Lymphocyte Activation: 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.Lymphocytes: 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.T-Lymphocytes: 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.B-Lymphocytes: 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.Concanavalin A: 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.Antigens, CD: 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.Lymphocyte Subsets: A classification of lymphocytes based on structurally or functionally different populations of cells.Phytohemagglutinins: 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.Interleukin-2: A soluble substance elaborated by antigen- or mitogen-stimulated T-LYMPHOCYTES which induces DNA synthesis in naive lymphocytes.Lymphocyte Count: The number of LYMPHOCYTES per unit volume of BLOOD.Antigens, CD3: 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).Cells, Cultured: 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.Mitogens: 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)Spleen: An encapsulated lymphatic organ through which venous blood filters.Antigens, Differentiation, T-Lymphocyte: 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.Lymphocyte Culture Test, Mixed: 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.CD4-Positive T-Lymphocytes: 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.Receptors, Interleukin-2: 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.Receptors, Antigen, T-Cell: 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.Flow Cytometry: 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.Jurkat Cells: A CELL LINE derived from human T-CELL LEUKEMIA and used to determine the mechanism of differential susceptibility to anti-cancer drugs and radiation.T-Lymphocyte Subsets: A classification of T-lymphocytes, especially into helper/inducer, suppressor/effector, and cytotoxic subsets, based on structurally or functionally different populations of cells.T-Lymphocytes, Cytotoxic: 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.Mice, Inbred C57BLMice, Inbred BALB CAntibodies, Monoclonal: Antibodies produced by a single clone of cells.CD8-Positive T-Lymphocytes: 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.Cytotoxicity, Immunologic: 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.Receptors, Antigen, B-Cell: 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.Antigens, Surface: 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.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Antigens, CD2: 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.Immunoglobulins: 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.Signal Transduction: 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.Lectins: 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.Interferon-gamma: 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.Killer Cells, Natural: 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.Lymphocytes, Tumor-Infiltrating: 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.Leukocyte Count: 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.Lymph Nodes: They are oval or bean shaped bodies (1 - 30 mm in diameter) located along the lymphatic system.Cytokines: 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.Molecular Sequence Data: 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.Immunity, Cellular: 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.Receptors, Immunologic: 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.Immunophenotyping: 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.Lymphocyte Function-Associated Antigen-1: 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.Cyclosporins: A group of closely related cyclic undecapeptides from the fungi Trichoderma polysporum and Cylindocarpon lucidum. They have some antineoplastic and antifungal action and significant immunosuppressive effects. Cyclosporins have been proposed as adjuvants in tissue and organ transplantation to suppress graft rejection.Antigens, CD45: 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.Leukocytes, Mononuclear: 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.Lymphocyte Transfusion: The transfer of lymphocytes from a donor to a recipient or reinfusion to the donor.Mice, Knockout: 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.Membrane Glycoproteins: Glycoproteins found on the membrane or surface of cells.ThymidineIsoantigens: Antigens that exist in alternative (allelic) forms in a single species. When an isoantigen is encountered by species members who lack it, an immune response is induced. Typical isoantigens are the BLOOD GROUP ANTIGENS.Immune Tolerance: 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.Antigens: Substances that are recognized by the immune system and induce an immune reaction.NFATC Transcription Factors: A family of transcription factors characterized by the presence of highly conserved calcineurin- and DNA-binding domains. NFAT proteins are activated in the CYTOPLASM by the calcium-dependent phosphatase CALCINEURIN. They transduce calcium signals to the nucleus where they can interact with TRANSCRIPTION FACTOR AP-1 or NF-KAPPA B and initiate GENETIC TRANSCRIPTION of GENES involved in CELL DIFFERENTIATION and development. NFAT proteins stimulate T-CELL activation through the induction of IMMEDIATE-EARLY GENES such as INTERLEUKIN-2.Antigen-Presenting Cells: 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.Cell Division: The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.Immunologic Capping: An energy dependent process following the crosslinking of B CELL ANTIGEN RECEPTORS by multivalent ligands (bivalent anti-antibodies, LECTINS or ANTIGENS), on the B-cell surface. The crosslinked ligand-antigen receptor complexes collect in patches which flow to and aggregate at one pole of the cell to form a large mass - the cap. The caps may then be endocytosed or shed into the environment.Antigens, CD4: 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.Receptors, Antigen: Molecules on the surface of B- and T-lymphocytes that recognize and combine with specific antigens.Distemper Virus, Canine: A species of MORBILLIVIRUS causing distemper in dogs, wolves, foxes, raccoons, and ferrets. Pinnipeds have also been known to contract Canine distemper virus from contact with domestic dogs.Amino Acid Sequence: 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.Mice, Inbred Strains: 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.Monocytes: 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.Pokeweed Mitogens: 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.Measles virus: The type species of MORBILLIVIRUS and the cause of the highly infectious human disease MEASLES, which affects mostly children.Cell SeparationAutoimmunity: Process whereby the immune system reacts against the body's own tissues. Autoimmunity may produce or be caused by AUTOIMMUNE DISEASES.Antigens, Differentiation: 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.Lymphoid Tissue: 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.Antigens, CD28: 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.Immunoglobulin M: 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.T-Lymphocytes, Helper-Inducer: 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.Ionomycin: A divalent calcium ionophore that is widely used as a tool to investigate the role of intracellular calcium in cellular processes.Dendritic Cells: 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).RNA, Messenger: 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.Lectins, C-Type: 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.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).CARD Signaling Adaptor Proteins: A family of intracellular signaling adaptor proteins that contain caspase activation and recruitment domains. Proteins that contain this domain play a role in APOPTOSIS-related signal transduction by associating with other CARD domain-containing members and in activating INITIATOR CASPASES that contain CARD domains within their N-terminal pro-domain region.T-Lymphocytes, Regulatory: 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.Macrophages: 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.)Receptors, Cell Surface: Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.CD4 Lymphocyte Count: The number of CD4-POSITIVE T-LYMPHOCYTES per unit volume of BLOOD. Determination requires the use of a fluorescence-activated flow cytometer.HLA-DR Antigens: 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.Lymphocyte Specific Protein Tyrosine Kinase p56(lck): 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.Cell Adhesion: Adherence of cells to surfaces or to other cells.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Lymphocyte Depletion: 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.Clone 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)Apoptosis: 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.Immunoglobulin G: The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.Calendula: A plant genus of the family ASTERACEAE. Members contain CAROTENOIDS, essential oils (OILS, VOLATILE), flavonoids, mucilage, SAPONINS, and STEROLS. The plants are used both topically and internally. The common name of Marigold is also used for TAGETES.Receptor-CD3 Complex, Antigen, T-Cell: 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.Antibody Formation: The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.Interleukin-4: 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.Histocompatibility Antigens Class II: 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.Kinetics: The rate dynamics in chemical or physical systems.Dose-Response Relationship, Immunologic: A specific immune response elicited by a specific dose of an immunologically active substance or cell in an organism, tissue, or cell.Receptors, Lymphocyte Homing: 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.Lymphoproliferative Disorders: Disorders characterized by proliferation of lymphoid tissue, general or unspecified.Autoimmune Diseases: Disorders that are characterized by the production of antibodies that react with host tissues or immune effector cells that are autoreactive to endogenous peptides.Lymphocyte Cooperation: T-cell enhancement of the B-cell response to thymic-dependent antigens.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Tetradecanoylphorbol Acetate: A phorbol ester found in CROTON OIL with very effective tumor promoting activity. It stimulates the synthesis of both DNA and RNA.Mice, Inbred C3HRosette Formation: 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.Mice, Inbred CBAMice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Antigens, CD19: Differentiation antigens expressed on B-lymphocytes and B-cell precursors. They are involved in regulation of B-cell proliferation.Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Immunosuppressive Agents: Agents that suppress immune function by one of several mechanisms of action. Classical cytotoxic immunosuppressants act by inhibiting DNA synthesis. Others may act through activation of T-CELLS or by inhibiting the activation of HELPER CELLS. While immunosuppression has been brought about in the past primarily to prevent rejection of transplanted organs, new applications involving mediation of the effects of INTERLEUKINS and other CYTOKINES are emerging.L-Selectin: Cell adhesion molecule and CD antigen that serves as a homing receptor for lymphocytes to lymph node high endothelial venules.Gene Expression Regulation: 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.Immunologic Deficiency Syndromes: Syndromes in which there is a deficiency or defect in the mechanisms of immunity, either cellular or humoral.Thymus Gland: 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.Interleukin-16: A cytokine produced by activated T-LYMPHOCYTES that stimulates the migration of CD4-POSITIVE LYMPHOCYTES and monocytes. It has been reported to suppress HIV replication.Cell Communication: 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.Cysteamine: A mercaptoethylamine compound that is endogenously derived from the COENZYME A degradative pathway. The fact that cysteamine is readily transported into LYSOSOMES where it reacts with CYSTINE to form cysteine-cysteamine disulfide and CYSTEINE has led to its use in CYSTINE DEPLETING AGENTS for the treatment of CYSTINOSIS.Immunologic Memory: 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.Cytotoxicity Tests, Immunologic: The demonstration of the cytotoxic effect on a target cell of a lymphocyte, a mediator released by a sensitized lymphocyte, an antibody, or complement.B-Lymphocyte Subsets: A classification of B-lymphocytes based on structurally or functionally different populations of cells.Fluorescent Antibody Technique: 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.Down-Regulation: A negative 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.Antigens, CD95: 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.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Antibody-Producing Cells: Cells of the lymphoid series that can react with antigen to produce specific cell products called antibodies. Various cell subpopulations, often B-lymphocytes, can be defined, based on the different classes of immunoglobulins that they synthesize.Antigens, Differentiation, B-Lymphocyte: Membrane antigens associated with maturation stages of B-lymphocytes, often expressed in tumors of B-cell origin.Cell Count: The number of CELLS of a specific kind, usually measured per unit volume or area of sample.Tumor Cells, Cultured: 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.Antigens, CD46: 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.Cell Adhesion Molecules: Surface ligands, usually glycoproteins, that mediate cell-to-cell adhesion. Their functions include the assembly and interconnection of various vertebrate systems, as well as maintenance of tissue integration, wound healing, morphogenic movements, cellular migrations, and metastasis.Immunosuppression: 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.Antibodies: Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Immunoglobulin D: An immunoglobulin which accounts for less than 1% of plasma immunoglobulin. It is found on the membrane of many circulating B LYMPHOCYTES.Lupus Erythematosus, Systemic: A chronic, relapsing, inflammatory, and often febrile multisystemic disorder of connective tissue, characterized principally by involvement of the skin, joints, kidneys, and serosal membranes. It is of unknown etiology, but is thought to represent a failure of the regulatory mechanisms of the autoimmune system. The disease is marked by a wide range of system dysfunctions, an elevated erythrocyte sedimentation rate, and the formation of LE cells in the blood or bone marrow.Antibodies, Anti-Idiotypic: Antibodies which react with the individual structural determinants (idiotopes) on the variable region of other antibodies.Cell Movement: The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.Phosphorylation: The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.Hybridomas: Cells artificially created by fusion of activated lymphocytes with neoplastic cells. The resulting hybrid cells are cloned and produce pure MONOCLONAL ANTIBODIES or T-cell products, identical to those produced by the immunologically competent parent cell.Adjuvants, Immunologic: Substances that augment, stimulate, activate, potentiate, or modulate the immune response at either the cellular or humoral level. The classical agents (Freund's adjuvant, BCG, Corynebacterium parvum, et al.) contain bacterial antigens. Some are endogenous (e.g., histamine, interferon, transfer factor, tuftsin, interleukin-1). Their mode of action is either non-specific, resulting in increased immune responsiveness to a wide variety of antigens, or antigen-specific, i.e., affecting a restricted type of immune response to a narrow group of antigens. The therapeutic efficacy of many biological response modifiers is related to their antigen-specific immunoadjuvanticity.Distemper: A name for several highly contagious viral diseases of animals, especially canine distemper. In dogs, it is caused by the canine distemper virus (DISTEMPER VIRUS, CANINE). It is characterized by a diphasic fever, leukopenia, gastrointestinal and respiratory inflammation and sometimes, neurologic complications. In cats it is known as FELINE PANLEUKOPENIA.Antigens, CD30: 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.Receptors, Virus: Specific molecular components of the cell capable of recognizing and interacting with a virus, and which, after binding it, are capable of generating some signal that initiates the chain of events leading to the biological response.Tumor Necrosis Factor-alpha: 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.Leukemia, Lymphoid: Leukemia associated with HYPERPLASIA of the lymphoid tissues and increased numbers of circulating malignant LYMPHOCYTES and lymphoblasts.Receptors, Tumor Necrosis Factor, Member 14: A novel member of the tumor-necrosis factor receptor family that can also mediate HERPES SIMPLEX VIRUS TYPE 1 entry into cells. It has specificity for TUMOR NECROSIS FACTOR LIGAND SUPERFAMILY MEMBER 14 and the homotrimeric form of LYMPHOTOXIN-ALPHA. The receptor is abundantly expressed on T-LYMPHOCYTES and may play a role in regulating lymphocyte activation. Signaling by the activated receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.Cell Proliferation: All of the processes involved in increasing CELL NUMBER including CELL DIVISION.Immune Adherence Reaction: 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.Transfection: 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.Adrenergic Antagonists: Drugs that bind to but do not activate ADRENERGIC RECEPTORS. Adrenergic antagonists block the actions of the endogenous adrenergic transmitters EPINEPHRINE and NOREPINEPHRINE.Ligands: A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)CTLA-4 Antigen: 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.Up-Regulation: 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.Lymphocytes, Null: A class of lymphocytes characterized by the lack of surface markers specific for either T or B lymphocytes.Cyclosporine: A cyclic undecapeptide from an extract of soil fungi. It is a powerful immunosupressant with a specific action on T-lymphocytes. It is used for the prophylaxis of graft rejection in organ and tissue transplantation. (From Martindale, The Extra Pharmacopoeia, 30th ed).Models, Immunological: Theoretical representations that simulate the behavior or activity of immune system, processes, or phenomena. They include the use of mathematical equations, computers, and other electrical equipment.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Cell Line, Transformed: Eukaryotic cell line obtained in a quiescent or stationary phase which undergoes conversion to a state of unregulated growth in culture, resembling an in vitro tumor. It occurs spontaneously or through interaction with viruses, oncogenes, radiation, or drugs/chemicals.Antigen Presentation: 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)Immunoconjugates: Combinations of diagnostic or therapeutic substances linked with specific immune substances such as IMMUNOGLOBULINS; MONOCLONAL ANTIBODIES; or ANTIGENS. Often the diagnostic or therapeutic substance is a radionuclide. These conjugates are useful tools for specific targeting of DRUGS and RADIOISOTOPES in the CHEMOTHERAPY and RADIOIMMUNOTHERAPY of certain cancers.Glycoproteins: Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.NF-kappa B: Ubiquitous, inducible, nuclear transcriptional activator that binds to enhancer elements in many different cell types and is activated by pathogenic stimuli. The NF-kappa B complex is a heterodimer composed of two DNA-binding subunits: NF-kappa B1 and relA.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Antigens, CD27: A member of the tumor necrosis factor receptor superfamily found on most T-LYMPHOCYTES. Activation of the receptor by CD70 ANTIGEN results in the increased proliferation of CD4-POSITIVE T-LYMPHOCYTES and CD8-POSITIVE T-LYMPHOCYTES. Signaling by the activated receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.Antigens, CD40: 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.Th1 Cells: 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.Epitopes, T-Lymphocyte: 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.Mice, Inbred DBAAdoptive Transfer: 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).HIV-1: The type species of LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte.Antigens, CD38: 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.Interphase: The interval between two successive CELL DIVISIONS during which the CHROMOSOMES are not individually distinguishable. It is composed of the G phases (G1 PHASE; G0 PHASE; G2 PHASE) and S PHASE (when DNA replication occurs).CD4-CD8 Ratio: 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.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Interleukin-1: A soluble factor produced by MONOCYTES; MACROPHAGES, and other cells which activates T-lymphocytes and potentiates their response to mitogens or antigens. Interleukin-1 is a general term refers to either of the two distinct proteins, INTERLEUKIN-1ALPHA and INTERLEUKIN-1BETA. The biological effects of IL-1 include the ability to replace macrophage requirements for T-cell activation.Palatine Tonsil: 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.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Lymphokines: Soluble protein factors generated by activated lymphocytes that affect other cells, primarily those involved in cellular immunity.CD40 Ligand: 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.Cell Survival: The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.Superantigens: Microbial antigens that have in common an extremely potent activating effect on T-cells that bear a specific variable region. Superantigens cross-link the variable region with class II MHC proteins regardless of the peptide binding in the T-cell receptor's pocket. The result is a transient expansion and subsequent death and anergy of the T-cells with the appropriate variable regions.Enzyme-Linked Immunosorbent Assay: An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.Reverse Transcriptase Polymerase Chain Reaction: A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.Coculture Techniques: 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.Epitopes: Sites on an antigen that interact with specific antibodies.Recombinant Fusion Proteins: Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.Antigens, CD8: 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.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Th2 Cells: Subset of helper-inducer T-lymphocytes which synthesize and secrete the interleukins IL-4, IL-5, IL-6, and IL-10. These cytokines influence B-cell development and antibody production as well as augmenting humoral responses.Calcimycin: An ionophorous, polyether antibiotic from Streptomyces chartreusensis. It binds and transports CALCIUM and other divalent cations across membranes and uncouples oxidative phosphorylation while inhibiting ATPase of rat liver mitochondria. The substance is used mostly as a biochemical tool to study the role of divalent cations in various biological systems.Lipopolysaccharides: Lipid-containing polysaccharides which are endotoxins and important group-specific antigens. They are often derived from the cell wall of gram-negative bacteria and induce immunoglobulin secretion. The lipopolysaccharide molecule consists of three parts: LIPID A, core polysaccharide, and O-specific chains (O ANTIGENS). When derived from Escherichia coli, lipopolysaccharides serve as polyclonal B-cell mitogens commonly used in laboratory immunology. (From Dorland, 28th ed)Thoracic Duct: The largest lymphatic vessel that passes through the chest and drains into the SUBCLAVIAN VEIN.Intracellular Signaling Peptides and Proteins: Proteins and peptides that are involved in SIGNAL TRANSDUCTION within the cell. Included here are peptides and proteins that regulate the activity of TRANSCRIPTION FACTORS and cellular processes in response to signals from CELL SURFACE RECEPTORS. Intracellular signaling peptide and proteins may be part of an enzymatic signaling cascade or act through binding to and modifying the action of other signaling factors.Biological Markers: Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.Protein-Tyrosine Kinases: Protein kinases that catalyze the PHOSPHORYLATION of TYROSINE residues in proteins with ATP or other nucleotides as phosphate donors.Intercellular Adhesion Molecule-1: A cell-surface ligand involved in leukocyte adhesion and inflammation. Its production is induced by gamma-interferon and it is required for neutrophil migration into inflamed tissue.DNA-Binding Proteins: Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.

