Antigens: Substances that are recognized by the immune system and induce an immune reaction.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.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.Antigens, Neoplasm: Proteins, glycoprotein, or lipoprotein moieties on surfaces of tumor cells that are usually identified by monoclonal antibodies. Many of these are of either embryonic or viral origin.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).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.Antigens, Bacterial: Substances elaborated by bacteria that have antigenic activity.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.Antigens, CD34: Glycoproteins found on immature hematopoietic cells and endothelial cells. They are the only molecules to date whose expression within the blood system is restricted to a small number of progenitor cells in the bone marrow.Antigens, CD19: Differentiation antigens expressed on B-lymphocytes and B-cell precursors. They are involved in regulation of B-cell proliferation.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.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.Antigens, CD20: Unglycosylated phosphoproteins expressed only on B-cells. They are regulators of transmembrane Ca2+ conductance and thought to play a role in B-cell activation and proliferation.Antigens, Viral: Substances elaborated by viruses that have antigenic activity.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.Antigens, CD44: Acidic sulfated integral membrane glycoproteins expressed in several alternatively spliced and variable glycosylated forms on a wide variety of cell types including mature T-cells, B-cells, medullary thymocytes, granulocytes, macrophages, erythrocytes, and fibroblasts. CD44 antigens are the principle cell surface receptors for hyaluronate and this interaction mediates binding of lymphocytes to high endothelial venules. (From Abbas et al., Cellular and Molecular Immunology, 2d ed, p156)Antigens, CD7: Differentiation antigens expressed on pluripotential hematopoietic cells, most human thymocytes, and a major subset of peripheral blood T-lymphocytes. They have been implicated in integrin-mediated cellular adhesion and as signalling receptors on T-cells.Antigens, CD14: Glycolipid-anchored membrane glycoproteins expressed on cells of the myelomonocyte lineage including monocytes, macrophages, and some granulocytes. They function as receptors for the complex of lipopolysaccharide (LPS) and LPS-binding protein.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.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.Antigens, CD5: Glycoproteins expressed on all mature T-cells, thymocytes, and a subset of mature B-cells. Antibodies specific for CD5 can enhance T-cell receptor-mediated T-cell activation. The B-cell-specific molecule CD72 is a natural ligand for CD5. (From Abbas et al., Cellular and Molecular Immunology, 2d ed, p156)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.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.Antigens, CD1: Glycoproteins expressed on cortical thymocytes and on some dendritic cells and B-cells. Their structure is similar to that of MHC Class I and their function has been postulated as similar also. CD1 antigens are highly specific markers for human LANGERHANS CELLS.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Antigens, CD56: The 140 kDa isoform of NCAM (neural cell adhesion molecule) containing a transmembrane domain and short cytoplasmic tail. It is expressed by all lymphocytes mediating non-MHC restricted cytotoxicity and is present on some neural tissues and tumors.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.ADP-ribosyl Cyclase: A membrane-bound or cytosolic enzyme that catalyzes the synthesis of CYCLIC ADP-RIBOSE (cADPR) from nicotinamide adenine dinucleotide (NAD). This enzyme generally catalyzes the hydrolysis of cADPR to ADP-RIBOSE, as well, and sometimes the synthesis of cyclic ADP-ribose 2' phosphate (2'-P-cADPR) from NADP.Antigens, Differentiation, Myelomonocytic: Surface antigens expressed on myeloid cells of the granulocyte-monocyte-histiocyte series during differentiation. Analysis of their reactivity in normal and malignant myelomonocytic cells is useful in identifying and classifying human leukemias and lymphomas.Antigens, CD80: A costimulatory ligand expressed by ANTIGEN-PRESENTING CELLS that binds to CTLA-4 ANTIGEN with high specificity and to CD28 ANTIGEN with low specificity. The interaction of CD80 with CD28 ANTIGEN provides a costimulatory signal to T-LYMPHOCYTES, while its interaction with CTLA-4 ANTIGEN may play a role in inducing PERIPHERAL TOLERANCE.Antigens, CD53: Tetraspanin proteins found at high levels in cells of the lymphoid-myeloid lineage. CD53 antigens may be involved regulating the differentiation of T-LYMPHOCYTES and the activation of B-LYMPHOCYTES.Antigens, CD24: A cell adhesion protein that was originally identified as a heat stable antigen in mice. It is involved in METASTASIS and is highly expressed in many NEOPLASMS.Antigens, CD13: Zinc-binding metalloproteases that are members of the type II integral membrane metalloproteases. They are expressed by GRANULOCYTES; MONOCYTES; and their precursors as well as by various non-hematopoietic cells. They release an N-terminal amino acid from a peptide, amide or arylamide.Antigens, Protozoan: Any part or derivative of any protozoan that elicits immunity; malaria (Plasmodium) and trypanosome antigens are presently the most frequently encountered.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.Antigens, CD86: A costimulatory ligand expressed by ANTIGEN-PRESENTING CELLS that binds to CD28 ANTIGEN with high specificity and to CTLA-4 ANTIGEN with low specificity. The interaction of CD86 with CD28 ANTIGEN provides a stimulatory signal to T-LYMPHOCYTES, while its interaction with CTLA-4 ANTIGEN may play a role in inducing PERIPHERAL TOLERANCE.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.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.Antigens, Polyomavirus Transforming: Polyomavirus antigens which cause infection and cellular transformation. The large T antigen is necessary for the initiation of viral DNA synthesis, repression of transcription of the early region and is responsible in conjunction with the middle T antigen for the transformation of primary cells. Small T antigen is necessary for the completion of the productive infection cycle.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.HLA Antigens: Antigens determined by leukocyte loci found on chromosome 6, the major histocompatibility loci in humans. They are polypeptides or glycoproteins found on most nucleated cells and platelets, determine tissue types for transplantation, and are associated with certain diseases.Antigens, Differentiation, B-Lymphocyte: Membrane antigens associated with maturation stages of B-lymphocytes, often expressed in tumors of B-cell origin.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.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.NAD+ NucleosidaseAntigens, Fungal: Substances of fungal origin that have antigenic activity.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.H-2 Antigens: The major group of transplantation antigens in the mouse.Sialic Acid Binding Ig-like Lectin 3: A 67-kDa sialic acid binding lectin that is specific for MYELOID CELLS and MONOCYTE-MACROPHAGE PRECURSOR CELLS. This protein is the smallest siglec subtype and contains a single immunoglobulin C2-set domain. It may play a role in intracellular signaling via its interaction with SHP-1 PROTEIN-TYROSINE PHOSPHATASE and SHP-2 PROTEIN-TYROSINE PHOSPHATASE.Antigens, Helminth: Any part or derivative of a helminth that elicits an immune reaction. The most commonly seen helminth antigens are those of the schistosomes.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.Antigens, CD18: Cell-surface glycoprotein beta-chains that are non-covalently linked to specific alpha-chains of the CD11 family of leukocyte-adhesion molecules (RECEPTORS, LEUKOCYTE-ADHESION). A defect in the gene encoding CD18 causes LEUKOCYTE-ADHESION DEFICIENCY SYNDROME.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.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.Membrane Glycoproteins: Glycoproteins found on the membrane or surface 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.Epitopes: Sites on an antigen that interact with specific antibodies.Antigens, CD9: A subtype of tetraspanin proteins that play a role in cell adhesion, cell motility, and tumor metastasis. CD9 antigens take part in the process of platelet activation and aggregation, the formation of paranodal junctions in neuronal tissue, and the fusion of sperm with egg.Carcinoembryonic Antigen: A glycoprotein that is secreted into the luminal surface of the epithelia in the gastrointestinal tract. It is found in the feces and pancreaticobiliary secretions and is used to monitor the response to colon cancer treatment.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.Antigens, CD15: A trisaccharide antigen expressed on glycolipids and many cell-surface glycoproteins. In the blood the antigen is found on the surface of NEUTROPHILS; EOSINOPHILS; and MONOCYTES. In addition, CD15 antigen is a stage-specific embryonic antigen.Antigens, Viral, Tumor: Those proteins recognized by antibodies from serum of animals bearing tumors induced by viruses; these proteins are presumably coded for by the nucleic acids of the same viruses that caused the neoplastic transformation.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Antigens, CD43: A sialic acid-rich protein and an integral cell membrane mucin. It plays an important role in activation of T-LYMPHOCYTES.Antigens, CD36: Leukocyte differentiation antigens and major platelet membrane glycoproteins present on MONOCYTES; ENDOTHELIAL CELLS; PLATELETS; and mammary EPITHELIAL CELLS. They play major roles in CELL ADHESION; SIGNAL TRANSDUCTION; and regulation of angiogenesis. CD36 is a receptor for THROMBOSPONDINS and can act as a scavenger receptor that recognizes and transports oxidized LIPOPROTEINS and FATTY ACIDS.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.Antigens, CD11: A group of three different alpha chains (CD11a, CD11b, CD11c) that are associated with an invariant CD18 beta chain (ANTIGENS, CD18). The three resulting leukocyte-adhesion molecules (RECEPTORS, LEUKOCYTE ADHESION) are LYMPHOCYTE FUNCTION-ASSOCIATED ANTIGEN-1; MACROPHAGE-1 ANTIGEN; and ANTIGEN, P150,95.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.Histocompatibility Antigens: A group of antigens that includes both the major and minor histocompatibility antigens. The former are genetically determined by the major histocompatibility complex. They determine tissue type for transplantation and cause allograft rejections. The latter are systems of allelic alloantigens that can cause weak transplant rejection.Antigens, CD59: Small glycoproteins found on both hematopoietic and non-hematopoietic cells. CD59 restricts the cytolytic activity of homologous complement by binding to C8 and C9 and blocking the assembly of the membrane attack complex. (From Barclay et al., The Leukocyte Antigen FactsBook, 1993, p234)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.Proliferating Cell Nuclear Antigen: Nuclear antigen with a role in DNA synthesis, DNA repair, and cell cycle progression. PCNA is required for the coordinated synthesis of both leading and lagging strands at the replication fork during DNA replication. PCNA expression correlates with the proliferation activity of several malignant and non-malignant cell types.Antigens, CD57: Oligosaccharide antigenic determinants found principally on NK cells and T-cells. Their role in the immune response is poorly understood.Antigens, CD70: A transmembrane protein belonging to the tumor necrosis factor superfamily that specifically binds to CD27 ANTIGEN. It is found on activated T-LYMPHOCYTES; B-LYMPHOCYTES; and DENDRITIC CELLS where it plays a role in stimulating the proliferation of CD4-POSITIVE T-LYMPHOCYTES and CD8-POSITIVE T-LYMPHOCYTES.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.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.Antigens, CD58: Glycoproteins with a wide distribution on hematopoietic and non-hematopoietic cells and strongly expressed on macrophages. CD58 mediates cell adhesion by binding to CD2; (ANTIGENS, CD2); and this enhances antigen-specific T-cell activation.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.Antigens, CD47: A ubiquitously expressed membrane glycoprotein. It interacts with a variety of INTEGRINS and mediates responses to EXTRACELLULAR MATRIX PROTEINS.Antigens, CD11b: A CD antigen that contains a conserved I domain which is involved in ligand binding. When combined with CD18 the two subunits form MACROPHAGE-1 ANTIGEN.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Prostate-Specific Antigen: A glycoprotein that is a kallikrein-like serine proteinase and an esterase, produced by epithelial cells of both normal and malignant prostate tissue. It is an important marker for the diagnosis of prostate cancer.Antigens, CD11c: An integrin alpha subunit of approximately 150-kDa molecular weight. It is expressed at high levels on monocytes and combines with CD18 ANTIGEN to form the cell surface receptor INTEGRIN ALPHAXBETA2. The subunit contains a conserved I-domain which is characteristic of several of alpha integrins.O Antigens: The lipopolysaccharide-protein somatic antigens, usually from gram-negative bacteria, important in the serological classification of enteric bacilli. The O-specific chains determine the specificity of the O antigens of a given serotype. O antigens are the immunodominant part of the lipopolysaccharide molecule in the intact bacterial cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)HLA-A2 Antigen: A specific HLA-A surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-A*02 allele family.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.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Hematopoietic Stem Cells: Progenitor cells from which all blood cells derive.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.Immunoglobulin G: The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.Cell SeparationAntigens, Tumor-Associated, Carbohydrate: Carbohydrate antigens expressed by malignant tissue. They are useful as tumor markers and are measured in the serum by means of a radioimmunoassay employing monoclonal antibodies.Antigens, CD55: GPI-linked membrane proteins broadly distributed among hematopoietic and non-hematopoietic cells. CD55 prevents the assembly of C3 CONVERTASE or accelerates the disassembly of preformed convertase, thus blocking the formation of the membrane attack complex.Antigens, CD31: Cell adhesion molecules present on virtually all monocytes, platelets, and granulocytes. CD31 is highly expressed on endothelial cells and concentrated at the junctions between them.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.Histocompatibility Antigens Class I: Membrane glycoproteins consisting of an alpha subunit and a BETA 2-MICROGLOBULIN beta subunit. In humans, highly polymorphic genes on CHROMOSOME 6 encode the alpha subunits of class I antigens and play an important role in determining the serological specificity of the surface antigen. Class I antigens are found on most nucleated cells and are generally detected by their reactivity with alloantisera. These antigens are recognized during GRAFT REJECTION and restrict cell-mediated lysis of virus-infected cells.Antigens, CD81: Tetraspanin proteins that are involved in a variety of cellular functions including BASEMENT MEMBRANE assembly, and in the formation of a molecular complexes on the surface of LYMPHOCYTES.