Inhibition of graft rejection by LPS: further evidence for effects on T lymphocytes.
The effects of bacterial lipopolysaccharides (LPS) on the growth of allografted lymphoma cells in Balb/c mice were studied. It was determined that the injection of LPS at the time of graft implantation resulted in a transient proliferation and a delay in the rejection of the graft. This effect was not attributable to any enhancement of proliferation of the lymphoma cells by LPS nor to any activity of LPS as a competing antigen or as a polyclonal activator of antibody formation. The in vitro cytotoxicity of peritoneal macrophages from LPS-treated animals against allogeneic lymphoma cells was equal to that of mice not treated with LPS. In vitro proliferation responses of splenic lymphocytes from LPS-treated animals indicated that LPS treatment produced a differential depression of Concanavalin A (Con A) responses but phytohemagglutinin (PHA)-induced responses were elevated significantly. These results suggest that the LPS-induced impairment of cell-mediated immunity involves a subset of Con A reactive T cells whose function is important in allograft rejection.
D000818:Animals; D000917:Antibody Formation; D003602:Cytotoxicity, Immunologic; D005260:Female; D006084:Graft Rejection / Q000187:drug effects*; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008213:Lymphocyte Activation; D008223:Lymphoma / Q000276:immunology*; D008264:Macrophages / Q000502:physiology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009374:Neoplasms, Experimental / Q000276:immunology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D014184:Transplantation, Homologous
D008070:Lipopolysaccharides