Lymphocyte proliferation inhibitory factor (PIF) in alcoholic liver disease. (1/28979)

Lymphocyte proliferation inhibitory factor (PIF) was determined in the supernatants of PHA-stimulated lymphocytes from patients with alcoholic liver disease. PIF was assayed by determining inhibition of DNA synthesis in WI-38 human lung fibroblasts. A two-fold greater inhibition in thymidine incorporation into DNA by lung fibroblasts was observed in supernatants of PHA stimulated lymphocytes from patients with alcoholic hepatitis or active Laennec's cirrhosis as compared with that found in control subjects or patients with fatty liver. It is suggested that decreased liver cell regeneration seen in some patients with alcoholic hepatitis may be due to increased elaboration of PIF.  (+info)

JNK2 is required for efficient T-cell activation and apoptosis but not for normal lymphocyte development. (2/28979)

BACKGROUND: The Jun N-terminal kinase (JNK) signaling pathway has been implicated in cell proliferation and apoptosis, but its function seems to depend on the cell type and inducing signal. In T cells, JNK has been implicated in both antigen-induced activation and apoptosis. RESULTS: We generated mice lacking the JNK2 isozymes. The mutant mice were healthy and fertile but defective in peripheral T-cell activation induced by antibody to the CD3 component of the T-cell receptor (TCR) complex - proliferation and production of interleukin-2 (IL-2), IL-4 and interferon-gamma (IFN-gamma) were reduced. The proliferation defect was restored by exogenous IL-2. B-cell activation was normal in the absence of JNK2. Activation-induced peripheral T-cell apoptosis was comparable between mutant and wild-type mice, but immature (CD4(+) CD8(+)) thymocytes lacking JNK2 were resistant to apoptosis induced by administration of anti-CD3 antibody in vivo. The lack of JNK2 also resulted in partial resistance of thymocytes to anti-CD3 antibody in vitro, but had little or no effect on apoptosis induced by anti-Fas antibody, dexamethasone or ultraviolet-C (UVC) radiation. CONCLUSIONS: JNK2 is essential for efficient activation of peripheral T cells but not B cells. Peripheral T-cell activation is probably required indirectly for induction of thymocyte apoptosis resulting from administration of anti-CD3 antibody in vivo. JNK2 functions in a cell-type-specific and stimulus-dependent manner, being required for apoptosis of immature thymocytes induced by anti-CD3 antibody but not for apoptosis induced by anti-Fas antibody, UVC or dexamethasone. JNK2 is not required for activation-induced cell death of mature T cells.  (+info)

