1
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Jin Q, Ren F, Song P. Innovate therapeutic targets for autoimmune diseases: insights from proteome-wide mendelian randomization and Bayesian colocalization. Autoimmunity 2024; 57:2330392. [PMID: 38515381 DOI: 10.1080/08916934.2024.2330392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 03/10/2024] [Indexed: 03/23/2024]
Abstract
BACKGROUND Despite growing knowledge regarding the pathogenesis of autoimmune diseases (ADs) onset, the current treatment remains unsatisfactory. This study aimed to identify innovative therapeutic targets for ADs through various analytical approaches. RESEARCH DESIGN AND METHODS Utilizing Mendelian randomization, Bayesian co-localization, phenotype scanning, and protein-protein interaction network, we explored potential therapeutic targets for 14 ADs and externally validated our preliminary findings. RESULTS This study identified 12 circulating proteins as potential therapeutic targets for six ADs. Specifically, IL12B was judged to be a risk factor for ankylosing spondylitis (p = 1.61E - 07). TYMP (p = 6.28E - 06) was identified as a protective factor for ulcerative colitis. For Crohn's disease, ERAP2 (p = 4.47E - 14), HP (p = 2.08E - 05), and RSPO3 (p = 6.52E - 07), were identified as facilitators, whereas FLRT3 (p = 3.42E - 07) had a protective effect. In rheumatoid arthritis, SWAP70 (p = 3.26E - 10), SIGLEC6 (p = 2.47E - 05), ISG15 (p = 3.69E - 05), and FCRL3 (p = 1.10E - 10) were identified as risk factors. B4GALT1 (p = 6.59E - 05) was associated with a lower risk of Type 1 diabetes (T1D). Interestingly, CTSH was identified as a protective factor for narcolepsy (p = 1.58E - 09) but a risk factor for T1D (p = 7.36E - 11), respectively. External validation supported the associations of eight of these proteins with three ADs. CONCLUSIONS Our integrated study identified 12 potential therapeutic targets for ADs and provided novel insights into future drug development for ADs.
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Affiliation(s)
- Qiubai Jin
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Feihong Ren
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- Graduate school, Beijing University of Chinese Medicine, Beijing, China
| | - Ping Song
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
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2
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Temple H, Donnelly B, Mohanty SK, Mowery S, Poling HM, Pasula R, Hartman S, Singh A, Mourya R, Bondoc A, Meller J, Jegga AG, Oyama K, McNeal M, Spearman P, Tiao G. Specific binding sites on Rhesus rotavirus capsid protein dictate the method of endocytosis inducing the murine model of biliary atresia. Am J Physiol Gastrointest Liver Physiol 2024; 327:G267-G283. [PMID: 38860860 DOI: 10.1152/ajpgi.00308.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 05/17/2024] [Accepted: 05/28/2024] [Indexed: 06/12/2024]
Abstract
Biliary atresia (BA) is the leading indication for pediatric liver transplantation. Rhesus rotavirus (RRV)-induced murine BA develops an obstructive cholangiopathy that mirrors the human disease. We have previously demonstrated the "SRL" motif on RRV's VP4 protein binds to heat shock cognate 70 protein (Hsc70) facilitating entry into cholangiocytes. In this study, we analyzed how binding to Hsc70 affects viral endocytosis, intracellular trafficking, and uniquely activates the signaling pathway that induces murine BA. Inhibition of clathrin- and dynamin-mediated endocytosis in cholangiocytes following infection demonstrated that blocking dynamin decreased the infectivity of RRV, whereas clathrin inhibition had no effect. Blocking early endosome trafficking resulted in decreased viral titers of RRV, whereas late endosome inhibition had no effect. After infection, TLR3 expression and p-NF-κB levels increased in cholangiocytes, leading to increased release of CXCL9 and CXCL10. Infected mice knocked out for TLR3 had decreased levels of CXCL9 and CXCL10, resulting in reduced NK cell numbers. Human patients with BA experienced an increase in CXCL10 levels, suggesting this as a possible pathway leading to biliary obstruction. Viruses that use Hsc70 for cell entry exploit a clathrin-independent pathway and traffic to the early recycling endosome uniquely activating NF-κB through TLR3, leading to the release of CXCL9 and CXCL10 and inducing NK cell recruitment. These results define how the "SRL" peptide found on RRV's VP4 protein modulates viral trafficking, inducing the host response leading to bile duct obstruction.NEW & NOTEWORTHY In this study, we have determined that the presence of the "SRL" peptide on RRV alters its method of endocytosis and intracellular trafficking through viral binding to heat shock cognate 70 protein. This initiates an inflammatory pathway that stimulates the release of cytokines associated with biliary damage and obstruction.
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Affiliation(s)
- Haley Temple
- Department of Pediatric and Thoracic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Bryan Donnelly
- Department of Pediatric and Thoracic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Sujit K Mohanty
- Southeast Poultry Research Laboratory, United States National Poultry Research Center, United States Department of Agriculture, Athens, Georgia, United States
| | - Sarah Mowery
- Department of Pediatric and Thoracic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Holly M Poling
- Department of Pediatric and Thoracic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Rajamouli Pasula
- Department of Pediatric and Thoracic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Stephen Hartman
- Department of Pediatric and Thoracic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Akaljot Singh
- Department of Pediatric and Thoracic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Reena Mourya
- Division of Gastroenterology, Hepatology and Nutrition, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Alexander Bondoc
- Department of Pediatric and Thoracic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Jaroslaw Meller
- Department of Environmental and Public Health Sciences, University of Cincinnati, Cincinnati, Ohio, United States
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Anil G Jegga
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Kei Oyama
- Department of Pediatric and Thoracic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Monica McNeal
- Division of Infectious Diseases, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States
| | - Paul Spearman
- Division of Infectious Diseases, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States
| | - Greg Tiao
- Department of Pediatric and Thoracic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
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3
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Song Z, Li S, Shang Z, Lv W, Cheng X, Meng X, Chen R, Zhang S, Zhang R. Integrating multi-omics data to analyze the potential pathogenic mechanism of CTSH gene involved in type 1 diabetes in the exocrine pancreas. Brief Funct Genomics 2024; 23:406-417. [PMID: 38050341 DOI: 10.1093/bfgp/elad052] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 10/19/2023] [Accepted: 11/09/2023] [Indexed: 12/06/2023] Open
Abstract
Type 1 diabetes (T1D) is an autoimmune disease caused by the destruction of insulin-producing pancreatic islet beta cells. Despite significant advancements, the precise pathogenesis of the disease remains unknown. This work integrated data from expression quantitative trait locus (eQTL) studies with Genome wide association study (GWAS) summary data of T1D and single-cell transcriptome data to investigate the potential pathogenic mechanisms of the CTSH gene involved in T1D in exocrine pancreas. Using the summary data-based Mendelian randomization (SMR) approach, we obtained four potential causative genes associated with T1D: BTN3A2, PGAP3, SMARCE1 and CTSH. To further investigate these genes'roles in T1D development, we validated them using a scRNA-seq dataset from pancreatic tissues of both T1D patients and healthy controls. The analysis showed a significantly high expression of the CTSH gene in T1D acinar cells, whereas the other three genes showed no significant changes in the scRNA-seq data. Moreover, single-cell WGCNA analysis revealed the strongest positive correlation between the module containing CTSH and T1D. In addition, we found cellular ligand-receptor interactions between the acinar cells and different cell types, especially ductal cells. Finally, based on functional enrichment analysis, we hypothesized that the CTSH gene in the exocrine pancreas enhances the antiviral response, leading to the overexpression of pro-inflammatory cytokines and the development of an inflammatory microenvironment. This process promotes β cells injury and ultimately the development of T1D. Our findings offer insights into the underlying pathogenic mechanisms of T1D.
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Affiliation(s)
- Zerun Song
- College of Bioinformatics Science and Technology, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin City, Heilongjiang Province, China
| | - Shuai Li
- College of Bioinformatics Science and Technology, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin City, Heilongjiang Province, China
| | - Zhenwei Shang
- College of Bioinformatics Science and Technology, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin City, Heilongjiang Province, China
| | - Wenhua Lv
- College of Bioinformatics Science and Technology, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin City, Heilongjiang Province, China
| | - Xiangshu Cheng
- College of Bioinformatics Science and Technology, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin City, Heilongjiang Province, China
| | - Xin Meng
- College of Bioinformatics Science and Technology, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin City, Heilongjiang Province, China
| | - Rui Chen
- College of Bioinformatics Science and Technology, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin City, Heilongjiang Province, China
| | - Shuhao Zhang
- College of Bioinformatics Science and Technology, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin City, Heilongjiang Province, China
| | - Ruijie Zhang
- College of Bioinformatics Science and Technology, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin City, Heilongjiang Province, China
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4
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Pejler G, Zhao XO, Fagerström E, Paivandy A. Blockade of endolysosomal acidification suppresses TLR3-mediated proinflammatory signaling in airway epithelial cells. J Allergy Clin Immunol 2024:S0091-6749(24)00607-9. [PMID: 38906273 DOI: 10.1016/j.jaci.2024.05.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 05/02/2024] [Accepted: 05/10/2024] [Indexed: 06/23/2024]
Abstract
BACKGROUND Endolysosomal compartments are acidic and contain low pH-dependent proteases, and these conditions are exploited by respiratory viruses, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza virus, for escaping into the cytosol. Moreover, endolysosomes contain various pattern recognition receptors (PRRs), which respond to virus-derived pathogen-associated molecular patterns (PAMPs) by production of proinflammatory cytokines/chemokines. However, excessive proinflammatory responses can lead to a potentially lethal cytokine storm. OBJECTIVES Here we investigated the endosomal PRR expression profile in primary human small airway epithelial cells (HSAECs), and whether blockade of endolysosomal acidification affects their cytokine/chemokine production after challenge with virus-derived stimulants. METHODS HSAECs were exposed to stimulants mimicking virus-derived PAMPs, either in the absence or presence of compounds causing blockade of endolysosomal acidification, followed by measurement of cytokine expression and release. RESULTS We show that Toll-like receptor 3 (TLR3) is the major endosomal PRR expressed by HSAECs, and that TLR3 expression is strongly induced by TLR3 agonists, but not by a range of other PRR agonists. We also demonstrate that TLR3 engagement with its agonists elicits a robust proinflammatory cytokine/chemokine response, which is profoundly suppressed through blockade of endolysosomal acidification, by bafilomycin A1, monensin, or niclosamide. Using TLR3 reporter cells, it was confirmed that TLR3 signaling is strongly induced by Poly(I:C) and that blockade of endolysosomal acidification efficiently blocked TLR3 signaling. Finally, we show that blockade of endolysosomal acidification causes a reduction in the levels of TLR3 mRNA and protein. CONCLUSIONS These findings show that blockade of endolysosomal acidification suppresses TLR3-dependent cytokine and chemokine production in HSAECs.
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Affiliation(s)
- Gunnar Pejler
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Xinran O Zhao
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Ella Fagerström
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Aida Paivandy
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
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Lin YS, Chang YC, Chao TL, Tsai YM, Jhuang SJ, Ho YH, Lai TY, Liu YL, Chen CY, Tsai CY, Hsueh YP, Chang SY, Chuang TH, Lee CY, Hsu LC. The Src-ZNRF1 axis controls TLR3 trafficking and interferon responses to limit lung barrier damage. J Exp Med 2023; 220:214096. [PMID: 37158982 PMCID: PMC10174191 DOI: 10.1084/jem.20220727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 01/23/2023] [Accepted: 03/02/2023] [Indexed: 05/10/2023] Open
Abstract
Type I interferons are important antiviral cytokines, but prolonged interferon production is detrimental to the host. The TLR3-driven immune response is crucial for mammalian antiviral immunity, and its intracellular localization determines induction of type I interferons; however, the mechanism terminating TLR3 signaling remains obscure. Here, we show that the E3 ubiquitin ligase ZNRF1 controls TLR3 sorting into multivesicular bodies/lysosomes to terminate signaling and type I interferon production. Mechanistically, c-Src kinase activated by TLR3 engagement phosphorylates ZNRF1 at tyrosine 103, which mediates K63-linked ubiquitination of TLR3 at lysine 813 and promotes TLR3 lysosomal trafficking and degradation. ZNRF1-deficient mice and cells are resistant to infection by encephalomyocarditis virus and SARS-CoV-2 because of enhanced type I interferon production. However, Znrf1-/- mice have exacerbated lung barrier damage triggered by antiviral immunity, leading to enhanced susceptibility to respiratory bacterial superinfections. Our study highlights the c-Src-ZNRF1 axis as a negative feedback mechanism controlling TLR3 trafficking and the termination of TLR3 signaling.
