Transplanted pancreatic precursor cells can be protected from the immune system if they are encapsulated in polytetrafluorethylene (PTFE); experiments on mice conducted by American scientists have revealed.
The finding, made by researchers from Burnham Institute for Medical Research (Burnham) and the University of California San Diego (UC San Diego) School of Medicine, suggests a new approach to treating Type 1 diabetes.
During the study, the researchers observed that the upon being transplanted, the precursor cells mature into functional beta cells that are glucose-responsive and control blood sugar levels.
They also found that using precursor cells, instead of more committed beta cells, enhanced the cell transplant's chances of success.
"The results exceeded our expectations," said Dr. Pamela Itkin-Ansari, 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," she added.
For their study, the researchers used two different mouse models. They transplanted mouse islet cells into other mice to demonstrate that the cells were protected from the immune system when encapsulated in PTFE.
The team later transplanted human cells encased in PTFE into immunodeficient mice to study the viability and function of both mature beta cells and precursor cells inside the device.
The researchers found that by using precursor cells that had not completely differentiated, the transplanted cells could regenerate into fully functional beta cells.
Itkin-Ansari says that this has important implications for how stem cell-derived tissue should be transplanted in the future.
Type 1 diabetes results from an autoimmune response wherein the body attacks and kills insulin producing beta cells in the pancreas.
One of the challenges of cell transplantation therapy to treat diabetes is the need for long term immunosuppression, which carries health risks.
Transplanting beta cells in a protective device could alleviate the need to use immunosuppressive drugs.
A research article on the study has been published in the journal Transplantation.