Antigen

About: Antigen is a research topic. Over the lifetime, 170233 publications have been published within this topic receiving 6982342 citations. The topic is also known as: antibody generator & Antigen.

Expression of Programmed Death 1 Ligands by Murine T Cells and APC

Abstract: Programmed death 1 (PD-1) is a new member of the CD28/CTLA-4 family, which has been implicated in the maintenance of peripheral tolerance. Two ligands for PD-1, namely, B7-H1 (PD-L1) and B7-DC (PD-L2), have recently been identified as new members of the B7 family but their expression at the protein level remains largely unknown. To characterize the expression of B7-H1 and B7-DC, we newly generated an anti-mouse B7-H1 mAb (MIH6) and an anti-mouse B7-DC mAb (TY25). MIH6 and TY25 immunoprecipitated a single molecule of 43 and 42 kDa from the lysate of B7-H1 and B7-DC transfectants, respectively. Flow cytometric analysis revealed that B7-H1 was broadly expressed on the surface of mouse tumor cell lines while the expression of B7-DC was rather restricted. PD-1 was expressed on anti-CD3-stimulated T cells and anti-IgM plus anti-CD40-stimulated B cells at high levels but was undetectable on activated macrophages or DCs. B7-H1 was constitutively expressed on freshly isolated splenic T cells, B cells, macrophages, and dendritic cells (DCs), and up-regulated on T cells by anti-CD3 stimulation on macrophages by LPS, IFN-gamma, GM-CSF, or IL-4, and on DCs by IFN-gamma, GM-CSF, or IL-4. In contrast, B7-DC expression was only inducible on macrophages and DCs upon stimulation with IFN-gamma, GM-CSF, or IL-4. The inducible expression of PD-1 ligands on both T cells and APCs may suggest new paradigms of PD-1-mediated immune regulation.

Antigen-inducible, H-2-restricted, interleukin-2-producing T cell hybridomas. Lack of independent antigen and H-2 recognition

Abstract: We developed a method for production of antigen-specific, H-2-restricted T cell hybrids. The tumor cell partner in the fusions was itself a T cell hybrid, FS6-14.13.AG2 (or its derivatives), which could be induced to produce the growth factor, interleukin-2 (IL-2), in response to a challenge with concanavalin A, but had no known antigen specificity. The normal T cell partner in the fusions was a population of lymph node T cell blasts that had been highly enriched in antigen-specific, H-2-restricted T cells by in vivo immunization, followed by in vitro challenge with antigen and clonal expansion in IL-2-containing medium. These fusions produced hybrids that grew constitutively in culture. A sizable proportion of the hybrids demonstrated the ability to produce IL-2 in response to a challenge with specific antigen presented by irradiated spleen cells of the appropriate H-2 type. Four cloned antigen/H-2-specific hybrid lines were produced. AO-40.10 responded to chicken ovalbumin (OVA) when presented by I-A(k)-bearing cells. DC1.18.3 responded to the apo form of beef cytochrome c when presented with I-A(d). AODK-10.4 responded to keyhole limpet hemocyanin (KLH) presented with I-A (d). AODK-1.16 also responded to KLH presented by a product of the I region of H-2(d), but the data were consistent with either a product of the I-J-I-E(d) region or a combinatorial molecule with elements from both I-A(d) and I-E(d)/I-C(d). Coincidentally, AO-40.10 was shown to have an unexpected alloreactivity with a product of H-2(b) mapping to the K-I-A region. These hybrids should prove invaluable as sources of monoclonal material for the study of the receptor(s) on T cells with H-2-restricted antigen specificities. We also generated T cell hybrids with two antigen/H-2 specificities by fusing an azaguanine-resistant clone of AO-40.10 to normal T cells with a different antigen/H-2 specificity. Many of the hybrids retained reactivity to OVA plus H-2(a) and to the second antigen/H-2 combination. None reacted to either OVA plus the second H-2 type or to the second antigen plus H-2(a). One of these hybrids was successfully cloned to produce the line AOFK- 11.11.1. It retained the ability to recognize OVA plus I-A(k) inherited from one parent, and KLH plus IA(f) inherited from the other. It did not recognize OVA plus IA(f) or KLH plus I-A(k). These results have some bearing on models describing the nature of T cell receptors for antigen recognized in association with H-2 products. They do not support models in which antigen and H-2 are recognized separately by two independent T cell receptors.

