Nod1, but not the ASC inflammasome, contributes to induction of IL-1β secretion in human trophoblasts after sensing of Chlamydia trachomatis

Mucosal Immunol. 2013 Mar;6(2):235-43. doi: 10.1038/mi.2012.63. Epub 2012 Jul 4.


Chlamydia trachomatis (Ct) is an obligate intracellular bacterial pathogen. Previously, we showed that infection of human trophoblast cells by Ct triggers the secretion of the pro-inflammatory cytokine, interleukin (IL)-1β. The aim of this study was to understand the innate immune pathways involved in trophoblast production of IL-1β after Ct infection. The approach we took was to inhibit the expression or function of the key Toll-like receptors (TLRs), Nod-like receptors, and inflammasome components that have been associated with chlamydia infection. In this study, we report that Ct-induced trophoblast IL-1β secretion is associated with the transcription of IL-1β mRNA, the translation and processing of pro-IL-1β, and the activation of caspase-1. In addition, we demonstrate that Ct-induced IL-1β production and secretion by the trophoblast is independent of TLR2, TLR4, MyD88, and the Nalp3/ASC inflammasome. Instead we report, for the first time, the importance of Nod1 for mediating trophoblast IL-1β secretion in response to a Ct infection.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • CARD Signaling Adaptor Proteins
  • Carrier Proteins / metabolism
  • Cell Line
  • Chlamydia trachomatis / immunology*
  • Cytoskeletal Proteins / metabolism
  • Gene Expression
  • Humans
  • Inflammasomes / metabolism
  • Interleukin-1beta / genetics
  • Interleukin-1beta / metabolism*
  • Myeloid Differentiation Factor 88 / metabolism
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Nod1 Signaling Adaptor Protein / metabolism*
  • Toll-Like Receptor 2 / metabolism
  • Toll-Like Receptor 4 / metabolism
  • Trophoblasts / metabolism*
  • Trophoblasts / microbiology*


  • CARD Signaling Adaptor Proteins
  • Carrier Proteins
  • Cytoskeletal Proteins
  • Inflammasomes
  • Interleukin-1beta
  • Myeloid Differentiation Factor 88
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • NLRP3 protein, human
  • Nod1 Signaling Adaptor Protein
  • PYCARD protein, human
  • Toll-Like Receptor 2
  • Toll-Like Receptor 4