Table I. Effect of TGF-β and IL-12 on iNKT cell IFN-γ and IL-4 production.

	Control	rhTGF-β1	rhIL-12	rhTGF-β1 and rhIL-12
IFN-γ (pg/ml)	1701 ± 1341	1093 ± 1035	5430 ± 2450	2929 ± 1844
IL-4 (pg/ml)	903 ± 547	675 ± 435	1019 ± 493	825 ± 544

iNKT cell lines (1 × 10⁵) were co-cultured with α-GalCer-loaded mature moDC (5 × 10⁴; total volume of 500μl) for 24 h in the presence or absence of 10 ng/ml rhIL-12p70 and 10 ng/ml rhTGF-β1 as indicated. Supernatants were harvested and analyzed for the production of IFN-γ and IL-4. Data represent mean ± SD of five donors. IFN-γ production was significantly increased by rhIL-12 ( p = 0.01) and significantly decreased by the addition of rhTGF-β1 to control ( p = 0.03) and IL-12 ( p = 0.03). IL-4 production was not significantly changed by rhIL-12 ( p = 0.26). IL-4 production was significantly decreased when rhTGF-β1 was added to control ( p = 0.03) but not when rhTGF-β1 was added to rhIL-12 ( p = 0.17).