IL-10 neutralizationTo determine the role of IL-10 and TGFb in the suppression of antigen ?specific T cell cytokine responses in PTB, we stimulated whole blood from PTB individuals with PPD in the presence of neutralizing antibodies for IL-10 or TGFb or isotype controls for 72 h and measured levels of IFNc, IL-4 and IL-17A. As shown in Figure 6A, neutralization or blockade of IL-10 resulted in significanly increased PPD-stimulated production of IFNc (GM of 6.68 ng/ml with anti-IL-10 Ab vs. 0.592 ng/ml with isotype control), IL-4 (GM of 0.D significantly lower levels of IL-17A 1516647 and IL-17F in response to PPD [IL-17A (GM of 0.115 in PTB; 0.857 in TBL and 1.37 in LTB) and IL-17F (GM of 0.055 in PTB; 0.256 in TBL and 0.133 in LTB)], ESAT-6 [IL-17A (GM of 0.118 in PTB; 1.13 in TBL and 2.08 in LTB) and IL-17F (GM of 0.052 in PTB; 0.148 in TBL and 0.124 in LTB)], CFP-10 [IL-17A (GM of 0.126 in PTB; 1.20 in TBL and 2.15 in LTB) and IL-17F (GM of 0.050 in PTB; 0.185 in TBL and 0.228 in LTB)] but not anti-CD3 (Figure 4D) in comparison to both TBL and LTB individuals. Interestingly, antigen ?induced IL-22 production was not significantly different between the 3 groups. Similarly, TBL individuals did not exhibit any significant differences in Type 17 cytokine production in comparison to LTB individuals. Thus, PTB (but not TBL) is characterized by a decreased antigen-specific Type 17 cytokine response.PTB is associated with decreased production of antigenspecific Type 1 cytokinesTo determine the impact of PTB, TBL or LTB on mycobacterial antigen-specific Type 1 cytokine responses, we measured levels of antigen ?specific IFNc, TNFa and IL-2. As shown in Figures 2A, B, C, PTB individuals exhibited significantly lower levels of IFNc, TNFa and IL-2 in response to PPD [IFNc: (geometric mean [GM] of 0.445 ng/ml in PTB; 4.20 ng/ml in TBL and 13.9 ng/ml in LTB), TNFa (GM of 0.796 in PTB; 4.41 in TBL and 11.2 in LTB), IL-2 (GM of 0.234 in PTB; 1.56 in TBL and 3.99 in LTB)]; ESAT-6 [IFNc (GM of 0.519 in PTB; 7.96 in TBL and 23.6 in LTB), TNFa (GM of 1.73 in PTB; 12.7 in TBL and 28.9 in LTB), IL-2 (GM of 0.354 in PTB; 0.612 in TBL and 1.77 in LTB)]; CFP-10 [IFNc (GM of 0.517 in PTB; 7.28 in TBL and 21.9 in LTB), TNFa (GM of 1.49 in PTB; 14.0 in TBL and 25.1 in LTB), IL-2 (GM of 0.372 in PTB; 0.918 in TBL and 1.32 in LTB)] but not anti-CD3 (Figure 2D) in comparison to both TBL and LTB individuals. Those with TBL exhibited significantly lower levels of IFNc, TNFa and IL-2 in response to PPD and significantly lower levels of IFNc only in response to ESAT-6 and CFP-10 in comparison to LTB individuals. Thus, active TB (both PTB and TBL) is characterized by adecreased mycobacterial antigen-specific Type 1 cytokine response.PTB is not associated with significant differences in the production of immunoregulatory cytokinesTo determine the impact of active or latent infection or extrapulmonary dissemination on mycobacterial antigen-specific immunoregulatory cytokine responses, we measured antigen ?specific levels of IL-10 15755315 and TGFb. As shown in Figure 5A, PTB individuals did not exhibit any significant difference in IL-10 production in response to PPD, ESAT-6, CFP-10 or anti-CD3 in comparison to both TBL and LTB individuals. Similarly, PTB individuals did not exhibit any significant difference in TGFb production in response to PPD, ESAT-6, CFP-10 or anti-CD3 in comparison to TBL and LTB individuals (Figure 5B).Suppression of Type 1, 2 and 17 cytokines in PTB is overcome by IL-10 neutralizationTo determine the role of IL-10 and TGFb in the suppression of antigen ?specific T cell cytokine responses in PTB, we 
stimulated whole blood from PTB individuals with PPD in the presence of neutralizing antibodies for IL-10 or TGFb or isotype controls for 72 h and measured levels of IFNc, IL-4 and IL-17A. As shown in Figure 6A, neutralization or blockade of IL-10 resulted in significanly increased PPD-stimulated production of IFNc (GM of 6.68 ng/ml with anti-IL-10 Ab vs. 0.592 ng/ml with isotype control), IL-4 (GM of 0.