FIG. 2.

RNase protection analysis for T-cell and macrophage markers and cytokine RNA in organs of perforin-deficient and -competent thymic expressor or nonexpressor mice 7 days after LCMV infection. Groups of two to three mice were infected with LCMV at 10⁵ PFU intraperitoneally, and organs were harvested and RNA was extracted for RNase protection analysis on day 7 postinfection (see Materials and Methods). The results were compared to those observed in organs derived from age-matched, nontransgenic uninfected controls (Con.). Results for two representative animals per group are shown. Note that organs from perforin-deficient mice show a higher degree of immune system activation, since CD8⁺ cells are found more abundantly and larger amounts of IFN-γ and TNF-α are produced than in perforin-competent littermates (Table 4). Virus was found in all areas of the spleen of perforin-deficient mice (data not shown). No apparent differences were noted in thymic expressors and nonexpressors at this early stage postinfection (Table 4).