Assembly of the immunological synapse for T cells and NK cells

Recent three-dimensional fluorescence imaging of immune surveillance by different lymphocytes indicates common processes in the assembly of immunological synapses. After proteins accumulate at intercellular contacts, they segregate into domains that can be subsequently organized. This is sometimes accompanied by signalling through lipid rafts before effector functions such as secretion. Segregation of some proteins can be spontaneous, such as at the inhibitory natural killer (NK) cell synapse, but protein clustering and organization can also be controlled by ATP-dependent cytoskeletal movements, such as during full T-cell activation. A complete understanding of the supramolecular chemistry at immunological synapses in living cells requires the application of new technologies such as fluorescence lifetime imaging.