In-frame TCR δ gene rearrangements play a critical role in the αβ/γδ T cell lineage decision

AbstractUsing a quantitative multiprobe Southern blot analysis, we demonstrate the surprising result that a significant proportion of αβ T cells and thymocytes retain T cell receptor δ locus sequences. A substantial portion of the retained δ locus is In a fully V-to-D-to-J rearranged configuration and 20% of these δ rearrangements are functional, significantly less than the 33% predicted for random gene rearrangements. Our observations are In conflict with the idea that αβ and γδ T cells derive from distinct precursors and suggest that commitment of a common precursor to the γδ lineage depends upon expression of a γδ T cell receptor. We propose that the Intrathymic T cell lineage decision is determined by a competition between the production of functional γδ and β-pre-T cell receptor complexes