Interleukin-1 in Lipopolysaccharide Induced Chorioamnionitis in the Fetal Sheep

Clare A. Berry, Ilias Nitsos, Noah H. Hillman, J. Jane Pillow, Graeme R. Polglase, Boris W. Kramer, Matthew W. Kemp, John P. Newnham, Alan H. Jobe, Suhas G. Kallapur*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

24 Citations (Web of Science)


We tested the hypothesis that interleukin 1 (IL-1) mediates intra-amniotic lipopolysaccharide (LPS)-induced chorioamnionitis in pretermfetal sheep. Time-mated Merino ewes with singleton fetuses received IL-1 alpha, LPS, or saline (control) by intra-amniotic injection 1 to 2 days before operative delivery at 124 +/- 1 days gestational age (N = 5-9/group; term =d 150 days). Recombinant human IL-1 receptor antagonist (rhIL-1ra) was given into the amniotic fluid 3 hours before intra-amniotic LPS or saline to block IL-1 signaling. Inflammation in the chorioamnion was determined by histology, cytokine messenger RNA (mRNA), protein expression, and by quantitation of activated inflammatory cells. Intra-amniotic IL-1 and LPS both induced chorioamnionitis. However, IL-1 blockade with IL-1ra did not decrease intra-amniotic LPS-induced increases in pro-inflammatory cytokine mRNAs, numbers of inflammatory cells, myeloperoxidase, or monocyte chemotactic protein-1-expressing cells in the chorioamnion. We conclude that IL-1 and LPS both can cause chorioamnionitis, but IL-1 is not an important mediator of LPS-induced chorioamnionitis in fetal sheep.
Original languageEnglish
Pages (from-to)1092-1102
JournalReproductive Sciences
Issue number11
Publication statusPublished - Nov 2011


  • fetal inflammatory response syndrome
  • prematurity
  • innate immunity
  • IL-1 receptor antagonist

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