FIG. 2.

Time course of secretion of cytokines after exposure to STF. Human PBMC were cultured in the absence (media) or presence of STF (4 μg/ml) or TT (2 μg/ml). Culture supernatants were collected at various time points, and the concentrations of TNF-α, IL-1β, IL-10, and IFN-γ were determined. These results are representative of those observed with cells obtained from three different individuals immunized orally with the attenuated Ty21a S. typhi strain.