HVEM is required for optimal accumulation of virus-specific effector CD8 T cells directed against subdominant but not dominant VACV epitopes.

<p>Groups of C57BL/6 WT or HVEM-deficient (HVEM<sup>−/−</sup>) mice were infected i.p. with the indicated inoculums of VACV-WR. (A) On day 7-post infection, IFN-γ-secreting CD8 cells were assessed by intracellular cytokine staining after stimulation with the indicated VACV peptides (B8R, A3L, A8R, A23R, or B2R). Total numbers ± SEM of CD8<sup>+</sup>CD62L<sub>low</sub>IFN-γ<sup>+</sup> T cells per spleen from four individual mice. *<i>p</i><0.05 (WT vs HVEM<sup>−/−</sup>). Similar results were obtained in three separate experiments. Representative plots of IFN-γ staining in gated CD8 T cells after infection with 3×10<sup>4</sup> PFU VACV-WR (B) or 3×10<sup>2</sup> PFU VACV-WR (C). Numbers indicate the percentage of CD8<sup>+</sup>IFN-γ- positive cells. Similar results were obtained in three separate experiments.</p>