FIG. 5.

A: A significant prolongation of islet allograft survival was shown in P2X7R^−/− C57BL/6 recipients of allogeneic BALB/c islets compared with wild-type recipients (n = 10, ***P < 0.0001 vs. wild-type untreated), and oATP treatment prolonged islet graft survival in P2X7R^−/− recipients (n = 5, §P < 0.05 vs. P2X7R^−/− untreated; ***P < 0.0001 vs. wild-type untreated). CD4⁺ and CD8⁺ T cells purified from splenocytes of wild-type (B and D, respectively) or P2X7R^−/− (C and E, respectively) C57BL/6 mice were challenged with anti-CD3 Ig and anti-CD28 Ig in the presence or absence of different concentrations of Bz-ATP and were tested for IFN-γ production in an ELISPOT assay. A preserved and efficient Bz-ATP response, despite the absence of P2X7R, was evident in P2X7R^−/− mice (C and E) and in wild-type mice (B and D) (n = 5, *P < 0.05, **P < 0.01 vs. Control). CD4⁺ T cells and CD8⁺ T cells were extracted from wild-type and P2X7R^−/− mice and were assessed for P2XRs expression. Higher levels of P2X1R and P2X4R were observed in P2X7R^−/− CD4⁺ (F) and CD8⁺ (G) T cells (n = 3, *P < 0.05, **P < 0.01 vs. wild-type) compared with wild-type.