In several murine models of infection (Listeria monocytogenes, Mycobacterium tuberculosis or Salmonella typhi), CD8+ T cells are involved in the clearance of intracellular bacteria (Kägi et al., 1994; Harty and Bevant, 1995; Sztein et al., 1995; Stenger et al., 1997; Stenger et al., 1998; Levine et al., 2001). Here, CD8A is linked to infection.