Bacterial infection primes CD8^lo cells in vivo. Purified CD8^lo cells were labeled with CFSE and injected into nonirradiated B6.Thy1.1 male recipients. At 24 hours after transfer, the mice were infected with LM or left uninfected. (A) The plots represent the CFSE and NKG2D profiles of gated CD8^lo T cells on day 5 in either uninfected (left) or LM-infected (right) mice. (B) Spleens from day-5 infected or uninfected mice were cultured with a Golgi inhibitor in the presence or absence of H-Y peptide (1 μM). After 6 hours of incubation, the cells were fixed and stained with anti-IFNγ, anti-H-Y TCR, and anti-CD8 mAbs. The dot plots depict the CFSE and IFNγ profiles of gated H-Y TCR⁺ CD8⁺ cells.