Tyrosine phosphorylation and complex formation of Cbl-b upon T cell receptor stimulation. (3/28979)

Cbl-b, a mammalian homolog of Cbl, consists of an N-terminal region (Cbl-b-N) highly homologous to oncogenic v-Cbl, a Ring finger, and a C-terminal region containing multiple proline-rich stretches and potential tyrosine phosphorylation sites. In the present study, we demonstrate that upon engagement of the T cell receptor (TCR), endogenous Cbl-b becomes rapidly tyrosine-phosphorylated. In heterogeneous COS-1 cells, Cbl-b was phosphorylated on tyrosine residues by both Syk- (Syk/Zap-70) and Src- (Fyn/Lck) family kinases, with Syk kinase inducing the most prominent effect. Syk associates and phosphorylates Cbl-b in Jurkat T cells. A Tyr-316 Cbl-binding site in Syk was required for the association with and for the maximal tyrosine phosphorylation of Cbl-b. Mutation at a loss-of-function site (Gly-298) in Cbl-b-N disrupts its interaction with Syk. Cbl-b constitutively binds Grb2 and becomes associated with Crk-L upon TCR stimulation. The Grb2- and the Crk-L-binding regions were mapped to the C-terminus of Cbl-b. The Crk-L-binding sites were further determined to be Y655DVP and Y709KIP, with the latter being the primary binding site. Taken together, these results implicate that Cbl-b is involved in TCR-mediated intracellular signaling pathways.  (+info)

Vascular endothelial growth factor activates nuclear factor of activated T cells in human endothelial cells: a role for tissue factor gene expression. (4/28979)

Vascular endothelial growth factor (VEGF) is a potent angiogenic inducer that stimulates the expression of tissue factor (TF), the major cellular initiator of blood coagulation. Here we show that signaling triggered by VEGF induced DNA-binding and transcriptional activities of nuclear factor of activated T cells (NFAT) and AP-1 in human umbilical vein endothelial cells (HUVECs). VEGF also induced TF mRNA expression and gene promoter activation by a cyclosporin A (CsA)-sensitive mechanism. As in lymphoid cells, NFAT was dephosphorylated and translocated to the nucleus upon activation of HUVECs, and these processes were blocked by CsA. NFAT was involved in the VEGF-mediated TF promoter activation as evidenced by cotransfection experiments with a dominant negative version of NFAT and site-directed mutagenesis of a newly identified NFAT site within the TF promoter that overlaps with a previously identified kappaB-like site. Strikingly, this site bound exclusively NFAT not only from nuclear extracts of HUVECs activated by VEGF, a stimulus that failed to induce NF-kappaB-binding activity, but also from extracts of cells activated with phorbol esters and calcium ionophore, a combination of stimuli that triggered the simultaneous activation of NFAT and NF-kappaB. These results implicate NFAT in the regulation of endothelial genes by physiological means and shed light on the mechanisms that switch on the gene expression program induced by VEGF and those regulating TF gene expression.  (+info)

Activation-dependent transcriptional regulation of the human Fas promoter requires NF-kappaB p50-p65 recruitment. (5/28979)

Fas (CD95) and Fas ligand (CD95L) are an interacting receptor-ligand pair required for immune homeostasis. Lymphocyte activation results in the upregulation of Fas expression and the acquisition of sensitivity to FasL-mediated apoptosis. Although Fas upregulation is central to the preservation of immunologic tolerance, little is known about the molecular machinery underlying this process. To investigate the events involved in activation-induced Fas upregulation, we have examined mRNA accumulation, fas promoter activity, and protein expression in the Jurkat T-cell line treated with phorbol myristate acetate and ionomycin (P/I), pharmacological mimics of T-cell receptor activation. Although resting Jurkat cells express Fas, Fas mRNA was induced approximately 10-fold in 2 h upon P/I stimulation. Using sequential deletion mutants of the human fas promoter in transient transfection assays, we identified a 47-bp sequence (positions -306 to -260 relative to the ATG) required for activation-driven fas upregulation. Sequence analysis revealed the presence of a previously unrecognized composite binding site for both the Sp1 and NF-kappaB transcription factors at positions -295 to -286. Electrophoretic mobility shift assay (EMSA) and supershift analyses of this region documented constitutive binding of Sp1 in unactivated nuclear extracts and inducible binding of p50-p65 NF-kappaB heterodimers after P/I activation. Sp1 and NF-kappaB transcription factor binding was shown to be mutually exclusive by EMSA displacement studies with purified recombinant Sp1 and recombinant p50. The functional contribution of the kappaB-Sp1 composite site in P/I-inducible fas promoter activation was verified by using kappaB-Sp1 concatamers (-295 to -286) in a thymidine kinase promoter-driven reporter construct and native promoter constructs in Jurkat cells overexpressing IkappaB-alpha. Site-directed mutagenesis of the critical guanine nucleotides in the kappaB-Sp1 element documented the essential role of this site in activation-dependent fas promoter induction.  (+info)

Crystal structure of an MHC class I presented glycopeptide that generates carbohydrate-specific CTL. (6/28979)

T cell receptor (TCR) recognition of nonpeptidic and modified peptide antigens has been recently uncovered but is still poorly understood. Immunization with an H-2Kb-restricted glycopeptide RGY8-6H-Gal2 generates a population of cytotoxic T cells that express both alpha/beta TCR, specific for glycopeptide, and gamma/delta TCR, specific for the disaccharide, even on glycolipids. The crystal structure of Kb/RGY8-6H-Gal2 now demonstrates that the peptide and H-2Kb structures are unaffected by the peptide glycosylation, but the central region of the putative TCR binding site is dominated by the extensive exposure of the tethered carbohydrate. These features of the Kb/RGY8-6H-Gal2 structure are consistent with the individual ligand binding preferences identified for the alpha/beta and gamma/delta TCRs and thus explain the generation of a carbohydrate-specific T cell response.  (+info)

Thymic selection by a single MHC/peptide ligand: autoreactive T cells are low-affinity cells. (7/28979)

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)

RFLAT-1: a new zinc finger transcription factor that activates RANTES gene expression in T lymphocytes. (8/28979)

RANTES (Regulated upon Activation, Normal T cell Expressed and Secreted) is a chemoattractant cytokine (chemokine) important in the generation of inflammatory infiltrate and human immunodeficiency virus entry into immune cells. RANTES is expressed late (3-5 days) after activation in T lymphocytes. Using expression cloning, we identified the first "late" T lymphocyte associated transcription factor and named it "RANTES Factor of Late Activated T Lymphocytes-1" (RFLAT-1). RFLAT-1 is a novel, phosphorylated, zinc finger transcription factor that is expressed in T cells 3 days after activation, coincident with RANTES expression. While Rel proteins play the dominant role in RANTES gene expression in fibroblasts, RFLAT-1 is a strong transactivator for RANTES in T cells.  (+info)

