Low-affinity T cells show reduced expression of CXCR3 and CD69 but increased gzmB at viral infection onset and contribute to early host protection. (A) Experimental layout of systemic LCMV-OVA infection. (B–D) Percent positive and normalized MFI of CD69 (B), CXCR3 (C), and GzmB (D) expression of OT-I and OT-3 T cells at 48 h p.i. Data are pooled from three to four independent experiments with a total of 9–12 mice per condition. Statistical significance was analyzed by paired Student’s t tests. (E) Experimental layout of local HSV_TOM-OVA skin infection. (F) Viral titers (as determined by PFU/gram of tissue) in skin tissue of Prf1-deficient mice that had not received T cells versus recipients of 5 × 10⁴ or 5 ×10⁵ OT-I and OT-3 T cells. Data are pooled from three independent experiments with five to nine mice total (for no cells and 5 × 10⁵ T cell recipients) and one experiment (5 × 10⁴ T cell recipients) with four mice. Each point represents one skin biopsy. Bars indicate the median. Statistical significance was analyzed using a Kruskal-Wallis test against no cells with Dunn’s posttest. *, P < 0.05; **, P < 0.01; ***, P < 0.001.