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 ...
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 ...
The CD8αβ coreceptor influences CD8 T cell recognition and responses in anti-tumor and -viral immunity. The ancestor to the human and chimpanzee CD8β gene acquired two additional exons absent in the mouse that lead to the expression of multiple isoforms (M1-M4) as a result of alternative splicing. In humans these isoforms differ in their cytoplasmic tails and in their expression pattern. The M-1 isoform is predominant in naïve T cells whereas M-4 is predominant in effector memory T cells. To study functional differences we are co-transducing CD8α, each CD8β isoform, and MHCI restricted NY-ESO-1 specific TCR into human CD4+ T cells and measuring cytokine production after activation. We have found differences in induction of cytokine producing cells such as the MIP-1β chemokine with different isoforms. The M-4 isoform cytoplasmic tail has unique sorting motifs that regulate its cell surface expression and it is modified by phosphorylation after activation. The cytoplasmic tail of M-4 could ...
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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 ...
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
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 …
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 ...
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 ...
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.
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 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 ...
T cell-dependent autoimmune diseases are characterized by the expansion of T cell clones that recognize immunodominant epitopes on the target antigen. As a consequence, for a given autoimmune disorder, pathogenic T cell clones express T cell receptor
Type 1 diabetes is associated with T\cell responses to \cell antigens such as GAD65. a potentially autoreactive repertoire. Without depleting CD25+ cells, GAD113C132 and GAD265C284 responses were significantly stronger in subjects with diabetes. Although nearly every individual responded to at least one GAD65 epitope, most were seen in less than half of the subjects tested, suggesting that multiple epitopes are recommended for TSPAN9 immune monitoring. biotinylation, class II monomers were loaded with either peptide pools or individual peptides by incubating for 48?hr at 37 with 25\fold molar excess of peptide (total) in phosphate buffer, pH 60 in the presence of 02% culture growth using CD25 microbeads (Miltenyi Biotec) as previously described to remove regulatory T cells and increase the magnitude of responses.19 In a second set of experiments, responses were evaluated without removing CD25+ cells. CD4+ T cells (or CD4+?CD25 T cells) were seeded in 48\well plates at 25??106?cells/well in ...
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 ...
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 ...
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., ...
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 ...
... principally the CD4+ T-Helper lymphocytes. As well as lymphocytes, CD4 receptors are also present on the surface of macrophages ... Patients that are HIV positive have increased risk of developing infections and tumours. The severity of illness is greater the ... and probably many other sites.The normal CD4 count is 500-1500 therefore patient's with HIV have a CD4 count less than 500. ... A CD4 count less than 200 is a diagnosis of Acquired Immunodeficiency Syndrome (AIDS). Oral manifestation of HIV include ...
... 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, ...
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 ...
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 ...
... 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 ...
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 ... al., 2010) triple positive T cells, αβTCRlowCD4+CD8+ within the spaces formed by the interlocking of the membrane. Some of ... found in their study that one-fourth of the nurse cells isolated from mice were double-positives for K5 and K8, while the rest ...
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 ...
The number of CMV memory CD8 + T lymphocytes then predominate and the total number of available naïve T lymphocytes decrease. ... CD8+T cells form up to 50 % of all peripheral blood memory cells in HCV-positive elderly individuals. The same effect on the ... The amount of memory cells generated as a response to cytomegalovirus is approximately 9.1% - 10.2% of all circulating CD4 + ... This results in a population of migrating effector CD8 + T-lymphocytes and the second small population called central memory T- ...
This is called positive selection. During positive selection, co-receptors CD4 and CD8 initiate a signaling cascade following ... When primary lymphocytes are developing and differentiating in the thymus or bone marrow, T cells die by apoptosis if they ... It follows that MHC restriction is imposed by CD4 and CD8 co-receptors during positive selection of T cell selection. A ... T cell maturation involves two distinct developmental stages: positive selection and negative selection. Positive selection ...
... 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 ...
Women who test positive for thyroid antibodies may be at increased risk of developing symptoms associated with postpartum ... increased CD4:CD8 ratio) TSH-receptor antibodies (TSH-R Abs) This condition is commonly undiagnosed by physicians due to either ... increase in TPOAb subclasses IgG1-IgG3 lymphocyte infiltration and follicle formation within thyroid gland (Hashimoto's ...
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 ... Many HLA DQ were under positive selection of 10,000s potentially 100,000s of years in some regions. As people moved they have ... of Celiac Disease patients are positive for DQ2 or DQ8.[6] ...
MAIT cells were initially specified as T cells that do not express the TCR co-receptors CD4 or CD8 on the cell surface. However ... MAIT cells constitute a subset of αβ T lymphocytes characterized by a semi-invariant T cell receptor alpha (TCRα) chain. The ... Here, T cells rearrange their TCRs and are subjected to TCR affinity tests as a part of positive selection and negative ... MAIT cells are most common in the liver, where they usually comprise 20-40% of the T lymphocyte population. The total murine ...
"Clonal expansion of lymphocytes bearing the gamma delta T-cell receptor in a patient with large granular lymphocyte disorder". ... The neoplastic cells of this disease display a mature T-cell immunophenotype, with the majority of cases showing a CD4-/CD8+ T- ... Immunohistochemistry for perforin, TIA-1, and granzyme B are usually positive. Clonal rearrangements of the T-cell receptor ( ... The neoplastic lymphocytes seen in this disease are large in size with azurophilic granules that contains proteins involved in ...
Immunophenotype: CD3+/CD4-/CD8-/TCRalpha/beta+. *Measured by flow cytometry: Normal values ,2.5% total T cells; ,1% of total ... It is a rare genetic disorder of abnormal lymphocyte survival caused by defective Fas mediated apoptosis.[3] Normally, after ... Can have antibodies to blood cells (DAT, anti-neutrophil, anti-platelet). Also, can have positive ANA, RF, ANCA ... 2009). "FAS-L, IL-10, and double-negative CD4−CD8− TCR α/β+ T cells are reliable markers of autoimmune lymphoproliferative ...
In a healthy individual, the number of CD4+ lymphocytes is in balance with the cells generated by the bone marrow; however, in ... HIV proteins decrease the amount of CD4 glycoprotein marker present on the cell membrane. Released viral particles and proteins ... "Density gradient capacitation is the most suitable method to improve fertilization and to reduce DNA fragmentation positive ... In the case of HIV, CD4+ lymphocytes die at an accelerated rate through uncontrolled apoptosis, when stimulated. At the ...
PTSAgs induce the VB-specific expansion of both CD4 and CD8- subsets of T Lymphocytes. TSST-1 forms homodimers in most of its ... The explagr locus is one of the key sites of positive regulation for many of the S. aureus genes, including TSST-1. ...
CD4, CD8, CD28, Lck, and Fyn. p-SMAC (peripheral-SMAC) within which the lymphocyte function-associated antigen-1 (LFA-1) and ... The process thereby upregulates itself via positive feedback. Some parts of this process may differ in CD4+ and CD8+ cells. For ... Regulation of lymphocyte activation Transfer of peptide-MHC complexes from APCs to lymphocytes Directing secretion of cytokines ... CD8+ T lymphocytes contain lytic granules - specialized secretory lysosomes filled with perforin, granzymes, lysosomal ...
CD4+CD8+), and finally mature to single-positive (CD4+CD8− or CD4−CD8+) thymocytes that are then released from the thymus to ... A T cell, or T lymphocyte, is a type of lymphocyte (a subtype of white blood cell) that plays a central role in cell-mediated ... The process of positive selection takes a number of days.[34] Double-positive thymocytes (CD4+/CD8+) move deep into the thymic ... Double-positive cells (CD4+/CD8+) that interact well with MHC class II molecules will eventually become CD4+ cells, whereas ...
