Achievement of graft tolerance and withdrawal of chronic immunosuppression is still the main goal in transplant immunology. The One Study is a European FP7 founded clinical trial where different types of ex vivo generated/expanded regulatory cells are infused in living donors kidney transplant recipients with the ultimate goal of minimizing/discontinuing immunosuppression. Our Institute will take part to The One Study by infusing T Regulatory Type 1 (Tr1) cells.
Peripheral blood mononuclear cells (PBMCs) isolated from peripheral blood of patients with chronic kidney disease (CKD) and healthy controls (HC), buffy coats and leukapheresis samples of healthy blood donors were collected. Donor-specific Tr1 cells were generated following the standard protocol developed in our lab (Bacchetta et al., Haematologica 2011) or with the novel CD4+ protocol. Briefly, PBMCs or immune-magnetically selected CD4+ T cells were co-cultured with dendritic cells (DCs) generated in the presence of IL-10 (named DC-10) for 10 days. Cell anergy was evaluated by re-stimulating Tr1 cells with donor-derived mature DC (mDC).
Tr1 cells generated from CKD patients produce IL-10 in a donor-specific manner, and anergy negatively correlates with IFN production. Tr1 cells generated from PBMCs of CKD were less anergic as compared to those generated from HC; on the contrary, Tr1 cells generated from CD4+ Tcells were as anergic as those generated from HC.
These data support the use of a new CD4+-based protocol for the generation of highly anergic Tr1 cells to be used in The One Study.
