Major histocompatibility complex (MHC)

A set of proteins on the surface of certain immune cells that influence the interaction of normal cells with immune cells. Antigen-presenting cells present digested antigens to T-cells through the MHC on their surface, which allows the T-cells to “see” the antigen and recognize it as foreign. The connection between the MHC and the receptor on the T-cell is the first signal (Signal 1) necessary to activate the T-cell to respond to a tumor and destroy it. [Patient Resource LLC]