Double-positive cells (CD4+/CD8+) that interact well with MHC class II molecules will eventually become CD4+ cells, whereas ... A T cell is a type of lymphocyte which develops in the thymus gland and plays a central role in the immune response. T cells ... Double-positive thymocytes (CD4+/CD8+) move deep into the thymic cortex, where they are presented with self-antigens. These ... If the cell does not lose its signal, it will continue downregulating CD8 and become a CD4+, single positive cell.[6] ...
CD4-positive, CD25-positive, alpha-beta regulatory T cell lineage commitment. • positive regulation of CD4-positive, CD25- ... negative regulation of lymphocyte proliferation. • negative regulation of histone acetylation. • negative regulation of ... CD4-positive, CD25-positive, alpha-beta regulatory T cell differentiation. • positive regulation of transcription from RNA ... positive regulation of transcription, DNA-templated. • negative regulation of interleukin-2 production. • positive regulation ...
... or of infiltration of the epithelium lining by the types of lymphocytes seen in celiac disease. The lymphocytes in these ... Anaplastic large cell lymphoma, ALK positive (ALCL,ALK+): ALCL,ALK+ is a subtype of anaplastic large cell lymphoma. It commonly ... may express CD4, and usually do not express CD8. There is no standard treatment for MEITL. Most individuals have been treated ... Unlike MEITL, it is more commonly due to the proliferation of NK rather than T cell lymphocytes, in all cases is caused by ...
LymphocytesEdit. Main article: Lymphocyte. T and B lymphocytes are the cells of the adaptive immune system. The human body has ... most of the CD4+ helper cells die on resolution of infection, with a few remaining as CD4+ memory cells. ... immunity as they are uniquely capable of migrating to follicular B cells in secondary lymphoid organs and provide them positive ... In jawless fishes, two subsets of lymphocytes use variable lymphocyte receptors (VLRs) for antigen binding.[33] Diversity is ...
The research of Tsokos revealed that CD3 positive but CD4 and CD8 negative T cells are expanded in patients with SLE and ... His work confirmed that the T lymphocytes from patients with SLE display increased and aberrant early signaling response ... Double negative cells appear to derive from CD8 positive cells and only when the see autoantigen. This line of research has ... October 2012). "cAMP response element modulator α controls IL2 and IL17A expression during CD4 lineage commitment and subset ...
Helper T-cells or CD4+ T-cells express CD4 co-receptors. They bind to class II MHC molecules, which are only expressed in ... Hence, if a tetramer stain specific for a pathogenic peptide results in a positive signal, this may indicate that the person's ... Tetramer stains usually analyze cytotoxic T lymphocyte (CTL) populations. CTLs are also called CD8+ T-cells, because they have ... "The Adaptive Immune Response: T lymphocytes and Their Functional Types". Anatomy and Physiology II. Lumen Learning. Retrieved ...
一个T细胞的命运就在阳性选择的过程中被决定。在双阳性(CD4+/CD8+)T细胞中,能够与MHC-II分子结合得较好的将成为CD4+细胞,而和MHC-I分子有更高亲和力的将成为CD8+细胞。将成为CD4+细胞的细胞将会逐渐下调自己的CD8,最终成为单阳性 ... T细胞(英語:T cell、T lymphocyte)是淋巴细胞的一种,在免疫反應
... who was also HIV-positive.[57] From 60 matching donors, they selected a [CCR5]-Δ32 homozygous individual with two genetic ... This is due to a therapeutic immune reaction of the grafted donor T lymphocytes against the diseased bone marrow of the ... during which neither showed traces of HIV in their blood plasma and purified CD4 T cells using a sensitive culture method (less ...
APCs then present the fragments to T helper cells (CD4+) by the use of class II histocompatibility molecules on their surface. ... As of 2015 mass spectrometry resolution is insufficient to exclude many false positives from the pool of peptides that may be ... They become activated and start to secrete cytokines, substances that activate cytotoxic T lymphocytes (CTL), antibody- ... Cytotoxic T lymphocytes that recognize these antigens may be able to destroy tumor cells.[15] ...
Estadio I: A infección por VIH é asintomática cun reconto de células T CD4+ (ou reconto CD4) maior de 500/µL.[13] Pode incluír ... May, MT; Ingle, SM (2011 Dec). "Life expectancy of HIV-positive adults: a review". Sexual health 8 (4): 526-33. PMID 22127039. ... Alimonti JB, Ball TB, Fowke KR (2003). "Mechanisms of CD4+ T lymphocyte cell death in human immunodeficiency virus infection ... A razón desta preferencia pola perda das células T CD4+ da mucosa é que a maioría das células T CD4+ da mucosa expresan a ...
positive regulation of chemokine (C-X-C motif) ligand 2 production. • positive regulation of JUN kinase activity. • positive ... showed that TNFα causes an IL-10-dependent inhibition of CD4 T-cell expansion and function by up-regulating PD-1 levels on ... In 1968, Gale A Granger from the University of California, Irvine, reported a cytotoxic factor produced by lymphocytes and ... positive regulation of smooth muscle cell proliferation. • positive regulation of protein kinase activity. • positive ...
positive regulation of leukocyte migration. • platelet degranulation. • regulation of integrin activation. • cell adhesion. • ... PSGL-1 is situated on various hematopoietic cells such as neutrophils, eosinophils, lymphocytes, and monocytes, in which it ... positive regulation of platelet activation. • leukocyte migration. • response to lipopolysaccharide. • calcium-dependent cell- ... positive regulation of phosphatidylinositol 3-kinase signaling. • inflammatory response. • calcium-mediated signaling using ...
Due to the large numbers of apoptotic lymphocytes, the thymus was originally dismissed as a "lymphocyte graveyard", without ... First, T cells undergo "Positive Selection", whereby the cell comes in contact with self-MHC, expressed by thymic epithelial ... most of which express CD4. Autoimmune diseases are caused by a hyperactive immune system that instead of attacking pathogens ... are group of rare congenital genetic diseases that result in combined T lymphocyte and B lymphocyte deficiencies. These ...
B lymphocytes or T lymphocytes). Cytogenetic testing on the marrow samples can help classify disease and predict how aggressive ... Person with t(9,22) positive-ALL (30% of adult ALL cases) and other Bcr-abl-rearranged leukemias are more likely to have a poor ... CD2, CD3, CD4, CD5, CD7, CD8 - + TdT + + CytogeneticsEdit. Cytogenetic analysis has shown different proportions and frequencies ... on the cell surface can help differentiate malignant lymphocyte cells from reactive lymphocytes, white blood cells that are ...
... provides a positive control when studying immune-response of a new drug.[54] ... Elimination of T regulatory cells (CD4+CD25+ T cells) in naive and tumor-bearing hosts ... "Immunosuppressive effect of cyclophosphamide on white blood cells and lymphocyte subpopulations from peripheral blood of Balb/c ...
positive regulation of transcription, DNA-templated. • cellular response to lithium ion. • cell adhesion. • extracellular ... Lymphocyte homing receptor: CD44. *L-selectin. *integrin (VLA-4, LFA-1). *Carcinoembryonic antigen ... positive regulation of transcription factor import into nucleus. • pituitary gland development. • response to toxic substance. ...
positive regulation of flagellated sperm motility involved in capacitation. • lymphocyte migration. • T cell migration. • ... positive regulation of cytosolic calcium ion concentration. • positive regulation of epithelial cell migration. • dendritic ... positive regulation of dendritic cell chemotaxis. • signal transduction. • calcium-mediated signaling. • chemotaxis. • cell ... 1997). "Identification of CCR6, the specific receptor for a novel lymphocyte-directed CC chemokine LARC". J. Biol. Chem. 272 ( ...
