TCRs alive on the periphery

Keeping T cell receptors (TCRs) away from the center of the immunological synapse boosts stimulatory stignals, based on work from Kaspar Mossman, Gabriele Campi, Jay Groves (University of California, Berkeley, CA), and Michael Dustin (New York University, New York, NY).

The immunological synapse—the cell–cell junction between a T cell and antigen-presenting cell (APC)—looks like a bull's eye, with a central cluster of TCRs and their bound antigen–MHC ligands surrounded by a ring of adhesion molecules and their ligands. Active TCR clusters form at the periphery but then move toward the center, where they stop signaling.

To determine whether this change of locale is necessary for TCR shutdown, the group blocked the inward transport. They first replaced the APC with a supported lipid bilayer containing antigen–MHC and...