Assessing the role of the T cell receptor beta gene enhancer in regulating coding joint formation during V(D)J recombination.
To assess the role of the T cell receptor (TCR) beta gene enhancer (Ebeta) in regulating the processing of VDJ recombinase-generated coding ends, we assayed TCRbeta rearrangement of Ebeta-deleted (DeltaEbeta) thymocytes in which cell death is inhibited via expression of a Bcl-2 transgene. Compared with DeltaEbeta, DeltaEbeta Bcl-2 thymocytes show a small accumulation of TCRbeta standard recombination products, including coding ends, that involves the proximal Dbeta-Jbeta and Vbeta14 loci but not the distal 5' Vbeta genes. These effects are detectable in double negative pro-T cells, predominate in double positive pre-T cells, and correlate with regional changes in chromosomal structure during double negative-to-double positive differentiation. We propose that Ebeta, by driving long range nucleoprotein interactions and the control of locus expression and chromatin structure, indirectly contributes to the stabilization of coding ends within the recombination processing complexes. The results also illustrate Ebeta-dependent and -independent changes in chromosomal structure, suggesting distinct modes of regulation of TCRbeta allelic exclusion depending on the position within the locus.
Mathieu
Noëlle
N
Centre d'Immunologie de Marseille-Luminy, INSERM, CNRS, Université de la Méditerranée, 13288 Marseille, France.
Spicuglia
Salvatore
S
Gorbatch
Sophie
S
Cabaud
Olivier
O
Fernex
Corinne
C
Verthuy
Christophe
C
Hempel
William M
WM
Hueber
Anne-Odile
AO
Ferrier
Pierre
P
D000483:Alleles; D000818:Animals; D002843:Chromatin / Q000378:metabolism; D004254:DNA Nucleotidyltransferases / Q000378:metabolism*; D004260:DNA Repair; D004742:Enhancer Elements, Genetic; D005434:Flow Cytometry; D019674:Genes, T-Cell Receptor beta / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D008957:Models, Genetic; D016133:Polymerase Chain Reaction; D011995:Recombination, Genetic; D013950:Thymus Gland / Q000166:cytology; D045567:VDJ Recombinases
D002843:Chromatin; D004254:DNA Nucleotidyltransferases; D045567:VDJ Recombinases