Prevention of acute and chronic allograft rejection with CD4+CD25+Foxp3+ regulatory T lymphocytes. „Nat Med". 14 (1), s. 88-92 ... Wasp venom immunotherapy induces activation and homing of CD4(+)CD25(+) forkhead box protein 3-positive regulatory T cells ... Komórki te są słabiej zbadane od komórek CD4+Foxp3+;. *limfocyty T regulatorowe typu 1 (Tr1)[13] - komórki o fenotypie CD4+ ... Increased circulating regulatory T cells (CD4(+)CD25 (+)CD127 (-)) contribute to lymphocyte anergy in septic shock patients. „ ...
... adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Yuflyma, intended ...
"CD4/major histocompatibility complex class II interaction analyzed with CD4- and lymphocyte activation gene-3 (LAG-3)-Ig fusion ... positive regulation of natural killer cell mediated cytotoxicity. • antigen processing and presentation of exogenous peptide ... "Entrez Gene: LAG3 lymphocyte-activation gene 3".. *^ a b c Triebel F, Jitsukawa S, Baixeras E, Roman-Roman S, Genevee C, Viegas ... a novel lymphocyte activation gene closely related to CD4". The Journal of Experimental Medicine. 171 (5): 1393-405. doi: ...
... type B-positive with a type AB-positive graft) require eventual retransplantation, the recipient may receive a new organ of ... Lymphocytes include two classes that enact adaptive immunity, also called specific immunity. Lymphocytes of specific immunity T ... When memory helper T cells' CD4 receptors bind to the MHC class II molecules which are expressed on the surfaces of the target ... There is a risk of graft-versus-host disease (GVHD), however, whereby mature lymphocytes entering with marrow recognize the new ...
Mature Th cells express the surface protein CD4 and are referred to as CD4+ T cells. Such CD4+ T cells are generally treated as ... The key Th2 transcription factors are STAT6 and GATA3.[10] IL-4 is the positive feedback cytokine for Th2 cells differentiation ... These effects are primarily due to the loss of any helper T cell that can interact with the B lymphocyte correctly. Another ... CD4+ T cells have TCRs with an affinity for Class II MHC, and CD4 is involved in determining MHC affinity during maturation in ...
In 2007, Timothy Ray Brown,[12] a 40-year-old HIV-positive man, also known as "the Berlin Patient", was given a stem cell ... This protein is common to all HIV variants as it is the attachment point for B lymphocytes and subsequent compromising of the ... A cellular receptor, generally CCR5 or CXCR4 is required in order for HIV entry into CD4 cells. Cells of individuals homozygous ... HIV binds to immune cell surface receptors, including CD 4 and CXCR4 or CD4 and CCR5. The binding causes conformation changes ...
HHV-7 was first isolated in 1990 from CD4+ T cells taken from peripheral blood lymphocytes. Both HHV-6B and HHV-7, as well as ... To enter CD4+ T cells, HHV-7, unlike HHV-6, uses CD4 and possibly some cell-surface glyoproteins to enter CD4+ T cells. About a ... of them were positive for HHV-7. "Other Herpesviruses: HHV-6, HHV-7, HHV-8, HSV-1 and -2, VZV". American Journal of ... Lusso, P; Secchiero, P; Crowley, RW; Garzino-Demo, A; Berneman, ZN; Gallo, RC (1994). "CD4 is a critical component of the ...
It is reported that the company's HIV vaccine candidate is not toxic to 48 HIV-positive patients enrolled in a double-blind ... Results of phase 2 trials of 200 enrollees published in June 2016 were shown to be effective in increasing CD4 cell levels. In ... Watkins DI (March 2008). "The hope for an HIV vaccine based on induction of CD8+ T lymphocytes - A Review". Mem. Inst. Oswaldo ... This prophylactic drug is also used in combination with other mediums to treat HIV positive children over the age of twelve ...
positive regulation of G-protein coupled receptor protein signaling pathway. • immune response. • neuropeptide signaling ... D2 is a potent and selective CRTH2 receptor agonist and causes activation of human eosinophils and Th2 lymphocytes". ...
Positive-feedback mechanism to enhance allergic sensitization (B cells) FcαRI (CD89) IgA Low (Kd , 10−6 M) Monocytes. ... On T lymphocytesEdit. CD4+ T cells provide help to B cells that produce antibodies. Several subsets of activated effector CD4+ ... Holgado, M. P., Sananez, I., Raiden, S., Geffner, J. R., and Arruvito, L. (2018) CD32 Ligation Promotes the Activation of CD4 ... The positive B cell signaling is initiated by binding of foreign antigen to surface immunoglobulin. The same antigen-specific ...
Lymphocyte-rich. Is a rare subtype, show many features which may cause diagnostic confusion with nodular lymphocyte predominant ... On the other hand, its positive predictive value is high enough for it to be regarded as a pathognomonic sign of Hodgkin ... such as CD2 and CD4) are occasionally expressed.[26] However, this may be an artifact of the ambiguity inherent in the ... Nodular lymphocyte predominant Hodgkin lymphomaEdit. Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is another subtype ...
... adopted a positive opinion for ustekinumab for the treatment of moderate to severe plaque psoriasis in adult patients who ... Interleukin 16 (signals through CD4). *Interleukin 24 (signals through IL-22Rα1/IL-20Rβ heterodimer) ...
CD4 cells are necessary to help protect the body from infections and cancer.[20] Since the HIV virus destroys CD4 cells, it ... Specifically, vitamin A and zinc have shown positive health effects.[26] There are no major negative side effects of vitamin ... Scanning electron micrograph of HIV-1 (in green) budding from cultured lymphocyte. Multiple round bumps on cell surface ... It is recommended to start HAART if a person has HIV and has a CD4 cell count of less than or equal to 350 cells/mm3. This ...
positive regulation of cell proliferation. • T cell activation. • cell adhesion. • Viral entry. • regulation of insulin ... "CD26/dipeptidyl peptidase IV in lymphocyte growth regulation". Advances in Experimental Medicine and Biology. 421: 127-40. doi: ...
positive regulation of interleukin-4 production. • positive regulation of interleukin-10 production. • positive regulation of T ... In the macrophage, the primary signal for activation is IFN-γ from Th1 type CD4 T cells. The secondary signal is CD40L on the T ... CD40 ligand is primarily expressed on activated CD4+ T lymphocytes but is also found in a soluble form. While CD40L was ... positive regulation of endothelial cell apoptotic process. • B cell proliferation. • isotype switching. • immune response. • ...
... including CD4+, CD8+, B lymphocytes and natural killer cells. CD38 also functions in cell adhesion, signal transduction and ... positive regulation of cell growth. • positive regulation of B cell proliferation. • positive regulation of vasoconstriction. • ... positive regulation of insulin secretion. • negative regulation of bone resorption. • NAD metabolic process. • positive ... "Modulation of CD4 lateral interaction with lymphocyte surface molecules induced by HIV-1 gp120". European Journal of Immunology ...
