Activation of the IL-1β/CXCL1/MMP-10 axis in chorioamnionitis induced by inactivated Group B Streptococcus

Placenta. 2016 Nov;47:116-123. doi: 10.1016/j.placenta.2016.09.016. Epub 2016 Sep 27.


Infection or inflammation during pregnancy is known to lead to maternal immune activation triggering a fetal inflammatory response syndrome associated with deleterious effects, such as brain injury and neurodevelopmental disabilities. Group B Streptococcus (GBS) - one of the most common bacterium colonizing pregnant women - can be responsible for chorioamnionitis. Given that interleukin (IL)-1β has a major role in anti-GBS host defense, we hypothesized that IL-1β-driven innate immune response is implicated in GBS-induced chorioamnionitis. Using a rat model of GBS-induced chorioamnionitis, this study showed that inflammatory response to this pathogen was associated with maternal and placental IL-1β hyper expression. Following placental chemokine (C-X-C motif) ligand 1 (CXCL1) production, polymorphonuclear leukocytes (PMN) placental infiltration started at 24 h post-GBS exposure, and MMP-10 was released within these placentas. At 72 h, PMN infiltration extended to membranes and to membranes' arteries. This was associated with IL-1β release within the fetus blood at 72 h. Such a GBS-associated inflammatory cascade might be deleterious for fetal organs. These results pave the way toward targeted placento-protective anti-inflammatory strategies against GBS-induced chorioamnionitis.

Keywords: Chorioamnionitis; Group B Streptococcus; Inflammation; Interleukin-1β; Maternal immune activation; Placenta.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chemokine CXCL1 / metabolism*
  • Chorioamnionitis / metabolism*
  • Chorioamnionitis / microbiology
  • Disease Models, Animal
  • Female
  • Interleukin-1beta / metabolism*
  • Matrix Metalloproteinase 10 / metabolism*
  • Placenta / metabolism*
  • Placenta / microbiology
  • Pregnancy
  • Rats
  • Streptococcal Infections / metabolism*
  • Streptococcus*


  • Chemokine CXCL1
  • Cxcl1 protein, rat
  • Interleukin-1beta
  • Matrix Metalloproteinase 10

Grant support