title: Germline deletion of Igh 3' regulatory region elements hs 5, 6, 7 (hs5-7) affects B cell-specific regulation, rearrangement, and insulation of the Igh locus.
abstract: Regulatory elements located within an ∼28-kb region 3' of the Igh gene cluster (3' regulatory region) are required for class switch recombination and for high levels of IgH expression in plasma cells. We previously defined novel DNase I hypersensitive sites (hs) 5, 6, 7 immediately downstream of this region. The hs 5-7 region (hs5-7) contains a high density of binding sites for CCCTC-binding factor (CTCF), a zinc finger protein associated with mammalian insulator activity, and is an anchor for interactions with CTCF sites flanking the D(H) region. To test the function of hs5-7, we generated mice with an 8-kb deletion encompassing all three hs elements. B cells from hs5-7 knockout (KO) (hs5-7KO) mice showed a modest increase in expression of the nearest downstream gene. In addition, Igh alleles in hs5-7KO mice were in a less contracted configuration compared with wild-type Igh alleles and showed a 2-fold increase in the usage of proximal V(H)7183 gene families. Hs5-7KO mice were essentially indistinguishable from wild-type mice in B cell development, allelic regulation, class switch recombination, and chromosomal looping. We conclude that hs5-7, a high-density CTCF-binding region at the 3' end of the Igh locus, impacts usage of V(H) regions as far as 500 kb away.
authors.affiliation: Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
authors.forename: Sabrina A
authors.initials: SA
authors.lastname: Volpi
authors.forename: Jiyoti
authors.initials: J
authors.lastname: Verma-Gaur
authors.forename: Rabih
authors.initials: R
authors.lastname: Hassan
authors.forename: Zhongliang
authors.initials: Z
authors.lastname: Ju
authors.forename: Sergio
authors.initials: S
authors.lastname: Roa
authors.forename: Sanjukta
authors.initials: S
authors.lastname: Chatterjee
authors.forename: Uwe
authors.initials: U
authors.lastname: Werling
authors.forename: Harry
authors.initials: H
authors.lastname: Hou
authors.forename: Britta
authors.initials: B
authors.lastname: Will
authors.forename: Ulrich
authors.initials: U
authors.lastname: Steidl
authors.forename: Matthew
authors.initials: M
authors.lastname: Scharff
authors.forename: Winfried
authors.initials: W
authors.lastname: Edelman
authors.forename: Ann J
authors.initials: AJ
authors.lastname: Feeney
authors.forename: Barbara K
authors.initials: BK
authors.lastname: Birshtein
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D000076246:CCCTC-Binding Factor; D005434:Flow Cytometry; D050438:Genes, Immunoglobulin Heavy Chain / Q000235:genetics* / Q000276:immunology; D018095:Germ-Line Mutation; D017578:Immunoglobulin Class Switching / Q000235:genetics / Q000276:immunology; D017404:In Situ Hybridization, Fluorescence; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D016133:Polymerase Chain Reaction; D012045:Regulatory Sequences, Nucleic Acid / Q000276:immunology*; D012097:Repressor Proteins / Q000235:genetics / Q000276:immunology
chemical_list: D000076246:CCCTC-Binding Factor; C000619698:Ctcf protein, mouse; D012097:Repressor Proteins