Dissecting the diversity of host-derived antigens that could modulate MAIT immune surveillance

MR1 is an immune protein that shows vitamin B-related molecules to a special group of immune cells called MAIT cells. Most research has focused on vitamin B molecules made by bacteria, but much less is known about similar molecules made by the human body. In this thesis, I studied vitamin B2 (riboflavin) breakdown products that naturally occur in humans. I found that these molecules bind to MR1 and reduce how much MR1 reaches the cell surface, which in turn lowers MAIT cell activation. This suggests the body may use these molecules to calm immune responses.