Use of variable human Vδ genes to create functional T cell receptor α chain transcripts

Abstract

Previous studies of the human T cell receptor δ genes identified five commonly used V_δ segments distinct from any of the known V_α genes. To define better the relationship between the T cell receptor δ and α repertoires we amplified cDNA obtained by polyclonally activated lymphocytes with a common 3′ antisense Cα‐specific primer and with five different 5′ sense Vδ family‐specific primers. Amplified products were detected in staphylococcal enterotoxin C2, staphylococcal enterotoxin E, phytohemagglutinin, concanavalin A, anti‐CD3 and anti‐Vβ8‐activated cells, although each cell population expressed a selective pattern of Vδ genes. Sequence analysis revealed that each of the known Vδ genes can productively rearrange to Jα segments to produce functional Vδ‐Jα‐Cα transcripts. These results argue strongly against the notion that the human Vα repertoires are distinct. They further suggest that the restricted δ repertoire observed in many γ/δ clones results from selection rather than from controlled rearrangements at the T cell receptor α/δ locus.