Open AccessA rheumatoid factor from a normal individual encoded by V H 2 and V k II gene segments
Author(s) -
Stüber Frank,
Lee Soo Kon,
Bridges S. Louis,
Koopman William J.,
Schroeder Harry W.,
Gaskin Felicia,
Fu Shu Man
Publication year - 1992
Publication title -
arthritis & rheumatism
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/art.1780350808
Subject(s) - rheumatoid factor , complementary dna , immunoglobulin light chain , germline , microbiology and biotechnology , complementarity determining region , gene , immunogenetics , biology , antibody , polymerase chain reaction , genetics
Objective. To gain insight into the immunoglobulin variable‐region repertoire of anti‐IgG antibodies (rheumatoid factors [RF]), we characterized the V H and V k gene segments utilized in an IgM‐RF–secreting lymphoblastoid cell line ( SSH 23) isolated from a normal individual. Methods. The cell line SSH 23 was established by Epstein‐Barr virus transformation of peripheral blood non–T mononuclear cells. First‐strand complementary DNA (cDNA) was generated and used for polymerase chain reaction amplification of the heavy and light chain variable domains. The amplified variable domains were sequenced and compared with an extensive database of germline and cDNA V gene segments. Results. The V H sequence was found to be identical to a previously described fetal V H 2 incomplete cDNA and to differ by only 3 nucleotides from a J H proximal germline V H 2 gene segment. To our knowledge, this is the first example of a V H 2 rheumatoid factor. The Vk2–Jk4 light chain contains an uncommon 10–amino acid third complementarity‐determining region (CDR 3). Conclusion. Utilization of preimmune fetal V H gene segments and unusual light chain junctional diversity appear to be features shared by many physiologic and pathologic rheumatoid factors.