FIG. 4.
RNase protection analysis for T-cell and macrophage markers and cytokine RNA in organs of perforin-deficient thymic expressors or nonexpressors. Groups of two or three mice were infected with LCMV at 105 PFU intraperitoneally, and organs were harvested and RNA was extracted for RNase protection analysis on day 40 to 60 postinfection (see Materials and Methods). Results were compared to those observed in organs derived from age-matched, nontransgenic uninfected controls (Con.). Results from one representative animal per group are shown. Note that organs from perforin-deficient mice show signs of chronic immune system activation; i.e., CD8 cells are found abundantly, and large amounts of IFN-γ and TNF-α are produced (Table 4). Virus was found in all areas of the spleen of perforin-deficient mice (data not shown). Perforin-deficient thymic NP expressors showed much less IFN-γ production and CD8 infiltration than did nonexpressing littermates.