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.Antigens, CD137: A member of the tumor necrosis factor receptor superfamily that is specific for 4-1BB LIGAND. It is found in a variety of immune cell types including activated T-LYMPHOCYTES; NATURAL KILLER CELLS; and DENDRITIC CELLS. Activation of the receptor on T-LYMPHOCYTES plays a role in their expansion, production of cytokines and survival. Signaling by the activated receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Recombinant Proteins: Proteins prepared by recombinant DNA technology.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.Mice, Inbred BALB CMonocytes: 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.HLA-A Antigens: Polymorphic class I human histocompatibility (HLA) surface antigens present on almost all nucleated cells. At least 20 antigens have been identified which are encoded by the A locus of multiple alleles on chromosome 6. They serve as targets for T-cell cytolytic responses and are involved with acceptance or rejection of tissue/organ grafts.Cross Reactions: Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.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).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.Blood Group Antigens: Sets of cell surface antigens located on BLOOD CELLS. They are usually membrane GLYCOPROTEINS or GLYCOLIPIDS that are antigenically distinguished by their carbohydrate moieties.Hepatitis B Surface Antigens: Those hepatitis B antigens found on the surface of the Dane particle and on the 20 nm spherical and tubular particles. Several subspecificities of the surface antigen are known. These were formerly called the Australia antigen.Antigens, CD63: Ubiquitously-expressed tetraspanin proteins that are found in late ENDOSOMES and LYSOSOMES and have been implicated in intracellular transport of proteins.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.Antibody Specificity: The property of antibodies which enables them to react with some ANTIGENIC DETERMINANTS and not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site.Antigens, CD151: Tetraspanin proteins found associated with LAMININ-binding INTEGRINS. The CD151 antigens may play a role in the regulation of CELL MOTILITY.Antigens, CD79: A component of the B-cell antigen receptor that is involved in B-cell antigen receptor heavy chain transport to the PLASMA MEMBRANE. It is expressed almost exclusively in B-LYMPHOCYTES and serves as a useful marker for B-cell NEOPLASMS.Spleen: An encapsulated lymphatic organ through which venous blood filters.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.HLA-D Antigens: Human immune-response or Class II antigens found mainly, but not exclusively, on B-lymphocytes and produced from genes of the HLA-D locus. They are extremely polymorphic families of glycopeptides, each consisting of two chains, alpha and beta. This group of antigens includes the -DR, -DQ and -DP designations, of which HLA-DR is most studied; some of these glycoproteins are associated with certain diseases, possibly of immune etiology.CD30 Ligand: A membrane-bound tumor necrosis family member found primarily on activated T-LYMPHOCYTES that binds specifically to CD30 ANTIGEN. It may play a role in INFLAMMATION and immune regulation.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.N-Glycosyl Hydrolases: A class of enzymes involved in the hydrolysis of the N-glycosidic bond of nitrogen-linked sugars.Burkitt Lymphoma: A form of undifferentiated malignant LYMPHOMA usually found in central Africa, but also reported in other parts of the world. It is commonly manifested as a large osteolytic lesion in the jaw or as an abdominal mass. B-cell antigens are expressed on the immature cells that make up the tumor in virtually all cases of Burkitt lymphoma. The Epstein-Barr virus (HERPESVIRUS 4, HUMAN) has been isolated from Burkitt lymphoma cases in Africa and it is implicated as the causative agent in these cases; however, most non-African cases are EBV-negative.Receptors, Antigen: Molecules on the surface of B- and T-lymphocytes that recognize and combine with specific antigens.Immunization: Deliberate stimulation of the host's immune response. ACTIVE IMMUNIZATION involves administration of ANTIGENS or IMMUNOLOGIC ADJUVANTS. PASSIVE IMMUNIZATION involves administration of IMMUNE SERA or LYMPHOCYTES or their extracts (e.g., transfer factor, immune RNA) or transplantation of immunocompetent cell producing tissue (thymus or bone marrow).Antibody Formation: The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.Antigens, CD11a: An alpha-integrin subunit found on lymphocytes, granulocytes, macrophages and monocytes. It combines with the integrin beta2 subunit (CD18 ANTIGEN) to form LYMPHOCYTE FUNCTION-ASSOCIATED ANTIGEN-1.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.Hepatitis B Antigens: Antigens of the virion of the HEPATITIS B VIRUS or the Dane particle, its surface (HEPATITIS B SURFACE ANTIGENS), core (HEPATITIS B CORE ANTIGENS), and other associated antigens, including the HEPATITIS B E ANTIGENS.Bone Marrow: The soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells.Antigen-Antibody Reactions: The processes triggered by interactions of ANTIBODIES with their ANTIGENS.Immune Sera: Serum that contains antibodies. It is obtained from an animal that has been immunized either by ANTIGEN injection or infection with microorganisms containing the antigen.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.)Mice, SCID: Mice homozygous for the mutant autosomal recessive gene "scid" which is located on the centromeric end of chromosome 16. These mice lack mature, functional lymphocytes and are thus highly susceptible to lethal opportunistic infections if not chronically treated with antibiotics. The lack of B- and T-cell immunity resembles severe combined immunodeficiency (SCID) syndrome in human infants. SCID mice are useful as animal models since they are receptive to implantation of a human immune system producing SCID-human (SCID-hu) hematochimeric mice.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.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.Cell Division: The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.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.Herpesvirus 4, Human: The type species of LYMPHOCRYPTOVIRUS, subfamily GAMMAHERPESVIRINAE, infecting B-cells in humans. It is thought to be the causative agent of INFECTIOUS MONONUCLEOSIS and is strongly associated with oral hairy leukoplakia (LEUKOPLAKIA, HAIRY;), BURKITT LYMPHOMA; and other malignancies.Receptors, Antigen, T-Cell, alpha-beta: T-cell receptors composed of CD3-associated alpha and beta polypeptide chains and expressed primarily in CD4+ or CD8+ T-cells. Unlike immunoglobulins, the alpha-beta T-cell receptors recognize antigens only when presented in association with major histocompatibility (MHC) molecules.Antibodies, Bacterial: Immunoglobulins produced in a response to BACTERIAL ANTIGENS.HLA-B Antigens: Class I human histocompatibility (HLA) surface antigens encoded by more than 30 detectable alleles on locus B of the HLA complex, the most polymorphic of all the HLA specificities. Several of these antigens (e.g., HLA-B27, -B7, -B8) are strongly associated with predisposition to rheumatoid and other autoimmune disorders. Like other class I HLA determinants, they are involved in the cellular immune reactivity of cytolytic T lymphocytes.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.Bone Marrow Cells: Cells contained in the bone marrow including fat cells (see ADIPOCYTES); STROMAL CELLS; MEGAKARYOCYTES; and the immediate precursors of most blood cells.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.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.MART-1 Antigen: A melanosome-specific protein that plays a role in the expression, stability, trafficking, and processing of GP100 MELANOMA ANTIGEN, which is critical to the formation of Stage II MELANOSOMES. The protein is used as an antigen marker for MELANOMA cells.Antigens, CD147: A widely distributed cell surface transmembrane glycoprotein that stimulates the synthesis of MATRIX METALLOPROTEINASES. It is found at high levels on the surface of malignant NEOPLASMS and may play a role as a mediator of malignant cell behavior.Lymphoma: A general term for various neoplastic diseases of the lymphoid tissue.Mice, Inbred C57BLOvalbumin: An albumin obtained from the white of eggs. It is a member of the serpin superfamily.HIV Antigens: Antigens associated with specific proteins of the human adult T-cell immunodeficiency virus (HIV); also called HTLV-III-associated and lymphadenopathy-associated virus (LAV) antigens.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.HL-60 Cells: A promyelocytic cell line derived from a patient with ACUTE PROMYELOCYTIC LEUKEMIA. HL-60 cells lack specific markers for LYMPHOID CELLS but express surface receptors for FC FRAGMENTS and COMPLEMENT SYSTEM PROTEINS. They also exhibit phagocytic activity and responsiveness to chemotactic stimuli. (From Hay et al., American Type Culture Collection, 7th ed, pp127-8)Antigens, CD82: A widely expressed transmembrane glycoprotein that functions as a METASTASIS suppressor protein. It is underexpressed in a variety of human NEOPLASMS.Immunoenzyme Techniques: Immunologic techniques based on the use of: (1) enzyme-antibody conjugates; (2) enzyme-antigen conjugates; (3) antienzyme antibody followed by its homologous enzyme; or (4) enzyme-antienzyme complexes. These are used histologically for visualizing or labeling tissue specimens.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).Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Antigens, Thy-1: A group of differentiation surface antigens, among the first to be discovered on thymocytes and T-lymphocytes. Originally identified in the mouse, they are also found in other species including humans, and are expressed on brain neurons and other cells.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.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.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.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.Autoantigens: Endogenous tissue constituents that have the ability to interact with AUTOANTIBODIES and cause an immune response.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)Epstein-Barr Virus Nuclear Antigens: Nuclear antigens encoded by VIRAL GENES found in HUMAN HERPESVIRUS 4. At least six nuclear antigens have been identified.Interleukin-2: A soluble substance elaborated by antigen- or mitogen-stimulated T-LYMPHOCYTES which induces DNA synthesis in naive lymphocytes.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.Cell Line, Tumor: A cell line derived from cultured tumor cells.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.H-Y Antigen: A sex-specific cell surface antigen produced by the sex-determining gene of the Y chromosome in mammals. It causes syngeneic grafts from males to females to be rejected and interacts with somatic elements of the embryologic undifferentiated gonad to produce testicular organogenesis.Antigens, CD146: A cell adhesion molecule of the immunoglobulin superfamily that is expressed in ENDOTHELIAL CELLS and is involved in INTERCELLULAR JUNCTIONS.Antigens, Heterophile: Antigens stimulating the formation of, or combining with heterophile antibodies. They are cross-reacting antigens found in phylogenetically unrelated species.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.Antibodies, Monoclonal, Murine-Derived: Antibodies obtained from a single clone of cells grown in mice or rats.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.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.Antigens, CD98: A heterodimeric protein that is a cell surface antigen associated with lymphocyte activation. The initial characterization of this protein revealed one identifiable heavy chain (ANTIGENS, CD98 HEAVY CHAIN) and an indeterminate smaller light chain. It is now known that a variety of light chain subunits (ANTIGENS, CD98 LIGHT CHAINS) can dimerize with the heavy chain. Depending upon its light chain composition a diverse array of functions can be found for this protein. Functions include: type L amino acid transport, type y+L amino acid transport and regulation of cellular fusion.Hepatitis B Core Antigens: The hepatitis B antigen within the core of the Dane particle, the infectious hepatitis virion.Peptides: Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.Antigen-Antibody Complex: The complex formed by the binding of antigen and antibody molecules. The deposition of large antigen-antibody complexes leading to tissue damage causes IMMUNE COMPLEX DISEASES.Lymph Nodes: They are oval or bean shaped bodies (1 - 30 mm in diameter) located along the lymphatic system.Molecular Weight: The sum of the weight of all the atoms in a molecule.Immunodiffusion: Technique involving the diffusion of antigen or antibody through a semisolid medium, usually agar or agarose gel, with the result being a precipitin reaction.HLA-DQ Antigens: A group of the D-related HLA antigens found to differ from the DR antigens in genetic locus and therefore inheritance. These antigens are polymorphic glycoproteins comprising alpha and beta chains and are found on lymphoid and other cells, often associated with certain diseases.Antibodies, Viral: Immunoglobulins produced in response to VIRAL ANTIGENS.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.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.Forssman Antigen: A glycolipid, cross-species antigen that induces production of antisheep hemolysin. It is present on the tissue cells of many species but absent in humans. It is found in many infectious agents.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Antigens, CD274: An inhibitory B7 antigen that has specificity for the T-CELL receptor PROGRAMMED CELL DEATH 1 PROTEIN. CD274 antigen provides negative signals that control and inhibit T-cell responses and is found at higher than normal levels on tumor cells, suggesting its potential role in TUMOR IMMUNE EVASION.Complement Fixation Tests: Serologic tests based on inactivation of complement by the antigen-antibody complex (stage 1). Binding of free complement can be visualized by addition of a second antigen-antibody system such as red cells and appropriate red cell antibody (hemolysin) requiring complement for its completion (stage 2). Failure of the red cells to lyse indicates that a specific antigen-antibody reaction has taken place in stage 1. If red cells lyse, free complement is present indicating no antigen-antibody reaction occurred in stage 1.Simian virus 40: A species of POLYOMAVIRUS originally isolated from Rhesus monkey kidney tissue. It produces malignancy in human and newborn hamster kidney cell cultures.Glycoproteins: Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.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.Isoantigens: 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.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.gp100 Melanoma Antigen: A melanosome-associated protein that plays a role in the maturation of the MELANOSOME.Major Histocompatibility Complex: The genetic region which contains the loci of genes which determine the structure of the serologically defined (SD) and lymphocyte-defined (LD) TRANSPLANTATION ANTIGENS, genes which control the structure of the IMMUNE RESPONSE-ASSOCIATED ANTIGENS, HUMAN; the IMMUNE RESPONSE GENES which control the ability of an animal to respond immunologically to antigenic stimuli, and genes which determine the structure and/or level of the first four components of complement.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.Immunoelectrophoresis: A technique that combines protein electrophoresis and double immunodiffusion. In this procedure proteins are first separated by gel electrophoresis (usually agarose), then made visible by immunodiffusion of specific antibodies. A distinct elliptical precipitin arc results for each protein detectable by the antisera.

