Predicting novel features of toll-like receptor 3 signaling in macrophages

• Published in: PloS one 2009-03, Vol.4 (3), p.e4661-e4661
• Main Authors: Helmy, Mohamed, Gohda, Jin, Inoue, Jun-Ichiro, Tomita, Masaru, Tsuchiya, Masa, Selvarajoo, Kumar
• Format: Article
• Language: English
• Subjects: Analysis; Animal models; Animals; B cells; Biochemistry/Bioinformatics; Bioinformatics; Biophysics; Cell activation; Computational Biology; Computer applications; Computer simulation; Cytokines; Double-stranded RNA; Encyclopedias; Genomes; Growth factors; Health aspects; Immune response; Immune system; Immunology; Inflammation; Innate immunity; Interferon; International conferences; Intracellular; Intracellular signalling; JNK protein; Kinases; Macrophages; Macrophages - metabolism; Mathematical models; Mice; Model testing; Molecular biology; Molecular modelling; NF-κB protein; Perturbation methods; Phosphotransferases; Poly (I:C); Polyinosinic:polycytidylic acid; Proteins; Ribonucleic acid; RNA; Signal Transduction; TLR3 protein; Toll-Like Receptor 3 - metabolism; Toll-like receptors; Topology; TRAF6 protein; Transcription factors; Trends; Virus diseases
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0004661

The Toll-like receptor (TLR) 3 plays a critical role in mammalian innate immune response against viral attacks by recognizing double-stranded RNA (dsRNA) or its synthetic analog polyinosinic-polycytidylic acid (poly (IratioC)). This leads to the activation of MAP kinases and NF-kappaB which results in the induction of type I interferons and proinflammatory cytokines to combat the viral infection. To understand the complex interplay of the various intracellular signaling molecules in the regulation of NF-kappaB and MAP kinases, we developed a computational TLR3 model based upon perturbation-response approach. We curated literature and databases to determine the TLR3 signaling topology specifically for murine macrophages. For initial model creation, we used wildtype temporal activation profiles of MAP kinases and NF-kappaB and, for model testing, used TRAF6 KO and TRADD KO data. From dynamic simulations we predict i) the existence of missing intermediary steps between extracellular poly (IratioC) stimulation and intracellular TLR3 binding, and ii) the presence of a novel pathway which is essential for JNK and p38, but not NF-kappaB, activation. Our work shows activation dynamics of signaling molecules can be used in conjunction with perturbation-response models to decipher novel signaling features of complicated immune pathways.