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 mu rine cytomegalovirus (MCMV) immune mice with MCMV-infected fibroblasts indu ces production of interferon (IFN)-gamma. This response is specific to MCMV , is not generalized to heterologous viruses, and also is not H-2 restricte d. Both early and late CMV antigens induce IFN-gamma. In in vitro cell depl etion and direct cell selection experiments, T lymphocytes were responsible for IFN-gamma production. Although both CD4 and CD8 cells appear to be req uired to induce the response, the cell subset that releases the IFN-gamma i s not yet undefined. In vivo, this IFN-gamma response appears early after a cute infection and persists greater than or equal to1 year. The response is not seen in T cell-deficient mice. Thus, previous MCMV infection results i n a virus-specific IFN-gamma response in spleen cells exposed to MCMV antig ens. The pathophysiologic significance of these observations is now under s tudy.