Tim-3 protects decidual stromal cells from toll-like receptor-mediated apoptosis and inflammatory reactions and promotes Th2 bias at the maternal-fetal interface

Sci Rep. 2015 Mar 11:5:9013. doi: 10.1038/srep09013.

Abstract

Toll-like receptors (TLRs) are important in mediating immune responses against various pathogens during pregnancy. However, uncontrolled TLR-triggered inflammation will endanger normal pregnancy, resulting in pregnancy loss. Therefore, maintenance of a moderate inflammatory response is crucial for successful pregnancy under conditions of infection. Here, we demonstrated significantly lowered expression of T-cell immunoglobulin and mucin domain 3 (Tim-3) in miscarried decidual stromal cells (DSCs), indicating that Tim-3 might play important roles in maintaining successful pregnancies. Activation of TLR signaling induced pro-inflammatory cytokine production and apoptosis of DSCs, which was accompanied by up-regulated Tim-3 expression. Tim-3, in turn, protected DSCs from TLR-mediated apoptosis in an ERK1/2 pathway-dependent manner. In addition, Tim-3 inhibited TLR signaling-induced inflammatory cytokine production by DSCs through suppressing NF-κB activation. Tim-3 increased production of T helper 2 (Th2)-type cytokines by DSCs and reversed the inhibitory effect of LPS on Th2 cytokine generation by up-regulation of interferon regulatory factor 4 expression. Tim-3 blockade abolished the effect of Tim-3 on the inflammatory response to LPS stimulation. Thus, Tim-3 signaling could represent a "self-control" mechanism in TLR-triggered inflammation during pregnancy. These findings identify Tim-3 as a key regulator of DSCs and suggest its potential as a target for the treatment of spontaneous abortion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abortion, Spontaneous / genetics
  • Abortion, Spontaneous / immunology
  • Abortion, Spontaneous / metabolism
  • Apoptosis* / genetics
  • Cytokines / metabolism
  • Decidua / immunology*
  • Decidua / metabolism*
  • Down-Regulation
  • Female
  • Gene Expression Regulation
  • Hepatitis A Virus Cellular Receptor 2
  • Humans
  • Inflammation / immunology*
  • Inflammation / metabolism*
  • Inflammation Mediators / metabolism
  • MAP Kinase Signaling System
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Models, Biological
  • NF-kappa B / metabolism
  • Placenta / immunology
  • Placenta / metabolism
  • Pregnancy
  • Signal Transduction
  • Stromal Cells / metabolism*
  • Th2 Cells / immunology*
  • Th2 Cells / metabolism
  • Toll-Like Receptors / metabolism*

Substances

  • Cytokines
  • HAVCR2 protein, human
  • Hepatitis A Virus Cellular Receptor 2
  • Inflammation Mediators
  • Membrane Proteins
  • NF-kappa B
  • Toll-Like Receptors