Immunological synapse

As immunological synapse (or supramolecular adhesion complex ( SMAC )) is known in the immunology the contact point, through the two cells of the immune system (. E.g., a leukocyte with an antigen presenting cell ) or an immune cell with a tissue cell contact each other. The name was coined based on the term neural synapse , but differs from it in essential points. Above all, the immunological in contrast to the neuronal synapse is a short-term, temporary phenomenon.

function

Receptors and adhesion molecules on cell surfaces are not bound to a specific location, but can move relatively freely within the cell membrane. When cells come into contact with one another, these molecules are specially arranged in the direction of the other cell. The concentration of receptors and cell adhesion molecules in one place on the cell membrane and of further signal molecules in the cytoplasm of the cell directly below the contact point enables important signals to be exchanged between cells.

Depending on the type of cells involved and the signal molecules, the transmission of information via the immunological synapse can lead to very different consequences for the cells involved, e.g. B. programmed cell death , phagocytosis of a cell, or increased proliferation .

structure

Recent research has shown that the immunological synapse can be divided into a central and a peripheral area:

• Central supramolecular activation cluster (cSMAC): This is where the receptors that are necessary for cell activation and are involved in specific signal transduction chains are concentrated .
• peripheral supramolecular activation cluster (pSMAC): This is where intercellular adhesion molecules ( ICAMs ) are concentrated . a. also have a mechanical function in the formation and maintenance of the synapse.

Occurrence

Immunological synapses are formed between cells of the immune system ( T lymphocytes , B lymphocytes , macrophages , natural killer cells ) and between immune cells and tissue cells.