TABLE 6.

Growth of BCG in IFN-γ-, LPS-, and BSO-treated macrophages from iNOS^−/− mice^a

Treatment	Colony count (mean)b				Pc
	Mean		SE
	1 h	72 h	1 h	72 h
None	1,238	2,847	304	688	0.1800
IFN-γ + LPS	1,403	355	286	54.47	0.0025
IFN-γ + LPS + BSO	616	1,011	194	213	0.1906

^aThioglycolate (3%) was injected into the peritoneal cavities of iNOS^−/− mice. Four days after injection, animals were anesthetized with isoflurane. Peritoneal cavities were washed with ice-cold RPMI to recover peritoneal macrophages. Peritoneal macrophages were infected with BCG at an MOI of 10:1. At 2 h after infection, unphagocytosed organisms were removed. BCG-infected macrophages were maintained in RPMI containing 10% fetal bovine serum, containing 10% fetal bovine serum plus IFN-γ (100 U/ml) and LPS (1 μg/ml), or containing IFN-γ (100 U/ml), LPS (1 μg/ml), and BSO (500 μM).

^bInfected macrophage cultures were terminated at 1 h and 5 days to determine the intracellular viability of BCG in unstimulated and stimulated cultures. Intracellular viability of BCG was determined by colony counts.

^cCalculated with the Statview program.