Seminar

Exosomes and Dendritic Cells: A Potential Treatment in Transplantation?

Francesc Borras, PhD.

The acquisition of allo-specific tolerance is relevant in transplantation. Dendritic cells (DC) are the inducers of the immune response to donor MHC molecules, thus promoting graft rejection. However, DCs are also responsible for the induction of peripheral immune tolerance.

In several animal models of allogeneic transplantation, graft tolerance has been established by using in vitro differentiated tolerogenic DCs. In humans, several potential sources of alloantigen, including apoptotic cells and exosomes, have been postulated. Exosomes abundantly express MHC antigens and show a relatively stable composition, which is probably an advantage compared to other sources. Dendritic cells are able to capture exosomes in vivo and in vitro, and to present exosome-derived alloantigen. Our group is using plasma or short-term cell culture derived exosomes as alloantigens to promote alloantigen-specific tolerance in an in vivo renal transplantation model.