Human apoptotic cells generated by extracorporal photopheresis modulate allogeneic immune response

The induction of a specific and sustainable tolerance is a major issue in organ transplantation. The discovery of the immunosuppressive properties of apoptotic cells in animal models has paved the way for their use in human transplantation. In this work, we aimed to define a stable, reproducible and clinically compatible production procedure of human apoptotic cells (Apo-cells). Using a clinically approved extracorporeal photopheresis technique, we have produced and characterized phenotypically and functionally human apoptotic cells. These Apo-cells have immunosuppressive properties attested in vitro and in vivo in NSG mice by their capacity to modulate an allogeneic response following both a direct and an indirect antigen presentation. These results brought the rational for the use of Apo-cells in tolerance induction protocol for organ transplantation.