22-10-2012, 03:42 PM
Antigen Processing and Presentation
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Antigen Processing and Presentation
Antigen processing refers to the ability of APCs to break down a protein antigen into peptides and to associate those peptides with MHC molecules
Antigen presentation is the process of displaying peptide antigens associated with MHC molecules to a T cell
Antigen Recognition by T Cells
T cells recognize linear peptides not whole proteins.
T cells only recognize epitopes when they are complexed to MHC molecules.
Therefore protein antigens must be processed and presented by other cells to be recognized by T cells.
This process is referred to as antigen processing and presentation.
In general CD8+ T cells recognize endogenous antigens and CD4+ T cells recognize exogenous antigens.
MHC molecules bind multiple peptides, however each T cell only recognizes one peptide.