CD4 and tuberculosis: These results suggest that while cART reduces inflammation and TB reactivation — thereby decreasing M. tuberculosis antigen levels in the lung, resulting in a decrease in the overall Th1 CD4+ T cell population — the concurrent addition of the IDO inhibitor D1MT to cART results in significantly increased frequencies of CXCR3+CD4+ T cells in the BAL (airways), but not the lung, via mechanisms we do not understand.