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

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.