Influence of HLA class I- and class II-specific monoclonal antibodies on DR-restricted lymphoproliferative responses. I. Unseparated populations of effector cells.
L1-16, a DR-specific, nonpolymorphic monoclonal antibody (MoAb) recognizing the beta-chain of the molecule, blocked virus-specific as well as allogeneic-proliferative T cell responses, whereas another nonpolymorphic anti-DR MoAb blocked proliferative responses to allogeneic cells only. IL 2-supernatants reversed the blocking induced by L1-16. On the other hand class I-specific MoAb B1-23-2 (HLA-A-B-C-specific) and M 18 (beta 2 microglobulin-specific) and their F(ab')2 fragments blocked equally virus-specific or allogeneic proliferative responses. IL 2-containing supernatants did not reverse this phenomenon. Neither anti-class I nor anti-class II MoAb inhibited the IL 2-induced proliferation of IL 2-dependent established T cell lines. MoAb acted neither at the antigen-presenting cell level nor by a toxic effect nor by inducing suppressor cells. These results suggest that a) different epitopes of the DR molecule can be involved during responses to influenza viruses and allogeneic antigens; b) the epitope recognized by L1-16 on the beta-chain of the DR molecule seem necessary for IL 2 production by lymphocytes after activation with influenza antigens; and c) class I-specific MoAb block DR-restricted proliferative responses of lymphocytes by an as yet unknown mechanism.
D000328:Adult; D000911:Antibodies, Monoclonal / Q000145:classification / Q000276:immunology / Q000502:physiology*; D001667:Binding, Competitive; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D005802:Genes, MHC Class II; D006680:HLA Antigens / Q000145:classification / Q000276:immunology*; D006684:HLA-DR Antigens; D006801:Humans; D007251:Influenza, Human / Q000276:immunology; D007376:Interleukin-2 / Q000502:physiology; D008213:Lymphocyte Activation; D010835:Phytohemagglutinins / Q000494:pharmacology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
D000911:Antibodies, Monoclonal; D006680:HLA Antigens; D006684:HLA-DR Antigens; D007376:Interleukin-2; D010835:Phytohemagglutinins