Indolamine 2, 3- dioxygenase (IDO) gene regulation in chlamydiae-infected monocytes and DCs. Monocytes and monocyte-derived DCs were infected with C. trachomatis serovars Ba, D and L2 (MOI-3) and mock control. IDO gene copy numbers was determined by isolating RNA at the indicated time points followed by real-time PCR as described in materials and methods. IDO fold change was normalized to 18S rRNA and determined by ddCt method with mock sample as reference gene. The mean of 3 independent experiments is shown and each experiment is pool of 2 donors. ***P < 0.001, **P < 0.01, *P < 0.05.