Peripheral blood T Regulatory cell counts may not predict transplant rejection
- Equal contributors
1 Key Laboratory of Transplant Engineering and Immunology, Ministry of Health, West China Hospital, Sichuan University, Chengdu China
2 Technology Research and Development Center, China Tobacco Chuanyu Industrial Corporation. Chengdu China
3 Chinese Cochrane Centre, Chinese Evidence-Based Medicine Centre. Chengdu China
BMC Immunology 2010, 11:40 doi:10.1186/1471-2172-11-40Published: 15 July 2010
Recent evidence shows that allograft survival rates show a positive correlation with the number of circulating T regulatory cells (Tregs). This study investigated both the number and the cytokine profiles exhibited by Foxp3+ Tregs in blood, spleen and lymph nodes of Lewis rat recipients of BN rat cardiac allografts after a single-dose of Rapamycin (RAPA).
Rats were divided into three groups: control group (containing healthy control and acute rejection group), and recipients treated with a single dose of RAPA on either Day 1 (1D group)or Day 3 (3D group) post-transplant. We analyzed the number of Foxp3+Tregs and the expression of Foxp3 and cytokines in the peripheral blood and the peripheral lymphoid tissues. No difference was found in the numbers of circulating Foxp3+ Tregs between these three groups. RAPA administration significantly increased Foxp3 expression in peripheral lymphoid tissues after a single dose of RAPA on Day 3 post-transplant. Foxp3+Tregs inhibited the activity of effector T cells (Teff) via the secretion of TGF-β1.
The number of Tregs in the recipient's blood may not be a good predictor of transplant rejection. Foxp3+Tregs inhibit the activity of Teff cells mainly in the peripheral lymphoid tissues.