Murine cytomegalovirus independently inhibits priming of helper and cytotoxic T lymphocytes.
Murine cytomegalovirus (MCMV) inhibits antigen-specific cytotoxic T lymphocyte (CTL) priming in vivo (Campbell et al., 1989). To address the mechanism of this immune suppression, two possibilities were considered: (1) MCMV directly interferes with in vivo priming of CTL precursors (CTLp), or (2) MCMV suppresses T helper cell functions necessary for CTL priming. We therefore quantitated T helper cell function in MCMV-infected, SV40-immune mice and assessed dependency of SV40-specific CTLp priming on T helper cell activity. MCMV infection of H-2b mice significantly suppressed the frequency of IL-2 producing T helper cells generated in SV40-immune mice. This suppression was not due to alterations in the number or percentage of CD4 lymphocytes. The helper cell deficiency correlated with suppressed SV40-specific CTL activity. However, CTLp priming in vivo was found to be independent of CD4 T helper cells and IL-2. Therefore, the suppressive effects of MCMV on helper and cytotoxic T cell functions are independent, implying that MCMV directly inhibits an event in lymphocyte priming common to both helper and cytotoxic T cells.
Slater
J S
JS
Department of Microbiology and Immunology, Eastern Virginia Medical School, Norfolk 23501.
Futch
W S
WS
Cavanaugh
V J
VJ
Campbell
A E
AE
D000818:Animals; D015704:CD4 Antigens / Q000032:analysis; D002460:Cell Line; D002461:Cell Line, Transformed; D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000276:immunology*; D007376:Interleukin-2 / Q000096:biosynthesis / Q000494:pharmacology; D015847:Interleukin-4 / Q000096:biosynthesis; D008198:Lymph Nodes / Q000276:immunology; D008212:Lymphocyte Depletion; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010641:Phenotype; D011994:Recombinant Proteins / Q000494:pharmacology; D013539:Simian virus 40 / Q000235:genetics; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000187:drug effects / Q000276:immunology*
D015704:CD4 Antigens; D007376:Interleukin-2; D011994:Recombinant Proteins; D015847:Interleukin-4