HYPER-IGM IMMUNODEFICIENCY SYNDROME, TYPE 3. Signaling of the receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.
A classification of T-lymphocytes, especially into helper/inducer, suppressor/effector, and cytotoxic subsets, based on structurally or functionally different populations of cells.
The phenomenon of target cell destruction by immunologically active effector cells. It may be brought about directly by sensitized T-lymphocytes or by lymphoid or myeloid "killer" cells, or it may be mediated by cytotoxic antibody, cytotoxic factor released by lymphoid cells, or complement.
Acidic sulfated integral membrane glycoproteins expressed in several alternatively spliced and variable glycosylated forms on a wide variety of cell types including mature T-cells, B-cells, medullary thymocytes, granulocytes, macrophages, erythrocytes, and fibroblasts. CD44 antigens are the principle cell surface receptors for hyaluronate and this interaction mediates binding of lymphocytes to high endothelial venules. (From Abbas et al., Cellular and Molecular Immunology, 2d ed, p156)
A soluble substance elaborated by antigen- or mitogen-stimulated T-LYMPHOCYTES which induces DNA synthesis in naive lymphocytes.
Antigens expressed on the cell membrane of T-lymphocytes during differentiation, activation, and normal and neoplastic transformation. Their phenotypic characterization is important in differential diagnosis and studies of thymic ontogeny and T-cell function.
An encapsulated lymphatic organ through which venous blood filters.
Glycoproteins found on immature hematopoietic cells and endothelial cells. They are the only molecules to date whose expression within the blood system is restricted to a small number of progenitor cells in the bone marrow.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Molecules on the surface of T-lymphocytes that recognize and combine with antigens. The receptors are non-covalently associated with a complex of several polypeptides collectively called CD3 antigens (ANTIGENS, CD3). Recognition of foreign antigen and the major histocompatibility complex is accomplished by a single heterodimeric antigen-receptor structure, composed of either alpha-beta (RECEPTORS, ANTIGEN, T-CELL, ALPHA-BETA) or gamma-delta (RECEPTORS, ANTIGEN, T-CELL, GAMMA-DELTA) chains.
Lymphocytes that show specificity for autologous tumor cells. Ex vivo isolation and culturing of TIL with interleukin-2, followed by reinfusion into the patient, is one form of adoptive immunotherapy of cancer.
Process of classifying cells of the immune system based on structural and functional differences. The process is commonly used to analyze and sort T-lymphocytes into subsets based on CD antigens by the technique of flow cytometry.
Glycoprotein members of the immunoglobulin superfamily which participate in T-cell adhesion and activation. They are expressed on most peripheral T-lymphocytes, natural killer cells, and thymocytes, and function as co-receptors or accessory molecules in the T-cell receptor complex.
Antibodies produced by a single clone of cells.
A single, unpaired primary lymphoid organ situated in the MEDIASTINUM, extending superiorly into the neck to the lower edge of the THYROID GLAND and inferiorly to the fourth costal cartilage. It is necessary for normal development of immunologic function early in life. By puberty, it begins to involute and much of the tissue is replaced by fat.
The major interferon produced by mitogenically or antigenically stimulated LYMPHOCYTES. It is structurally different from TYPE I INTERFERON and its major activity is immunoregulation. It has been implicated in the expression of CLASS II HISTOCOMPATIBILITY ANTIGENS in cells that do not normally produce them, leading to AUTOIMMUNE DISEASES.
A tumor necrosis factor receptor subtype found in a variety of tissues and on activated LYMPHOCYTES. It has specificity for FAS LIGAND and plays a role in regulation of peripheral immune responses and APOPTOSIS. Multiple isoforms of the protein exist due to multiple ALTERNATIVE SPLICING. The activated receptor signals via a conserved death domain that associates with specific TNF RECEPTOR-ASSOCIATED FACTORS in the CYTOPLASM.
A costimulatory ligand expressed by ANTIGEN-PRESENTING CELLS that binds to CTLA-4 ANTIGEN with high specificity and to CD28 ANTIGEN with low specificity. The interaction of CD80 with CD28 ANTIGEN provides a costimulatory signal to T-LYMPHOCYTES, while its interaction with CTLA-4 ANTIGEN may play a role in inducing PERIPHERAL TOLERANCE.
A bifunctional enzyme that catalyzes the synthesis and HYDROLYSIS of CYCLIC ADP-RIBOSE (cADPR) from NAD+ to ADP-RIBOSE. It is a cell surface molecule which is predominantly expressed on LYMPHOID CELLS and MYELOID CELLS.
A group of genetically identical cells all descended from a single common ancestral cell by mitosis in eukaryotes or by binary fission in prokaryotes. Clone cells also include populations of recombinant DNA molecules all carrying the same inserted sequence. (From King & Stansfield, Dictionary of Genetics, 4th ed)
Antigens on surfaces of cells, including infectious or foreign cells or viruses. They are usually protein-containing groups on cell membranes or walls and may be isolated.
Glycolipid-anchored membrane glycoproteins expressed on cells of the myelomonocyte lineage including monocytes, macrophages, and some granulocytes. They function as receptors for the complex of lipopolysaccharide (LPS) and LPS-binding protein.
Subpopulation of CD4+ lymphocytes that cooperate with other lymphocytes (either T or B) to initiate a variety of immune functions. For example, helper-inducer T-cells cooperate with B-cells to produce antibodies to thymus-dependent antigens and with other subpopulations of T-cells to initiate a variety of cell-mediated immune functions.
Glycoproteins expressed on cortical thymocytes and on some dendritic cells and B-cells. Their structure is similar to that of MHC Class I and their function has been postulated as similar also. CD1 antigens are highly specific markers for human LANGERHANS CELLS.
Differentiation antigens expressed on B-lymphocytes and B-cell precursors. They are involved in regulation of B-cell proliferation.
Mucoproteins isolated from the kidney bean (Phaseolus vulgaris); some of them are mitogenic to lymphocytes, others agglutinate all or certain types of erythrocytes or lymphocytes. They are used mainly in the study of immune mechanisms and in cell culture.
T-cell receptors composed of CD3-associated alpha and beta polypeptide chains and expressed primarily in CD4+ or CD8+ T-cells. Unlike immunoglobulins, the alpha-beta T-cell receptors recognize antigens only when presented in association with major histocompatibility (MHC) molecules.
Measure of histocompatibility at the HL-A locus. Peripheral blood lymphocytes from two individuals are mixed together in tissue culture for several days. Lymphocytes from incompatible individuals will stimulate each other to proliferate significantly (measured by tritiated thymidine uptake) whereas those from compatible individuals will not. In the one-way MLC test, the lymphocytes from one of the individuals are inactivated (usually by treatment with MITOMYCIN or radiation) thereby allowing only the untreated remaining population of cells to proliferate in response to foreign histocompatibility antigens.
Non-antibody proteins secreted by inflammatory leukocytes and some non-leukocytic cells, that act as intercellular mediators. They differ from classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. They generally act locally in a paracrine or autocrine rather than endocrine manner.
Glycoproteins expressed on all mature T-cells, thymocytes, and a subset of mature B-cells. Antibodies specific for CD5 can enhance T-cell receptor-mediated T-cell activation. The B-cell-specific molecule CD72 is a natural ligand for CD5. (From Abbas et al., Cellular and Molecular Immunology, 2d ed, p156)
They are oval or bean shaped bodies (1 - 30 mm in diameter) located along the lymphatic system.
CD4-positive T cells that inhibit immunopathology or autoimmune disease in vivo. They inhibit the immune response by influencing the activity of other cell types. Regulatory T-cells include naturally occurring CD4+CD25+ cells, IL-10 secreting Tr1 cells, and Th3 cells.
The number of CD4-POSITIVE T-LYMPHOCYTES per unit volume of BLOOD. Determination requires the use of a fluorescence-activated flow cytometer.
Established cell cultures that have the potential to propagate indefinitely.
A costimulatory ligand expressed by ANTIGEN-PRESENTING CELLS that binds to CD28 ANTIGEN with high specificity and to CTLA-4 ANTIGEN with low specificity. The interaction of CD86 with CD28 ANTIGEN provides a stimulatory signal to T-LYMPHOCYTES, while its interaction with CTLA-4 ANTIGEN may play a role in inducing PERIPHERAL TOLERANCE.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Specialized cells of the hematopoietic system that have branch-like extensions. They are found throughout the lymphatic system, and in non-lymphoid tissues such as SKIN and the epithelia of the intestinal, respiratory, and reproductive tracts. They trap and process ANTIGENS, and present them to T-CELLS, thereby stimulating CELL-MEDIATED IMMUNITY. They are different from the non-hematopoietic FOLLICULAR DENDRITIC CELLS, which have a similar morphology and immune system function, but with respect to humoral immunity (ANTIBODY PRODUCTION).
Antigens expressed primarily on the membranes of living cells during sequential stages of maturation and differentiation. As immunologic markers they have high organ and tissue specificity and are useful as probes in studies of normal cell development as well as neoplastic transformation.
The 140 kDa isoform of NCAM (neural cell adhesion molecule) containing a transmembrane domain and short cytoplasmic tail. It is expressed by all lymphocytes mediating non-MHC restricted cytotoxicity and is present on some neural tissues and tumors.
Receptors present on activated T-LYMPHOCYTES and B-LYMPHOCYTES that are specific for INTERLEUKIN-2 and play an important role in LYMPHOCYTE ACTIVATION. They are heterotrimeric proteins consisting of the INTERLEUKIN-2 RECEPTOR ALPHA SUBUNIT, the INTERLEUKIN-2 RECEPTOR BETA SUBUNIT, and the INTERLEUKIN RECEPTOR COMMON GAMMA-CHAIN.
High-molecular weight glycoproteins uniquely expressed on the surface of LEUKOCYTES and their hemopoietic progenitors. They contain a cytoplasmic protein tyrosine phosphatase activity which plays a role in intracellular signaling from the CELL SURFACE RECEPTORS. The CD45 antigens occur as multiple isoforms that result from alternative mRNA splicing and differential usage of three exons.
Cell-surface glycoprotein beta-chains that are non-covalently linked to specific alpha-chains of the CD11 family of leukocyte-adhesion molecules (RECEPTORS, LEUKOCYTE-ADHESION). A defect in the gene encoding CD18 causes LEUKOCYTE-ADHESION DEFICIENCY SYNDROME.
55-kDa antigens found on HELPER-INDUCER T-LYMPHOCYTES and on a variety of other immune cell types. CD4 antigens are members of the immunoglobulin supergene family and are implicated as associative recognition elements in MAJOR HISTOCOMPATIBILITY COMPLEX class II-restricted immune responses. On T-lymphocytes they define the helper/inducer subset. CD4 antigens also serve as INTERLEUKIN-15 receptors and bind to the HIV receptors, binding directly to the HIV ENVELOPE PROTEIN GP120.
A subclass of HLA-D antigens that consist of alpha and beta chains. The inheritance of HLA-DR antigens differs from that of the HLA-DQ ANTIGENS and HLA-DP ANTIGENS.
The number of WHITE BLOOD CELLS per unit volume in venous BLOOD. A differential leukocyte count measures the relative numbers of the different types of white cells.
A MANNOSE/GLUCOSE binding lectin isolated from the jack bean (Canavalia ensiformis). It is a potent mitogen used to stimulate cell proliferation in lymphocytes, primarily T-lymphocyte, cultures.
Manifestations of the immune response which are mediated by antigen-sensitized T-lymphocytes via lymphokines or direct cytotoxicity. This takes place in the absence of circulating antibody or where antibody plays a subordinate role.
Conditions in which there is histological damage to the lower epidermis along with a grouped chronic inflammatory infiltrate in the papillary dermis disturbing the interface between the epidermis and dermis. LICHEN PLANUS is the prototype of all lichenoid eruptions. (From Rook et al., Textbook of Dermatology, 4th ed, p398)
The type species of LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte.
A CELL LINE derived from human T-CELL LEUKEMIA and used to determine the mechanism of differential susceptibility to anti-cancer drugs and radiation.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
A sialic acid-rich protein and an integral cell membrane mucin. It plays an important role in activation of T-LYMPHOCYTES.
Bone marrow-derived lymphocytes that possess cytotoxic properties, classically directed against transformed and virus-infected cells. Unlike T CELLS; and B CELLS; NK CELLS are not antigen specific. The cytotoxicity of natural killer cells is determined by the collective signaling of an array of inhibitory and stimulatory CELL SURFACE RECEPTORS. A subset of T-LYMPHOCYTES referred to as NATURAL KILLER T CELLS shares some of the properties of this cell type.
The demonstration of the cytotoxic effect on a target cell of a lymphocyte, a mediator released by a sensitized lymphocyte, an antibody, or complement.
The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood MONOCYTES. Main types are PERITONEAL MACROPHAGES; ALVEOLAR MACROPHAGES; HISTIOCYTES; KUPFFER CELLS of the liver; and OSTEOCLASTS. They may further differentiate within chronic inflammatory lesions to EPITHELIOID CELLS or may fuse to form FOREIGN BODY GIANT CELLS or LANGHANS GIANT CELLS. (from The Dictionary of Cell Biology, Lackie and Dow, 3rd ed.)
The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.
Immunosuppression by reduction of circulating lymphocytes or by T-cell depletion of bone marrow. The former may be accomplished in vivo by thoracic duct drainage or administration of antilymphocyte serum. The latter is performed ex vivo on bone marrow before its transplantation.
The altered state of immunologic responsiveness resulting from initial contact with antigen, which enables the individual to produce antibodies more rapidly and in greater quantity in response to secondary antigenic stimulus.
A member of the tumor necrosis factor receptor superfamily that may play a role in the regulation of NF-KAPPA B and APOPTOSIS. They are found on activated T-LYMPHOCYTES; B-LYMPHOCYTES; NEUTROPHILS; EOSINOPHILS; MAST CELLS and NK CELLS. Overexpression of CD30 antigen in hematopoietic malignancies make the antigen clinically useful as a biological tumor marker. Signaling of the receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.
Large, transmembrane, non-covalently linked glycoproteins (alpha and beta). Both chains can be polymorphic although there is more structural variation in the beta chains. The class II antigens in humans are called HLA-D ANTIGENS and are coded by a gene on chromosome 6. In mice, two genes named IA and IE on chromosome 17 code for the H-2 antigens. The antigens are found on B-lymphocytes, macrophages, epidermal cells, and sperm and are thought to mediate the competence of and cellular cooperation in the immune response. The term IA antigens used to refer only to the proteins encoded by the IA genes in the mouse, but is now used as a generic term for any class II histocompatibility antigen.
Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
A soluble factor produced by activated T-LYMPHOCYTES that induces the expression of MHC CLASS II GENES and FC RECEPTORS on B-LYMPHOCYTES and causes their proliferation and differentiation. It also acts on T-lymphocytes, MAST CELLS, and several other hematopoietic lineage cells.
Unglycosylated phosphoproteins expressed only on B-cells. They are regulators of transmembrane Ca2+ conductance and thought to play a role in B-cell activation and proliferation.
Sites on an antigen that interact with specific antibodies.
The transfer of lymphocytes from a donor to a recipient or reinfusion to the donor.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
A cell adhesion protein that was originally identified as a heat stable antigen in mice. It is involved in METASTASIS and is highly expressed in many NEOPLASMS.
T-cell enhancement of the B-cell response to thymic-dependent antigens.
Oligosaccharide antigenic determinants found principally on NK cells and T-cells. Their role in the immune response is poorly understood.
Differentiation antigens expressed on pluripotential hematopoietic cells, most human thymocytes, and a major subset of peripheral blood T-lymphocytes. They have been implicated in integrin-mediated cellular adhesion and as signalling receptors on T-cells.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
A group of three different alpha chains (CD11a, CD11b, CD11c) that are associated with an invariant CD18 beta chain (ANTIGENS, CD18). The three resulting leukocyte-adhesion molecules (RECEPTORS, LEUKOCYTE ADHESION) are LYMPHOCYTE FUNCTION-ASSOCIATED ANTIGEN-1; MACROPHAGE-1 ANTIGEN; and ANTIGEN, P150,95.
Antigenic determinants recognized and bound by the T-cell receptor. Epitopes recognized by the T-cell receptor are often located in the inner, unexposed side of the antigen, and become accessible to the T-cell receptors after proteolytic processing of the antigen.
Subset of helper-inducer T-lymphocytes which synthesize and secrete interleukin-2, gamma-interferon, and interleukin-12. Due to their ability to kill antigen-presenting cells and their lymphokine-mediated effector activity, Th1 cells are associated with vigorous delayed-type hypersensitivity reactions.
Substances that stimulate mitosis and lymphocyte transformation. They include not only substances associated with LECTINS, but also substances from streptococci (associated with streptolysin S) and from strains of alpha-toxin-producing staphylococci. (Stedman, 25th ed)
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Leukocyte differentiation antigens and major platelet membrane glycoproteins present on MONOCYTES; ENDOTHELIAL CELLS; PLATELETS; and mammary EPITHELIAL CELLS. They play major roles in CELL ADHESION; SIGNAL TRANSDUCTION; and regulation of angiogenesis. CD36 is a receptor for THROMBOSPONDINS and can act as a scavenger receptor that recognizes and transports oxidized LIPOPROTEINS and FATTY ACIDS.
The in vitro formation of clusters consisting of a cell (usually a lymphocyte) surrounded by antigenic cells or antigen-bearing particles (usually erythrocytes, which may or may not be coated with antibody or antibody and complement). The rosette-forming cell may be an antibody-forming cell, a memory cell, a T-cell, a cell bearing surface cytophilic antibodies, or a monocyte possessing Fc receptors. Rosette formation can be used to identify specific populations of these cells.
A subtype of tetraspanin proteins that play a role in cell adhesion, cell motility, and tumor metastasis. CD9 antigens take part in the process of platelet activation and aggregation, the formation of paranodal junctions in neuronal tissue, and the fusion of sperm with egg.
Elements of limited time intervals, contributing to particular results or situations.
An integrin heterodimer widely expressed on cells of hematopoietic origin. CD11A ANTIGEN comprises the alpha chain and the CD18 antigen (ANTIGENS, CD18) the beta chain. Lymphocyte function-associated antigen-1 is a major receptor of T-CELLS; B-CELLS; and GRANULOCYTES. It mediates the leukocyte adhesion reactions underlying cytolytic conjugate formation, helper T-cell interactions, and antibody-dependent killing by NATURAL KILLER CELLS and granulocytes. Intracellular adhesion molecule-1 has been defined as a ligand for lymphocyte function-associated antigen-1.
Cell surface glycoproteins on lymphocytes and other leukocytes that mediate adhesion to specialized blood vessels called high endothelial venules. Several different classes of lymphocyte homing receptors have been identified, and they appear to target different surface molecules (addressins) on high endothelial venules in different tissues. The adhesion plays a crucial role in the trafficking of lymphocytes.
Large, phagocytic mononuclear leukocytes produced in the vertebrate BONE MARROW and released into the BLOOD; contain a large, oval or somewhat indented nucleus surrounded by voluminous cytoplasm and numerous organelles.
The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.
The process by which antigen is presented to lymphocytes in a form they can recognize. This is performed by antigen presenting cells (APCs). Some antigens require processing before they can be recognized. Antigen processing consists of ingestion and partial digestion of the antigen by the APC, followed by presentation of fragments on the cell surface. (From Rosen et al., Dictionary of Immunology, 1989)
Small glycoproteins found on both hematopoietic and non-hematopoietic cells. CD59 restricts the cytolytic activity of homologous complement by binding to C8 and C9 and blocking the assembly of the membrane attack complex. (From Barclay et al., The Leukocyte Antigen FactsBook, 1993, p234)
Mature LYMPHOCYTES and MONOCYTES transported by the blood to the body's extravascular space. They are morphologically distinguishable from mature granulocytic leukocytes by their large, non-lobed nuclei and lack of coarse, heavily stained cytoplasmic granules.
A transmembrane protein belonging to the tumor necrosis factor superfamily that specifically binds to CD27 ANTIGEN. It is found on activated T-LYMPHOCYTES; B-LYMPHOCYTES; and DENDRITIC CELLS where it plays a role in stimulating the proliferation of CD4-POSITIVE T-LYMPHOCYTES and CD8-POSITIVE T-LYMPHOCYTES.
Proteins, glycoprotein, or lipoprotein moieties on surfaces of tumor cells that are usually identified by monoclonal antibodies. Many of these are of either embryonic or viral origin.
Glycoproteins found on the membrane or surface of cells.
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
A heterogeneous group of immunocompetent cells that mediate the cellular immune response by processing and presenting antigens to the T-cells. Traditional antigen-presenting cells include MACROPHAGES; DENDRITIC CELLS; LANGERHANS CELLS; and B-LYMPHOCYTES. FOLLICULAR DENDRITIC CELLS are not traditional antigen-presenting cells, but because they hold antigen on their cell surface in the form of IMMUNE COMPLEXES for B-cell recognition they are considered so by some authors.
A specific HLA-A surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-A*02 allele family.
A ubiquitously expressed membrane glycoprotein. It interacts with a variety of INTEGRINS and mediates responses to EXTRACELLULAR MATRIX PROTEINS.
A CD antigen that contains a conserved I domain which is involved in ligand binding. When combined with CD18 the two subunits form MACROPHAGE-1 ANTIGEN.
A ubiquitously expressed complement receptor that binds COMPLEMENT C3B and COMPLEMENT C4B and serves as a cofactor for their inactivation. CD46 also interacts with a wide variety of pathogens and mediates immune response.
One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.
A calcium-dependent pore-forming protein synthesized in cytolytic LYMPHOCYTES and sequestered in secretory granules. Upon immunological reaction between a cytolytic lymphocyte and a target cell, perforin is released at the plasma membrane and polymerizes into transmembrane tubules (forming pores) which lead to death of a target cell.
A subclass of winged helix DNA-binding proteins that share homology with their founding member fork head protein, Drosophila.
T-cell receptors composed of CD3-associated gamma and delta polypeptide chains and expressed primarily in CD4-/CD8- T-cells. The receptors appear to be preferentially located in epithelial sites and probably play a role in the recognition of bacterial antigens. The T-cell receptor gamma/delta chains are separate and not related to the gamma and delta chains which are subunits of CD3 (see ANTIGENS, CD3).
Membrane glycoproteins consisting of an alpha subunit and a BETA 2-MICROGLOBULIN beta subunit. In humans, highly polymorphic genes on CHROMOSOME 6 encode the alpha subunits of class I antigens and play an important role in determining the serological specificity of the surface antigen. Class I antigens are found on most nucleated cells and are generally detected by their reactivity with alloantisera. These antigens are recognized during GRAFT REJECTION and restrict cell-mediated lysis of virus-infected cells.
Substances that are recognized by the immune system and induce an immune reaction.
The specific failure of a normally responsive individual to make an immune response to a known antigen. It results from previous contact with the antigen by an immunologically immature individual (fetus or neonate) or by an adult exposed to extreme high-dose or low-dose antigen, or by exposure to radiation, antimetabolites, antilymphocytic serum, etc.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.
Glycoproteins with a wide distribution on hematopoietic and non-hematopoietic cells and strongly expressed on macrophages. CD58 mediates cell adhesion by binding to CD2; (ANTIGENS, CD2); and this enhances antigen-specific T-cell activation.
The major group of transplantation antigens in the mouse.
The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.
A group of antigens that includes both the major and minor histocompatibility antigens. The former are genetically determined by the major histocompatibility complex. They determine tissue type for transplantation and cause allograft rejections. The latter are systems of allelic alloantigens that can cause weak transplant rejection.
A member of the tumor necrosis factor receptor superfamily that is specific for 4-1BB LIGAND. It is found in a variety of immune cell types including activated T-LYMPHOCYTES; NATURAL KILLER CELLS; and DENDRITIC CELLS. Activation of the receptor on T-LYMPHOCYTES plays a role in their expansion, production of cytokines and survival. Signaling by the activated receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.
Specialized tissues that are components of the lymphatic system. They provide fixed locations within the body where a variety of LYMPHOCYTES can form, mature and multiply. The lymphoid tissues are connected by a network of LYMPHATIC VESSELS.
Tetraspanin proteins that are involved in a variety of cellular functions including BASEMENT MEMBRANE assembly, and in the formation of a molecular complexes on the surface of LYMPHOCYTES.
Multi-subunit proteins which function in IMMUNITY. They are produced by B LYMPHOCYTES from the IMMUNOGLOBULIN GENES. They are comprised of two heavy (IMMUNOGLOBULIN HEAVY CHAINS) and two light chains (IMMUNOGLOBULIN LIGHT CHAINS) with additional ancillary polypeptide chains depending on their isoforms. The variety of isoforms include monomeric or polymeric forms, and transmembrane forms (B-CELL ANTIGEN RECEPTORS) or secreted forms (ANTIBODIES). They are divided by the amino acid sequence of their heavy chains into five classes (IMMUNOGLOBULIN A; IMMUNOGLOBULIN D; IMMUNOGLOBULIN E; IMMUNOGLOBULIN G; IMMUNOGLOBULIN M) and various subclasses.
Proteins secreted from an organism which form membrane-spanning pores in target cells to destroy them. This is in contrast to PORINS and MEMBRANE TRANSPORT PROTEINS that function within the synthesizing organism and COMPLEMENT immune proteins. These pore forming cytotoxic proteins are a form of primitive cellular defense which are also found in human LYMPHOCYTES.
Form of adoptive transfer where cells with antitumor activity are transferred to the tumor-bearing host in order to mediate tumor regression. The lymphoid cells commonly used are lymphokine-activated killer (LAK) cells and tumor-infiltrating lymphocytes (TIL). This is usually considered a form of passive immunotherapy. (From DeVita, et al., Cancer, 1993, pp.305-7, 314)
A transmembrane protein belonging to the tumor necrosis factor superfamily that was originally discovered on cells of the lymphoid-myeloid lineage, including activated T-LYMPHOCYTES and NATURAL KILLER CELLS. It plays an important role in immune homeostasis and cell-mediated toxicity by binding to the FAS RECEPTOR and triggering APOPTOSIS.
Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.
IMMUNOGLOBULINS on the surface of B-LYMPHOCYTES. Their MESSENGER RNA contains an EXON with a membrane spanning sequence, producing immunoglobulins in the form of type I transmembrane proteins as opposed to secreted immunoglobulins (ANTIBODIES) which do not contain the membrane spanning segment.
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
Form of passive immunization where previously sensitized immunologic agents (cells or serum) are transferred to non-immune recipients. When transfer of cells is used as a therapy for the treatment of neoplasms, it is called adoptive immunotherapy (IMMUNOTHERAPY, ADOPTIVE).
Includes the spectrum of human immunodeficiency virus infections that range from asymptomatic seropositivity, thru AIDS-related complex (ARC), to acquired immunodeficiency syndrome (AIDS).
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
A family of serine endopeptidases found in the SECRETORY GRANULES of LEUKOCYTES such as CYTOTOXIC T-LYMPHOCYTES and NATURAL KILLER CELLS. When secreted into the intercellular space granzymes act to eliminate transformed and virus-infected host cells.
Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.
Cell surface molecules on cells of the immune system that specifically bind surface molecules or messenger molecules and trigger changes in the behavior of cells. Although these receptors were first identified in the immune system, many have important functions elsewhere.
An integrin alpha subunit of approximately 150-kDa molecular weight. It is expressed at high levels on monocytes and combines with CD18 ANTIGEN to form the cell surface receptor INTEGRIN ALPHAXBETA2. The subunit contains a conserved I-domain which is characteristic of several of alpha integrins.
Cell adhesion molecules present on virtually all monocytes, platelets, and granulocytes. CD31 is highly expressed on endothelial cells and concentrated at the junctions between them.
A class of lymphocytes characterized by the lack of surface markers specific for either T or B lymphocytes.
Adherence of cells to surfaces or to other cells.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
A technique of culturing mixed cell types in vitro to allow their synergistic or antagonistic interactions, such as on CELL DIFFERENTIATION or APOPTOSIS. Coculture can be of different types of cells, tissues, or organs from normal or disease states.
The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.
A method for the detection of very small quantities of antibody in which the antigen-antibody-complement complex adheres to indicator cells, usually primate erythrocytes or nonprimate blood platelets. The reaction is dependent on the number of bound C3 molecules on the C3b receptor sites of the indicator cell.
A round-to-oval mass of lymphoid tissue embedded in the lateral wall of the PHARYNX. There is one on each side of the oropharynx in the fauces between the anterior and posterior pillars of the SOFT PALATE.
All of the processes involved in increasing CELL NUMBER including CELL DIVISION.
A chronic systemic disease, primarily of the joints, marked by inflammatory changes in the synovial membranes and articular structures, widespread fibrinoid degeneration of the collagen fibers in mesenchymal tissues, and by atrophy and rarefaction of bony structures. Etiology is unknown, but autoimmune mechanisms have been implicated.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
GPI-linked membrane proteins broadly distributed among hematopoietic and non-hematopoietic cells. CD55 prevents the assembly of C3 CONVERTASE or accelerates the disassembly of preformed convertase, thus blocking the formation of the membrane attack complex.
Substances elaborated by viruses that have antigenic activity.
An alpha-integrin subunit found on lymphocytes, granulocytes, macrophages and monocytes. It combines with the integrin beta2 subunit (CD18 ANTIGEN) to form LYMPHOCYTE FUNCTION-ASSOCIATED ANTIGEN-1.
A specific immune response elicited by a specific dose of an immunologically active substance or cell in an organism, tissue, or cell.
The genetic region which contains the loci of genes which determine the structure of the serologically defined (SD) and lymphocyte-defined (LD) TRANSPLANTATION ANTIGENS, genes which control the structure of the IMMUNE RESPONSE-ASSOCIATED ANTIGENS, HUMAN; the IMMUNE RESPONSE GENES which control the ability of an animal to respond immunologically to antigenic stimuli, and genes which determine the structure and/or level of the first four components of complement.
Reduction in the number of lymphocytes.
The movement of leukocytes in response to a chemical concentration gradient or to products formed in an immunologic reaction.
A membrane-bound tumor necrosis family member found primarily on activated T-LYMPHOCYTES that binds specifically to CD30 ANTIGEN. It may play a role in INFLAMMATION and immune regulation.
Deliberate stimulation of the host's immune response. ACTIVE IMMUNIZATION involves administration of ANTIGENS or IMMUNOLOGIC ADJUVANTS. PASSIVE IMMUNIZATION involves administration of IMMUNE SERA or LYMPHOCYTES or their extracts (e.g., transfer factor, immune RNA) or transplantation of immunocompetent cell producing tissue (thymus or bone marrow).
Leukemia associated with HYPERPLASIA of the lymphoid tissues and increased numbers of circulating malignant LYMPHOCYTES and lymphoblasts.
Polymorphic class I human histocompatibility (HLA) surface antigens present on almost all nucleated cells. At least 20 antigens have been identified which are encoded by the A locus of multiple alleles on chromosome 6. They serve as targets for T-cell cytolytic responses and are involved with acceptance or rejection of tissue/organ grafts.
A class of immunoglobulin bearing mu chains (IMMUNOGLOBULIN MU-CHAINS). IgM can fix COMPLEMENT. The name comes from its high molecular weight and originally being called a macroglobulin.
Tetraspanin proteins found associated with LAMININ-binding INTEGRINS. The CD151 antigens may play a role in the regulation of CELL MOTILITY.
Antigens determined by leukocyte loci found on chromosome 6, the major histocompatibility loci in humans. They are polypeptides or glycoproteins found on most nucleated cells and platelets, determine tissue types for transplantation, and are associated with certain diseases.
Cell adhesion molecule and CD antigen that serves as a homing receptor for lymphocytes to lymph node high endothelial venules.
Proteins prepared by recombinant DNA technology.
Any of several ways in which living cells of an organism communicate with one another, whether by direct contact between cells or by means of chemical signals carried by neurotransmitter substances, hormones, and cyclic AMP.
An inhibitory T CELL receptor that is closely related to CD28 ANTIGEN. It has specificity for CD80 ANTIGEN and CD86 ANTIGEN and acts as a negative regulator of peripheral T cell function. CTLA-4 antigen is believed to play role in inducing PERIPHERAL TOLERANCE.
This enzyme is a lymphoid-specific src family tyrosine kinase that is critical for T-cell development and activation. Lck is associated with the cytoplasmic domains of CD4, CD8 and the beta-chain of the IL-2 receptor, and is thought to be involved in the earliest steps of TCR-mediated T-cell activation.
Mice homozygous for the mutant autosomal recessive gene "scid" which is located on the centromeric end of chromosome 16. These mice lack mature, functional lymphocytes and are thus highly susceptible to lethal opportunistic infections if not chronically treated with antibiotics. The lack of B- and T-cell immunity resembles severe combined immunodeficiency (SCID) syndrome in human infants. SCID mice are useful as animal models since they are receptive to implantation of a human immune system producing SCID-human (SCID-hu) hematochimeric mice.
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
White blood cells. These include granular leukocytes (BASOPHILS; EOSINOPHILS; and NEUTROPHILS) as well as non-granular leukocytes (LYMPHOCYTES and MONOCYTES).
Proteins isolated from the roots of the pokeweed, Phytolacca americana, that agglutinate some erythrocytes, stimulate mitosis and antibody synthesis in lymphocytes, and induce activation of plasma cells.
A class of animal lectins that bind to carbohydrate in a calcium-dependent manner. They share a common carbohydrate-binding domain that is structurally distinct from other classes of lectins.
Manipulation of the host's immune system in treatment of disease. It includes both active and passive immunization as well as immunosuppressive therapy to prevent graft rejection.
Serum glycoprotein produced by activated MACROPHAGES and other mammalian MONONUCLEAR LEUKOCYTES. It has necrotizing activity against tumor cell lines and increases ability to reject tumor transplants. Also known as TNF-alpha, it is only 30% homologous to TNF-beta (LYMPHOTOXIN), but they share TNF RECEPTORS.
An increased reactivity to specific antigens mediated not by antibodies but by cells.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
Ubiquitously-expressed tetraspanin proteins that are found in late ENDOSOMES and LYSOSOMES and have been implicated in intracellular transport of proteins.
Zinc-binding metalloproteases that are members of the type II integral membrane metalloproteases. They are expressed by GRANULOCYTES; MONOCYTES; and their precursors as well as by various non-hematopoietic cells. They release an N-terminal amino acid from a peptide, amide or arylamide.
The type species of LYMPHOCRYPTOVIRUS, subfamily GAMMAHERPESVIRINAE, infecting B-cells in humans. It is thought to be the causative agent of INFECTIOUS MONONUCLEOSIS and is strongly associated with oral hairy leukoplakia (LEUKOPLAKIA, HAIRY;), BURKITT LYMPHOMA; and other malignancies.
Syndromes in which there is a deficiency or defect in the mechanisms of immunity, either cellular or humoral.
Cells contained in the bone marrow including fat cells (see ADIPOCYTES); STROMAL CELLS; MEGAKARYOCYTES; and the immediate precursors of most blood cells.
A positive regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins.
Progenitor cells from which all blood cells derive.
Disorders that are characterized by the production of antibodies that react with host tissues or immune effector cells that are autoreactive to endogenous peptides.
Deliberate prevention or diminution of the host's immune response. It may be nonspecific as in the administration of immunosuppressive agents (drugs or radiation) or by lymphocyte depletion or may be specific as in desensitization or the simultaneous administration of antigen and immunosuppressive drugs.
Molecule composed of the non-covalent association of the T-cell antigen receptor (RECEPTORS, ANTIGEN, T-CELL) with the CD3 complex (ANTIGENS, CD3). This association is required for the surface expression and function of both components. The molecule consists of up to seven chains: either the alpha/beta or gamma/delta chains of the T-cell receptor, and four or five chains in the CD3 complex.
A low affinity interleukin-2 receptor subunit that combines with the INTERLEUKIN-2 RECEPTOR BETA SUBUNIT and the INTERLEUKIN RECEPTOR COMMON GAMMA-CHAIN to form a high affinity receptor for INTERLEUKIN-2.
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.

