title: Estrogen and progesterone regulate the IL-6 signal transduction pathway in antibody secreting cells.
abstract: Regulation of the immune response is necessary to allow successful pregnancy. Asymmetric IgG antibodies are involved in fetal maintenance. We have previously demonstrated that estrogen (E2) and progesterone (P4) modulate the synthesis of asymmetric antibodies but the underlying mechanisms remain unclear. Since IL-6 and a progesterone-induced blocking factor (PIBF) were shown to regulate asymmetric antibody synthesis, in this work we analyzed whether E2 and P4 were able to modulate IL-6 signal transduction pathways and the ability of P4 to induce PIBF synthesis, in hybridoma B cells was also evaluated. We found that the IL-6 treatment induced an increase in the expression of gp130 and JAK1 by the hybridoma. E2 and P4 diminished the IL-6-induced gp130 expression in a dose-dependent manner, whereas the expression of JAK1 was not significantly affected. At 10(-6)M concentration, the steroids inhibited the phosphorylation of gp130 and diminished the IL-6-induced STAT3 phosphorylation and translocation to the nucleus. Maximal PIBF expression was observed when the hybridoma was cultured with 10(-10)M P4, compared to the control (p<0.05). Results demonstrate two molecular mechanisms, the modulation of the IL-6R signal transduction pathway and PIBF induction, which could be involved in the immunoregulatory role of sexual steroids during pregnancy.
authors.affiliation: Instituto de Estudios de la Inmunidad Humoral Profesor Ricardo A. Margni (IDEHU), Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad de Buenos Aires, Junín 956, 4to piso (1113), Buenos Aires, Argentina. acanell@ffyb.uba.ar
authors.forename: Andrea
authors.initials: A
authors.lastname: Canellada
authors.forename: Irene
authors.initials: I
authors.lastname: Alvarez
authors.forename: Luciana
authors.initials: L
authors.lastname: Berod
authors.forename: Teresa
authors.initials: T
authors.lastname: Gentile
mesh_terms: D000818:Animals; D000921:Antibody-Producing Cells / Q000166:cytology / Q000276:immunology*; D050822:Cytokine Receptor gp130 / Q000235:genetics / Q000378:metabolism; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D015850:Interleukin-6 / Q000276:immunology*; D053613:Janus Kinase 1 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000235:genetics / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism*; D050796:STAT3 Transcription Factor / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D004967:Estrogens; D015850:Interleukin-6; C491677:Pibf1 protein, mouse; D011257:Pregnancy Proteins; D050796:STAT3 Transcription Factor; C494087:Stat3 protein, mouse; D050822:Cytokine Receptor gp130; D011374:Progesterone; D053613:Janus Kinase 1