一个T细胞的命运就在阳性选择的过程中被决定。在双阳性(CD4+/CD8+)T细胞中,能够与MHC-II分子结合得较好的将成为CD4+细胞,而和MHC-I分子有更高亲和力的将成为CD8+细胞。将成为CD4+细胞的细胞将会逐渐下调自己的CD8,最终成为单阳性 ... T细胞(英語:T cell、T lymphocyte)是淋巴细胞的一种,在免疫反應
P2.146 CD4 Lymphocytes Count At First Presentation of HIV Positive Patients Accessing Antiretroviral Therapy At a District ... P2.146 CD4 Lymphocytes Count At First Presentation of HIV Positive Patients Accessing Antiretroviral Therapy At a District ... The study determined the CD4 lymphocytes count levels of HIV positive patient at first presentation at STI/HIV Clinic at ... of all HIV positive patients presented with CD4 count of less than 250 cells/mm3. 20.7% (183/883) reported with CD4 count less ...
CD4-Positive and CD8-Positive Cytotoxic T Lymphocytes Contribute to Human Papillomavirus Type 16 E6 and E7 Responses. Mayumi ... CD4-Positive and CD8-Positive Cytotoxic T Lymphocytes Contribute to Human Papillomavirus Type 16 E6 and E7 Responses ... CD4-Positive and CD8-Positive Cytotoxic T Lymphocytes Contribute to Human Papillomavirus Type 16 E6 and E7 Responses ... CD4-Positive and CD8-Positive Cytotoxic T Lymphocytes Contribute to Human Papillomavirus Type 16 E6 and E7 Responses ...
In order to determine the fine structural differences and labeling by immunoferritin particles of CD4-positive (CD4+) and CD8 ... Immunoelectron-microscopic study of CD4- and CD8- positive lymphocytes from healthy donors seropositive for human T- ... In order to determine the fine structural differences and labeling by immunoferritin particles of CD4-positive (CD4+) and CD8 ... Sera of eight donors were all positive on the particle agglutination (PA) test, but only of the four of the eight were positive ...
Percentages of CD4+CD8+ Double-positive T Lymphocytes in the Peripheral Blood of Adults from a Blood Bank in Bogot , Colombia. ... Percentages of CD4+CD8+ Double-positive T Lymphocytes in the Peripheral Blood of Adults from a Blood Bank in Bogot , Colombia. ... Keywords: Flow cytometry, Lymphocyte, Lymphocyte subpopulation, T lymphocytes. Kolombiya Bogota Kan Bankas Yeti kin Periferik ... Objective: CD4+CD8+ double-positive T-cells (DPTs) have been classified as a separate T-cell subpopulation, with two main ...
CD4+ T cells were used as positive controls. The RNA was extracted and analyzed for CD4 and glyceraldehyde-3-phosphate ... The CD4 antigen was immunoprecipitated from SEB-activated CD4-depleted PBMC (,0.5% CD3+CD4+) and probed by Western blot for CD4 ... Such elements include the CD4 promoter (34), the CD4 enhancer (35), and the CD4 silencer (36-38). All of these CD4 constructs, ... CD4 mRNA can be detected in mature CD4+ T cells while no expression of CD4 mRNA could be detected in freshly isolated CD8+CD4− ...
CD4-CD8 RatioCD4-Positive T-Lymphocytes / immunologyCD8-Positive T-Lymphocytes / immunologyClinicalClinical Decision-Making / ... Tag : CD4-Positive T-Lymphocytes / immunology. Cardiology. Cytokine Storm in COVID-19-Immunopathological Mechanisms, Clinical ...
HLA-DQ allele-restricted activation of nitroso sulfamethoxazole-specific CD4-positive T lymphocytes from patients with cystic ... HLA-DQ allele-restricted activation of nitroso sulfamethoxazole-specific CD4-positive T lymphocytes from patients with cystic ...
To establish a safety record for cimetidine use in HIV-positive patients. ... A Study to Evaluate the Effect of Cimetidine on CD4 Lymphocyte Counts in HIV Infection. The safety and scientific validity of ... A Study to Evaluate the Effect of Cimetidine on CD4 Lymphocyte Counts in HIV Infection. ... To observe time-associated trends at weeks 4, 8, 12, and 16 in the change of CD4 counts for patients taking cimetidine for the ...
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 ...
p101-111 is the first CTA-derived peptide which induces CD4(+), CD8(+), and B-cell responses in vitro. This triple-immunogenic ... CD4-Positive T-Lymphocytes / immunology* * CD4-Positive T-Lymphocytes / metabolism * CD8-Positive T-Lymphocytes / immunology* ... A peptide epitope derived from the cancer testis antigen HOM-MEL-40/SSX2 capable of inducing CD4⁺ and CD8⁺ T-cell as well as B- ... Conclusions: p101-111 is the first CTA-derived peptide which induces CD4(+), CD8(+), and B-cell responses in vitro. This triple ...
CD4 positive cells from leukocytes; and lymphocytes from leukocytes.. The methods in accordance with the invention may also be ... Method and apparatus for lymphocyte separation from blood. US3970518 *. Jul 1, 1975. Jul 20, 1976. General Electric Company. ...
Lymphocytes. Interleukin-2. Drug Therapy, Combination. AIDS Vaccines. CD4 Lymphocyte Count. Cell Division. HIV Core Protein p24 ... Remune has been reported to increase lymphocyte proliferative responses to HIV antigens in patients with high CD4 cell counts. ... A Study to Test If Giving Remune (an HIV Vaccine) Can Improve the Immune Systems of HIV-Positive Patients Who Are Also ... Blood and skin tests are performed at Weeks 0, 8, 16, and 24 to measure immune response and lymphocyte proliferative responses. ...
The primary cellular receptor for HIV is CD4, but this molecule is insufficient to permit viral fusion. During 1996, the ... CD4 Antigens / physiology * CD4-Positive T-Lymphocytes / virology * Chemokines / physiology * Child * Dendritic Cells / ... The primary cellular receptor for HIV is CD4, but this molecule is insufficient to permit viral fusion. During 1996, the ...
CD4-Positive T-Lymphocytes. Treatment Naive. Latent HIV Infections. Additional relevant MeSH terms:. Layout table for MeSH ... Memory CD4 cells may provide a reservoir of latent HIV that cannot be completely eliminated using currently available anti-HIV ... CD4-cell subsets, cellular anti-HIV factors, and cellular drug transporters will be observed to determine which resting memory ... Characterization of memory CD4 cell subsets isolated from chemotherapeutically suppressed participants [ Time Frame: At the end ...
CD4-Positive T-Lymphocytes. *CD4-Positive T-Lymphocytes: immunology. *CD8-Positive T-Lymphocytes ... Among these, the NKG2D molecule was identified as expressed by T lymphocytes, including most CD8+ cells and a minority of CD4+ ... Moreover, NKG2D and TCR triggering was also observed by peripheral blood derived T lymphocyte- or T cell clone-mediated tumor ... TNK cells (NKG2D+ CD8+ or CD4+ T lymphocytes) in the control of human tumors.. *Maccalli C ...
title = "Immunoelectron-microscopic study of CD4- and CD8- positive lymphocytes from healthy donors seropositive for human T- ... T1 - Immunoelectron-microscopic study of CD4- and CD8- positive lymphocytes from healthy donors seropositive for human T- ... Immunoelectron-microscopic study of CD4- and CD8- positive lymphocytes from healthy donors seropositive for human T- ... Immunoelectron-microscopic study of CD4- and CD8- positive lymphocytes from healthy donors seropositive for human T- ...
Cell viability is an important factor in achieving positive Th17 differentiation. This can be confirmed through cell counting ... Following separation, CD4+CD25+ (B) and CD4+CD25- (C) fractions were stained to assess purity of CD4+CD25+ and CD4+CD25- T ... Figure 7 presents data from enriched CD4+CD25- T lymphocytes incubated under control or Th17-inducing conditions. CD4+CD25- T ... Isolate CD4+CD25- T cells using the CD4+CD25+ Regulatory T cell Isolation Kit and Miltenyi autoMACS Pro Separator. CD4+CD25- ...