TY - JOUR. T1 - Antigen-pulsed neutrophils bearing Ia antigens can induce T lymphocyte proliferative response to the syngeneic or semisyngeneic antigen-primed T lymphocytes. AU - Okuda, K.. AU - Tani, K.. AU - Ishigatsubo, Y.. AU - Yokota, S.. AU - David, C. S.. PY - 1980. Y1 - 1980. N2 - Antigen-pulsed neutrophils from mouse peritoneal cavities displayed a remarkable level of lymphocyte proliferative activities to antigen-primed T lymphocytes. Genetic mapping studies demonstrated that compatibility at the I-A, as well as I-E/C, subregions of the major histocompatibility complex (MHC) was essential for effective presentation of the lysozyme antigen. These antigen-presenting activities were remarkably inhibited by anti-Ia sera. Inhibition tests revealed that neutrophil immune-associated (Ia) antigens seem to be essential for antigen presentation during the initial 8 hr. Elimination studies of antigen-pulsed neutrophils with alloantisera plus complement revealed these antigen-presenting ...
Results Exogenously added IL-7 did not activate B cells directly, in line with the absence of surface IL-7R. However, in the presence of T cells, IL-7 activated both T and B cells (Ki67+ CD4 cells from 1.1±0.2% to 14.4±3.7%, p,0.01 and Ki67+ B cells from 1.9±0.3% to 4.1±0.9%, p,0.05). TLR7A induced B cell activation, as measured by increased proliferation (%Ki67 from 1.2±0.2% to 9.3±1.4%) and up regulation of activation markers on B cells, which was facilitated in the presence of monocytes. TLR7-induced B cell activation in T/B or T/B/monocyte co-cultures was not associated with T cell activation. IL-7 added to TLR7A synergistically increased both B cell (TLR7A vs. IL-7/TLR7A; 9.3±1.4% vs. 33.4±7.3%) and T cell proliferation (IL-7 vs. IL-7/TLR7A; 0.8±0.1% vs. 29.2±5.2%), which for B cells again was further increased by monocytes (TLR7A vs. IL-7/TLR7A; 30.2±8.9% vs. 63.0±8.0%). Similar results were observed for activation marker expression on B cells (CD19, HLA-DR CD25) and on T cells ...
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
by Barbara Stranger, Ye CJ, Feng T, Kwon HK, Raj T, Wilson MT, Asinovski N, McCabe C, Lee MH, Frohlich I, Paik HI, Zaitlen N, Hacohen N, De Jager P, Mathis D, Regev A, Benoist C. T lymphocyte activation by antigen conditions adaptive immune responses and immunopathologies, but we know little about its variation in humans and its genetic or environmental roots. We analyzed gene expression in CD4(+) T cells during unbiased activation or in T helper 17 (T(H)17) conditions from 348 healthy participants representing European, Asian, and African ancestries. We observed interindividual variability, most marked for cytokine transcripts, with clear biases on the basis of ancestry, and following patterns more complex than simple T(H)1/2/17 partitions. We identified 39 genetic loci specifically associated in cis with activated gene expression. We further fine-mapped and validated a single-base variant that modulates YY1 binding and the activity of an enhancer element controlling the autoimmune-associated ...
DCs are believed to initiate the CD8+ T cell response in the draining LN by providing signals through the TCR and CD28. Beyond this initiation phase, however, the role of DCs and CD28 costimulation during later phases and at the effector site is largely unexplored. Previous studies have suggested that CD8+ T cells responses are programmed during priming and do not require Ag beyond initiation (1-3); however, these conclusions were based on short 3-6 d in vivo expansion or survival of CD8+ T cells (1-3). In these studies, in vitro-activated T cells were transferred in uninfected mice, and it was showed that the cells undergo divisions in the absence of Ag for up to 6 d after transfer into uninfected mice. Our studies show that in the context of a viral infection such as influenza, effector CD8+ T cells fail to fully expand when transferred into uninfected recipients or animals infected with an influenza virus that does not express cognate peptide (Fig. 4B, 4C). Based on the above, it appears that ...
IL-2-regulated genes in PBMCs. Pre-activated, rested human PBMCs were left untreated or restimulated for 4 hr with IL-2, and RNA probes were prepared for hybrid
Sigma-Aldrich offers abstracts and full-text articles by [Nabila Seddiki, Laura Cook, Denise C Hsu, Chansavath Phetsouphanh, Kai Brown, Yin Xu, Stephen J Kerr, David A Cooper, C Mee Ling Munier, Sarah Pett, Jintanat Ananworanich, John Zaunders, Anthony D Kelleher].
Specificity of T lymphocyte activation ... Molecular rearrangements w/synapse formation ... Two different MAP Kinase pathways are involved in receptor signaling ... – A free PowerPoint PPT presentation (displayed as a Flash slide show) on PowerShow.com - id: 229ace-ZTQ4Y
Germain, R N.; Mayer, S V.; and Mescher, M F., "Role of i-region gene products in t cell activation. I. Stimulation of t lymphocyte proliferative responses by subcellular membrane preparations containing ia alloantigens." (1982). Subject Strain Bibliography 1982. 16 ...
Inflammatory reactions are believed to be triggered by innate signals and have a major protective role by recruiting innate immunity cells, favoring lymphocyte activation and differentiation, and thus contributing to the sequestration and elimination of the injurious stimuli. Although certain lymphocyte types such as TH17 cells co-participate in inflammatory reactions, their generation from the naïve pool requires the pre-existence of an inflammatory milieu. In this context, inflammation is always regarded as beginning with an innate response that may be eventually perpetuated and amplified by certain lymphocyte types. In contrast, we here show that even in sterile immunizations or in MyD88 deficient mice, CD8 T cells produce a burst of pro-inflammatory cytokines and chemokines. These functions follow opposite rules to the classic CD8 effector functions since they are generated prior to cell expansion and decline before antigen elimination. As few as 56 CD8+ inflammatory effector cells in a lymph node
Doenhoff, M J.; Janossy, G; Greaves, M F.; Gomer, K J.; and Snajdr, J, "Lymphocyte activation. VI. A re-evaluation of factors affecting the selectivity of polyclonal mitogens for mouse t and b cells." (1974). Subject Strain Bibliography 1974. 1563 ...
T and B lymphocytes tailor their responses to each pathogenic insult as part of the adaptive immune system. During an infection, activation of B cells causes them to proliferate, differentiate, and synthesize a variety of potential antibodies to pathogenic antigens. Immunological responses also activate T cells, inducing them to differentiate into a wide variety of subtypes, including cytotoxic T cells and T helper cells. Cytotoxic T cells recognize and destroy infected cells, and T helper cells communicate with B cells to mediate appropriate immune responses. Dysregulation of B cell or T cell functions can cause immunodeficiencies. Changes in gene expression and epigenetic regulation play a large part in T and B cell activation mechanisms. Understanding these changes may define how precursor lymphocytes decide their fates under specific experimental conditions ...
Initially, a role for the interaction between CD40, expressed on B cells, and gp39 (CD40L), expressed on activated T cells, has been defined in humoral immunity...
Schematic diagram of CD4+ effector T cell activation at the site of M. tuberculosis infection.A. During the chronic stage of infection, A
Study Flashcards On T cell activation and function at Cram.com. Quickly memorize the terms, phrases and much more. Cram.com makes it easy to get the grade you want!
The molecular process of Antigen Processing and Presentation leads to T lymphocyte activation and function to enable CD4 T cells to potentiate the humoral and cellular immune responses, and CD8 T cel…
Interleukin 2 (IL-2) is a pleiotropic cytokine produced primarily by mitogen- or antigen-activated T lymphocytes . Human IL-2 (also known as T-cell…
|p|β-Interleukin I (163-171), human(C|sub|39|/sub|H|sub|64|/sub|N|sub|12|/sub|O|sub|19|/sub|), a peptide with the sequence Val-Gln-Gly-Glu-Glu-Ser-Asn-Asp-Lys, MW= 1005.|strong| |/strong|Interleukins are a group of cytokines (secreted proteins/signaling m
Researchers, using mathematical models, have defined for the first time how powerfully immune cells respond to infection and disease. The team combined laboratory data with mathematical models to clarify how different external signals impact on T cell proliferation.
Learn about the new personal insight questions on the UC application. Tips & strategies on how to prepare strong responses will be shared with you. For more information, contact the Transfer Counseling Center at (310) 434-4210 ...
Sometimes I wish my politically moderate opinions were as sexy as the extreme ones some use to elicit a strong response from people. I just dont share
LEAD: The article, Taking a Scalpel to Health Care Costs (Jan. 8) prompted an unusually strong response from readers. Some of their comments follow. To the Editor:
T lymphocyte proliferation assay according to the free Medical Dictionary. Measures the strength of response of T memory cells|.
Ethanol consumption is associated with impaired immunity. Our data demonstrate that even a single dose of a biologically relevant concentration (25-150 mM) of ethanol can down-regulate antigen-specific T lymphocyte proliferation. In contrast, ethanol augmented mitogen-induced T cell proliferation, suggesting that its inhibitory effect on antigen-specific T cell proliferation was due to its effects on monocytes (m phi s) rather than on T cells. The immunodepressive effects of ethanol on m phi antigen-presenting cell (APC) capacity were manifested whether alcohol treatment was limited to the antigen uptake-processing period only or was present during the entire period of antigen presentation. These inhibitory effects of ethanol were also evident on both the high-antigen-presenting, Fc gamma RI-negative (-31 +/- 17%), and low-antigen-presenting, Fc gamma RI-positive (-42 +/- 15%) m phi subpopulations. Further analysis demonstrated that ethanol inhibits the production of interleukin-1 beta (IL-1 beta) and
TY - JOUR. T1 - Direct effects of HP Acthar Gel® on human B lymphocyte activation in vitro. AU - Olsen, Nancy. AU - Decker, Dima A.. AU - Higgins, Paul. AU - Becker, Patrice M.. AU - McAloose, Carl A.. AU - Benko, Ann L.. AU - Kovacs, William. PY - 2015/10/27. Y1 - 2015/10/27. N2 - Introduction: Both clinical experience and experimental evidence have suggested that Adrenocorticotropic hormone (ACTH) might directly exert immunomodulatory effects not dependent on adrenal steroidogenesis. Methods: The direct effects of H.P. Acthar Gel® (Acthar), a repository preparation containing a porcine ACTH analogue, on human B lymphocyte function were studied in vitro using peripheral blood B cells isolated using anti-CD19 coated magnetic beads and activated by interleukin 4 (IL-4) and CD40 ligand (CD40L). Analysis of expression of messenger RNA (mRNA) encoding activation-induced cytidine deaminase (AICDA) was carried out by quantitative real-time polymerase chain reaction (PCR). Cellular proliferation was ...
Effects of Polysaccharide Extracted from Traditional Chinese Medical Herbs on Lymphocyte Transformation Rate and AI-HI Antibody Titer in Chicks
Effects of Polysaccharide Extracted from Traditional Chinese Medical Herbs on Lymphocyte Transformation Rate and AI-HI Antibody Titer in Chicks
