Immunological synapse

In immunology, an immunological synapse (or immune synapse) is the interface between an antigen-presenting cell and a lymphocyte. It was first discovered by Abraham Kupfer at the National Jewish Medical and Research Center in Denver and the term was coined by Michael Dustin at NYU who studied it in further detail. Daniel Davis and Jack Strominger showed structured immune synapses for a different lymphocyte, the Natural Killer cell, and published this around the same time. Abraham Kupfer first presented his findings during one of the Keystone symposia in 1995, when he showed three dimensional images of immune cells interacting with one another. Key molecules in the synapse are the T cell receptor and its counterpart the major histocompatibility complex (MHC). Also important are LFA-1, ICAM-1, CD28, and CD80/CD86.

The immune synapse is also known as the supramolecular activation cluster or SMAC. This structure is composed of concentric rings each containing a peculiar mix of molecules:
 * c-SMAC (central-SMAC) composed of θ isoform of protein kinase C, CD2, CD4, CD8, CD28, Lck, and Fyn.
 * p-SMAC (peripheral-SMAC) in the lymphocyte function-associated antigen-1 (LFA-1) and the cytoskeletal protein talin are clustered.
 * d-SMAC (distal-SMAC) enriched in CD43 and CD45 molecules.