Jonathan Choy

Areas of interest

Control of immune responses that lead to transplant rejection

The immune system protects our body from infectious microbes and other harmful exposures but its misdirection to non-harmful targets can cause health challenges. In the setting of organ transplantation, which is a surgical procedure in which a failing organ is replaced with an operational one from another person, the immune system targets the newly transplanted organ and “rejects” it. This is a major challenge to the long-term success of organ transplantation as a medical procedure. We are studying how activation of the immune system towards transplanted organs is controlled in an attempt to develop ways to specifically prevent this activation. Main research projects are interested in 1) understanding how the gut microbiota, which are microbes that normally inhabit the intestinal tract of our bodies, affect immune responses that cause organ transplant rejection and 2) how bioactive carbohydrates on the cell surface of blood vessel cells controls immune activation and how they can be therapeutically added to blood vessels in transplanted organs to prevent rejection.

Nitric oxide production, signaling, and biology

Nitric oxide (NO) is a bioactive gas produced by some cells that controls many cell biological processes. Its production is important for physiological functions such as immune clearance of infectious microbes, function of blood vessels, and neurological development and its dysregulation contributes to diseases such as auto-inflammatory diseases, cancer, and cardiovascular disease. My laboratory is interested in understanding how NO effects cell signaling and how its production is controlled by enzymes called NO synthases.