Figure 3 PD-1/PD-L1 pathway inhibited CD4+T cell differentiation into Treg cells. (A) The expression of PD1 in the co-culture system of myofibroblasts and CD4+ T cells increased significantly. GAPDH protein was used as negative standard. (B) After blocking PD1, the numbers of Treg cells increased in the co-culture system. (C) When myofibroblasts were blocked by PD1, the numbers of Treg cells in the co-culture system increased. Blocking PD1 in CD4+ T cells did not significantly change the proportion of Treg cells. (D) After blocking PDL1 in the myofibroblasts, the numbers of Treg cells in the co-culture system also increased.