TABLE 1.

Induction of cytokines in C3H/OuJ macrophages stimulated with E. coli LPS or with P. gingivalis LPS^a

Cytokine	Level (pg/ml)b
	Medium only	E. coli K235 LPS	P. gingivalis LPS
TNF-α (6 h)	<23	12,713 ± 3,456	757 ± 62
IL-12 p40 + p70
6 h	<15	2,701 ± 127	150 ± 32
24 h	<15	7,065 ± 438	328 ± 25
IL-12 p70
6 h	<15	143 ± 2	<15
24 h	<15	279 ± 20	<15

^aC3H/OuJ macrophages were cultured at a final density of 4 × 10⁶/well in six-well plates and treated with 2 ml of medium only or medium containing 100 ng of E. coli K235 LPS or P. gingivalis LPS per ml. Supernatants were harvested at 6 or 24 h and assayed by ELISA for TNF-α, total IL-12 (IL-12 p40 plus p70), or bioactive IL-12 p70 as described previously (29). 

^bArithmetic mean ± standard deviation of duplicate samples.