Role of Toll-Like Receptors in Pathogen Recognition
Sophie Janssens,Rudi Beyaert +1 more
TLDR
The Toll-like receptors are a recently discovered family of pattern recognition receptors which show homology with the Drosophila Toll protein and the human interleukin-1 receptor family, and evidence for some endogenous ligands that might signal other danger conditions has been obtained.Abstract:
The innate immune system relies on a vast array of non-clonally expressed pattern recognition receptors for the detection of pathogens. Pattern recognition receptors bind conserved molecular structures shared by large groups of pathogens, termed pathogen-associated molecular patterns. The Toll-like receptors (TLRs) are a recently discovered family of pattern recognition receptors which show homology with the Drosophila Toll protein and the human interleukin-1 receptor family. Engagement of different TLRs can induce overlapping yet distinct patterns of gene expression that contribute to an inflammatory response. The TLR family is characterized by the presence of leucine-rich repeats and a Toll/interleukin-1 receptor-like domain, which mediate ligand binding and interaction with intracellular signaling proteins, respectively. Most TLR ligands identified so far are conserved microbial products which signal the presence of an infection, but evidence for some endogenous ligands that might signal other danger conditions has also been obtained. Molecular mechanisms for pathogen-associated molecular pattern recognition still remain elusive but seem to be more complicated than initially anticipated. In most cases, direct binding of microbial ligands to TLRs still has to be demonstrated. Moreover, Drosophila TLRs bind endogenous ligands, generated through a proteolytic cascade in response to an infection. In the case of endotoxin, recognition involves a complex of TLR4 and a number of other proteins. Moreover, TLR heterodimerization further extends the spectrum of ligands and modulates the response towards specific ligands. The fact that TLR expression is regulated in both a cell type- and stimulus-dependent fashion further contributes to the complexity.read more
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A Comparative Review of Toll-Like Receptor 4 Expression and Functionality in Different Animal Species
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TL;DR: Current knowledge on the critical points of divergence between human and the mammalian species commonly used in vaccine research and development are focused on, in terms of molecular, cellular, and functional properties of TLR4.
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TL;DR: The mechanisms by which dysfunctional adipose tissue simultaneously promote T2DM and CVD, focusing on adipose tissues depot-specific adipokines, inflammatory profiles, and metabolism, will be the focus of this review.
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Husam Ghanim,Sanaa Abuaysheh,Ching Ling Sia,Kelly Korzeniewski,Ajay Chaudhuri,José Manuel Fernández-Real,Paresh Dandona +6 more
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Is Q Fever an emerging or re-emerging zoonosis?
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References
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Journal ArticleDOI
Innate Immune Recognition
TL;DR: Microbial recognition by Toll-like receptors helps to direct adaptive immune responses to antigens derived from microbial pathogens to distinguish infectious nonself from noninfectious self.
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Defective LPS Signaling in C3H/HeJ and C57BL/10ScCr Mice: Mutations in Tlr4 Gene
Alexander Poltorak,Xiaolong He,Irina Smirnova,Mu Ya Liu,Christophe Van Huffel,Xin Du,Dale Birdwell,E. Alejos,M. Silva,Chris Galanos,Marina Freudenberg,Paola Ricciardi-Castagnoli,Betsy Layton,Bruce Beutler +13 more
TL;DR: The mammalian Tlr4 protein has been adapted primarily to subserve the recognition of LPS and presumably transduces the LPS signal across the plasma membrane.
Journal Article
Defective LPS signaling in C3 H/HeJ and C57 BL/10 ScCr mice: Mutations in Tlr4 Gene
Alexander Poltorak,Xiaolong He,Irina Smirnova,Mu Ya Liu,C. Van Huffel,Xin Du,Dale Birdwell,E. Alejos,M. Suva,Chris Galanos,Marina Freudenberg,Paola Ricciardi-Castagnoli,B. Layton,Bruce Beutler +13 more
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A Toll-like receptor recognizes bacterial DNA.
Hiroaki Hemmi,Osamu Takeuchi,Taro Kawai,Tsuneyasu Kaisho,Shintaro Sato,Hideki Sanjo,Makoto Matsumoto,Katsuaki Hoshino,Hermann Wagner,Kiyoshi Takeda,Shizuo Akira +10 more
TL;DR: It is shown that cellular response to CpG DNA is mediated by a Toll-like receptor, TLR9, and vertebrate immune systems appear to have evolved a specific Toll- like receptor that distinguishes bacterial DNA from self-DNA.
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Recognition of double-stranded RNA and activation of NF-kappaB by Toll-like receptor 3.
TL;DR: It is shown that mammalian TLR3 recognizes dsRNA, and that activation of the receptor induces the activation of NF-κB and the production of type I interferons (IFNs).