Figure 3. Kinetics of M. tuberculosis–specific CD4⁺ and CD8⁺ T cells producing IFN-γ in PBMCs and BAL.

PBMCs (blue circles) and BAL (red circles) were stimulated with CW and ESAT-6/CFP-10 peptide pools, and IFN-γ production by CD4⁺ and CD8⁺ T cells was assessed by ICS and flow cytometry. IFN-γ–producing CD4⁺ (A and B) and CD8⁺ (C and D) T cells at indicated time points (weeks) post–M. tuberculosis infection in macaques (n = 6) with LTBI. CW-specific CD4⁺ (A) and CD8⁺ (C) T cell frequencies and ESAT-6/CFP-10–specific CD4⁺ (B) and CD8⁺ (D) T cell frequencies in PBMCs and BAL are shown. Horizontal lines indicate the mean with SEM. Wilcoxon’s matched-pairs signed rank test was used to compare the frequencies of IFN-γ–producing CD4⁺ and CD8⁺ T cells between BAL and PBMCs.