exogenous antigen definition
Endogenous vs Exogenous Antigens. Any molecule or substance that reacts to a product of a specific immune response and stimulates antibody generation is considered as an antigen.The antibody generation by an antigen is called antigenicity of that particular molecule.Antigens can be either a protein or a polysaccharide.he vast majority of antigens are exogenous antigens. They are introduced into the body from outside via various infections agents such as bacteria, viruses, fungi, protozoa, helminthes etc., or environmental substances such as dust mites, foodstuff, pollen etc. by inhalation, ingestion, or injection.