Figure 2.

Tracking VACV- and ECTV-reactive CD8⁺ T cell responses in B7.2^tg mice. B7^tg mice were inoculated i.n. with either PBS or either a sublethal dose of VACV or ECTV. After 4 weeks, primed mice were challenged i.n. with a lethal dose of the same virus (see “Materials and methods”). Spleens were harvested from mock (n = 2), VACV (n = 2) inoculated mice after 8–10 days post inoculation. CD8⁺ T cells were identified as CD8⁺ splenocytes after gating out dead cells and B220⁺ cells. Peptide-specific CD8⁺ T cells were identified with dual fluorochrome-labelled pB7.2 tetramers and binary encoding strategy (“Materials and methods”, and Fig. 1, and Figures S1, S2). Representative contour plots depicting common epitopes recognised by VACV and ECTV-reactive CD8⁺ T cells (A), novel epitopes F4L_6-14 and E9L_526-534 recognised by ECTV- but not VACV-reactive CD8⁺ T cells (B), and epitopes recognised by VACV- but not ECTV-reactive CD8⁺ T cells (C).