The mixed leucocyte reaction, (MLR), has been applied successfully to peripheral blood leucocytes of the mouse. Before harvest, the leucocytes were mobilized into the peripheral blood by a single intravenous injection of the mice with pertussis vaccine. Mixtures, (50-50), of C57BL/6 and DBA/2 mouse leucocytes were cultured in medium containing low amounts of mouse plasma and supplemented with foetal bovine serum. DNA-synthetic activities at selected times were determined by liquid scintillation counting following pulse labeling of the cell populations with 3H-TdR. DNA synthesis in the mixed cultures attained a maximum value at the 5th to 7th day (7,500 cpm), as contrasted with maximum control values of 200-1000 cpm). Considerable DNA synthesis (1000-2000 cpm), also was observed at zero time, and then declined to low levels (200-300 cpm) at the 18th hour. DNA synthesis did not occur in the mixed leucocyte cultures when the culture medium was supplemented with dog plasma in place of foetal bovine
TY - JOUR. T1 - Investigation of K+ channel expression in human peripheral lymphocytes of healthy donors by means of flow cytometry. AU - Krjukova, J.. AU - Osna, N.. AU - Pilmane, M.. PY - 2000/1/1. Y1 - 2000/1/1. N2 - Evaluation of different types of K+ channel expression was performed in resting and PHA (phytohemagglutinine)-activated human peripheral lymphocytes (HPL) of healthy donors by means of flow cytometry. In resting peripheral lymphocytes, the application of kaliotoxin (a selective blocker for voltage-dependent K+ (K(V)) channels), K(V) resulted in pronounced depolarization of lymphocyte membrane potential, with further promotion in the presence of thapsigargin (compound discharging Ca(i) from endoplasmic reticulum). In activated HPL, the expression of various types of K+ channels was estimated utilizing cell-cycle analysis data. In contrast to the resting cells, kaliotoxin-induced depolarization of membrane potential in PHA-activated lymphocytes of the G0/G1 phase was not enhanced ...
TY - JOUR. T1 - Cyclosporin A inhibits initiation but not progression of human T cell proliferation triggered by phorbol esters and calcium ionophores. AU - Kumagai, N.. AU - Benedict, S. H.. AU - Mills, G. B.. AU - Gelfand, E. W.. PY - 1988/12/1. Y1 - 1988/12/1. N2 - Cyclosporin A (CsA) is a potent inhibitor of T lymphocyte proliferation induced by Ag and mitogens. In an attempt to further delineate the mechanism of action of CsA, we have examined its effects on T cell proliferation induced by the combination of the phorbol ester, phorbol 12,13-dibutyrate (PDB), and the calcium ionophore, ionomycin. T cells were rendered competent as the result of a 30-min initial incubation with both drugs, after which the drugs were washed out. Competence is defined as the ability to subsequently proliferate in response to exogenously added IL-2 or PDB in the second phase of the culture, but not to synthesize IL-2 or proliferative without these additions. Addition of CsA (1 μg/ml) to the cells in the ...
TY - JOUR. T1 - Analysis of the age-related refractoriness of T-lymphocyte reactivity in humans. AU - Bátory, Gabriella. AU - Ónody, Clara. AU - Petrányi, G. Gy. PY - 1981/4. Y1 - 1981/4. N2 - Aged individuals could be divided into two groups according to their T-lymphocyte transformation values. The relationship between the PHA (phytohemagglutinin) stimulation indices and spontaneous thymidine incorporation; the PHA dose-response type distribution and the relative number of resting T lymphocytes was similar to the control group in aged subjects of seemingly intact T lymphocyte transformation values. However, their B cell compartment was found to be reduced. On the other hand, the ratio between the stimulation indices and spontaneous thymidine incorporation values of aged subjects of impaired T lymphocyte reactivity deviated from that of the control group. This group had an increased frequency of subjects giving maximal transformation values at relatively high PHA doses (hyposensitives) at ...
Malaria infection has been shown to induce alterations in immune reactivity. This report describes the effect of serum obtained from Plasmodium falciparum infected patients on in vitro proliferation of human blood mononuclear cells (BMNC) isolated from healthy individuals. Serum obtained before initiation of treatment suppressed the in vitro lymphocyte proliferative response to both Plasmodium-derived antigens and an unrelated antigen (PPD-tuberculin). The suppressive effect was lost if the serum was incubated at 56 degrees C for 30 min, and the effect was not HLA-restricted since the inhibition was seen on both autologous and heterologous BMNC. The degree of suppression was not correlated to the duration of the disease, the degree of parasitemia, or the use of chemoprophylaxis. Sera from 7 patients before and from 3 patients 30 days after initiation of treatment were pooled and fractionated. It was found that the strongest suppressive activity was in the serum fraction containing molecules from ...
Transmembrane signaling of normal human T cells was explored with mAbs directed at TCR, CD2, CD4, CD5, or CD8 antigens and highly purified CD4+ T cells and CD8+ T cells. Our experiments explicitly show that: (a) crosslinkage of TCR with the CD2 antigen, and not independent crosslinking of TCR and of CD2 antigen or crosslinking of either protein with the CD4 or CD8 antigen induces significant proliferation independent of co-stimulatory signals (e.g., accessory cells, recombinant lymphokines, or tumor promoter), (b) F(ab)2 fragments of mAb directed at the TCR and F(ab)2 anti-CD2, crosslinked with F(ab)2 fragments of rabbit anti-mouse IgG, promote the proliferation of highly purified T cells, (c) a prompt and sustained increase in intracellular free Ca2+ concentration results from crosslinkage of TCR with the CD2 antigen, (d) T cell proliferation induced by this novel approach is curtailed by EGTA and by direct or competitive inhibitors of PKC, (e) crosslinkage of TCR with the CD2 antigen ...
NFAT2 null mutant mice die in utero of cardiac failure, precluding analysis of the role of NFAT2 in lymphocyte responses. Only the NFAT2-/-/Rag-1-/- chimeric mice model gave insight into the role of NFAT2 transcription factor in T lymphocyte development, activation and differentiation. As reports are mainly focused on the role of NFAT2 in CD4+ T lymphocytes activation and differentiation, we decided to investigate NFAT2s impact on CD8+ T lymphocytes responses. We report that NFAT2 is phosphorylated and inactive in the cytoplasm of naive CD8+ T cells, and upon TCR stimulation is dephosphorylated and translocated into the nucleus. To study the role of NFAT2 in CD8+ T responses we employed NFAT2fl/flCD4-Cre mice with NFAT2 deletion specifically in T cells. Interestingly, the absence of NFAT2 in T cells resulted in increased percentage of nonconventional innate-like CD8+ T cells. These cells were CD122+, rapid producer of IFN-γ and had characteristics of conventional memory CD8+ T cells. We also observed
ABSTRACT. In this in vitro study, T cell responses induced by breast tumor cell lysate pulsed monocyte-derived DCs were analyzed in terms of proliferation, specific cytotoxicity and cytokine-release in order to use in immunotherapeutic settings. Nylon wool enriched T lymphocytes from 5 patients with breast cancer stimulated in vitro with tumor cell lysate pulsed monocyte-derived DCs and their proliferation response were analyzed by [3H] thymidine uptake test. Specific cytotoxic activity of tumor antigen primed T cells after three rounds weekly stimulation was evaluated by flow cytometry, and interferon-γ (IFN-γ) and interleukin-4 (IL-4) cytokines release assay was carried out 24 hours after last stimulation in the supernatant of primed T cells using commercially available ELISA kits. T cell proliferation assay revealed that tumor cell lysate pulsed DCs could stimulate autologous T cell proliferation response with stimulation indices 4.9 - 30. T cell mediated cytotoxicity assay demonstrated ...
Acute phase samples (9) and post-recovery samples (14) from cases of SJS or TEN to LTG were provided by the RegiSCAR-study group. Controls were persons never exposed to LTG (12), patients exposed without reaction (6), and patients who developed a mild eruption to LTG (6). LTT was performed by measuring 3H-thymidine incorporation after 3 days of incubation with phytohemmaglutinin, LTG (10 μg/mL) or medium. Stimulation index ≥ 2 was considered positive. In 16 cases LTT was redone after depletion of T-reg by fluorescence activated cell sorting. ...
A simple in vitro experimental system was devised to reflect the in vivo generation of a T cell anamnestic response so that T cell differentiation could be examined at the level of lymphokine gene expression. Comparison of neonatal and adult T cells revealed that both populations expressed the genes for interleukin 2 (IL-2) and its receptor, but only adult T cells were capable of transcribing mRNAs for IL-3, IL-4, IL-5, IL-6, interferon gamma, and granulocyte/macrophage colony-stimulating factor. However, neonatal T cells could be induced to undergo functional differentiation in vitro, thereby acquiring the capacity to express the lymphokine gene repertoire characteristic for adult T cells. These data suggest that the T cells generated from neonatal blood by a primary stimulation in vitro are functionally indistinguishable from the T cells in adult blood that presumably have undergone primary stimulation in vivo. Therefore, we propose that the term "memory cell" be applied to those T cells that ...
The close similarity of the reported findings with nicotine on immune function (Caggiula et al., 1992; McAllister et al., 1994) with the results of the studies conducted in our laboratory with morphine led us to further explore the relationship between nicotinic and opioid-induced alterations in immune function. The results (Figs.1-3) with acute systemic morphine, nicotine and epibatidine treatment presented here demonstrated that each of these compounds produce: 1) antinociception, 2) decreased magnitude of peripheral blood lymphocyte proliferation responses to mitogen without altering the sensitivity of the lymphocytes, 3) no alteration of either splenic or thymic proliferation responses, and 4) an elevation of circulating corticosterone levels. Collectively, these results indicate that the effects of systemic morphine are largely mimicked by both nicotine and epibatidine treatment.. Although considerable evidence supports the involvement of a central site of action for systemic morphine on ...
Another test, Lymphocyte transformation test, is available from Pharmasan and others. This test measures a different kind of immune response. It is based on FDA approved, commercially available TB tests. The test measures the innate immune response. An initial response which predates acquired immune responses which lead to antibody production. Immune cells patrolling our blood and tissues have the ability to recognize patterns which shouldnt be there (Pattern Recognition Receptors). Killer T cell lymphocytes are the first line of defense. Killer T cells attack offending antigen (Lyme) and turn on other immune responses including the production of cytokines, modulators of immune regulation. When this reaction occurs it leaves behind permanent T memory cells. These memory cells, when exposed to Lyme antigens react by releasing gamma interferon, a potent cytokine. This reaction can be measured. This test may be considered a complement to other tests, such as the Western Blot test. It is somewhat ...
