Deiminated Epstein-Barr virus nuclear antigen 1 is a target of anti-citrullinated protein antibodies in rheumatoid arthritis

Arthritis Rheum. 2006 Mar;54(3):733-41. doi: 10.1002/art.21629.

Abstract

Objective: To test the hypothesis that deimination of viral sequences containing Arg-Gly repeats could generate epitopes recognized by anti-citrullinated protein antibodies (ACPAs) that are present in rheumatoid arthritis (RA) sera.

Methods: Multiple antigen peptides derived from Epstein-Barr virus (EBV)-encoded Epstein-Barr nuclear antigen 1 (EBNA-1) were synthesized, substituting the arginines with citrulline, and were used to screen RA sera. Anti-cyclic citrullinated peptide antibodies were purified by affinity chromatography and tested on a panel of in vitro deiminated proteins. Their ability to bind in vivo deiminated proteins was evaluated by immunoprecipitation, using EBV-infected cell lines.

Results: Antibodies specific for a peptide corresponding to the EBNA-1(35-58) sequence containing citrulline in place of arginine (viral citrullinated peptide [VCP]) were detected in 50% of RA sera and in <5% of normal and disease control sera. In addition, affinity-purified anti-VCP antibodies from RA sera reacted with filaggrin-derived citrullinated peptides, with deiminated fibrinogen, and with deiminated recombinant EBNA-1. Moreover, anti-VCP antibodies immunoprecipitated, from the lysate of calcium ionophore-stimulated lymphoblastoid cell lines, an 80-kd band that was reactive with a monoclonal anti-EBNA-1 antibody and with anti-modified citrulline antibodies.

Conclusion: These data indicate that ACPAs react with a viral deiminated protein and suggest that EBV infection may play a role in the induction of these RA-specific antibodies.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Amino Acid Sequence
  • Antibodies, Viral / immunology*
  • Arthritis, Rheumatoid / immunology*
  • Chromatography, Affinity
  • Citrulline / analysis
  • Epstein-Barr Virus Infections / immunology
  • Epstein-Barr Virus Nuclear Antigens / chemistry*
  • Epstein-Barr Virus Nuclear Antigens / immunology*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Nucleoproteins / immunology

Substances

  • Antibodies, Viral
  • Epstein-Barr Virus Nuclear Antigens
  • Nucleoproteins
  • peptide 31D
  • Citrulline