Homing of CFSE-labeled antigen-specific CD4(+)CD25(+) regulatory T cells in islets transplantation

Objective: To observe the distribution and proliferation of the antigen-specific CD4(+)CD25(+) regulatory T (Treg ) cells and investigate the potential mechanism of antigen-specific CD4(+)CD25(+) regulatory T cells on the suppression of rejection for allogenetic islet transplantation in vivo.

Methods: Antigen-specific CD4(+)CD25(+) Treg cells were generated by the addition of multiple intravenous injections of ICR mice splenocytes in vivo. After labeled by CFSE, 8x10(5) antigen-specific Treg cells were injected via tail vein with islets transplantation. Homing and distribution of antigen-specific CD4(+)CD25(+) Treg cells were investigated by flow cytometric analysis and immunofluorescence.

Results: In vivo, the mean survival time of recipients with islets and antigen-specific CD4(+)CD25(+) Treg cells were (34.57+/-17.15) days, whereas transplanted islets without Treg treatment survived (10.6+/-1.82) days in control mice. The transferred antigen-specific CD4(+)CD25(+) Treg cells were mainly resident in pancreatic node and mesenteric node.

Conclusions: Allogeneic antigen-specific CD4(+)CD25(+) Treg cells prolong islet graft survival, and draining lymphoid tissue play a key role in the immune response.