CD8A and infection: To better understand the stage-dependent activation of T cells in the DCLNs, we used MHC class I tetramer to track a parasite epitope (SIINFEKL)-specific population of CD8+ T cells generated in response to infection with Pru-OVA, a recombinant type II strain of T. gondii engineered to express a secreted, truncated form of the model antigen ovalbumin (Pepper et al., 2004; Figure 2—figure supplement 2b).