Analysis of the adult thymus in reconstitution of T lymphocytes in HIV-1 infection. (1/17664)

A key question in understanding the status of the immune system in HIV-1 infection is whether the adult thymus contributes to reconstitution of peripheral T lymphocytes. We analyzed the thymus in adult patients who died of HIV-1 infection. In addition, we studied the clinical course of HIV-1 infection in three patients thymectomized for myasthenia gravis and determined the effect of antiretroviral therapy on CD4(+) T cells. We found that five of seven patients had thymus tissue at autopsy and that all thymuses identified had inflammatory infiltrates surrounding lymphodepleted thymic epithelium. Two of seven patients also had areas of thymopoiesis; one of these patients had peripheral blood CD4(+) T-cell levels of <50/mm3 for 51 months prior to death. Of three thymectomized patients, one rapidly progressed to AIDS, one progressed to AIDS over seven years (normal progressor), whereas the third remains asymptomatic at least seven years after seroconversion. Both latter patients had rises in peripheral blood CD4(+) T cells after antiretroviral therapy. Most patients who died of complications of HIV-1 infection did not have functional thymus tissue, and when present, thymopoiesis did not prevent prolonged lymphopenia. Thymectomy before HIV-1 infection did not preclude either peripheral CD4(+) T-cell rises or clinical responses after antiretroviral therapy.  (+info)

Thymic selection by a single MHC/peptide ligand: autoreactive T cells are low-affinity cells. (2/17664)

In H2-M- mice, the presence of a single peptide, CLIP, bound to MHC class II molecules generates a diverse repertoire of CD4+ cells. In these mice, typical self-peptides are not bound to class II molecules, with the result that a very high proportion of H2-M- CD4+ cells are responsive to the various peptides displayed on normal MHC-compatible APC. We show here, however, that such "self" reactivity is controlled by low-affinity CD4+ cells. These cells give spectacularly high proliferative responses but are virtually unreactive in certain other assays, e.g., skin graft rejection; responses to MHC alloantigens, by contrast, are intense in all assays. Possible explanations for why thymic selection directed to a single peptide curtails self specificity without affecting alloreactivity are discussed.  (+info)