A study of oral candidal carriage and cd4 t-lymphocyte count in hiv positive patients and antifungal susceptibility of isolated ... Asymptomatic oral Candidal colonization is not related to CD4 T- lymphocyte count. Antifungal drug sensitivity must be done. ... There is no association between asymptomatic Candidal colonization on tongue and palate with decreasing CD4 T lymphocyte count ... individuals and to investigate the relationship of asymptomatic Candidal colonization of oral cavity and CD4 T-lymphocyte count ...
Can Improve the Immune Systems of HIV-Positive Patients Who Are Also Participating in ACTG 328 ... Lymphocytes Interleukin-2 Drug Therapy, Combination AIDS Vaccines CD4 Lymphocyte Count Cell Division HIV Core Protein p24 Anti- ... Remune has been reported to increase lymphocyte proliferative responses to HIV antigens in patients with high CD4 cell counts. ... A Study to Test If Giving Remune (an HIV Vaccine) Can Improve the Immune Systems of HIV-Positive Patients Who Are Also ... summary of An International Study to Evaluate Recombinant Interleukin-2 in HIV Positive Patients Taking Anti ... CD4 Lymphocyte Count Disease Progression Follow-Up Studies Anti-HIV Agents Additional relevant MeSH terms: Infection ... HIV positive * Have a CD4 cell count of 300 cells/mm3 or more within 45 days of study entry * Are on combination anti-HIV ... Preservation of immune function by direct expansion of CD4 lymphocytes with rIL-2 could represent a significant additional ...
Immunologically, most neoplastic lymphocytes show an aberrant CD4-positive phenotype with clonal rearrangement of T-cell ... A subcutaneous delta-positive T-cell lymphoma that produces interferon gamma. N Engl J Med. 1991 Oct 10. 325(15):1078-81. [ ... CD4-CD8-"Double-negative" cutaneous T-cell lymphomas share common histologic features and an aggressive clinical course. Am J ... Hydroa vacciniforme-like primary cutaneous CD8-positive T-cell lymphoma. Br J Dermatol. 2002 Sep. 147(3):587-91. [Medline]. ...
Yes atypical lymphocytes reflect the size and shape of lymphocytes as they can be seen under the microscope. They are often ... I have been positive for almost 12 years and i have a really good numbers whit no meds. Cd4 42%, 1400 cels, mi questions are 1 ... Yes atypical lymphocytes reflect the size and shape of lymphocytes as they can be seen under the microscope. They are often ... is normal for a chronic hiv infection to have atipical lymphocytes (betewn 1-2%) 2. is normal to have more lymphocytes than the ...
Scattered positive lymphocytes. CD4. T cell subset. Neoplastic cells Negative. CD57/Leu 7. T subset/NK. Scattered positive ... The patient is a 46-year-old HIV-positive man with a history of substance abuse who presented with a destructive palate lesion ...
CD4+CD28null T cells are present in increased numbers in the peripheral blood of patients with acute coronary syndrome (ACS) ... CD4 Lymphocyte Count. CD4-Positive T-Lymphocytes / immunology*, metabolism. Cell Separation. Chaperonin 60 / blood, immunology* ... CD4+CD28null cells from 12 of 21 patients with ACS reacted with hHSP60. No response was detected to HCMV, C pneumoniae, or ox- ... BACKGROUND: CD4+CD28null T cells are present in increased numbers in the peripheral blood of patients with acute coronary ...
To describe predictors of pregnancy and changes in pregnancy incidence among HIV-positive women accessing HIV clinical care. ... CD4 Lymphocyte Count. Cohort Studies. Female. Great Britain / epidemiology. HIV Seropositivity / epidemiology*. Humans. ... as were women with CD4 cell count less than 200 cells/μl compared with CD4 cell count 200-350 cells/μl [aRR 0.65 (0.55-0.77), P ... HIV-positive women with, or planning, a pregnancy require a high level of care and this is likely to continue and increase as ...
T-Lymphocytes, Helper-Inducer. *Receptors, Chemokine. *CD4-Positive T-Lymphocytes. *TNF. *Cell Movement ... Intratumoral CD4(+)PD-1(high) T cells have a TFH cell phenotype, express CXCR5, secrete IL-21 and are BCL-6 positive with no ... Functionally, CD4(+)PD-1(high) T cells actively supported B-cell growth, while CD4(+)PD-1(low) T cells displayed a reduced ... The goal of our study was to functionally characterize intratumoral CD4(pos) T cells. We showed that CXCR5(hi)ICOS(hi)CD4(pos) ...
Percentages of lymphocytes in total nucleated cells (A) and frequency of CD4-positive CD25-positive Foxp3-positive T cells in ... The percentage of CD4-positive CD25-positive Foxp3-positive T cells present in total CD4-positive T cells was determined by ... The expression of CCR4 (A) and CCR8 (B) on CD4-positive CD25-positive T cells and/or CD4-positive CD25-negative T cells in ... CD4-positive T cells are dominant, and the proportion of CD8-positive T cells is significantly lower than that of CD4-positive ...
... was found to be a nodular lymphocyte predominant Hodgkin lymphoma of the thyroid. So far, thyroid involvement by this variant ... extensive background of CD4+ T-lymphocytes (CD4, 40x); 8: intermingled scattered large "popcorn cells" could be observed (HE, ... Reed-Sternberg cells are identified in more than half of NLPHL cases; however, these tend to be scarce, positive for CD20, and ... Nodular Lymphocyte Predominant Hodgkin Lymphoma of the Thyroid. Carlos Tavares Bello. ,1 João Cassis. ,2 Helder Simões. ,3 and ...
