Identification of kinectin as a novel Behçet's disease autoantigen

Yu Lu¹^,2 , Ping Ye¹^,2, Shun-le Chen², Eng M Tan¹ and Edward KL Chan³

¹Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, USA

²Department of Rheumatology, Shanghai Ren Ji Hospital affiliated to Shanghai Second Medical University, Shanghai, China

³Department of Oral Biology, University of Florida, Gainesville, FL, USA

author email corresponding author email

Arthritis Research & Therapy 2005, 7:R1133-R1139doi:10.1186/ar1798


Published:	27 July 2005

Abstract

There has been some evidence that Behçet's disease (BD) has a significant autoimmune component but the molecular identity of putative autoantigens has not been well characterized. In the initial analysis of the autoantibody profile in 39 Chinese BD patients, autoantibodies to cellular proteins were uncovered in 23% as determined by immunoblotting. We have now identified one of the major autoantibody specificities using expression cloning. Serum from a BD patient was used as a probe to immunoscreen a λZAP expression cDNA library. Candidate autoantigen cDNAs were characterized by direct nucleotide sequencing and their expressed products were examined for reactivity to the entire panel of BD sera using immunoprecipitation. Reactivity was also examined with normal control sera and disease control sera from patients with lupus and Sjögren's syndrome. Six independent candidate clones were isolated from the cDNA library screen and were identified as overlapping partial human kinectin cDNAs. The finding that kinectin was an autoantigen was verified in 9 out of 39 (23%) BD patient sera by immunoprecipitation of the in vitro translation products. Sera from controls showed no reactivity. The significance of kinectin as a participant in autoimmune pathogenesis in BD and the potential use of autoantibody to kinectin in serodiagnostics are discussed.