Figure 6.

Recipient M2-like macrophages induced by allogeneic donor CD4⁺CD25⁺ Tregs are dependent on arginase signaling pathways. (a) Phagocytosis of cRBCs by recipient macrophages of NOD-scid mice that received either the donor allogeneic CD4⁺CD25⁺ Tregs or the CD4⁺CD25⁺ Tregs and the arginase inhibitor, BEC, as detected by FCM. (b) The immunogenicity of the recipient macrophages was assessed by MLR. The proliferation of BALB/c CD4⁺ T cells induced by the allogeneic donor macrophages that were isolated from the NOD-scid mice that received no cells, CD4⁺CD25⁻ T cells, or CD4⁺CD25⁺ T cells either alone or in combination with BEC or BEC alone was determined by ³H-TdR incorporation in vitro. The data are the mean±s.d. (N=5). One representative of two independent experiments with similar results was shown. **P<0.01 compared among the indicated groups. BEC, S-(2-boronoethyl)-l-cysteine; cRBC, chicken red blood cell; FCM, flow cytometry; Treg, regulatory T cell.