Side-chain theory

Paul Ehrlich's side- chain theory is a theory of antibody formation and a forerunner of today's selection theories of immune defense. It justified on the assumption that each cell has protein-containing substances and a series of side-chains or receptors that receive nutrients and certain toxic substances. These side chains of cells (blood cells) fit to the chemical groups of the invading toxins, which are now propagated and released into the blood, where they act as an anti- toxin. The foreign body bind for the key - lock principle. Ehrlich received for this theory the 1908 Nobel Prize for Medicine.

The emergence of the theory

Paul Ehrlich examined the specific immune defense of the body and assumed that foreign substances or infectious agents or their toxins dock (toxins ) in certain cells of the body. In the course of his research, he developed the theory that these exogenous substances have chain-like molecular structures (antigens ) that correspond to the similar " side chains " of cells' like a lock and key " and are thereby bound by them. He suspected that these specific side chains that were unusable due to the permanent connection with the antigen produced new to spare in a but then excessive reaction of the cell and released as free "antibody" into the blood would ( antibodies), and so the humoral immunity guaranteed. Later, however, noted Ehrlich and other researchers that for the neutralization of toxins or infectious agents often more antibodies are needed and that only their interaction is responsible for immunity. Ehrlich then dealt intensively with the receptors and found, in contrast to its original assumption that all body cells could produce antibodies out that this is only true for the B- lymphocytes. Honest recognized that the particular antigen, various structures are present, it is divided into haptophore and toxophore groups, causing the first bonding and the latter being responsible for the pathogenicity. Related, he discovered that Serumkomplementfaktoren attract phagocytic cells of the immune system scavenger cells (macrophages ). This provides the basis for the modern immunology were created.

Ehrlich was awarded the 1908 together with Ilya Ilyich Mechnikov, the discoverer of phagocytosis, the Nobel Prize for these findings. Also on other immune cells have been found later antibody-like receptors. This is Paul Ehrlich's basic assumption of the receptor- regulated immune responses, although some improvements are still valid.