T cell antigen-receptor signal transduction.

During the past year, major progress has been made in understanding proximal TCR signal-transduction events. Cbl has been identified as a negative regulator of kinases from the ZAP-70/Syk family. Studies on LAT, SLP-76, Itk and Vav have revealed their role in the activation of Ras and phospholipase-Cgamma1-Ca2+ signalling pathways. TCR-induced cytoskeletal changes involve signalling through SLP-76-Vav-Nck to activate effectors of the Rho-family of GTPases. Finally, glycolipid-enriched microdomains play a crucial role in T cell activation.