Human IgG Increases Virulence of Streptococcus pyogenes through Complement Evasion.

ABSTRACT: Streptococcus pyogenes is an exclusively human pathogen that can provoke mild skin and throat infections but can also cause fatal septicemia. This gram-positive bacterium has developed several strategies to evade the human immune system, enabling S. pyogenes to survive in the host. These strategies include recruiting several human plasma proteins, such as the complement inhibitor, C4b-binding protein (C4BP), and human (hu)-IgG through its Fc region to the bacterial surface to evade immune recognition. We identified a novel virulence mechanism whereby IgG-enhanced binding of C4BP to five of 12 tested S. pyogenes strains expressed diverse M proteins that are important surface-expressed virulence factors. Importantly, all strains that bound C4BP in the absence of IgG boun

SUBMITTER: Ermert D 

PROVIDER: S-EPMC6028238 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature