THE ROLE OF THE T-CELL RECEPTOR (TCR) IN ALPHA-BETA GAMMA-DELTA LINEAGE COMMITMENT - CLUES FROM INTRACELLULAR TCR STAINING/

Teens belong to two mutually exclusive lineages expressing either alph a beta or gamma delta T-cell receptors (TCR). Although alpha beta and gamma delta cells are known to share a common precursor the role of TC R rearrangement and specificity in the lineage commitment process is c ontroversial, instructive lineage commitment models endow the alpha be ta or gamma delta TCR with a deterministic role in lineage choice, whe reas separate lineage models invoke TCR-independent lineage commitment followed by TCR-dependent selection and maturation of alpha beta and gamma delta cells. Here we review the published data pertaining to the role of the TCR in alpha beta/gamma delta lineage commitment and prov ide some additional information obtained from recent intracellular TCR staining studies. We conclude that a variant of the separate lineage model is best able to accommodate all of the available experimental re sults.