Effector cytolotic function but not IFN-gamma production in cytotoxic T cells triggered by virus-infected target cells in vitro.
Cytolysis and interferon(IFN)-gamma production are two independent effector functions of activated cytotoxic T (Tc) cells. We have used the Tc-cell response against the flavivirus, Murray Valley encephalitis virus (MVE), to investigate the requirements for inducing these two functions with regard to antigen-concentration and CD8 coreceptor involvement. Cognate peptide-pulsed target cells triggered cytolysis by primary ex vivo MVE-immune as well as in vitro peptide-restimulated splenocytes at lower peptide concentrations than IFNgamma-production (100-fold lower in the case of primary ex vivo effectors). Little difference was observed in CD8 dependency. Importantly, neither of the effector populations were triggered to produce IFN-gamma by virus-infected target cells, although cytolysis occurred. This result raises the possibility that the levels of presentation of cognate antigen on virus-infected cells in vivo may be below the threshold required for the IFN-gamma production.
Regner
M
M
Division of Immunology and Cell Biology, John Curtin School of Medical Research, Australian National University, PO Box334, Canberra, ACT 2601, Australia.
Lobigs
M
M
Blanden
R V
RV
Müllbacher
A
A
D000818:Animals; D000956:Antigens, Viral / Q000276:immunology; D016827:CD8 Antigens / Q000276:immunology*; D002460:Cell Line; D003602:Cytotoxicity, Immunologic / Q000276:immunology*; D018068:Encephalitis Virus, Murray Valley / Q000276:immunology; D005260:Female; D007371:Interferon-gamma / Q000096:biosynthesis*; D051379:Mice; D008808:Mice, Inbred CBA; D010455:Peptides / Q000276:immunology; D011971:Receptors, Immunologic / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000821:virology; D014407:Tumor Cells, Cultured
D000956:Antigens, Viral; D016827:CD8 Antigens; D010455:Peptides; D011971:Receptors, Immunologic; D007371:Interferon-gamma