The Experts below are selected from a list of 133443 Experts worldwide ranked by ideXlab platform
Thomas M P Gilbert - One of the best experts on this subject based on the ideXlab platform.
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the vertebrate tlr supergene family evolved dynamically by gene gain loss and positive selection revealing a host pathogen arms race in birds
Diversity, 2019Co-Authors: Imran Khan, Emanuel Maldonado, Liliana Silva, Daniela Almeida, Warren E Johnson, Stephen James Obrien, Guojie Zhang, Erich D Jarvis, Thomas M P GilbertAbstract:The vertebrate toll-like receptor (TLRs) supergene family is a first-line immune defense against viral and non-viral pathogens. Here, comparative evolutionary-genomics of 79 vertebrate species (8 mammals, 48 birds, 11 reptiles, 1 amphibian, and 11 fishes) revealed differential gain/loss of 26 TLRs, including 6 (TLR3, TLR7, TLR8, TLR14, TLR21, and TLR22) that originated early in vertebrate evolution before the diversification of Agnatha and Gnathostomata. Subsequent dynamic gene gain/loss led to lineage-specific diversification with TLR repertoires ranging from 8 subfamilies in birds to 20 in fishes. Lineage-specific loss of TLR8-9 and TLR13 in birds and gains of TLR6 and TLR10-12 in mammals and TLR19-20 and TLR23-27 in fishes. Among avian species, 5–10% of the sites were under positive selection (PS) (omega 1.5–2.5) with radical amino-acid changes likely affecting TLR structure/functionality. In non-viral TLR4 the 20 PS sites (posterior probability PP > 0.99) likely increased ability to cope with diversified ligands (e.g., lipopolysaccharide and lipoteichoic). For viral TLR7, 23 PS sites (PP > 0.99) possibly improved recognition of highly variable viral ssRNAs. Rapid evolution of the TLR supergene family reflects the host–pathogen arms race and the coevolution of ligands/receptors, which follows the premise that birds have been important vectors of zoonotic pathogens and reservoirs for viruses.
Erich D Jarvis - One of the best experts on this subject based on the ideXlab platform.
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the vertebrate tlr supergene family evolved dynamically by gene gain loss and positive selection revealing a host pathogen arms race in birds
Diversity, 2019Co-Authors: Imran Khan, Emanuel Maldonado, Liliana Silva, Daniela Almeida, Warren E Johnson, Stephen James Obrien, Guojie Zhang, Erich D Jarvis, Thomas M P GilbertAbstract:The vertebrate toll-like receptor (TLRs) supergene family is a first-line immune defense against viral and non-viral pathogens. Here, comparative evolutionary-genomics of 79 vertebrate species (8 mammals, 48 birds, 11 reptiles, 1 amphibian, and 11 fishes) revealed differential gain/loss of 26 TLRs, including 6 (TLR3, TLR7, TLR8, TLR14, TLR21, and TLR22) that originated early in vertebrate evolution before the diversification of Agnatha and Gnathostomata. Subsequent dynamic gene gain/loss led to lineage-specific diversification with TLR repertoires ranging from 8 subfamilies in birds to 20 in fishes. Lineage-specific loss of TLR8-9 and TLR13 in birds and gains of TLR6 and TLR10-12 in mammals and TLR19-20 and TLR23-27 in fishes. Among avian species, 5–10% of the sites were under positive selection (PS) (omega 1.5–2.5) with radical amino-acid changes likely affecting TLR structure/functionality. In non-viral TLR4 the 20 PS sites (posterior probability PP > 0.99) likely increased ability to cope with diversified ligands (e.g., lipopolysaccharide and lipoteichoic). For viral TLR7, 23 PS sites (PP > 0.99) possibly improved recognition of highly variable viral ssRNAs. Rapid evolution of the TLR supergene family reflects the host–pathogen arms race and the coevolution of ligands/receptors, which follows the premise that birds have been important vectors of zoonotic pathogens and reservoirs for viruses.
Genhong Cheng - One of the best experts on this subject based on the ideXlab platform.
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irf3 mediates a tlr3 tlr4 specific antiviral gene program
Immunity, 2002Co-Authors: Sean E Doyle, Sagar A Vaidya, Ryan M Oconnell, Hajir Dadgostar, Paul W Dempsey, Margaret E Haberland, Robert L Modlin, Tingting Wu, Genhong ChengAbstract:We have identified a subset of genes that is specifically induced by stimulation of TLR3 or TLR4 but not by TLR2 or TLR9. Further gene expression analyses established that upregulation of several primary response genes was dependent on NF-kappaB, commonly activated by several TLRs, and interferon regulatory factor 3 (IRF3), which was found to confer TLR3/TLR4 specificity. Also identified was a group of secondary response genes which are part of an autocrine/paracrine loop activated by the primary response gene product, interferon beta (IFNbeta). Selective activation of the TLR3/TLR4-IRF3 pathway potently inhibited viral replication. These results suggest that TLR3 and TLR4 have evolutionarily diverged from other TLRs to activate IRF3, which mediates a specific gene program responsible for innate antiviral responses.
