Researchers at the University of California, San Francisco (UCSF) are conducting a Phase I clinical trial using a patient’s own immune cells to halt or reverse the course of type 1 diabetes for those recently diagnosed with the disease. The trial represents the first time that these cells, called regulatory T cells, or Tregs, will be used to treat an autoimmune disease.
After years of honing in on the cause of type 1 diabetes, scientists now know that insulin-producing beta cells are ultimately destroyed by one arm of the immune system, namely T cells. There are different types of T cells, and diabetes results from a functional imbalance between T cells that mistakenly destroy beta cells and Tregs, which try to prevent that from happening.
“Everyone has some of these destructive T cells floating around,” says Stephen E. Gitelman, M.D., one of the lead investigators of the study and a professor of clinical pediatrics at UCSF. “But normally these protective Tregs keep them in check and prevent them from mistakenly attacking one’s own tissues. For people with type 1 diabetes, this balance has been lost.”
The idea for the present trial started with work in the laboratory of Jeffrey Bluestone, Ph.D., at UCSF. His group showed that in an animal model of type 1 diabetes, a brief treatment with Tregs taken and purified from the animal itself can fundamentally change the immune system, and lead to a lasting diabetes cure.
Building off of that work, Bluestone and his colleagues developed a way to apply this work in humans. The new protocol involved isolating and purifying Tregs from people’s own blood, and then growing a large batch of these cells. After two weeks, the Tregs often multiply 1000-fold or more, providing enough Tregs to test if such a treatment is a safe and effective way to treat diabetes. In this trial, the UCSF researchers plan to infuse the Tregs back into the affected individual, and evaluate whether the additional Tregs can tame destructive T cells from further attacking the body’s own insulin-producing beta cells.
The study has already begun to screen potential participants and will eventually enroll a total of 14 eligible subjects ages 18 and older and within two years from diagnosis. Each participant will receive a single dose of their own Tregs and will then be followed over five years to assess the safety and effectiveness of the Treg therapy. “For all these years, we have been looking outside of the patient to fight the autoimmune response that leads to type 1 diabetes,” says Dr. Gitelman. “But now, the answer may lie within the patients themselves.”
Further details about this clinical trial are available at: www.ClinicalTrials.gov