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Updated: Jun 25, 2026
A Macrophage Reporter Cell Assay to Examine Toll-Like Receptor-Mediated NF-kB/AP-1 Signaling on Adsorbed Protein Layers on Polymeric Surfaces
Published on: January 7, 2020
Predicting novel features of toll-like receptor 3 signaling in macrophages
Mohamed Helmy1, Jin Gohda, Jun-Ichiro Inoue
1Institute for Advanced Biosciences, Keio University, Tsuruoka, Japan.
Abstract:
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.
Insights
Computational modeling of Toll-like receptor 3 (TLR3) signaling reveals missing steps and a novel pathway. This advance enhances understanding of innate immunity against viral infections by analyzing immune cell responses.
Area of Science:
- Immunology
- Computational Biology
- Systems Biology
Background:
- Toll-like receptor 3 (TLR3) is crucial for innate immunity against viruses, recognizing double-stranded RNA (dsRNA).
- TLR3 activation triggers MAP kinases and NF-kappaB, inducing type I interferons and cytokines to fight viral infections.
- Understanding the complex intracellular signaling network regulating TLR3 is vital.
Purpose of the Study:
- To develop a computational model of TLR3 signaling in murine macrophages using a perturbation-response approach.
- To elucidate the intricate interplay of intracellular signaling molecules involved in TLR3-mediated immune responses.
- To identify novel signaling features and missing regulatory steps within the TLR3 pathway.
Main Methods:
- Literature and database curation to establish TLR3 signaling topology in murine macrophages.
- Development of a computational model based on the perturbation-response methodology.
- Utilizing wildtype temporal activation profiles and knockout (KO) data (TRAF6 KO, TRADD KO) for model creation and testing.
Main Results:
- Dynamic simulations predicted the existence of previously unidentified intermediary steps between extracellular poly(I:C) stimulation and intracellular TLR3 binding.
- A novel signaling pathway essential for JNK and p38 activation, but not NF-kappaB, was identified.
- The model successfully predicted key signaling dynamics, validating its predictive power.
Conclusions:
- Computational modeling combined with perturbation-response data can uncover novel signaling mechanisms in complex immune pathways.
- The study identified missing links and a new pathway in TLR3 signaling, advancing our understanding of antiviral innate immunity.
- Activation dynamics of signaling molecules offer valuable insights into immune pathway regulation.
