title: Cloning and sequence determination of a human rheumatoid factor light-chain gene.
abstract: The contribution of germ-line variable regions to autoantibody formation in humans is poorly understood. To study the gene structure of a human autoantibody, chronic lymphatic leukemia (CLL) cells from a patient with an IgM anti-IgG (rheumatoid factor, RF) paraprotein were utilized. The rearranged immunoglobulin gene encoding the kappa light chain for the RF was cloned, and the nucleic acid sequence of its variable region was determined. As demonstrated by Southern blot analysis using a kappa joining-region probe, the CLL cells, stable CLL-WIL2-729-HF2 RF-secreting hybridomas, and the cloned light-chain gene all had an identical restriction fragment containing the rearranged light-chain gene. The CLL RF light chains reacted weakly with an antipeptide antibody against a primary structure-dependent idiotype present on the light chains of the majority of IgM RF paraproteins. The nucleotide and predicted amino acid sequences of the CLL light-chain gene place it in the kappa III variable-region subgroup, and a comparison to known RF paraproteins reveals marked homology to the light-chain amino acid sequence of the IgM RF paraprotein Pom. Both Pom and the CLL light chain appear to identify a second kappa III gene or gene group that is able to encode RF paraprotein light chains.
authors.forename: F R
authors.initials: FR
authors.lastname: Jirik
authors.forename: J
authors.initials: J
authors.lastname: Sorge
authors.forename: S
authors.initials: S
authors.lastname: Fong
authors.forename: J G
authors.initials: JG
authors.lastname: Heitzmann
authors.forename: J G
authors.initials: JG
authors.lastname: Curd
authors.forename: P P
authors.initials: PP
authors.lastname: Chen
authors.forename: R
authors.initials: R
authors.lastname: Goldfien
authors.forename: D A
authors.initials: DA
authors.lastname: Carson
mesh_terms: D000595:Amino Acid Sequence; D001323:Autoantibodies / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D006801:Humans; D006825:Hybridomas; D007130:Immunoglobulin Idiotypes / Q000235:genetics; D007147:Immunoglobulin Light Chains / Q000235:genetics*; D007075:Immunoglobulin M / Q000235:genetics; D007145:Immunoglobulin kappa-Chains / Q000235:genetics; D007945:Leukemia, Lymphoid / Q000235:genetics; D012217:Rheumatoid Factor / Q000235:genetics*
chemical_list: D001323:Autoantibodies; D007130:Immunoglobulin Idiotypes; D007147:Immunoglobulin Light Chains; D007075:Immunoglobulin M; D007145:Immunoglobulin kappa-Chains; D012217:Rheumatoid Factor