Figure 4.

Chitosan promotes NK cell survival in the presence of DCs. (A) Flow cytometric analysis for Annexin V and 7-AAD staining in NK cells treated with different concentrations of chitosan for 48 hours in the presence of DCs. Quantification of the percentages of live (Annexin V^neg/7-AAD^neg) and late apoptotic (Annexin V^pos/7-AAD^pos) NK cells following treatment with varying doses of chitosan. (B) Flow cytometric analysis for Annexin V and 7-AAD staining in NK cells treated with different concentrations of chitosan for 48 hours in the presence of DCs and in the presence or absence of a blocking antibody against IL-15. Quantification of the percentages of live (Annexin V^neg/7-AAD^neg) and late apoptotic (Annexin V^pos/7-AAD^pos) NK cells in the presence or absence of chitosan (10 mg/L) and/or anti-IL-15 blocking antibody. Data in A and B were analyzed by Student's t test and shown as mean ± SEM. n = 3. ***, P < 0.001; **, P < 0.01. (C) Immunoblot of lysates from NK cells treated with different concentrations of chitosan using antibodies against cleaved-PARP, cleaved-caspase-3, and β-Actin (control). Data shown are representative of three donors with similar data.