title: Trophoblast induces monocyte differentiation into CD14+/CD16+ macrophages.
abstract: OBJECTIVE
  During early pregnancy, macrophages and trophoblast come into close contact during placenta development, and regulated cross talk between these cellular compartments is crucial for maintaining a healthy pregnancy. As trophoblast cells constitutively secrete many chemokines and cytokines, we hypothesize that trophoblast-secreted factors can differentiate monocytes into a decidual phenotype. In this study, we describe a unique macrophage phenotype, following monocytes' exposure to trophoblast-soluble factors.
  
  
  METHODS
  Peripheral blood monocytes were treated with or without conditioned media (CM) from first trimester trophoblast cells. Phenotypic changes and phagocytic capacity were determined by flow cytometry. Cytokine and chemokine production was determined by multiplex analysis.
  
  
  RESULTS
  Monocytes exposed to trophoblast factors undergo morphologic changes characterized by a gain in size and complexity and acquire a unique phenotype characterized by gain of CD14 surface expression as well as CD16. The presence of CD14+/CD16+ macrophages was confirmed in normal decidua. These cells secrete higher levels of IL-1b, IL-10, and IP-10 and have increased capacity for phagocytosis.
  
  
  CONCLUSIONS
  We demonstrate that trophoblast-secreted factors can induce monocyte differentiation into a unique macrophage phenotype. These findings suggest that the microenvironment of the placenta can modulate the phenotype of macrophages present at the decidua.
authors.affiliation: Department of Obstetrics Gynecology and Reproductive Science, Yale University School of Medicine, New Haven, CT, USA.
authors.forename: Paulomi B
authors.initials: PB
authors.lastname: Aldo
authors.forename: Karen
authors.initials: K
authors.lastname: Racicot
authors.forename: Vinicius
authors.initials: V
authors.lastname: Craviero
authors.forename: Seth
authors.initials: S
authors.lastname: Guller
authors.forename: Roberto
authors.initials: R
authors.lastname: Romero
authors.forename: Gil
authors.initials: G
authors.lastname: Mor
mesh_terms: D002454:Cell Differentiation; D002460:Cell Line; D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology; D058851:GPI-Linked Proteins / Q000276:immunology; D006801:Humans; D018950:Lipopolysaccharide Receptors / Q000276:immunology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000276:immunology*; D009000:Monocytes / Q000166:cytology* / Q000187:drug effects / Q000276:immunology; D010587:Phagocytosis; D017452:Receptors, IgG / Q000276:immunology; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D014327:Trophoblasts / Q000276:immunology*
chemical_list: D016207:Cytokines; C428200:FCGR3B protein, human; D058851:GPI-Linked Proteins; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D017452:Receptors, IgG; D016212:Transforming Growth Factor beta
keywords: Decidua; inflammation; macropahge; placenta; trophoblast