FIG. 4.

IL-12p40 production by immature DCs stimulated with T. pallidum or the synthetic lipopeptide. XS52 cells were incubated with increasing amounts of either virulent treponemes (A) or a synthetic lipopeptide modeled after the 47-kDa membrane lipoprotein of T. pallidum (47-L) (B). Times examined are denoted in panel A. Cell supernatants were then assayed for cytokine production by capture ELISA. Neg, negative control (either TEx [A] or the 47 hexapeptide [B]) equivalent to the highest dose of stimulus, assayed after 24 h of incubation. Shown are the means ± standard errors of duplicate determinations from two (A) and three (B) independent experiments.