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Affiliation(s)
- You-Sheng Lin
- Institute of Molecular Medicine, College of Medicine, National Taiwan University , Taipei, Taiwan
| | - Yung-Chi Chang
- Institute of Molecular Medicine, College of Medicine, National Taiwan University , Taipei, Taiwan
| | - Tai-Ling Chao
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan
- Genomics Research Center, Academia Sinica , Taipei, Taiwan
| | - Ya-Min Tsai
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Shu-Jhen Jhuang
- Department of Pathology and Laboratory Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Yu-Hsin Ho
- Institute of Molecular Medicine, College of Medicine, National Taiwan University , Taipei, Taiwan
| | - Ting-Yu Lai
- Institute of Molecular Medicine, College of Medicine, National Taiwan University , Taipei, Taiwan
| | - Yi-Ling Liu
- Immunology Research Center, National Health Research Institutes , Zhunan, Taiwan
| | - Chiung-Ya Chen
- Institute of Molecular Biology, Academia Sinica , Taipei, Taiwan
| | - Ching-Yen Tsai
- Institute of Molecular Biology, Academia Sinica , Taipei, Taiwan
| | - Yi-Ping Hsueh
- Institute of Molecular Biology, Academia Sinica , Taipei, Taiwan
| | - Sui-Yuan Chang
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Tsung-Hsien Chuang
- Immunology Research Center, National Health Research Institutes , Zhunan, Taiwan
| | - Chih-Yuan Lee
- Institute of Molecular Medicine, College of Medicine, National Taiwan University , Taipei, Taiwan
- Department of Surgery, National Taiwan University Hospital, Taipei City, Taiwan
| | - Li-Chung Hsu
- Institute of Molecular Medicine, College of Medicine, National Taiwan University , Taipei, Taiwan
- Graduate Institute of Immunology, College of Medicine, National Taiwan University , Taipei, Taiwan
- Center of Precision Medicine, College of Medicine, National Taiwan University , Taipei, Taiwan
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6
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Sawa T, Endo K, Nakashima A, Tanaka Y, Makabe H, Tanaka S. Procyanidin B2 3,3''-di-O-gallate ameliorates imiquimod-induced skin inflammation by suppressing TLR7 signaling through the inhibition of endosomal acidification in dendritic cells. Int Immunopharmacol 2023; 121:110444. [PMID: 37295030 DOI: 10.1016/j.intimp.2023.110444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/29/2023] [Accepted: 06/01/2023] [Indexed: 06/11/2023]
Abstract
The excessive activation of abnormal T helper 17 (Th17) cells and dendritic cells (DCs) in the dermis and epidermis causes severe inflammation of the skin. Toll-like receptor 7 (TLR7)-located in the endosomes of DCs-recognizes nucleic acids from pathogens as well as imiquimod (IMQ), which plays a crucial role in the pathogenesis of skin inflammation. Procyanidin B2 3,3''-di-O-gallate (PCB2DG), a polyphenol, has been reported to suppress the excessive production of proinflammatory cytokines from T cells. The aim of this study was to demonstrate the inhibitory effect of PCB2DG on skin inflammation and TLR7 signaling in DCs. In vivo studies showed that the clinical symptoms of dermatitis were markedly improved by the oral administration of PCB2DG in mouse dermatitis model caused by IMQ application, accompanied by the suppression of excessive cytokine secretion in the inflamed skin and spleen. In vitro, PCB2DG significantly decreased cytokine production in TLR7- or TLR9 ligand-stimulated bone marrow-derived dendritic cells (BMDCs), suggesting that PCB2DG suppresses endosomal toll-like receptors (TLR) signaling in DCs. The activity of endosomal TLRs depends on endosomal acidification, which was significantly inhibited by PCB2DG in BMDCs. The addition of cAMP, an accelerator of endosomal acidification, abrogated the inhibitory effect of cytokine production by PCB2DG. These results provide a new insight into developing functional foods, including PCB2DG, to improve the symptoms of skin inflammation through the suppression of TLR7 signaling in DCs.
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Affiliation(s)
- Toko Sawa
- Division of Food Science and Biotechnology, Department of Agriculture, Graduate School of Science and Technology, Shinshu University, Minami-minowa, Kami-ina, Nagano 399-4598, Japan
| | - Katsunori Endo
- Division of Food Science and Biotechnology, Department of Science and Technology Agriculture, Graduate School of Medicine, Science and Technology, Shinshu University, Minami-minowa, Kami-ina, Nagano 399-4598, Japan
| | - Akane Nakashima
- Department of Agricultural and Life Science, Faculty of Agriculture, Shinshu University, Minami-minowa, Kami-ina, Nagano 399-4598, Japan
| | - Yuna Tanaka
- Division of Food Science and Biotechnology, Department of Agriculture, Graduate School of Science and Technology, Shinshu University, Minami-minowa, Kami-ina, Nagano 399-4598, Japan
| | - Hidefumi Makabe
- Division of Food Science and Biotechnology, Department of Agriculture, Graduate School of Science and Technology, Shinshu University, Minami-minowa, Kami-ina, Nagano 399-4598, Japan; Division of Food Science and Biotechnology, Department of Science and Technology Agriculture, Graduate School of Medicine, Science and Technology, Shinshu University, Minami-minowa, Kami-ina, Nagano 399-4598, Japan; Department of Agricultural and Life Science, Faculty of Agriculture, Shinshu University, Minami-minowa, Kami-ina, Nagano 399-4598, Japan; Division of Innovative Biomolecular Science, Interdisciplinary Cluster for Cutting Edge, Institute for Biomedical Sciences, Shinshu University, 8304 Minami-minowa Kami-ina, Nagano 399-4598, Japan
| | - Sachi Tanaka
- Division of Food Science and Biotechnology, Department of Agriculture, Graduate School of Science and Technology, Shinshu University, Minami-minowa, Kami-ina, Nagano 399-4598, Japan; Division of Food Science and Biotechnology, Department of Science and Technology Agriculture, Graduate School of Medicine, Science and Technology, Shinshu University, Minami-minowa, Kami-ina, Nagano 399-4598, Japan; Department of Agricultural and Life Science, Faculty of Agriculture, Shinshu University, Minami-minowa, Kami-ina, Nagano 399-4598, Japan.
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7
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Wang Y, Xu H, Sun B. Cathepsin H and cathepsin B of Cynoglossus semilaevis are involved in anti-bacterial immunity against Edwardsiella tarda. FISH & SHELLFISH IMMUNOLOGY 2023; 134:108594. [PMID: 36754156 DOI: 10.1016/j.fsi.2023.108594] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 02/02/2023] [Accepted: 02/04/2023] [Indexed: 06/18/2023]
Abstract
Cathepsin H and Cathepsin B are two lysosomal cysteine proteases participating in various physiological processes including immune responses. In fish, the functional roles of Cathepsin H and Cathepsin B during bacterial infection are less understood. In a previous work, we characterized a Cathepsin B homologue (CsCatB) of half-smooth tongue sole (Cynoglossus semilaevis), an economically valuable fish species in China. In this report, we identified a Cathepsin H homologue (CsCatH) from C. semilaevis. In healthy tongue sole, the transcriptional expression of CsCatH was detected in nine different tissues. Laser scanning confocal microscopic analysis showed that ectopically expressed CsCatH and CsCatB were co-localized with the lysosome. Upon infection by Edwardsiella tarda, a significant fish pathogen which caused a severe fish disease termed edwardsiellosis, the expressions of CsCatH and CsCatB were remarkedly upregulated. The knockdown of CsCatH and CsCatB significantly increased the replication of E. tarda and mitigated E. tarda-induced apoptosis in tongue sole tissues. These findings revealed the importance of CsCatH and CsCatB in anti-bacterial immunity of tongue sole.
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Affiliation(s)
- Yilong Wang
- CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Hang Xu
- CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Boguang Sun
- CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China; Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China.
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8
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Ciaston I, Dobosz E, Potempa J, Koziel J. The subversion of toll-like receptor signaling by bacterial and viral proteases during the development of infectious diseases. Mol Aspects Med 2022; 88:101143. [PMID: 36152458 PMCID: PMC9924004 DOI: 10.1016/j.mam.2022.101143] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/29/2022] [Accepted: 09/09/2022] [Indexed: 02/05/2023]
Abstract
Toll-like receptors (TLRs) are pattern recognition receptors (PRRs) that respond to pathogen-associated molecular patterns (PAMPs). The recognition of specific microbial ligands by TLRs triggers an innate immune response and also promotes adaptive immunity, which is necessary for the efficient elimination of invading pathogens. Successful pathogens have therefore evolved strategies to subvert and/or manipulate TLR signaling. Both the impairment and uncontrolled activation of TLR signaling can harm the host, causing tissue destruction and allowing pathogens to proliferate, thus favoring disease progression. In this context, microbial proteases are key virulence factors that modify components of the TLR signaling pathway. In this review, we discuss the role of bacterial and viral proteases in the manipulation of TLR signaling, highlighting the importance of these enzymes during the development of infectious diseases.
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Affiliation(s)
- Izabela Ciaston
- Department of Microbiology Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Ewelina Dobosz
- Department of Microbiology Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Jan Potempa
- Department of Microbiology Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland; Department of Oral Health and Systemic Disease, University of Louisville School of Dentistry, University of Louisville, Louisville, KY, USA.
| | - Joanna Koziel
- Department of Microbiology Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
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9
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Muresan XM, Slabáková E, Procházková J, Drápela S, Fedr R, Pícková M, Vacek O, Víchová R, Suchánková T, Bouchal J, Kürfürstová D, Král M, Hulínová T, Sýkora RP, Študent V, Hejret V, van Weerden WM, Puhr M, Pustka V, Potěšil D, Zdráhal Z, Culig Z, Souček K. Toll-Like Receptor 3 Overexpression Induces Invasion of Prostate Cancer Cells, whereas Its Activation Triggers Apoptosis. THE AMERICAN JOURNAL OF PATHOLOGY 2022; 192:1321-1335. [PMID: 35750257 DOI: 10.1016/j.ajpath.2022.05.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 04/29/2022] [Accepted: 05/17/2022] [Indexed: 01/27/2023]
Abstract
Toll-like receptor 3 (TLR3) is an endosomal receptor expressed in several immune and epithelial cells. Recent studies have highlighted its expression also in solid tumors, including prostate cancer (PCa), and described its role mainly in the proinflammatory response and induction of apoptosis. It has been found up-regulated in some castration-resistant prostate cancers. However, the role of TLR3 in prostate cancer progression remains largely unknown. We have experimentally demonstrated that exogenous TLR3 activation in PCa cell lines leads to the significant induction of secretion of the cytokines IL-6, IL-8, and interferon-β, depending on the model and chemoresistance status. Transcriptomic analysis of TLR3-overexpressing cells revealed a functional program that is enriched for genes involved in the regulation of cell motility, migration, and tumor invasiveness. Increased motility, migration, and invasion in TLR3-overexpressing cell line were confirmed by several in vitro assays and using an orthotopic prostate xenograft model in vivo. Furthermore, TLR3-ligand induced apoptosis via cleavage of caspase-3/7 and poly (ADP-ribose) polymerase, predominantly in TLR3-overexpressing cells. We conclude that TLR3 may be involved in prostate cancer progression and metastasis; however, it might also represent an Achilles heel of PCa, which can be exploited for targeted therapy.
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Affiliation(s)
- Ximena M Muresan
- Department of Cytokinetics, Institute of Biophysics of Czech Academy of Sciences, Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital in Brno, Brno, Czech Republic
| | - Eva Slabáková
- Department of Cytokinetics, Institute of Biophysics of Czech Academy of Sciences, Brno, Czech Republic
| | - Jiřina Procházková
- Department of Cytokinetics, Institute of Biophysics of Czech Academy of Sciences, Brno, Czech Republic
| | - Stanislav Drápela
- Department of Cytokinetics, Institute of Biophysics of Czech Academy of Sciences, Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital in Brno, Brno, Czech Republic; Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Radek Fedr
- Department of Cytokinetics, Institute of Biophysics of Czech Academy of Sciences, Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital in Brno, Brno, Czech Republic
| | - Markéta Pícková
- Department of Cytokinetics, Institute of Biophysics of Czech Academy of Sciences, Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital in Brno, Brno, Czech Republic; Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Ondřej Vacek
- Department of Cytokinetics, Institute of Biophysics of Czech Academy of Sciences, Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital in Brno, Brno, Czech Republic; Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Ráchel Víchová
- Department of Cytokinetics, Institute of Biophysics of Czech Academy of Sciences, Brno, Czech Republic
| | - Tereza Suchánková
- Department of Cytokinetics, Institute of Biophysics of Czech Academy of Sciences, Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital in Brno, Brno, Czech Republic
| | - Jan Bouchal
- Department of Clinical and Molecular Pathology, Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University, Olomouc, Czech Republic
| | | | - Milan Král
- Department of Urology, University Hospital, Olomouc, Czech Republic
| | - Tereza Hulínová
- Department of Clinical and Molecular Pathology, Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University, Olomouc, Czech Republic; Department of Clinical and Molecular Pathology, University Hospital, Ostrava, Czech Republic
| | - Radek P Sýkora
- Department of Urology, University Hospital, Ostrava, Czech Republic
| | - Vladimír Študent
- Department of Urology, University Hospital, Olomouc, Czech Republic
| | - Václav Hejret
- Bioinformatics Core Facility Central European Institute of Technology, Masaryk University, Brno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Wytske M van Weerden
- Department of Urology, Erasmus MC Cancer Institute, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Martin Puhr
- Proteomics Core Facility Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Václav Pustka
- Department of Urology, Experimental Urology, Innsbruck Medical University, Innsbruck, Austria
| | - David Potěšil
- Department of Urology, Experimental Urology, Innsbruck Medical University, Innsbruck, Austria
| | - Zbyněk Zdráhal
- Department of Urology, Experimental Urology, Innsbruck Medical University, Innsbruck, Austria
| | - Zoran Culig
- International Clinical Research Center, St. Anne's University Hospital in Brno, Brno, Czech Republic; Proteomics Core Facility Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Karel Souček
- Department of Cytokinetics, Institute of Biophysics of Czech Academy of Sciences, Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital in Brno, Brno, Czech Republic; Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic.
