Fig 2. Ag85b-specific CD4⁺ T cells, but not TB10.4-specific CD8⁺ T cells, inhibit bacterial growth in vitro.

(a) Matched (H-2^b) or mismatched (H-2^k) macrophages were infected with H37Rv for 2 hours, and then, one day post-infection, T cells were added. Separately, TB10.4 or Ag85b peptide was added to Mtb-infected (H-2^b) macrophages, and then T cells were added. CFU were determined 4 days later. (b) C57BL/6 macrophages were infected with H37Rv as described above. The next day, TB10.4₄₋₁₁ peptide and Ag85b_240-254 peptide was added for 1 hour, indicated as “+,” to wells that would later receive TB10.4₄₋₁₁-specific CD8⁺ and P25 CD4⁺ T cells, respectively. Subsequently, unbound peptides were washed away and TB10Rg3, TB10RgP, TB10RgL, TB10RgR, or P25 T cells were added. CFUs were determined 4 days later. Results are representative of at least three experiments. Statistical testing was by one-way ANOVA, using the Dunnett posttest compared to d5. *, #, p<0.05; **, p<0.01; ***, p<0.005; ****, p<0.0001.