Clearance of Chlamydia trachomatis from the murine genital mucosa does not require perforin-mediated cytolysis or Fas-mediated apoptosis. (3/17664)

The molecular mechanisms of resistance to genital infection with the mouse pneumonitis (MoPn) strain of Chlamydia trachomatis are unknown. A role for major histocompatibility complex class II-restricted, interleukin-12-dependent CD4(+) T cells has been established, but the functional activity of these cells does not depend on secretion of gamma interferon. Here we examined the potential contribution of T-cell-mediated cytotoxicity and apoptosis to mucosal clearance of MoPn by using mice deficient in the molecular mediators of target cell lysis. Animals lacking perforin, Fas, Fas ligand, or both perforin and Fas ligand were infected genitally with C. trachomatis MoPn and monitored for expression of immunity to chlamydial antigens and clearance of MoPn from the genital mucosa. In each case, the profile of spleen cytokine production, the magnitude of the host antibody response, and the kinetics of chlamydial clearance were similar to those of genetically intact controls. Compensatory overproduction of tumor necrosis factor alpha, an alternate mediator of apoptosis in certain cell types, did not appear to account for the ability of mutant mice to resolve Chlamydia infections. These results fail to support CD4(+) T-cell-mediated apoptosis or CD8(+) T-cell-mediated cytotoxicity as being critical to the clearance of C. trachomatis MoPn urogenital infections.  (+info)

Fas and Fas ligand interaction induces apoptosis in inflammatory myopathies: CD4+ T cells cause muscle cell injury directly in polymyositis. (4/17664)

OBJECTIVE: To investigate the involvement of the Fas/Fas ligand (Fas/FasL) system in the inflammatory myopathies. METHODS: Frozen muscle sections obtained from 7 patients with polymyositis (PM), 4 patients with dermatomyositis (DM), and 3 controls were studied by immunochemistry. Apoptosis was detected by DNA electrophoresis and in situ labeling using the TUNEL method. RESULTS: Fas was detected on muscle fibers and infiltrating mononuclear cells (MNC) in 6 PM patients and 2 DM patients. FasL was expressed mainly on CD4+ T cells and some CD8+ T cells, and on macrophages surrounding Fas-positive muscles in 4 PM patients and 1 DM patient. In 3 of the 5 patients with FasL-positive MNC, the TUNEL method showed that both invaded myonuclei and MNC underwent apoptosis. Chromosomal DNA from the muscle tissue of these patients showed ladder formation. CONCLUSION: Fas/FasL is involved in muscle cell apoptosis in at least 2 of the inflammatory myopathies, PM and DM. Although CD8+-mediated cytotoxicity is thought to be the main mechanism of muscle injury in PM, our data suggest that CD4+ T cells also directly cause muscle cell damage.  (+info)

Expanded tumor-reactive CD4+ T-cell responses to human cancers induced by secondary anti-CD3/anti-CD28 activation. (5/17664)

Generation of tumor-reactive T cells in large numbers ex vivo is a requisite step in the adoptive immunotherapy of patients. We examined the immune responses of T cells derived from tumor vaccine-primed lymph nodes activated with anti-CD3 alone and with an anti-CD3/anti-CD28 combination. Nylon wool-purified CD3+ cells were isolated from vaccine-primed lymph nodes obtained from melanoma, renal cell, and head and neck cancer patients. In the absence of antigen-presenting cells, activation with anti-CD3/anti-CD28 greatly enhanced subsequent T-cell expansion in interleukin 2 (>100-fold), compared to anti-CD3 alone. CD4+ T cells were preferentially stimulated. In four of eight patients, we found evidence of CD4+ cellular responses to autologous tumors by cytokine release assays. Positively selected CD4+ cells activated with anti-CD3/anti-CD28 released greater amounts of cytokine (IFN-gamma and granulocyte macrophage colony-stimulating factor) in response to autologous tumors compared to cells activated by anti-CD3 alone. The CD4+ reactivity was MHC class II restricted and appeared to be associated with the expression of class II molecules on the vaccinating tumor cells. The CD4+ T-cell responses to class II-restricted tumor-associated antigens in patients with renal cell cancers represent unique findings.  (+info)

Chlamydia infections and heart disease linked through antigenic mimicry. (6/17664)

Chlamydia infections are epidemiologically linked to human heart disease. A peptide from the murine heart muscle-specific alpha myosin heavy chain that has sequence homology to the 60-kilodalton cysteine-rich outer membrane proteins of Chlamydia pneumoniae, C. psittaci, and C. trachomatis was shown to induce autoimmune inflammatory heart disease in mice. Injection of the homologous Chlamydia peptides into mice also induced perivascular inflammation, fibrotic changes, and blood vessel occlusion in the heart, as well as triggering T and B cell reactivity to the homologous endogenous heart muscle-specific peptide. Chlamydia DNA functioned as an adjuvant in the triggering of peptide-induced inflammatory heart disease. Infection with C. trachomatis led to the production of autoantibodies to heart muscle-specific epitopes. Thus, Chlamydia-mediated heart disease is induced by antigenic mimicry of a heart muscle-specific protein.  (+info)

T-cell expression of the human GATA-3 gene is regulated by a non-lineage-specific silencer. (7/17664)

The GATA-3 transcription factor is required for development of the T-cell lineage and Th2 cytokine gene expression in CD4 T-cells. We have mapped the DNase-I-hypersensitive (HS) regions of the human GATA-3 gene in T-cells and non-T-cells and studied their transcriptional activities. HS I-III, located 5' from the transcriptional initiation site, were found in hematopoietic and non-hematopoietic cells, whereas HS IV-VII, located 3' from the transcriptional start site, were exclusively observed in T-cells. Among these hypersensitive sites, two transcriptional control elements were found, one in the first intron of the GATA-3 gene and the other between 8.3 and 5.9 kilobases 5' from the GATA-3 transcriptional initiation site. The first intron acted as a strong transcriptional activator in a position-dependent manner and with no cell-type specificity. The upstream regulatory element could confer T-cell specificity to the GATA-3 promoter activity, and analysis of this region revealed a 707-base pair silencer that drastically inhibited GATA-3 promoter activity in non-T-cells. Two CAGGTG E-boxes, located at the 5'- and 3'-ends of the silencer, were necessary for this silencer activity. The 3'-CAGGTG E-box could bind USF proteins, the ubiquitous repressor ZEB, or the basic helix-loop-helix proteins E2A and HEB, and we showed that a competition between ZEB and E2A/HEB proteins is involved in the silencer activity.  (+info)

Phenotypic and functional characterization of CD8(+) T cell clones specific for a mouse cytomegalovirus epitope. (8/17664)

A series of CD8(+) T cell clones, specific for the IE1 epitope YPHFMPTNL, of the immediate-early protein 1 of the murine cytomegalovirus (MCMV) were generated in order to determine their protective activity against this infection and correlate their phenotypic markers with antiviral activity. We found that the adoptive transfer of three of these anti-MCMV CD8(+) T cell clones into irradiated naive mice resulted in protection against challenge, while another CD8(+) T cell clone, of the same specificity, failed to confer protection. The clones that conferred protection against lethal challenge reduced greatly viral replication in the lung and other organs of the mice. Using one of the protective anti-MCMV CD8(+) T cell clones we found that in order to be fully protective the cells had to be transferred to recipient mice no later than 1 day after MCMV challenge. The adoptive transfer of these CD8(+) T cell clones also protected CD4(+) T-cell-depleted mice. Phenotypic characterization of the anti-MCMV clones revealed that the nonprotective clone expressed very low levels of CD8 molecules and produced only small amounts of TNF-alpha upon antigenic stimulation. Most importantly, our current study demonstrates that this MHC class I-restricted IE1 epitope of MCMV is efficiently presented to CD8(+) T cell clones in vivo and further strengthens the possibility of the potential use of CD8(+) T cell clones as immunotherapeutic tools against cytomegalovirus-induced disease.  (+info)