Cell surface sialic acid and the regulation of immune cell interactions: the neuraminidase effect reconsidered. (1/1355)

It has been known for over a decade that sialidase (neuraminidase) treatment could substantially enhance the capacity of resting B cells to stimulate the proliferation of allogeneic and antigen specific, syngeneic T cells. Thus, cell-surface sialic acid was implicated as a potential modulator of immune cell interaction. However, little progress has been made in either identifying explicit roles for sialic acid in this system or in hypothesizing mechanisms to explain the "neuraminidase effect." Here we show for the first time that cell surface sialic acid on medium incubated B cells blocks access to costimulatory molecules on the B cell surface, and that this is the most likely explanation for the neuraminidase effect. Further, we show that it is likely to be upregulation of ICAM-1 and its subsequent engagement of LFA-1 rather than loss of cell surface sialic acid that in part regulates access to CD86 and other costimulatory molecules. However, we cannot exclude a role for CD86-bound sialic acid on the B cell in modulating binding to T cell CD28. Because sialidase treatment of resting B cells but not resting T cells enables T cell activation, we suggest that sialidase treatment may still be an analogue for an authentic step in B cell activation, and show that for highly activated B cells (activated with polyclonal anti-IgM plus INF-gamma) there is specific loss 2, 6-linked sialic acid. Potential roles for sialic acid in modulating B cell/T cell collaboration are discussed.  (+info)

