title: Contribution of Vh gene replacement to the primary B cell repertoire.
abstract: V(H) replacement has been proposed as one way to modify unwanted antibody specificities, but analysis of this mechanism has been limited without a dynamic cellular model. We describe a human cell line that spontaneously undergoes serial V(H) gene replacement mediated by cryptic recombination signal sequences (cRSS) located near the 3' end of V(H) genes. Recombination-activating gene products, RAG-1 and RAG-2, bind and cleave the cRSS to generate DNA deletion circles during the V(H) replacement process. A V(H) replacement contribution to normal repertoire development is revealed by the identification of V(H) replacement "footprints" in IgH sequences and double-stranded DNA breaks at V(H) cRSS sites in immature B cells. Surprisingly, the residual 3' sequences of replaced V(H) genes contribute charged amino acids to the CDR3 region, a hallmark of autoreactive antibodies.
authors.affiliation: Division of Developmental and Clinical Immunology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
authors.forename: Zhixin
authors.initials: Z
authors.lastname: Zhang
authors.forename: Michael
authors.initials: M
authors.lastname: Zemlin
authors.forename: Yui-Hsi
authors.initials: YH
authors.lastname: Wang
authors.forename: Delicia
authors.initials: D
authors.lastname: Munfus
authors.forename: Leslie E
authors.initials: LE
authors.lastname: Huye
authors.forename: Harry W
authors.initials: HW
authors.lastname: Findley
authors.forename: S Louis
authors.initials: SL
authors.lastname: Bridges
authors.forename: David B
authors.initials: DB
authors.lastname: Roth
authors.forename: Peter D
authors.initials: PD
authors.lastname: Burrows
authors.forename: Max D
authors.initials: MD
authors.lastname: Cooper
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology*; D001483:Base Sequence; D002478:Cells, Cultured; D022801:Complementarity Determining Regions; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000502:physiology; D005803:Genes, Immunoglobulin; D018398:Homeodomain Proteins / Q000502:physiology; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D016133:Polymerase Chain Reaction; D011995:Recombination, Genetic
chemical_list: D022801:Complementarity Determining Regions; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D007143:Immunoglobulin Heavy Chains; D007135:Immunoglobulin Variable Region; D009687:Nuclear Proteins; C499311:RAG2 protein, human; C064655:V(D)J recombination activating protein 2; C064658:RAG-1 protein