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10
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Innate Immune Response to Dengue Virus: Toll-like Receptors and Antiviral Response. Viruses 2022; 14:v14050992. [PMID: 35632732 PMCID: PMC9147118 DOI: 10.3390/v14050992] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 03/31/2022] [Accepted: 04/04/2022] [Indexed: 02/06/2023] Open
Abstract
Dengue is a mosquito-borne viral disease caused by the dengue virus (DENV1-4). The clinical manifestations range from asymptomatic to life-threatening dengue hemorrhagic fever (DHF) and/or Dengue Shock Syndrome (DSS). Viral and host factors are related to the clinical outcome of dengue, although the disease pathogenesis remains uncertain. The innate antiviral response to DENV is implemented by a variety of immune cells and inflammatory mediators. Blood monocytes, dendritic cells (DCs) and tissue macrophages are the main target cells of DENV infection. These cells recognize pathogen-associated molecular patterns (PAMPs) through pattern recognition receptors (PRRs). Pathogen recognition is a critical step in eliciting the innate immune response. Toll-like receptors (TLRs) are responsible for the innate recognition of pathogens and represent an essential component of the innate and adaptive immune response. Ten different TLRs are described in humans, which are expressed in many different immune cells. The engagement of TLRs with viral PAMPs triggers downstream signaling pathways leading to the production of inflammatory cytokines, interferons (IFNs) and other molecules essential for the prevention of viral replication. Here, we summarize the crucial TLRs’ roles in the antiviral innate immune response to DENV and their association with viral pathogenesis.
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11
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Cysteine Peptidase Cathepsin X as a Therapeutic Target for Simultaneous TLR3/4-mediated Microglia Activation. Mol Neurobiol 2022; 59:2258-2276. [PMID: 35066760 PMCID: PMC9016010 DOI: 10.1007/s12035-021-02694-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 12/09/2021] [Indexed: 12/04/2022]
Abstract
Microglia are resident macrophages in the central nervous system that are involved in immune responses driven by Toll-like receptors (TLRs). Microglia-mediated inflammation can lead to central nervous system disorders, and more than one TLR might be involved in these pathological processes. The cysteine peptidase cathepsin X has been recognized as a pathogenic factor for inflammation-induced neurodegeneration. Here, we hypothesized that simultaneous TLR3 and TLR4 activation induces synergized microglia responses and that these phenotype changes affect cathepsin X expression and activity. Murine microglia BV2 cells and primary murine microglia were exposed to the TLR3 ligand polyinosinic-polycytidylic acid (poly(I:C)) and the TLR4 ligand lipopolysaccharide (LPS), individually and simultaneously. TLR3 and TLR4 co-activation resulted in increased inflammatory responses compared to individual TLR activation, where poly(I:C) and LPS induced distinct patterns of proinflammatory factors together with different patterns of cathepsin X expression and activity. TLR co-activation decreased intracellular cathepsin X activity and increased cathepsin X localization at the plasma membrane with concomitant increased extracellular cathepsin X protein levels and activity. Inhibition of cathepsin X in BV2 cells by AMS36, cathepsin X inhibitor, significantly reduced the poly(I:C)- and LPS-induced production of proinflammatory cytokines as well as apoptosis. Additionally, inhibiting the TLR3 and TLR4 common signaling pathway, PI3K, with LY294002 reduced the inflammatory responses of the poly(I:C)- and LPS-activated microglia and recovered cathepsin X activity. We here provide evidence that microglial cathepsin X strengthens microglia activation and leads to subsequent inflammation-induced neurodegeneration. As such, cathepsin X represents a therapeutic target for treating neurodegenerative diseases related to excess inflammation.
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12
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Dias ML, O'Connor KM, Dempsey EM, O'Halloran KD, McDonald FB. Targeting the Toll-like receptor pathway as a therapeutic strategy for neonatal infection. Am J Physiol Regul Integr Comp Physiol 2021; 321:R879-R902. [PMID: 34612068 DOI: 10.1152/ajpregu.00307.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Toll-like receptors (TLRs) are crucial transmembrane receptors that form part of the innate immune response. They play a role in the recognition of various microorganisms and their elimination from the host. TLRs have been proposed as vital immunomodulators in the regulation of multiple neonatal stressors that extend beyond infection such as oxidative stress and pain. The immune system is immature at birth and takes some time to become fully established. As such, babies are especially vulnerable to sepsis at this early stage of life. Findings suggest a gestational age-dependent increase in TLR expression. TLRs engage with accessory and adaptor proteins to facilitate recognition of pathogens and their activation of the receptor. TLRs are generally upregulated during infection and promote the transcription and release of proinflammatory cytokines. Several studies report that TLRs are epigenetically modulated by chromatin changes and promoter methylation upon bacterial infection that have long-term influences on immune responses. TLR activation is reported to modulate cardiorespiratory responses during infection and may play a key role in driving homeostatic instability observed during sepsis. Although complex, TLR signaling and downstream pathways are potential therapeutic targets in the treatment of neonatal diseases. By reviewing the expression and function of key Toll-like receptors, we aim to provide an important framework to understand the functional role of these receptors in response to stress and infection in premature infants.
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Affiliation(s)
- Maria L Dias
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Karen M O'Connor
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Eugene M Dempsey
- Irish Centre for Maternal and Child Health Research, University College Cork, Cork, Ireland.,Department of Pediatrics and Child Health, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Ken D O'Halloran
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland.,Irish Centre for Maternal and Child Health Research, University College Cork, Cork, Ireland
| | - Fiona B McDonald
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland.,Irish Centre for Maternal and Child Health Research, University College Cork, Cork, Ireland
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13
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New Insights into the Role of Cysteine Cathepsins in Neuroinflammation. Biomolecules 2021; 11:biom11121796. [PMID: 34944440 PMCID: PMC8698589 DOI: 10.3390/biom11121796] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 11/25/2021] [Accepted: 11/29/2021] [Indexed: 12/12/2022] Open
Abstract
Neuroinflammation, which is mediated by microglia and astrocytes, is associated with the progression of neurodegenerative diseases. Increasing evidence shows that activated microglia induce the expression and secretion of various lysosomal cathepsins, particularly during the early stage of neuroinflammation. This trigger signaling cascade that aggravate neurodegeneration. To date, most research on neuroinflammation has focused on the role of cysteine cathepsins, the largest cathepsin family. Cysteine cathepsins are primarily responsible for protein degradation in lysosomes; however, they also play a role in regulating a number of other important physiological and pathological processes. This review focuses on the functional roles of cysteine cathepsins in the central nervous system during neuroinflammation, with an emphasis on their roles in the polarization of microglia and neuroinflammation signaling, which in turn causes neuronal death and thus neurodegeneration.
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14
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Klammer MG, Dzaye O, Wallach T, Krüger C, Gaessler D, Buonfiglioli A, Derkow K, Kettenmann H, Brinkmann MM, Lehnardt S. UNC93B1 Is Widely Expressed in the Murine CNS and Is Required for Neuroinflammation and Neuronal Injury Induced by MicroRNA let-7b. Front Immunol 2021; 12:715774. [PMID: 34589086 PMCID: PMC8475950 DOI: 10.3389/fimmu.2021.715774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/19/2021] [Indexed: 12/12/2022] Open
Abstract
The chaperone protein Unc-93 homolog B1 (UNC93B1) regulates internalization, trafficking, and stabilization of nucleic acid-sensing Toll-like receptors (TLR) in peripheral immune cells. We sought to determine UNC93B1 expression and its functional relevance in inflammatory and injurious processes in the central nervous system (CNS). We found that UNC93B1 is expressed in various CNS cells including microglia, astrocytes, oligodendrocytes, and neurons, as assessed by PCR, immunocyto-/histochemistry, and flow cytometry. UNC93B1 expression in the murine brain increased during development. Exposure to the microRNA let-7b, a recently discovered endogenous TLR7 activator, but also to TLR3 and TLR4 agonists, led to increased UNC93B1 expression in microglia and neurons. Microglial activation by extracellular let-7b required functional UNC93B1, as assessed by TNF ELISA. Neuronal injury induced by extracellular let-7b was dependent on UNC93B1, as UNC93B1-deficient neurons were unaffected by the microRNA's neurotoxicity in vitro. Intrathecal application of let-7b triggered neurodegeneration in wild-type mice, whereas mice deficient for UNC93B1 were protected against injurious effects on neurons and axons. In summary, our data demonstrate broad UNC93B1 expression in the murine brain and establish this chaperone as a modulator of neuroinflammation and neuronal injury triggered by extracellular microRNA and subsequent induction of TLR signaling.
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Affiliation(s)
- Markus G Klammer
- Institute of Cell Biology and Neurobiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Department of Neurology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Omar Dzaye
- Department of Radiology and Neuroradiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Thomas Wallach
- Institute of Cell Biology and Neurobiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Christina Krüger
- Institute of Cell Biology and Neurobiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Dorothea Gaessler
- Institute of Cell Biology and Neurobiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Alice Buonfiglioli
- Institute of Cell Biology and Neurobiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Katja Derkow
- Institute of Cell Biology and Neurobiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Helmut Kettenmann
- Cellular Neuroscience, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Melanie M Brinkmann
- Viral Immune Modulation Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Institute of Genetics, Technische Universität Braunschweig, Braunschweig, Germany
| | - Seija Lehnardt
- Institute of Cell Biology and Neurobiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Department of Neurology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
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15
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Ni J, Zhao J, Zhang X, Reinheckel T, Turk V, Nakanishi H. Cathepsin H deficiency decreases hypoxia-ischemia-induced hippocampal atrophy in neonatal mice through attenuated TLR3/IFN-β signaling. J Neuroinflammation 2021; 18:176. [PMID: 34376208 PMCID: PMC8353845 DOI: 10.1186/s12974-021-02227-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 07/26/2021] [Indexed: 01/11/2023] Open
Abstract
Background Cathepsin H (CatH) is a lysosomal cysteine protease with a unique aminopeptidase activity. Its expression level is increased in activated immune cells including dendritic cells, macrophages, and microglia. We have previously reported that CatH deficiency impairs toll-like receptor 3 (TLR3)-mediated activation of interferon regulatory factor 3 (IRF3), and the subsequent secretion of interferon (IFN)-β from dendritic cells. Furthermore, there is increasing evidence that IFN-β secreted from microglia/macrophages has neuroprotective effects. These observations prompted further investigation into the effects of CatH deficiency on neuropathological changes. Methods In this study, neuropathological changes were examined using histochemical staining (both hematoxylin-eosin (H&E) and Nissl) of the hippocampus of wild-type (WT) and CatH-deficient (CatH−/−) mice after hypoxia-ischemia (HI). The density and the localization of CatH and TLR3 were examined by immunofluorescent staining. CatH processing in microglia was assayed by pulse-chase experiments, while immunoblotting was used to examine TLR3 expression and IRF3 activation in microglia/macrophages in the presence of poly(I:C). Microglial cell death was examined by fluorescence-activated cell sorting (FACS), and primary astrocyte proliferation in the presence of IFN-β was examined using scratch wound assay. Results WT mice displayed severe atrophy in association with neuronal death and moderate astrogliosis in the hippocampus following neonatal HI. Somewhat surprisingly, CatH−/− mice showed marked neuronal death without severe atrophy in the hippocampus following HI. Furthermore, there was notable microglia/macrophages cell death and strong astrogliosis in the hippocampus. The TLR3 and phosphorylated IRF3 expression level in the hippocampus or splenocytes (mainly splenic macrophages); from CatH−/− mice was lower than in WT mice. In vitro experiments demonstrated that recombinant IFN-β suppressed HI-induced microglial cell death and astrocyte proliferation. Conclusion These observations suggest that CatH plays a critical role in the proteolytic maturation and stabilization of TLR3, which is necessary for IFN-β production. Therefore, impaired TLR3/IFN-β signaling resulting from CatH deficiency may induce microglial cell death after activation and astrogliosis/glial scar formation in the hippocampus following HI injury, leading to suppression of hippocampal atrophy.
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Affiliation(s)
- Junjun Ni
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China. .,Department of Aging Science and Pharmacology, Faculty of Dental Science, Kyushu University, Fukuoka, 812-8582, Japan.
| | - Juan Zhao
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Xinwen Zhang
- Center of Implant Dentistry, School of Somatology, China Medical University, Shenyang, 110122, China
| | - Thomas Reinheckel
- Institute of Molecular Medicine and Cell Research, University of Freiburg, 79104, Freiburg, Germany
| | - Vito Turk
- Department of Biochemistry and Molecular and Structural Biology, J. Stefan Institute, Ljubljana, Slovenia
| | - Hiroshi Nakanishi
- Department of Pharmacology, Faculty of Pharmacy, Yasuda Women's University, Hiroshima, 731-0153, Japan.
