Human T cells expressing an invariant Vα24-JαQ TCRα are CD4- and heterogeneous with respect to TCRβ expression

A population of mature CD4-CD8-double-negative T cells that expresses an invariant Vα24-JαQ TCR has been identified in humans; the majority of these cells appear to express Vβ11. A closely related invariant TCRα chain is also expressed by a population of NK1+ murine T cells, but these cells may be either CD4+ or double negative. In this report, multiple CD4+ or double- negative Vα24+Vβ11+ T-cell clones were isolated, and only the double- negative clones were found to express the invariant TCRα chain. Studies of TCRβ chains expressed by these cells demonstrate that a subset in some donors use Vβ genes other than Vβ11. Characterization of Vβ11 TCRs in one donor by CDR3-length analysis was also carried our. The results indicate that multiple Vβ11 TCRs of differing CDR3 lengths may associate with the invariant TCRα chain.