INTERLEUKIN-12 SECRETION BY MYCOBACTERIUM TUBERCULOSIS-INFECTED MACROPHAGES

Infection with Mycobacterium tuberculosis or phagocytosis of large lat ex beads induced interleukin-12 (IL-12) production in macrophages. In contrast, tumor necrosis factor (TNF) was produced only in response to M. tuberculosis infection, not after phagocytosis of later bends, Com parable results were obtained with cells from immunocompetent C57BL/6 and gamma interferon receptor-deficient mutant mice. Thus, phagocytosi s by mechanisms not specific for dl. tuberculosis was a sufficient tri gger for IL-12 secretion, emphasizing the central at role of this cyto kine in the initiation of anti-infective immunity.