FIG 3.
Suppression of the cytokine response is not dependent on trophic form viability but is partially dependent on direct contact between trophic forms and dendritic cells. A total of 1 × 104 BMDCs (A to F) from BALB/cJ mice were incubated with 5 × 105 trophic forms, 5 × 105 heat-killed trophic forms, 5 × 105 sonicated trophic forms, 5 × 105 sonicated mixed P. murina organisms, and/or 10 μg/ml curdlan for 72 h. A total of 1 × 105 BMDCs (G to I) from BALB/cJ mice were incubated with 5 × 106 trophic forms and/or 10 μg/ml curdlan for 72 h in a Transwell culture plate. TNF-α, IL-1β, and IL-6 cytokine production, as indicated, was quantified by ELISA. Data represent the means ± standard deviations of three biological replicates per group and are representative of two separate experiments. One-way ANOVA with Student-Newman-Keuls post hoc tests was used to compare differences among the groups where the data were parametric (A to D and G to I): *, P ≤ 0.05; **, P ≤ 0.01; ***, P ≤ 0.001; n.s., not statistically significant. Kruskal-Wallis one-way ANOVA on ranks was used to compare differences among the groups where the data were nonparametric (E to F): *, P ≤ 0.05.