Identification of HnRNP-A2/B1 as a target antigen of anti-endothelial cell IgA antibody in Behçet's disease.
Behçet's disease (BD) is a chronic, multisystemic vasculitis that theoretically affects all sizes and types of blood vessels. Although pathogenesis remains enigmatic, endothelial cells are believed to be the primary target in this disease. We detected the target protein using western blotting and immunoprecipitation and determined the amino-acid sequence of the peptide by liquid chromatography-matrix assisted laser desorption/ionization-tandem time-of-flight analysis (LC-MALDI-TOF/TOF). Serum reactivity against the recombinant target protein was analyzed by immunoblotting. Serum reactivity against streptococcal 65-kD heat shock protein (hsp-65) and the recombinant target protein was investigated by ELISA. The 36-40-kD protein band that was obtained from immunoprecipitation, which was analyzed by LC-MALDI-TOF/TOF, exhibited the amino-acid sequences of heterogeneous nuclear ribonucleoproteins A2/B1 (hnRNP-A2/B1). Reactivity of serum IgA against human recombinant hnRNP-A2/B1 was detected in 25 of 30 BD patients (83.3%), 4 of 30 systemic lupus erythematosus patients (13.3%), 8 of 30 rheumatoid arthritis patients (26.7%), 9 of 30 Takayasu's arteritis patients (30%), 6 of 30 healthy controls (20%), and none of 30 IgA nephropathy patients. Optical densities obtained from ELISAs against the recombinant human hnRNP-A2/B1 were correlated with those against the recombinant streptococcal hsp-65.JID JOURNAL CLUB ARTICLE: For questions, answers, and open discussion about this article, please go to http://www.nature.com/jid/journalclub.
Department of Dermatology and Cutaneous Biology Research Institute, Yonsei University College of Medicine, Seoul, Korea.
Sung Bin
SB
Cho
Keun Jae
KJ
Ahn
Do Hee
DH
Kim
Zhenlong
Z
Zheng
Suhyun
S
Cho
Shin-Wook
SW
Kang
Ju Hee
JH
Lee
Yong-Beom
YB
Park
Kwang Hoon
KH
Lee
Dongsik
D
Bang
D000328:Adult; D000595:Amino Acid Sequence; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000276:immunology; D001323:Autoantibodies / Q000097:blood / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology; D001528:Behcet Syndrome / Q000097:blood / Q000276:immunology*; D005260:Female; D005922:Glomerulonephritis, IGA / Q000097:blood / Q000276:immunology; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology*; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000276:immunology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D013291:Streptococcus / Q000276:immunology; D013625:Takayasu Arteritis / Q000097:blood / Q000276:immunology
D001323:Autoantibodies; D001324:Autoantigens; D001426:Bacterial Proteins; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D007070:Immunoglobulin A