GBS hyaluronidase mediates immune suppression in a TLR2/4- and IL-10-dependent manner during pregnancy-associated infection

mBio. 2023 Oct 31;14(5):e0204923. doi: 10.1128/mbio.02049-23. Epub 2023 Sep 25.

Abstract

Bacteria such as GBS can cause infections during pregnancy leading to preterm births, stillbirths, and neonatal infections. The interaction between host and bacterial factors during infections in the placenta is not fully understood. GBS secretes a hyaluronidase enzyme that is thought to digest host hyaluronan into immunosuppressive disaccharides that dampen TLR2/4 signaling, leading to increased bacterial dissemination and adverse outcomes. In this study, we show that GBS HylB mediates immune suppression and promotes bacterial infection during pregnancy that requires TLR2, TLR4, and IL-10. Understanding the interaction between host and bacterial factors can inform future therapeutic strategies to mitigate GBS infections.

Keywords: HylB; IL-10; Streptococcus agalactiaee; hyaluronidase; immune suppression; pregnancy.

MeSH terms

  • Female
  • Humans
  • Hyaluronoglucosaminidase / genetics
  • Infant, Newborn
  • Interleukin-10 / genetics
  • Pregnancy
  • Pregnancy Complications, Infectious* / microbiology
  • Streptococcal Infections* / microbiology
  • Streptococcus agalactiae
  • Toll-Like Receptor 2

Substances

  • Hyaluronoglucosaminidase
  • Toll-Like Receptor 2
  • Interleukin-10
  • TLR2 protein, human