FIGURE 6.

Selective inhibition of Malt1 protease activity in Wt peripheral T cells does not affect Treg but attenuates Th17 differentiation in an alloresponse. Whole T cells (TC) were purified from spleen and lymph nodes of wild-type (Wt) and Malt-ko B6 mice. 1 × 10⁵ CFSE-labeled responder T cells were cultured with 0.2 × 10⁵ allogeneic B6D2 DC for 6 days. Wt T cells cultured alone in medium were used as controls (Wt Nil). As comparison, Wt T cells were treated with either 200 μM Malt1 tetrapeptide inhibitor z-VRPR-fmk (MI), or 100 ng/ml cyclosporine A (CsA). (A) CFSE dilutions of dividing CD4⁺ (upper gate) and CD8⁺ (lower gate) T cells on day 6 of culture. Frequency of (B) Foxp3⁺CD25⁺, (C) ROR-γt⁺, (D) IL-17⁺ and (E) IFN-y⁺ CD4⁺ T cells (gated on CD4⁺), respectively. (F) Phosphorylated (p)-Stat3 and p-Stat5 expression (gated on CD4⁺) analyzed by flow cytometry after short restimulation of T cells with anti-CD3/CD28-coated beads at 37° for 20 min. All culture conditions were performed in triplicate. Flow cytometry dot-plots and histograms data are representative of one out of three independent experiments.