Characterization of virus-induced interferon-gamma responses in mice previously infected with murine cytomegalovirus

These studies demonstrate that in vitro stimulation of spleen cells from murine cytomegalovirus (MCMV) immune mice with MCMV-infected fibroblasts induces production of interferon (IFN)-gamma. This response is specific to MCMV, is not generalized to heterologous viruses, and also is not H-2 restricted. Both early and late CMV antigens induce IFN-gamma. In in vitro cell depletion and direct cell selection experiments, T lymphocytes were responsible for IFN-gamma production. Although both CD4 and CD8 cells appear to be required to induce the response, the cell subset that releases the IFN-gamma is not yet undefined. In vivo, this IFN-gamma response appears early after acute infection and persists > or =1 year. The response is not seen in T cell-deficient mice. Thus, previous MCMV infection results in a virus-specific IFN-gamma response in spleen cells exposed to MCMV antigens. The pathophysiologic significance of these observations is now under study.