Table 3.

Levels of IL-12 measured by ELISA in culture supernatant from peritoneal macrophages cultured for 48 h with and without splenic NK cells and with and without 1 µg/ml LPS. Peritoneal macrophages from CD40−/– mice were also used, as well as splenic NK cells from CD154–/– and IFN-γ–/– mice

	MΦ (IL-12 pg/ml)	MΦ + ΝΚ (IL-12 pg/ml)	MΦ + LPS (IL-12 pg/ml)	MΦ + NK + LPS (IL-12 pg/ml)
WT	7·7 ± 1·0	7·7 ± 1·0	9·2 ± 0·9	6·0 ± 1·0
CD40–/–*	18·7 ± 3·0	15·2 ± 1·2	19·2 ± 1·9	15·0 ± 2·3
CD154–/–	13·0 ± 2·1	10·6 ± 0·4	11·8 ± 1·3	10·0 ± 2·6
IFNγ–/–	8·2 ± 2·5	10·2 ± 2·5	8·8 ± 2·2	3·0 ± 0·9¶

MΦ, peritoneal macrophages; NK, splenic NK cells; LPS, lipopolysaccharide; WT, wild type C57BL/6 mice; n = 6 per group, averaged repeated experiments

^*P < 0·05 WT versus CD40–/–.

^¶P < 0·05 MΦ + NK + LPS (IFN-γ–/–) versus MΦ or MΦ + NK or MΦ + LPS (IFN-γ–/–).