A new experimental therapy to treat diabetes, which involves transplanting embryonic pig stem cells into the diseased tissue, is currently being researched. Experiments have been done on primates, but the results that have been obtained indicate that in the future the same technique could be applied to human beings. For many years, pig organs have been considered the most best match to be used in human transplants, but strong immune reactions and powerful combinations of anti-rejection drugs have always represented an important obstacle in their clinical use.
A study published in the Proceedings of the National Academy of Sciences demonstrates that embryonic tissue from pigs, if transplanted, can form a complete pancreas in the host organism. Yair Reisner and his colleagues say that using an embryonic pancreas in place of an adult pancreas in a transplant encourages the development of the organ and the network of blood vessels that supply and nourish the organ, helping reduce the intensity of the immune response against foreign tissues.
For now, researchers have transplanted embryonic pig pancreases into two groups of monkeys with diabetes, which caused the death of the animals in the first group. An analysis demonstrated that the dose of drugs administered to the first group to suppress the immune response was too high and was lowered in the second group of monkeys. This group survived for almost one year after the transplant.
The key result of this study, say researchers, is that they now understand that the monkeys that received the transplants did not need any insulin for at least four months after the operation. Differently from adult pancreatic tissues, embryonic Langerhans cells have a greater ability to tolerate stress and to regenerate.