IFNG and infection: Surface staining for viral antigen (ovalbumin)-specific TCR (Figures 3E and 3F) or intracellular staining for IFN-γ production after brief antigenic (ovalbumin) stimulation in culture (Figures 3G and 3H) demonstrated that in spleens and draining lymph nodes of WT mice, MHV-OVA-specific CD8+ T cells (undetectable prior to infection) were greatly expanded on days 14 and 40 after infection, followed by a loss of nearly 50% of these cells by day 60.