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

Groups of C57BL/6 WT or HVEM-deficient (HVEM^−/−) 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⁺CD62L_lowIFN-γ⁺ T cells per spleen from four individual mice. *p<0.05 (WT vs HVEM^−/−). Similar results were obtained in three separate experiments. Representative plots of IFN-γ staining in gated CD8 T cells after infection with 3×10⁴ PFU VACV-WR (B) or 3×10² PFU VACV-WR (C). Numbers indicate the percentage of CD8⁺IFN-γ- positive cells. Similar results were obtained in three separate experiments.