The immunological synapse: a molecular machine controlling T cell activation.

The specialized junction between a T lymphocyte and an antigen-presenting cell, the immunological synapse, consists of a central cluster of T cell receptors surrounded by a ring of adhesion molecules. Immunological synapse formation is now shown to be an active and dynamic mechanism that allows T cells to distinguish potential antigenic ligands. initially, T cell receptor ligands were engaged in an outermost ring of the nascent synapse. Transport of these complexes into the central duster was dependent on T cell receptor-liigand interaction kinetics. Finally, formation of a stable central cluster at the heart of the synapse was a determinative event for T cell proliferation.