TABLE 4.

Effect of IL-18 treatment in vitro on IFN-γ production by peritoneal cells from uninfected BALB/c mice treated with or without anti-asialo GM1 antibody

Expt and in vivo treatment	IFN-γ (ng/ml)a		Increase (fold)b
	IL-18(−)	IL-18(+)
1
Vehiclec	1.9	7.0	3.7
IL-18	0.7	0.7	1.0
2
NRSd + vehicle	1.1	11.5	10.5
NRS + IL-18	2.9	6.5	2.2
AGMe + vehicle	1.9	5.0	2.6
AGM + IL-18	<0.2	0.6	>3.0

^aPeritoneal cells were incubated in the presence or absence of IL-18 (1 ng/ml), and the culture supernatants were harvested 24 h later. IFN-γ in the supernatant pooled from duplicate or triplicate samples was measured by ELISA. 

^bIFN-γ amount after IL-18(+) treatment/IFN-γ amount after IL-18(−) treatment. 

^cThe vehicle or IL-18 (1 μg per mouse a day) was administered i.p. to mice for 3 days, and peritoneal cells were prepared 1 day after the last administration. 

^dNRS or anti-asialo GM1 antibody was injected i.p. into mice twice, 1 day each before and after the first administration of the vehicle or IL-18. 

^eAGM, anti-asialo GM1 antibody.