Establishment of a monoclonal antibody against human Toll-like receptor 3 that blocks double-stranded RNA-mediated signaling

Biochem Biophys Res Commun. 2002 May 24;293(5):1364-9. doi: 10.1016/S0006-291X(02)00380-7.


A monoclonal antibody (mAb) against human Toll-like receptor (TLR) 3 was established and its effect on TLR3-mediated responses was tested using human fibroblast cell lines expressing TLR3 on the cell surface. Fibroblasts are known to produce IFN-beta upon viral infection or treatment with double-stranded RNA (dsRNA) through distinct signaling pathways. Here, we show the mAb to TLR3 suppressed poly(I):poly(C)-mediated IFN-beta production by human fibroblasts naturally expressing TLR3 on their surface. By reporter gene assay using HEK293 cells transfected with a human TLR3 expression vector, TLR3 recognized dsRNA to activate NF-kappaB and the IFN-beta promoter. TLR3 signaling was not elicited by either single-stranded RNA (ssRNA) or dsDNA. Thus, specific recognition of dsRNA by extracellular TLR3 is essential for induction of type I IFN: the interassociation between dsRNA and TLR3, regardless of direct or indirect binding, should be disrupted by mAb being attached to TLR3. The mAb against TLR3 reported herein may serve as a regulator for virus-mediated immune response via an alternative pathway involving the dsRNA-TLR3 recognition which might occur on host cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal / metabolism*
  • Cell Line
  • Cell Membrane / metabolism
  • DNA, Complementary / metabolism
  • Dose-Response Relationship, Drug
  • Drosophila Proteins*
  • Fibroblasts / metabolism
  • Flow Cytometry
  • Genes, Reporter
  • Genetic Vectors
  • Humans
  • Interferon-beta / metabolism
  • Luciferases / metabolism
  • Lung / metabolism
  • Membrane Glycoproteins / chemistry
  • Membrane Glycoproteins / immunology*
  • Mice
  • Mice, Inbred BALB C
  • NF-kappa B / metabolism
  • Promoter Regions, Genetic
  • Protein Binding
  • RNA / metabolism*
  • RNA, Double-Stranded / metabolism
  • Receptors, Cell Surface / chemistry
  • Receptors, Cell Surface / immunology*
  • Recombinant Proteins / metabolism
  • Signal Transduction
  • Toll-Like Receptor 3
  • Toll-Like Receptors
  • Transfection


  • Antibodies, Monoclonal
  • DNA, Complementary
  • Drosophila Proteins
  • Membrane Glycoproteins
  • NF-kappa B
  • RNA, Double-Stranded
  • Receptors, Cell Surface
  • Recombinant Proteins
  • TLR3 protein, human
  • Toll-Like Receptor 3
  • Toll-Like Receptors
  • RNA
  • Interferon-beta
  • Luciferases