  • Remune has been reported to increase lymphocyte proliferative responses to HIV antigens in patients with high CD4 cell counts. (
  • In this study, patients with moderately advanced HIV disease who have already received 52 weeks of either HAART or HAART plus IL-2 are vaccinated with Remune and a control recall immunogen, tetanus toxoid (TT), to evaluate whether these patients can develop new CD4 T-cell and CD8 T-cell responses to HIV-related antigens. (
  • 6-9 The objective of the present study was to investigate whether any of these antigens act as targets for the CD4 + CD28 null cells. (
  • Cohen CJ, Hellinger JA, Day J, Salitsky N, Shevitz A, Zackin R, DeGruttola V. Lack of effect of cimetidine on lymphocyte subsets in patients infected with human immunodeficiency virus type 1. (
  • The purpose of this observational study is to characterize which immune system cells hide the latent reservoir of HIV by counting the number of latent HIV in different subsets of CD4 cells. (
  • CD4-cell subsets, cellular anti-HIV factors, and cellular drug transporters will be observed to determine which resting memory cells hide latent HIV and to determine the mechanisms responsible for the persistence of the latent HIV reservoir. (
  • Flow cytometry was done to determine T lymphocyte subsets in cell pellets of pleural effusion. (
  • Also, recent reports have shown that several subsets of regulatory T (Treg) cells are involved in controlling autoreactive lymphocytes. (
  • ThPOK continues to repress genes of the CD8 lineage in mature CD4(+) T cells, even as they differentiate into effector helper T cell subsets. (
  • Values indicate percent positivity ( h ) Frequency of CD107 expressing CD4 + splenocytes or TCRγδ + -, CD8αα + -, CD8αβ + -, CD8α − - and CD8α + CD4 + IEL subsets after anti-TCRβ stimulation. (
  • Nonparametric two tailed Mann-Whiteny test was used for statistics ( i ) % cytotoxicity of respective lymphocyte subsets as measured by LDH release assay. (
  • Subsets of peripheral blood lymphocytes were analysed in 31 patients. (
  • Lymphopenia and the depletion of T lymphocyte subsets may be associated with disease activity. (
  • A) Purified subsets of splenocytes and intestinal intraepithelial lymphocytes as indicated were assessed for PLZF mRNA expression by qRT-PCR. (
  • The earliest T-cell progenitors are identified within the CD4 − CD8 − double-negative (DN) subset, which can be subdivided into four subsets based on the expression of CD44 and CD25 ( 22 ). (
  • Numbers of mature TCR(high)/CD4(-)8(+) thymocytes, and also their TCR(high)/CD4(+)8(+) precursors were decreased, as were levels of CD8 expression on all thymocyte subsets investigated. (
  • However, due to the effect of drugs on mother-to-child transmission of AIDS may lead to some changes in the main biochemical indicators of mother-to-child, there is no systematic analysis of the viral load, T lymphocyte subsets and major biochemical indicators of HIV/AIDS pregnant women before and after maternal-to-child transmission. (
  • In this study, the viral load, T lymphocyte subsets and major biochemical indicators of HIV/AIDS pregnant women before and after maternal-infant blockade were dynamically analyzed. (
  • Macrophages and T lymphocytes demonstrated a marked expression of HLA-DR antigen. (
  • In contrast, recruitment of macrophages was delayed with an increase of MAC3-positive staining and F4/80 mRNA expression after 10 weeks of HFD, suggesting a dissociation of macrophage invasion into adipose tissue and IR initiation. (
  • Most macrophages were HLA-DR-positive, reflecting activation through IFNγ, a cytokine released from CD4-positive lymphocytes. (
  • The mycobacterial manipulation of macrophages is counteracted by inflammatory T lymphocytes that activate macrophages through IFN-γ-mediated signaling and exert direct antimycobacterial effector functions through the release of cytolytic granules containing the effector molecules perforin, granzyme B, and, most importantly, granulysin ( 5 ). (
  • Abstract Atherosclerotic lesions contain substantial numbers of activated T lymphocytes in addition to monocytes/macrophages. (
  • 1 Studies by Hansson and coworkers 2 3 have demonstrated that substantial numbers of T lymphocytes, as well as monocytes/macrophages, are present in arterial intima at various stages of atherogenesis. (
  • Efficiency of CD4 depletion was monitored by flow cytometry. (
  • Animals were sacrificed at day 24 after injection with encephalitogenic lymphocytes, and spinal cord inflammation was assessed by flow cytometry. (
  • The CD4+ TCR Vβ repertoire was analysed by flow cytometry in three groups of participants: a) fifteen newly diagnosed children with T1DM (mean age: 9.2 ± 4.78 years old), b) nine newly diagnosed children with SLE, positive for ANA and anti-dsDNA, prior to treatment (mean age: 12.8 ±1.76 years old) and c) 31 healthy age-matched controls (mean age: 6.58 ± 3.65 years old), all of Hellenic origin. (
  • Serum myocardial autoantibodies against beta1-adrenoceptor, alpha-myosin heavy chain, M2-muscarinic receptor and adenine-nucleotide translocator were tested, and inflammatory cytokines and high sensitivity C-reaction protein were measured and lymphocyte subclass was assayed by flow cytometry. (
  • To investigate the specific cell types which may respond to Barodon, two-color fluorescence flow cytometry was used with monoclonal antibodies (mAbs) of different isotypes that reacted with lymphocytes from peripheral blood and lymphoid tissues from treated feeder pigs. (
  • However, only occasional objective clinical responses have been reported suggesting the necessity of CD4(+) T-cell help and possibly antibodies for the induction of an effective anti-tumor immunity in vivo. (
  • Lymphocytes that matures into a plasma cell to create antibodies. (
  • Lymphocytes that secrete antibodies. (
  • The ratio of serum pathogen antibodies positive against Coxsackie virus-B, cytomegalovirus, Mycoplasma pneumoniae and Chlamydia pneumoniae were all markedly higher in patients. (
  • beta(1)-Adrenoceptor antibodies induce positive inotropic response in isolated cardiomyocytes. (
  • Interestingly, a positive correlation was observed between increasing age and CD4 + CD25 + T-cell frequency in both subject groups. (
  • There was no difference between type 1 diabetic subjects of recent-onset versus those with established disease in terms of their CD4 + CD25 + or CD4 + CD25 +Bright T-cell frequency. (
  • In terms of type 1 diabetes, one report ( 22 ) suggested decreased CD4 + CD25 + T-cell frequencies in human type 1 diabetes, findings similar to a second study investigating subjects with autoimmune polyglandular syndrome type 2 ( 23 ). (
  • We found that the degree of infiltration by CD25 + and intratumoral OX40 + lymphocytes showed a tendency to decrease in thicker melanomas. (
  • For both activation markers studied, high peritumoral densities were associated with longer survival by univariate analysis ( P = 0.0028 and P = 0.0255 for CD25 and OX40, respectively), whereas peritumoral OX40 + lymphocyte infiltration had an impact on survival also in multivariate analysis ( P = 0.035). (
  • The results suggest that the presence of lymphocytes expressing the T-cell activation markers CD25 or OX40 shows correlation with tumor progression as well as with patients' survival in cutaneous malignant melanoma. (
  • In a previous study ( 13 ), we showed that cytotoxic T-lymphocyte (CTL) responses to HPV type 16 (HPV-16) E6 and E7 proteins appear to be important in the prevention of SIL in that responses to both E6 and E7 proteins were more commonly found in HPV-16-positive women without SIL than in HPV-16-positive women with SIL. (
  • Recent evidence has suggested that plasma membrane sphingolipids and cholesterol spontaneously coalesce into raft-like microdomains and that specific proteins, including CD4 and some other T-cell signaling molecules, sequester into these rafts. (
  • We conclude that HIV-1 initially binds to CD4 in a raft domain and that its secondary associations with CXCR4 require shifts of proteins and associated lipids away from their preferred lipid microenvironments. (
  • The majority of ALCL are associated with the aberrant expression of anaplastic lymphoma kinase (ALK) fusion proteins and constitute the tumor entity ALK-positive ALCL ( 1 ). (
  • Moreover, NKG2D and TCR triggering was also observed by peripheral blood derived T lymphocyte- or T cell clone-mediated tumor recognition, both in melanoma and colorectal cancer (CRC) patients. (
