Article Text

Download PDFPDF
Antibodies and B cells recognising citrullinated proteins display a broad cross-reactivity towards other post-translational modifications
  1. T Kissel1,
  2. S Reijm1,
  3. LM Slot1,
  4. M Cavallari2,
  5. CM Wortel1,
  6. RD Vergroesen1,
  7. G Stoeken-Rijsbergen1,
  8. JC Kwekkeboom1,
  9. ASB Kampstra1,
  10. EWN Levarht1,
  11. JW Drijfhout3,
  12. H Bang4,
  13. KM Bonger5,
  14. GMC Janssen6,
  15. PA van Veelen6,
  16. TWJ Huizinga1,
  17. HU Scherer1,
  18. M Reth2,
  19. REM Toes1
  1. 1Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands
  2. 2Department of Biology III (Molecular Immunology), Freiburg University, Freiburg, Germany
  3. 3Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, The Netherlands
  4. 4Orgentec Diagnostika, Mainz, Germany
  5. 5Department of Biomolecular Chemistry and Synthetic Organic Chemistry, Radboud University, Nijmegen, The Netherlands
  6. 6Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, The Netherlands
  1. Correspondence to T Kissel, Rheumatology, Leiden University Medical Center, Leiden 2300, Netherlands; T.kissel{at}lumc.nl

Abstract

Objective Autoantibodies against antigens carrying distinct post-translational modifications (PTMs), such as citrulline, homocitrulline or acetyllysine, are hallmarks of rheumatoid arthritis (RA). The relation between these anti-modified protein antibody (AMPA)-classes is poorly understood as is the ability of different PTM-antigens to activate B-cell receptors (BCRs) directed against citrullinated proteins (CP). Insights into the nature of PTMs able to activate such B cells are pivotal to understand the ‘evolution’ of the autoimmune response conceivable underlying the disease. Here, we investigated the cross-reactivity of monoclonal AMPA and the ability of different types of PTM-antigens to activate CP-reactive BCRs.

Methods BCR sequences from B cells isolated using citrullinated or acetylated antigens were used to produce monoclonal antibodies (mAb) followed by a detailed analysis of their cross-reactivity towards PTM-antigens. Ramos B-cell transfectants expressing CP-reactive IgG BCRs were generated and their activation on stimulation with PTM-antigens investigated.

Results Most mAbs were highly cross-reactive towards multiple PTMs, while no reactivity was observed to the unmodified controls. B cells carrying CP-reactive BCRs showed activation on stimulation with various types of PTM-antigens.

Conclusions Our study illustrates that AMPA exhibit a high cross-reactivity towards at least two PTMs indicating that their recognition pattern is not confined to one type of modification. Furthermore, our data show that CP-reactive B cells are not only activated by citrullinated, but also by carbamylated and/or acetylated antigens. These data are vital for the understanding of the breach of B-cell tolerance against PTM-antigens and the possible contribution of these antigens to RA-pathogenesis.

  • rheumatoid arthritis
  • autoantibodies
  • B cells
View Full Text

Statistics from Altmetric.com

Footnotes

  • Handling editor Josef S Smolen

  • TK and SR contributed equally.

  • Contributors All authors were involved in drafting the article or revising it critically for important intellectual content, and all authors approved the final version to be published.

  • Funding This work has been financially supported by ReumaNederland (17-1-402), the IMI funded project RTCure (777357), ZonMw TOP (91214031) and Target-to-B (LSHM18055-SGF). HUS is the recipient of a NWO-ZonMW clinical fellowship (90714509), a NWO-ZonMW VENI grant (91617107), a ZonMW Enabling Technology Hotels grant (435002030) and received support from the Dutch Arthritis Foundation (15-2-402 and 18-1-205). M.Reth is funded by the Excellence Initiative of the German Federal and State Governments (EXC 294) and by the DFG through TRR130-P02 and the RO1 grant (A031503). P.A. van Veelen is funded by an Investment Grant NWO Medium (91116004), which is (partially) financed by ZonMw.

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement All data relevant to the study are included in the article or uploaded as supplementary information.

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.