The role of interleukin 12 in the development of atherosclerosis in ApoE-deficient mice. (2/1355)

The cytokine profile of atherosclerotic aortas from apoE-deficient mice was assessed by reverse transcriptase-polymerase chain reaction. The results clearly showed that the expression of mRNA for IL-12p40 was evident in aortas from 3-month-old apoE-deficient mice. The mRNA for IL-10 was detected in aorta from these mice at the age of 6 months, indicating that expression of IL-12 is earlier than that of IL-10 in these animals. Concurrent with IL-12p40, the mRNA for the T-cell cytokine IFN-gamma, but not IL-4, was detected in aortas of mice at young and old ages. Both in situ hybridization and immunostaining further demonstrated the localization of IL-12 in macrophages of atherosclerotic lesions. Immunohistochemistry also demonstrated the expression of costimulatory molecules B7-1 and B7-2 in macrophages, suggesting that activation of T lymphocytes by macrophages may occur via surface antigens in lesions. When the immunoglobulin isotype of the antioxidized LDL antibodies in sera of apoE-deficient mice was determined, it revealed that both IgM and IgG were present. Furthermore, IgG2a is predominant and comprises approximately 50% of the antioxidized LDL IgG in sera from young mice (3 months), but decreased to lower levels (35%) in older mice (6 months). Daily administration of IL-12 led to an increase in serum levels of antioxidized LDL antibodies and accelerated atherosclerosis in young apoE-deficient mice compared with control mice injected with PBS alone. Taken together, these data suggest that IL-12 plays an active role in regulating the immune response during the early phase of atherosclerosis in apoE-deficient mice.  (+info)

B7-2 expressed on EL4 lymphoma suppresses antitumor immunity by an interleukin 4-dependent mechanism. (3/1355)

For T cells to become functionally activated they require at least two signals. The B7 costimulatory molecules B7-1 and B7-2 provide the "second signal" pivotal for T cell activation. In this report, we studied the relative roles of B7-1 and B7-2 molecules in the induction of antitumor immunity to the T cell thymoma, EL4. We generated EL4 tumor cells that expressed B7-1, B7-2, and B7-1+B7-2 by transfecting murine cDNAs. Our results demonstrate that EL4-B7-1 cells are completely rejected in syngeneic mice. Unlike EL4-B7-1 cells, we find that EL4-B7-2 cells are not rejected but progressively grow in the mice. A B7-1- and B7-2-EL4 double transfectant was generated by introducing B7-2 cDNA into the EL4-B7-1 tumor line that regressed in vivo. The EL4-B7-1+B7-2 double transfectant was not rejected when implanted into syngeneic mice but progressively grew to produce tumors. The double transfectant EL4 cells could costimulate T cell proliferation that could be blocked by anti-B7-1 antibodies, anti-B7-2 antibodies, or hCTLA4 immunoglobulin, showing that the B7-1 and B7-2 molecules expressed on the EL4 cells were functional. In vivo, treatment of mice implanted with double-transfected EL4 cells with anti-B7-2 monoclonal antibody resulted in tumor rejection. Furthermore, the EL4-B7-2 and EL4-B7-1+B7-2 cells, but not the wild-type EL4 cells, were rejected in interleukin 4 (IL-4) knockout mice. Our data suggests that B7-2 expressed on some T cell tumors inhibits development of antitumor immunity, and IL-4 appears to play a critical role in abrogation of the antitumor immune response.  (+info)

Intracellular adhesion molecule-1 modulates beta-chemokines and directly costimulates T cells in vivo. (4/1355)

The potential roles of adhesion molecules in the expansion of T cell-mediated immune responses in the periphery were examined using DNA immunogen constructs as model antigens. We coimmunized cDNA expression cassettes encoding the adhesion molecules intracellular adhesion molecule-1 (ICAM-1), lymphocyte function associated-3 (LFA-3), and vascular cell adhesion molecule-1 (VCAM-1) along with DNA immunogens, and we analyzed the resulting antigen-specific immune responses. We observed that antigen-specific T-cell responses can be enhanced by the coexpression of DNA immunogen and adhesion molecules ICAM-1 and LFA-3. Coexpression of ICAM-1 or LFA-3 molecules along with DNA immunogens resulted in a significant enhancement of T-helper cell proliferative responses. In addition, coimmunization with pCICAM-1 (and more moderately with pCLFA-3) resulted in a dramatic enhancement of CD8-restricted cytotoxic T-lymphocyte responses. Although VCAM-1 and ICAM-1 are similar in size, VCAM-1 coimmunization did not have any measurable effect on cell-mediated responses. These results suggest that ICAM-1 and LFA-3 provide direct T-cell costimulation. These observations are further supported by the finding that coinjection with ICAM-1 dramatically enhanced the level of interferon-gamma (IFN-gamma) and beta-chemokines macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, and regulated on activation normal T-cell expression and secreted (RANTES) produced by stimulated T cells. Through comparative studies, we observed that ICAM-1/LFA-1 T-cell costimulatory pathways are independent of CD86/CD28 pathways and that they may synergistically expand T-cell responses in vivo.  (+info)

In vivo UVA-1 and UVB irradiation differentially perturbs the antigen-presenting function of human epidermal Langerhans cells. (5/1355)