Signaling through CD27 plays a role in T cell activation and memory. However, it is currently unknown how this costimulatory receptor influences CD4 effector T (Teff) cells in inflamed tissues. In the current study, we used a murine model of inducible self-antigen expression in the epidermis to elucidate the functional role of CD27 on autoreactive Teff cells. Expression of CD27 on Ag-specific Teff cells resulted in enhanced skin inflammation when compared with CD27-deficient Teff cells. CD27 signaling promoted the accumulation of IFN-γ and IL-2-producing T cells in skin draining lymph nodes in a cell-intrinsic fashion. Surprisingly, this costimulatory pathway had minimal effect on early T cell activation and proliferation. Instead, signaling through CD27 resulted in the progressive survival of Teff cells during the autoimmune response. Using BH3 profiling to assess mitochondrial cell priming, we found that CD27-deficient cells were equally as sensitive as CD27-sufficient cells to mitochondrial ...
Adoptive transfer of CD4+CD25+ T cells inhibits HSV-1-specific CD8+ T cell responses. Purified CD4+CD25+ and CD4+CD25− T cells (2 × 106/mouse) were adoptively transferred into WT B6 mice 24 h before HSV infection, and the immune response was measured on days 7 and 28 p.i. (A) On days 7 and 28 p.i., spleen cells were incubated with gB498-505, and CD8/IFN-γ production was measured by intracellular staining. The number shown in each plot is the mean percentage of IFN-γ-producing CD8+ T cells obtained from four mice per group. (B) The resulting decrease in IFN-γ-secreting CD8+ T cells in B6 mice after adoptive transfer of CD4+CD25+ T cells were also measured by a standard ELISPOT assay. On days 7 and 28 post HSV infection, spleen cells were analyzed for the number of IFN-γ-secreting CD8+ T cells in response to SSIEFARL peptide. The error bars represent the mean ± SD of four different mice in the same group. *P , 0.05 compared with HSV-infected B6 mice receiving no adoptive transfer. Without ...
Peripheral T cells, in absence of a thymus (4, 25) or when transferred to T cell-deficient hosts (5, 7, 26), are capable of considerable expansion. The sequential transfer of a T cell population into successive hosts has shown that one T cell can generate up to 1015 cells (7). This indicates that in a normal mouse, peripheral T cell division is limited by mechanisms that probably include resource competition and complex cell interactions (9). We studied the role of T cell interactions in the control of the number of peripheral CD4+ T cells. In particular, we investigated if CD25+CD4+ T cells, which exert regulatory functions (27, 28, 29, 30, 31, 32), could also govern peripheral CD4+ T cell homeostasis.. IL-2Rα−/− mutant mice are reported as a paradigm for perturbed lymphocyte homeostasis (10). The lack of the IL-2Rα was believed to impair AICD in vivo (10), to modify the balance between clonal expansion and cell death, resulting in the deregulation of both the size and content of the ...
Our data demonstrated that naive CD8 T cells expressed low levels of IL-15Rα and thus may be targets of IL-15 action. Therefore, the deficiency of naive CD8 T cells in IL-15−/− and IL-15Rα−/− mice may be due to effects on naive CD8 T cells, although thymic defects could also contribute. Nevertheless, our examination of the early CD8 T cell response to VSV infection indicated that a proportionately normal frequency of Ag-specific cells was present in IL-15−/− mice since the percentage of tetramer-positive cells was similar in IL-15−/− and normal mice 4 days after infection (Fig. 1⇑).. The increased levels of IL-15Rα expressed by activated and memory CD8 T cells were likely responsible for the observed IL-15 augmentation of the primary response and the induction of memory cell proliferation by IL-15. Although we observed that the defect in the primary response in IL-15−/− mice was more severe than that in IL-15Rα−/− mice, it is possible that IL-15 delivers signals via ...
Interleukin-2 (IL-2) stimulates both activated CD4+ and CD8+ T cells to proliferate. IL-2 signals through an identical receptor complex and promotes the same dose-dependent phosphorylation of the canonical transcription factor STAT5 in both cell types. Despite this, CD8+ T cells enter the S phase earlier and proliferate to a greater extent than do CD4+ T cells in response to IL-2. We identified distinct IL-2 signaling dynamics in CD4+ and CD8+ T cells. In IL-2-stimulated CD8+ T cells, STAT5 phosphorylation increased rapidly and was sustained for 6 hours. In contrast, CD4+ T cells had a biphasic response, with maxima at 15 min and 2 to 4 hours after stimulation. Both cell types required vesicular trafficking, but only CD4+ T cells required new protein synthesis to maintain high phosphorylation of STAT5. Two subunits of the IL-2 receptor, IL-2Rβ and IL-2Rγ, were twice as abundant in CD8+ T cells than in CD4+ T cells. Reduction of IL-2Rβ abundance by 50% was sufficient to convert CD8+ T cells to ...
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CD4+ T细胞的激活需要T细胞上的TCR和共受体(CD28或ICOS),抗原呈递细胞上的MHCII和共激活分子两对分子的分别,同时结合。仅其中一对的结合,无法产生有效的T细胞激活。理想的CD8+ T细胞激活则依赖于CD4+ T细胞的信号转导[28]。CD4+细胞可以在初级CD8 T细胞的初次免疫应答中给予帮助,并且在急性感染的后期维持CD8+ 记忆T细胞的活性。所以,CD4+ T的激活对于CD8+ T细胞的活动是有利的[29][30][31]。 相比于MHC分子上的抗原,抗原呈递细胞的共激活分子一般是由病原体的副产物、热休克蛋白或者坏死的细胞碎片诱导表达的。共刺激机制被认为可以避免自体免疫的发生,因为即使T细胞错误地结合了自体抗原,也可能因为没有受到合适的共刺激而无法正常活化。一旦T细胞被正确地活化,它的细胞表面蛋白表达就会发生巨大的改变,活化T细胞的标志蛋白包括CD69,CD71,CD25 ...
CD4+ T cells play a major role in adaptive immune responses to intracellular and extracellular microbes by regulating the functions of B cells, CD8+ T cells, an...
How to Build Up T‐Cells in Your Body. If youd like to improve your immune system, work on increasing the number of t-cells in your body. T-cells are a type of lymphocyte that will attack cells that are infected with a virus. To improve y...
Changes of CD8/HLADR+ T cells during a period of seven years HAART ( ± SD,/ μL). Patient numbers: Effective group (A) (n = 25), Ineffective group (B) (n = 18)
But does Rove really think Palin will jump in, thats shes effectively in pre-campaign mode? Sure, shes acting like a candidate, but shes done that a lot already. Think back to the bus tour. What she craves is not so much political office but attention (and an enhancement to her celebrity status, and, of course, money), and she gets a ton of attention by tantalizing us with a possible presidential run. Its an old story by now, and we shouldnt be taken in by it. Palin can appear to be on the campaign trail, can go to Iowa and steal the spotlight, and can offer herself as GOP kingmaker -- for Perry, one would think, who gives her a way out, as she has said all along that she wouldnt run if someone else suitable were to run instead, and the two are very much on the same page. That doesnt mean shes running, just that shes being herself ...
The authors have demonstrated compartment differences between T cell immunity in the bronchoalveolar space and the periphery. These include a predominant presence of effector memory T cells and regulatory CD4+ T cells in BAL, and a higher percentage frequency of antigen-specific CD4+ T cells against influenza virus, S pneumoniae and M tuberculosis in BAL compared to peripheral blood. Our data has also demonstrated that HIV-infected individuals have impaired pulmonary CD4+ T cell immunity, which is characterised by lower proportions of total CD4+ T cells and impaired antigen-specific BAL CD4+ T cell response to influenza virus and M tuberculosis antigens.. Consistent with previous observations,21 we noticed that BAL CD4+ and CD8+ T cells were predominantly of effector memory phenotype irrespective of HIV status, while peripheral blood T cell phenotypes were distributed among naive, central memory, effector memory and terminal effector. Effector memory T cells migrate to the lung following antigen ...
Interleukin (IL)-4 is considered to be essential for T helper (Th)2 cell development, yet in areas of primary T cell activation, CD4+ cells are its only source. This implies that other signals must drive the initial expression of IL-4 production. The role of CD28 co-stimulation in Th2 subset development has been described. However, in mice deficient for CD28, Th2 responses are diminished, but not abrogated. Cytokines produced within the lymphoid tissue, e.g. IL-7, may be important in the primary activation of naive CD4+ cells. We have found that human naive CD4+ cells purified from umbilical cord blood express the IL-7 receptor and respond vigorously to IL-7 during primary stimulation. Naive CD4+ cells grown in IL-4, in the presence or absence of IL-2, fail to produce Th2 cytokines upon restimulation. In contrast, IL-7 induces development of a population of T cells that produce large amounts of IL-4. Growth in IL-7 also increases IL-2-induced production of interferon (IFN)-gamma and IL-10 production. IL
T cell dysfunction in the presence of ongoing antigen exposure is a cardinal feature of chronic viral infections with persistent high viremia, including HIV-1. Although interleukin-10 (IL-10) has been implicated as an important mediator of this T cell dysfunction, the regulation of IL-10 production in chronic HIV-1 infection remains poorly understood. We demonstrated that IL-10 is elevated in the plasma of individuals with chronic HIV-1 infection and that blockade of IL-10 signaling results in a restoration of HIV-1-specific CD4 T cell proliferation, gamma interferon (IFN-γ) secretion, and, to a lesser extent, IL-2 production. Whereas IL-10 blockade leads to restoration of IFN-γ secretion by HIV-1-specific CD4 T cells in all categories of subjects investigated, significant enhancement of IL-2 production and improved proliferation of CD4 T helper cells are restricted to viremic individuals. In peripheral blood mononuclear cells (PBMCs), this IL-10 is produced primarily by CD14(+) monocytes, but ...
It has been reported that a growing and heterogeneous group of regulatory cell modulate immune response. In particular, regulation of CD8+ T lymphocyte effector functions is critical for tissue homeostasis and immune tolerance control. Here, we report that the co-expression of CD3 and CD56 molecules identify a novel human regulatory T cell population exerting suppressive activity on proliferation, cytotoxicity and IFN- production of TCR-activated human CD8+ T lymphocytes. Regulatory functions of human circulating CD3+CD56+ T lymphocytes require cell-to-cell contact and are exerted in both autologous and allogeneic conditions. Of note, CD3+CD56+ T cells are reduced and functionally impaired in children affected by Type 1 Diabetes (T1D), at disease onset. Conversely the frequency of this cell subset is increased in patients with prostate cancer. Taken together, our findings reveal that freshly isolated human CD3+CD56+ cells specifically control activation of human CD8+ T lymphocytes. ...
T cells play a dominant role in the pathogenesis of asthma. Costimulation of T cells is necessary to fully activate them. An inducible costimulator (ICOS) of T cells is predominantly expressed on Th2 cells. Therefore, interference of signaling pathways precipitated by ICOS may present new therapeutic options for Th2 dominated diseases such as asthma. However, these signaling pathways are poorly characterized in vitro and in vivo. Human primary CD4+ T cells from blood were activated by beads with defined combinations of surface receptor stimulating antibodies and costimulatory receptor ligands. Real-time RT-PCR was used for measuring the production of cytokines from activated T cells. Activation of mitogen activated protein kinase (MAPK) signaling pathways leading to cytokine synthesis were investigated by western blot analysis and by specific inhibitors. The effect of inhibitors in vivo was tested in a murine asthma model of late phase eosinophilia. Lung inflammation was assessed by differential cell
We measured the frequency of clonally expanded and persistent T cells recognizing the immunodominant MBPp8599 epitope in subjects with typical relapsing remitting MS. Single T cells expressing mRNA transcripts encoding TCR-α and -β chains found in T cell clones previously isolated from these subjects recognizing the MBPp85-99 epitope were examined. In contrast to frequencies of 1 in 105 to 106 as measured by LDA, estimates of the T cell frequencies expressing TCR chain transcripts associated with MBPp8599 recognition were as high as 1 in 300.. In retrospect, the high frequencies of MBPp85-99-reactive T cells with presumed chronic stimulation is perhaps not surprising. Subjects with HTLV-I and HIV infection have high frequencies of virus reactive T cells as measured ex vivo in peripheral blood using direct cytotoxicity assays (25- 27). In contrast, the LDA analysis of CTL frequencies in HIV-infected patients which requires T cell expansion leads to an 100-fold underestimate of CTL effector ...
Activation of CD4+ T cells occurs through the simultaneous engagement of the T-cell receptor and a co-stimulatory molecule (like CD28, or ICOS) on the T cell by the major histocompatibility complex (MHCII) peptide and co-stimulatory molecules on the APC. Both are required for production of an effective immune response; in the absence of co-stimulation, T cell receptor signalling alone results in anergy. The signalling pathways downstream from co-stimulatory molecules usually engages the PI3K pathway generating PIP3 at the plasma membrane and recruiting PH domain containing signaling molecules like PDK1 that are essential for the activation of PKCθ, and eventual IL-2 production. Optimal CD8+ T cell response relies on CD4+ signalling.[33] CD4+ cells are useful in the initial antigenic activation of naïve CD8 T cells, and sustaining memory CD8+ T cells in the aftermath of an acute infection. Therefore, activation of CD4+ T cells can be beneficial to the action of CD8+ T cells.[34][35][36]. The ...
Activation of CD4+ T cells occurs through the simultaneous engagement of the T-cell receptor and a co-stimulatory molecule (like CD28, or ICOS) on the T cell by the major histocompatibility complex (MHCII) peptide and co-stimulatory molecules on the APC. Both are required for production of an effective immune response; in the absence of co-stimulation, T cell receptor signalling alone results in anergy. The signalling pathways downstream from co-stimulatory molecules usually engages the PI3K pathway generating PIP3 at the plasma membrane and recruiting PH domain containing signaling molecules like PDK1 that are essential for the activation of PKC-θ, and eventual IL-2 production. Optimal CD8+ T cell response relies on CD4+ signalling.[33] CD4+ cells are useful in the initial antigenic activation of naïve CD8 T cells, and sustaining memory CD8+ T cells in the aftermath of an acute infection. Therefore, activation of CD4+ T cells can be beneficial to the action of CD8+ T cells.[34][35][36] The ...
Islet-reactive CD8+ T cell frequencies in the pancreas, but not in blood, distinguish type 1 diabetic patients from healthy donors - Search Results - PubMed
Mark, there has been a number of discussions on this list regarding RA/RO... Im not going to rehash those discussions, since I dont want to bore everyone else. Go to the archives and read over the material -- it includes references. But once again, CD45RA+ cells are BOTH naive AND memory. You CANNOT use RA and/or RO to identify naive T cells without an additional marker such as CD62L, CD11a, CD27. As for Double-positive, it depends on how you define positive. Bright (true) RA+RO+ double positives are very rare in peripheral blood but common in active tissues (like tonsil). Cells positive for one and dull for the other are normal resting memory T cells. There are no double-negative cells that are viable. Percentages in the peripheral blood are meaningless for the simple reason that RA+ cells are a heterogeneous mixture of naive & memory. Especially the CD8s, where anywhere between 20 and 80% of RA+ cells can be memory. (In CD4, most (95%) are naive; however, in many disease states ...
The total number of T cells present in the antigen-specific pool at the site of priming is determined by three cell-intrinsic parameters: the proportion of T cells entering into the proliferating pool, their cycle activity, and their survival. In accordance with published data (2), we found that CD28 increased cell cycle entry as well as activity. Early studies also report that CD28 promotes the survival of activated T cells (3). From measuring [3H]thymidine incorporation at different time points after TCR stimulation, it was concluded that this prosurvival effect came into play at a late time point and in fact sustained the proliferative response. However, we demonstrate that CD28−/− T cells die in much higher frequency than wild-type T cells when making the transition from G1 to S for the first time. CD28 strongly promotes cell survival at this point, thus greatly increasing the proportion of cells taking part in further divisions. The prosurvival effect of CD28 has been attributed to ...
Systemic CD4+ T Cell Loss Resulting from Intravaginal HIV-1 Infection in Humanized BLT Mice(A) Comparison of the levels of CD4+ or CD8+ human T cells in the ind
Recently, growing evidences suggest that CD8+CD122+PD-1+ T cells are also a subset of Treg cells, which have more ability to suppress the allograft rejection and undergo faster homeostatic proliferation than conventional CD4+CD25+Foxp3+ Treg cells (31, 32, 40). subsets, and display enhanced functionality in terms of degranulation and cytokine production on a per-cell basis. Additionally, we have identified the novel splice junctions that use a high ratio of the non-canonical splicing motif GC-AG and found that AS is not a major contributor to the gene expression-level changes between paired pCD8 and dCD8 T cells. Together, our findings not only provide a comprehensive framework of the transcriptional and AS landscapes but also reveal the functional feature of human PF-05175157 dCD8 T cells, which are of great importance in understanding the biology of these cells and the physiology of human healthy pregnancy. mRNA transcript abundance (14, 15). As an ubiquitous and crucial mechanism to regulate ...
T cells play pivotal roles in shaping host immune responses in infectious diseases, autoimmunity and cancer. The activation of T cells requires immune and growth factor-derived signals. However, alterations in nutrients and metabolic signals tune T cell responses by impinging upon T cell fates and immune functions. In this review, we summarize how key nutrients, including glucose, amino acids and lipids, and their sensors and transporters shape T cell responses. We also briefly discuss regulation of T cell responses by oxygen and energy sensing mechanisms.
Tissue-resident memory T cells (T|sub|RM|/sub| cells) are crucial mediators of adaptive immunity in nonlymphoid tissues. However, the functional heterogeneity and pathogenic roles of CD4|sup|+|/sup| T|sub|RM|/sub| cells that reside within chronic inflammatory lesions remain unknown. We found that CD …
The immune system has evolved to fend off challenges from a wide array of pathogens while maintaining tolerance to self-antigens and benign environmental antigens. CD4 helper T cells are critical in regulating these processes with different subsets of CD4 T cells responsible for regulating different facets of the immune system. T helper 1 (Th1) cells, which contribute to antiviral immunity, and T helper 2 (Th2) cells, which contribute to antihelminth immunity and allergy, were the first CD4 T cell subsets to be discovered. Recently a number of new subsets have been discovered. Here we review what is known about CD4 T cell subsets with particular focus on neonatal immunity. ...
A major challenge in the HIV field has been to understand why the strength of virus-specific CD8 T cell responses has no relationship to viral load, and yet CD8 depletion studies indicate that these cells are critical for immune control. And a major challenge in the field of immunology in general has been the rapid translation of advances in murine models to humans. In late 2005, through a telephone conversation with Rafi Ahmed, we became aware of yet unpublished data in the mouse model of chronic infection. His laboratory had shown that in mice persistently infected with LCMV, T cells up-regulate a surface molecule termed PD-1, for programmed death-1, a negative immunoregulatory molecule that turned off CD8 T cell function. The potential parallels with HIV were immediately obvious to us-perhaps persistent exposure to HIV was having a similar impact on CD8 T cell function in humans, and perhaps similar immune regulation was rendering CD4 T cells exhausted as well.. We immediately formed a ...
Several immune cell subtypes were analyzed in HPV16-associated cancers by Chantal Duurland, PhD (Leiden University Medical Center) and colleagues. HPV+ patients have increased survival compared to HPV- patients, thus the role of the immune response to these cancers should be better elucidated. High levels of CD4+CD161+ infiltrating T cells have been found in HPV+ tumors; therefore, the authors used a multi-level approach to understanding the importance of this unique subset of CD4+ T cells in the HPV+ tumor microenvironment. The authors also described a population of CD14-CD33-CD163+ cells, which were identified as dendritic cells (DCs). This subset of DCs was found to associate with strong T cell infiltrates and improved patient survival, similar to CD4+CD161+ T cells. Thus, there was an effort to understand the crosstalk of these two immune subsets in HPV+ disease. Further analyses demonstrated that activated CD163+ DCs generated higher levels of both IL-12 and IL-18 compared to their CD163- ...
CD160 is an Ig-like glycoprotein expressed by the majority of circulating natural killer cells and γδ T cells. Whether CD160 could regulate CD8+
ECIA™ Intracellular cytokine staining assay is utilized to detect the antigen-specific T cell responses, immunogenic analysis, epitope discovery at a single cell level for both clinical studies and scientific researches.
Depending on the receptors on the surface of the macrophage, a T cell can distinguish the hepatitis virus from that of flu, without ever having seen before. T cells that belong to this category are called naive T cells. Naive T cells are the fresh troops, the virgin field of battle, called to intervene when we get sick we contract a new disease or a new infection. There are even T cells can recognize antigens produced in artificial laboratory that the human body has never encountered in millions of years of evolution. The type of T cell that recognizes the antigen is called the CD4 cell (also called CD4 helper T-cell or lymphocyte), one of the same name situated on its surface called receptors, in fact, CD4 receptor. Although not usually the cells that kill the invader, CD4 cells are the most important of the entire immune system. This is because their main function is to send signals that direct and mobilize other troops into battle. We should think of T-helper cells as troop commanders or ...