Imran Khan - One of the best experts on this subject based on the ideXlab platform.
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the vertebrate tlr supergene family evolved dynamically by gene gain loss and positive selection revealing a host pathogen arms race in birds
Diversity, 2019Co-Authors: Imran Khan, Emanuel Maldonado, Liliana Silva, Daniela Almeida, Warren E Johnson, Stephen James Obrien, Guojie Zhang, Erich D Jarvis, Thomas M P GilbertAbstract:The vertebrate toll-like receptor (TLRs) supergene family is a first-line immune defense against viral and non-viral pathogens. Here, comparative evolutionary-genomics of 79 vertebrate species (8 mammals, 48 birds, 11 reptiles, 1 amphibian, and 11 fishes) revealed differential gain/loss of 26 TLRs, including 6 (TLR3, TLR7, TLR8, TLR14, TLR21, and TLR22) that originated early in vertebrate evolution before the diversification of Agnatha and Gnathostomata. Subsequent dynamic gene gain/loss led to lineage-specific diversification with TLR repertoires ranging from 8 subfamilies in birds to 20 in fishes. Lineage-specific loss of TLR8-9 and TLR13 in birds and gains of TLR6 and TLR10-12 in mammals and TLR19-20 and TLR23-27 in fishes. Among avian species, 5–10% of the sites were under positive selection (PS) (omega 1.5–2.5) with radical amino-acid changes likely affecting TLR structure/functionality. In non-viral TLR4 the 20 PS sites (posterior probability PP > 0.99) likely increased ability to cope with diversified ligands (e.g., lipopolysaccharide and lipoteichoic). For viral TLR7, 23 PS sites (PP > 0.99) possibly improved recognition of highly variable viral ssRNAs. Rapid evolution of the TLR supergene family reflects the host–pathogen arms race and the coevolution of ligands/receptors, which follows the premise that birds have been important vectors of zoonotic pathogens and reservoirs for viruses.
Jack L Strominger - One of the best experts on this subject based on the ideXlab platform.
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il 10 released by concomitant tlr2 stimulation blocks the induction of a subset of th1 cytokines that are specifically induced by tlr4 or tlr3 in human dendritic cells
Journal of Immunology, 2004Co-Authors: Fabio Re, Jack L StromingerAbstract:Recognition of microbial products through TLRs triggers the expression of several cytokines that regulate innate and adaptive immunity. Signaling by various TLRs is not equivalent and leads to differential gene induction. This study analyzed the responses of human dendritic cells (DCs) and PBMCs stimulated with agonists of TLR2, TLR3, TLR4, TLR5, and TLR7, first individually and then in combination. Several cytokines were equally induced by all TLR agonists, but four genes, IFN-β, IFN-γ-inducible protein 10 (IP-10), IL-12p35, and IL-15, showed a very restricted pattern of induction. Thus, each TLR appears to possess a distinctive ability to activate DCs or PBMCs, suggesting that TLR-mediated responses cannot be simply cataloged as resembling either TLR2 (MyD88 dependent) or TLR4 (MyD88 independent) and that other signaling modalities may exist. The analysis of DC and PBMC activation by combinations of TLR agonists revealed that TLR2 agonists are able to block the induction of IP-10, IL-12p35, and IFN-γ, but not IL-15 and IFN-β, by TLR3 and TLR4. TLR2 stimulation led to rapid release of IL-10 that is responsible for inhibition of IP-10 and IL-12p35 induction. Cross-talk between different TLRs may modify the primary responses of TLR to their agonist, adding a further level of complexity to the regulation of innate immunity.
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il 10 released by concomitant tlr2 stimulation blocks the induction of a subset of th1 cytokines that are specifically induced by tlr4 or tlr3 in human dendritic cells
Journal of Immunology, 2004Co-Authors: Jack L StromingerAbstract:Recognition of microbial products through TLRs triggers the expression of several cytokines that regulate innate and adaptive immunity. Signaling by various TLRs is not equivalent and leads to differential gene induction. This study analyzed the responses of human dendritic cells (DCs) and PBMCs stimulated with agonists of TLR2, TLR3, TLR4, TLR5, and TLR7, first individually and then in combination. Several cytokines were equally induced by all TLR agonists, but four genes, IFN-beta, IFN-gamma-inducible protein 10 (IP-10), IL-12p35, and IL-15, showed a very restricted pattern of induction. Thus, each TLR appears to possess a distinctive ability to activate DCs or PBMCs, suggesting that TLR-mediated responses cannot be simply cataloged as resembling either TLR2 (MyD88 dependent) or TLR4 (MyD88 independent) and that other signaling modalities may exist. The analysis of DC and PBMC activation by combinations of TLR agonists revealed that TLR2 agonists are able to block the induction of IP-10, IL-12p35, and IFN-gamma, but not IL-15 and IFN-beta, by TLR3 and TLR4. TLR2 stimulation led to rapid release of IL-10 that is responsible for inhibition of IP-10 and IL-12p35 induction. Cross-talk between different TLRs may modify the primary responses of TLR to their agonist, adding a further level of complexity to the regulation of innate immunity.
