The level of cytokines in the ex vivo infection of murine macrophages with Mycobacterium tuberculosis complex

: To study whether the genotype of a mycobacterial strain might affect the ability of macrophages (MP) to produce the key cytokines, we determined the synthesis of interferon-gamma (IFN-gamma), tumor necrosis factor-gamma (TNF-gamma), and interleukin-6 (IL-6) in the infection of murine MP with M. tuberculosis H37Rv and M. bovis BCG, the strains that belong to the same genetic group (M. tuberculosis complex) but are opposite in virulent properties. MP infection with a virulent and attenuated M. tuberculosis complex strain was shown to differently affect the synthesis of IFN-gamma, TNFaalpha-, and IL-6. MP infection with M. tuberculosis H37Rv activated the generation of IFN-gamma and that with M. bovis BCG substantially increased the levels of TFN-alpha and IL-6. The findings suggest that this model may be used to investigate the specific features of mycobacterial strains of various genotypic clusters with eukaryotic cells.