Antigen Research

An antigen (Ag) is a molecule or molecular structure that can attach to a particular antibody or T-cell receptor in immunology. Antigens in the body can cause an immunological response. Originally, the term antigen referred to a material that produces antibodies. Proteins, peptides (amino acid chains), polysaccharides (chains of monosaccharides/simple sugars), lipids, nucleic acids, and other macromolecules are examples of antigens. Antigen receptors, such as antibodies and T-cell receptors, recognize antigens. Immune system cells produce a variety of antigen receptors, each of which is specific for a single antigen. Antigens that are important in practical immunology are mainly cellular or multicellular structures, rather than dispersed molecules. The antigen might come from within the body ("self-protein") or from the outside environment ("external antigen") ("non-self"). Due to negative selection of T cells in the thymus and B cells in the bone marrow, the immune system recognizes and kills "non-self" external antigens but does not normally react to self-protein. Vaccines are immunogenic antigens that are provided to a recipient with the goal of inducing the adaptive immune system's memory function to antigens of the pathogen invading that recipient. A common example is the seasonal influenza vaccine.

• Antigen Recognition & Response
• Antigen Labelling
• Antigen-Antibody Complex
• Vaccines