Unlike HIV-1-infected people, most HIV-2-infected subjects maintain a healthy CD4+ T cell count and a strong HIV-specific CD4+ T cell response. To define the cellular immunological correlates of good prognosis in HIV-2 infection, we conducted a cross-sectional study of HIV Gag-specific T cell function in HIV-1- and HIV-2-infected Gambians. Using cytokine flow cytometry and lymphoproliferation assays, we show that HIV-specific CD4+ T cells from HIV-2-infected individuals maintained proliferative capacity, were not terminally differentiated (CD57-), and more frequently produced IFN-gamma or IL-2 than CD4+ T cells from HIV-1-infected donors. Polyfunctional (IFN-gamma+/IL-2+) HIV-specific CD4+ T cells were found exclusively in HIV-2+ donors. The disparity in CD4+ T cell responses between asymptomatic HIV-1- and HIV-2-infected subjects was not associated with differences in the proliferative capacity of HIV-specific CD8+ T cells. This study demonstrates that HIV-2-infected donors have a well-preserved and
CD248 (endosialin) is a transmembrane glycoprotein that is dynamically expressed on pericytes and fibroblasts during tissue development, tumour neovascularization and inflammation. Its role in tissue remodelling is associated with increased stromal cell proliferation and migration. We show that CD248 is also uniquely expressed by human, but not mouse (C57BL/6), CD8(+) naive T cells. CD248 is found only on CD8(+) CCR7(+) CD11a(low) naive T cells and on CD8 single-positive T cells in the thymus. Transfection of the CD248 negative T-cell line MOLT-4 with CD248 cDNA surprisingly reduced cell proliferation. Knock-down of CD248 on naive CD8 T cells increased cell proliferation. These data demonstrate opposing functions for CD248 on haematopoietic (CD8(+)) versus stromal cells and suggests that CD248 helps to maintain naive CD8(+) human T cells in a quiescent state.
The primary goal of this study was to resolve the uncertainty about whether HESNs make T cell responses to HIV-1. We compared the frequencies of HIV-1-specific T cell responses over time between HESN and HUSN groups in a powered, blind study with independent data analysis. In these donors, no T cell responses were detectable without culture, except, notably, in an HESN participant who was homozygous for CCR5Δ32 and therefore genetically resistant to HIV-1 infection (18, 46). Using the more sensitive cultured ELISpot assay, T cell responses were found in both HESNs and HUSNs. Significant differences were found in the frequencies of T cell responses over time, with HESNs more likely to have positive T cell responses than HUSNs. HESNs more often maintained HIV-1-specific T cell responses across visits than HUSNs. Also, among positive responders, T cell responses were of significantly higher magnitude in HESNs than in HUSNs. Given that the cultured ELISpot assay expands antigen-specific cells ...
BACKGROUND: High levels of ex vivo CD4 T-cell death and the accumulation of highly differentiated and/or immunosenescent T cells have been associated with poor CD4 T-cell recovery in treated HIV-infected individuals. However, the relationship between cell death and T-cell differentiation is still unclear. METHODS: We have analyzed cell death, immunosenescence and differentiation parameters in HAART-treated subjects (VL |50 copies/mL for more than 2 years) with CD4 T-cell count |350 cells/μL (immunodiscordant, n = 23) or |400 cells/μL (immunoconcordant, n = 33). We included 11 healthy individuals as reference. RESULTS: As expected, suboptimal CD4 T-cell recovery was associated with low frequencies of naïve cells, high frequencies of transitional and effector memory cells and a subsequent low ratio of central/transitional memory cells in the CD4 compartment. These alterations correlated with spontaneous CD4 T-cell death. A deeper analysis of cell death in CD4 T-cell subsets showed increased cell death
BACKGROUND: The relative immunogenicity of human immunodeficiency virus type 1 (HIV-1) proteins for CD8+ and CD4+ cell responses has not been defined. METHODS: HIV-1-specific T cell responses were evaluated in 65 chronically HIV-1-infected untreated subjects by interferon- gamma flow cytometry with peptides spanning the clade C consensus sequence. RESULTS: The magnitude of HIV-1-specific CD8+ T cell responses correlated significantly with CD4+ cell responses, but the percentage of CD8+ T cells directed against HIV-1 (median, 2.76%) was always greater than that of CD4+ cells (median, 0.24%). Although CD8+ T cell responses were equally distributed among Gag, Pol, and the regulatory and accessory proteins, Gag was the dominant target for CD4+ cell responses. There was no consistent relationship between virus-specific CD8+ or CD4+ cell response and viral load. However, the median viral load in subjects in whom Gag was the dominant CD8+ T cell target was significantly lower than that in subjects in whom non
Methods and Results: High-purity sorted CD4+ T cells from ACS patients were treated with a panel of cytokines (TNF-α, IL-1β, IL-6, IL-7, IL-15), and effects on the number, phenotype and function of CD28null T cells were analysed and compared to the control counterpart CD28+ T cell subset. IL-7 and IL-15 induced expansion of CD28null T cells from ACS patients, while inflammatory cytokines TNF-α, IL-1β and IL-6 did not. The mechanisms underlying CD28null T cell expansion by IL-7/IL-15 were preferential activation and proliferation of CD28null T cells compared to control CD28+ T cells. Additionally, IL-7/IL-15 markedly augmented CD28null T cell cytotoxic function and interferon-γ production. Further mechanistic analyses revealed differences in baseline expression of component chains of IL-7/IL-15 receptors (CD127 and CD122) and increased baseline STAT5 phosphorylation in CD28null T cells from ACS patients compared to the control CD28+ T cell subset. Notably, we demonstrate that CD28null T cell ...
The mechanisms underlying the regulation of immune activation and immune exhaustion of T cells are unclear. Tregs have been investigated in HIV-1-infected subjects with conflicting results. Our data suggest that exhausted T cells are not only associated with hyperactivated T cells but also with reduced numbers of Tregs. When we determined the CD4+CD25bright FoxP3+ Treg population in proportion to CD4+CD25bright FoxP3 negative non-Treg activated CD4 T cells, we noted that the proportions were altered in favor of the non-Treg-activated CD4 T cells in HIV-positive subjects. In this analysis, however, the changes observed in Treg frequency could have simply been a consequence of changes in activated CD4+ T-cell frequency. On the other hand, the percentage of Tregs in the total CD4+ T-cell population of the viremic patients was also significantly lower as compared with aviremic patients and to healthy controls. As activated CD8 T cells were also clearly higher in viremic patients, this provides ...
Despite progress toward understanding the correlates of protective T cell immunity in HIV infection, the optimal approach to Ag delivery by vaccination remains uncertain. We characterized two immunodominant CD8 T cell populations generated in response to immunization of BALB/c mice with a replication-deficient adenovirus serotype 5 vector expressing the HIV-derived Gag and Pol proteins at equivalent levels. The Gag-AI9/H-2Kd epitope elicited high-avidity CD8 T cell populations with architecturally diverse clonotypic repertoires that displayed potent lytic activity in vivo. In contrast, the Pol-LI9/H-2Dd epitope elicited motif-constrained CD8 T cell repertoires that displayed lower levels of physical avidity and lytic activity despite equivalent measures of overall clonality. Although low-dose vaccination enhanced the functional profiles of both epitope-specific CD8 T cell populations, greater polyfunctionality was apparent within the Pol-LI9/H-2Dd specificity. Higher proportions of central ...
The initial idea that high amounts of cytopathic virus produced everyday can drive high CD4+ T cell production seemed logical and explained the progressive CD4+ T cell depletion observed in HIV-infected subjects. It was hypothesized that the CD4+ T lymphocyte production was increased up to 70-fold in HIV-infected subjects. Determination of the CD4+ T cell production was based on the kinetics of CD4+ T cell recovery following initiation of highly-active antiretroviral therapy (HAART). However, this analysis was limited by: (1) the assumption that blood CD4+ T cells are representative of the lymph node T cells; and (2) the lack of estimates of CD4+ T lymphocyte turnover in healthy HIV-negative subjects. Several immunologists have expressed caution regarding the assumptions used in modeling CD4+ T cell dynamics. Recent findings clearly show that blood is not representative of lymphoid tissues. Indeed, when blood and lymph node compartments are considered together, we find that HIV -infected ...
The peripheral naive T-cell pool is generally thought to consist of a subpopulation of recent thymic emigrants (RTE) and a subpopulation of mature naive (MN) T cells with different dynamics. Thymus transplantation and adoptive transfer studies in mice have provided contradicting results, with some studies suggesting that RTE are relatively short-lived cells, while another study suggested that RTE have a survival advantage. We here estimate the death rates of RTE and MN T cells by performing both thymus transplantations and deuterium labeling experiments in mice of at least 12 weeks old, an age at which the size of the T-cell pool has stabilized. For CD4+ T cells, we found the total loss rate from the RTE compartment (by death and maturation) to be 4-fold faster than that of MN T cells. We estimate the death rate of CD4+ RTE to be 0.046 per day, which is 3-fold faster than the total loss rate from the MN T-cell compartment. For CD8+ T cells, we found no evidence for kinetic differences between RTE and MN
Autoreactive CD8 T cells play a central role in the destruction of pancreatic islet β-cells that leads to type 1 diabetes, yet the key features of this immune-mediated process remain poorly defined. In this study, we combined high-definition polychromatic flow cytometry with ultrasensitive peptide-human leukocyte antigen class I tetramer staining to quantify and characterize β-cell-specific CD8 T cell populations in patients with recent-onset type 1 diabetes and healthy control subjects. Remarkably, we found that β-cell-specific CD8 T cell frequencies in peripheral blood were similar between subject groups. In contrast to healthy control subjects, however, patients with newly diagnosed type 1 diabetes displayed hallmarks of antigen-driven expansion uniquely within the β-cell-specific CD8 T cell compartment. Molecular analysis of selected β-cell-specific CD8 T cell populations further revealed highly skewed oligoclonal T cell receptor repertoires comprising exclusively private clonotypes. ...
TY - JOUR. T1 - Expression of the costimulatory receptor CD30 is regulated by both CD28 and cytokines. AU - Gilffillan, Molly C.. AU - Noel, Patricia J.. AU - Podack, Eckhard R.. AU - Reiner, Steven L.. AU - Thompson, Craig B.. PY - 1998/3/1. Y1 - 1998/3/1. N2 - Costimulation was originally defined and characterized during primary T cell activation. The signaling events that regulate subsequent antigen encounters by T cells are less well defined. In this study we examined the role of CD30 in T cell activation and defined factors that regulate expression of CD30 on T cells. We demonstrate that CD30 expression is restricted to activated T cells and regulated by CD28 signal transduction. In contrast to CD28-expressing TCR Tg cells, CD28-deficient TCR Tg cells did not express CD30 when cultured with peptide and APCs. However, rIL-4 reconstituted CD30 expression on CD28-deficient TCR Tg cells. Blockade of CD28 interactions or depletion of IL-4 inhibited the induction of CD30, suggesting that both ...
Interleukin-15 (IL-15) is an inflammatory cytokine whose role in autoimmune diseases has not been fully elucidated. Th17 cells have been shown to play critical roles in experimental autoimmune encephalomyelitis (EAE) models. In this study, we demonstrate that blockade of IL-15 signaling by TMβ-1 mAb treatment aggravated EAE severity. The key mechanism was not NK-cell depletion but depletion of CD8+ CD122+ T cells. Adoptive transfer of exogenous CD8+ CD122+ T cells to TMβ-1-treated mice rescued animals from severe disease. Moreover, transfer of pre-activated CD8+CD122+ T cells prevented EAE development and significantly reduced IL-17 secretion. Naïve effector CD4+ CD25- T cells cultured with either CD8+CD122+ T cells from wild-type mice or IL-15 transgenic mice displayed lower frequencies of IL-17A production with lower amounts of IL-17 in the supernatants when compared with production by effector CD4+ CD25- T cells cultured alone. Addition of a neutralizing antibody to IL-10 led to recovery ...
Hyperactivation of T cells, particularly of CD8(+) T cells, is a hallmark of chronic HIV 1 (HIV-1) infection. Little is known about the antigenic specificities and the mechanisms by which HIV-1 causes activation of CD8(+) T cells during chronic infection. We report that CD8(+) T cells were activated during in vivo HIV-1 replication irrespective of their Ag specificity. Cytokines present during untreated HIV-1 infection, most prominently IL-15, triggered proliferation and expression of activation markers in CD8(+) T cells, but not CD4(+) T cells, in the absence of TCR stimulation. Moreover, LPS or HIV-1-activated dendritic cells (DCs) stimulated CD8(+) T cells in an IL-15-dependent but Ag-independent manner, and IL-15 expression was highly increased in DCs isolated from viremic HIV-1 patients, suggesting that CD8(+) T cells are activated by inflammatory cytokines in untreated HIV-1 patients independent of Ag specificity. This finding contrasts with CD4(+) T cells whose in vivo activation seems ...
Interleukin-12 (IL-12) induces differentiation of T helper 1 (Th1) cells, primarily through its ability to prime T cells for high interferon-gamma (IFN-gamma) production. We now report that the presence of IL-12 during the first several days of in vitro clonal expansion in limiting dilution cultures of polyclonally stimulated human peripheral blood CD4+ and CD8+ T cells also induces stable priming for high IL-10 production. This effect was demonstrated with T cells from both healthy donors and HIV+ patients. Priming for IL-4 production, which requires IL-4, was maximum in cultures containing both IL-12 and IL-4. IL-4 modestly inhibited the IL-12-induced priming for IFN-gamma, but almost completely suppressed the priming for IL-10 production. A proportion of the clones generated from memory CD45RO+ cells, but not those generated from naive CD45RO- CD4+ T cells, produced some combinations of IFN-gamma, IL-10, and IL-4 even in the absence of IL-12 and IL-4, suggesting in vivo cytokine priming; ...
The function of CD8 cells in the human body is to kill infected target cells, such as HIV infected cells. Recent data suggest that intravenous administration of HIV-specific CD8 cells is safe, augments host immunity, and mediates a dramatic reduction in circulating HIV-infected CD4 cells. However, the observed antiviral effects are transient, and HIV infected CD4 cells re-emerge as the number of self CD8 cells declines. Augmenting CD8 cell response to HIV by immunotherapy with CD8 cells may be a useful addition to drug therapy if the infused CD8 cells can survive long-term in vivo. Administration of interleukin-2 (also known as aldesleukin or IL-2), a naturally occurring cytokine, has been proposed as a way to maintain the number of CD8 cells. This study will evaluate the safety and efficacy of immunotherapy with HIV-specific CD8 cells in HIV infected patients. Additionally, this study will determine if aldesleukin injections improve the persistence of self CD8 transplants and the duration of ...
The function of CD8 cells in the human body is to kill infected target cells, such as HIV infected cells. Recent data suggest that intravenous administration of HIV-specific CD8 cells is safe, augments host immunity, and mediates a dramatic reduction in circulating HIV-infected CD4 cells. However, the observed antiviral effects are transient, and HIV infected CD4 cells re-emerge as the number of self CD8 cells declines. Augmenting CD8 cell response to HIV by immunotherapy with CD8 cells may be a useful addition to drug therapy if the infused CD8 cells can survive long-term in vivo. Administration of interleukin-2 (also known as aldesleukin or IL-2), a naturally occurring cytokine, has been proposed as a way to maintain the number of CD8 cells. This study will evaluate the safety and efficacy of immunotherapy with HIV-specific CD8 cells in HIV infected patients. Additionally, this study will determine if aldesleukin injections improve the persistence of self CD8 transplants and the duration of ...
TY - JOUR. T1 - Counter-regulation of regulatory T cells by autoreactive CD8 + T cells in rheumatoid arthritis. AU - Cammarata, Ilenia. AU - Martire, Carmela. AU - Citro, Alessandra. AU - Raimondo, Domenico. AU - Fruci, Doriana. AU - Melaiu, Ombretta. AU - DOria, Valentina. AU - Carone, Chiara. AU - Peruzzi, Giovanna. AU - Cerboni, Cristina. AU - Santoni, Angela. AU - Sidney, John. AU - Sette, Alessandro. AU - Paroli, Marino. AU - Caccavale, Rosalba. AU - Milanetti, Edoardo. AU - Riminucci, Mara. AU - Timperi, Eleonora. AU - Piconese, Silvia. AU - Manzo, Antonio. AU - Montecucco, Carlomaurizio. AU - Scrivo, Rossana. AU - Valesini, Guido. AU - Cariani, Elisabetta. AU - Barnaba, Vincenzo. PY - 2019/1/1. Y1 - 2019/1/1. N2 - The mechanisms whereby autoreactive T cells escape peripheral tolerance establishing thus autoimmune diseases in humans remain an unresolved question. Here, we demonstrate that autoreactive polyfunctional CD8 + T cells recognizing self-antigens (i.e., vimentin, actin ...
CD8hiCD57+ T cells have previously been described as effector memory T cells with minimal expansion capacity and high susceptibility to activation-induced cell death. In contrast, we demonstrate here that CD8hiCD57+ T cells are capable of rapid expansion using multiple techniques including [3H]thymidine uptake, flow cytometric bead-based enumeration and standard haemocytometer counting. Previous reports can be explained by marked inhibition of activation-induced expansion and increased 7-amino-actinomycin D uptake by CD8hiCD57+ T cells following treatment with CFSE, a dye previously used to measure their proliferation, combined with specific media requirements for the growth of this cell subset. The ability of CD8hiCD57+ T cells to further differentiate is highlighted by a distinct cytokine profile late after activation that includes the unexpected release of high levels of interleukin 5. These data indicate that CD8hiCD57+ T cells should not be considered as end-stage effector T cells ...
TY - JOUR. T1 - Failure to suppress the expansion of the activated CD4 T cell population in interferon γ-deficient mice leads to exacerbation of experimental autoimnaune encephalomyelitis. AU - Chu, Cong Qiu. AU - Wittmer, Susan. AU - Dalton, Dyana K.. PY - 2000/7/3. Y1 - 2000/7/3. N2 - Mice deficient in interferon (IFN)-γ or IFN-γ receptor develop progressive and fatal experimental autoimmune encephalomyelitis (EAE). We demonstrate that CD4 T cells lacking IFN-γ production were required to passively transfer EAE, indicating that they were disease-mediating cells in IFN-γ knockout (KO) mice. IFN-γ KO mice accumulated 10-16-fold more activated CD4 T cells (CD4+CD44(hi)) than wild-type mice in the central nervous system during EAE. CD4+CD44(hi) T cells in the spleen and central nervous system of IFN-γ KO mice during EAE showed markedly increased in vivo proliferation and significantly decreased ex vivo apoptosis compared with those of wild-type mice. IFN-ψ KO CD4+CD44(hi) T cells ...
The occurrence of massive CD4+ T cell depletion is one of the most prominent characteristics of human immunodeficiency virus type 1 (HIV-1) infection during acute phase, resulting in unrestorable destruction to the immune system. The infected host undergoes an asymptomatic period lasting several years with low viral load and ostensibly healthy status, which is presumably due to virus-specific adaptive immune responses. In the absence of therapy, an overwhelming majority of cases develop to AIDS within 8-10 years of latent infection. In this review, we discuss the roles in AIDS pathogenesis played by massive CD4+ T lymphocytes depletion in gut-associated lymphoid tissue (GALT) during acute infection and abnormal immune activation emerging in the later part of chronic phase.
Fingerprint Dive into the research topics of Recognition of naturally processed and ovarian cancer reactive CD8 ,sup,+,/sup, T cell epitopes within a promiscuous HLA class II T-helper region of NY-ESO-1. Together they form a unique fingerprint. ...
In the absence of foreign antigen, peripheral naive T cells continuously recirculate between different lymphoid organs, in which they interact frequently and shortly with self. We and others have shown that such interactions are required for the long-term survival of naïve T cells. In addition, these TCR/MHC interactions and the resulting associated signaling increase quantitatively T-cell responsiveness towards foreign antigens and influence their function and/or differentiation into effector or memory cells in response to stimulation. Our project is based on our recent data showing that peripheral ab and gd T cells can be subdivided into various subsets according to Ly-6C expression. Interestingly, in CD4 ab T cells, Ly-6C expression inversely correlates with the ability of these cells to interact with self, defining Ly-6C as a new sensor of T cell self-reactivity. In parallel, we are exploring the regulation of T-cell self-reactivity in the context of cancer. Indeed, T cells specific for ...
Zhang Y, Feng ZP, Naselli G, Bell F, Wettenhall J, Auyeung P, Ellis JA, Ponsonby AL, Speed TP, Chong MM, Harrison LC. MicroRNAs in CD4(+) T cell subsets are markers of disease risk and T cell dysfunction in individuals at risk for type 1 diabetes. Journal of autoimmunity 68 : 52 - 61(2016) PubMed (Grant IDs: 637338, 1004541, 1037321, 1026349 ...
