TNF and infection: In the present study, transcript levels in rabbit lungs were measured at 3 hours post-infection, whereas protein and transcript levels of TNF-α and CCL-2 were determined at 7, 14, 21, 28 and 60 days in infected mice or 24, 48, 72 and 96 hours in Mtb-infected human PBMC, in other published reports [14,48,49].