Figure 2.

Induction of NK cell IFN-γ production by chitosan occurs via activating DCs to produce IL-12 and IL-15. (A) RT-PCR and flow cytometric analysis of TLR-4 (TLR4) expression in DCs cultured in the presence or absence of chitosan (10 mg/L). (B) RT-PCR and flow cytometric analysis of IL-12 (IL12B) and IL-15 (IL15) expression in DCs cultured in the presence or absence of chitosan (10 mg/L). (C) Flow cytometric analysis and quantification of IFN-γ⁺ NK cells when co-cultured with DCs and treated with or without chitosan (10 mg/L) in the presence of antibodies against IL-12 and/or IL-15. The left panel shows the data from one representative donor and summary data are shown on the right. (D) ELISA analysis of IFN-γ in the supernatants of NK cells co-cultured with DCs and treated with or without chitosan (10 mg/L) in the presence or absence of IL-12 and/or IL-15. Fig. 2A-D were analyzed by Student's t test and shown as mean ± SEM. n = 3–5. **, P < 0.01; *, P < 0.05; ns, P > 0.05. (E) Immunoblot of lysates from NK cells treated with different concentrations of chitosan using antibodies against STAT4, p-STAT4, NFκB-p65, p-NFκB-p65, and β-Actin (control). Data shown are representative of three donors with similar data.