title: Estradiol and progesterone strongly inhibit the innate immune response of mononuclear cells in newborns.
abstract: Newborns are particularly susceptible to bacterial infections due to qualitative and quantitative deficiencies of the neonatal innate immune system. However, the mechanisms underlying these deficiencies are poorly understood. Given that fetuses are exposed to high concentrations of estradiol and progesterone during gestation and at time of delivery, we analyzed the effects of these hormones on the response of neonatal innate immune cells to endotoxin, bacterial lipopeptide, and Escherichia coli and group B Streptococcus, the two most common causes of early-onset neonatal sepsis. Here we show that at concentrations present in umbilical cord blood, estradiol and progesterone are as powerful as hydrocortisone for inhibition of cytokine production by cord blood mononuclear cells (CBMCs) and newborn monocytes. Interestingly, CBMCs and newborn monocytes are more sensitive to the effects of estradiol and progesterone than adult peripheral blood mononuclear cells and monocytes. This increased sensitivity is associated with higher expression levels of estrogen and membrane progesterone receptors but is independent of a downregulation of Toll-like receptor 2 (TLR2), TLR4, and myeloid differentiation primary response gene 88 in newborn cells. Estradiol and progesterone mediate their anti-inflammatory activity through inhibition of the NF-κB pathway but not the mitogen-activated protein kinase pathway in CBMCs. Altogether, these results suggest that elevated umbilical cord blood concentrations of estradiol and progesterone acting on mononuclear cells expressing high levels of steroid receptors contribute to impair innate immune responses in newborns. Therefore, intrauterine exposure to estradiol and progesterone may participate in increasing susceptibility to infection during the neonatal period.
authors.affiliation: Service of Neonatology, Department of Pediatrics, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland. Eric.Giannoni@chuv.ch
authors.forename: Eric
authors.initials: E
authors.lastname: Giannoni
authors.forename: Laurence
authors.initials: L
authors.lastname: Guignard
authors.forename: Marlies
authors.initials: M
authors.lastname: Knaup Reymond
authors.forename: Matthieu
authors.initials: M
authors.lastname: Perreau
authors.forename: Matthias
authors.initials: M
authors.lastname: Roth-Kleiner
authors.forename: Thierry
authors.initials: T
authors.lastname: Calandra
authors.forename: Thierry
authors.initials: T
authors.lastname: Roger
mesh_terms: D000328:Adult; D015153:Blotting, Western; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D004731:Endotoxins / Q000276:immunology; D004926:Escherichia coli / Q000276:immunology; D004958:Estradiol / Q000097:blood* / Q000494:pharmacology; D005260:Female; D005312:Fetal Blood / Q000166:cytology; D006801:Humans; D007113:Immunity, Innate; D007231:Infant, Newborn; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D055666:Lipopeptides / Q000187:drug effects / Q000276:immunology; D008297:Male; D008875:Middle Aged; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D053594:Myeloid Differentiation Factor 88 / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011374:Progesterone / Q000097:blood* / Q000494:pharmacology; D011987:Receptors, Steroid / Q000235:genetics / Q000378:metabolism; D013291:Streptococcus / Q000276:immunology; D051195:Toll-Like Receptor 2 / Q000235:genetics / Q000276:immunology; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000276:immunology
chemical_list: D016207:Cytokines; D004731:Endotoxins; D055666:Lipopeptides; C507779:MYD88 protein, human; D053594:Myeloid Differentiation Factor 88; D016328:NF-kappa B; D011987:Receptors, Steroid; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D011374:Progesterone; D004958:Estradiol; D020928:Mitogen-Activated Protein Kinases