title: Analysis of the genes encoding the variable regions of human IgG rheumatoid factor.
abstract: OBJECTIVE
  To better understand the immunoglobulin variable (V) region repertoire of rheumatoid factors (RF).
  
  
  METHODS
  We characterized the heavy (H) and light (L) chain gene segments utilized in a monospecific IgG RF secreting hybridoma (AEE111F) which were derived from a patient with rheumatoid arthritis (RA). The hybridoma was established by fusion of a mouse myeloma cell line with bone marrow derived mononuclear cells from a patient with RA. First strand complementary DNA (cDNA) was generated and used for a polymerase chain reaction amplification of the H and L chain V domains. The amplified V domains were sequenced and compared with an extensive database of germline and cDNA V gene segments.
  
  
  RESULTS
  The VH sequence was found to be 96% homologous to a previously described fetal VH3 cDNA (60P2). The VL sequence was also highly homologous to the previously described V lambda II gene (96%) derived from a patient with systemic lupus erythematosus which correlated with an 8.12 idiotype (Id), and to an antibacterial antibody against the Haemophilus influenzae type b capsular polysaccharide (94.7%).
  
  
  CONCLUSIONS
  The overlap among this RF VL gene and the 2 reported V lambda sequences of antibodies that expressed anti-DNA related Id and an environmental pathogen specificity suggests that a part of the IgG RF isolated from patients with RA may thus be derived from the physiological natural antibody repertoire during an abnormal immune response and then develop high affinity, monospecific RF by the selection of an antigen driven mechanism.
authors.affiliation: Department of Clinical Immunology, Kyushu University, Fukuoka, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Ezaki
authors.forename: M
authors.initials: M
authors.lastname: Shingu
authors.forename: M
authors.initials: M
authors.lastname: Hashimoto
authors.forename: T
authors.initials: T
authors.lastname: Isayama
authors.forename: J
authors.initials: J
authors.lastname: Tohmatsu
authors.forename: H
authors.initials: H
authors.lastname: Kanda
authors.forename: M
authors.initials: M
authors.lastname: Nobunaga
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
mesh_terms: D000595:Amino Acid Sequence; D001172:Arthritis, Rheumatoid / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D002460:Cell Line; D004797:Enzyme-Linked Immunosorbent Assay; D015870:Gene Expression; D005803:Genes, Immunoglobulin / Q000235:genetics*; D006801:Humans; D007074:Immunoglobulin G / Q000235:genetics*; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007147:Immunoglobulin Light Chains / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012217:Rheumatoid Factor / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
chemical_list: D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; D012217:Rheumatoid Factor