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16
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de Oliveira Mann CC, Hornung V. Molecular mechanisms of nonself nucleic acid recognition by the innate immune system. Eur J Immunol 2021; 51:1897-1910. [PMID: 34138462 DOI: 10.1002/eji.202049116] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/13/2021] [Accepted: 06/15/2021] [Indexed: 12/24/2022]
Abstract
Nucleic acids (NAs) represent one of the most important classes of molecules recognized by the innate immune system. However, NAs are not limited to pathogens, but are also present within the host. As such, the immune system has evolved an elaborate set of pathogen recognition receptors (PRRs) that employ various strategies to recognize distinct types of NAs, while reliably distinguishing between self and nonself. The here-employed strategies encompass the positioning of NA-sensing PRRs in certain subcellular compartments that potentially come in contact with pathogens but not host NAs, the existence of counterregulatory measures that keep endogenous NAs below a certain threshold, and also the specific identification of certain nonself patterns. Here, we review recent advances in the molecular mechanisms of NA recognition by TLRs, RLRs, and the cGAS-STING axis. We highlight the differences in NA-PRR interfaces that confer specificity and selectivity toward an NA ligand, as well as the NA-dependent induced conformational changes required for signal transduction.
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Affiliation(s)
| | - Veit Hornung
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
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17
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Chen CY, Hung YF, Tsai CY, Shih YC, Chou TF, Lai MZ, Wang TF, Hsueh YP. Transcriptomic Analysis and C-Terminal Epitope Tagging Reveal Differential Processing and Signaling of Endogenous TLR3 and TLR7. Front Immunol 2021; 12:686060. [PMID: 34211474 PMCID: PMC8240634 DOI: 10.3389/fimmu.2021.686060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 06/01/2021] [Indexed: 01/02/2023] Open
Abstract
Toll-like receptor (TLR) signaling is critical for defense against pathogenic infection, as well as for modulating tissue development. Activation of different TLRs triggers common inflammatory responses such as cytokine induction. Here, we reveal differential impacts of TLR3 and TLR7 signaling on transcriptomic profiles in bone marrow-derived macrophages (BMDMs). Apart from self-regulation, TLR3, but not TLR7, induced expression of other TLRs, suggesting that TLR3 activation globally enhances innate immunity. Moreover, we observed diverse influences of TLR3 and TLR7 signaling on genes involved in methylation, caspase and autophagy pathways. We compared endogenous TLR3 and TLR7 by using CRISPR/Cas9 technology to knock in a dual Myc-HA tag at the 3’ ends of mouse Tlr3 and Tlr7. Using anti-HA antibodies to detect endogenous tagged TLR3 and TLR7, we found that both TLRs display differential tissue expression and posttranslational modifications. C-terminal tagging did not impair TLR3 activity. However, it disrupted the interaction between TLR7 and myeloid differentiation primary response 88 (MYD88), the Tir domain-containing adaptor of TLR7, which blocked its downstream signaling necessary to trigger cytokine and chemokine expression. Our study demonstrates different properties for TLR3 and TLR7, and also provides useful mouse models for further investigation of these two RNA-sensing TLRs.
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Affiliation(s)
- Chiung-Ya Chen
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Yun-Fen Hung
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Ching-Yen Tsai
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Yi-Chun Shih
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Ting-Fang Chou
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Ming-Zong Lai
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Ting-Fang Wang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Yi-Ping Hsueh
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
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18
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Mielcarska MB, Bossowska-Nowicka M, Toka FN. Cell Surface Expression of Endosomal Toll-Like Receptors-A Necessity or a Superfluous Duplication? Front Immunol 2021; 11:620972. [PMID: 33597952 PMCID: PMC7882679 DOI: 10.3389/fimmu.2020.620972] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Accepted: 12/11/2020] [Indexed: 12/28/2022] Open
Abstract
Timely and precise delivery of the endosomal Toll-like receptors (TLRs) to the ligand recognition site is a critical event in mounting an effective antimicrobial immune response, however, the same TLRs should maintain the delicate balance of avoiding recognition of self-nucleic acids. Such sensing is widely known to start from endosomal compartments, but recently enough evidence has accumulated supporting the idea that TLR-mediated signaling pathways originating in the cell membrane may be engaged in various cells due to differential expression and distribution of the endosomal TLRs. Therefore, the presence of endosomal TLRs on the cell surface could benefit the host responses in certain cell types and/or organs. Although not fully understood why, TLR3, TLR7, and TLR9 may occur both in the cell membrane and intracellularly, and it seems that activation of the immune response can be initiated concurrently from these two sites in the cell. Furthermore, various forms of endosomal TLRs may be transported to the cell membrane, indicating that this may be a normal process orchestrated by cysteine proteases-cathepsins. Among the endosomal TLRs, TLR3 belongs to the evolutionary distinct group and engages a different protein adapter in the signaling cascade. The differently glycosylated forms of TLR3 are transported by UNC93B1 to the cell membrane, unlike TLR7, TLR8, and TLR9. The aim of this review is to reconcile various views on the cell surface positioning of endosomal TLRs and add perspective to the implication of such receptor localization on their function, with special attention to TLR3. Cell membrane-localized TLR3, TLR7, and TLR9 may contribute to endosomal TLR-mediated inflammatory signaling pathways. Dissecting this signaling axis may serve to better understand mechanisms influencing endosomal TLR-mediated inflammation, thus determine whether it is a necessity for immune response or simply a circumstantial superfluous duplication, with other consequences on immune response.
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Affiliation(s)
- Matylda Barbara Mielcarska
- Division of Immunology, Institute of Veterinary Medicine, Department of Preclinical Sciences, Warsaw University of Life Sciences, Warsaw, Poland
| | - Magdalena Bossowska-Nowicka
- Division of Immunology, Institute of Veterinary Medicine, Department of Preclinical Sciences, Warsaw University of Life Sciences, Warsaw, Poland
| | - Felix Ngosa Toka
- Division of Immunology, Institute of Veterinary Medicine, Department of Preclinical Sciences, Warsaw University of Life Sciences, Warsaw, Poland.,Center for Integrative Mammalian Research, Department of Biomedical Sciences, Ross University School of Veterinary Medicine, Basseterre, Saint Kitts and Nevis
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19
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Nakashima A, Tomono S, Yamazaki T, Inui M, Morita N, Ichimonji I, Takagi H, Nagaoka F, Matsumoto M, Ito Y, Yanagishita T, Miyake K, Watanabe D, Akashi-Takamura S. Phospholipase A2 from bee venom increases poly(I:C)-induced activation in human keratinocytes. Int Immunol 2021; 32:371-383. [PMID: 31957789 DOI: 10.1093/intimm/dxaa005] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 01/15/2020] [Indexed: 12/11/2022] Open
Abstract
Bee venom (BV) induces skin inflammation, characterized by erythema, blisters, edemas, pain and itching. Although BV has been found to have an inhibitory effect on toll-like receptors (TLRs), we here show that BV enhances keratinocyte responses to polyinosinic-polycytidylic acid [poly(I:C)], a ligand for TLR3. Our results revealed that the enhanced TLR activity was primarily induced by secretory phospholipase A2 (sPLA2), a component of BV (BV-sPLA2). PLA2 mediates the hydrolysis of membrane phospholipids into lysophospholipids and free fatty acids. We demonstrated that BV-sPLA2 increased the intracellular uptake of poly(I:C), phosphorylation of the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs), and poly(I:C)-mediated interleukin 8 production in human keratinocytes. We further showed that the enzymatic activity of BV-sPLA2 was essential for the increased uptake of poly(I:C). These findings suggest that BV-sPLA2 may induce a modification of the cell membrane structure, leading to enhanced poly(I:C) uptake in keratinocytes. BV-sPLA2 might be able to promote wound healing by enhancing TLR3 responses.
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Affiliation(s)
- Akina Nakashima
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan.,Department of Dermatology, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan
| | - Susumu Tomono
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan
| | - Tatsuya Yamazaki
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan
| | - Masanori Inui
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan
| | - Naoko Morita
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan
| | - Isao Ichimonji
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan
| | - Hidekazu Takagi
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan
| | - Fumiaki Nagaoka
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan
| | - Misako Matsumoto
- Department of Vaccine Immunology, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan.,Nebuta Research Institute for Life Sciences, Aomori University, Kohbata, Aomori, Japan
| | - Yasuhiko Ito
- Department of Nephrology and Rheumatology, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan
| | - Takeshi Yanagishita
- Department of Dermatology, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan
| | - Kensuke Miyake
- Division of Innate Immunity, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Daisuke Watanabe
- Department of Dermatology, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan
| | - Sachiko Akashi-Takamura
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan
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20
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Szulc-Dąbrowska L, Bossowska-Nowicka M, Struzik J, Toka FN. Cathepsins in Bacteria-Macrophage Interaction: Defenders or Victims of Circumstance? Front Cell Infect Microbiol 2020; 10:601072. [PMID: 33344265 PMCID: PMC7746538 DOI: 10.3389/fcimb.2020.601072] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/05/2020] [Indexed: 02/06/2023] Open
Abstract
Macrophages are the first encounters of invading bacteria and are responsible for engulfing and digesting pathogens through phagocytosis leading to initiation of the innate inflammatory response. Intracellular digestion occurs through a close relationship between phagocytic/endocytic and lysosomal pathways, in which proteolytic enzymes, such as cathepsins, are involved. The presence of cathepsins in the endo-lysosomal compartment permits direct interaction with and killing of bacteria, and may contribute to processing of bacterial antigens for presentation, an event necessary for the induction of antibacterial adaptive immune response. Therefore, it is not surprising that bacteria can control the expression and proteolytic activity of cathepsins, including their inhibitors – cystatins, to favor their own intracellular survival in macrophages. In this review, we summarize recent developments in defining the role of cathepsins in bacteria-macrophage interaction and describe important strategies engaged by bacteria to manipulate cathepsin expression and activity in macrophages. Particularly, we focus on specific bacterial species due to their clinical relevance to humans and animal health, i.e., Mycobacterium, Mycoplasma, Staphylococcus, Streptococcus, Salmonella, Shigella, Francisella, Chlamydia, Listeria, Brucella, Helicobacter, Neisseria, and other genera.
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Affiliation(s)
- Lidia Szulc-Dąbrowska
- Division of Immunology, Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences-Szkoła Główna Gospodarstwa Wejskiego, Warsaw, Poland
| | - Magdalena Bossowska-Nowicka
- Division of Immunology, Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences-Szkoła Główna Gospodarstwa Wejskiego, Warsaw, Poland
| | - Justyna Struzik
- Division of Immunology, Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences-Szkoła Główna Gospodarstwa Wejskiego, Warsaw, Poland
| | - Felix N Toka
- Division of Immunology, Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences-Szkoła Główna Gospodarstwa Wejskiego, Warsaw, Poland.,Center for Integrative Mammalian Research, Ross University School of Veterinary Medicine, Basseterre, Saint Kitts and Nevis
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21
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Mielcarska MB, Gregorczyk-Zboroch KP, Szulc-Da̧browska L, Bossowska-Nowicka M, Wyżewski Z, Cymerys J, Chodkowski M, Kiełbik P, Godlewski MM, Gieryńska M, Toka FN. Participation of Endosomes in Toll-Like Receptor 3 Transportation Pathway in Murine Astrocytes. Front Cell Neurosci 2020; 14:544612. [PMID: 33281554 PMCID: PMC7705377 DOI: 10.3389/fncel.2020.544612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 10/26/2020] [Indexed: 12/25/2022] Open
Abstract
TLR3 provides immediate type I IFN response following entry of stimulatory PAMPs into the CNS, as it is in HSV infection. The receptor plays a vital role in astrocytes, contributing to rapid infection sensing and suppression of viral replication, precluding the spread of virus beyond neurons. The route of TLR3 mobilization culminating in the receptor activation remains unexplained. In this research, we investigated the involvement of various types of endosomes in the regulation of the TLR3 mobility in C8-D1A murine astrocyte cell line. TLR3 was transported rapidly to early EEA1-positive endosomes as well as LAMP1-lysosomes following stimulation with the poly(I:C). Later, TLR3 largely associated with late Rab7-positive endosomes. Twenty-four hours after stimulation, TLR3 co-localized with LAMP1 abundantly in lysosomes of astrocytes. TLR3 interacted with poly(I:C) intracellularly from 1 min to 8 h following cell stimulation. We detected TLR3 on the surface of astrocytes indicating constitutive expression, which increased after poly(I:C) stimulation. Our findings contribute to the understanding of cellular modulation of TLR3 trafficking. Detailed analysis of the TLR3 transportation pathway is an important component in disclosing the fate of the receptor in HSV-infected CNS and may help in the search for rationale therapeutics to control the replication of neuropathic viruses.
