Pig beta cells have been taught to deceive the immune system
Type 1 diabetes mellitus develops as a result of autoimmune destruction of insulin-producing beta cells of the pancreas. Currently, in order to maintain glucose metabolism, patients with this disease are forced to give themselves regular insulin injections throughout their lives.
The only alternative to substitution therapy is transplantation of a donor pancreas or isolated insulin-producing cells. However, the shortage of donor organs makes this procedure available only to isolated patients.
Pork insulin differs from human insulin by only one amino acid and has been used to treat patients with diabetes for several decades. The idea of transplantation of pancreas or beta cells of pigs to humans has also arisen for a long time, but so far it has not been possible to implement it due to the strongest immune rejection reaction caused by foreign tissue. Scientists tried to isolate pig beta cells using biologically inert material permeable to insulin, but this limited the supply of oxygen and nutrients to the cells, which significantly shortened their life expectancy in the recipient's body.
However, apparently, the problem of immunological incompatibility is solvable. In their latest work on humanized mice, researchers at Ludwig-Maximilian University of Munich, working under the guidance of Professors Eckhard Wolf and Jochen Seissle, demonstrated that beta cells of the pancreas of genetically modified pigs not only normalize insulin levels in the body, but also suppress the reaction from the immune system.
The secret of success lies in the fact that the beta cells of such pigs selectively express the LEA29Y protein, which effectively suppresses the activation of immune cells initiating the rejection reaction. When transplanted to mice with simulated diabetes and a "humanized" immune system, such cells were not rejected and restored the level of insulin in the body and, accordingly, glucose metabolism to normal values.
However, Professor Wolf warns that, despite promising results, there are no guarantees that this approach will work in the human body. In the near future, they plan to test its effectiveness on other transplant models.
Article by Nikolai Klymiuk et al. Xenografted Islet Cell Clusters From INSLEA29Y Transgenic Pigs Rescue Diabetes and Prevent Immune Rejection in Humanized Mice is published in the journal Diabetes.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on Ludwig-Maximilians-Universitat Munchen: Xenotransplantation as a therapy for type 1 diabetes.
27.04.2012