title: The cytoplasmic linker protein CLIP-170 is a human autoantigen.
abstract: The purpose of this study was to identify autoantigens that are recognized by human sera and are associated with a speckled cytoplasmic fluorescent staining pattern on tissue culture cells, and to determine clinical features associated with specific autoantibodies. A serum from a patient with systemic lupus erythematosus was used to identify a 3.7-kb cDNA insert from a HeLa cell expression library. The purified cDNA (VLK2.1) encoded a peptide of 1051 amino acids that shared 98.4% similarity with the carboxyl terminal portion of a previously reported 170 kD protein named cytoplasmic linker protein-170 (CLIP-170). Antibodies affinity purified with the recombinant CLIP-170 protein, the prototype human serum and a monoclonal antibody raised against CLIP-170 exhibited identical speckled staining of the cytoplasm in HEp-2 cells. The human autoantibodies reacted with the purified recombinant protein in a Western immunoblot and immunoprecipitated the in vitro translated recombinant protein. Three additional human sera also immunoprecipitated the recombinant CLIP-170 protein. The clinical diagnoses in these patients were limited scleroderma, glioblastoma and idiopathic pleural effusion. This is the first report that identifies CLIP-170 as a human autoantigen.
authors.affiliation: Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada.
authors.forename: K J
authors.initials: KJ
authors.lastname: Griffith
authors.forename: J P
authors.initials: JP
authors.lastname: Ryan
authors.forename: J-L
authors.initials: JL
authors.lastname: Senécal
authors.forename: M J
authors.initials: MJ
authors.lastname: Fritzler
mesh_terms: D001324:Autoantigens / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D002460:Cell Line; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D005909:Glioblastoma / Q000175:diagnosis / Q000276:immunology; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D009363:Neoplasm Proteins; D010996:Pleural Effusion / Q000175:diagnosis / Q000276:immunology; D011233:Precipitin Tests; D012594:Scleroderma, Localized / Q000175:diagnosis / Q000276:immunology
chemical_list: D001324:Autoantigens; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; C076744:cytoplasmic linker protein 170