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Affiliation(s)
- Matylda B Mielcarska
- Division of Immunology, Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| | - Karolina P Gregorczyk-Zboroch
- Division of Immunology, Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| | - Lidia Szulc-Da̧browska
- Division of Immunology, Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| | - Magdalena Bossowska-Nowicka
- Division of Immunology, Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| | - Zbigniew Wyżewski
- Institute of Biological Sciences, Cardinal Stefan Wyszynski University in Warsaw, Warsaw, Poland
| | - Joanna Cymerys
- Division of Microbiology, Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| | - Marcin Chodkowski
- Division of Microbiology, Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| | - Paula Kiełbik
- Division of Physiology, Department of Physiological Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| | - Michał M Godlewski
- Division of Physiology, Department of Physiological Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| | - Małgorzata Gieryńska
- Division of Immunology, Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| | - Felix N Toka
- Division of Immunology, Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland.,Center for Integrative Mammalian Research, Department of Biomedical Sciences, Ross University School of Veterinary Medicine, Basseterre, Saint Kitts and Nevis
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22
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Ubiquitination of TLR3 by TRIM3 signals its ESCRT-mediated trafficking to the endolysosomes for innate antiviral response. Proc Natl Acad Sci U S A 2020; 117:23707-23716. [PMID: 32878999 DOI: 10.1073/pnas.2002472117] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Trafficking of toll-like receptor 3 (TLR3) from the endoplasmic reticulum (ER) to endolysosomes and its subsequent proteolytic cleavage are required for it to sense viral double-stranded RNA (dsRNA) and trigger antiviral response, yet the underlying mechanisms remain enigmatic. We show that the E3 ubiquitin ligase TRIM3 is mainly located in the Golgi apparatus and transported to the early endosomes upon stimulation with the dsRNA analog poly(I:C). TRIM3 mediates K63-linked polyubiquitination of TLR3 at K831, which is enhanced following poly(I:C) stimulation. The polyubiquitinated TLR3 is recognized and sorted by the ESCRT (endosomal sorting complex required for transport) complexes to endolysosomes. Deficiency of TRIM3 impairs TLR3 trafficking from the Golgi apparatus to endosomes and its subsequent activation. Trim3 -/- cells and mice express lower levels of antiviral genes and show lower levels of inflammatory response following poly(I:C) but not lipopolysaccharide (LPS) stimulation. These findings suggest that TRIM3-mediated polyubiquitination of TLR3 represents a feedback-positive regulatory mechanism for TLR3-mediated innate immune and inflammatory responses.
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23
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Zablocki-Thomas L, Menzies SA, Lehner PJ, Manel N, Benaroch P. A genome-wide CRISPR screen identifies regulation factors of the TLR3 signalling pathway. Innate Immun 2020; 26:459-472. [PMID: 32248720 PMCID: PMC7491238 DOI: 10.1177/1753425920915507] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
A subset of TLRs is specialised in the detection of incoming pathogens by sampling endosomes for nucleic acid contents. Among them, TLR3 senses the abnormal presence of double-stranded RNA in the endosomes and initiates a potent innate immune response via activation of NF-κB and IRF3. Nevertheless, mechanisms governing TLR3 regulation remain poorly defined. To identify new molecular players involved in the TLR3 pathway, we performed a genome-wide screen using CRISPR/Cas9 technology. We generated TLR3+ reporter cells carrying a NF-κB-responsive promoter that controls GFP expression. Cells were next transduced with a single-guide RNA (sgRNA) library, subjected to sequential rounds of stimulation with poly(I:C) and sorting of the GFP-negative cells. Enrichments in sgRNA estimated by deep sequencing identified genes required for TLR3-induced activation of NF-κB. Among the hits, five genes known to be critically involved in the TLR3 pathway, including TLR3 itself and the chaperone UNC93B1, were identified by the screen, thus validating our strategy. We further studied the top 40 hits and focused on the transcription factor aryl hydrocarbon receptor (AhR). Depletion of AhR had a dual effect on the TLR3 response, abrogating IL-8 production and enhancing IP-10 release. Moreover, in primary human macrophages exposed to poly(I:C), AhR activation enhanced IL-8 and diminished IP-10 release. Overall, these results reveal AhR plays a role in the TLR3 cellular innate immune response.
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Affiliation(s)
| | - Sam A Menzies
- Department of Medicine, Cambridge Institute for Medical Research, Cambridge Biomedical Campus, UK
| | - Paul J Lehner
- Department of Medicine, Cambridge Institute for Medical Research, Cambridge Biomedical Campus, UK
| | - Nicolas Manel
- Institut Curie, PSL Research University, INSERM U932, France
| | - Philippe Benaroch
- Institut Curie, PSL Research University, INSERM U932, France,Philippe Benaroch, Institut Curie, PSL Research University, INSERM U932, France. Nicolas Manel, Institut Curie, PSL Research University, INSERM U932, France.
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24
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RNA Signaling in Pulmonary Arterial Hypertension-A Double-Stranded Sword. Int J Mol Sci 2020; 21:ijms21093124. [PMID: 32354189 PMCID: PMC7247700 DOI: 10.3390/ijms21093124] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 04/26/2020] [Accepted: 04/27/2020] [Indexed: 12/17/2022] Open
Abstract
Recognition of and response to pathogens and tissue injury is driven by the innate immune system via activation of pattern recognition receptors. One of the many patterns recognized is RNA and, while several receptors bind RNA, Toll-like receptor 3 (TLR3) is well placed for initial recognition of RNA molecules due to its localization within the endosome. There is a growing body of work describing a role for TLR3 in maintenance of vascular homeostasis. For example, TLR3 deficiency has been shown to play repair and remodeling roles in the systemic vasculature and in lung parenchyma. A hallmark of pulmonary arterial hypertension (PAH) is pulmonary vascular remodeling, yet drivers and triggers of this remodeling remain incompletely understood. Based on its role in the systemic vasculature, our group discovered reduced endothelial TLR3 expression in PAH and revealed a protective role for a TLR3 agonist in rodent models of pulmonary hypertension. This review will provide an overview of RNA signaling in the vasculature and how it relates to PAH pathobiology, including whether targeting double-stranded RNA signaling is a potential treatment option for PAH.
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25
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Inshaw JRJ, Cutler AJ, Crouch DJM, Wicker LS, Todd JA. Genetic Variants Predisposing Most Strongly to Type 1 Diabetes Diagnosed Under Age 7 Years Lie Near Candidate Genes That Function in the Immune System and in Pancreatic β-Cells. Diabetes Care 2020; 43:169-177. [PMID: 31558544 PMCID: PMC6925581 DOI: 10.2337/dc19-0803] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 08/10/2019] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Immunohistological analyses of pancreata from patients with type 1 diabetes suggest distinct autoimmune islet β-cell pathology between those diagnosed at <7 years (<7 group) and those diagnosed at age ≥13 years (≥13 group), with both B- and T-lymphocyte islet inflammation common in children in the <7 group, whereas B cells are rare in the ≥13 group. Based on these observations, we sought to identify differences in genetic susceptibility between these prespecified age-at-diagnosis groups to inform on the etiology of the most aggressive form of type 1 diabetes that initiates in the first years of life. RESEARCH DESIGN AND METHODS Using multinomial logistic regression models, we tested if known type 1 diabetes loci (17 within the HLA and 55 non-HLA loci) had significantly stronger effect sizes in the <7 group compared with the ≥13 group, using genotype data from 27,071 individuals (18,485 control subjects and 3,121 case subjects diagnosed at <7 years, 3,757 at 7-13 years, and 1,708 at ≥13 years). RESULTS Six HLA haplotypes/classical alleles and six non-HLA regions, one of which functions specifically in β-cells (GLIS3) and the other five likely affecting key T-cell (IL2RA, IL10, IKZF3, and THEMIS), thymus (THEMIS), and B-cell development/functions (IKZF3 and IL10) or in both immune and β-cells (CTSH), showed evidence for stronger effects in the <7 group. CONCLUSIONS A subset of type 1 diabetes-associated variants are more prevalent in children diagnosed under the age of 7 years and are near candidate genes that act in both pancreatic β- and immune cells.
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Affiliation(s)
- Jamie R J Inshaw
- JDRF/Wellcome Diabetes and Inflammation Laboratory, Wellcome Centre for Human Genetics, University of Oxford, Oxford, U.K.
| | - Antony J Cutler
- JDRF/Wellcome Diabetes and Inflammation Laboratory, Wellcome Centre for Human Genetics, University of Oxford, Oxford, U.K
| | - Daniel J M Crouch
- JDRF/Wellcome Diabetes and Inflammation Laboratory, Wellcome Centre for Human Genetics, University of Oxford, Oxford, U.K
| | - Linda S Wicker
- JDRF/Wellcome Diabetes and Inflammation Laboratory, Wellcome Centre for Human Genetics, University of Oxford, Oxford, U.K
| | - John A Todd
- JDRF/Wellcome Diabetes and Inflammation Laboratory, Wellcome Centre for Human Genetics, University of Oxford, Oxford, U.K.
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26
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Zainol MIB, Kawasaki T, Monwan W, Murase M, Sueyoshi T, Kawai T. Innate immune responses through Toll-like receptor 3 require human-antigen-R-mediated Atp6v0d2 mRNA stabilization. Sci Rep 2019; 9:20406. [PMID: 31892731 PMCID: PMC6938500 DOI: 10.1038/s41598-019-56914-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 12/16/2019] [Indexed: 12/29/2022] Open
Abstract
Toll-like receptor 3 (TLR3) recognizes double-stranded RNA derived from virus and its synthetic analogue, polyinosinic–polycytidylic acid [poly(I:C)]. Upon poly(I:C) binding, TLR3 activates transcription factors to express inflammatory cytokines and type I interferon. TLR3 is located in the endosomes and its recognition of poly(I:C) and activation of downstream signaling is regulated by endosomal acidification. However, the mechanism of post-transcriptional regulation in TLR3-mediated innate responses remains unclear. Here, we focused on Human antigen R (HuR, also known as ELAVL1) that recognizes and binds to the 3′ untranslated regions (3′UTRs) of target mRNAs, thereby protecting them from mRNA degradation, and found that HuR-deficient murine macrophage cells showed significantly reduced Ifnb1 mRNA expression after poly(I:C) stimulation. HuR-deficient cells also showed a marked reduction in the expression of Atp6v0d2 mRNA, which encodes a subunit of vacuolar-type H+ ATPase (V-ATPase), and therefore reduced endosomal acidification. HuR associated with the 3′UTR of Atp6v0d2 mRNA and the stability of Atp6v0d2 mRNA was maintained by its association with HuR. Taken together, our results suggest that HuR stabilizes Atp6v0d2 mRNA, which is required for the TLR3-mediated innate immune responses.
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Affiliation(s)
- Mohd Izwan Bin Zainol
- Laboratory of Molecular Immunobiology, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Nara, 630-0192, Japan
| | - Takumi Kawasaki
- Laboratory of Molecular Immunobiology, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Nara, 630-0192, Japan.
| | - Warunthorn Monwan
- Laboratory of Molecular Immunobiology, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Nara, 630-0192, Japan
| | - Motoya Murase
- Laboratory of Molecular Immunobiology, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Nara, 630-0192, Japan
| | - Takuya Sueyoshi
- Laboratory of Molecular Immunobiology, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Nara, 630-0192, Japan
| | - Taro Kawai
- Laboratory of Molecular Immunobiology, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Nara, 630-0192, Japan.
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27
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HCMV-encoded US7 and US8 act as antagonists of innate immunity by distinctively targeting TLR-signaling pathways. Nat Commun 2019; 10:4670. [PMID: 31604943 PMCID: PMC6789044 DOI: 10.1038/s41467-019-12641-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 09/21/2019] [Indexed: 01/04/2023] Open
Abstract
The mechanisms by which many human cytomegalovirus (HCMV)-encoded proteins help the virus to evade immune surveillance remain poorly understood. In particular, it is unknown whether HCMV proteins arrest Toll-like receptor (TLR) signaling pathways required for antiviral defense. Here, we report that US7 and US8 as key suppressors that bind both TLR3 and TLR4, facilitating their destabilization by distinct mechanisms. US7 exploits the ER-associated degradation components Derlin-1 and Sec61, promoting ubiquitination of TLR3 and TLR4. US8 not only disrupts the TLR3-UNC93B1 association but also targets TLR4 to the lysosome, resulting in rapid degradation of the TLR. Accordingly, a mutant HCMV lacking the US7-US16 region has an impaired ability to hinder TLR3 and TLR4 activation, and the impairment is reversed by the introduction of US7 or US8. Our findings reveal an inhibitory effect of HCMV on TLR signaling, which contributes to persistent avoidance of the host antiviral response to achieve viral latency. Human cytomegalovirus (HCMV) has evolved several mechanisms to evade the host immune response. Here, Park et al. show that HCMV-encoded US7 and US8 proteins bind TLR3 and TLR4 and facilitate TLR degradation by distinct mechanisms, including ER-associated and lysosomal degradation.
