Fig. 2.

Virus-specific CD8⁺ T cells donate their antigen specificity to CD8⁺ T cells of unrelated specificity in vivo, a process that can control an ECTV infection. Enriched splenic CD8⁺ T cells (Fig. S1) from ECTV-immune B6.SJL or B6.Prf^−/− mice and IAV-immune B6.SJL mice were adoptively transferred into recipient B6.WT mice 24 h after infection with 5 × 10⁴ PFU of virulent ECTV. Groups of mice received 10⁷ cells of any one T cell population or a mixture of 0.5 × 10⁷ B6.Prf^−/− ECTV-immune and 0.5 × 10⁷ B6.SJL IAV-immune cells. (A) Splenic viral titers 4 days after infection and 3 days after cell transfer. *, P < 0.05; NS, not significant. (B) CTL activity of unsorted splenocytes against ECTV-infected MC57G fibrosarcoma target cells. (C) CTL activity, against the same ECTV-infected targets, of CD8⁺ T cells FACS separated based on their CD45 allotypes.