Ultraviolet B (UVB, 290-320 nm) radiation is known to suppress the immune function of epidermal Langerhans cells. We have recently described that in vitro UVB irradiation perturbs the antigen-presenting cell function of Langerhans cells by inhibiting their expression of functional B7 costimulatory molecules (B7-1, B7-2). The aim of this study was to determine wavelength-specific UV effects on Langerhans cells function in vivo, specifically UVB and UVA-1. To address this issue, volunteers were irradiated on the sun protected volar aspects of their forearms with 3 x minimal erythema dose of UVB (Philips TL-12) and UVA-1 (UVASUN 5000 Mutzhaas). Langerhans cells were isolated from suction blister roofs immediately following irradiation. Langerhans cells isolated from UVB- but not from UVA-1-irradiated skin failed to activate naive resting allogeneic T cells (mixed epidermal cell leukocyte reaction) or primed tetanus toxoid reactive autologous T cells. Langerhans cells isolated from sham-irradiated or UVA-1-irradiated skin strongly upregulated B7-2 molecules during short-term tissue culture. By contrast, Langerhans cells from UVB-irradiated skin did not upregulate B7-2 molecules. Furthermore, exogenous stimulation of the B7 pathway by anti-CD28 stimulatory monoclonal antibodies restored the capacity of UVB-irradiated Langerhans cells to activate both alloreactive and tetanus toxoid-reactive T cells, implying suppressed antigen-presenting cell activities and perturbed B7 expression of Langerhans cells isolated from UVB-irradiated skin are related. Those studies demonstrate that in vivo UVB, but not UVA-1, interferes with the activation-dependent upregulation of B7 molecules on Langerhans cells, which in turn is of functional relevance for the perturbed antigen-presenting cell function of Langerhans cells within UVB- but not UVA-1-irradiated skin.  (+info)

Evidence of cell-mediated cardiac myocyte injury involved in the heart failure of a patient with progressive systemic sclerosis. (6/1355)

A 54-year-old woman with progressive systemic sclerosis (PSS) was admitted to hospital because of dyspnea and chest pain. Echocardiogram revealed diffuse hypokinesis of the left ventricle (ejection fraction 24%). Methylprednisolone, heparin, and diuretics were administered, without benefit. Anemia, thrombocytopenia, and renal dysfunction rapidly progressed, and she died of heart failure on the 14th hospital day. Immunohistochemical study of the myocardial tissue showed mild to moderate cell infiltration, mainly consisting of natural killer (NK) cells, macrophages, cytotoxic T lymphocytes (CTLs), and T helper cells. Perforin, a cytolytic factor, was expressed in the infiltrating CTLs and NK cells, indicating that these cells were activated killer cells. Furthermore, human leukocyte antigen classes I and II, intercellular adhesion molecule-1, as well as costimulatory molecules B7-1, B7-2, and CD40, all of which are known not to be expressed in cardiac myocytes under normal conditions, were moderately to strongly expressed in cardiac myocytes. There was no detectable level of enterovirus genomes in the polymerase chain reaction products from the myocardial tissue of this patient. These findings strongly suggest that the infiltrating killer cells recognized cardiac myocytes as target cells and directly damaged them by releasing perforin. Enhanced expression of these antigens may have played an important role in the activation and cytotoxicity of the infiltrating killer cells. Absence of enterovirus genomes in the myocardial tissue may suggest that this autoimmune process is primarily induced by PSS.  (+info)

Synovial fluid transforming growth factor beta inhibits dendritic cell-T lymphocyte interactions in patients with chronic arthritis. (7/1355)

OBJECTIVE: To examine whether rheumatoid synovial fluid (SF) inhibits dendritic cell (DC) expression of the CD80 and CD86 costimulator molecules and contributes to SF T lymphocyte hyporesponsiveness. METHODS: Cell-free rheumatoid SF was tested for its effect on DC-stimulated autologous/allogeneic mixed lymphocyte reactions and for its effect on DC surface antigen expression, as assessed by flow cytometry. Blocking monoclonal antibodies were used to identify the SF cytokines that inhibited DC-T lymphocyte interactions. RESULTS: Low concentrations of SF (2.5%) could inhibit DC-mediated autologous and allogeneic T lymphocyte proliferation. This inhibitory effect could be reversed by neutralizing transforming growth factor beta (TGFbeta) and interleukin-2 (IL-2), but not by IL-12, in the SF. Hyaluronic acid, IL-6, IL-10, and tumor necrosis factor alpha were not associated with SF inhibition. In vitro culture alone and crosslinking with the CD40 ligand up-regulated DC CD80/CD86 expression and costimulator function, and this was not affected by inclusion of SF. In the presence of SF, DC clustered with autologous T lymphocytes showed decreased CD80 and CD86 expression, and variable CD80/CD86 decreases were observed on DC clustered with allogeneic T lymphocytes. CONCLUSIONS: TGFbeta in SF appears to suppress T lymphocyte function, which may affect both signaling to DC and the induction of DC costimulator function.  (+info)

Phenotypic analysis of lymphocytes and monocytes/macrophages in peripheral blood and bronchoalveolar lavage fluid from patients with pulmonary sarcoidosis. (8/1355)

BACKGROUND: The granulomatous inflammation in sarcoidosis is driven by the interplay between T cells and macrophages. To gain a better understanding of this process the expression by these cells of cell surface activation markers, co-stimulatory molecules, and adhesion molecules was analysed. METHODS: CD4+ and CD8+ T lymphocytes from peripheral blood (PBL) or bronchoalveolar lavage (BAL) fluid, as well as paired peripheral blood monocytes and alveolar macrophages from 27 patients with sarcoidosis were analysed by flow cytometry. RESULTS: CD26, CD54, CD69, CD95, and gp240 were all overexpressed in T cells from BAL fluid compared with those from PBL in both the CD4+ and CD8+ subsets, while CD57 was overexpressed only in BAL CD4+ cells. In contrast, CD28 tended to be underexpressed in the BAL T cells. Monocyte/macrophage markers included CD11a, CD11b, CD11c, CD14, CD16, CD54, CD71, CD80 and CD86 and HLA class II. CD11a expression in alveolar macrophages (and peripheral blood monocytes) was increased in patients with active disease and correlated positively with the percentage of BAL lymphocytes. Expression of CD80 in macrophages correlated with the BAL CD4/CD8 ratio. CONCLUSIONS: Our data indicate substantial activation of both CD4+ and CD8+ lung T cells in sarcoidosis. There were also increased numbers of BAL lymphocytes whose phenotypic characteristics have earlier been associated with clonally expanded, replicatively senescent cells of the Th1 type.  (+info)

