To determine whether the growth inhibition of M. tb in monocyte-T cell co-cultures is accompanied by increased production of IL-12, IL-2 and IFN-γ, we quantified the levels of these cytokines in the cell free-supernatants from co-cultures of M. tb-infected monocytes and T cells (from healthy subjects and individuals with HIV infection) by ELISA (Figure 4). This evidence concerns the gene IFNG and HIV infectious disease.