The Major Histocompatibility Complex in the Immune Response T cells evolved to deal with Ags inside the cell Viruses,bacteria and parasites that invade cells T cells use an Ag recognition system (TCR)that interacts with a fragment of an Ag presented on the surface of a cell bound to MHC gene product Major histocompatibility complex (MHC) Role is to bind to peptide fragments derived from protein Ags and then present them to T cells Binding of MHC molecules to peptide is selective-binds to only certain peptidesThe Major Histocompatibility Complex in the Immune Response ◼ T cells evolved to deal with Ags inside the cell ◼ Viruses, bacteria and parasites that invade cells ◼ T cells use an Ag recognition system (TCR) that interacts with a fragment of an Ag presented on the surface of a cell bound to MHC gene product ◼ Major histocompatibility complex (MHC) ◼ Role is to bind to peptide fragments derived from protein Ags and then present them to T cells ◼ Binding of MHC molecules to peptide is selective – binds to only certain peptides