The origin of CD4+ T cells reappearing in the blood following antiretroviral therapy in human immunodeficiency virus type-1 (HIV-1) infection is still controversial. Here we show, using mathematical modeling, that redistribution of T cells to the blood can explain the striking correlation between the initial CD4+ and CD8+ memory T-cell ... read more repopulation and the observation that 3 weeks after the start of treatment memory CD4+ T-cell numbers reach a plateau. The increase in CD4+ T cells following therapy most likely is a composite of initial redistribution, accompanied by a continuous slow repopulation with newly produced naive T cells. show less ...
Multiple viral and host factors determine the variability in HIV-1 disease progression [17, 23-26]. Cellular tropism and receptor/co-receptor usage for viral entry are major factors influencing HIV pathogenesis. Despite extensive research, the exact mechanism of how those factors contribute to the gradual loss of CD4 T cells is still enigmatic. Bystander CD4 T cell death plays a major contribution towards AIDS progression. A recent report has revealed a mechanism for HIV-induced CD4 T cell depletion, which involves abortive non-productive HIV infection in resting CD4 T cells, followed by IFI16 activation and caspase-1 dependent pyroptosis [27-29]. Besides the abortive RT products in non-productively infected resting cells, several HIV-1 proteins have also been reported to contribute to the depletion of bystander (uninfected and non-productively infected) CD4 T cells, including the Env [4, 5, 17, 19], Vpr [30], Nef [31, 32] and Tat [33]. The Env protein is of specific interest in mediating AIDS ...
T cell responses play an important role in the outcome of HBV and HCV infection, e.g. viral elimination versus persistence. However, multiple mechanisms can lead to the failure of the virus-specific T cell response. These mechanisms include primary T cell failure, T cell exhaustion, the emergence of viral escape mutants, as well as T cell dysfunction. Furthermore, genetic factors such as the individual HLA allele background play an important role in the outcome of infection. Once viral persistence has been established, HBV or HCV infection can progress to liver fibrosis and cirrhosis with an enhanced risk for HCC. Tumor-specific T cells (e.g. AFP-specific T cells) are thought to contribute to cancer control.. The focus of our group is the identification and characterization of virus-specific CD4+ and CD8+ T cell responses during acute and chronic HBV and HCV infection with a special focus on intrahepatic T cell responses as well as the mechanisms of viral persistence (e.g., viral escape, T cell ...
In this study, we documented that local cryo-thermal therapy generated a stronger systematic antitumor immune response than RFA and a long-lasting antitumor immunity that protected against tumor rechallenge. At the same time, a systemic antigen-specific T-cell immune response induced via local cryo-thermal therapy was revealed. Although the survival rate between RFA and cryo-thermal therapy was not statistically significant, the long-term immunity against tumor challenge elicited by two treatments was different. In vitro studies showed that the antigen-specific CD8+ T-cell response was induced by both cryo-thermal therapy and RFA, but the strong neoantigen-specific CD4+ T-cell response was only induced by cryo-thermal therapy. Moreover, we demonstrated that the cryo-thermal therapy-induced strong antitumor immune response was mainly mediated by CD4+ T-cells, particularly neoantigen-specific CD4+ T-cells, which are the major contributors to the cryo-thermal therapy-induced antitumor immune ...
TY - JOUR. T1 - Comparable T helper 1 (Th1) and CD8 T-cell immunity by targeting HIV gag p24 to CD8 dendritic cells within antibodies to Langerin, DEC205, and Clec9A. AU - Idoyaga, Juliana. AU - Lubkin, Ashira. AU - Fiorese, Christopher. AU - Lahoud, Mireille H.. AU - Caminschi, Irina. AU - Huang, Yaoxing. AU - Rodriguez, Anthony. AU - Clausen, Björn E.. AU - Park, Chae Gyu. AU - Trumpfheller, Christine. AU - Steinmana, Ralph M.. PY - 2011/2/8. Y1 - 2011/2/8. N2 - Improved protein-based vaccines should facilitate the goal of effective vaccines against HIV and other pathogens. With respect to T cells, the efficiency of immunization, or immunogenicity, is improved by targeting vaccine proteins to maturing dendritic cells (DCs) within mAbs to DC receptors. Here, we compared the capacity of Langerin/CD207, DEC205/CD205, and Clec9A receptors, each expressed on the CD8+ DC subset in mice, to bring about immunization of microbial-specific T cells from the polyclonal repertoire, using HIV gag-p24 ...
Microbiota-reactive CD4+ T memory (TM) cells are generated during intestinal infections and inflammation, and can revert to pathogenic CD4+ T effector (TE) cells, resulting in chronicity of inflammatory bowel disease (IBD). Unlike TE cells, TM cells have a low rate of metabolism unless they are activated by reencountering cognate antigen. Here, we show that the combination of cell activation and metabolic checkpoint inhibition (CAMCI), by targeting key metabolic regulators mTORC and AMPK, resulted in cell death and anergy, but enhanced the induction of the regulatory subset. Parenteral application of this treatment with a synthetic peptide containing multiple flagellin T cell epitopes (MEP1) and metabolic inhibition successfully prevented the development of CD4+ T cell-driven colitis. Microbiota-specific CD4+ T cells, especially the pathogenic TE subsets, were decreased 10-fold in the intestinal lamina propria. Furthermore, using the CAMCI strategy, we were able to prevent antigen-specific TM ...
In the present study, we demonstrate a novel mechanism by which CD8+ T cells contribute to atherogenesis through modulation of medullar monopoiesis and circulating Ly6Chi monocyte levels, thereby indirectly controlling macrophage accumulation within lesions.. Previous studies addressing the role of CD8+ T cells in atherogenesis have mostly used genetically engineered mouse models of CD8+ T-cell deficiency with contradictory results,17,18 which may be because of compensatory mechanisms in these mice. We circumvented this hurdle by treating Ldlr−/− mice with an anti-CD8α monoclonal antibody, which efficiently depleted CD8+ T cells while not altering DCs levels, including CD8α+ DCs, and functionality of splenic CD11c+ DCs, as well as leaving CD4+ T cell numbers, activation and polarization untouched, thus confirming the specificity of our depletion strategy.. CD8+ T-cell depletion with the anti-CD8α antibody entailed a significant decrease in atherosclerotic lesion formation in the aortic ...
The human brain is an important site of HIV replication and persistence during antiretroviral therapy (ART). Direct evaluation of HIV infection in the brains of otherwise healthy individuals is not feasible; therefore, we performed a large-scale study of bone marrow/liver/thymus (BLT) humanized mice as an in vivo model to study HIV infection in the brain. Human immune cells, including CD4+ T cells and macrophages, were present throughout the BLT mouse brain. HIV DNA, HIV RNA, and/or p24+ cells were observed in the brains of HIV-infected animals, regardless of the HIV isolate used. HIV infection resulted in decreased numbers of CD4+ T cells, increased numbers of CD8+ T cells, and a decreased CD4+/CD8+ T cell ratio in the brain. Using humanized T cell-only mice (ToM), we demonstrated that T cells establish and maintain HIV infection of the brain in the complete absence of human myeloid cells. HIV infection of ToM resulted in CD4+ T cell depletion and a reduced CD4+/CD8+ T cell ratio. ART ...
The human brain is an important site of HIV replication and persistence during antiretroviral therapy (ART). Direct evaluation of HIV infection in the brains of otherwise healthy individuals is not feasible; therefore, we performed a large-scale study of bone marrow/liver/thymus (BLT) humanized mice as an in vivo model to study HIV infection in the brain. Human immune cells, including CD4+ T cells and macrophages, were present throughout the BLT mouse brain. HIV DNA, HIV RNA, and/or p24+ cells were observed in the brains of HIV-infected animals, regardless of the HIV isolate used. HIV infection resulted in decreased numbers of CD4+ T cells, increased numbers of CD8+ T cells, and a decreased CD4+/CD8+ T cell ratio in the brain. Using humanized T cell-only mice (ToM), we demonstrated that T cells establish and maintain HIV infection of the brain in the complete absence of human myeloid cells. HIV infection of ToM resulted in CD4+ T cell depletion and a reduced CD4+/CD8+ T cell ratio. ART ...
Many T lymphocytes were identified by these authors positive to CD4 and CD8. Macrophages and T lymphocytes demonstrated a ... The foam cells of monocyte/macrophage origin are positive for KP1, HAM56, CD11b and CD68 as pointed out by Nakashiro et al. in ... Under microscope, the cellular infiltrate includes neutrophils, lymphocytes, plasma cells, erythrocytes, hemosiderin-laden ...
A few TCR variants that recognize these DQ/antigen complexes are on CD4 positive T-cells. These T-cells, called T-helper (Th) ... Alternatively, macrophages and other cytotoxic lymphocytes consume or destroy cells by apoptotic signaling and present self- ... and B-lymphocytes). Normally, these APC 'present' class II receptor/antigens to a great many T-cells, each with unique T-cell ...
During the chronic phase, a high amount of CD4 T- cells and a few IgM-positive B-cells were observed. Infections of chickens ... The most activity was observed during the subacute phase with an increase in CD8 and CD4 lymphocytes. At this phase, clusters ... Within the synovium collected, plasma cells and T-lymphocytes were the primary inflammatory cells present. During the acute- ... and T and B-lymphocytes were observed to determine its effects on cellular infiltrates during the development of reovirus ...
A few TCR variants that recognize these DQ/antigen complexes are on CD4 positive (CD4+) T-cells. These T-cells, called T-helper ... and B-lymphocytes). Normally, these APC 'present' class II receptor/antigens to a great many T-cells, each with unique T-cell ... Regional Evolution Many HLA DQ were under positive selection of 10,000s potentially 100,000s of years in some regions. As ... of celiac disease patients are positive for DQ2 or DQ8. Rubio García, Arcadio; Paterou, Athina; Lee, Mercede; Sławiński, Hubert ...
This method is useful for isolation of a particular cell type, for instance CD4 lymphocytes. With negative selection, the ... With positive selection, the cells expressing the antigen(s) of interest, which attached to the magnetic column, are washed out ...
He is best known for his work regarding lymphocyte development, particularly the differentiation of immature CD4+8+ (double ... positive) thymocytes into mature T cells. Singer's work is foundational in the understanding of T cells and MHC-restricted ... SInger A, Adoro S, Park JH: Lineage fate and intense debate: myths, models and mechanisms of CD4- versus CD8-lineage choice. ... models and mechanisms of CD4- versus CD8-lineage choice". Nature Reviews Immunology. 8 (10): 788-801. doi:10.1038/nri2416. ISSN ...
... principally the CD4+ T-helper lymphocytes. As well as lymphocytes, CD4 receptors are also present on the surface of macrophages ... Patients who are infected with human immunodeficiency virus positive have an increased risk of developing infections and ... The lower the CD4 count, the greater the likelihood and the severity of illness. A CD4 count less than 200 is a diagnosis of ... The normal CD4 count is 500-1500 per mm3, and patients with human immunodeficiency virus infection often have a CD4 count less ...
... specifically decreased CD8-positive T cell and NK cell numbers and an increase in CD4-positive T cells. The mice also had an ... Homozygous mutant animals had abnormal peripheral blood lymphocytes, ...
... positive for both CD4 and CD8). The final stage in maturation is the single positive stage (positive for either CD4 or CD8). In ... Additionally, other non-T hematopoietic lineages can develop in the thymus, including B lymphocytes (B cells), Natural Killer ... At this stage thymocytes upregulate both CD4 and CD8, becoming double positive cells. Double positive thymocytes that have a T ... Expression of both CD4 and CD8 makes them double positive, and matures into either CD4+ or CD8+ cells. Thymocytes are ...
CD8 positive T cell; a T cell receptor that binds mostly to MHC class II tends to produce a CD4 positive T cell. T cells that ... B cells and T cells were identified as different types of lymphocytes in 1968, and the fact that T cells required maturation in ... Some CD4 positive T cells exposed to self antigens persist as T regulatory cells. As the thymus is where T cells develop, ... The subtypes of T cells (CD8 and CD4) were identified by 1975. The way that these subclasses of T cells matured - positive ...
CD4+CD8+ double-positive thymocytes surrounded by specially differentiated cTECs called thymic nurse cells are tested for ... CD83 expression correlates with rate of activation of B lymphocytes and it is under control of the B cell receptor, CD40, or ... Upregulation of MHC II turnover on thymic nurse cells by CD83 may enlarge the population of CD4+ single-positive thymocytes. T ... A MARCH1 knockout mouse shows accumulation of MHC II, which leads to reduced CD4+ T lymphocyte activation and reduced IL-12 ...
In humans, cognitive stimulation increases circulating CD4-positive T lymphocytes, supporting the idea that immunity can be ... Other published research explored differences between the cerebral cortex of male and female rats, the link between positive ... voluntarily modulated, in other words, that positive thinking can impact the immune system. Mohammed, A. H., Zhu, S. W., ...
... has been found to be involved in the breaking of bonds on the HIV gp120 protein during HIV infection of CD4 positive cells, and ... is required for HIV infection of lymphocytes and monocytes. Some studies have shown it to be available for HIV infection on the ... surface of the cell clustered around the CD4 protein. Yet conflicting studies have shown that it is not available on the cell ...
... are proliferated and differentiated to the double positive (DP) stages. These CD4+ and CD8+ double positive T lymphocytes ... Double negative (DN) T cells, as a progenitors with CD44 and CD25 expression but lack of CD4 and CD8 coreceptor expression, ... T lymphocytes. These single positive cells migrate out of the cortex to the medulla, where the process continues as a negative ... These factors partake in positive selection of T cells. Specific markers on the surface of cTEC are Ly51 and CD 205 and even ...
... cd4-positive t-lymphocytes MeSH A11.118.637.555.567.569.200.400 - t-lymphocytes, helper-inducer MeSH A11.118.637.555.567.569. ... cd8-positive t-lymphocytes MeSH A11.118.637.555.567.569.220.200 - t-lymphocytes, cytotoxic MeSH A11.118.637.555.567.569.500 - t ... b-lymphocyte subsets MeSH A11.118.637.555.567.550.500 - t-lymphocyte subsets MeSH A11.118.637.555.567.562 - b-lymphocytes MeSH ... lymphocyte subsets MeSH A11.118.637.555.567.622 - lymphocytes, null MeSH A11.118.637.555.567.650 - lymphocytes, tumor- ...
... t-lymphocytes MeSH A15.145.229.637.555.567.569.200 - cd4-positive t-lymphocytes MeSH A15.145.229.637.555.567.569.200.400 - t- ... cd4-positive t-lymphocytes MeSH A15.382.490.555.567.569.200.400 - t-lymphocytes, helper-inducer MeSH A15.382.490.555.567.569. ... cd8-positive t-lymphocytes MeSH A15.145.229.637.555.567.569.220.200 - t-lymphocytes, cytotoxic MeSH A15.145.229.637.555.567. ... t-lymphocytes, regulatory MeSH A15.382.490.555.567.569.220 - cd8-positive t-lymphocytes MeSH A15.382.490.555.567.569.220.200 - ...
... or CD8-positive lymphocytes and IgG4-positive plasma cells, and exhibits interstitial fibrosis and acinar cell atrophy in later ... Histopathologic examination of the pancreas reveals a characteristic lymphoplasmacytic infiltrate of CD4- ... It has been proposed that a cytologic smear primarily composed of acini rich in chronic inflammatory cells (lymphocytes, plasma ... Histopathologic examination of the pancreas shows fibrotic changes with lymphocyte and plasma cell infiltrate. For diagnosis, ...
Foreign antigens presented by MHC class I attract T-lymphocytes called killer T-cells (also referred to as CD8-positive or ... These particular antigens stimulate the multiplication of T-helper cells (also called CD4-positive T cells), which in turn ... HLAs corresponding to MHC class II (DP, DM, DO, DQ, and DR) present antigens from outside of the cell to T-lymphocytes. ... A representative cellular assay is the mixed lymphocyte culture (MLC) and used to determine the HLA class II types. The ...
... patients with a longer history of chronic HIV and higher CD4 nadir loss present with greater cerebral atrophy. CD4 lymphocyte ... A recent longitudinal study of a small representative cohort of HIV-positive patients on stable medication regiments suggests ... February 2010). "Effects of nadir CD4 count and duration of human immunodeficiency virus infection on brain volumes in the ... The severity of neurocognitive impairment is associated with nadir CD4, suggesting that earlier treatment to prevent ...
... increased numbers of CD4 negative, CD7 positive T cells, CD3 negative, CD4 positive T cells, or CD3 positive, CD4 negative, CD8 ... In on study of 16 lymphocyte-variant hypereosinophilia patients with the aberrant CD3 negative, CD41 positive immunophenotype, ... in T-cells or the proliferation of lymphocytes with the CD3 negative, CD41 positive immunophenotype may occur during the ... Lymphocyte-variant hypereosinophilia is a disorder attributed to the expansion of a cytokine-producing, aberrant population of ...
... and different lymphocyte subtypes, reacting to CD3, CD4, CD8, CD20 and CD138. The sensitivity of McDonald criteria is low with ... In order to reduce false positives, McDonald et al. propose that their criteria should be applied only after any other disease ... of positives in the follow up using as reference the 2010 criteria after a follow-up of 3.8 ± 2.9 years. No reduction in ... ", "dissemination" and a "positive MRI", etc. Later they were revised again in 2017. McDonald criteria are the standard ...
... epidermotropic cytotoxic T-cell lymphoma Primary cutaneous acral CD8-positive T-cell lymphoma Primary cutaneous CD4-positive ... Nodular lymphocyte predominant Hodgkin lymphoma Classic Hodgkin lymphoma Nodular sclerosis classic Hodgkin lymphoma Lymphocyte- ... leg type EBV-positive DLBCL, NOS EBV-positive mucocutaneous ulcer DLBCL associated with chronic inflammation Fibrin-associated ... ALK-positive Anaplastic large cell lymphoma, ALK-negative Breast implant-associated anaplastic large cell lymphoma Hodgkin ...
The increased VISTA levels correlated with an increase in immune activation and a decrease in CD4-positive T cells. There is an ... VISTA is produced at high levels in tumor-infiltrating lymphocytes, such as myeloid-derived suppressor cells and regulatory T ... "Coinhibitory receptor PD-1H preferentially suppresses CD4⁺ T cell-mediated immunity". Journal of Clinical Investigation. 124 (5 ...
T-PLL has the immunophenotype of a mature (post-thymic) T-lymphocyte, and the neoplastic cells are typically positive for pan-T ... The immunophenotype CD4+/CD8- is present in 60% of cases, the CD4+/CD8+ immunophenotype is present in 25%, and the CD4-/CD8+ ... A high lymphocyte count (> 100 x 109/L) along with low amounts of red blood cells and platelets in the blood are common ... In the peripheral blood, T-PLL consists of medium-sized lymphocytes with single nucleoli and basophilic cytoplasm with ...
1991). "Interaction of CD4 with HLA class II antigens and HIV gp120". Immunogenetics. 34 (2): 121-8. doi:10.1007/BF00211424. ... 1991). "Positive correlation between oligonucleotide typing and T-cell recognition of HLA-DP molecules". Immunogenetics. 34 (1 ... Class II molecules are expressed in antigen presenting cells (APC: B lymphocytes, dendritic cells, macrophages). The beta chain ... Clayton LK, Sieh M, Pious DA, Reinherz EL (1989). "Identification of human CD4 residues affecting class II MHC versus HIV-1 ...
... of cases Lymphocyte-rich Lymphocyte depleted or not depleted Nodular lymphocyte-predominant Hodgkin lymphoma Immunodeficiency- ... Negative interim PET scan results probably result in a large increase in the overall survival compared to those with a positive ... creating Pautrier microabscesseses CD4 5-year survival 75% Localized or more generalized skin symptoms, generally indolent, in ... Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the ...
Also, almost 90% of all thymocytes extracted from the female TNCs were found to be double positives (CD4+CD8+), whereas no such ... Penninger J, Hála K, Wick G. "Inrathymic nurse cell lymphocytes can induce a specific graft-versus-host reaction." J Exp Med ... found in their study that one-fourth of the nurse cells isolated from mice were double-positives for K5 and K8, while the rest ... Only intermediate affinity interaction between the αβTCR of the T cells and MHC antigens in the TNCs results in positive ...
... "double-positive" (DP) T cells (CD4+CD8+). The double-positive T cells are exposed to a wide variety of self-antigens in the ... Then, T-lymphocytes become memory T cells. This type of T cells are those that have been in contact with the antigen at least ... Those cells that survive positive and negative selection differentiate into single-positive T cells (either CD4+ or CD8+), ... MHC2 for CD4). In this case, the cells would have been presented antigen in the context of MHC1. Positive selection means ...
Nature 338, 591 (1989). Essential role of T cell receptor-mediated positive selection in T cell survival and lineage fate (CD4/ ... Von Boehmer studied the role of T lymphocytes in the immune system. In particular he addressed the contribution of the T cell ... Harald von Boehmer (30 November 1942 - 24 June 2018) was a German-Swiss immunologist best known for his work on T lymphocytes. ... Questions concerned with the role of positive and negative selection of developing T cells by peptide-MHC complexes in the ...
The risk of MAC is inversely related to the patient's CD4 count and increases significantly when the CD4 count decreases below ... Some age adjustment is necessary when clinicians interpret CD4+ T-lymphocyte counts in children less than 2 years of age. ... lavage culture demonstrating the infection is caused by MAC Disseminated MAC is most readily diagnosed by one positive blood ... People with HIV infection and less than 50 CD4 cells/uL should be administered prophylaxis against MAC. Prophylaxis should be ...
