Table 1.

LPS-induced TNF production

Treatment	Serum TNF (ng/ml)
	TNF+/+	TNF+/−	TNF−/−
LPS (100 μg)	9.0  ± 0.6	3.0  ± 0.5*	0
C. parvum + LPS (10 μg)	1,500  ± 450	3,000  ± 1,500	0

Serum TNF levels 1.5 h after i.p. injection of LPS. C. parvum was injected 10 days before LPS. 

^*P < 0.05 compared with TNF^+/+ mice.