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28
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Zhong X, Feng L, Xu WH, Wu X, Ding YD, Zhou Y, Lei CQ, Shu HB. The zinc-finger protein ZFYVE1 modulates TLR3-mediated signaling by facilitating TLR3 ligand binding. Cell Mol Immunol 2019; 17:741-752. [PMID: 31388100 DOI: 10.1038/s41423-019-0265-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 07/11/2019] [Indexed: 12/14/2022] Open
Abstract
Recognition of viral dsRNA by Toll-like receptor 3 (TLR3) leads to the induction of downstream antiviral effectors and the innate antiviral immune response. Here, we identified the zinc-finger FYVE domain-containing protein ZFYVE1, a guanylate-binding protein (GBP), as a positive regulator of TLR3-mediated signaling. Overexpression of ZFYVE1 promoted the transcription of downstream antiviral genes upon stimulation with the synthetic TLR3 ligand poly(I:C). Conversely, ZFYVE1 deficiency had the opposite effect. Zfyve1-/- mice were less susceptible than wild-type mice to inflammatory death induced by poly(I:C) but not LPS. ZFYVE1 was associated with TLR3, and the FYVE domain of ZFYVE1 and the ectodomain of TLR3 were shown to be responsible for their interaction. ZFYVE1 was bound to poly(I:C) and increased the binding affinity of TLR3 to poly(I:C). These findings suggest that ZFYVE1 plays an important role in the TLR3-mediated innate immune and inflammatory responses by promoting the ligand binding of TLR3.
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Affiliation(s)
- Xuan Zhong
- College of Life Sciences, Wuhan University, Wuhan, 430072, China.,Department of Infectious Diseases, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430072, China.,Medical Research Institute, Wuhan University, Wuhan, 430072, China
| | - Lu Feng
- College of Life Sciences, Wuhan University, Wuhan, 430072, China.,Department of Infectious Diseases, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430072, China.,Medical Research Institute, Wuhan University, Wuhan, 430072, China
| | - Wen-Hua Xu
- College of Life Sciences, Wuhan University, Wuhan, 430072, China.,Department of Infectious Diseases, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430072, China.,Medical Research Institute, Wuhan University, Wuhan, 430072, China
| | - Xin Wu
- College of Life Sciences, Wuhan University, Wuhan, 430072, China.,Department of Infectious Diseases, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430072, China.,Medical Research Institute, Wuhan University, Wuhan, 430072, China
| | - Yi-Di Ding
- College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Yan Zhou
- College of Life Sciences, Wuhan University, Wuhan, 430072, China.,Department of Infectious Diseases, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430072, China.,Medical Research Institute, Wuhan University, Wuhan, 430072, China
| | - Cao-Qi Lei
- College of Life Sciences, Wuhan University, Wuhan, 430072, China. .,Department of Infectious Diseases, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430072, China. .,Medical Research Institute, Wuhan University, Wuhan, 430072, China.
| | - Hong-Bing Shu
- College of Life Sciences, Wuhan University, Wuhan, 430072, China. .,Department of Infectious Diseases, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430072, China. .,Medical Research Institute, Wuhan University, Wuhan, 430072, China.
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29
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Gruber E, Heyward C, Cameron J, Leifer C. Toll-like receptor signaling in macrophages is regulated by extracellular substrate stiffness and Rho-associated coiled-coil kinase (ROCK1/2). Int Immunol 2019; 30:267-278. [PMID: 29800294 DOI: 10.1093/intimm/dxy027] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 04/04/2018] [Indexed: 02/07/2023] Open
Abstract
Macrophages participate in immunity, tissue repair and tissue homeostasis. Activation of Toll-like receptors (TLRs) by conserved exogenous or endogenous structures initiates signaling cascades that result in the release of cytokines such as tumor necrosis factor α (TNFα). Extracellular substrate stiffness is known to regulate functions of non-immune cells through a process called mechanotransduction, yet less is known about how physical cues affect macrophage function or TLR signaling. To investigate this question, we cultured murine primary bone marrow-derived macrophages (BMMs) and RAW264.7 cells on fibronectin-coated polyacrylamide (PA) gels of defined stiffnesses (1, 20 and 150 kPa) that approximate the physical properties of physiologic tissues. BMMs on all gels were smaller and more circular than those on rigid glass. Macrophages on intermediate stiffness 20 kPa PA gels were slightly larger and less circular than those on either 1 or 150 kPa. Secretion of the pro-inflammatory cytokine, TNFα, in response to stimulation of TLR4 and TLR9 was increased in macrophages grown on soft gels versus more rigid gels, particularly for BMMs. Inhibition of the rho-associated coiled-coil kinase 1/2 (ROCK1/2), key mediators in cell contractility and mechanotransduction, enhanced release of TNFα in response to stimulation of TLR4. ROCK1/2 inhibition enhanced phosphorylation of the TLR downstream signaling molecules, p38, ERK1/2 and NFκB. Our data indicate that physical cues from the extracellular environment regulate macrophage morphology and TLR signaling. These findings have important implications in the regulation of macrophage function in diseased tissues and offer a novel pharmacological target for the manipulation of macrophage function in vivo.
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Affiliation(s)
- Erika Gruber
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Christa Heyward
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Jody Cameron
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Cynthia Leifer
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
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30
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Syk and Hrs Regulate TLR3-Mediated Antiviral Response in Murine Astrocytes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:6927380. [PMID: 31089414 PMCID: PMC6476135 DOI: 10.1155/2019/6927380] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 12/22/2018] [Accepted: 01/13/2019] [Indexed: 12/02/2022]
Abstract
Toll-like receptors (TLRs) sense the presence of pathogen-associated molecular patterns. Nevertheless, the mechanisms modulating TLR-triggered innate immune responses are not yet fully understood. Complex regulatory systems exist to appropriately direct immune responses against foreign or self-nucleic acids, and a critical role of hepatocyte growth factor-regulated tyrosine kinase substrate (HRS), endosomal sorting complex required for transportation-0 (ESCRT-0) subunit, has recently been implicated in the endolysosomal transportation of TLR7 and TLR9. We investigated the involvement of Syk, Hrs, and STAM in the regulation of the TLR3 signaling pathway in a murine astrocyte cell line C8-D1A following cell stimulation with a viral dsRNA mimetic. Our data uncover a relationship between TLR3 and ESCRT-0, point out Syk as dsRNA-activated kinase, and suggest the role for Syk in mediating TLR3 signaling in murine astrocytes. We show molecular events that occur shortly after dsRNA stimulation of astrocytes and result in Syk Tyr-342 phosphorylation. Further, TLR3 undergoes proteolytic processing; the resulting TLR3 N-terminal form interacts with Hrs. The knockdown of Syk and Hrs enhances TLR3-mediated antiviral response in the form of IFN-β, IL-6, and CXCL8 secretion. Understanding the role of Syk and Hrs in TLR3 immune responses is of high importance since activation and precise execution of the TLR3 signaling pathway in the brain seem to be particularly significant in mounting an effective antiviral defense. Infection of the brain with herpes simplex type 1 virus may increase the secretion of amyloid-β by neurons and astrocytes and be a causal factor in degenerative diseases such as Alzheimer's disease. Errors in TLR3 signaling, especially related to the precise regulation of the receptor transportation and degradation, need careful observation as they may disclose foundations to identify novel or sustain known therapeutic targets.
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31
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Vierbuchen T, Stein K, Heine H. RNA is taking its Toll: Impact of RNA-specific Toll-like receptors on health and disease. Allergy 2019; 74:223-235. [PMID: 30475385 DOI: 10.1111/all.13680] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 11/08/2018] [Accepted: 11/20/2018] [Indexed: 12/13/2022]
Abstract
RNA-sensing Toll-like receptors (TLRs) are often described as antiviral receptors of the innate immune system. However, the past decade has shown that the function and relevance of these receptors are far more complex. They were found to be essential for the detection of various bacterial, archaeal, and eukaryotic microorganisms and facilitate the discrimination between dead and living microbes. The cytokine and interferon response profile that is triggered has the potential to improve the efficacy of next-generation vaccines and may prevent the development of asthma and allergy. Nevertheless, the ability to recognize foreign RNA comes with a cost as also damaged host cells can release nucleic acids that might induce an inappropriate immune response. Thus, it is not surprising that RNA-sensing TLRs play a key role in various autoimmune diseases. However, promising new inhibitors and antagonists are on the horizon to improve their treatment.
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Affiliation(s)
- Tim Vierbuchen
- Division of Innate Immunity Research Center Borstel – Leibniz Lung Center Borstel Germany
| | - Karina Stein
- Division of Innate Immunity Research Center Borstel – Leibniz Lung Center Borstel Germany
- Airway Research Center North (ARCN) German Center for Lung Research (DZL) Borstel Germany
| | - Holger Heine
- Division of Innate Immunity Research Center Borstel – Leibniz Lung Center Borstel Germany
- Airway Research Center North (ARCN) German Center for Lung Research (DZL) Borstel Germany
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Pelka K, Bertheloot D, Reimer E, Phulphagar K, Schmidt SV, Christ A, Stahl R, Watson N, Miyake K, Hacohen N, Haas A, Brinkmann MM, Marshak-Rothstein A, Meissner F, Latz E. The Chaperone UNC93B1 Regulates Toll-like Receptor Stability Independently of Endosomal TLR Transport. Immunity 2019; 48:911-922.e7. [PMID: 29768176 DOI: 10.1016/j.immuni.2018.04.011] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Revised: 02/21/2018] [Accepted: 04/10/2018] [Indexed: 01/11/2023]
Abstract
Unc-93 homolog B1 (UNC93B1) is a key regulator of nucleic acid (NA)-sensing Toll-like receptors (TLRs). Loss of NA-sensing TLR responses in UNC93B1-deficient patients facilitates Herpes simplex virus type 1 (HSV-1) encephalitis. UNC93B1 is thought to guide NA-sensing TLRs from the endoplasmic reticulum (ER) to their respective endosomal signaling compartments and to guide the flagellin receptor TLR5 to the cell surface, raising the question of how UNC93B1 mediates differential TLR trafficking. Here, we report that UNC93B1 regulates a step upstream of the differential TLR trafficking process. We discovered that UNC93B1 deficiency resulted in near-complete loss of TLR3 and TLR7 proteins in primary splenic mouse dendritic cells and macrophages, showing that UNC93B1 is critical for maintaining TLR expression. Notably, expression of an ER-retained UNC93B1 version was sufficient to stabilize TLRs and largely restore endosomal TLR trafficking and activity. These data are critical for an understanding of how UNC93B1 can regulate the function of a broad subset of TLRs.
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Affiliation(s)
- Karin Pelka
- Institute of Innate Immunity, University Hospital Bonn, 53127 Bonn, Germany; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Damien Bertheloot
- Institute of Innate Immunity, University Hospital Bonn, 53127 Bonn, Germany; IFM Therapeutics GmbH, 53127 Bonn, Germany
| | - Elisa Reimer
- Viral Immune Modulation Research Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Kshiti Phulphagar
- Institute of Innate Immunity, University Hospital Bonn, 53127 Bonn, Germany; Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Susanne V Schmidt
- Institute of Innate Immunity, University Hospital Bonn, 53127 Bonn, Germany
| | - Anette Christ
- Institute of Innate Immunity, University Hospital Bonn, 53127 Bonn, Germany; Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Rainer Stahl
- Institute of Innate Immunity, University Hospital Bonn, 53127 Bonn, Germany
| | - Nicki Watson
- W.M. Keck Microscopy Facility, the Whitehead Institute, Cambridge, MA 02142, USA
| | - Kensuke Miyake
- Division of Innate Immunity, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo 108 8639, Japan; Laboratory of Innate Immunity, Center for Experimental Medicine and Systems Biology, Institute of Medical Science, University of Tokyo, Tokyo 108 8639, Japan
| | - Nir Hacohen
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Cancer Research, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Albert Haas
- Cell Biology Institute, University of Bonn, 53121 Bonn, Germany
| | - Melanie M Brinkmann
- Viral Immune Modulation Research Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Ann Marshak-Rothstein
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Felix Meissner
- Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Eicke Latz
- Institute of Innate Immunity, University Hospital Bonn, 53127 Bonn, Germany; Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA; German Center for Neurodegenerative Diseases, 53175 Bonn, Germany.
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Tatematsu M, Funami K, Seya T, Matsumoto M. Extracellular RNA Sensing by Pattern Recognition Receptors. J Innate Immun 2018; 10:398-406. [PMID: 30404092 PMCID: PMC6784046 DOI: 10.1159/000494034] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 09/25/2018] [Accepted: 09/25/2018] [Indexed: 12/11/2022] Open
Abstract
RNA works as a genome and messenger in RNA viruses, and it sends messages in most of the creatures of the Earth, including viruses, bacteria, fungi, plants, and animals. The human innate immune system has evolved to detect single- and double-stranded RNA molecules from microbes by pattern recognition receptors and induce defense reactions against infections such as the production of type I interferons and inflammatory cytokines. To avoid cytokine toxicity causing chronic inflammation or autoimmunity by sensing self-RNA, the activation of RNA sensors is strictly regulated. All of the Toll-like receptors that recognize RNA are localized to endosomes/lysosomes, which require internalization of RNA for sensing through an endocytic pathway. RIG-I-like receptors sense RNA in cytosol. These receptors are expressed in a cell type-specific fashion, enabling sensing of RNA for a wide range of microbial invasions. At the same time, both endosomal and cytoplasmic receptors have strategies to respond only to RNA of pathogenic microorganisms or dying cells. RNA are potential vaccine adjuvants for immune enhancement against cancer and provide a benefit for vaccinations. Understanding the detailed molecular mechanisms of the RNA-sensing system will help us to broaden the clinical utility of RNA adjuvants for patients with incurable diseases.
