Placental macrophages are impaired in chorioamnionitis, an infectious pathology of the placenta

J Immunol. 2013 Dec 1;191(11):5501-14. doi: 10.4049/jimmunol.1300988. Epub 2013 Oct 25.


Pregnancy is dependent on maternal-fetal tolerance that may be compromised because of infections or inflammation of the placenta. In this study, we examined whether the context of placental immune tolerance affected the functions of resident macrophages and if their functions were altered during chorioamnionitis, an infectious pathology of the placenta. Macrophages from at-term placentas expressed CD14, exhibited macrophage microbicidal functions, but were less inflammatory than monocyte-derived macrophages. Moreover, placental macrophages spontaneously matured into multinucleated giant cells (MGCs), a property not exhibited by monocyte-derived macrophages, and we detected MGCs of myeloid origin in placental tissue. Compared with placental macrophages, MGCs exhibited a specific phenotype and gene expression signature, consisting of increased cytoskeleton-associated gene expression along with depressed expression of inflammatory response genes. Furthermore, placental macrophages from patients with chorioamnionitis were unable to form MGCs, but this defect was partially corrected by incubating these placental macrophages with control trophoblast supernatants. MGCs formation likely serves to regulate their inflammatory and cytocidal activities in a context that imposes semiallograft acceptance and defense against pathogens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Animals
  • Cell Differentiation / drug effects
  • Cells, Cultured
  • Chorioamnionitis / etiology
  • Chorioamnionitis / immunology*
  • Culture Media, Conditioned / pharmacology
  • Cytoskeleton / genetics
  • Female
  • Gene Expression Regulation / immunology
  • Giant Cells / immunology
  • Humans
  • Lipopolysaccharide Receptors / metabolism
  • Macrophages / drug effects
  • Macrophages / immunology*
  • Placenta / immunology*
  • Placenta / pathology
  • Pregnancy
  • Pregnancy Complications, Infectious / immunology*
  • Streptococcal Infections / complications
  • Streptococcal Infections / immunology*
  • Streptococcus / immunology*
  • Transplantation Tolerance
  • Young Adult


  • Culture Media, Conditioned
  • Lipopolysaccharide Receptors