Review of Antigen-Presentation Systems

MHC (major histocompatibility complex) molecules are involved in presenting antigens on the cell surface. In humans, MHC is called H L A (human leukocyte antigen). MHC classes 1 and 2 differ in their functions.

MHC

Cell involved

Molecule bound

Elicited action

MHC class 1

Virus infected cell

A piece of viral protein being synthesized

Cytotoxic T cells bind via TCR and CD8 molecules and kill the cell

MHC class 2

Dendritic cell Macrophage B cell

Antigen from a microbe taken into the cell

Helper T cells bind via TCR and CD4 molecules and become activated