What are MHC markers important for in the immune system?

MHC markers, or Major Histocompatibility Complex markers, play a crucial role in the immune system by marking 'self' cells to avoid attacks. These proteins are found on the surface of most cells in the body and serve as identifiers that communicate to immune cells that those cells belong to the body and are not foreign invaders.

When immune cells, particularly T cells, encounter MHC markers, they assess whether the presented antigens represent self or non-self material. If the MHC presents a 'self' antigen, the T cells are generally inhibited from launching an immune response, which helps prevent the immune system from attacking the body's own tissues—a phenomenon that can lead to autoimmune diseases. On the other hand, if the MHC markers present foreign antigens, it signals for an immune response to eliminate those pathogens.

This ability to differentiate self from non-self is essential for maintaining the body's health and preventing unnecessary immune responses against one's own cells. Therefore, the function of MHC markers is integral to the proper functioning of the immune response and immune tolerance.