Exogenous Antigen Processing

Pathways of Antigen Processing

For an immune response to occur, B cells and T cells must recognize that a foreign antigen is present.
B cells can recognize and bind to antigens in lymph, interstitial fluid, or blood plasma
T cells only recognize fragments of antigenic proteins that are processed and presented in a certain way

In antigen processing, antigenic proteins are broken down into peptide fragments that associate with MHC molecules
The antigen–MHC complex is then inserted into the plasma membrane of a body cell
This process is called antigen presentation