title: Cell-mediated cytotoxicity against HLA-D-region products expressed in monocytes and B lymphocytes. I. Blocking by Unlabelled cells and inhibition by antisera.
abstract: Cytotoxic effector cells against HLA-D-region produts were generated in cultures with HLA-A- and B-matched, HLA-D-mismatched stimulating cells. Monocytes from unrelated donors sharing HLA-D/DR antigens with the primary stimulator were used as target cells. Lysis of target cells was inhibited by addition of unlabelled monocytes having the same HLA-D/DR antigens. Inhibition of cytotoxicity was also observed with unlabelled B cells, but T lymphocytes had little effect. The distribution of the target antigens, therefore, fits the known distribution of the products of HLA-D. In other experiments, a human alloantiserum specific for HLA-DRw3 was found to inhibit cellular cytotoxicity specific for HLA-D/DRw3. Lysis by HLA-D/DRw3-specific effector cells was not inhibited by sera against HLA-DRw2 or DRw7 or by antibodies against HLA-B8 using HLA-B8 positive, DRw3 positive targer cells. A xenogeneic serum against human Ia antigens, produced in rabbits, blocked cytotoxicity directed at DRw2, DRw3 and DRw4. These results suggest that cell-mediated cyctotoxicity was directed against HLA-D/DR or very closely associated determinants.
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D001402:B-Lymphocytes / Q000276:immunology*; D001667:Binding, Competitive; D003602:Cytotoxicity, Immunologic; D000939:Epitopes; D006680:HLA Antigens / Q000235:genetics* / Q000276:immunology; D006801:Humans; D007106:Immune Sera / Q000494:pharmacology; D009000:Monocytes / Q000276:immunology*; D014176:Protein Biosynthesis; D011817:Rabbits
chemical_list: D000939:Epitopes; D006680:HLA Antigens; D007106:Immune Sera