Figure 4. a, b.

(a) CD4+ T cells were co-cultured with irradiated TGF-β1+/− KO mouse splenocytes for 3, 5, or 7 d, and proliferative responses were measured. The CD4+ T cell proliferation increased when harvested from the MSC-untreated mice on POD 7 (p<0.001 vs. all the other grafts grouped together). (b) CD8+ T cells were co-cultured with irradiated TGF-β1+/− KO mouse splenocytes in the presence of IL-2 after 3, 5, or 7 d. Live cells were collected, and the cytotoxic activity against B12 cells was assessed. There was an increased cytotoxic T lymphocyte activity of T cells from the MSC-untreated mice on POD 7 (p<0.001 vs. all of the other grafts grouped together).