title: Identification of three new bovine T-cell receptor delta variable gene subgroups expressed by peripheral blood T cells.
abstract: To understand the biology of gammadelta T cells in ruminants, it is necessary to have a comprehensive picture of gammadelta T-cell receptor gene diversity and expression. In this study, three new subgroups of bovine T-cell receptor delta (TRD) variable genes were identified by RT-PCR and sequencing and homology with TRDV genes from other mammals determined. Previously unidentified TRDV subgroup genes described in this study include the bovine homologues of ovine TRDV2, TRDV3, and TRDV4 which were named accordingly. TRDV2 subgroup has two genes (TRDV2-1 and TRDV2-2) while we found the previously identified TRDV1 has at least eight genes corresponding to separate genomic sequences. Nucleotide and amino acid sequences for particular gene subgroups between cattle and sheep were more than 87% identical but identities among TRDV subgroups within a species were much less, with bovine TRDV4 having <45% identity to the other three bovine TRDV gene subgroups. Analysis of circulating bovine gammadelta T cells revealed that genes from all four TRDV subgroups were expressed in combination with TRDJ1, TRDJ3, and TRDC, although TRDV4 was the least represented, and all displayed a variety of CDR3 junctional lengths. Finally, some genes within the TRDV1, TRDV2, and TRDV3 subgroups recombined with TRAV incorporating TRAJs, suggesting dual use.
authors.affiliation: Department of Veterinary and Animal Sciences, Paige Laboratory, University of Massachusetts, Amherst, MA 01003, USA.
authors.forename: Carolyn T A
authors.initials: CT
authors.lastname: Herzig
authors.forename: Seth L
authors.initials: SL
authors.lastname: Blumerman
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Baldwin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle / Q000235:genetics* / Q000276:immunology*; D002874:Chromosome Mapping; D022801:Complementarity Determining Regions; D004247:DNA / Q000235:genetics; D015870:Gene Expression; D019676:Genes, T-Cell Receptor delta; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D012756:Sheep; D013045:Species Specificity; D016176:T-Lymphocyte Subsets / Q000276:immunology
chemical_list: D022801:Complementarity Determining Regions; D004247:DNA