title: Diversity and structure of human T-cell receptor beta-chain variable region genes.
abstract: The nucleotide sequences of 27 T-cell receptor beta cDNA clones isolated from a human peripheral lymphocyte library were determined and compared to five additional published sequences. These cDNA clones represent 22 distinct T-cell receptor beta-chain variable region (V beta) gene segment sequences, which fall into 15 different V beta gene subfamilies, each containing six or fewer members. From this analysis, we estimate that the repertoire of expressed human V beta genes is less than 59, apparently much smaller than the immunoglobulin heavy chain and light chain variable region (VH and VL) repertoires. Variability plots comparing these human V beta regions with each other and with published mouse V beta regions provide evidence for only four hypervariable regions homologous to those seen in comparisons of immunoglobulin V regions. Somatic hypermutation appears to be used infrequently, if at all, in these V beta genes.
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D005796:Genes; D006801:Humans; D009154:Mutation; D011110:Polymorphism, Genetic; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D013601:T-Lymphocytes / Q000502:physiology*
chemical_list: D011948:Receptors, Antigen, T-Cell; D004247:DNA