Increased frequency of CD4⁺CD25⁺Foxp3⁺Treg cells positively correlates with bacillary load in the sputum of PTB patients and inversely with <i>Mtb.</i> antigen specific cytokines response in PTB patients.

<p>Percentage of Treg cells from freshly isolated PBMCs of PTB patients correlated with the bacillary load among the patients. (<b>A</b>) CD4⁺CD25⁺Foxp3⁺ Treg cells frequencies were significantly higher among patients with high bacillary load (3+) than those with lower bacillary load (1+). Statistical analyses of values between cell population from 3⁺ (n = 8), 2⁺ (n = 6) and 1⁺ (n = 7) bacillary load were performed with the nonparametric Mann Whitney U test for unpaired data. (<b>B</b>). PBMCs isolated from PTB patients were cultured for 24 hrs with <i>Mtb.</i> antigen (WCL). Cultured cells were washed and surface stained with anti-CD4 followed by IFN-γ and IL-4 intracellular staining. Statistical analyses of ratio of IFN-γ and IL-4 producing CD4 T cells from PTB patients and HCs were performed with the nonparametric Mann Whitney U test, two-tailed for unpaired data. Each symbol represents a single individual. (<b>C</b>) Inverse relationship between CD4⁺CD25⁺Foxp3⁺ Treg cells and <i>Mtb.</i> antigen specific IFN-γ and IL-4 ratio from PTB patients (n = 21; correlation statistics were analyzed using the Spearman correlation).