We have previously demonstrated that the inhibitory effects of IL-10 on ConA-induced T cell proliferation or IL-2 production by resting murine T cells were only observed when macrophages, but not when activated B cells, dendritic cells, or L cells, were used as accessory cells. To further elucidate the mechanism of action of IL-10 on the inhibition of macrophage costimulatory activity, we have used a system in which macrophages can develop into effective costimulator cells and the effect of IL-10 on this process can be studied in the absence of T cells. After fixation, resting macrophages have no costimulatory activity for soluble anti-CD3-induced T cell proliferation nor do they express the activation Ag B7/BB1. In contrast, macrophages activated by culture alone, or by culture with IFN gamma or LPS for 24 h, and then fixed, were effective accessory cells, expressed B7, and their costimulatory activity correlated with their level of cell surface B7 expression. Addition of IL-10 during the ...
Activation of CD4+ T cells occurs through the simultaneous engagement of the T-cell receptor and a co-stimulatory molecule (like CD28, or ICOS) on the T cell by the major histocompatibility complex (MHCII) peptide and co-stimulatory molecules on the APC. Both are required for production of an effective immune response; in the absence of co-stimulation, T cell receptor signalling alone results in anergy. The signalling pathways downstream from co-stimulatory molecules usually engages the PI3K pathway generating PIP3 at the plasma membrane and recruiting PH domain containing signaling molecules like PDK1 that are essential for the activation of PKCθ, and eventual IL-2 production. Optimal CD8+ T cell response relies on CD4+ signalling.[33] CD4+ cells are useful in the initial antigenic activation of naïve CD8 T cells, and sustaining memory CD8+ T cells in the aftermath of an acute infection. Therefore, activation of CD4+ T cells can be beneficial to the action of CD8+ T cells.[34][35][36] The ...
To our knowledge, expression of B7-H1 within RCC tumors of the kidney has not been previously demonstrated. We also believe that B7-H1 is the first T cell costimulatory molecule that has been reported to exhibit a strong association with the aggressiveness of a solid (nonhematologic) tumor and patient cancer-specific survival. Finally, our study provides previously undescribed evidence that B7-H1 may function at the clinical level to promote cancer progression, perhaps through impairment of host T cell-mediated immunity, as has recently been reported in the basic scientific literature (2, 6).. B7-H1 represents a recently identified cell-surface glycoprotein belonging to the B7 family of costimulatory molecules (1). Constitutive B7-H1 protein expression is normally restricted to macrophage-lineage cells, where it may participate in the costimulatory activation of naïve T cells or deletion of activated T cells (1, 23). Several human cancers, however, have also been reported to aberrantly express ...
Results In their resting state the monocyte derived dendritic cells expressed MHC class II, but very low levels of co-stimulatory molecules CD80, CD83 and CD86. Upon culture with H. pylori, the cells expressed significantly higher levels of these co-stimulatory molecules, demonstrating maturation (,25 fold increase in percentage of positive events for CD80, CD83, CD86 on flow cytometry; p,0.01). There were no differences between the responses to wild type and dupA knockout mutant strains, or following stimulation with lipopolysaccharide (LPS). The H. pylori-matured dendritic cells secreted high levels of IL-12p40, IL-12p70, IL-10 and IL-23. The concentrations induced by the dupA+ strains were significantly higher than those induced by the dupA mutants (1.5 fold increase in IL-12p40 production, p,0.05; 1.4 fold increase in IL-12p70, p,0.05).. ...
The neisserial porins are the major protein components of the outer membrane of the pathogenic Neisseria (N. meningitidis and N. gonorrhoeae). They have been shown to be able to enhance the immune response to poorly immunogenic substances (e.g., polysaccharides, peptides, glycolipids, etc.). To explore the basis of their potent adjuvant activity, the effect of the neisserial porins on T-B cell interactions and T cell costimulation was examined. Neisserial porins increased the surface expression of the costimulatory ligand B7-2 (CD86) but did not affect the expression of B7-1 (CD80). In addition, incubation with the neisserial porins increased the T lymphocyte costimulatory ability of B lymphocytes, which was inhibited by anti-B7-2 but not anti-B7-1 monoclonal antibodies. Upregulation of B7-2 on the surface of B lymphocytes may be the mechanism behind the immunopotentiating activity of neisserial porins. ...
The study of the ontogeny of skin APCs also provides a unique opportunity to evaluate the development and, thus, the phenotype of their precursor cells. In addition, despite considerable research, the relationship among LCs, dermal DCs, and skin macrophages still remains unclear, not least because of the high plasticity of precursors to differentiate into each of these cells in different microenvironments (7, 12, 15). In this study, we show that at 9 wk EGA, skin macrophages and DCs can already be phenotypically separated by the distinct expression of the DC marker CD1c on some HLA-DRhigh cells. HLA-DRhigh leukocytes are capable of phagocytosing bacteria, up-regulating costimulatory molecules, and stimulating proliferation of allogeneic T cells in vitro, thus confirming their DC nature. In contrast, HLA-DRlow skin macrophages neither express CD1c nor up-regulate costimulatory molecules during culture. Collectively, these data show that at 9 wk EGA, skin macrophages and DCs can already be ...
The modulation of co-stimulatory pathways represents a novel therapeutic strategy to regulate autoimmune diseases. Auto-reactive CD4+ T cells play a critical role in initiating the immune response leading to inflammation and autoimmune diseases. Blocking co-stimulatory signals prevents T-cell activation, thus diminishing autoimmune responses and possibly preventing the progression of autoimmune disease. Blockade of several co-stimulatory pathways has been investigated in animal models and has led to clinical trials testing specific blocking agents in humans. In this review we will describe the role of co-stimulatory pathways, primarily the CD28-B7 pathway, in autoimmune diseases, and we will present in vivo and in vitro studies supporting the efficacy of co-stimulation blockade in animal models of autoimmune disease. Finally, we will discuss the clinical therapeutic efficacy of blocking monoclonal antibodies in preventing or reducing auto-antigen driven T-cell activation in humans with ...
Allostimulatory and processing capacities of D1 cells. (a) Mixed lymphocyte reaction (MLR) by sorted I-Abright and I-Aint D1 cells shows that the mature I-
Background HIV Top notch controllers (EC) suppress HIV viremia without ART yet previous studies demonstrated that EC maintain an activated T cell phenotype. were quantified using ELISA. Results In the EChi group expression of activation exhaustion and immunosensescence markers on T cells were significantly reduced compared to the EClo group and similar to the seronegative controls. The EChi group expressed higher levels of co-stimulatory molecules CD28 and CD73 and had WYE-125132 lower levels of monocyte activation (HLA-DR expression) with a reduced frequency of inflammatory monocyte (CD14++CD16+) subset. Furthermore the EChi group maintained a stable CD4% during a median follow up of six years. Conclusions Elite controllers with preserved CD4 T cells (EChi) have normal T cell and monocyte phenotypes and therefore may have limited benefit from antiretroviral therapy (ART). CD4% can be an important marker WYE-125132 for evaluating future studies aimed at determining the need for ART in this group ...
Our study is the first to evaluate the role of CD40L-induced maturation as a component of the DC manufacturing process in a prospectively randomized trial. At the time we began this trial, it was known that CD40 activation of murine and human DCs led to enhanced generation of CTLs by increasing DC expression of the costimulatory molecules CD80 and CD86 and by inducing IL-12 secretion (14, 18). It had also been showed that activating murine tumor lysate-pulsed DCs with CD40L led to more potent induction of systemic immunity than DCs prepared without CD40L activation (14). Therefore, we hypothesized that CD40L-activated human DCs would induce a more potent immune response than DCs grown without a specific maturation factor. However, treatment of DCs with CD40L did not increase tumor or KLH-specific immune responses in our patients. It is unlikely that this was due to inactive or inadequate amounts of CD40L, as we observed significant upregulation of CD86 and CD83 expression. One possible ...
Within the paradigm of the two-signal model of lymphocyte activation, the interest in costimulation has witnessed a remarkable emergence in the past few years with the discovery of a large array of molecules that can serve this role, including some with an inhibitory function. Interest has been further enhanced by the realization of these molecules potential as targets to modulate clinical immune responses. Although the therapeutic translation of mechanistic knowledge in costimulatory molecules has been relatively straightforward, the capacity to target their inhibitory counterparts has remained limited. This limited capacity is particularly apparent in the case of the cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), a major negative regulator of T cell responses. Because there have been several previous comprehensive reviews on the function of this molecule, we focus here on the physiological implications of its structural features. Such an exercise may ultimately help us to design
|p|The mouse monoclonal antibody recognizes human CD40, a member of the TNFreceptor superfamily. CD40 is a receptor on antigen-presenting cells of the immune system and is essential for mediating a broad variety of immune and inflammatory responses includ
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Antigen presentation is upregulated (MHC II, CD86). M2c macrophages are important for secretion of IL-10, TGF-β. They also ... Typical are pro - inflammatory molecules (e.g. IFN-γ, IL-12, IL-23, TNF, IL-6, IL-1, specific chemokines and antigen ... Ability of TAMs to present tumour-associated antigens is decreased as well as stimulation of the anti-tumour functions of T and ...
The markers include CD11c, CD80, CD83, CD86, and major histocompatibility complex class II antigens. The neoplastic dendritic ... Dendritic cells function as antigen-presenting cells. They process antigen material and present it on the surface to other ... February 2002). "Expression of CD86 in acute myelogenous leukemia is a marker of dendritic/monocytic lineage". Exp. Hematol. 30 ...
When activated by Toll-like receptor ligands, the CD80 expression is upregulated in antigen presenting cells (APCs). The CD86 ... Mouse CD Antigen Chart Human CD Antigen Chart Human CD28 genome location and CD28 gene details page in the UCSC Genome Browser. ... Association of the TCR of a naive T cell with MHC:antigen complex without CD28:B7 interaction results in a T cell that is ... Schneider H, Cai YC, Prasad KV, Shoelson SE, Rudd CE (Apr 1995). "T cell antigen CD28 binds to the GRB-2/SOS complex, ...
