Interspecies Transplant Possible, May Lead to Better Diabetes Treatment

For the first time, researchers have been able to transplant insulin producing cells between two species, paving way for use of animal cells in transplants.

The research was conducted by scientists at Northwestern Medicine, where islets cells that produce insulin were successfully transplanted from rats to mice. Islet cells contain beta cells that produce insulin, essential to break sugar in the body.

The method of transplantation, implantation or infusion of animal cells with human cells is called Xenotransplantation.

"This is the first time that an interspecies transplant of islet cells has been achieved for an indefinite period of time without the use of immunosuppressive drugs," said Stephen Miller, co-senior author of the study, according to a news release. "It's a big step forward."

Researchers' plan is to successfully transplant islet cells from pigs to humans.                         

In the study, researchers were able to coax the mice' immune system to accept the new islet cells. They found that the rat islet cells produced insulin in rats for about 300 days. Interestingly, the procedure didn't involve suppression of the immune system via drugs, which is known to cause other side-effects.

Researchers suppressed the immune system of the mice by injecting dead splenocytes, from the rat liver into the mice. This led the T cells recognize the rat islet cells and not attack them. Also, researchers gave the study mice B-cell depleting antibodies during the procedure. The study team found that the B-cells didn't kill the islet cells even after their levels were increased after the transplant. 

People with diabetes type-1 have difficulty breaking down sugar in body as their immune system keeps attacking the cells that make the hormone insulin (beta cells) needed to control sugar levels. High blood sugar for long periods of time can lead to serious damage to heart, eyes, kidneys and nerves. People diagnosed with type-1 diabetes need to take insulin for the rest of their lives.

Patients with uncontrollable form of diabetes type-1 are given treatments that involve transplanting islet cells from deceased donors. However, the waiting list for the transplant is long as there aren't many donors. Using animal cells for transplant could save many people, but there are many drawbacks to the procedure, including high risk of organ rejection by the patient's body.