Figure 7
Chitin enhances OVA-induced airway eosinophilia by promoting Th2 cell activation dependent on augmentation of IL-33-induced IL-1β production by DCs. (a) BMDCs derived from C57BL/6-wild-type mice were cultured in the presence and absence of chitin, rIL-33 and rIL-33+ chitin for 24 h. The levels of IL-1β, IL-6 and TNF in the culture supernatants were assessed by ELISA. The data show the mean ± SE. Results are representative of similar results that were obtained in 3 independent experiments. 1-way ANOVA, *P < 0.05. (b) BMDCs from C57BL/6-wild-type and -Il1a−/−Il1b−/− mice were cultured in the presence and absence of chitin, IL-33 and IL-33+ chitin for 24 h. After washing, the BMDCs were co-cultured with CD4+ T cells from OTII mice in the presence of OVA peptides for 4 days. The levels of IL-13, IL-17 and IFN-γ in the culture supernatants were assessed by ELISA. Data are pooled from 3 independent experiments and shown as the mean ± SE. 1-way or 2-way ANOVA, *P < 0.05. (c) Naive II1rl1−/− mice were transplanted intranasally with DCs derived from C57BL/6-wild-type, - II1rl1−/− or Il1a−/−Il1b−/− mice. The mice were sensitized and challenged as in Fig. 1a. The number of eosinophils in the BALFs from these mice were determined. Data are pooled from 2–3 independent experiments and shown as the mean ± SE. 1-way ANOVA or Mann–Whitney U test, *P < 0.05.
