title: Murine sera cytotoxicity toward human B cells and their effect on human mixed lymphocyte reactions.
abstract: Seven murine anti-H-2 and three nonimmune mouse sera were tested for cytotoxicity toward B and T lymphocytes from a panel of human donors. One group of sera, including two anti-H-2.33 sera, exhibited cytotoxicity directed exclusively toward human B but not T cells from all donors. Absorption studies on human lymphoblastoid cell lines (LCLs) of B or T cell origin corroborated these findings. Some nonimmune sera showed similar characteristics, indicating that the observed reactions were not attributable to cross-reactivities between mouse H-2K or D specificities and human antigens coded by the HLA-A, B, or C locus. Another set of mouse sera (anti-H-2.28b and anti-H-2.31) was highly cytotoxic to both B and T cells of some donors but not of others, suggesting that activity in these sera may arise from cross-reactions between mouse and human specifities. A third set of anti-H-2 as well as normal mouse sera showed only background cytotoxicity when tested on human cells. The ability of the B cell cytotoxic mouse sera to block the human mixed lymphocyte culture reaction (MLR) was compared to that of appropriate human alloantisera with exclusive B cell activity or a rabbit serum raised against human B cells. None of the mouse sera resulted in a significant reduction in the human MLR, whereas the human alloantisera as well as the rabbit antiserum caused a significant amount of blocking at several dilutions beyond their highest cytolytic titer.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D003429:Cross Reactions; D006183:H-2 Antigens / Q000276:immunology; D006680:HLA Antigens / Q000276:immunology; D006649:Histocompatibility Antigens / Q000276:immunology*; D006801:Humans; D007518:Isoantibodies / Q000276:immunology*; D007959:Lymphocyte Culture Test, Mixed; D008214:Lymphocytes / Q000276:immunology; D051379:Mice; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D006183:H-2 Antigens; D006680:HLA Antigens; D006649:Histocompatibility Antigens; D007518:Isoantibodies