Scientists at Burnham Institute for Medical Research and the University of California San Diego may have overcome a major stumbling block in the long term treatment of Type 1 diabetes. Transplantation of pancreatic cells has been a difficult endeavor, partially because of the immune response by the body. To resolve the problem, the researchers have now wrapped pancreatic precursor cells in a membrane made of polytetrafluorethylene (PTFE), which is designed to keep them safe from being attacked by the immune system while allowing to function as normal insulin producing factories.
From a statement issued by Burnham Institute:
The team of scientists showed that after transplantation, the precursor cells mature into functional beta cells that are glucose-responsive and control blood sugar levels. Additionally, the study demonstrated that using precursor cells, instead of more committed beta cells, enhanced the cell transplant’s chances of success.
“The results exceeded our expectations,” said Pamela Itkin-Ansari, Ph.D., assistant adjunct professor at the UC San Diego School of Medicine and Burnham. “We thought that T-cells, although unable to penetrate the device, would cluster around it. But we found no evidence of an active immune response, suggesting that the cells in the device were invisible to the immune system.”
The investigators used two different mouse models in the study. The team transplanted mouse islet cells into other mice to demonstrate that the cells were protected from the immune system when encapsulated in PTFE. Human cells encased in PTFE were then transplanted into immunodeficient mice to study the viability and function of both mature beta cells and precursor cells inside the device. Itkin-Ansari’s team found that by using precursor cells that had not completely differentiated, the transplanted cells could regenerate into fully functional beta cells. This has important implications for how stem cell-derived tissue should be transplanted in the future.
Press release: Device Protects Transplanted Pancreatic Cells from the Immune System …
Image: Colour-enhanced electron micrograph of part of a pancreas cell showing the nucleus in blue, mitochondria in orange, a lysosome in red and rough endoplasmic reticulum in green. A nuclear pore is also visible in the nuclear membrane towards the right-hand end. The horizontal field width of the sample is 2.9 micrometres. Wellcome-Images