Lipopolysaccharide interferes with the induction of peripheral T cell death.
In mice injected with superantigens, T cells specific for that antigen proliferate and then die. It has been suggested that the target cells die because they encounter superantigen on the surfaces of nonprofessional presenting cells, such as B cells, which cannot deliver costimulatory signals to T cells. A number of reagents that induce costimulatory molecules on B cells were tested. Lipopolysaccharide very effectively prevented T cell death driven by superantigen. Perhaps surprisingly, the action of lipopolysaccharide was not mediated through the expected costimulatory molecule, B7. Rather, the effects of lipopolysaccharide involved the production of inflammatory cytokines, in particular TNF alpha. The rescued cells survived in vitro culture and were resistant to Fas-induced killing. These data demonstrate that LPS can block antigen-induced T cell death perhaps by interfering with Fas signaling.
Vella
A T
AT
Howard Hughes Medical Institute, Department of Medicine, National Jewish Center for Immunology and Respiratory Medicine, Denver, Colorado 80206.
McCormack
J E
JE
Linsley
P S
PS
Kappler
J W
JW
Marrack
P
P
D000818:Animals; D000954:Antigens, Surface / Q000276:immunology*; D017209:Apoptosis / Q000276:immunology; D018122:B7-1 Antigen / Q000276:immunology; D002470:Cell Survival / Q000187:drug effects* / Q000276:immunology; D004768:Enterotoxins / Q000276:immunology; D005260:Female; D008070:Lipopolysaccharides / Q000494:pharmacology*; D051379:Mice; D008815:Mice, Inbred Strains; D015398:Signal Transduction / Q000276:immunology; D018089:Superantigens / Q000276:immunology; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000276:immunology / Q000502:physiology*; D019014:fas Receptor
D000954:Antigens, Surface; D018122:B7-1 Antigen; D004768:Enterotoxins; D008070:Lipopolysaccharides; D018089:Superantigens; D014409:Tumor Necrosis Factor-alpha; D019014:fas Receptor; C026066:enterotoxin A, Staphylococcal