  • This corresponds with an expansion of GM-CSF producing T lymphocytes in the peripheral blood of patients with SpA compared to controls. (
  • In this study, we provide evidence that lysophosphatidylcholine (lyso-PC), a polar phospholipid component increased in atherogenic lipoproteins and atherosclerotic lesions, can upregulate gene expression and secretion of heparin-binding epidermal growth factor-like growth factor (HB-EGF) in cultured T lymphocytes isolated from human peripheral blood. (
  • The primary cellular receptor for HIV is CD4, but this molecule is insufficient to permit viral fusion. (
  • Immunologically, most neoplastic lymphocytes show an aberrant CD4-positive phenotype with clonal rearrangement of T-cell receptor genes. (
  • This cytokine receptor binds to B-lymphocyte chemoattractant (BLC), and is involved in B-cell migration into B-cell follicles of spleen and Peyer patches. (
  • Indeed, Wu et al demonstrated the presence of CD3-positive T-lymphocytes in human adipose tissue and describe the expression of RANTES, a T-cell specific chemokine, and its respective receptor CCR5 in visceral adipose tissue of morbidly obese patients. (
  • The interaction between BTLA, short for B and T Lymphocyte Attenuator, an inhibitory receptor whose extracellular domain belongs to the immunoglobulin superfamily, and herpesvirus-entry mediator (HVEM), a co-stimulatory tumour-necrosis factor receptor, is unique in that it is the only receptor-ligand interaction that directly links these two families of receptors. (
  • Effects of lyso-PC on T lymphocytes appear to be selective and specific, since lyso-PC also increases interleukin (IL)-2 receptor expression but does not affect mRNA levels for IL-2 or IL-4. (
  • The invention provides methods for identifying agents which modulate the interaction of a chemokine receptor of previously unknown function, Burkitt's Lymphoma Receptor 1 (BLR1), with its ligand, B Lymphocyte Chemoattractant (BLC). (
  • As thymocytes move through the thymus, from triple negatives to single positives, they produce a T-cell antigen receptor (αβTCR) on their cell surface (Fig. 1 ). (
  • In these cell types, HIV-1 entry is mediated by the binding of envelope glycoproteins (gp120 and gp41, Env) to the receptor CD4 and a coreceptor, principally CCR5 or CXCR4, depending on the viral strain (R5 or X4, respectively). (
  • This functional dichotomy is controlled by key transcription factors, including the helper T cell master regulator ThPOK, which suppresses the cytolytic program in major histocompatibility complex (MHC) class II-restricted CD4(+) thymocytes. (
  • Conversely, transgenic expression of PLZF induced CD4(+) thymocytes to acquire effector differentiation and migrate to nonlymphoid tissues. (
  • Immature thymocytes, both triple negatives (αβTCR − CD4 − CD8 − ) and triple positives (αβTCR + CD4 + CD8 + ), participate in intimate cortical lymphoepithelial complexes ( 7 , 14 , 16 , 48 ). (
  • Recent studies by Blotnick et al 6 have revealed that T lymphocytes in atherosclerotic lesions produce smooth muscle growth factors, including HB-EGF, indicating that T cell-derived smooth muscle mitogens, in concert with other cytokines, may modulate fibroproliferative processes in the vessel wall. (
  • This unexpected plasticity resulted in the post-thymic termination of the helper T cell program and the functional differentiation of distinct MHC class II-restricted CD4(+) cytotoxic T lymphocytes. (
  • Ridge, J. P., Di Rosa, F. & Matzinger, P. A conditioned dendritic cell can be a temporal bridge between a CD4 + T-helper and a T-killer cell. (
  • CD4-positive T helper lymphocytes can be. (
  • Immunohistochemical staining of human adipose tissue revealed the presence of mainly CD4-positive lymphocytes as well as macrophage infiltration. (
  • 5 Furthermore, the role of adipose T-lymphocytes as early contributors of obesity-mediated IR and their relationship to adipose tissue macrophage invasion has not yet been studied. (
  • Inflammation during arteriosclerotic lesion development is also characterized by endothelial cell activation as well as monocyte/macrophage and lymphocyte infiltration. (
  • Further investigation of these differences is needed using other types of markers, such as those for chemokine receptors, and other methods to clearly determine the differences between the two types of lymphocytes in fine structure and how these relate to their functions. (
  • Immune checkpoints are receptors on the membrane of T-lymphocytes that can regulate their immune response. (
  • The date of first reporting and the level of first CD4 counts were recorded. (
  • To observe time-associated trends at weeks 4, 8, 12, and 16 in the change of CD4 counts for patients taking cimetidine for the full 16 weeks. (
  • CD4 counts and total lymphocyte count? (
  • Why Do You Use CD4 Counts? (
  • CD4 cell counts tell you how many. (
  • The objectives of this study were to assess the occurrence of cryptosporidiosis in HIV-infected individuals and its relationship with diarrhea, rural or urban zone origin, CD4 + and CD8 + T cell counts, HIV plasmatic viral load, and antiretroviral treatment. (
  • Patients without determined HIV plasmatic viral load or CD4 + and CD8 + T lymphocyte counts at least three months before or after feces sampling were excluded. (
  • Furthermore, therapeutic efficacy in this setting was found to depend on the CD8 + , but not the CD4 + T cell subset, making this experimental system a highly relevant model for CTL-mediated immunotherapy of human melanoma. (
  • Secretion of CTL-recruiting chemokines in the infected tissue depends on CD4 T-cell help. (
  • The phenotype of the inflammatory cell background infiltrate, along with the neoplastic cell morphological and immunophenotypical features, subdivides HL in 2 subgroups: classical and nodular lymphocyte predominant HL. (
  • Cutaneous T-cell lymphoma (CTCL) (see the image below) is a group of lymphoproliferative disorders characterized by localization of neoplastic T lymphocytes to the skin. (
  • A new class of highly antigenic, MHC-II-restricted mycobacterial lipopeptides that are recognized by CD4-positive T lymphocytes of Mycobacterium tuberculosis -infected humans has recently been described. (
  • GM-CSF is emerging as a cytokine that marks out pathogenic T lymphocytes. (
  • Novel triple cytokine capture was used to purify GM-CSF producing lymphocytes to high purity and RNA sequencing used to interrogate their transcriptional profile. (
  • We here compared the effect of GCS-100 with that of LacNAc on the cytotoxicity and cytokine secretion by CD8 + and CD4 + human TIL on ex vivo stimulation, and tested the therapeutic potential of GCS-100 in a murine tumor model. (
  • ABSTRACT: We report the clinical observation of an HIV-positive/AIDS patient with bilateral macular hemorrhage, which resulted in the identification of severe thrombocytopenia. (
  • Pleomorphic infiltration of small/large lymphocytes is observed diffusely infiltrating the dermis. (
  • Methods and Results- In a mouse model of obesity-mediated IR, high-fat diet (HFD) induced IR already after 5 weeks, which was associated with a marked T-lymphocyte infiltration in visceral adipose tissue. (
  • A recent study in mice reported mainly CD8-positive lymphocyte infiltration in hypoxic areas within the adipose tissue. (
  • Methods This retrospective study reviewed clinical records of 883 positive patients, who reported for treatment at the Suntreso Hospital for the first time within January 2010 to December 2011. (
  • Further study is needed to determine the causes for late presenting at the HIV clinic and address them, since this may account for high mortality among HIV positive patients accessing care. (
  • To determine the change in CD4 count after 4 and 8 weeks in HIV-infected patients treated with cimetidine compared to placebo. (
  • To establish a safety record for cimetidine use in HIV-positive patients. (
  • The purpose of this study is to see if it is effective to give HIV positive patients recombinant interleukin-2 (rIL-2) in addition to anti-HIV therapy. (
  • Anti-HIV therapy has been very successful in treating HIV positive patients and in keeping viral load (level of HIV in the blood) low. (
  • However, anti-HIV drugs cannot completely rid the body of the virus, and the immune system is never completely restored in HIV positive patients. (
  • In patients with type 2 diabetes, lymphocyte content in adipose tissue biopsies significantly correlated with waist circumference, a marker of IR. (
  • I read that HIV positive patients have increased 'double negative T lymphocyte' count. (
