title: Pre-B cell receptor signaling induces immunoglobulin κ locus accessibility by functional redistribution of enhancer-mediated chromatin interactions.
abstract: During B cell development, the precursor B cell receptor (pre-BCR) checkpoint is thought to increase immunoglobulin κ light chain (Igκ) locus accessibility to the V(D)J recombinase. Accordingly, pre-B cells lacking the pre-BCR signaling molecules Btk or Slp65 showed reduced germline V(κ) transcription. To investigate whether pre-BCR signaling modulates V(κ) accessibility through enhancer-mediated Igκ locus topology, we performed chromosome conformation capture and sequencing analyses. These revealed that already in pro-B cells the κ enhancers robustly interact with the ∼3.2 Mb V(κ) region and its flanking sequences. Analyses in wild-type, Btk, and Slp65 single- and double-deficient pre-B cells demonstrated that pre-BCR signaling reduces interactions of both enhancers with Igκ locus flanking sequences and increases interactions of the 3'κ enhancer with V(κ) genes. Remarkably, pre-BCR signaling does not significantly affect interactions between the intronic enhancer and V(κ) genes, which are already robust in pro-B cells. Both enhancers interact most frequently with highly used V(κ) genes, which are often marked by transcription factor E2a. We conclude that the κ enhancers interact with the V(κ) region already in pro-B cells and that pre-BCR signaling induces accessibility through a functional redistribution of long-range chromatin interactions within the V(κ) region, whereby the two enhancers play distinct roles.
authors.affiliation: Department of Cell Biology, Erasmus MC Rotterdam, The Netherlands.
authors.forename: Ralph
authors.initials: R
authors.lastname: Stadhouders
authors.affiliation: Department of Pulmonary Medicine, Erasmus MC Rotterdam, The Netherlands.
authors.forename: Marjolein J W
authors.initials: MJ
authors.lastname: de Bruijn
authors.affiliation: Department of Immunology, Erasmus MC Rotterdam, The Netherlands.
authors.forename: Magdalena B
authors.initials: MB
authors.lastname: Rother
authors.affiliation: Department of Pulmonary Medicine, Erasmus MC Rotterdam, The Netherlands.
authors.forename: Saravanan
authors.initials: S
authors.lastname: Yuvaraj
authors.affiliation: Department of Pulmonary Medicine, Erasmus MC Rotterdam, The Netherlands.
authors.forename: Claudia
authors.initials: C
authors.lastname: Ribeiro de Almeida
authors.affiliation: Department of Cell Biology, Erasmus MC Rotterdam, The Netherlands.
authors.forename: Petros
authors.initials: P
authors.lastname: Kolovos
authors.affiliation: Department of Immunology, Erasmus MC Rotterdam, The Netherlands.
authors.forename: Menno C
authors.initials: MC
authors.lastname: Van Zelm
authors.affiliation: Center for Biomics, Erasmus MC Rotterdam, The Netherlands.
authors.forename: Wilfred
authors.initials: W
authors.lastname: van Ijcken
authors.affiliation: Department of Cell Biology, Erasmus MC Rotterdam, The Netherlands ; The Cancer Genomics Center, Erasmus MC Rotterdam, The Netherlands.
authors.forename: Frank
authors.initials: F
authors.lastname: Grosveld
authors.affiliation: Department of Cell Biology, Erasmus MC Rotterdam, The Netherlands ; The Cancer Genomics Center, Erasmus MC Rotterdam, The Netherlands ; INSERM UMR967 and French Alternative Energies and Atomic Energy Commission (CEA), Fontenay-aux-Roses, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Soler
authors.affiliation: Department of Pulmonary Medicine, Erasmus MC Rotterdam, The Netherlands.
authors.forename: Rudi W
authors.initials: RW
authors.lastname: Hendriks
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002843:Chromatin / Q000235:genetics / Q000378:metabolism*; D042002:Chromatin Assembly and Disassembly; D004742:Enhancer Elements, Genetic; D004843:Epistasis, Genetic; D006657:Histones / Q000378:metabolism; D007145:Immunoglobulin kappa-Chains / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D054448:Precursor Cells, B-Lymphoid / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D011947:Receptors, Antigen, B-Cell / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D059467:Transcriptome; D060152:V(D)J Recombination
chemical_list: D002843:Chromatin; D006657:Histones; D007145:Immunoglobulin kappa-Chains; D011947:Receptors, Antigen, B-Cell