Cellular reaction to Mycobacterium avium complex (MAC) clinical isolates differing in hemolytic activity and virulence for C57BL/6 mice

The production of nitric oxide and tumor necrosis factor by murine macrophages infected with mycobacterial strains differing by hemolytic activity

In this study, we compared the secretion of nitric oxide (NO) and tumor necrosis factor (TNF-alpha) by murine macrophages infected in vitro with hemolytic or unhemolytic mycobacteria isolates. We observed that unhemolytic mycobacteria induced more intensive NO production by macrophages and were more susceptible to bactericidal effect of mononuclear phagocytes than hemolytic mycobacterial strains. In contrast, the high-virulence hemolytic isolates induced significantly stronger TNF-alpha production by infected macrophages than the low-virulence unhemolytic bacilli.