Table 3.

IL-12 and IFN-γ Synthesis by Cells Harvested from iNOS ko and C57BL/6 Mice at 5 d after i.p. Challenge with T. gondii

						Peritoneal exudate						Spleen						Serum
						Mean ± SE		n		Range		Mean ± SE		n		Range		Mean ± SE		n		Range
IL-12p40		C57BL/6		bkg		1.4 ± 0.5		6		0–3.5		5.4 ± 1.8		7		2.3–12.7		17.1 ± 3.9		3		15.6–23.2
				STAg		10.9 ± 3.3		6		0.3–19.5		35.4 ± 6.0		7		20.7–53.5
		iNOS ko		bkg		1.9 ± 0.4		6		1.2–4.1		10.3 ± 2.8		9		3.6–17.6		19.5 ± 9		3		13.7–27.3
				STAg		11.9 ± 4.3		6		4.3 ± 25.9		56.4 ± 9.1		9		38.0–93.6
IFN-γ		C57BL/6		bkg		0.1 ± 0.06		6		0–0.3		0.6 ± 0.5		7		0–3.1		5.1 ± 0.5		3		4.4–5.8
				STAg		1.0 ± 0.3		6		0.2–2.1		8.3 ± 2.1		7		1.3–17.9
		iNOS ko		bkg		6.0 ± 2.9		6		0.3–15.4		1.1 ± 0.7		9		0–3.9		3.4 ± 0.3		3		2.9–3.8
				STAg		8.2 ± 4.0		6		0.8–2.13		10.4 ± 2.7		9		1.8–19.2

Mice were infected with 20 ME49 cysts each, killed 5 d later, and then peritoneal and spleen cells were isolated. Cell suspensions from each animal were cultured for 72 h in medium alone or in the presence of STAG (5 μg/ml). Supernatants were then assayed by ELISA for IL-12p40 and IFN-γ as described in Materials and Methods. The data shown are pooled from three experiments employing the number of animals indicated.