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Affiliation(s)
- Megumi Tatematsu
- Department of Vaccine Immunology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
- Dr. von Hauner Children's Hospital, Department of Pediatrics, University Hospital, LMU Munich, Munich, Germany
| | - Kenji Funami
- Department of Vaccine Immunology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Tsukasa Seya
- Department of Vaccine Immunology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Misako Matsumoto
- Department of Vaccine Immunology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
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Zhao J, Xue Y, Pan Y, Yao A, Wang G, Li D, Wang T, Zhao S, Hou Y. Toll-like receptor 3 agonist poly I:C reinforces the potency of cytotoxic chemotherapy via the TLR3-UNC93B1-IFN-β signaling axis in paclitaxel-resistant colon cancer. J Cell Physiol 2018; 234:7051-7061. [PMID: 30387134 DOI: 10.1002/jcp.27459] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Accepted: 08/29/2018] [Indexed: 12/19/2022]
Abstract
Type I interferon (IFN) signaling in neoplastic cells has a chemo-sensitizing effect in cancer therapy. Toll-like receptor 3 (TLR3) activation promotes IFN-β production, which induces apoptosis and impairs proliferation in some cancer cells. Herein, we tested whether the TLR3 agonist polyinosinic: polycytidylic acid (poly I:C) can improve chemotherapeutic efficacy in paclitaxel (PTX) resistant cell lines. Human colon cancer cell lines HCT116, SW620, HCT-8 (sensitive to PTX), and HCT-8/PTX (resistant to PTX) were treated with poly I:C and the cell viability was measured. Results showed that poly I:C specifically impaired the cell viability of HCT-8/PTX by simultaneously promoting cell apoptosis and inhibiting cell proliferation. In addition, when TLR3 was overexpressed in HCT-8/PTX cells, we found that TLR3 contributed to the production of IFN-β that reduced cell viability, and poly I:C preferentially activated the TLR3-UNC93B1 signaling pathway to mediate this effect. Moreover, cotreatment of poly I:C and PTX acted synergistically to induce cell apoptosis of HCT-8/PTX via upregulating the expression of TLR3 and its molecular chaperone UNC93B1, assisting in the secretion of IFN-β. Notably, a combination of poly I:C and PTX synergistically inhibited the PTX-resistant tumor growth in vivo without side effects. In conclusion, our studies demonstrate that poly I:C reinforces the potency of cytotoxic chemotherapeutics in PTX-resistant cell line through the TLR3-UNC93B1-IFN-β signaling pathway, which supplies a novel mechanism of poly I:C for the chemotherapy sensitizing effect in a PTX-resistant tumor.
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Affiliation(s)
- Jiaojiao Zhao
- Division of Immunology, The State Key Laboratory of Pharmaceutical Biotechnology, Medical School, Nanjing University, Nanjing, China
| | - Yaxian Xue
- Division of Immunology, The State Key Laboratory of Pharmaceutical Biotechnology, Medical School, Nanjing University, Nanjing, China
| | - Yuchen Pan
- Division of Immunology, The State Key Laboratory of Pharmaceutical Biotechnology, Medical School, Nanjing University, Nanjing, China
| | - Anran Yao
- Division of Immunology, The State Key Laboratory of Pharmaceutical Biotechnology, Medical School, Nanjing University, Nanjing, China
| | - Guoqun Wang
- Department of Oncology, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Dan Li
- Division of Immunology, The State Key Laboratory of Pharmaceutical Biotechnology, Medical School, Nanjing University, Nanjing, China
| | - Tingting Wang
- Division of Immunology, The State Key Laboratory of Pharmaceutical Biotechnology, Medical School, Nanjing University, Nanjing, China
| | - Shuli Zhao
- General Clinical Research Center, Nanjing First hospital, Nanjing Medical University, Nanjing, China
| | - Yayi Hou
- Division of Immunology, The State Key Laboratory of Pharmaceutical Biotechnology, Medical School, Nanjing University, Nanjing, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, China
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Abstract
Toll-like receptor 5 (TLR5) of mammals, birds, and reptiles detects bacterial flagellin and signals as a homodimeric complex. Structural studies using truncated TLR5b of zebrafish confirm the homodimeric TLR5-flagellin interaction. Here we provide evidence that zebrafish (Danio rerio) TLR5 unexpectedly signals as a heterodimer composed of the duplicated gene products drTLR5b and drTLR5a. Flagellin-induced signaling by the zebrafish TLR5 heterodimer increased in the presence of the TLR trafficking chaperone UNC93B1. Targeted exchange of drTLR5b and drTLR5a regions revealed that TLR5 activation needs a heterodimeric configuration of the receptor ectodomain and cytoplasmic domain, consistent with ligand-induced changes in receptor conformation. Structure-guided substitution of the presumed principal flagellin-binding site in human TLR5 with corresponding zebrafish TLR5 residues abrogated human TLR5 activation, indicating a species-specific TLR5-flagellin interaction. Our findings indicate that the duplicated TLR5 of zebrafish underwent subfunctionalization through concerted coevolution to form a unique heterodimeric flagellin receptor that operates fundamentally differently from TLR5 of other species.
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Lee SMY, Yip TF, Yan S, Jin DY, Wei HL, Guo RT, Peiris JSM. Recognition of Double-Stranded RNA and Regulation of Interferon Pathway by Toll-Like Receptor 10. Front Immunol 2018; 9:516. [PMID: 29616030 PMCID: PMC5865411 DOI: 10.3389/fimmu.2018.00516] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 02/27/2018] [Indexed: 12/16/2022] Open
Abstract
Toll-like receptor (TLR)-10 remains an orphan receptor without well-characterized ligands or functions. Here, we reveal that TLR10 is predominantly localized to endosomes and binds dsRNA in vitro at endosomal pH, suggesting that dsRNA is a ligand of TLR10. Recognition of dsRNA by TLR10 activates recruitment of myeloid differentiation primary response gene 88 for signal transduction and suppression of interferon regulatory factor-7 dependent type I IFN production. We also demonstrate crosstalk between TLR10 and TLR3, as they compete with each other for dsRNA binding. Our results suggest for the first time that dsRNA is a ligand for TLR10 and propose novel dual functions of TLR10 in regulating IFN signaling: first, recognition of dsRNA as a nucleotide-sensing receptor and second, sequestration of dsRNA from TLR3 to inhibit TLR3 signaling in response to dsRNA stimulation.
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Affiliation(s)
- Suki Man-Yan Lee
- HKU-Pasteur Research Pole and Center of Influenza Research, Li Ka Shing Faculty of Medicine, School of Public Health, The University of Hong Kong, Pokfulam, Hong Kong
| | - Tsz-Fung Yip
- HKU-Pasteur Research Pole and Center of Influenza Research, Li Ka Shing Faculty of Medicine, School of Public Health, The University of Hong Kong, Pokfulam, Hong Kong
| | - Sheng Yan
- HKU-Pasteur Research Pole and Center of Influenza Research, Li Ka Shing Faculty of Medicine, School of Public Health, The University of Hong Kong, Pokfulam, Hong Kong
| | - Dong-Yan Jin
- Li Ka Shing Faculty of Medicine, School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Hong-Li Wei
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Rey-Ting Guo
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Joseph Sriyal Malik Peiris
- HKU-Pasteur Research Pole and Center of Influenza Research, Li Ka Shing Faculty of Medicine, School of Public Health, The University of Hong Kong, Pokfulam, Hong Kong
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Duffney PF, McCarthy CE, Nogales A, Thatcher TH, Martinez-Sobrido L, Phipps RP, Sime PJ. Cigarette smoke dampens antiviral signaling in small airway epithelial cells by disrupting TLR3 cleavage. Am J Physiol Lung Cell Mol Physiol 2018; 314:L505-L513. [PMID: 29351447 PMCID: PMC5900359 DOI: 10.1152/ajplung.00406.2017] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 12/08/2017] [Accepted: 12/08/2017] [Indexed: 12/20/2022] Open
Abstract
Cigarette smokers and people exposed to second-hand smoke are at an increased risk for pulmonary viral infections, and yet the mechanism responsible for this heightened susceptibility is not understood. To understand the effect of cigarette smoke on susceptibility to viral infection, we used an air-liquid interface culture system and exposed primary human small airway epithelial cells (SAEC) to whole cigarette smoke, followed by treatment with the viral mimetic polyinosinic polycytidylic acid (poly I:C) or influenza A virus (IAV). We found that prior smoke exposure strongly inhibited production of proinflammatory (interleukin-6 and interleukin-8) and antiviral [interferon-γ-induced protein 10 (IP-10) and interferons] mediators in SAECs in response to poly I:C and IAV infection. Impaired antiviral responses corresponded to increased infection with IAV. This was associated with a decrease in phosphorylation of the key antiviral transcription factor interferon response factor 3 (IRF3). Here, we found that cigarette smoke exposure inhibited activation of Toll-like receptor 3 (TLR3) by impairing TLR3 cleavage, which was required for downstream phosphorylation of IRF3 and production of IP-10. These results identify a novel mechanism by which cigarette smoke exposure impairs antiviral responses in lung epithelial cells, which may contribute to increased susceptibility to respiratory infections.
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Affiliation(s)
- Parker F Duffney
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry , Rochester, New York
| | - Claire E McCarthy
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry , Rochester, New York
| | - Aitor Nogales
- Department of Microbiology and Immunology, University of Rochester , Rochester, New York
| | - Thomas H Thatcher
- Lung Biology and Disease Program, University of Rochester School of Medicine and Dentistry , Rochester, New York
- Division of Pulmonary and Critical Care Medicine, University of Rochester School of Medicine and Dentistry , Rochester, New York
| | - Luis Martinez-Sobrido
- Department of Microbiology and Immunology, University of Rochester , Rochester, New York
| | - Richard P Phipps
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry , Rochester, New York
- Department of Microbiology and Immunology, University of Rochester , Rochester, New York
- Lung Biology and Disease Program, University of Rochester School of Medicine and Dentistry , Rochester, New York
- Division of Pulmonary and Critical Care Medicine, University of Rochester School of Medicine and Dentistry , Rochester, New York
| | - Patricia J Sime
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry , Rochester, New York
- Department of Microbiology and Immunology, University of Rochester , Rochester, New York
- Lung Biology and Disease Program, University of Rochester School of Medicine and Dentistry , Rochester, New York
- Division of Pulmonary and Critical Care Medicine, University of Rochester School of Medicine and Dentistry , Rochester, New York
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38
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Mielcarska MB, Bossowska-Nowicka M, Toka FN. Functional failure of TLR3 and its signaling components contribute to herpes simplex encephalitis. J Neuroimmunol 2017; 316:65-73. [PMID: 29305044 DOI: 10.1016/j.jneuroim.2017.12.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 12/17/2017] [Accepted: 12/17/2017] [Indexed: 02/06/2023]
Abstract
Herpes simplex encephalitis (HSE) is a severe neurological disease in children and adults caused by herpes simplex virus. This review discusses recent findings on the role of Toll-like receptor 3 (TLR3) deficiencies in the HSE development. Critical checkpoints in the TLR3 signaling that contribute to innate response are discussed, including the importance of TLR3 ligand recognition site and transportation in the cell. We also indicate unresolved issues in the TLR3 functioning that might lead to thorough understanding of immunity during HSE. Such a knowledge base will lead to discovery and design of a rationale therapeutic and preventive approach against HSE.
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Affiliation(s)
- Matylda Barbara Mielcarska
- Division of Immunology, Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Ciszewskiego 8 Str., 02-786 Warsaw, Poland.
| | - Magdalena Bossowska-Nowicka
- Division of Immunology, Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Ciszewskiego 8 Str., 02-786 Warsaw, Poland
| | - Felix Ngosa Toka
- Division of Immunology, Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Ciszewskiego 8 Str., 02-786 Warsaw, Poland; Center for Integrative Mammalian Research, Ross University School of Veterinary Medicine, PO Box 334, Basseterre, Saint Kitts and Nevis
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39
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Shimizu T. Structural insights into ligand recognition and regulation of nucleic acid-sensing Toll-like receptors. Curr Opin Struct Biol 2017; 47:52-59. [DOI: 10.1016/j.sbi.2017.05.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 05/14/2017] [Accepted: 05/22/2017] [Indexed: 01/06/2023]
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40
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Saha SS, Caviness G, Yi G, Raymond EL, Mbow ML, Kao CC. E3 Ubiquitin Ligase RNF125 Activates Interleukin-36 Receptor Signaling and Contributes to Its Turnover. J Innate Immun 2017; 10:56-69. [PMID: 29176319 DOI: 10.1159/000481210] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 09/04/2017] [Indexed: 12/14/2022] Open
Abstract
Signaling by the interleukin-36 receptor (IL-36R) is linked to inflammatory diseases such as psoriasis. However, the regulation of IL-36R signaling is poorly understood. Activation of IL-36R signaling in cultured cells results in an increased polyubiquitination of the receptor subunit, IL-1Rrp2. Treatment with deubiquitinases shows that the receptor subunit of IL-36R, IL-1Rrp2, is primarily polyubiquitinated at the K63 position, which is associated with endocytic trafficking and signal transduction. A minor amount of ubiquitination is at the K48 position that is associated with protein degradation. A focused siRNA screen identified RNF125, an E3 ubiquitin ligase, to ubiquitinate IL-1Rrp2 upon activation of IL-36R signaling while not affecting the activated IL-1 receptor. Knockdown of RNF125 decreases signal transduction by the IL-36R. Overexpression of RNF125 in HEK293T cells activates IL-36R signaling and increases the ubiquitination of IL-1Rrp2 and its subsequent turnover. RNF125 can coimmunoprecipitate with the IL-36R, and it traffics with IL-1Rrp2 from the cell surface to lysosomes. Mutations of Lys568 and Lys569 in the C-terminal tail of IL-1Rrp2 decrease ubiquitination by RNF125 and increase the steady-state levels of IL-1Rrp2. These results demonstrate that RNF125 has multiple regulatory roles in the signaling, trafficking, and turnover of the IL-36R.