It acts as an "off" switch when bound to CD80 or CD86 on the surface of antigen-presenting cells. The CTLA-4 protein is encoded ... on antigen-presenting cells. CTLA-4 binds CD80 and CD86 with greater affinity and avidity than CD28 thus enabling it to ... CTLA4 is homologous to the T-cell co-stimulatory protein, CD28, and both molecules bind to CD80 and CD86, also called B7-1 and ... In 1987, cytotoxic T-lymphocyte antigen 4, or CTLA-4, was identified by Pierre Golstein and colleagues . In November 1995, the ...
"CD26 Mediates Dissociation of Tollip and IRAK-1 from Caveolin-1 and Induces Upregulation of CD86 on Antigen-Presenting Cells". ...
This suggests Treg-mediated suppression of antigen presenting cells is a multi-step process. In addition to CTLA-4 CD80/CD86 ... T regulatory cell adhesion to antigen presenting dendritic cell causes sequestration of Fascin-1, an actin-bundling protein ... essential for immunological synapse formation, and skews Fascin-1-dependent actin polarization in antigen presenting dendritic ...
... and CD86; in myelin membrane adhesion molecules; in junctional adhesion molecules (JAM); in tyrosine-protein kinase receptors; ... and in the programmed cell death protein 1 (PD1). Immunoglobulin V-set, subgroup InterPro: IPR003596 T-cell surface antigen CD2 ... CD86; CD8A; CD8B; CD8B1; CD96; CEACAM1; CEACAM16; CEACAM19; CEACAM21; CEACAM3; CEACAM4; CEACAM5; CEACAM6; CEACAM7; CEACAM8; ...
Mregs express high levels of co-stimulatory molecules (CD86) and MHC Class II, they have the highest expression of these ... T cells co-culture with Mregs showed intense activation and proliferation, so Mregs act as sufficient antigen-presenting cells ...
... these T cells must rely on the activation of CD28 for confirmation that they recognise a foreign antigen (as CD80/CD86 is only ... For example, when an antigen-presenting cell expresses an antigen on MHC class II, a CD4+ cell will aid those cells through a ... that a host antigen is foreign. As a result, the CD8+ T cells treat the host cell presenting that antigen as infected, and go ... but unprocessed antigens do not interact with T cells and are not involved in their activation. The antigens that bind to MHC ...
CD86, ED1 macrophage antigen, CD4, and leukocyte common antigen. These activated microglia decrease the ability for neurons to ... Additionally, T cells may enter through the blood-brain barrier, be activated by local antigen presenting cells, and attack the ...
In order for T cells to be activated and attack an antigen, that antigen must be presented to the T cell by an antigen- ... and the other signal is the CD80 or CD86 molecule (also known as B7-1 and B7-2). Abatacept binds to the CD80 and CD86 molecule ... Abatacept prevents antigen-presenting cells (APCs) from delivering the co-stimulatory signal. This prevents the T cells from ... One of those signals is the major histocompatibility complex (MHC), combined with the antigen, ...
The antigens recognized by non-Vδ2 T cells expanded in the above infectious contexts have not been characterized, but the fact ... CD86) and adhesion receptors (CD11a, CD18, CD54). Thus activated Vγ9Vδ2 T cells behave like APCs (γδ T-APC) and present ... It is still not clear whether these non-peptidic antigens bind directly to the Vγ9/Vδ2 TCR or if a presenting element exists. ... However, none of the known antigen-presenting molecules like MHC class I and II or CD1 are required for γδ T cell activation ...
... antigens, cd79 MeSH D23.050.301.264.035.180 --- antigens, cd80 MeSH D23.050.301.264.035.186 --- antigens, cd86 MeSH D23.050. ... antigens, cd79 MeSH D23.101.100.110.180 --- antigens, cd80 MeSH D23.101.100.110.186 --- antigens, cd86 MeSH D23.101.100.110.194 ... hla-a antigens MeSH D23.050.301.500.450.370.372 --- hla-a1 antigen MeSH D23.050.301.500.450.370.374 --- hla-a2 antigen MeSH ... hla-b antigens MeSH D23.050.301.500.450.380.383 --- hla-b7 antigen MeSH D23.050.301.500.450.380.385 --- hla-b8 antigen MeSH ...
Antigen Antigenicity Immunogen Superantigen Allergen Hapten Epitope Linear Conformational Mimotope Tumor antigen Antigen- ... Expressed by APCs CD86 - Expressed by APCs CD28 family receptors CD28 - Expressed by T Cells CD278 (ICOS) - Homodimer, ... T cells Antigen receptor - T cell receptor (TCR) Subunits - [email protected] / [email protected] / [email protected] / [email protected] Co-receptors CD8 (CD8α / CD8β) CD4 ... B cells Antigen receptor - B cell receptor (BCR) Subunits- Immunoglobulin heavy chain / Immunoglobulin light chain Co-receptors ...
Antigen-naïve T cells expand and differentiate into memory and effector T cells after they encounter their cognate antigen ... so co-stimulation for these cells comes from the CD80 and CD86 proteins, which together constitute the B7 protein, (B7.1 and ... These self-antigens are expressed by thymic cortical epithelial cells on MHC molecules on the surface of cortical epithelial ... The second signal licenses the T cell to respond to an antigen. Without it, the T cell becomes anergic, and it becomes more ...
Binding with its two ligands are CD80 and CD86, expressed on dendritic cells, prompts T cell expansion. CD28 was the target of ... CD27 - This molecule supports antigen-specific expansion of naïve T cells and is vital for the generation of T cell memory. ... The ligand for GITR is mainly expressed on antigen presenting cells. Antibodies to GITR have been shown to promote an anti- ... CD40 - This molecule, found on a variety of immune system cells including antigen presenting cells has CD40L, otherwise known ...
Interaction with B7 on T cells Downregulation of CD80/CD86 costimultory molecules on antigen presenting cells upon interaction ... tumor antigens, alloantigens, and self-antigens in inflamed tissue. Immune recognition of non-self-antigens typically ... Self-antigens are present due to endogenous expression, importation of antigen from peripheral sites via circulating blood, and ... Upon exposure to a foreign antigen, either the antigen is eliminated by the standard immune response (resistance), or the ...
... the T-cell receptor binding to an antigen-MHC complex and T-cell surface receptor CD28 binding to CD80 or CD86 proteins. CTLA4 ... Dendritic cells are antigen presenting cells (APCs) in the mammalian immune system. In cancer treatment they aid cancer antigen ... Cancer vaccine Antigen 5T4 Chimeric antigen receptor Coley's Toxins Combinatorial ablation and immunotherapy Cryoimmunotherapy ... Antigens can be added to the antibody and can induce the dendritic cells to mature and provide immunity to the tumor. Dendritic ...
Cluster of Differentiation 86 (also known as CD86 and B7-2) is a protein expressed on antigen-presenting cells that provides ... "Entrez Gene: CD86 CD86 molecule". Human CD86 genome location and CD86 gene details page in the UCSC Genome Browser. Davila S, ... CD86 works in tandem with CD80 to prime T cells. The CD86 gene encodes a type I membrane protein that is a member of the ... Pan XM, Gao LB, Liang WB, Liu Y, Zhu Y, Tang M, Li YB, Zhang L (July 2010). "CD86 +1057 G/A polymorphism and the risk of ...
... is required in addition to the antigen-specific signal from their antigen receptors. T cells require two signals ... and CD86 (B7.2) on the membrane of APC. Another costimulatory receptor expressed by T cells is ICOS ( Inducible Costimulator), ... B cell binds antigens with its BCR (a membrane-bound antibody), which transfers intracellular signals to the B cell as well as ... This additional binding makes the B cells 100- to 10,000-fold more sensitive to antigen. CR2 on mature B cells forms a complex ...
... or CD86 (B7.2), although other additional co-stimulation molecules have been identified. When Signal 2 is not expressed, but T ... As specific cancer antigens have been discovered, these antigens can be loaded to aAPCs to successfully stimulate and expand ... It is the specific antigen or epitope that is loaded into the MHC determines the antigen-specificity. The peptide-loaded MHC ... Antigen presenting cells are the sentinels of the immune system and patrol the body for pathogens. When they encounter foreign ...
IL-10 is partially responsible for reducing expression of co-stimulatory molecules such as CD86 on macrophages. CD86 is one of ... A helminth protein, or helminthic antigen, is a protein derived from a parasitic worm that causes an immune reaction. When ... Of these, NPA (nematode polyprotein antigen/allergen) FAR, and Sj-FABPc demonstrate different binding affinities for fatty ... and are implicated in reduced reactivity to other antigens. Other helminth proteins promote parasite survival in other ways, ...
The axis inhibits bone marrow-derived dendritic cells (i.e. antigen-presenting cells that process antigen material, present it ... CD86, CD40, and MHC class II molecules) that are critical for developing adaptive immune responses. IL receptor-activated bone ...
There are two major types of B7 proteins: B7-1 or CD80, and B7-2 or CD86. However, it is not known if they differ significantly ... This is also called "Signal 1" and its main purpose is to guarantee antigen specificity of the T cell activation. However, MHC ... B7 is a type of peripheral membrane protein found on activated antigen presenting cells (APC) that, when paired with either a ...
Function in antigen presentation[edit]. HSPs are indispensable components of antigen presentation pathways - the classical ones ... CD86, CD40), MHC molecules and pro-inflammatory and Th1 cytokines.[25][28] ... Nishikawa M, Takemoto S, Takakura Y (April 2008). "Heat shock protein derivatives for delivery of antigens to antigen ... "Human heat shock protein 70 enhances tumor antigen presentation through complex formation and intracellular antigen delivery ...
Every helper T-cell is specific to one particular antigen. Only professional antigen-presenting cells (macrophages, B ... Histiocyte Macrophage List of human clusters of differentiation for a list of CD molecules (such as CD80 and CD86) Steinman, R ... Their main function is to process antigen material and present it on the cell surface to the T cells of the immune system. They ... Here they act as antigen-presenting cells: they activate helper T-cells and killer T-cells as well as B-cells by presenting ...
CD86 • CD87 • CD88 • CD89 • CD90 • CD91- CD92 • CD93 • CD94 • CD95 • CD96 • CD97 • CD98 • CD99 • CD100 ... 2000). "Characterization of a new member of the TNF family expressed on antigen presenting cells.". Biol. Chem. 380 (12): 1443- ... "BLyS receptor signatures resolve homeostatically independent compartments among naïve and antigen-experienced B cells.". Semin ...
Two major types of alloantigens are blood group antigens and histocompatibility antigens. In alloimmunity, the body creates ... for instance CD152/CTLA-4 receptor which binds CD80 and CD86 as well). If T-lymphocyte does not receive costimulatory signal, ... Antigen presentation by chemically modified splenocytes induces antigen-specific T cell unresponsiveness in vitro and in vivo. ... 6(3):505-13 Yu G, Xu X, Vu MD, Kilpatrick ED, Li XC (2006), NK cells promote transplant tolerance by killing donor antigen- ...

