CD8A and infection: Using a combination of adoptive transfer of TCR retrogenic CD8+ T cells specific for TB10.44−11 (TB10Rg3 and TB10Rg4) [32] and TCRβ deep sequencing of tetramer+CD8+ T cells after vaccination and Mtb-challenge in intact mice, we track primary (1°, those expanding from naïve T cells) and secondary (2°, from memory precursors) TB10.4-specific CD8+ T cells during infection.