title: A new monoclonal antibody recognizing an antigen of human lymphocytes similar or identical to Tac antigen.
abstract: A new mouse monoclonal antibody (HIEI, IgG1 type) that reacts with a cell surface glycoprotein of human lymphocytes was isolated. Membrane immunofluorescence assay showed that HIEI, like the anti-Tac monoclonal antibody, reacted preferentially with activated normal human T-cells and adult T-cell leukemia (ATL) virus (ATLV)-carrying human T- and B-cell lines. However, an interesting difference between HIEI and anti-Tac antibody was that HIEI did not react with ATLV-transformed simian cell lines or those cultured with interleukin-2 (IL-2), whereas the anti-Tac antibody did. The immunoprecipitation assay showed that both HIEI and anti-Tac antibody precipitated a glycoprotein with a molecular weight of 60,000 daltons (gp60) from activated normal T-cells and ATLV-positive T- and B-cells, and also gp53 from MT-2 and MT-2-related T-cell lines transformed with ATLV in vitro by the MT-2 cocultivation method. HIEI inhibited the IL-2-dependent proliferation of normal T-cells, but its inhibitory effect was much weaker than that of the anti-Tac antibody. The anti-Tac antibody interfered with the binding of HIEI to target cells, but HIEI did not block binding of the anti-Tac antibody to the cells. These observations indicate that HIEI antibody recognizes a new antigenic determinant of the human Tac antigen.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D000954:Antigens, Surface / Q000276:immunology*; D002460:Cell Line; D017977:Deltaretrovirus; D000939:Epitopes / Q000276:immunology; D006023:Glycoproteins / Q000276:immunology; D006801:Humans; D007938:Leukemia / Q000276:immunology; D008213:Lymphocyte Activation; D008565:Membrane Proteins / Q000276:immunology; D051379:Mice; D012192:Retroviridae Infections / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D000939:Epitopes; D006023:Glycoproteins; D008565:Membrane Proteins; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7