Frontiers in Immunology (Jul 2018)

Streptococcal Endo-β-N-Acetylglucosaminidase Suppresses Antibody-Mediated Inflammation In Vivo

  • Kutty Selva Nandakumar,
  • Kutty Selva Nandakumar,
  • Mattias Collin,
  • Kaisa E. Happonen,
  • Kaisa E. Happonen,
  • Susanna L. Lundström,
  • Allyson M. Croxford,
  • Bingze Xu,
  • Roman A. Zubarev,
  • Merrill J. Rowley,
  • Anna M. Blom,
  • Christian Kjellman,
  • Rikard Holmdahl,
  • Rikard Holmdahl

DOI
https://doi.org/10.3389/fimmu.2018.01623
Journal volume & issue
Vol. 9

Abstract

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Endo-β-N-acetylglucosaminidase (EndoS) is a family 18 glycosyl hydrolase secreted by Streptococcus pyogenes. Recombinant EndoS hydrolyzes the β-1,4-di-N-acetylchitobiose core of the N-linked complex type glycan on the asparagine 297 of the γ-chains of IgG. Here, we report that EndoS and IgG hydrolyzed by EndoS induced suppression of local immune complex (IC)-mediated arthritis. A small amount (1 µg given i.v. to a mouse) of EndoS was sufficient to inhibit IgG-mediated arthritis in mice. The presence of EndoS disturbed larger IC lattice formation both in vitro and in vivo, as visualized with anti-C3b staining. Neither complement binding in vitro nor antigen-antibody binding per se were affected. Thus, EndoS could potentially be used for treating patients with IC-mediated pathology.

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