The experiments described in this thesis document the development of two in vivo models, to investigate the effect of competition for peptide-MHC and factors independent of MHC on T cell proliferation, differentiation, generation of memory cells and affinity maturation. The first model made use of 3 strains of T cell receptor (TCR) transgenic (tg) mice of varying specificity for antigen-MHC class II. To determine the effect of antigen specific and non-specific competition on the early stages of the T cell response, the efficiency with which naïve antigen-specific CD4+ T cells were recruited into an ongoing immune response was investigated. Recruitment into cell division and cytokine production was shown to decrease with an increasing time delay between two cell cohorts of the same specificity, leading to a significant drop in recruitment with a delay of only 24 hours. Injection of additional antigen could partially compensate for this decrease, suggesting that lack of available antigen limited ...
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 ...
The role of CD4 as a coreceptor that promotes initial T cell Ag receptor-mediated activation events is well established. However, the role of CD4 in regulating previously activated T cells and ongoing immune responses is less well understood. In the present study, we have found that CD4 signaling is required for a distinct checkpoint during Th2 effector cell development, which is independent of initial T cell stimulation. Although production of Th2-associated cytokines is significantly diminished in T cells primed under Th2 conditions in the absence of CD4 signaling, initial Th2 development appeared intact as defined by the appropriate induction of IL-4 and GATA-3 transcription. These findings are quite distinct from other studies in itk, SAP, and fyn-deficient mice in which Th2 development was compromised in cells primed under neutral conditions, but was recovered upon the addition of exogenous IL-4 in conjunction with a high potency TCR stimulus (14, 15, 16). In these cases, the defect in Th2 ...
TY - JOUR. T1 - The CD40 ligand expressed by human B cells costimulates B cell responses. AU - Grammer, A. C.. AU - Bergman, M. C.. AU - Miura, Y.. AU - Fujita, K.. AU - Davis, L. S.. AU - Lipsky, P. E.. PY - 1995/1/1. Y1 - 1995/1/1. N2 - The possibility that activated B cells might express a ligand for CD40 that was of functional importance for B cell responses was examined by using highly purified human peripheral blood B cells, as well as a variety of B lymphoblastoid cell lines and hybridomas. Following stimulation with the combination of a calcium ionophore and a phorbol ester, human B cells bound a soluble fusion protein containing the extracellular portion of CD40 and the Fc region of lgG1 (CD40.lg). A variety of B cell lines and hybridomas also bound CD40.1g, either constitutively or after activation. In addition, CD40.Ig specifically immunoprecipitated a 33-kDa glycoprotein from surface 125I-labeled activated B cells. The nucleotide sequence of the coding region of the CD40 ligand mRNA ...
In this report, the Global Lymphocyte Activation Gene 3 Protein Market is valued at USD XX million in 2016 and is expected to reach USD XX million by the e
The CD2 antigen (LFA-2) is a monomeric 50 kDa glycoprotein. It was formerly described as the sheep red blood cell receptor, causing T-cell rosetting, and has been identified as the ligand for CD58 (LFA-3). It is also a receptor for CD48, CD59 and CD15, which binds to the multimeric form of CD2. CD2 is present on the majority of normal human peripheral blood T lymphocytes and a high percentage of NK cells. It is also expressed by all thymocytes ...
Thank you for your interest in spreading the word about Biochemical Society Transactions.. NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. We do not capture any email address.. ...
Here, we reported the identification of a PIP2-derived signaling amplification loop for the initiation of B cell activation (fig. S7). Specifically, we observed that there is a highly dynamic spatial-temporal change of PIP2 within the immunological synapse during B cell activation: PIP2 is efficiently depleted inside the BCR microclusters but is regenerated outside the BCR microclusters. Both events are important for the sustained initiation of B cell activation. Mechanistically, the hydrolysis of PIP2 inside the BCR microclusters induced a positive feedback mechanism for its synthesis outside the BCR microclusters.. The positive feedback nature of the PIP2-derived amplification loop is achieved by the unique Brownian mobility of PIP2 metabolic products. DAG, the product of PIP2 hydrolysis within the BCR microclusters, exhibits high Brownian mobility, which ensures its efficient interaction with DGKζ outside the BCR microclusters. PA, converted from DAG by DGKζ, drastically facilitates the ...
Un metodo per espandere γδ cellule T dalle cellule mononucleate del sangue periferico (PBMC) è descritta. PBMC cellule derivate γδ T...
DREAM is a multifunctional protein able to specifically interact with DNA and/or other proteins to execute defined functions in different cell compartments. In this study, we show that in T lymphocytes DREAM regulates the expression of three cytokine genes, IL‐2, IL‐4 and IFNγ. The proposed repressor mechanism involves recognition and binding to specific DREs located in their promoters. As previously shown for other Ca2+‐activated genes like c‐fos, ICER and AA‐NAT (Carrion et al, 1999; Link et al, 2004), in IL‐2 and IL‐4 promoters DREAM binds to a doublet with one direct and one inverted DRE repeat located downstream from the transcription initiation site and downregulates their activity. In the case of the IFNγ gene, like for the prodynorphin and the fra‐2 promoters, binding of DREAM to a single DRE site downstream from the TATA box is enough to repress transcription (Carrion et al, 1998, 1999; Link et al, 2004). Binding of DREAM or EFmDREAM to DRE sites downstream from the ...
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 ...
Cytokine-induced NK and Cytotoxic T lymphocyte (CTL) activation[edit]. Cytokines play a crucial role in NK cell activation. As ... granular lymphocytes known today as NK cells. The demonstration that density gradient-isolated large granular lymphocytes were ... Natural killer cells, or NK cells, are a type of cytotoxic lymphocyte critical to the innate immune system. The role NK cells ... A functional marker of human non-T lymphocytes". Clinical and Experimental Immunology. 21 (2): 226-35. PMC 1538269. PMID 810282 ...
"Entrez Gene: LAG3 lymphocyte-activation gene 3".. *^ a b c Triebel F, Jitsukawa S, Baixeras E, Roman-Roman S, Genevee C, Viegas ... Lymphocyte-activation gene 3, also known as LAG-3, is a protein which in humans is encoded by the LAG3 gene.[5] LAG3, which was ... "Lymphocyte activation gene-3 (CD223) regulates the size of the expanding T cell population following antigen activation in vivo ... "Maturation and activation of dendritic cells induced by lymphocyte activation gene-3 (CD223)". Journal of Immunology. 168 (8): ...
Lymphocyte. 30%. Small lymphocytes 7-8. Large lymphocytes 12-15. *B cells: releases antibodies and assists activation of T ... Lymphocyte. Main article: Lymphocyte. Lymphocytes are much more common in the lymphatic system than in blood. Lymphocytes are ... lymphocytes) by hematopoietic lineage (cellular differentiation lineage).[6] Lymphocytes can be further classified as T cells, ... Lymphocytes include: *B cells make antibodies that can bind to pathogens, block pathogen invasion, activate the complement ...
Complement activation. Mixed lymphocyte reaction T-cell receptors. Phagocyte function. First to fully describe IgA deficiency. ... 16, 301-310 Versey, J.M.B., Slater, L., Hobbs, J.R. Activation of complement in relation to disease, (1975) J.Clin.Path. 28, ... 6. 38-44 Yamamura, M., Nikbin, B., Hobbs, J.R. Standardisation of the mixed lymphocyte reaction (1976) Journal of Immunological ... 219-317 Foroozanfar, N., Yamamura, M. and Hobbs, J.R. Standardization of lymphocyte transformation to candida immunogen, (1974 ...
The peripheral lymphoid organs are the sites of lymphocyte activation by antigens. Activation leads to clonal expansion and ... Associated organs composed of lymphoid tissue are the sites of lymphocyte production. Lymphocytes are concentrated in the lymph ... the spleen retains the ability to produce lymphocytes. The spleen stores red blood cells and lymphocytes. It can store enough ... The tertiary lymphoid tissue[clarification needed] typically contains far fewer lymphocytes, and assumes an immune role only ...
"Lymphocyte activation antigens. I. A monoclonal antibody, anti-Act I, defines a new late lymphocyte activation antigen". J. ... Although the antibody did not block primary activation of T lymphocytes, it appeared late after activation with a number of ... T lymphocytes originally isolated from blood lymphocytes. The cell lines were created in Dr. Jim T. Kurnick's lab. ... Atul Bhan's group showed that it stained tissue lymphocytes but did not react with non-lymphoid tissues. Although Act-1 had ...
The defect in lymphocyte activation and protective immunity suggested that caspase-8 had additional signaling roles in ... "Pleiotropic defects in lymphocyte activation caused by caspase-8 mutations lead to human immunodeficiency". Nature. 419 (6905 ... B cell activation. • cell surface receptor signaling pathway. • response to lipopolysaccharide. • cellular response to ... natural killer cell activation. • negative regulation of I-kappaB kinase/NF-kappaB signaling. • TRAIL-activated apoptotic ...
"HIV inhibits the early steps of lymphocyte activation, including initiation of inositol phospholipid metabolism". Journal of ... "HIV Gag p17 protein impairs proliferation of normal lymphocytes in vitro". AIDS. 8 (7): 1016-7. doi:10.1097/00002030-199407000- ... "Human immunodeficiency virus proteins induce the inhibitory cAMP/protein kinase A pathway in normal lymphocytes". Proceedings ...
Role in T-lymphocyte activation". Tissue Antigens. 50 (5): 439-48. doi:10.1111/j.1399-0039.1997.tb02898.x. PMID 9389317. Soares ... 1995). "V7, a novel leukocyte surface protein that participates in T cell activation. I. Tissue distribution and functional ... 1995). "V7, a novel leukocyte surface protein that participates in T cell activation. II. Molecular cloning and ...
Activation[edit]. The T lymphocyte activation pathway: T cells contribute to immune defenses in two major ways; some direct and ... 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 ... and lymphocyte activation gene 3 protein (LAG3).[59][60] Soluble molecules such as cytokines IL-10 or TGF-β are also able to ... While in most cases activation is dependent on TCR recognition of antigen, alternative pathways for activation have been ...
"Helper T Cells and Lymphocyte Activation". Chandra, Vivek; Bortnick, Alexandra; Murre, Cornelis (2015-09-01). "AID targeting: ... Class-switching is mediated by the AID (activation-induced cytidine deaminase) enzyme and only occurs after the B cell binds an ... The levels of surface expression of IgD isotype has been associated with differences in B cell activation status but their role ... and activation of complement cascade. As IgM antibodies are expressed early in a B cell response, they are rarely highly ...
The B lymphocyte, in this ready-to-respond form, is known as a "naive B lymphocyte." The naive B lymphocyte expresses both ... Activation of effector cells[edit]. To combat pathogens that replicate outside cells, antibodies bind to pathogens to link them ... Activation of complement[edit]. Antibodies that bind to surface antigens (for example, on bacteria) will attract the first ... Parker D (1993). "T cell-dependent B cell activation". Annu Rev Immunol. 11 (1): 331-360. doi:10.1146/annurev.iy.11.040193. ...
Reif K, Cyster J (2002). "The CDM protein DOCK2 in lymphocyte migration". Trends Cell Biol. 12 (8): 368-73. doi:10.1016/S0962- ... Lu M, Ravichandran KS (2006). "Dock180-ELMO cooperation in Rac activation". Methods Enzymol. 406: 388-402. doi:10.1016/S0076- ...
