T cell receptor CDR3 loop length repertoire is determined primarily by features of the V(D)J recombination reaction.
The third complementarity-determining region (CDR) of the TCR alpha and beta chains forms loops that engage amino acid residues of peptides complexed with MHC. This interaction is central to the specific discrimination of antigenic-peptide-MHC complexes by the TCR. The TCRbeta chain CDR3 loop is encoded by the Dbeta gene segment and flanking portions of the Vbeta and Jbeta gene segments. The joining of these gene segments is imprecise, leading to significant variability in the TCRbeta chain CDR3 loop length and amino acid composition. In marked contrast to other pairing antigen-receptor chains, the TCR beta and alpha chain CDR3 loop size distributions are relatively narrow and closely matched. Thus, pairing of TCR alpha and beta chains with relatively similar CDR3 loop sizes may be important for generating a functional repertoire of alpha beta TCR. Here we show that the TCRbeta chain CDR3 loop size distribution is minimally impacted by TCRbeta chain or alpha beta TCR selection during thymocyte development. Rather, this distribution is determined primarily at the level of variable-region gene assembly, and is critically dependent on unique features of the V(D)J recombination reaction that ensure Dbeta gene segment utilization.
Hughes
Maureen M
MM
Department of Pathology and Immunology, Washington University School of Medicine, St. Louis 63110, USA.
Yassai
Maryam
M
Sedy
John R
JR
Wehrly
Tara D
TD
Huang
Ching-Yu
CY
Kanagawa
Osami
O
Gorski
Jack
J
Sleckman
Barry P
BP
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D017637:Clonal Deletion; D022801:Complementarity Determining Regions / Q000737:chemistry / Q000235:genetics*; D004254:DNA Nucleotidyltransferases / Q000378:metabolism*; D015333:Gene Rearrangement, beta-Chain T-Cell Antigen Receptor / Q000235:genetics*; D019673:Genes, T-Cell Receptor alpha; D019674:Genes, T-Cell Receptor beta; D008198:Lymph Nodes / Q000166:cytology; D051379:Mice; D008810:Mice, Inbred C57BL; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics*; D011995:Recombination, Genetic; D013154:Spleen / Q000166:cytology; D016176:T-Lymphocyte Subsets / Q000737:chemistry / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology; D045567:VDJ Recombinases
D022801:Complementarity Determining Regions; D016693:Receptors, Antigen, T-Cell, alpha-beta; D004254:DNA Nucleotidyltransferases; D045567:VDJ Recombinases