World-first discovery: Insulin gives an extra boost to the immune system

University Health Network researchers, Dr. Sue Tsai and Dr. Daniel Winer.

Toronto General Hospital Research Institute (TGHRI) scientists have demonstrated, for the first time, how insulin boosts the immune system to improve its ability to fight infection. Their findings were published today in the prestigious scientific journal Cell Metabolism.

The paper, titled, “Insulin receptor mediated stimulation boosts T cell immunity during inflammation and infection,” was a collaborative effort by first author Dr. Sue Tsai, postdoctoral fellow, and senior authors, Dr. Daniel Winer, Anatomical Pathologist, University Health Network and Scientist, TGHRI and Dr. Shawn Winer, Anatomical Pathologist, St. Michael’s Hospital.

To date, much work has been done looking at the role of insulin in organs and tissues such as the liver, muscle and fat, to understand regulation of blood sugar and how the body metabolizes or turns it into energy. However, little is known about how insulin impacts the immune system.

“We have identified one of metabolism’s most popular hormones, specifically the insulin signaling pathway, as a driver of immune system function,” says Dr. Dan Winer. “Our work characterizes the role of this signaling pathway in immune cells, mainly T cells, opening up avenues in the future to better regulate the immune system.”

This new research helps to explain why insulin-resistant individuals, such as people living with or at high risk of developing Type 2 diabetes, may have weakened immune responses and increased susceptibility to developing severe infections.

The insulin signaling pathway that the scientists discovered could provide new targets for treatment and help to reduce complications in people living with diabetes. This discovery also has potential impact beyond diabetes as it could be harnessed to either boost the immune response to create vaccines, or dampen it to help heal inflammatory illnesses such as arthritis, ulcerative colitis and Crohn’s disease.

Donors to Toronto General & Western Hospital Foundation played an important role in advancing this research, along with the Canadian Institutes of Health Research, Diabetes Canada, the J.P. Bickell Foundation, and the Banting and Best Diabetes Centre at the University of Toronto.