LMP2A mediates B-lymphocyte survival through constitutive activation of the Ras/PI3K/Akt pathway". Oncogene. 23 (53): 8619-8628 ... Most LMP2 research is focused on LMP2A isoform due to its unique expression in latently infected B lymphocytes in situ. LMP2B ... Two motifs that are centered on Y74 and Y85 are spaced 7 residues apart to form an immunoreceptor tyrosine-based activation ... Viral LMP2A mRNA is frequently detected in peripheral blood B lymphocytes and the protein is often present in tumor biopsies ...
"RNA synthesis and histone acetylation during the course of gene activation in lymphocytes". Proceedings of the National Academy ... activation,[44]. repression[43] activation repression[45] acetylation activation[47] activation[46] activation[46] activation[ ... activation[43] activation[43] activation[43][44] activation[43] activation[43] di-methylation repression[45] repression[45] ... The mechanism for mRNA activation has been found to be the removal of a segment of the 3' end of the mRNA strand, and is ...
Kornfeld H, Cruikshank WW, Pyle SW, Berman JS, Center DM (1988). "Lymphocyte activation by HIV-1 envelope glycoprotein". Nature ... Activation of the receptor increases proliferation of CD8+ effector T cells. IL2RB has been shown to interact with: CISH, HGS, ... "Functional activation of Jak1 and Jak3 by selective association with IL-2 receptor subunits". Science. 266 (5187): 1045-7. doi: ... "The role of interleukin-2 during homeostasis and activation of the immune system". Nat Rev Immunol. 12 (3): 180-190. doi: ...
Okkenhaug K, Vanhaesebroeck B (April 2003). "PI3K in lymphocyte development, differentiation and activation". Nat. Rev. Immunol ... 2004). "Macrophage activation through CCR5- and CXCR4-mediated gp120-elicited signaling pathways". J. Leukoc. Biol. 74 (5): 676 ... Borgatti P, Zauli G, Cantley LC, Capitani S (1998). "Extracellular HIV-1 Tat protein induces a rapid and selective activation ... Deane JA, Fruman DA (2004). "Phosphoinositide 3-kinase: diverse roles in immune cell activation". Annu. Rev. Immunol. 22: 563- ...
Kornfeld H, Cruikshank WW, Pyle SW, Berman JS, Center DM (September 1988). "Lymphocyte activation by HIV-1 envelope ... Lymphocytes expressing the common gamma chain can form functional receptors for these cytokine proteins, which transmit signals ... The common gamma chain partners with other proteins to direct blood-forming cells to form lymphocytes (a type of white blood ... The γc glycoprotein is a member of the type I cytokine receptor family expressed on most lymphocyte (white blood cell) ...
Sharfe N, Dadi HK, O'Shea JJ, Roifman CM (June 1997). "Jak3 activation in human lymphocyte precursor cells". Clinical and ... Activation by IL-2 led to tyrosine phosphorylation-dependent interactions between Jak3 and p52ShcA only at lower concentrations ... Though constitutive activation of Janus kinase 3 (Jak3) leads to different cancers, the mechanism of trans-molecular regulation ... Jak3 expression and activation provide protection against development of CLGI and associated health complications. Studies in ...
Xavier, R., et al., Discs large (Dlg1) complexes in lymphocyte activation. J Cell Biol, 2004. 166(2): p. 173-8. Hanada, T., et ... Such changes may be able to enhance or inhibit the activation of these signaling proteins. An example is the Ste5 scaffold in ... Huang, G.N., et al., NFAT binding and regulation of T cell activation by the cytoplasmic scaffolding Homer proteins. Science, ... Claperon, A. and M. Therrien, KSR and CNK: two scaffolds regulating RAS-mediated RAF activation. Oncogene, 2007. 26(22): p. ...
"The lymphocyte story". New Scientist (1605): 1. Retrieved 2007-09-13. Galdiero, MR; Garlanda, C; Jaillon, S; Marone, G; ... "Modulation of Macrophage Activation State Protects Tissue from Necrosis during Critical Limb Ischemia in Thrombospondin-1- ... Macrophages can be classified on basis of the fundamental function and activation. According to this grouping there are ... David M. Mosser & Justin P. Edwards (December 2008). "Exploring the full spectrum of macrophage activation". Nature Reviews ...
The T-cell receptor, or TCR, is a molecule found on the surface of T cells, or T lymphocytes,[1] that is responsible for ... Associated molecules of the TCR complex involved in T-cell activation[edit]. The essential function of the TCR complex is to ... 2001). Immunobiology: The Immune System in Health and Disease (5th ed.). Chapter 4, The Generation of Lymphocyte Antigen ... Unlike immunoglobulins, however, TCR genes do not undergo somatic hypermutation, and T cells do not express activation-induced ...
"Lymphokines": Non-Antibody Mediators of Cellular Immunity generated by Lymphocyte Activation. Nature, 1969-10, roč. 224, čís. ... BOYLE, J. J.. Macrophage activation in atherosclerosis: pathogenesis and pharmacology of plaque rupture. [s.l.] : [s.n.], 2005 ...
DeFranco, Anthony (2008). "Chapter 8: B Lymphocyte Signaling Mechanisms and Activation". In Paul, William. Fundamental ... Depending on the specific subfamily in question, activation can be highly variable. Activation by either Gαq or Gβγ G-protein ... Members of the Rho GTPase family (e.g., Rac1, Rac2, Rac3, and cdc42) have been implicated in their activation by binding to an ... Binding of its substrate PIP2 to the N-terminal PH domain is highly specific and functions to promote activation of the ...
2004). "Discs large (Dlg1) complexes in lymphocyte activation". J. Cell Biol. 166 (2): 173-8. doi:10.1083/jcb.200309044. PMC ...
Common variable immunodeficiency is thought to be due to a problem in the differentiation from lymphocytes to plasma cells. The ... These T cells bind to the MHC II-antigen molecule and cause activation of the B cell. This is a type of safeguard to the system ... Plasma cells are large lymphocytes with a considerable nucleus-to-cytoplasm ratio and a characteristic appearance on light ... the activation and growth of B cell clones able to secrete antibodies of higher affinity for the antigen. ...
Also, natural infection with varicella zoster virus has been found to stimulate tonsillar lymphocytes better than lymphocytes ... resulting in gene activation, leading to mitotic division, growth and differentiation, migration, or apoptosis. They are ... If the tonsillar lymphocytes became overwhelmed with this persistent stimulation they may be unable to respond to other ... and B-lymphocytes and other immunocompetent cells. The cytokine network represents a very sophisticated and versatile ...
... cytotoxic anti-tumor activity and lymphocyte activation" by Jiménez-Medina E, Garcia-Lora A, Paco L, Algarra I, Collado A, ...
Section I deals with factors that regulate the development and maturation of T cells and B cells and lymphocyte traffic. The ... Lymphocyte Development And Lymphocyte Traffic. * Lymphocyte Development in Neonatal and Adult C-Kit-Deficient (C-Kitw/w) Mice ... Lymphocyte Trafic in Lymphoid Organ Neogenesis Danielle L. Drayton, Kee Chan, Werner Lesslauer, Jason Lee, Mao Yon Ying, Nancy ... The significance of C-kit, Bcl-6, IL-7, and Vav in the development of T and B lymphocytes is discussed. A role of lymphotoxins ...
... rapid progress has been made in the understanding of biochemical pathways for signal transduction in lymphocyte activation. ... B Lymphocyte Activation, Proliferation and Differentiation. * The Activation, Proliferation, and Differentiation of Human B ... Human T Lymphocyte Activation Claudio Milanese, Robert F. Siliciano, Neil E. Richardson, Hsiu-Ching Chang, Andres Alcover, ... Regulation of Proto-Oncogene Expression During T Lymphocyte Activation and Proliferation John C. Reed, Michael B. Prystowsky, ...
Diacylglycerol and protein kinase D localization during T lymphocyte activation.. Spitaler M1, Emslie E, Wood CD, Cantrell D. ... Unstimulated T cells are shown to have a uniform distribution of DAG at the plasma membrane, whereas after T cell activation, a ... reveal the immune synapse as a focal point for DAG and PKD as an immediate and dynamic DAG effector during T cell activation. ...
Mechanisms of Lymphocyte Activation and Immune Regulation IV. Book Subtitle. Cellular Communications. Editors. * Sudhir Gupta ... Mechanisms of Lymphocyte Activation and Immune Regulation IV. Cellular Communications. Editors: Gupta, Sudhir, Waldmann, Thomas ... B-Lymphocyte Lineage-Committed, IL-7 and Stroma Cell- Reactive Progenitors and Precursors, and Their Differentiation to B Cells ... A role of src family phosphotyrosine kinases in T cell activation has been demonstrated and several phosphotyrosine kinase ...
Mechanisms of Lymphocyte Activation and Immune Regulation XI. B Cell Biology. Editors: Gupta, S., Alt, F.W., Cooper, M.D., ... Mechanisms of Lymphocyte Activation and Immune Regulation XI. Book Subtitle. B Cell Biology. Editors. * Sudhir Gupta ... These proceedings highlight recent developments in lymphocyte development, Ig gene rearrangements and somatic hypermutation, ... chromatin structure modification, B lymphocyte signaling and fate, receptor editing, and autoimmunity. ...
The MAGUK family protein CARD11 is essential for lymphocyte activation.. Hara H1, Wada T, Bakal C, Kozieradzki I, Suzuki S, ... Moreover, B cell proliferation and JNK activation were impaired upon stimulation of TLR4 with lipopolysaccharide, indicating ... PKC-mediated proliferation and cytokine production in T and B cells due to a selective defect in JNK and NFkappaB activation. ...
At optimum ratios of mitogen to serum most of the lymphocytes in the culture transform, whereas at higher ratios transformation ... WHEN certain mitogenic agents are added to lymphocytes cultured in serum, the cells are activated to transform and divide1. A ... Inhibition of Lymphocyte Activation at High Ratios of Concanavalin A to Serum depends on Complement. *PETER MILTHORP1. & ... MILTHORP, P., FORSDYKE, D. Inhibition of Lymphocyte Activation at High Ratios of Concanavalin A to Serum depends on Complement ...
Crossing the Threshold of Lymphocyte Activation Message Subject (Your Name) has forwarded a page to you from The Journal of ... Indeed, although the necessity of receptor occupation for lymphocyte activation was a central tenet of clonal selection, even ... the studies highlighted here provided the first definitive demonstration of an affinity threshold for lymphocyte activation. ... Crossing the Threshold of Lymphocyte Activation. Michael P. Cancro. J Immunol May 1, 2005, 174 (9) 5159-5160; DOI: https://doi. ...
Lymphocytes are activated upon antigen (Ag) recognition by their clonotypic surface Ag receptors, TCR in the case of T cells ... Antigen‐induced lymphocyte activation: the two‐signal paradigm. Four major steps take place in lymphocyte activation: Ag ... Lymphocytes: Antigen‐Induced Gene Activation. Abel Suárez‐Fueyo, Instituto de Investigación Hospital, Madrid, Spain Joaquín ... Lymphocyte activation triggers multiple signalling cascades that converge in the cell nucleus to cause significant changes in ...
... Jong-Jin Kim,1 Yun-Ho Hwang,2 Kyung- ... H. J. Park, J. H. Hong, H. J. Kwon et al., "TLR4-mediated activation of mouse macrophages by Korean mistletoe lectin-C (KML-C ... on proliferation and cytokine expression in human peripheral blood mononuclear cells and T-lymphocytes," Archives of Pharmacal ...
Here, we report that lobe A-mediated DOCK2 dimerization is crucial for Rac activation and lymphocyte migration. We found that ... The migratory properties of lymphocytes depend on DOCK2, an atypical Rac activator predominantly expressed in hematopoietic ... Lymphocytes Is the Subject Area "Lymphocytes" applicable to this article? Yes. No. ...
