C57BL/6 mice were adoptively transferred with 5 × 10⁵ OT-I splenocytes 24 hours prior to vaccination by subcutaneous infection with either H37Rv-OVA or ΔsecA2-OVA. The animals were sacrificed 2, 4, 8, and 20 weeks after vaccination, and splenocytes were stained for 5-color fluorescence analysis using antibodies specific to Thy1.2, B220, CD62L, and CD44 plus SIINFEKL-loaded H-2K^b tetramer. (A) FACS analysis of total B220^– events among 1.5 × 10⁶ total lymphocytes, showing proportions of Thy1.2⁺ cells staining with tetramer. (B) Dot plots show expression of CD44 and CD62L on cells gated for tetramer staining as in A from representative mice sacrificed 2 weeks after infection with the indicated bacterial strains. The graphs show percentages of total B220^– lymphocytes staining with tetramer (Tet) and expressing either high or low levels of CD62L at each time point after vaccination. Filled squares represent ΔsecA2-vaccinated mice and open squares, H37Rv-OVA–vaccinated mice. Each symbol represents mean and SD for groups of 2 or 3 mice.