Fig. 1.

HY and P14 CD8 T cells remain phenotypically naïve during LCMV and PV infections, respectively. CFSE-labeled HY transgenic CD8 T cells were adoptively transferred into naïve congenic female recipients, which were infected with 5 × 10⁴ PFU LCMV i.p. the following day. Similarly, CFSE-labeled P14 transgenic CD8 T cells were adoptively transferred into naïve congenic male recipients, which were infected with 1.5 × 10⁷ PFU PV i.p. the following day. At days 0 (naïve) and 5 (d5) postinfection, splenocytes were stained for the activation markers shown. Host polyclonal CD8 T cells and TCR-transgenic CD8 T cells were gated, and representative histograms from the same individual mice are overlaid.