Activation, and Inflammatory DiseasesIn the original article, two clarifications about cited references are necessary.First, ... Lymphocyte Autophagy in Homeostasis, Activation, and Inflammatory Diseases ... Lymphocyte Autophagy in Homeostasis, Activation, and Inflammatory Diseases. by Arbogast, F., and Gros, F. (2018). Front. ... Corrigendum: Lymphocyte Autophagy in Homeostasis, Activation, and Inflammatory Diseases. Florent Arbogast1,2 and Frédéric Gros1 ...
The invention discloses methods for inducing a desired T helper lymphocyte regulated immune response by delivering an immunogen ... One type of lymphocyte is the B lymphocyte (B cell) that targets and indirectly destroys foreign substances by mounting a ... The other type of lymphocyte is the T lymphocyte (T cell) that targets and directly kills foreign substances by mounting a cell ... Cytokines produced by Th1 cells activation are IL-2, IFNγ, IL-12, IL-18. These cytokines are involved in macrophage activation ...
HIV-1-specific CD4+ T lymphocyte turnover and activation increase upon viral rebound. ... HIV-1-specific CD4+ T lymphocyte turnover and activation increase upon viral rebound. ... HIV-specific CD4+ T helper lymphocytes are preferred targets for infection. Although complete interruption of combination ...
The signalling lymphocyte activation molecule family (SLAMF) of cell-surface molecules has been identified as a group of ... receptors that modulates the activation and differentiation of a wide array of cell types involved in both innate and adaptive ...
PLEIOTROPIC EFFECT IN LYMPHOCYTE ACTIVATION CAUSED BY CASPASE-8 MUTATIONS LEAD TO HUMAN IMMUNODEFICIENCY. Kathleen E. Sullivan ... Caspase-8 is now known to have an undefined but integral function in lymphocyte activation and the phenotype of patients with ... In addition to the defect in apoptosis, the authors describe a very significant defect in lymphocyte activation that probably ... PLEIOTROPIC EFFECT IN LYMPHOCYTE ACTIVATION CAUSED BY CASPASE-8 MUTATIONS LEAD TO HUMAN IMMUNODEFICIENCY ...
Phorbol ester treatment inhibits phosphatidylinositol 3-kinase activation by, and association with, CD28, a T-lymphocyte ... Phorbol ester treatment inhibits phosphatidylinositol 3-kinase activation by, and association with, CD28, a T-lymphocyte ... Phorbol ester treatment inhibits phosphatidylinositol 3-kinase activation by, and association with, CD28, a T-lymphocyte ... Phorbol ester treatment inhibits phosphatidylinositol 3-kinase activation by, and association with, CD28, a T-lymphocyte ...
Transferrin receptor bearing cells in rheumatoid arthritis and an in vitro model of lymphocyte activation by Michael Salmon; 1 ... Transferrin receptor bearing cells in rheumatoid arthritis and an in vitro model of lymphocyte activation 1 edition ... Transferrin receptor bearing cells in rheumatoid arthritis and an in vitro model of lymphocyte activation Michael Salmon. ... Transferrin receptor bearing cells in rheumatoid arthritis and an in vitro model of lymphocyte activation ,publication-date = ...
Vibrational spectroscopic changes of B-lymphocytes upon activation. J. Biophoton., 6: 101-109. doi: 10.1002/jbio.201200136 ...
T-lymphocytes ; T-cell ; T-lymphocyte ; arginine methylation ; protein methylation ; proteomics ; heavy methyl SILAC ; WASp ; ... To gain insight into the role of protein arginine methylation in T-lymphocyte activation, the aims of this work were to: 1. ... WASp is essential for T-lymphocyte activation and some initial evidence showed that one of the arginine methylation sites is ... Due to their importance in immune responses and disorders, the molecular mechanisms leading to T-lymphocyte activation have ...
... examined the activation profile of T lymphocytes and the production of cytokines associated with activated T lymphocytes during ... Abstract 5509: Evidence of T lymphocyte activation following sipuleucel-T treatment. Johnna Wesley, Ling-Yu Kuan, Eric Chadwick ... Abstract 5509: Evidence of T lymphocyte activation following sipuleucel-T treatment. Johnna Wesley, Ling-Yu Kuan, Eric Chadwick ... Abstract 5509: Evidence of T lymphocyte activation following sipuleucel-T treatment. Johnna Wesley, Ling-Yu Kuan, Eric Chadwick ...
Buy the Paperback Book Mechanisms of Lymphocyte Activation and Immune Regulation X by Sudhir Gupta at Indigo.ca, Canadas ... Mechanisms of Lymphocyte Activation and Immune Regulation X: Innate Immunity. EditorSudhir Gupta, William E. Paul, Ralph ... Title:Mechanisms of Lymphocyte Activation and Immune Regulation X: Innate ImmunityFormat:PaperbackDimensions:172 pages, 9.25 × ... Customer Reviews of Mechanisms of Lymphocyte Activation and Immune Regulation X: Innate Immunity. ...
  • and changes in gene expression that characterise activated lymphocytes. (els.net)
  • In contrast, the amount of pol II recruited to promoters was essentially the same with or without activation, suggesting that enhanced gene expression in response to LPS+IL-4 is not regulated by pol II recruitment. (cancer.gov)
  • These results suggest that under basal conditions pol II complexes are in closed confirmations and activation promotes complex opening and gene expression. (cancer.gov)
  • In this report, the Global Lymphocyte Activation Gene 3 Protein Market is valued at USD XX million in 2016 and is expected to reach USD XX million by the end of 2022, growing at a CAGR of XX% between 2016 and 2022. (medgadget.com)
  • Stimulation of PLEKHG2 by Gβγ induced serum response element (SRE)-mediated gene transcription via activation of Rac and Cdc42 but not RhoA. (asm.org)
  • We examined whether glucocorticoids could modulate the expression of activation-induced cytidine deaminase (AICDA), the principal regulator of the processes of immunoglobulin gene somatic hypermutation and class switch recombination in B lymphocytes. (elsevier.com)
  • Upregulation of intracellular GSH by incubation with 10 mM NAC for 48 h resulted in diminished Rap1 activation, while depletion of GSH by pre-incubation with 200mM BSO resulted in increased Rap1 activation. (bmj.com)
  • Given the presumed key role for autoreactive lymphocytes in multiple sclerosis (MS), treatment strategies have been developed to ablate lymphocyte activity. (bmj.com)
  • Diacylglycerol and protein kinase D localization during T lymphocyte activation. (nih.gov)
  • The dual specificity phosphatase 2 encodes an enzyme that reverses mitogen activated protein kinase cell activation by dephosphorylation. (eurekamag.com)
  • The degree of activation of soluble cyclic 3',5'-AMP-dependent protein kinase(s) was determined at various times following ConA stimulation. (aspetjournals.org)
  • Separation of the free catalytic subunit from type I and type II protein kinase holoenzyme isozymes via C 6 -aminoalkyl agarose chromatography revealed that only type I protein kinase was activated 4 hr following incubation of lymphocytes with a mitogenic concentration of ConA (10 µg/ml). (aspetjournals.org)
  • The data suggest that while the early activation of type I cyclic AMP-dependent protein kinase may mediate in a positive manner the induction of ornithine decarboxylase and the mitogenic response of lymphocytes to ConA, concomitant activation of type II protein kinase may inhibit this process. (aspetjournals.org)
  • In addition to the increase in phosphotyrosine levels upon activation by TPA, there is a concomitant increase in phosphoserine content due to the activation of protein kinase C. Lipopolysaccharide (LPS) causes translocation of protein kinase C from the cytoplasm to the plasma membrane and as lipid A, the free lipid portion of LPS, activates protein kinase C the possibilty arises that LPS, like TPA, activates protein kinase C directly. (gla.ac.uk)
  • JNK1: a protein kinase stimulated by UV light and Ha-Ras that binds and phosphorylates the c-Jun activation domain. (springermedizin.de)
  • Biosynthesis of glycosaminoglycans by thymic lymphocytes. (elsevier.com)
  • Isolated thymic lymphocytes were labeled with D-[6- 3 H]-glucosamine and 35 SO 4 2- , and the amounts of radioactivity in each family of glycosaminoglycan or other types of saccharides were determined. (elsevier.com)
  • Isolated thymic lymphocytes were labeled with D-[6-3H]-glucosamine and 35SO42-, and the amounts of radioactivity in each family of glycosaminoglycan or other types of saccharides were determined. (elsevier.com)
  • Even though evidence from several systems suggests that proteoglycans or their polysaccharide side chains, the glycosaminoglycans, are important mediators (modulators) of cellular interactions, little is known concerning the biosynthesis or possible functions of these macromolecules in lymphocytes. (elsevier.com)
  • As an initial step in our systematic analyses of the complex arrays of protein saccharides of lymphocytes, the biosynthesis and secretion of glycosaminoglycans by both unstimulated and mitogenically activated lymphocytes have been investigated. (elsevier.com)
  • The purpose of this study was to identify the genes responsible for this lymphocyte inhibitory factor (LIF) activity. (asm.org)
  • Three genes, early growth response factor 1 (EGR-1), dual specificity phosphatase 2, and CD69 (early T-cell activation antigen), showed a 2.0-fold or greater increase in mRNA transcription at four or more of six time points in two studies. (eurekamag.com)
  • Several genes (PKC, n-myc, jun D, and BCL-2) previously reported as overexpressed in CLL lymphocytes were overexpressed in these studies also, but were not altered by TPA treatment. (eurekamag.com)
  • A role of src family phosphotyrosine kinases in T cell activation has been demonstrated and several phosphotyrosine kinase substrates have been identified and their functions characterized. (springer.com)
  • The answer to this riddle emerged from the experiment summarized in Table VI, which showed that as little as a 2-fold molar excess of monovalent ligand could thwart primary B cell activation by multiply substituted hapten carrier complexes. (jimmunol.org)
  • For details on specific aspects of T‐ and B‐cell activation, see text. (els.net)
  • Cantrell D (2003) GTPases and T cell activation. (els.net)
  • Interestingly, such a role for caspases in T cell activation is indirectly supported by several recent observations. (rupress.org)
  • In combined cycloheximid and radioactive labelling approaches it was shown that DUSP6 degradation was impaired, but not fully blocked by ONX 0914 in T cell activation. (uni-konstanz.de)
  • Fig. 8.1: B cell activation. (yourarticlelibrary.com)
  • Cell-to-cell contact between B cell and T H cell provides the second signal required for B cell activation. (yourarticlelibrary.com)
  • Binding of antigen to the surface immunoglobulin's provides the first signal and initiates the B cell activation. (yourarticlelibrary.com)
  • 2. The binding between CD40L molecules (on T cell) with CD40 (on B cell) delivers the second signal for B cell activation. (yourarticlelibrary.com)
  • Furthermore, T-cell activation requires sustained signaling achieved through the establishment of what is known as the immunological synapse, in which peptide-MHC-II complexes form clusters on the APC membrane allow-ing aggregation and clustering of multiple TcR molecules on the opposing T-cell membrane. (brainkart.com)
  • The associated CD3 complex, however, has 10 intracytoplasmic motifs (im-munoreceptor-tyrosine-based activation motifs, ITAMs) that play a key role in the sequence of cell activation. (brainkart.com)
  • similarly, if the activating signal is dominant, then NK cell activation will result. (wikipedia.org)
  • 4) Lymphocyte stimulation results in a rapid and dramatic increase in the relative proportion of both cell-associated and cell-secreted chondroitin 6-sulfates. (elsevier.com)
  • Thus, caspase activation is an early and physiological response in viable, stimulated lymphocytes, and appears to be involved in early steps of lymphocyte activation. (rupress.org)