Direct Visualization of Antigen-specific CD8+T Cells during the Primary Immune Response to Epstein-Barr Virus In Vivo

Abstract: Primary infection with virus can stimulate a vigorous cytotoxic T cell response. The magnitude of the antigen-specific component versus the bystander component of a primary T cell response remains controversial. In this study, we have used tetrameric major histocompatibility complex–peptide complexes to directly visualize antigen-specific cluster of differentration (CD)8+ T cells during the primary immune response to Epstein-Barr virus (EBV) infection in humans. We show that massive expansion of activated, antigen-specific T cells occurs during the primary response to this virus. In one individual, T cells specific for a single EBV epitope comprised 44% of the total CD8+ T cells within peripheral blood. The majority of the antigen-specific cells had an activated/memory phenotype, with expression of human histocompatibility leukocyte antigen (HLA) DR, CD38, and CD45RO, downregulation of CD62 leukocyte (CD62L), and low levels of expression of CD45RA. After recovery from AIM, the frequency of antigen-specific T cells fell in most donors studied, although populations of antigen-specific cells continued to be easily detectable for at least 3 yr.

A listing of human tumor antigens recognized by T cells.

Abstract: Complete list of abbreviations of tumor antigens 707-AP 707 alanine proline-AFP alpha (α)-fetoprotein-ART-4 adenocarcinoma antigen recognized by T cells 4 BAGE B antigen-β-catenin/m β-catenin/mutated-Bcr-abl breakpoint cluster region-Abelson - CAMEL CTL-recognized antigen on melanoma CAP-1 carcinoembryonic antigen peptide-1-CASP-8 caspase-8 CDC27m cell-division-cycle 27 mutated-CDK4/m cycline-dependent kinase 4 mutated-CEA carcino-embryonic antigen-CT cancer/testis (antigen)-Cyp-B cyclophilin B DAM differentiation antigen melanoma (the epitopes of DAM-6 and DAM-10 are equivalent, but the gene sequences are different; DAM-6 is also called MAGE-B2. and DAM-10 is also called MAGE-B1) ELF2M elongation factor 2 mutated ETV6-AML1 Ets variant gene 6/acute myeloid leukemia 1 gene ETS G250 glycoprotein 250 - GAGE G antigen GnT-V N-acetylglucosaminyltransferase V -Gp100 glycoprotein 100 kDa-HAGE helicose antigen-HER-2/neu human epidermal receptor-2/ neurological - HLA-A * 0201-R1701 arginine (R) to isoleucine (I) exchange at residue 170 of the α-helix of the α2-domain in the HLA-A2 gene HPV-E7 human papilloma virus E7 HSP70-2M heat shock protein 70-2 mutated HST-2 human signet ring tumor-2 hTERT or hTRT human telomerase reverse transcriptase-iCE intestinal carboxyl esterase KIAA0205 name of the gene as it appears in databases-LAGE L antigen LDLR/FUT low-density lipid receptor/GDP-L-fucose: β-D-galactosidase 2-α-L-fucosyltransferase MAGE melanoma antigen MART-1/Melan-A melanoma antigen recognized by T cells-1/melanoma antigen A MC1R melanocortin 1 receptor Myosin/m myosin mutated-MUC1 mucin 1-MUM-1, -2, -3 melanoma ubiquitous mutated 1, 2, 3 NA88-A NA cDNA clone of patient M88-NY-ESO-1 New York-esophagus 1 - P15 protein 15 p190 minor bcr-abl protein of 190 kDa ber-abl Pml/RARα promyelocytic leukaemia/retinoic acid receptor α-PRAME preferentially expressed antigen of melanoma PSA prostate-specific antigen-PSM prostate-specific membrane antigen-RAGE renal antigen RU1 or RU2 renal ubiquitous 1 or 2 SAGE sarcoma antigen SART-1 or SART-3 squamous antigen rejecting tumor 1 or 3-TEL/ AML1 translocation Ets-family leukemia/acute myeloid leukemia 1 TPI/m triosephosphate isomerase mutated TRP-1 tyrosinase related protein 1, or gp75 TRP-2 tyrosinase related protein 2 TRP-2/ INT2 TRP-2/intron 2 WT1 Wilms' tumor gene Abbreviations used ALL acute lymphoblastic leukemia AML acute myeloid leukemia-APL acute promyelocytic leukemia-CML chronic myelogenous leuke mia-CTL cytotoxic T lymphocytes-Ets E-26 transforming specific (family of transcription factors) H/N head and neck-MHC major histocompatibility complex-NSCLC non-small cell lung carcinoma-ORF open reading frame RCC renal cell carcinoma-SCC squamous cell carcinoma-TSTA tumor-specific transplantation antigens.