Antigen: Learn about antigens

Learn about antigens. Get the antigen definition and learn about the types, functions, and types of tests in immunology. Antigen , substance that is capable of stimulating an immune response, specifically activating lymphocytes, which are the body’s infection-fighting white blood cells. In general, two main divisions of antigens are recognized: foreign antigens (or heteroantigens) and autoantigens (or self-antigens). An antigen is a molecule that can bind to an antibody or a T-cell receptor and trigger an immune response. Learn about the structure, function, and classification of antigens, as well as their role in vaccines, allergies, and autoimmune diseases. Antigen It is a substance usually protein in nature and sometimes polysaccharide, that generates a specific immune response and induces the formation of a specific antibody or specially sensitized T cells or both. Antigens are “targeted” by antibodies. An antigen may be a substance from the environment, such as chemicals, bacteria, viruses, or pollen or may also be from inside the body. In general, two main divisions of antigens are recognized: foreign antigens (or hetero-antigens) and ...