LFN-γ Production in Response to Neuropathogenic Cas-Br-M Murine Leukemia Virus Infection

T cell-mediated production of IFN-γ followed infection of adult, but not neonatal NFS/N mice with Cas-Br-M murine leukemia virus (Cas). The IFN-γ response was associated with the appearance of CTL specific for Cas and with age-dependent resistance to neurologic disease. While both immune responses were mediated by a CD8-enriched population of T cells, IFN-γ did not play a role in the activation of the Cas-specific CTL response. However, when given exogenously, IFN-γ delayed the onset and reduced the incidence of Cas-induced neurologic disease. These data suggest that the IFN-γ response to Cas infection may be an important host defense mechanism whose effects on virus replication and neurologic disease expression are independent of its effect on Cas-specific CTL.