The molecule's positive charge allows for binding to phospholipids and cardiolipin, both of which can be found as epitopes on ... Donlon TA, Krensky AM, Clayberger C (1990). "Localization of the human T lymphocyte activation gene 519 (D2S69E) to chromosome ... "CD8 T cell-mediated killing of Cryptococcus neoformans requires granulysin and is dependent on CD4 T cells and IL-15". Journal ... Granulysin plays a role in a myriad of diseases, where it can be a positive or negative influence on the immune response. In ...
Excessive iron inhibits the activity of CD4 lymphocytes and suppresses the tumoricidal activity of macrophages. The third way ... Potassium absorption has a positive correlation with aquaporins and the uptake of water in plant cells via cell membrane ...
Doitsh G, Greene WC (March 2016). "Dissecting How CD4 T Cells Are Lost During HIV Infection". Cell Host & Microbe. 19 (3): 280- ... Kaposi's sarcoma, a virally-associated cancer, has higher incidence rates in HIV-positive patients than in the general ... caused by feline leukemia virus and feline immunodeficiency virus retroviral infections can be treated with lymphocyte T-cell ... A patient's risk level for developing an opportunistic infection is approximated using the patient's CD4 T-cell count and ...
The finding of the Pup/UBact-proteasome system in both gram-positive and gram-negative bacteria suggests that either the Pup/ ... Magadán JG, Pérez-Victoria FJ, Sougrat R, Ye Y, Strebel K, Bonifacino JS (April 2010). "Multilayered mechanism of CD4 ... "Isolation of a polypeptide that has lymphocyte-differentiating properties and is probably represented universally in living ... Prokaryotic ubiquitin-like protein (Pup) is a functional analog of ubiquitin which has been found in the gram-positive ...
For example, patients with tumors have a local relative excess of Foxp3 positive T cells which inhibits the body's ability to ... Zhang L, Zhao Y (June 2007). "The regulation of Foxp3 expression in regulatory CD4(+)CD25(+)T cells: multiple pathways on the ... These mice have overproliferation of CD4+ T-lymphocytes, extensive multiorgan infiltration, and elevation of numerous cytokines ... The induction or administration of Foxp3 positive T cells has, in animal studies, led to marked reductions in (autoimmune) ...
1991). "Interaction of CD4 with HLA class II antigens and HIV gp120". Immunogenetics. 34 (2): 121-8. doi:10.1007/BF00211424. ... Class II molecules are expressed in antigen-presenting cells (APC: B lymphocytes, dendritic cells, macrophages). The alpha ... 1987). "Allelic forms of the alpha- and beta-chain genes encoding DQw1-positive heterodimers". Immunogenetics. 26 (4-5): 282-90 ... Clayton LK, Sieh M, Pious DA, Reinherz EL (1989). "Identification of human CD4 residues affecting class II MHC versus HIV-1 ...
In T lymphocytes the expression of CCL7 occurs after 3-5 days after the stimulation. CCL7 has been shown to interact with MMP2 ... The positive effect of CCL7 is mainly observed in monocyte mobilization from bone marrow to blood circulation and in the ... October 1998). "HIV-1 envelope gp120 inhibits the monocyte response to chemokines through CD4 signal-dependent chemokine ... Song A, Nikolcheva T, Krensky AM (October 2000). "Transcriptional regulation of RANTES expression in T lymphocytes". ...
PRO 140 binds to the CCR5 receptor on the CD4 cells, and interferes with HIV's ability to enter the cell. PRO 140, a humanized ... Leronlimab (codenamed PRO 140) is a humanized monoclonal antibody targeted against the CCR5 receptor found on T lymphocytes of ... In November, the company reported positive results.[medical citation needed] On December 15, 2020, CytoDyn reached full ... The gp120 will bind CD4 and the CCR5co receptor molecule, and this triggers gp41-mediated fusion of the viral and cellular ...
Trichostatin Positive responses were observed in animal trials utilizing this HDAC inhibitor, associated with mediation of ... Another effect of VPA is its prevention of macrophage and lymphocyte proliferation in the spinal cords of MS rats. Currently, ... Higher expression of miR-155 and miR-326 is often associated with CD4+T cell differentiation, and with this differentiation, ... Valpropic Acid Valpropic acid has been shown to have positive results in animal trials, in the mitigation of the disease by ...
To prove this, several hundred experimental repopulation kinetics from clonal Thy-1lo SCA-1+ lin−(B220, CD4, CD8, Gr-1, Mac-1 ... In shape, hematopoietic stem cells resemble lymphocytes. The very first hematopoietic stem cells during (mouse and human) ... Lack of expression of lineage markers is used in combination with detection of several positive cell-surface markers to isolate ... Colony-forming unit-lymphocyte (CFU-L) Colony-forming unit-erythrocyte (CFU-E) Colony-forming unit-granulocyte-macrophage (CFU- ...
"CD4" and "CCR5". Attempts to interfere with the binding of HIV with the CD4 receptor have failed to stop HIV from infecting ... HIV most heavily targets a specific type of lymphocyte known as "helper T cells", and identifies these target cells through T- ... "Sexual Activity Without Condoms and Risk of HIV Transmission in Serodifferent Couples When the HIV-Positive Partner Is Using ... CD4 and a chemokine receptor (differing depending on the cell type). Approaches to blocking this virus/cell fusion have shown ...
This therapy showed positive results in its potential to be used as a method to enhance drug transport across the BBB. 2012 ... She began studying HIV during her postdoc, specifically exploring the CD4+ T-lymphocyte levels in patients with AIDS as well as ... Role of CD4 and Chemokine Receptors". AIDS Research and Human Retroviruses. 18 (8): 557-65. doi:10.1089/088922202753747905. ... in serologically positive but aparasitaemic sleeping-sickness suspects in Cameroon, by PCR". Annals of Tropical Medicine and ...
Vremec D, Pooley J, Hochrein H, Wu L, Shortman K (March 2000). "CD4 and CD8 expression by dendritic cell subtypes in mouse ... Removal of sialic acid residues from the surface of tumor cells makes them available to NK cells and cytotoxic T lymphocytes ... Natural high genomic stability of SeV is a positive feature for it potential use as a vaccine vector or as an oncolytic agent. ... SeV activates natural killer cells (NK), cytotoxic T lymphocytes (CTL) and dendritic cells (DC). The secretion of interleukin-6 ...
... s, also known as NK cells or large granular lymphocytes (LGL), are a type of cytotoxic lymphocyte critical ... NK cells apparently evolved as an evolutionary response to this adaptation (the loss of the MHC eliminates CD4/CD8 action, so ... CD56dim NK cells are always CD16 positive (CD16 is the key mediator of antibody-dependent cellular cytotoxicity (ADCC). ... Pross HF, Jondal M (August 1975). "Cytotoxic lymphocytes from normal donors. A functional marker of human non-T lymphocytes". ...
... provides a positive control when studying immune-response of a new drug. "cyclophosphamide - definition of ... Suggested mechanisms include: Elimination of T regulatory cells (CD4+CD25+ T cells) in naive and tumor-bearing hosts Induction ... "Immunosuppressive effect of cyclophosphamide on white blood cells and lymphocyte subpopulations from peripheral blood of Balb/c ...
... hemizygous mutant males had decreased CD4-positive and CD8-positive T cell numbers. RBBP7 has been shown to interact with: ... ". "Peripheral blood lymphocytes data for Rbbp7". Wellcome Trust Sanger Institute.[dead link] Gerdin AK (2010). "The Sanger ...
It was tested in France in a double-blind Phase I/II trial with 48 HIV-positive patients who had reached viral suppression on ... HVTN 703 and HVTN 704 found that the VRC01 monoclonal antibody, which targets the CD4 binding site, was not able to prevent HIV ... Watkins DI (March 2008). "The hope for an HIV vaccine based on induction of CD8+ T lymphocytes--a review". Memórias do ... Vrisekoop N, Mandl JN, Germain RN (2009). "Life and death as a T lymphocyte: from immune protection to HIV pathogenesis". ...
National Institutes of Health guidelines recommend treatment of any HIV-positive individuals, regardless of CD4 count Normal ... "Laboratory control values for CD4 and CD8 T lymphocytes. Implications for HIV-1 diagnosis". Clinical and Experimental ... A CD4 count measures the number of T cells expressing CD4. While CD4 counts are not a direct HIV test-e.g. they do not check ... before being named CD4 in 1984. In humans, the CD4 protein is encoded by the CD4 gene. CD4+ T helper cells are white blood ...
The incidence rises as the CD4 count falls, and the appearance of OHL may signify progression of HIV to AIDS. A study from 2001 ... When clinical appearance alone is used to diagnose OHL, there is a false positive rate of 17% compared to more objective ... from the immune system by latent infection of B lymphocytes. The virus also causes lytic infection in the oropharynx, but is ... Jung, AC; Paauw, DS (February 1998). "Diagnosing HIV-related disease: using the CD4 count as a guide". Journal of General ...
CD8+ T lymphocytes destroy melanocytes in some parts of the skin what manifest like white spots on the skin. Multiple genes as ... TRM cells positive for this marker produce perforin and IFNɤ. On the other side, TRM without CD49a expression produce IL-17. ... Tissue-retentive lung memory CD4 T cells mediate optimal protection to respiratory virus infection". Journal of Immunology. 187 ... Cytotoxic CD8+ T lymphocytes are able to recognize malignant cells. Production of neoantigens by tumour cells can lead to ...
In addition, a better understanding of CD-4 T cell memory is also a result of studies with LCMV and will continue to contribute ... It triggers a vigorous cytotoxic T lymphocytes (CTL) response and thus, it is cleared rapidly by the host. This is referred to ... indicates that it must first be transcribed into a positive mRNA strand before it can be translated into the required proteins ... Their key experiment involved harvesting of splenocytes containing LCMV-specific cytotoxic T lymphocytes(CTL) from an infected ...
CD4/CD8 lymphocyte counts in healthy, HIV-positive individuals & AIDS patients.. Authors: Ray, Krishna. Gupta, S M. Bala, Manju ... Ray K, Gupta SM, Bala M, Muralidhar S, Kumar J. CD4/CD8 lymphocyte counts in healthy, HIV-positive individuals & AIDS patients ... BACKGROUND & OBJECTIVES: The enumeration of CD4 and CD8 positive cells, surrogate markers for HIV disease progression, is ... In assessing the degree of immune deficiency in HIV-positive patients of a particular region, knowledge of reference range of T ...
CD4-Positive T-Lymphocytes. *. Li Wen, MD, PhD. Professor of Medicine (Endocrinology); Director of Core Laboratory of Yale ...
CD4-Positive T-Lymphocytes / cytology * CD4-Positive T-Lymphocytes / immunology* * CD8-Positive T-Lymphocytes / cytology ... Although early stages of T cell development were unperturbed, maturation of CD4 and CD8 single-positive (SP) thymocytes was ... TNF activation of NF-κB is essential for development of single-positive thymocytes J Exp Med. 2016 Jul 25;213(8):1399-407. doi ... experiments reveal an essential role for TNF activation of NF-κB to promote the survival and development of single positive T ...
CD4-Positive T-Lymphocytes. EN. dc.subject. CD8-Positive T-Lymphocytes. EN. ... T-Lymphocytes. EN. dc.title. T-lymphocyte subsets and thymic size in malnourished infants in Egypt: a hospital-based study. EN ... Thymus size was assessed ultrasonographically and correlated to the percentage of CD4 and CD8 T-lymphocytes in peripheral blood ... T-lymphocyte subsets and thymic size in malnourished infants in Egypt: a hospital-based study. Nassar, M ...
... to describe a group of lymphoproliferative disorders characterized by localization of neoplastic T lymphocytes to the skin. ( ... Immunologically, most neoplastic lymphocytes show an aberrant CD4-positive phenotype with clonal rearrangement of T-cell ... CD30-positive (75% or more) membrane staining of the large lymphocytes or large clusters of CD30-positive atypical lymphocytes ... Immunologically, atypical lymphocytes are CD4-positive, with variable loss of CD2, CD3, or CD5. ...
CD4-Positive T-Lymphocytes. Ehrlich AK, Pennington JM, Tilton S, Wang X, Marshall NB, Rohlman D, Funatake C, Punj S, ODonnell ... AhR activation increases IL-2 production by alloreactive CD4 T cells initiating the differentiation of mucosal-homing Tim3 Lag3 ...
In January 1991, his CD4 lymphocyte count was 253 cells/mm3, and serologic tests for syphilis and hepatitis B were negative. ... Patient G is a young man who contacted CDC after he tested positive for HIV antibody. In November 1990, he was first determined ... In May 1991, his CD4 lymphocyte count was 400 cells/mm3, and serologic tests for syphilis and hepatitis B were negative. ... with greater than 500 CD4 lymphocytes per mm3; serologic tests for syphilis and hepatitis B virus infection were negative. ...
All CD4 T-lymphocyte (CD4) results. *All HIV viral loads (both detectable and undetectable) ... Insurance companies can use the Notification of Positive HIV Status Form to report a positive HIV test. The purpose of this ... All supplemental tests for syphilis and HIV that result from an initial positive screening test, regardless of result (positive ... Positive and negative HIV DNA or RNA virologic test results for infants up to three (3) years of age ...
Most lymphocytes are T-cells (CD3 positive) and variably express nuclear TdT. Variable expression of CD4 and CD8 (smear pattern ... The flow cytometry profile of CD10 positive T-cell population with variable CD4 and CD8 is characteristic of thymic lymphocytes ... Once differentiated, almost all normal mature T-cells are either CD4 or CD8 positive, but never express both. Clonal T-cell ... Thymoma T-lymphocytes demonstrate variable expression (smear pattern) of CD4 and CD8 antigens. (e) ...
Immunological studies showed decreased levels of IgA, decreased number of CD3 positive T lymphocytes and decreased CD4 positive ... The main outcomes studied were the percentage of positive results to nickel patch tests, and changes in trends with time in an ... Future studies need to evaluate the yield (i.e., frequency of positive tests) of these detection methodologies in highly ... subject participation and yield of positive tests, however, have not been well defined. The major ... [Show full abstract] ...
keywords = "adaptor proteins, signal transducing, adjuvants, immunologic, animals, CD4-positive T-lymphocytes, caspases, ... t-lymphocytes, helper-inducer, tuberculosis vaccines, tuberculosis, pulmonary, vaccines, subunit", ...
TIGIT,sup,+,/sup, lymphocytes were seen in all 86 different tumour entities with considerable high variability of TIGIT ... Particularly, high densities of TIGIT,sup,+,/sup, lymphocytes were, for example, seen in squamous cell cancers of various ... The high frequency of TIGIT (and PD-1) expressing lymphocytes in cancers highlights considerable opportunities for cotargeting ... B lymphocytes. TIGIT expression paralleled that of PD-1. More than 70% of TIGIT,sup,+,/sup, cells were PD-1,sup,+,/sup ...
Genetic studies performed on LCNEC revealed that positive FOXp3 and tumor infiltrating lymphocyte (TiLS) represent favorable ... prognosis while CD4, CD8 and TiLS are an unfavorable prognosis factor. High presence of PD-L1 in LCNEC may constitute an ... The cases of SCLC that were negative for neuroendocrine markers tested positive for INSM-1 in 75% of cases. This indicated a ... Immunohistochemistry positive results for neuroendocrine markers, other than neuron specific enolase (NSA), can qualify the ...
The positive immune reactions were augmented from expansion of HPV specific interferon (IFN)-gamma-producing CD4(+) and CD8(+) ... T lymphocytes cells (Ding et. al., 2009). In a later study by Yin et al. (2010), Chinese researchers found that three unique ...
CD4 Lymphocyte Count Medicine & Life Sciences 96% * Chronic Renal Insufficiency Medicine & Life Sciences 87% ... Dive into the research topics of Kidney disease in antiretroviral-naïve HIV-positive adults with high CD4 counts: Prevalence ... Kidney disease in antiretroviral-naïve HIV-positive adults with high CD4 counts: Prevalence and predictors of kidney disease at ... title = "Kidney disease in antiretroviral-na{i}ve HIV-positive adults with high CD4 counts: Prevalence and predictors of ...
Proteintechs Mouse Monoclonal CD4 antibody is validated in FC and shows reactivity with Human samples. ... Positive FC detected in. Human peripheral blood lymphocytes. Recommended dilution. Application. Dilution. ... 1X10^6 human peripheral blood lymphocytes were surface stained with 0.06 ug PE-anti-human CD4 (PE-65134, clone OKT4) (red) or ... 1X10^6 human peripheral blood lymphocytes were surface stained with 0.06 ug PE-anti-human CD4 (PE-65134, clone OKT4) (red) or ...
en] Acquired Immunodeficiency Syndrome ; Receptors, Cell Surface ; Lymphocytes ; Humans ; CD4-Positive T-Lymphocytes ; B- ... Lymphocytes ; Apoptosis ; Antigens, Surface ; Antigens, CD95 ; Animals ; Tumor Cells, Cultured. Permalink :. http://hdl.handle. ...
Those with HIV infection were excluded if the T-helper lymphocytes CD4 positive count was , 250/mm3. We also excluded patients ... 36 of these gave a positive result, which meant that 13.7% of all patients in the study had a positive culture [9]. ... Positive sputum culture was demonstrated in only a small number of patients with CAP; this did not affect antimicrobial therapy ... Patients with a positive sputum culture for aerobic Gram-negative bacteria were more likely to receive ciprofloxacin and ...
She studies HIV, virus latency, CD4-positive T-... ... She studies HIV, virus latency, CD4-positive T-Lymphocytes, HIV ... infections, highly active antiretroviral therapy, T-lymphocytes, virus replication, viremia, viral overload and disease ...
CD1a-positive cells are consistent with Langerhans cell histiocytosis. A lymphocyte-predominant BAL with an elevated CD4/CD8 ... Stool occult blood results may be positive in patients with pulmonary haemorrhage; indeed these children may have undergone ... positive bronchiolitis, which fails to resolve;12 there is animal evidence that RSV causes increased inflammation and worse ... but the yield of positive results is much less. ...
Quantitative evaluation of T-lymphocyte subtypes. Sections stained for CD4+-, CD8+-, CCR7+-, or FoxP3+-lymphocytes were scored ... Cut-off value to discriminate between high and low lymphocyte infiltration was determined as 20 positive cells both for CCR7+- ... We also report a correlation among tumor infiltration by both Tccr7s and Tregs (CD4+FOXP3+) lymphocytes and patients outcome. ... We were unable to show any correlation among Tccr7 infiltration and: (i) total lymphocyte density; (ii) CD8+/CD4+ T-cell tumor ...
CD8+ and CD4+ T cells were gated from single cells (FSC-A vs FSC-H), lymphocytes (FSC-A vs SSC-A) and live CD3+ T cells (CD3+ ... vs Near-IR−), successively, and the detection results were defined as the percentage of cytokine-positive cells among CD8+ or ... T cells or CD4+ T cells at week 2, with a higher level in the IM group than in the IN group (Fig. 1i, j). Dose-dependent ... anti-CD4 Alexa Fluor 700 (clone RM4-5, 1:330 dilution), and anti-CD8 FITC (clone 5H10-1, 1:200 dilution), and the viability dye ...
Upon presentation at the hospital, HIV-positive people with COVID-19 had low total lymphocyte levels and decreased CD4 T cell ... lymphocyte. A type of white blood cell that is important in the immune system. Includes B cells (B lymphocytes, which produce ... Looking at differences between 19 HIV-positive people who died of COVID-19 and 53 HIV-positive people who recovered, those who ... Participants had a CD4 count of 554 cells/mm3 prior to COVID-19 diagnosis and a nadir or lowest-ever level of 320 cells/mm3. ...
After decalcification, the lymphocyte subsets (CD3, CD4, CD8, CD20) in the bone marrow component of each enthesis were measured ... Each section was examined by two observers, and positive cells were counted in several fields in the bone marrow part, just ... Thus it is not known whether B or T lymphocytes predominate in SpA related enthesitis, or whether the CD4 or the CD8 subset ... For the evaluation of CD4+ cells, only cells with lymphocyte morphology were included, because CD4 may be expressed by ...
... and are associated with the infiltration of interferon γ and TNFα-secreting CD4-positive lymphocytes in skin lesions and nerves ... Even after a ten-year MDT programme, more than 5% of healthy individuals in a leprosy-endemic area were positive for M. leprae ... It is widely believed that the leprosy elimination campaign has been a positive one. A comparably large consensus must now come ...
This procedure allows CDC to determine the distribution of CD4 cells in a random sample of HIV-positive individuals. NHANES is ... If the EIA was positive and the WB was positive, the result was coded as positive. If the EIA was positive or indeterminate but ... LBXCD4 - CD4 counts (cells/mm3). Variable Name: LBXCD4. SAS Label: CD4 counts (cells/mm3). English Text: CD4 counts (cells/mm3) ... Enumeration of CD4+ lymphocytes in HIV-positive participants and age-matched controls was performed on cryopreserved whole ...
  • IMSEAR at SEARO: CD4/CD8 lymphocyte counts in healthy, HIV-positive individuals & AIDS patients. (
  • In assessing the degree of immune deficiency in HIV-positive patients of a particular region, knowledge of reference range of T-cell subset counts of healthy individuals of that particular region is essential. (
  • Little is known about the prevalence of CKD in individuals with high CD4 cell counts prior to initiation of antiretroviral therapy (ART). (
  • International Network for Strategic Initiatives in Global HIV Trials (INSIGHT) START Study Group 2015, ' Kidney disease in antiretroviral-naïve HIV-positive adults with high CD4 counts: Prevalence and predictors of kidney disease at enrolment in the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial ', HIV Medicine , vol. 16, no. (
  • T-lymphocyte counts, with special emphasis and stunted children has not changed dra- on the effect of nutritional rehabilitation. (
  • The CD4 cell counts were obtained by using the Becton Dickinson MultiTEST reagent in TrueCOUNT tubes (Becton Dickinson Immunocytometry Systems, San Jose, CA). Comparison of this method with CD4 counts calculated from CBC absolute lymph counts from fresh whole blood X CD4% from the frozen whole blood resulted in a correlation coefficient of 0.9872. (
  • Comparative study of the plasma globulin level, CD21 − B-cell counts and FOXP3 mRNA expression level in CD4 + T-cells for different clinical stages of feline immunodeficiency virus. (
  • CD4 cell counts normally range from 500 to 1,600 (1,000 average) per cubic millimeter of blood. (
