TABLE 5.

IL-12 potentiates Mycobacterium-specific IFN-γ production

T-cell line	IFN-γ production a (pg/ml) with:
	MIM			rAg85B		IL-12 productionb (pg/ml) with:
	− IL-12	+ IL-12	+ anti– IL-12	− IL-12	+ IL-12	MIM	MIM + PBMCb
Mtb.187	<5	174	<5	ND	ND	7	<5
Mtb.191	65	184	63	ND	ND	<5	10
Mtb.184	34	599	50	97	206	30	17
Mtb.193	82	397	141	22	77	7	14
Mtb.186	129	1,510	ND	12	394	<5	<5

^aMtb T-cell lines were generated by stimulating normal PBMC with MIM in the absence (−) or presence (+) of IL-12 (1 ng/ml) or neutralizing antibody to IL-12 (100 μg). They were challenged in vitro with MIM or rAg85B-pulsed normal macrophages for 3 days. Supernatants were harvested at 72 h, and IFN-γ production was determined by an ELISA. ND, not determined. 

^bMature macrophages (from donors 187, 191, 184, 193, and 186) were infected with MIM (ratio, 20:1) or mock infected (data not shown). After 2 days, autologous naive PBMC were cocultured with MIM. Supernatants were harvested at 48 h and tested for IL-12 p70 by an ELISA.