Fig. 1.

Cytoskeletal remodeling and the immunological synapse. Schematic diagram showing IS initiation (top) and maturation (bottom) both from the side (right) and from the perspective of the APC (left). Radially symmetric spreading over the surface of the APC is driven by protrusive actin polymerization, accompanied by the formation of TCR microclusters (TCR-MC, red dots) in the plasma membrane. As the IS matures, retrograde flow of F-actin drives TCR-MCs into the cSMAC, while F-actin is reorganized into a peripheral ring known as the dSMAC. Integrins, for their part, cluster in the pSMAC. Concomitantly, the centrosome reorients to a position just beneath the center of the IS