An interspecies transplant of islets, the cells that produce insulin, has been reportedly achieved for the first time — and without the use of immunosuppressive drugs. It’s the first step on the long road to the ultimate goal of being able to transplant the insulin-producing cells from pigs into people with type 1 diabetes.
The number of cases of type 1 diabetes greatly outstrips the number of available human donors to contribute transplantable islet cells.
But pig islets also produce insulin that can be used safely by humans with type 1 diabetes to control their blood sugar.
However, in the past, interspecies transplantation of cells has carried with it a significant risk that the recipient species’ body will simply rejected the transplanted cells.
Researchers from Northwestern University announced the successful interspecies transplant on Friday. The effort is described in a paper published online today in the American Diabetes Association journal Diabetes.
In a statement from Northwestern, study co-senior author Stephen Miller said:
“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. It’s a big step forward.”
They tested the new technique by transplanting rat islets into mice bodies. The method involved temporarily killing off certain immune and white blood cells that would normally attack the transplanted cells as foreign bodies. However, the immune cells were eventually allowed to recover so that the animals could live a normal life with a healthy immune system.
The method seemed to work, allowing the mice to adjust to the interspecies transplant without rejecting the islets and to live out a normal life of 300 days.
The Northwestern researchers said that solving the transplant rejection problem from rats to mice is likely easier than from pigs to humans. But proving that an interspecies transplant is possible at all was a vital first step.