TGF-beta and MHC Expression

Major histocompatibility complex (MHC) molecules are essential to initiating T cell responses. MHC class I molecules are expressed on the surface of almost every cell in the body, excluding red blood cells. As such, expression of MHC I is tightly regulated to prevent unnecessary and damaging T cell responses and subsequent inflammation.

Transforming growth factor-beta (TGF-β) has been shown to downregulate MHC I surface expression on cells and in it’s absence, severe autoinflammatory diseases develop. Regulation of MHC I expression by TGF-b appears to be a fundamental to controlling inflammatory responses, but the cellular mechanism by which this happens is unknown.

I am currently investigating how TGF-β signaling regulates MHC I expression in mesenchymal stem cells. Understanding this molecular mechanism may lead to enhanced therapies that target TGF-β signaling in autoimmune diseases and cancer.

Flow cytometry histograms of MHC I surface expression on untreated (blue) and TGF-beta2-treated (red) MSCs. Figure by AKB.