FIG. 1.

Effect of exogenous TNF-α (A) and anti-TNF-α antibody (B) on IL-10 production. Vitamin D₃-treated THP-1 cells (10⁶/ml) were incubated with L-OspA (1 μg/ml) or LPS (1 μg/ml) in the presence or absence of various concentrations of human rTNF-α and anti-TNF-α antibody. After 48 h, IL-10 in cell supernatants was quantified by antibody-capture ELISA. The lower limit of detection of the ELISA was 15 pg/ml. Asterisks indicate significant differences from cells incubated with L-OspA and LPS alone (P < 0.05 to P < 0.0004). P values were calculated by use of Student's t test. Each bar represents the mean ± standard error of duplicate cultures. Data are representative of two separate experiments.