Significant relief for people with type 1 diabetes could soon come in the form of a device made from a thermoplastic resin commonly used as a coating for cookware, gaskets, and hoses.
The device uses polytetrafluoroethylene to encase and protect transplanted pancreatic precursor cells from attacks by T-cells, the “soldiers” of the body’s immune system. By protecting the transplanted cells from T-cell assaults, the device could do away with the need for type 1 transplant patients to take long-term immunosuppressant drugs.
A study on mice conducted by the Burnham Institute for Medical Research and the University of California, San Diego, School of Medicine, both located in La Jolla, California, found that precursor cells encapsulated in the plastic device generated no response by the immune system.
The scientists originally thought that even though the T-cells would not be able to penetrate the protective casing, they would cluster around it like an army laying siege to a well-fortified town. Instead, T-cells ignored the intruder, indicating that the immune system was not even aware of the presence of the device.
Precursor cells are cells that have the potential to grow into cells that have more specific purposes-such as the production of insulin. The study found that such cells increased the likelihood of transplant success versus already formed pancreatic beta cells.
Although there have been many instances of successful transplantation of insulin-producing beta cells into animals and people with type 1 diabetes, the vexing problem is the inevitable immune system attack on the cells. Aside from the irony that type 1 diabetes is itself classified as an immune system disease, the long-term use of immunosuppressants to prevent attacks on the transplanted cells lowers patients’ resistance to other diseases.
The San Diego researchers, who published their findings in the online journal Transplantation, say that encapsulation in a protective coating offers a potential new approach to treating type 1 diabetes. Instead of virtually eliminating a patient’s immune system through heavy drugging, such devices could “hide” transplanted cells and offer a stealthy way to get them past the body’s sentries.