T-cell cytotoxic function relies on the cooperation between the highly specific T-cell receptor (TCR) and integrins of co-stimulatory molecule at the immunological synapse. Super resolution 3D STED (Leica SP8, 775 nm) is used to study the oorganisation of these molecules during the activation of immune response. Image cytometer (ImageSteam) allows the quantification of molecules recruited at the immunological synapse in a large number of cells.