5.

Close-contact patches as an activation hypothesis in nanopores. (a) Sketch illustrating the hypothesis where microvilli are stabilized within nanopores, stabilizing “close contact” patches where TCR signaling proteins cluster, while the bulky CD45 phosphatases are excluded. Influence of MβCD and GsMTx4 on clustering within close contact sites (right). (b) STED image of a T cell stained for CD45 (magenta) and LCK (yellow), acquired within nanopores, showing cross sections of microvilli, which appear as ring-like structures. Scale bar: 1 μm. A close-up view of a single microvillus (white square) is also shown on the side. Scale bar: 0.1 μm.