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Exogenous antigens are antigens that have entered the body from the outside, for example, by inhalation, ingestion or injection. By endocytosis or phagocytosis, exogenous antigens are taken into the antigen-presenting cells (APCs) and processed into fragments.
People also ask, what is the difference between endogenous and exogenous antigens?
The difference is that the peptides originate from different sources – endogenous, or intracellular, for MHC class I; and exogenous, or extracellular for MHC class II. Endogenous antigens can also be presented by MHC class II when they are degraded through autophagy.
In this manner, what is exogenous antigen processing?
The exogenous pathway is utilized by specialized antigen-presenting cells to present peptides derived from proteins that the cell has endocytosed. The peptides are presented on MHC class II molecules. Proteins are endocytosed and degraded by acid-dependent proteases in endosomes; this process takes about an hour.
Antigens are generally proteins. But they can be lipids, carbohydrates or nucleic acids. Antigens can be of three types – Exogenous, endogenous and autoantigens. Antigens can also be foreign bodies that stimulate the immune system of the body.