Mouse alloantibodies capable of blocking cytotoxic T cell function. IV. Comparative analysis of the blocking effects of anti-Lyt-2 and anti-H-2 antibodies on allogeneic and PHA-mediated killing.
Blocking of cell-mediated lympholysis (CML) by anti-Lyt-2 antibodies was compared with that by anti-H-2 antibodies which most likely inhibit CML by blocking antigen recognition by cytotoxic T lymphocytes (CTLs). Both antibodies were shown to inhibit the early Mg2+-dependent process of killing. Moreover, the anti-H-2-sensitive event was found to be reversible by the antibody as was the case with the anti-Lyt-2-sensitive event, suggesting that the two antibodies block the same event taking place during the Mg2+-dependent stage. Both types of antibody were also shown to be capable of inhibiting the phytohemagglutinin (PHA)-mediated non-specific killing activity of CTLs. However, in the case of anti-Lyt-2 antibodies, available monoclonal antibodies failed to inhibit PHA-mediated killing whereas conventional antisera did. The results thus suggest multiplicity and heterogeneity of Lyt-2 determinants or the existence of multiple products of Lyt-2-linked genes. In addition, an anti-H-2 antiserum also exerted a specific inhibitory effect on PHA-mediated killing. Thus there appears to be a general requirement for involvement of the Lyt-2 molecules on CTLs and major histocompatibility complex (MHC) products on the target cells. The implications of these observations are discussed.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D001666:Binding Sites, Antibody / Q000187:drug effects; D003602:Cytotoxicity, Immunologic; D005260:Female; D006183:H-2 Antigens / Q000276:immunology; D007518:Isoantibodies / Q000276:immunology*; D008274:Magnesium / Q000494:pharmacology; D008285:Major Histocompatibility Complex / Q000187:drug effects; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D010835:Phytohemagglutinins / Q000494:pharmacology; D051381:Rats; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects / Q000276:immunology*
D000911:Antibodies, Monoclonal; D006183:H-2 Antigens; D007518:Isoantibodies; C029805:Lyt antibodies; D010835:Phytohemagglutinins; C030036:anti-H-2 antibodies; D008274:Magnesium