In what may be a step toward curing diabetes, researchers report successfully transplanting insulin-producing cells between unrelated mice by tricking the immune system into accepting the foreign tissue.
Dr. Aldo A. Rossini, director of diabetes care at the University of Massachusetts Medical Center in Worcester, Mass., said the technique showed insulin-producing pancreatic islets could be transplanted without using anti-rejection drugs, which carry the risk of serious side effects.
A report on the study will be published Tuesday in the Proceedings of the National Academy of Sciences.
Rossini said the transplant technique involves shots of white blood cells, made from the donor mice, and injections of a substance called anti-CD40L. Together, these shots train the immune system of the receiving mouse to tolerate the transplanted pancreatic islets.
In the reported study, Rossini and his team used mice that had been turned into diabetics by disabling the pancreatic cells that produce insulin. The mice were then divided into two groups, some receiving the shots of the white blood cells and the anti-CD40L.
For those getting the shots, 37 of 40 mice showed no sign of rejecting the insulin-producing cells that had been transplanted from an unrelated type of mouse. The transplanted cells made insulin and arrested the diabetes in the mice.
A control group of mice that received transplanted cells, but without the white blood cells or antibody shots, quickly rejected the transplants. Their immune systems killed the transplanted cells - and the mice received none of the insulin.
An incomplete study showed the technique works so well that islets from rats were successfully transplanted into mice, Rossini said. The diabetes in the mice was stopped by the transplanted rat cells, he said.
Sara King, director of research for the Juvenile Diabetes Foundation, said transplantation of pancreatic islets is “one of the most provocative approaches to curing diabetes, but a major obstacle is the problem of rejection.” She said that by overcoming the rejection problem, Rossini’s work “is an important advance toward an eventual cure.”
Rossini cautioned that the transplant work is still in an early stage and has been tested thoroughly only on rodents. He said many questions need to be answered in other experiments before the technique can be tested on humans. This process may take years, he said.