Vidcast:  https://www.instagram.com/p/DSBPxskDW56/

Organ transplantation is a miracle for those with failing kidneys, hearts, or livers.  With those transplants comes the need for lifelong immunosuppression and the risk of infection as well as graft failure due to an immune attack.

With the hope of eliminating the need for this immunosuppression, Stanford transplant immunologists and developmental biologists have developed a transplantation technique employing an induced hybrid or chimeric immune system in the recipient. They now publish their studies using this system to successfully transplant insulin-producing pancreatic islet cells in diabetic mice.

The researchers performed the dual transplantation of the pancreatic islet cells but also white cell-forming stem cells from the genetically-mismatched donor. To permit the stem cells to escape rejection and develop the hybrid immune system, the recipient animals received a one-time pretreatment with low dose radiation and several immunosuppressive agents.

All of the animals so treated developed the hybrid-chimeric immune system that allowed them to remain tolerant and fully accept the islet cell transplants without further immunosuppression and with excellent islet cell insulin production. The recipients’ new chimeric immune system did not attack their own cells or organs, so-called graft versus host disease.

This is such a ground-breaking development, let’s review it with a diagram from the published paper. Pancreatic islet cells and bone marrow cells from the un-related donor are harvested and transplanted into the diabetic recipient whose immune system has been temporarily weakened with low dose radiation and anti-T cell antibodies.  The recipient’s immune system becomes permanently tolerant to the donor’s cells and the transplanted islet cells remain functional and produce insulin curing the diabetes. This hybrid immune system does not attack the recipients cells either.

This induction of a hybrid-chimeric immune system such that the transplant recipient’s new immune system is similar enough to the donors so that it fails to reject the transplant opens the door for not only islet cell transplantation in humans but also immunosuppression-free heart, liver, and kidney transplantation.

https://www.sciencedaily.com/releases/2025/11/251126095018.htm

https://www.jci.org/articles/view/190034

#transplantation #diabetes #hybrid #stemcell #immunosuppression