FIG. 6.

S. mutans (S.m.) stimulates high and P. endodontalis (P.e.) stimulates low levels of production of TNF-α. PBMC were stimulated by the indicated ratios of bacteria to PBMC. Supernatants were collected after 24 h and analyzed by ELISA for TNF-α. The results are representative of three experiments. Each data point is the mean of triplicate samples. By one-way analysis of variance with Duncan’s post hoc test, bacterial stimulation significantly increased TNF-α production compared to unstimulated controls (C) at ratios of 1, 10, and 100 (P < 0.05). Unstimulated PBMC secreted undetectable levels (<10 pg/ml) of TNF-α.