  • defined as HIV infection for greater than or equal to 13 years, no drug treatment, CD4 counts over 600, no decrease in CD4 for 5 years, and viral load less than 5000. (
  • Viral loads and CD4 counts should be followed for treatment response, and other labs may be needed to monitor drug side effects. (
  • Following diagnosis of acute HIV infection, two sets of CD4 lymphocyte counts and HIV viral load levels should be checked within four to six weeks to monitor level of immune suppression and viremia. (
  • The peripheral immune system was studied by assessment of circulating white blood cell counts, cellular changes of the spleen and influx of peripheral immune cells (MPO-positive neutrophils) into the brain. (
  • CD4 counts (also known as T-helper cells) provide a measure of a person's immune function. (
  • Among HIV-infected individuals, measurement of CD4 counts is often used to demonstrate how well anti-HIV drugs are working. (
  • 136 (21%) had CD4 counts above 350 cells per μL and had never received antiretroviral therapy. (
  • The present cross-sectional study was undertaken to determine the reference range of T-cell subsets in healthy north Indians and to compare the values with those in HIV-positives. (
  • The study revealed thymus atrophy in patients with PEM, especially the oedematous type, accompanied by changes in the peripheral lymphocyte subsets. (
  • The level of The infants with PEM were enrolled in T-lymphocyte subsets in peripheral blood the study after fulfilling a set of inclusion provide information about the development criteria. (
  • After decalcification, the lymphocyte subsets (CD3, CD4, CD8, CD20) in the bone marrow component of each enthesis were measured by an immunohistochemical technique. (
  • Most notably, no information has been reported on the quantitative distribution of the various cell types and lymphocyte subsets. (
  • High incidence of activating STAT5B mutations in CD4-positive T-cell large granular lymphocyte leukemia. (
  • BACKGROUND & OBJECTIVES: The enumeration of CD4 and CD8 positive cells, surrogate markers for HIV disease progression, is helpful in management and follow up of immunocompromised HIV-positive patients. (
  • RESULTS: In group I, the CD4 and CD8 levels were 687 +/- 219 and 611 +/- 288 cells/microl in males and 740 +/- 255 and 546 +/- 246 cells/microl in females. (
  • Overall, a significant depressed level of CD4 (525 +/- 207 cells/microl) and elevated level of CD8 (1174 +/- 484 cells/microl) in group II and (170 +/- 115 and 1051 +/- 586 cells/microl) respectively in group III were observed. (
  • These experiments reveal an essential role for TNF activation of NF-κB to promote the survival and development of single positive T cells in the thymus. (
  • 2017. AhR activation increases IL-2 production by alloreactive CD4 T cells initiating the differentiation of mucosal-homing Tim3 Lag3 Tr1 cells. . (
  • his white blood cell count was 3300/mm3 (normal: greater than 4000 cells/mm3) with a lymphocyte count of 693/mm3 (normal: greater than 1000/mm3). (
  • In January 1991, his CD4 lymphocyte count was 253 cells/mm3, and serologic tests for syphilis and hepatitis B were negative. (
  • Flow cytometry reveals mature T and B-cells (minor subset) along with a population of immature T-cells, which express both CD4 (variable) and CD8 (variable). (
  • Histologic sections show a biphasic tumor composed of spindled epithelial cells and occasional polygonal epithelial cells admixed with equal proportion of lymphocytes. (
  • Immunostains are performed and they show the following: The epithelioid cells are positive for cytokeratin. (
  • Most lymphocytes are T-cells (CD3 positive) and variably express nuclear TdT. (
  • Variable expression of CD4 and CD8 (smear pattern) is also noted, with some cells expressing both CD4 and CD8. (
  • TIGIT was detected in CD8 + cytotoxic T cells, CD4 + T helper cells, FOXP3 + regulatory T cells, and NK cells, but not in CD11c + dendritic cells, CD68 + macrophages, and CD20 + B lymphocytes. (
  • TIGIT expression is restricted to T lymphocytes and highly expressed in effector and regulatory CD4 + T cells, follicular helper CD4 + T cells, effector CD8 + T cells, and NK cells [ 6 , 7 , 9 - 12 ]. (
  • CD4 helper T-cells which alert the immune the studied infants were from low socio- system to an attack by a pathogen and the economic status families according to the CD8 suppressor T-cells which destroy cells classification of Park and Park [11]. (
  • However, about one in five had a CD4 count below 200 cells/mm 3 , reflecting advanced immune suppression. (
  • This procedure allows CDC to determine the distribution of CD4 cells in a random sample of HIV-positive individuals. (
  • HIV infection is characterized by a decrease and, eventually, a depletion of CD4+ T-lymphocytes (helper T cells). (
  • Using immunophenotyping, HIV-positive blood samples and age-matched controls were tested for the proportion of lymphocytes that are T cells, B cells, natural killer (NK) cells, CD4+ T cells (helper T cells), and CD8+ T cells (suppressor/inducer T cells). (
  • Within the thymus, thymus cell lymphocytes or T cells mature. (
  • T cells that successfully develop react appropriately with MHC immune receptors of the body (called positive selection ) and not against proteins of the body (called negative selection ). (
  • These are often associated with cancer of the tissue of the thymus, called thymoma , or tissues arising from immature lymphocytes such as T cells, called lymphoma . (
  • A key marker of HIV progression is the decline of CD4 positive (CD4+) T cells - the immune system's "helper" cells. (
  • The subset of lymphocytes known as T cells are so called because their final stage of development occurs in the thymus. (
  • 5 ) HIV's propensity is to attach to CD4 cells, and when these cells mobilize to fight infection by replicating, more HIV copies are made. (
  • 6 The CD4 cells are now infected and disarmed, which in turn disables other parts of the system, such as communication that stimulates B cells (for antibodies) into action. (
  • 8 Another marker of HIV is the ratio of CD4 to CD8 cells, an indicator of immune status. (
  • A healthy ratio is about one to two CD4 cells to every CD8 cell. (
  • Although values range from one individual to another, typically in HIV infection there is a dramatic drop not only in CD4 count, but also in the CD4-to-CD8 ratio, indicating a serious depletion of T-helper cells. (
  • His CD4 lymphocyte count, or a test that measures how many of these white blood cells are in the blood, was still normal at the time of the positive test in July. (
  • Complete eradication of the human immunodeficiency virus, type 1 (HIV-1) from infected individuals is not currently possible due, in part, to continuing presence of virus in lymphocytes and cells of the macrophage lineage [ 1 - 3 ]. (
  • Additionally, these nondividing cells differ in many respects from that of CD4 lymphocytes making them unique entities for long-term persistence of HIV DNA [ 4 , 10 ]. (
  • At that time the CD4 lymphocyte count was 50 cells/ml and the viral load was 19,000 RNA copies/ml. (
  • Laboratory tests will show low lymphocytes with atypical forms, depletion of the CD4 cells, elevated CD8 cells. (
  • Percent CD4 and CD3 were decreased, whereas natural killer cells were increased. (
  • Cells were then stained with Th-POK (clone 11H11A14) PE (filled histogram: CD4-positive cells, open histogram with solid line: CD8-positive cells) or mouse IgG1, κ PE isotype control (open histogram with dotted line: CD4-positive cells, open histogram with dashed line: CD8-positive cells). (
  • These findings suggest that Th-POK is essential in promoting commitment of immature T cells to the CD4 lineage and maintaining the characteristics of mature CD4+ T helper cells. (
  • The patient's CD4 count is 4 cells/mm 3 (normal range, 500-1600 cells/mm 3 ), and the HIV polymerase chain reaction (PCR) shows a viral load of 341,493 copies/mL. (
  • The serum HIV-1-RNA was 1.2 × 10 5 copies/m l , and the absolute CD4 lymphocyte count was 141 cells/m l . (
  • These might have been present in patients with a CD4 T lymphocyte count of more than 200 cells/m l . (
  • Thus COVID virus not only can gain entry to host cells via the spike protein, it's receptor binding sites, ACE-2 cell surface receptors, and with the insertion of the furin cleavage site at the juncture of the S1 and S2 sub-unit, but this study showed that the virus can also gain entry to lymphocytes of the immune system (white blood cells known as T-cells). (
  • However, whether lymphocytes are targets of viral infection is yet to be determined, although SARS-CoV-2 RNA or antigen has been identified in T cells from patients. (
  • Here, we confirmed that SARS-CoV-2 viral antigen could be detected in patient peripheral blood cells (PBCs) or postmortem lung T cells, and the infectious virus could also be detected from viral antigen-positive PBCs. (
  • Next, we demonstrate that viral antigen-positive T cells from patient undergone pronounced apoptosis. (
  • The relationship between B cells and CD4 T cells has been carefully studied, revealing a collaborative effort in which B cells promote the activation, differentiation, and expansion of CD4 T cells while the so-called "helper" cells provide signals to B cells, influencing their class switching and fate. (
  • It is primarily expressed on dendritic cells, NK cells, a subset of intestinal intraepithelial lymphocytes (IEL), and some activated T cells. (
  • Primary human CD4+CD45RO+ T cells were isolated from peripheral blood (PB) mononuclear cells (MNCs) using negative immunomagnetic separation techniques. (
  • CD4 and CD45RO are co-expressed on memory CD4+ T cells. (
  • INTERPRETATION & CONCLUSION: Our findings on T-cell subset reference ranges of normal healthy north Indians validate the utility of determination of CD4 cell count as a useful predictor of AIDS in Indian conditions and confirm that a significant per cent of AIDS patients had CD4 cell count below 200/microl. (
  • 11 According to Centers for Disease Control and Prevention (CDC) standards, a CD4 count below 200 (along with other symptoms) defines progression to AIDS, the most advanced stage of HIV-infection. (
  • Thymus size was assessed ultrasonographically and correlated to the percentage of CD4 and CD8 T-lymphocytes in peripheral blood in 32 infants with protein-energy malnutrition [‎PEM]‎ and compared with 14 healthy control infants. (
  • 1X10^6 human peripheral blood lymphocytes were surface stained with 0.06 ug PE-anti-human CD4 (PE-65134, clone OKT4) (red) or 0.06 ug PE-mouse IgG2b isotype control (blue). (
  • Human peripheral blood lymphocytes were surface stained with CD4 Brilliant Violet 421™ and CD8 Alexa Fluor® 647, and then were treated with True-Nuclear™ Transcription Factor Buffer Set. (
  • Ponesimod is a sphingosine 1-phosphate (S1P) receptor 1 modulator that binds with high affinity to S1P receptor 1 and blocks the capacity of lymphocytes to regress from lymph nodes, reducing number of lymphocytes in peripheral blood. (
  • These reactions occur in a third of patients with borderline forms of disease, are caused by spontaneous increases in T-cell reactivity to mycobacterial antigens, and are associated with the infiltration of interferon γ and TNFα-secreting CD4-positive lymphocytes in skin lesions and nerves, resulting in oedema and painful inflammation [ 2 ]. (
  • HLA-B27- and -B57-positive HIV-infected humans have long been associated with control of HIV replication, implying that CD8(+) T cell responses contribute to control of viral replication. (
  • The numerator is the number of persons aged ≥ 13 years whose HIV infection was diagnosed during the specified month/year and who had ≥ 1 CD4 or viral load (VL) test within 1 month of HIV diagnosis. (
  • Data are not provided for states and associated jurisdictions that do not have laws requiring reporting of all CD4 and viral loads, or that have incomplete reporting of laboratory data to CDC. (
  • Recent biochemical data has linked Brg1 function to genes important for T lymphocyte differentiation. (
  • The flow cytometry profile of CD10 positive T-cell population with variable CD4 and CD8 is characteristic of thymic lymphocytes, in the process of early maturation. (
  • All enrolled thymic lymphocytes is widely accepted as infants were breastfed in addition to receiv- an indicator of the depression of thymus- ing some traditional foods, according to dependent immune competence associated their age. (
  • Novel immune therapies using antibodies against immune checkpoint receptors, such as cytotoxic T lymphocyte antigen-4 (CTLA-4) and cell death protein-1 (PD-1), have demonstrated remarkable clinical efficiency in different tumour types, including metastatic melanoma, lung cancer, renal, and bladder carcinoma [ 1 - 3 ]. (
  • 12213222). CD4 is an accessory protein for MHC class-II antigen/T-cell receptor interaction. (
  • During this hospitalization a lumbar puncture demonstrated elevated opening pressure, a positive CSF cryptococcal antigen, and a positive India ink, consistent with crytpococcal meningitis. (
  • Serum cryptococcal antigen testing was also positive. (
  • Here we report a case of typical NPTCL-TFH while the B cell marker CD20 is positive. (
  • However, with all these evidences of NPTCL-TFH, the tissue weirdly expressed CD20, a B lymphocyte maturing marker. (
  • We report the first case of CD20 positive in a NPTCL-TFH. (
  • In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T-lymphocytes. (
  • Subjects with and without HAD were recruited and matched for age, gender, education, and CD4 cell count. (
  • Association of asymptomatic oral candidal carriage,oral candidiasis and CD4+ lymphocyte count in HIV-positive patients in China. (
  • Tumor necrosis factor superfamily 14 (TNFSF14) (LIGHT) is an interesting costimulatory molecule associated with T lymphocyte activation, and it mainly exerts its biological effects by binding to its receptors herpesvirus invasion mediator (HVEM) and lymphotoxin-ß receptor. (
  • Titi was born the following important background information for a routine can you buy zyloprim Pap test (age-adjusted), below the Healthy People 2020 targets for the average start time policies are in local spread of the 50 states, the District of Columbia had an obesity prevalence occurred in patients with acute HIV infection and progressively depletes CD4 lymphocytes, which are regions with this organism. (
  • Ayahuasca and amphetamine induced similar time-dependent modifications in lymphocyte subpopulations. (
  • The main disadvantage of kaolin induction is that the inflammatory reaction, composed of macrophages and CD4- and CD8-positive lymphocytes [33] , might confound interpretation of microglial reactions in these animal models. (
  • Thus it is not known whether B or T lymphocytes predominate in SpA related enthesitis, or whether the CD4 or the CD8 subset contributes most of the T lymphocytes in the infiltrates. (
  • These results suggest potentially positive effects of probiotics on core autism symptoms in a subset of ASD children independent of the specific intermediation of the probiotic effect on GI symptoms. (
  • Gastric mucosal alpha(4)beta(7)-integrin-positive CD4 T lymphocytes and immune protection against helicobacter infection in mice. (
  • HIV CD4 seroprevalence trends infection were also seen. (
  • Therefore, reports of confidential test results may not repre-sent all persons who tested positive for HIV infection. (
  • Cutaneous T-cell lymphoma (CTCL) (see the image below) is a heterogeneous group of lymphoproliferative disorders characterized by localization of neoplastic T lymphocytes to the skin, with no evidence of extracutaneous disease at the time of diagnosis. (
  • however, the serum cytomegalovirus antibody test result is positive. (
  • Enumeration of CD4+ lymphocytes in HIV-positive participants and age-matched controls was performed on cryopreserved whole blood using the method reported by Fiebig et. (
  • Quantitative reverse transcription PCR (qRT-PCR) ( 4 ) of the patient's specimen was positive, and he was admitted to the hospital. (
  • Although early stages of T cell development were unperturbed, maturation of CD4 and CD8 single-positive (SP) thymocytes was blocked in mice lacking IKK1/2 in the T cell lineage. (
  • Also, the term "primary cutaneous CD4 + small/medium T-cell lymphoma" was changed to "primary cutaneous CD4 + small/medium T-cell lymphoproliferative disorder" because of its indolent clinical behavior and uncertain malignant potential. (
  • Particularly, high densities of TIGIT + lymphocytes were, for example, seen in squamous cell cancers of various origins. (
  • Tumour infiltrating lymphocytes (TILs) expressing TIGIT have been demonstrated in several tumour types such as nonsmall cell lung cancer, colorectal carcinoma, melanoma, and acute myeloid leukaemia [ 9 , 13 , 14 ]. (
  • The Cambridge Biotech HIV-1 Western Blot Kit is manufactured by Calypte Corporation from HIV-I propagated in an H9/HTLV-IIIb T-lymphocyte cell line. (
  • It has been previously found that hTERT activity is down-regulated by the human T cell leukaemia virus type 1 (HTLV-1) Tax protein in HTLV-1 transformed T lymphocytes. (
  • There was no increase in NK cell activity in patients with high CD 4 + lymphocytes and only a marginal increase in patients with low CD 4 + lymphocytes (170 to 293/mm3) whereas a marked increase was observed in controls (252 to 490/mm3). (
  • The present study was aimed to assess the efficacy of an indigenous HBV vaccine in HIV positive patients harboring mainly clade C [ 6 ] and to study the different cell populations with their functional attributes especially in relation to HBsAb formation. (
  • The HIV virus has selective tropism for the T4 cell which expresses the CD4 phenotypic marker, a receptor for HIV . (
  • 1993. Decrease of CD4-positive T lymphocytes in workers exposed to benzidine and beta-naphthylamine. (
  • COVID-19 case ascertainment based on positive serologic test results is also no longer relevant, as surveillance should focus on incident cases only. (
  • A low ratio of CD4+ (helper) any chromosomal or hereditary disorder lymphocytes relative to CD8+ (suppressor) that caused the malnutrition. (
  • 3112582). CD4 serves as a receptor for the human immunodeficiency virus (HIV) (PMID: 9304802). (
  • El virus VIH posee un tropismo selectivo para las células T4 que expresan el marcador fenotípico CD4, un receptor para el VIH. (
  • Chief Medical Officer proliferation of CD4-positive T lymphocytes. (
  • The expression of hTERT , encoding the catalytic subunit of telomerase, plays a crucial role in the control of lymphocyte proliferation by maintaining telomere homeostasis. (
  • These findings support the notion that Tax, telomerase and shelterin play a critical role in the proliferation of HTLV-1 transformed T lymphocytes. (
  • To investigate the role of SWI-SNF-related complexes in this lineage, we ablated Brg1 function in T lymphocytes. (
  • This work highlights the relevance of the Mamu-B*08-positive SIV-infected Indian rhesus macaque as a model to examine elite control of immunodeficiency virus replication. (
  • Over the past decade, teams at Touch Research Institute(TRI) in Miami, Fla., have conducted several studies investigating the effects of massage therapy on immune system function in HIV-positive children and adults. (
  • The researchers found that most outcomes did not differ between the HIV-positive and HIV-negative patients, including length of stay in hospital (five days in both groups), rates of acute kidney injury or likelihood of death while hospitalised (22% vs 24%, respectively). (
  • We identified 30 patients (22.0%) with positive anti-MDA5, 42 patients (31.0%) with positive anti-Jo-1 and 64 patients(47.0%) with other anti-ARS. (
  • The application of PSL pulse and IVIG are not necessarily an effective treatment for positive anti-MDA5 patients. (
  • Prior reports for the patients with anti-aminoacyl-tRNA synthetase(ARS) antibodies revealed different manifestations in patients that were positive and negative [ 11 - 13 ] . (
  • hence, pSTAT5B expression may be an indicator of positive prognosis in patients with MCC. (
  • The aim of the present study was to assess the efficacy of recombinant vaccine in treatment-naive HIV positive patients and healthy controls, and to dissect out differences if any, in different limbs of immune response. (
  • Forty HIV positive patients and 20 HIV negative controls, negative for HBsAg, HBsAbs and HBcAbs were vaccinated with three doses of 40μg and 20μg of vaccine respectively. (
  • HBsAb titers were much lower in HIV positive patients compared to controls. (
  • There are conflicting reports of antibody response against HBV vaccine in HIV positive patients depending upon the stage of the disease. (
  • HLA-DQ allele-restricted activation of nitroso sulfamethoxazole-specific CD4-positive T lymphocytes from patients with cystic fibrosis. (
  • Diverse populations of functionally mature but naive lymphocytes are generated in the absence of foreign Ags in the primary lymphoid organs (thymus, fetal liver, and bone marrow). (
  • The muscle biopsy revealed moderate neuromyopathic findings with positive expression for MHC-class I, C5b9, CD8 and CD68. (
  • PE-65134 targets CD4 in FC applications and shows reactivity with Human samples. (
  • Two of these Mamu-B*08-positive animals subsequently lost control of SIV replication. (
  • We first provide evidence that the up-regulation of hTERT transcription in activated CD4+ T lymphocytes is associated with a down-regulation of that of TERF1, TERF2 and POT1 genes. (
  • Next, the down-regulation of hTERT transcription by Tax in HTLV-1 transformed or in Tax-expressing T lymphocytes is found to correlate with a significant increase of TRF2 and/or Pot1 mRNAs. (
  • Chest computed tomography (CT) scan of a patient on hemodialysis diagnosed with positive reverse transcription PCR for severe acute respiratory syndrome coronavirus 2 in hemodialysis effluent, Japan. (
  • Diagnosis of leprosy is mostly clinical and symptomatic, based on the presence of a few cardinal signs: hypopigmented or reddish-copper patches with definite sensory loss, with or without thickened nerves, and positive skin smears [ 3 ]. (
  • Whole EDTA anti-coagulated blood stored at -70°C from the 31 HIV antibody-positive participants from NHANES 1999-2004 and 34 age-matched controls were used. (
  • The number of participants with negative QuantiFERON-TB Gold In-Tube findings at baseline who converted to positive by the end of the study was 38 (20%) of 186 in the MVA85A group and 40 (23%) of 173 in the placebo group, for a vaccine efficacy of 11·7% (95% CI -41·3 to 44·9). (