We then tested the reactivity of bulk T cells isolated from the spleens of the recipients against donor-derived DCs. As shown in Figure 4A , T cells derived from Flt3L/Rapa treated mice exhibited a significantly lower proliferative response against donor BALB/c DCs in MLR when compared with that of T cells derived from untreated, rGST-treated and PBS-treated recipients. Unexpectedly, a similar proliferation rate was noted in recipients treated with either Flt3L or Rapa alone as compared with that of recipients treated with Flt3L/Rapa. This result promoted us to further examine cytokine production in the culture supernatants by ELISA. Of Interestingly note, the production of IL-10 was significantly higher in the Flt3L/Rapa treated mice. More importantly, although T cells derived from Flt3L or Rapa treated mice showed similar potency for proliferation (Fig. 4A ), but their capacity for secretion of IL-10 was similar to those T cells from control mice (Fig. 4B ). Collectively, our data suggest that Flt3L/ Rapa treatment enhances IL-10 secretion which could favor the induction of T anergy.