CD8A and infection: To approximate the physiological number of endogenous precursors [33], we adoptively transferred 5 × 103 naïve Thy1.1+ DbGP33–41 specific TCR-tg CD8+ T cells (referred to as P14 cells) into Thy1.2+ C57BL/6 mice 1–2 days before infection with 2 × 106 PFU of LCMV Armstrong or clone 13.