Figure 1.

C57BL/6 CD4, CD8, and TNF-α knockout mice were vaccinated subcutaneously with 5 × 10⁴ CFU BCG, rested for 30 days and then infected with a low dose aerosol of M. tuberculosis H37Rv. CFU were determined at days 30 and 60 post-infection for the CD4^−/− and CD8^−/− mice and day 30 for the TNF-α KO mice (A). C57BL/6 mice vaccinated with 5 × 10⁴CFU BCG Pasteur 7 days before infection and the CFU determined 30 days after infection in lungs and spleens (B). The concentration of and TNF-α, IFN-γ, and IL-2 as determined by cytometric bead array (CBA) at day 30 post-infection when mice were vaccinated 7 and 14 days infection (C). IFNγ producing cells present in spleen as determined by ELISpot after stimulation with H37Rv Culture filtrate protein (CFP) after infection when mice are vaccinated 7 and 14 days before infection (D). Experiments were performed with N = 4–5 mice per group and are representative of multiple iterations. *p ≤ 0.05 **p ≤ 0.01, ***p ≤ 0.001, n.s., not significant.