No data available that match "antigens cd86"


  • Giguère JF, Bounou S, Paquette JS, Madrenas J, Tremblay MJ: Insertion of host-derived costimulatory molecules CD80 (B7.1) and CD86 (B7.2) into human immunodeficiency virus type 1 affects the virus life cycle. (exbio.cz)
  • One of its responses to a foreign antigen is the proliferation of a class of lymphocytes which specifically recognizes the antigen. (google.com)
  • Mϕ play a crucial role in human host defense by secreting cytokines and chemokines, presenting antigen to T lymphocytes and clearing infectious agents. (pnas.org)
  • Recent reports demonstrated that osteoblast-like cells can also exert activities directly associated with the immune system (cytokine synthesis, antigen presentation, phagocytosis and stimulation of T lymphocytes). (portlandpress.com)
  • Analysis of TCR Vα chain expressed by antigen‐specific, conventional CD 4 + T lymphocytes reveals that Treg depletion allows the emergence of a wider repertoire comprising novel, mostly private, antigen‐specific clonotypes. (embopress.org)
  • Complex interactions between T and B lymphocytes and antigen presenting cells (APC) lead to inflammation, cytokine production, IgE production, and bronchial hyperresponsiveness (BHR). (bmj.com)
  • Recognizes a protein of 70 kDa, which is identified as CD86. (biotium.com)
  • Recombinant protein encompassing a sequence within the center region of human CD86. (genetex.com)
  • Purified CD86 (AAH40261.1, 24 a.a. - 246 a.a.) human recombinant protein with His-Flag-StrepII tag at N-terminus expressed in human cells. (abnova.com)
  • Transfection of pSuper-CD86 plasmid into HEK293T cell, and the expressed protein was purified by Strep -Tactin affinity column. (abnova.com)
  • High protein-loading efficiency was obtained by testing with the model antigen ovalbumin (Ova), and the Ova adsorbed onto the cationic CS/ O -HTCC complexes was taken up easily by the epithelium. (dovepress.com)
  • DNA vaccines are based on the delivery of genes encoding a specific protein antigen that is transcribed and translated by host cells [ 4 , 5 ]. (omicsonline.org)
  • The CD152 antigen, also called CTLA4, is an integral membrane protein belonging to the immunoglobulin superfamily, which is expressed either as a 30 kDa monomer or as a disulfide-linked homodimer. (beckman.com)
  • A small recombinant fragment of human CD86 was characterized that corresponds to amino acid residues 1-111 (CD86 111 ) of the mature protein. (aacrjournals.org)
  • Induction therapy with monoclonal antibodies specific for CD80 and CD86 delays the onset of acute renal allograft rejection in non-human primates. (nih.gov)
  • DNA can present antigens in a suitable molecular form, ranging from full-length sequence to short MHC class I- or II-binding epitopes, to optimize induction of T-cell responses [ 6 ]. (omicsonline.org)
  • 88% viable (n = 16), conserved their phenotype and maintained integral biological activities including dextran uptake, production of immunostimulatory cytokines/chemokines and antigen presentation. (biomedcentral.com)
  • The immune system can promptly respond to millions of foreign antigens. (google.com)
  • In contrast, binding of CD86 to CTLA-4 regulates T cell activation and diminishes the immune response. (miltenyibiotec.com)
  • We tested whether activated MSCs qualify for the induction of antigen-specific immune regulation. (frontiersin.org)
  • Bone marrow derived human MSCs were activated by interferon-γ and analyzed for antigen uptake and processing and immune regulatory features including phenotype, immunosuppressive capacity, and metabolic activity. (frontiersin.org)
  • However, despite all the practical advantages, DNA vaccines face challenges in inducing potent antigen specific immune responses and protection in humans. (omicsonline.org)
  • Collectively, these studies illustrate an additional mechanism whereby Tregs control the immune response to non‐self‐antigens. (embopress.org)
  • Treg depletion before immunization leads to enhanced antigen specific immune responses in a TCR Vβ transgenic mouse model. (embopress.org)
  • Lu YJ, Oliver E, Zhang F, Pope C, Finn A, Malley R. Screening for Th17-dependent pneumococcal vaccine antigens: comparison of murine and human cellular immune responses. (childrenshospital.org)
  • Detects human B7‑2/CD86 in direct ELISAs and Western blots. (novusbio.com)
  • Proliferative responses were significantly strong but became much stronger when DCs were concomitantly incubated with soluble antigens and human recombinant TNF-α and used subsequently as stimulators. (springer.com)
  • Tested positive against native human antigen. (creativebiomart.net)
  • IFN-γ, in turn, activates Mϕ and enhances cytokine secretion, antigen presentation and, supposedly, the bactericidal activity of Mϕ ( 6 ). (pnas.org)
  • This review discusses the mechanisms and potential therapeutic applications of antigen-specific T cell tolerance techniques using syngeneic apoptotic cellular carriers and synthetic nanoparticles that are covalently cross-linked to diabetogenic peptides or proteins through ethylene carbodiimide (ECDI) to prevent and treat T1D. (soc-bdr.org)
  • Ts Pmy was able to activate mouse bone marrow-derived DCs to semi-mature status characterized by expressing surface CD40 and CD86, but not CD80 and MHCII. (biomedcentral.com)
  • A) Experiments were performed in the presence of 10 μg/mL of anti-CD80 (Mab 104), anti-CD86 (IT2-2), anti-CD80 plus anti-CD86, or isotype match control. (bloodjournal.org)
  • Taken together, this novel vaccine platform is well suited to deliver antigens and immunostimulatory cytokines to DCs and to initiate and maintain protective immunity. (asm.org)
  • As an ideal intranasal vaccine adjuvant, it should have the properties of assisting soluble antigens to pass the mucosal barrier and potentiating both systemic and mucosal immunity via nasal administration. (dovepress.com)
  • Therefore, these results suggest that CS/ O -HTCC nanoparticles are ideal vaccine adjuvants for soluble antigens used in intranasal or mucosal vaccination. (dovepress.com)
  • Thus, our study revealed that DCs utilize autophagic machinery to optimally process and present extracellular microbial antigens for MHC II presentation. (nih.gov)
  • Although induction of metabolic autophagy did not enhance MHC II presentation, autophagic machinery was required for optimal phagosome-to-lysosome fusion and subsequent processing of antigen for MHC II loading. (nih.gov)
  • Belatacept binds to CD86 with a 4-fold higher affinity than abatacept. (drugbank.ca)
  • Purified by antigen-affinity chromatography. (genetex.com)
  • If a T cell receptor recognise the self antigen and the MHC very well and there is a strong affinity and interaction the T-cell is likely to have perfect recognition of the self antigen and apoptosis takes place and programmed cell death occurs. (infobarrel.com)
  • Here we show that peripheral blood eosinophils from hypereosinophilic patients could express membrane CD86 but not CD80. (rupress.org)
  • Ex vivo AqH-derived myeloid DC showed elevated class I and II MHC and CCR5, but reduced CD86 compared to matched peripheral blood DC. (arvojournals.org)
  • Analysis of MR1T cell clones revealed specificity for distinct cell-derived antigens and alternative transcriptional strategies for metabolic programming, cell cycle control and functional polarization following antigen stimulation. (elifesciences.org)
  • We have developed our programs using insights from our proprietary tumor antigen discovery platform, EDGE™, together with an immunotherapy platform which has demonstrated the ability to elicit an enhanced antigen-directed T-cell response in preclinical primate models. (benzinga.com)
  • For antitumor immunotherapy based on DCs, various strategies of antigen loading have been proposed (including whole tumor-cell lysates). (spandidos-publications.com)