Fig. 2. Effects of metformin on the MHC class II-restricted presentation of exogenous OVA. (A) BM-DCs and (B) peritoneal macrophages were cultured with the indicated amounts of metformin for 2 hrs, and then combined with OVA-microspheres. After 6 hrs incubation, the cells were washed and fixed, and the amounts of OVA peptides presented on MHC class II molecules were assessed using OVA-specific CD4 T cell hybridoma, DOBW. The amounts of IL-2 produced from OVA-specific CD4 T cells were assayed by a commercial IL-2 ELISA kit. ^†p<0.01 vs. untreated group based on Student’s t-test. **p<0.01 vs. OVA only based on Student’s t-test.