FIGURE 7.

The Malt1 protease inhibitor mepazine regulates human T cells alloresponse in vitro and prolongs MHC-mismatched skin allograft survival in wild-type mice. PBMC from healthy donors were cultured alone (CTRL, left dot-plot panels) or co-cultured with irradiated allogeneic APC in a MLR, without or with the Malt1 inhibitor mepazine (MI, 3 μg/ml) (MLR and MLR + MI, middle panel and right panel dot-plots, respectively). Cells were harvested on day 7 of co-culture and analyzed by flow cytometry (A) CD4 (upper gate) and CD8 (lower gate) T cells proliferation was assessed by Ki-67 staining. Frequency of (B) CD4⁺CD25⁺CD127^– Foxp3⁺ T cells, (C) IFN-y⁺, (D) IL-2⁺ and (E) IL-17⁺ CD4⁺ (upper gate) and CD8⁺ (lower gate) T cells, respectively. All culture conditions were performed in triplicates. Flow cytometry data are representative of one out of three independent experiments. Means with SD, *P < 0.05. (F) Recipient wild-type (Wt) B6 mice received a MHC-mismatched B6D2 skin allograft, and were left untreated or received mepazine i.p. daily, starting the day before transplantation. Graft survival was monitored daily. MST, median survival time.