Establishment of a monoclonal antibody against human Toll-like receptor 3 that blocks double-stranded RNA-mediated signaling.
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.
Matsumoto
Misako
M
Department of Immunology, Osaka Medical Center for Cancer and Cardiovascular Diseases, 1-3-2 Nakamichi, Higashinari-ku, Osaka 537-8511, Japan.
Kikkawa
Satomi
S
Kohase
Masayoshi
M
Miyake
Kensuke
K
Seya
Tsukasa
T
D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D029721:Drosophila Proteins; D005347:Fibroblasts / Q000378:metabolism; D005434:Flow Cytometry; D017930:Genes, Reporter; D005822:Genetic Vectors; D006801:Humans; D016899:Interferon-beta / Q000378:metabolism; D008156:Luciferases / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D016328:NF-kappa B / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012313:RNA / Q000378:metabolism*; D012330:RNA, Double-Stranded / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000276:immunology*; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction; D051196:Toll-Like Receptor 3; D051193:Toll-Like Receptors; D014162:Transfection
D000911:Antibodies, Monoclonal; D018076:DNA, Complementary; D029721:Drosophila Proteins; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D012330:RNA, Double-Stranded; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; C495344:TLR3 protein, human; D051196:Toll-Like Receptor 3; D051193:Toll-Like Receptors; D012313:RNA; D016899:Interferon-beta; D008156:Luciferases