The extent of the human germline T-cell receptor V beta gene segment repertoire

Abstract

An assessment of the size of the human TCRBV gene segment repertoire based on the identification of TCRBV gene segments in genomic DNA was undertaken. PCR amplification from cloned and uncloned genomic DNA sources, nucleotide sequencing, Southern blot hybridization, and cosmid cloning were used to identify TCRBV gene segments in multiple unrelated individuals. The key advantages to this approach were: 1) TCRBV gene segments which are expressed only at very low levels in cDNA libraries were still detectable, and 2) it was possible to discriminate between alleles at the same locus vs products of different loci. A total of 63 unique TCRBV gene segments were identified and sequenced. Six of these TCRBV gene segments had not been previously described. Thirty-four cosmid clones containing 51 of the 63 identified TCRBV gene segments were isolated and screened for the presence of additional novel TCRBV subfamily members. These results, obtained by a variety of complementary approaches, indicate that the human TCRBV germline repertoire encodes at least 63 TCRBV gene segments of which 52 are functional. The availability of the majority of these TCRBV gene segments on cosmid clones should facilitate further investigation of germline TCRBV gene segment polymorphism and putative disease associations.

Increased proinflammatory cytokine gene expression in the colonic mucosa of coeliac disease patients in the early period after gluten challenge

“…Although the specific mechanism by which gluten challenge leads to the up-regulated expression of proinflammatory cytokines in the rectal mucosa is not known, we note that each of these cytokines is expressed by monocytes/macrophages, and IL-8 and MCP-1 can be expressed by human colon epithelial cells [29,38]. Thus, monocytes/macrophages, epithelial [44]. Lanes 1, 3 and 5 are before, and lanes 2, 4 and 6 are 4 h after gluten challenge.…”

Design and standardization of PCR primers and protocols for detection of clonal immunoglobulin and T-cell receptor gene recombinations in suspect lymphoproliferations: Report of the BIOMED-2 Concerted Action BMH4-CT98-3936

“…Jb region loci are classified into two families according to their genomic localization, not to sequence similarity. 85,86,89 Owing to the large germline-encoded repertoire, the combinatorial diversity of TCRB gene rearrangements is extensive compared to the TCRG and TCRD rearrangements. The primary repertoire of the TCRb molecules is further extended by an addition of an average of 3.6 (Vb-Db junction) and 4.6 (Db-Jb junction) nucleotides and deletion of an average of 3.6 (Vb), 3.8 (5 0 of Db), 3.7 (3 0 of Db), and 4.1 (Jb) nucleotides.…”

Characterization of the T cell receptor repertoire of neonatal T cells by RT-PCR and single strand conformation polymorphism analysis

“…1,2 At present, more than 65 different V␤ genes, a quarter of which are represented by pseudogenes, have been identified. [3][4][5] The V(D)J junctional diversity is further increased by other molecular mechanisms which include imprecise joining of V(D)J recombination, 6 N-region diversification (random addition of nucleotides by terminal deoxy-ribonucleotidyl transferase) 7,8 and insertions of palindromic nucleotides 9 at specific points of the VD, DJ and VJ junctions. As a result of allele exclusion, 10 each T cell clone expresses one and only one specifically rearranged TCR V␤ chain.…”