title: In vitro eradication of citrullinated protein specific B-lymphocytes of rheumatoid arthritis patients by targeted bifunctional nanoparticles.
abstract: BACKGROUND
  Autoreactive B cells are crucial players in the pathogenesis of rheumatoid arthritis (RA). Autoantibodies specific for citrullinated proteins (ACPA), present in the serum of approximately 60-70 % of patients, have a pathogenic role in the disease. B cell depleting therapies may result in a transient immunosuppression, increasing the risk of infections. Our aim was to develop a new therapeutic approach to selectively deplete the ACPA producing autoreactive B cells.
  
  
  METHODS
  To target B cells synthetic citrullinated peptide derived from the β chain of fibrin, β60-74Cit 60,72,74 (β60-74Cit), the predominant epitope recognized by ACPA was used. Complement dependent cytotoxicity (CDC) was induced by a modified peptide derived from gp120 of HIV-1. To trigger CDC both the targeting peptide and the complement activating peptide were covalently coupled in multiple copies to the surface of poly (DL-lactic-co-glycolic acid) nanoparticles (NPs). Ex vivo antibody synthesis was examined by ELISA and ELISpot. CDC was tested after dead cell staining by flow cytometry.
  
  
  RESULTS
  The β60-74Cit peptide was selectively recognized by a small subset of B cells from RA patients having high level of peptide specific serum antibody, suggesting that the peptide can target diseased B cells. The modified gp120 peptide covalently coupled to NPs induced the formation of the complement membrane attack complex, C5b-9 in human serum. We show here for the first time that bifunctional NPs coupled to multiple copies of both the targeting peptide and the complement activating effector peptide on their surface significantly reduce β60-74Cit peptide specific ex vivo ACPA production, by inducing complement dependent lysis of the citrullinated peptide specific B cells of seropositive RA patients.
  
  
  CONCLUSIONS
  Bifunctional NPs covalently coupled to autoantigen epitope peptide and to a lytic peptide activating complement may specifically target and deplete the peptide specific autoreactive B-cells.
authors.affiliation: Department of Immunology, Eötvös Loránd University, Pázmány Péter sétány 1/c, Budapest, 1117, Hungary. pozsgayj@yahoo.com.|MTA-ELTE Research Group of Peptide Chemistry, Hungarian Academy of Sciences, Eötvös Loránd University, Budapest, 1117, Hungary. pozsgayj@yahoo.com.
authors.forename: Judit
authors.initials: J
authors.lastname: Pozsgay
authors.affiliation: MTA-ELTE Research Group of Peptide Chemistry, Hungarian Academy of Sciences, Eötvös Loránd University, Budapest, 1117, Hungary. babosfruzsi@gmail.com.
authors.forename: Fruzsina
authors.initials: F
authors.lastname: Babos
authors.affiliation: MTA-ELTE Research Group of Peptide Chemistry, Hungarian Academy of Sciences, Eötvös Loránd University, Budapest, 1117, Hungary. uray@elte.hu.
authors.forename: Katalin
authors.initials: K
authors.lastname: Uray
authors.affiliation: Department of Immunology, Eötvös Loránd University, Pázmány Péter sétány 1/c, Budapest, 1117, Hungary. magyar@elte.hu.|MTA-ELTE Research Group of Peptide Chemistry, Hungarian Academy of Sciences, Eötvös Loránd University, Budapest, 1117, Hungary. magyar@elte.hu.
authors.forename: Anna
authors.initials: A
authors.lastname: Magyar
authors.affiliation: Laboratory of Interfaces and Nanostructures, Institute of Chemistry, Eötvös Loránd University, Budapest, 1117, Hungary. gyulaigor@gmail.com.
authors.forename: Gergő
authors.initials: G
authors.lastname: Gyulai
authors.affiliation: Laboratory of Interfaces and Nanostructures, Institute of Chemistry, Eötvös Loránd University, Budapest, 1117, Hungary. kisseva@chem.elte.hu.
authors.forename: Éva
authors.initials: É
authors.lastname: Kiss
authors.affiliation: Department of Rheumatology, Polyclinic of the Hospitaller Brothers of St. John of God, Budapest, 1023, Hungary. gyorgyngy@gmail.com.
authors.forename: György
authors.initials: G
authors.lastname: Nagy
authors.affiliation: Department of Rheumatology, Polyclinic of the Hospitaller Brothers of St. John of God, Budapest, 1023, Hungary. rojkovich.b@irgalmas.hu.
authors.forename: Bernadette
authors.initials: B
authors.lastname: Rojkovich
authors.affiliation: MTA-ELTE Research Group of Peptide Chemistry, Hungarian Academy of Sciences, Eötvös Loránd University, Budapest, 1117, Hungary. fhudecz@elte.hu.|Department of Organic Chemistry, Eötvös Loránd University, Budapest, 1117, Hungary. fhudecz@elte.hu.
authors.forename: Ferenc
authors.initials: F
authors.lastname: Hudecz
authors.affiliation: Department of Immunology, Eötvös Loránd University, Pázmány Péter sétány 1/c, Budapest, 1117, Hungary. sarmayg@elte.hu.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Sármay
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000188:drug therapy / Q000378:metabolism*; D001323:Autoantibodies / Q000378:metabolism; D001402:B-Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D002956:Citrulline / Q000378:metabolism*; D003430:Cross-Sectional Studies; D016503:Drug Delivery Systems / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053758:Nanoparticles / Q000008:administration & dosage* / Q000378:metabolism*; D010865:Pilot Projects
chemical_list: D001323:Autoantibodies; D002956:Citrulline