  • Using an IFN-γ ELISPOT assay, we identified two ALK-derived DRB1-restricted 24-mer promiscuous peptides, ALK1 278-301 and ALK2 233-256 , as being immunogenic in six ALK-positive ALCL patients but not in two ALK-negative ALCL patients or five normal subjects. (
  • This first report of a CD4 + Th response to ALK provides valuable information for developing future immunotherapeutic options for ALK-positive ALCL patients who fail to respond well to conventional therapies. (
  • Evidence confirming ALK as a tumor-associated antigen has been obtained from studies reporting the presence and persistence not only of an antibody response to ALK ( 4 - 6 ) but also of ALK-specific CTLs in patients with ALK-positive ALCL ( 6 , 7 ). (
  • We provide here the first description of a CD4 + Th response to ALK in ALK-positive ALCL patients. (
  • Six ALK-positive ALCL (patients 1-6) and two ALK-negative ALCL (patients 7 and 8), diagnosed according to the WHO classification ( 2 ), and five normal control subjects (normals 1-5) were studied. (
  • Patients were divided into groups according to CD4 + T lymphocyte count and use of potent antiretroviral treatment. (
  • These patients showed a positive response to exercise ECG stress testing, and all had ≥50% diameter stenosis in at least one major coronary artery at catheterization. (
  • This study investigates the effectiveness and tolerability of switching to a darunavir/cobicistat (DRV/c)-based antiretroviral regimen from a ritonavir-boosted protease inhibitor (PI/r)-based regimen in virologically suppressed HIV-positive patients. (
  • In stable HIV-1 positive virologically suppressed patients, the switch to DRV/c-based ART was beneficial in terms of low rates of virological failure and adverse events due to its high tolerability and improvement in triglycerides. (
  • The current treatment of HIV-positive patients requires lifelong administration of combination antiretroviral (ARV) drugs, which is extremely effective and well tolerated, but several factors may decrease its long-term efficacy. (
  • In patients with advanced cancer, tumors progress despite the presence of tumor-infiltrating lymphocytes (TIL). (
  • CD4 + TCR Vβ abnormalities (± 3SD of controls) were observed mainly in SLE patients. (
  • Statistical analysis revealed that the CD4 + Vβ4 chain was significantly increased in patients with T1DM (p (
  • Five patients (33%) presented no abnormalities in all CD4 + Vβ chains values when compared to controls (Table 3, Figure 2). (
  • The safety and efficacy of T reg -depleted donor lymphocyte infusion was studied in 17 adult patients with malignancy relapse after hematopoietic stem cell transplantation. (
  • Two of the 17 patients developed graft-versus-host disease after their first T reg -depleted donor lymphocyte infusion and experienced a long-term remission of their malignancy. (
  • Four of the 15 patients who did not respond after a first T reg -depleted donor lymphocyte infusion received a second T reg -depleted donor lymphocyte infusion combined with lymphodepleting chemotherapy aimed to also eliminate recipient T reg s. (
  • These results suggest that T reg -depleted donor lymphocyte infusion is a safe, feasible approach that induces graft-versus-host or graft-versus-tumor effects in alloreactivity-resistant patients. (
  • In patients not responding to this approach, the combination of chemotherapy-induced lymphodepletion of the recipient synergizes with the effect of T reg -depleted donor lymphocyte infusion. (
  • Mice homozygous for this targeted mutation display many of the characteristics of ataxia telangiectasia, including growth retardation, neurologic dysfunction, infertility, defects in T lymphocyte maturation, and extreme sensitivity to gamma-irradiation. (
  • The CD70 levels in mice are transiently up-regulated during lymphocyte activation, making it difficult to track its expression on DCs ( 8 , 9 ). (
  • Co-expression of CD4 and β2-AR was observed in spleens of both intact and CIA mice. (
  • Jennings, S. R., Bonneau, R. H., Smith, P. M., Wolcott, R. M. & Chervenak, R. CD4-positive T lymphocytes are required for the generation of the primary but not the secondary CD8-positive cytolytic T lymphocyte response to herpes simplex virus in C57BL/6 mice. (
  • The study determined the CD4 lymphocytes count levels of HIV positive patient at first presentation at STI/HIV Clinic at Suntreso Government Hospital in Kumasi, Ghana. (
  • Objectives: To detect the prevalence of asymptomatic Candidal colonization among HIV positive and Healthy individuals and to investigate the relationship of asymptomatic Candidal colonization of oral cavity and CD4 T-lymphocyte count and to assess antifungal drug susceptibility for Candida species by Fluconazole and Voriconazole in vitro. (
  • There is no association between asymptomatic Candidal colonization on tongue and palate with decreasing CD4 T lymphocyte count statistically (P=0.3454, P=0.7279). (
  • Asymptomatic oral Candidal colonization is not related to CD4 T- lymphocyte count. (
  • For irrational reasons I went for a CD4/CD8 count after 5 months from the encounter. (
  • She has never done cd4 count neither has she taken any antiretroviral drug but she has been to the hospital on several occasions in crisis and lab results have always indicated a total wbc of. (
  • What Factors Influence a CD4 Cell Count? (
  • The number of oocysts in all samples was small, independent of CD4 + T lymphocyte count, HIV plasma viral load, and presence of diarrhea. (
  • 0.05) with changing CD4 + lymphocyte count. (
  • CD4 Lymphocyte Count" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (
  • This graph shows the total number of publications written about "CD4 Lymphocyte Count" by people in this website by year, and whether "CD4 Lymphocyte Count" was a major or minor topic of these publications. (
  • Below are the most recent publications written about "CD4 Lymphocyte Count" by people in Profiles. (
  • T lymphocytes were separated by direct positive panning on anti-CD3 monoclonal antibody-coated flasks (MicroCELLector, Applied Immune Sciences) according to the manufacturer's instructions. (
  • These data indicate that electrolyte solution administration to stressed calves may be beneficial by altering lymphocyte populations and antibody concentrations, besides the rehydration benefit. (
  • Patient F had tested negative for HIV antibody in October 1988 (when patient E tested seropositive) and December 1988 but tested positive in December 1990. (
  • Patient G is a young man who contacted CDC after he tested positive for HIV antibody. (
  • The rate of change did not significantly differ according to age group, antiretroviral therapy use, CD4 group or ethnicity. (
  • In several tumor types, the presence of T-cell infiltrates, which may contain tumor-specific lymphocytes, seems to correlate with better prognosis ( 5 - 7 ). (
  • Conclusions: High prevalence of Candidal colonization found among HIV positive individuals. (
  • Homing of B lymphocytes into specialized microenvironments within secondary lymphoid tissues is essential for normal immune function, yet the molecular cues guiding this cellular traffic are not well defined. (
  • 1993. Decrease of CD4-positive T lymphocytes in workers exposed to benzidine and beta-naphthylamine. (
  • Its frequency increases with the decrease in CD4 T lymphocytes and the passage to the AIDS stage. (
  • Furthermore, stimulation of CD4 endocytosis by activation of protein kinase C is preceded by CD4 emigration from rafts ( 34 ). (
  • Lymphocyte-activation protein 3 belongs to Ig superfamily and contains 4 extracellular Ig-like domains. (
  • CD4 + TCR Vβ repertoire usage (values %) in T1DM children resembles the one observed in healthy children with the exception of Vβ4 subpopulation. (
  • Multiple CD4 + and CD8 + T-cell epitopes were identified from both A27 and B5, using overlapping 15-mer peptides. (
  • Background Immunological, genetic and therapeutic studies have implicated T lymphocytes in the pathogenesis of Spondyloarthritis (SpA). (
  • 0.001) compared to controls.CD4 + Vβ4 and CD4 + Vβ16 chains could be possibly involved in the cascade of events precipitating the pathogenesis of T1DM and SLE in children, respectively. (
  • CD4 + Vβ4 and CD4 + Vβ16 chains could be possibly involved in the cascade of events precipitating the pathogenesis of T1DM and SLE in children, respectively. (
  • Moreover, binding of purified monomeric gp120 envelope glycoproteins from strains of HIV-1 that use this coreceptor did not stimulate detectable redistributions of CD4 or CXCR4 between their separate membrane domains. (