title: Involvement of CD45 in MHC class II-allospecific cytotoxicity.
abstract: Twenty-seven different CD45 monoclonal antibodies (mAb) were assessed for their ability to block cytotoxicity of alloreactive CD4+ MHC class II-specific or CD8+ class I-specific human T cell clones (n = 3 and 5, respectively). Twelve of 27 blocked the former but only 1/27 the latter, although all 27 significantly inhibited MHC-unrestricted lysis of K562 cells by either CD4+ or CD8+ clones. MAb pretreatment of effector cells but not target cells resulted in retention of blocking. Crosslinking the CD45 with goat anti-mouse Ig serum did not result in blockade of lysis by class I-specific clones or reveal blocking of class II-specific clones not inhibited by mAb alone. These results suggest that CD45 molecules may be predominantly involved in MHC class II-specific but not class I-specific allocytotoxicity as well as MHC-unrestricted natural killer-like cytotoxicity.
authors.affiliation: Second Department of Internal Medicine, University Medical Clinic, Tübingen, Federal Republic of Germany.
authors.forename: G
authors.initials: G
authors.lastname: Pawelec
authors.forename: H J
authors.initials: HJ
authors.lastname: Bühring
authors.forename: C
authors.initials: C
authors.lastname: Müller
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD / Q000276:immunology*; D000943:Antigens, Differentiation / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D006681:HLA-D Antigens / Q000276:immunology*; D006649:Histocompatibility Antigens / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D006801:Humans; D007111:Immunity, Cellular; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000276:immunology; D017493:Leukocyte Common Antigens; D008285:Major Histocompatibility Complex
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D006681:HLA-D Antigens; D006649:Histocompatibility Antigens; D015395:Histocompatibility Antigens Class I; D017493:Leukocyte Common Antigens