FIG. 4.

A flagellin-EGFP fusion protein induces a proinflammatory response. Cultured APCs were incubated with a 10-μg/ml concentration of LPS, flagellin-EGFP, or EGFP or were left unstimulated (control). After 24 h the cell supernatants were collected and TNF-α and NO secretion were measured. (A) TNF-α production in each culture was measured by ELISA. (B) The same supernatants were used to analyze NO production, as measured by the Griess reaction. Data are the means of three independent experiments (performed with duplicates) (error bars, standard deviations). A significant (P ≤ 0.001 [Student's t test]) difference was found between the control group and the flagellin-EGFP group.