title: Human chorionic gonadotropin (HCG) activates monocytes to produce interleukin-8 via a different pathway from luteinizing hormone/HCG receptor system.
abstract: To investigate immune-endocrine interactions between the embryo and the mother early in pregnancy, we examined the effects of human chorionic gonadotropin (HCG) on IL-8 production by peripheral blood mononuclear cells (PBMC). Recombinant HCG promoted IL-8 secretion by PBMC derived from nonpregnant women. The induction of IL-8 mRNA expression was observed after 30 min of HCG stimulation. Adsorption of the HCG with anti-HCG antibodies confirmed the specificity of this effect. The translocation of nuclear factor kappaB into the nucleus and subsequent IL-8 production were observed mainly in monocytes, and IL-8 production was reduced when a proteasome inhibitor was added to inactivate nuclear factor kappaB. Although fluorescein isothiocyanate-labeled HCG was bound to the majority of monocytes, cell surface expression of HCG receptor was hardly detected. IL-8 production by HCG was not affected by inhibitors of protein kinases A and C. In contrast, this stimulation was attenuated by D-mannose, which inhibits binding to C-type lectins. The basal IL-8 production by PBMC from women early in pregnancy was significantly elevated, compared with that from nonpregnant women. This study showed that human monocytes respond to HCG and secrete IL-8 through a pathway different from the HCG receptor system, suggesting that this glycoprotein hormone can react with not only endocrine cells but also immune cells early in pregnancy, probably via primitive systems such as C-type lectins.
authors.affiliation: Department of Gynecology and Obstetrics, Faculty of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Kenzo
authors.initials: K
authors.lastname: Kosaka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujiwara
authors.forename: Keiji
authors.initials: K
authors.lastname: Tatsumi
authors.forename: Shinya
authors.initials: S
authors.lastname: Yoshioka
authors.forename: Yukiyasu
authors.initials: Y
authors.lastname: Sato
authors.forename: Haruto
authors.initials: H
authors.lastname: Egawa
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Higuchi
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nakayama
authors.forename: Masamichi
authors.initials: M
authors.lastname: Ueda
authors.forename: Michiyuki
authors.initials: M
authors.lastname: Maeda
authors.forename: Shingo
authors.initials: S
authors.lastname: Fujii
mesh_terms: D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D006063:Chorionic Gonadotropin / Q000378:metabolism / Q000494:pharmacology*; D003546:Cysteine Endopeptidases; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D005260:Female; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D015870:Gene Expression / Q000187:drug effects; D005865:Gestational Age; D006107:Granulosa Cells / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D007976:Leupeptins / Q000494:pharmacology; D018950:Lipopolysaccharide Receptors / Q000032:analysis; D008358:Mannose / Q000494:pharmacology; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors; D016328:NF-kappa B / Q000378:metabolism; D011247:Pregnancy; D011374:Progesterone / Q000096:biosynthesis; D046988:Proteasome Endopeptidase Complex; D012333:RNA, Messenger / Q000096:biosynthesis; D011974:Receptors, LH / Q000032:analysis; D011994:Recombinant Proteins / Q000378:metabolism / Q000494:pharmacology
chemical_list: D006063:Chorionic Gonadotropin; D015853:Cysteine Proteinase Inhibitors; D005456:Fluorescent Dyes; D016209:Interleukin-8; D007976:Leupeptins; D018950:Lipopolysaccharide Receptors; D009097:Multienzyme Complexes; D016328:NF-kappa B; D012333:RNA, Messenger; D011974:Receptors, LH; D011994:Recombinant Proteins; D011374:Progesterone; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; D016650:Fluorescein-5-isothiocyanate; D008358:Mannose; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde