Sequence and expression of a novel human T-cell receptor beta-chain variable gene segment subfamily.

We describe the characterization of a novel subfamily of human T-cell receptor beta-chain variable TCRBV gene segments, detected through homology to a mouse Tcrb-V13 gene segment probe. The new human TCRBV gene segment subfamily TCRBV21 contains three members, all of which have been characterized with respect to nucleotide sequence, chromosomal location, and expression in human thymocytes and peripheral T lymphocytes. Our results indicate that one member of the TCRBV21 subfamily is not expressed in either tissue type although its coding region, promoter, recognition, and splice sequences all appear to be functional at the nucleotide level, possibly indicating regulation at the level of transcription.