Involvement of natural killer cells in XXXX production by spleen cells after stimulation with Mycobacterium bovis BCG. Study of the mechanism of the different abilities of viable and killed BCG.

@entity3542 @entity842 @entity3692
Viable and killed BCG were compared for the ability to induce @entity842 (NO) production in normal spleen cells and peritoneal exudate macrophages. Stimulation of spleen cells with viable BCG resulted in a strong expression of inducible NO synthase followed by an enhanced production of @entity3542 . However, those responses were not induced after stimulation with killed BCG or when macrophages were stimulated with killed and viable BCG. The same level of TNF-alpha mRNA expression was observed in reverse transcription-PCR after stimulation of spleen cells with viable and killed BCG. However, @entity3692 production was induced only when spleen cells were stimulated with viable BCG. Concurrent stimulation of @entity3692 with either viable or killed BCG resulted in a strong @entity3542 production by macrophages. Neutralization of @entity3692 and TNF-alpha caused a complete inhibition of @entity3542 production. Furthermore, anti-asialo GM1 Ab plus complement treatment abolished @entity3692 production after stimulation with viable BCG, indicating that the NK cell was the major source of @entity3692 , and its production was triggered only by stimulation with viable BCG. The present study showed that the ability of viable BCG to induce NO production is superior to that of killed BCG, and both @entity3692 and TNF-alpha are essential for BCG-induced NO production by spleen cells. NK cells appeared to be important as a source of @entity3692 , and the insufficient NO induction by killed BCG was due to the inability to induce @entity3692 from NK cells.
