Reina Tsuda1, Tatsuhiko Ozawa1, Eiji Kobayashi1, Hiroshi Hamana1, Hirofumi Taki1, Kazuyuki Tobe1, Eiji Sugiyama1, Masahiro Iwamoto2, Johji Imura1, Hiroyuki Kishi1, Atsushi Muraguchi1. 1. Dana-Farber Cancer Institute, Boston, Massachusetts), Hiroshi Hamana, PhD, Hirofumi Taki, MD, PhD, Kazuyuki Tobe, MD, PhD, Eiji Sugiyama, MD, PhD (current address: Hiroshima University Hospital, Hiroshima, Japan), Johji Imura, MD, PhD, Hiroyuki Kishi, PhD, Atsushi Muraguchi, MD, PhD: University of Toyama Graduate School of Medicine and Pharmaceutical Sciences, Sugitani Campus, Toyama, Japan. 2. Jichi Medical University, Shimotsuke, Tochigi, Japan.
Abstract
OBJECTIVE: To investigate the reactivity of monoclonal anti-citrullinated protein antibody (ACPA) obtained from peripheral blood B cells of rheumatoid arthritis (RA) patients with human autoantigens as well as environmental proteins by determining the essential epitope for the ACPA. METHODS: A human monoclonal ACPA (cyclic citrullinated peptide antibody 1 [CCP-Ab1]) was obtained by screening peripheral blood lymphocytes from 31 patients with RA using a novel monoclonal antibody-secreting cell (ASC) screening system, the immunospot-array assay on a chip. The essential epitope for CCP-Ab1 was determined using epitope mapping. Then, human, microbial, and plant proteins that share the essential epitope identified were searched using BLAST. Finally, representative proteins identified by the search were produced in vitro, and their reactivity with CCP-Ab1 was examined. RESULTS: CCP-Ab1 bound CCP in a citrulline-indispensable manner. In CCP, the 6 amino acid residues required for CCP-Ab1 binding were identified. In the BLAST search, 38 human, 56 viral, 1,383 fungal, 547 bacterial, and 1,072 plant proteins were found to share the essential epitope, and CCP-Ab1 reacted with all of the recombinant citrullinated proteins tested, which included the various environmental factors, such as various plant proteins that are part of the daily diet. CONCLUSION: Our findings demonstrate, for the first time, that a monoclonal ACPA (CCP-Ab1) derived from RA patients cross-reacts not only with various autoantigens but also with numerous plant and microbial proteins. We propose that countless environmental factors, including microbes and diet, may trigger the generation of ACPAs that then cross-react with various citrullinated human autoantigens through molecular mimicry to induce RA.
OBJECTIVE: To investigate the reactivity of monoclonal anti-citrullinated protein antibody (ACPA) obtained from peripheral blood B cells of rheumatoid arthritis (RA) patients with human autoantigens as well as environmental proteins by determining the essential epitope for the ACPA. METHODS: A human monoclonal ACPA (cyclic citrullinated peptide antibody 1 [CCP-Ab1]) was obtained by screening peripheral blood lymphocytes from 31 patients with RA using a novel monoclonal antibody-secreting cell (ASC) screening system, the immunospot-array assay on a chip. The essential epitope for CCP-Ab1 was determined using epitope mapping. Then, human, microbial, and plant proteins that share the essential epitope identified were searched using BLAST. Finally, representative proteins identified by the search were produced in vitro, and their reactivity with CCP-Ab1 was examined. RESULTS: CCP-Ab1 bound CCP in a citrulline-indispensable manner. In CCP, the 6 amino acid residues required for CCP-Ab1 binding were identified. In the BLAST search, 38 human, 56 viral, 1,383 fungal, 547 bacterial, and 1,072 plant proteins were found to share the essential epitope, and CCP-Ab1 reacted with all of the recombinant citrullinated proteins tested, which included the various environmental factors, such as various plant proteins that are part of the daily diet. CONCLUSION: Our findings demonstrate, for the first time, that a monoclonal ACPA (CCP-Ab1) derived from RApatients cross-reacts not only with various autoantigens but also with numerous plant and microbial proteins. We propose that countless environmental factors, including microbes and diet, may trigger the generation of ACPAs that then cross-react with various citrullinated human autoantigens through molecular mimicry to induce RA.
Authors: Jing Shi; Erika Darrah; Gary P Sims; Tomas Mustelin; Kevon Sampson; Maximilian F Konig; Clifton O Bingham; Antony Rosen; Felipe Andrade Journal: Ann Rheum Dis Date: 2017-10-25 Impact factor: 19.103
Authors: Hans Ulrich Scherer; Tom W J Huizinga; Gerhard Krönke; Georg Schett; Rene E M Toes Journal: Nat Rev Rheumatol Date: 2018-02-08 Impact factor: 20.543
Authors: Johanna Steen; Björn Forsström; Peter Sahlström; Victoria Odowd; Lena Israelsson; Akilan Krishnamurthy; Sara Badreh; Linda Mathsson Alm; Joanne Compson; Daniel Ramsköld; Welcome Ndlovu; Stephen Rapecki; Monika Hansson; Philip J Titcombe; Holger Bang; Daniel L Mueller; Anca I Catrina; Caroline Grönwall; Karl Skriner; Peter Nilsson; Daniel Lightwood; Lars Klareskog; Vivianne Malmström Journal: Arthritis Rheumatol Date: 2019-02 Impact factor: 10.995
Authors: Katy A Lloyd; Gustaf Wigerblad; Peter Sahlström; Manasa G Garimella; Karine Chemin; Johanna Steen; Philip J Titcombe; Bianka Marklein; Diana Zhou; Ragnhild Stålesen; Elena Ossipova; Christina Lundqvist; Olov Ekwall; Johan Rönnelid; Daniel L Mueller; Mikael C I Karlsson; Mariana J Kaplan; Karl Skriner; Lars Klareskog; Fredrik Wermeling; Vivianne Malmström; Caroline Grönwall Journal: Front Immunol Date: 2019-01-04 Impact factor: 7.561