CD8 T cells can protect against an intracellular bacterium in an interferon gamma-independent fashion.
Specific T-cell immunity to Listeria monocytogenes is thought to occur through the action of lymphokines which activate phagocytes to ingest and kill microorganisms. Interferon gamma (IFN-gamma) has been shown to be an effective mediator of this type of macrophage activation in vivo and in vitro. The monoclonal antibody H22.1 efficiently neutralizes endogenous IFN-gamma, exacerbates disease in a mouse model of L. monocytogenes infection, and inhibits the in vivo protective activity of a Listeria antigen-specific CD4 T-cell line. In contrast, in vivo protection by Listeria-immune CD8 T cells is not inhibited by the neutralizing anti-IFN-gamma monoclonal antibody. These results suggest that CD8 T cells can protect against an intracellular pathogen in an IFN-gamma-independent manner.
Howard Hughes Medical Institute, Seattle, WA.
J T
JT
Harty
R D
RD
Schreiber
M J
MJ
Bevan
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016827:CD8 Antigens / Q000032:analysis; D003602:Cytotoxicity, Immunologic; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D007111:Immunity, Cellular; D007116:Immunization, Passive; D007371:Interferon-gamma / Q000502:physiology*; D008089:Listeria monocytogenes / Q000276:immunology; D008088:Listeriosis / Q000276:immunology*; D008212:Lymphocyte Depletion; D051379:Mice; D008811:Mice, Inbred DBA; D016176:T-Lymphocyte Subsets / Q000276:immunology*
D016827:CD8 Antigens; D000949:Histocompatibility Antigens Class II; D007371:Interferon-gamma