Researchers at the University of Montreal Hospital Research Centre have discovered a cellular structure that could potentially revolutionize organ transplantation. Mélanie Dieudé, PhD, and Marie-Josée Hébert, MD, identified apoptotic exosome-like vesicles, which, when injected into mice, stimulate autoantibody production and increase the risk of graft rejection after transplantation. They also identified a novel concept: The transplanted organ “talks” to the immune system. As Dr. Hébert explains, “It’s not only the immune system of the recipient of the organ that sees the organ as foreign, the organ shouts to the immune system ‘I may be detrimental to you.’ This starts a feud between the immune system and the recipient.” This feud may end in rejection of the graft.

How to interrupt this feud? Dr. Dieudé and Dr. Hébert have identified a way to block the enzyme activity of apoptotic exosome-like vesicles through the administration of bortezomib, a proteasome inhibitor currently approved for the treatment of certain bone marrow cancers. Results are preliminary and phase 3 trials are underway, but this research suggests new ways to anticipate and control organ rejection after transplantation. Click here to review the article published in Science Translational Magazine.