Figure 5: Exosome-pulsed DCs facilitate antigen specific CD8+ T cell differentiation. A-C. Human peripheral DCs were prepared from PBMC as described in the text. The DCs were pulsed with SEB/Derp1-carrying exosomes at the concentrations as indicated in panels A-C. Peripheral CD3+ CD25- T cells were isolated from PBMC. The DCs were cultured with CD3+ CD25- T cells at a ratio of 1:10 for 3 rounds (3 days/round). Cells were collected at the end of culture and analyzed by flow cytometry. A, bars indicate the frequency of CD8+ T cells. B-C, bars indicate the levels of granzyme B (B) and porforin (C) in culture medium. D. The cell culture procedures in panel D were the same as that in A-C except the CD3+ CD8+ T cells were labeled with CFSE prior to the culture. The specific antigen, Derp1, was added to the culture in the last culture round. The cells were collected at the end of culture and analyzed by CFSE-dilution assay. The bars indicate the frequency of proliferated CD8+ T cells. The data were presented as mean ± SD from 3 experiments. *, p<0.05, compared with the "0 ng" group in panels A-C and the saline group in panel D.