Proteolytic processing of the streptococcal IgG endopeptidase IdeS modulates the functional properties of the enzyme and results in reduced immunorecognition.
The important human gram positive bacterial pathogen Streptococcus pyogenes employs various virulence factors to promote inflammation and to facilitate invasive disease progression. In this study we explored the relation of the secreted streptococcal cysteine proteases IdeS and SpeB, and neutrophil (PMN) proteases. We found that SpeB is resistant to proteolytic attack in an inflammatory environment, emphasizing the importance of SpeB for streptococcal pathogenicity, while PMN enzymes and SpeB itself process the IgG degrading endopeptidase IdeS. Processing occurs as NH2-terminal cleavage of IdeS resulting in reduced immunorecognition of the protease by specific antibodies. While the endopeptidase retains IgG cleaving activity, its ability to suppress the generation of reactive oxygen species is abolished. We suggest that the cleavage of NH2-terminal peptides by SpeB and/or neutrophil proteases is a mechanism evolved to prevent early inactivation of this important streptococcal virulence factor, albeit at the cost of impaired functionality.
Department of Molecular Biology, Umeå Centre of Microbial Research, Umeå University, Umeå, Sweden.
Helena
H
Persson
Department of Molecular Biology, Umeå Centre of Microbial Research, Umeå University, Umeå, Sweden.
Jenny Johansson
JJ
Söderberg
Department of Molecular Biology, Umeå Centre of Microbial Research, Umeå University, Umeå, Sweden.
Reine
R
Vindebro
Novo Nordisk A/S, Gentofte, Denmark.
Björn P
BP
Johansson
Department of Molecular Biology, Umeå Centre of Microbial Research, Umeå University, Umeå, Sweden. Electronic address: Ulrich.von-pawel@molbiol.umu.se.
Ulrich
U
von Pawel-Rammingen
D000595:Amino Acid Sequence; D000907:Antibodies, Bacterial / Q000235:genetics / Q000276:immunology*; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D005098:Exotoxins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D015870:Gene Expression; D054884:Host-Pathogen Interactions; D006801:Humans; D007074:Immunoglobulin G / Q000235:genetics; D019272:Leukocyte Elastase / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D008969:Molecular Sequence Data; D009504:Neutrophils / Q000201:enzymology / Q000276:immunology; D059748:Proteolysis; D017382:Reactive Oxygen Species / Q000276:immunology / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D013290:Streptococcal Infections / Q000201:enzymology / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D013297:Streptococcus pyogenes / Q000201:enzymology / Q000235:genetics / Q000276:immunology; D014069:Tonsillitis / Q000201:enzymology / Q000235:genetics / Q000276:immunology* / Q000473:pathology
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D005098:Exotoxins; D007074:Immunoglobulin G; C442815:Mac-1-like protein, Streptococcus; D017382:Reactive Oxygen Species; D011994:Recombinant Proteins; C027951:erythrogenic toxin; D019272:Leukocyte Elastase
Cysteine protease; IdeS; Neutrophil proteases; ROS; S. pyogenes; SpeB