title: Binding of pregnancy-specific glycoprotein 17 to CD9 on macrophages induces secretion of IL-10, IL-6, PGE2, and TGF-beta1.
abstract: Pregnancy-specific glycoproteins (PSGs) are a family of secreted proteins produced by the placenta, which are believed to have a critical role in pregnancy success. Treatment of monocytes with three members of the human PSGs induces interleukin (IL)-10, IL-6, and transforming growth factor-beta(1) (TGF-beta(1)) secretion. To determine whether human and murine PSGs have similar functions and use the same receptor, we treated wild-type and CD9-deficient macrophages with murine PSG17N and human PSG1 and -11. Our data show that murine PSG17N induced secretion of IL-10, IL-6, prostaglandin E(2), and TGF-beta(1) and that CD9 expression is required for the observed induction of cytokines. Therefore, the ability of PSG17 to induce anti-inflammatory cytokines parallels that of members of the human PSG family, albeit human and murine PSGs use different receptors, as CD9-deficient and wild-type macrophages responded equally to human PSGs. We then proceeded to examine the signaling mechanisms responsible for the CD9-mediated response to PSG17. Inhibition of cyclooxygenase 2 significantly reduced the PSG17N-mediated increase in IL-10 and IL-6. Further characterization of the response to PSG17 indicated that cyclic adenosine monophosphate-dependent protein kinase A (PKA) is involved in the up-regulation of IL-10 and IL-6, and it is not required for the induction of TGF-beta(1). Conversely, treatment of macrophages with a PKC inhibitor reduced the PSG17-mediated induction of TGF-beta(1), IL-6, and IL-10 significantly. The induction of anti-inflammatory cytokines by various PSGs supports the hypothesis that these glycoproteins have an essential role in the regulation of the maternal immune response in species with hemochorial placentation.
authors.affiliation: Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
authors.forename: Cam T
authors.initials: CT
authors.lastname: Ha
authors.forename: Roseann
authors.initials: R
authors.lastname: Waterhouse
authors.forename: Jennifer
authors.initials: J
authors.lastname: Wessells
authors.forename: Julie A
authors.initials: JA
authors.lastname: Wu
authors.forename: Gabriela S
authors.initials: GS
authors.lastname: Dveksler
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D051546:Cyclooxygenase 2; D015232:Dinoprostone / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins; D016753:Interleukin-10 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008264:Macrophages / Q000187:drug effects / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008565:Membrane Proteins; D051379:Mice; D011257:Pregnancy Proteins / Q000378:metabolism* / Q000494:pharmacology; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D011493:Protein Kinase C / Q000502:physiology; D060245:Tetraspanin 29; D016212:Transforming Growth Factor beta / Q000378:metabolism; D053773:Transforming Growth Factor beta1
chemical_list: D015703:Antigens, CD; C554869:CD9 protein, human; C554870:Cd9 protein, mouse; D006023:Glycoproteins; D018836:Inflammation Mediators; D036341:Intercellular Signaling Peptides and Proteins; D015850:Interleukin-6; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D011257:Pregnancy Proteins; C508960:TGFB1 protein, human; D060245:Tetraspanin 29; C508961:Tgfb1 protein, mouse; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; C502399:pregnancy-specific glycoprotein 17, mouse; D016753:Interleukin-10; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D011493:Protein Kinase C; D015232:Dinoprostone