The immunological synapse, also called the immune synapse, is the space between an antigen and an antibody that exists when these two molecules are linked. The antibody is able to deliver chemicals to the antigen through this synapse. These chemicals are used to set off a chain of chemical reactions that result in the destruction of the antigen.
There are two types of macromolecules, or large molecules, involved in the immunological synapse. One is an antibody, which is a type of immune cell called a lymphocyte, produced within the bodies of animals, including humans. The other molecule is known as an antigen. Antigens are considered hostile in living organisms, and can be a variety of different things, including proteins, bacteria and viruses, and harmless molecules, such as pollen or other allergens. Antibodies are attracted to antigens in order to destroy them and prevent sickness or infection in the organism.
The process of eliminating an antigen from an organism requires a number of steps. First, the antibody is attracted to an antigen. Once the two bind, the antibody releases chemicals, which travel through the immunological synapse until they reach the antigen. These molecules bind to the surface of the antigen, trigger a chain of chemical reactions and, eventually, destroy the foreign body. Once the lymphocyte releases a chemical onto the surface of the antigen, it moves away from the antigen, eliminating the immunological synapse.
The synapses between antigens and antibodies are similar to the those between nerve cells. The spaces involved are very small, often less than 1 micron (0.0001 cm). The antigen and antibody never actually touch while the antibody is sending chemicals across the immunological synapse. Once bonded to an antigen, an antibody releases powerful toxins, called cytokines. Binding closely to an antigen prevents the spread of cytokines to other parts of the body, where they could damage other cells.
Each antibody can only bind to one antigen at a time. It is possible, however, for multiple antibodies to attach to the same antigen. An antigen with multiple antibodies attached to it can be neutralized more quickly.
Initial research on the immunological synapse was completed by several different scientists. Abraham Kupfer discovered the synapse. Seeing that the space between the two macromolecules functioned in a similar fashion to the synapse between nerve cells, Michael Dustin named the immunological synapse. The discovery was announced in 1995.