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Affiliation(s)
- Siddhartha S Saha
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, USA
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41
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Sun L, Jiang Z, Acosta-Rodriguez VA, Berger M, Du X, Choi JH, Wang J, Wang KW, Kilaru GK, Mohawk JA, Quan J, Scott L, Hildebrand S, Li X, Tang M, Zhan X, Murray AR, La Vine D, Moresco EMY, Takahashi JS, Beutler B. HCFC2 is needed for IRF1- and IRF2-dependent Tlr3 transcription and for survival during viral infections. J Exp Med 2017; 214:3263-3277. [PMID: 28970238 PMCID: PMC5679162 DOI: 10.1084/jem.20161630] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 07/13/2017] [Accepted: 08/16/2017] [Indexed: 01/08/2023] Open
Abstract
Sun et al. show that host cell factor C2 (HCFC2) is necessary for basal and induced Tlr3 transcription; deficiency of HCFC2 compromises survival during influenza virus and herpes simplex virus 1 infections in mice. Transcriptional regulation of numerous interferon-regulated genes, including Toll-like receptor 3 (Tlr3), which encodes an innate immune sensor of viral double-stranded RNA, depends on the interferon regulatory factor 1 (IRF1) and IRF2 transcription factors. We detected specific abrogation of macrophage responses to polyinosinic-polycytidylic acid (poly(I:C)) resulting from three independent N-ethyl-N-nitrosourea–induced mutations in host cell factor C2 (Hcfc2). Hcfc2 mutations compromised survival during influenza virus and herpes simplex virus 1 infections. HCFC2 promoted the binding of IRF1 and IRF2 to the Tlr3 promoter, without which inflammatory cytokine and type I IFN responses to the double-stranded RNA analogue poly(I:C) are reduced in mouse macrophages. HCFC2 was also necessary for the transcription of a large subset of other IRF2-dependent interferon-regulated genes. Deleterious mutations of Hcfc2 may therefore increase susceptibility to diverse infectious diseases.
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Affiliation(s)
- Lei Sun
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX
| | - Zhengfan Jiang
- Department of Genetics, The Scripps Research Institute, La Jolla, CA
| | - Victoria A Acosta-Rodriguez
- Department of Neuroscience, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX
| | - Michael Berger
- Department of Genetics, The Scripps Research Institute, La Jolla, CA
| | - Xin Du
- Department of Genetics, The Scripps Research Institute, La Jolla, CA
| | - Jin Huk Choi
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX
| | - Jianhui Wang
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX
| | - Kuan-Wen Wang
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX
| | - Gokhul K Kilaru
- Department of Neuroscience, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX
| | - Jennifer A Mohawk
- Department of Neuroscience, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX
| | - Jiexia Quan
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX
| | - Lindsay Scott
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX
| | - Sara Hildebrand
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX
| | - Xiaohong Li
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX
| | - Miao Tang
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX
| | - Xiaoming Zhan
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX
| | - Anne R Murray
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX
| | - Diantha La Vine
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX
| | - Eva Marie Y Moresco
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX
| | - Joseph S Takahashi
- Department of Neuroscience, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX
| | - Bruce Beutler
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX
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42
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Zhang Z, Ohto U, Shimizu T. Toward a structural understanding of nucleic acid-sensing Toll-like receptors in the innate immune system. FEBS Lett 2017; 591:3167-3181. [PMID: 28686285 DOI: 10.1002/1873-3468.12749] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 06/27/2017] [Accepted: 07/04/2017] [Indexed: 11/12/2022]
Abstract
The history of mankind has been plagued by the tug of war with viral infections. Toll-like receptors (TLRs) and other receptors of the innate immune system constitute an early defense system against invading viruses by recognizing the viral genetic material, the nucleic acids (NAs). Agonistic ligands of NA-sensing TLRs play an emerging role in the treatment of viral diseases, demonstrating a crucial role of these receptors. Recently, crystal structures have afforded new insights into TLR recognition of NAs. An aberrant activation by self-NAs, which leads to the inflammation and autoimmunity, is avoided by strict regulation of NA-TLR interaction at multiple check-points. This Review summarizes the novel structural understanding of NA-sensing by TLRs and regulatory mechanisms of these receptors.
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Affiliation(s)
- Zhikuan Zhang
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Japan
| | - Umeharu Ohto
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Japan
| | - Toshiyuki Shimizu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Japan
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43
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Bugge M, Bergstrom B, Eide OK, Solli H, Kjønstad IF, Stenvik J, Espevik T, Nilsen NJ. Surface Toll-like receptor 3 expression in metastatic intestinal epithelial cells induces inflammatory cytokine production and promotes invasiveness. J Biol Chem 2017; 292:15408-15425. [PMID: 28717003 PMCID: PMC5602399 DOI: 10.1074/jbc.m117.784090] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 07/04/2017] [Indexed: 12/18/2022] Open
Abstract
Toll-like receptors (TLRs) are innate immune receptors for sensing microbial molecules and damage-associated molecular patterns released from host cells. Double-stranded RNA and the synthetic analog polyinosinic:polycytidylic acid (poly(I:C)) bind and activate TLR3. This stimulation leads to recruitment of the adaptor molecule TRIF (Toll/IL-1 resistance (TIR) domain-containing adapter-inducing interferon β) and activation of the transcription factors nuclear factor κB (NF-κB) and interferon regulatory factor 3 (IRF-3), classically inducing IFNβ production. Here we report that, unlike non-metastatic intestinal epithelial cells (IECs), metastatic IECs express TLR3 and that TLR3 promotes invasiveness of these cells. In response to poly(I:C) addition, the metastatic IECs also induced the chemokine CXCL10 in a TLR3-, TRIF-, and IRF3-dependent manner but failed to produce IFNβ. This was in contrast to healthy and non-metastatic IECs, which did not respond to poly(I:C) stimulation. Endolysosomal acidification and the endosomal transporter protein UNC93B1 was required for poly(I:C)-induced CXCL10 production. However, TLR3-induced CXCL10 was triggered by immobilized poly(I:C), was only modestly affected by inhibition of endocytosis, and could be blocked with an anti-TLR3 antibody, indicating that TLR3 can still signal from the cell surface of these cells. Furthermore, plasma membrane fractions from metastatic IECs contained both full-length and cleaved TLR3, demonstrating surface expression of both forms of TLR3. Our results imply that metastatic IECs express surface TLR3, allowing it to sense extracellular stimuli that trigger chemokine responses and promote invasiveness in these cells. We conclude that altered TLR3 expression and localization may have implications for cancer progression.
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Affiliation(s)
- Marit Bugge
- From the Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, 7489 Trondheim, Norway and.,the Clinic of Medicine, St. Olav's University Hospital, 7030 Trondheim, Norway
| | - Bjarte Bergstrom
- From the Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, 7489 Trondheim, Norway and
| | - Oda K Eide
- From the Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, 7489 Trondheim, Norway and
| | - Helene Solli
- From the Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, 7489 Trondheim, Norway and
| | - Ingrid F Kjønstad
- From the Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, 7489 Trondheim, Norway and
| | - Jørgen Stenvik
- From the Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, 7489 Trondheim, Norway and
| | - Terje Espevik
- From the Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, 7489 Trondheim, Norway and
| | - Nadra J Nilsen
- From the Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, 7489 Trondheim, Norway and .,the Clinic of Medicine, St. Olav's University Hospital, 7030 Trondheim, Norway
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44
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Majer O, Liu B, Barton GM. Nucleic acid-sensing TLRs: trafficking and regulation. Curr Opin Immunol 2016; 44:26-33. [PMID: 27907816 DOI: 10.1016/j.coi.2016.10.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 10/28/2016] [Indexed: 12/11/2022]
Abstract
Toll-like receptors (TLRs) play an important role in innate immune responses against pathogenic microorganisms or tissue damage. Nucleic acid (NA)-sensing TLRs localize in intracellular vesicular compartments and recognize foreign-derived and host-derived nucleic acid ligands. Inappropriate activation of NA-sensing TLRs can cause pathogenic inflammation and autoimmunity. Multiple regulatory mechanisms exist to limit recognition of self-NAs. This review summarizes recent progress that has been made in understanding how NA-sensing TLRs are regulated via trafficking, proteolytic cleavage, as well as ligand processing and recognition.
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Affiliation(s)
- Olivia Majer
- Division of Immunology & Pathogenesis, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, United States
| | - Bo Liu
- Division of Immunology & Pathogenesis, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, United States
| | - Gregory M Barton
- Division of Immunology & Pathogenesis, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, United States
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45
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Seo JW, Yang EJ, Kim SH, Choi IH. An inhibitory alternative splice isoform of Toll-like receptor 3 is induced by type I interferons in human astrocyte cell lines. BMB Rep 2016; 48:696-701. [PMID: 26077030 PMCID: PMC4791326 DOI: 10.5483/bmbrep.2015.48.12.106] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Indexed: 01/15/2023] Open
Abstract
Toll-like receptor 3 (TLR3) recognizes viral double-stranded RNA. It stimulates pro-inflammatory cytokine and interferon production. Here we reported the expression of a novel isoform of TLR3 in human astrocyte cell lines whose message is generated by alternative splicing. The isoform represents the N-terminus of the protein. It lacks many of the leucine-rich repeat domains, the transmembrane domain, and the intracellular Toll/interleukin-1 receptor domain of TLR3. Type I interferons (interferon-α and interferon-β) induced the expression of this isoform. Exogenous overexpression of this isoform inhibited interferon regulatory factor 3, signal transducers and activators of transcription 1, and Inhibitor of kappa B α signaling following stimulation. This isoform of TLR3 also inhibited the production of chemokine interferon-γ-inducible protein 10. Our study clearly demonstrated that the expression of this isoform of TLR3 was a negative regulator of signaling pathways and that it was inducible by type I interferons. We also found that this isoform could modulate inflammation in the brain. [BMB Reports 2015; 48(12): 696-701]
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Affiliation(s)
- Jin-Won Seo
- Department of Microbiology, Institute for Immunology and Immunological Diseases, and Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Eun-Jeon Yang
- Department of Microbiology, Institute for Immunology and Immunological Diseases, and Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Se Hoon Kim
- Department of Pathology, Yonsei University College of Medicine, Seoul 03722, Korea
| | - In-Hong Choi
- Department of Microbiology, Institute for Immunology and Immunological Diseases, and Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 03722, Korea
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46
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Pelka K, Shibata T, Miyake K, Latz E. Nucleic acid-sensing TLRs and autoimmunity: novel insights from structural and cell biology. Immunol Rev 2016; 269:60-75. [PMID: 26683145 DOI: 10.1111/imr.12375] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Invasion of pathogenic microorganisms or tissue damage activates innate immune signaling receptors that sample subcellular locations for foreign molecular structures, altered host molecules, or signs of compartment breaches. Upon engagement of innate immune receptors an acute but transient inflammatory response is initiated, aimed at the clearance of pathogens and cellular debris. Among the molecules that are sensed are nucleic acids, which activate several members of the transmembrane Toll-like receptor (TLR) family. Inappropriate recognition of nucleic acids by TLRs can cause inflammatory pathologies and autoimmunity. Here, we review the mechanisms involved in triggering nucleic acid-sensing TLRs and indicate checkpoints that restrict their activation to endolysosomal compartments. These mechanisms are crucial to sample the content of endosomes for nucleic acids in the context of infection or tissue damage, yet prevent accidental activation by host nucleic acids under physiological conditions. Decoding the molecular mechanisms that regulate nucleic acid recognition by TLRs is central to understand pathologies linked to unrestricted nucleic acid sensing and to develop novel therapeutic strategies.
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Affiliation(s)
- Karin Pelka
- Institute of Innate Immunity, University Hospitals Bonn, Bonn, Germany
| | - Takuma Shibata
- Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo, Japan.,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tokyo, Japan
| | - Kensuke Miyake
- Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Eicke Latz
- Institute of Innate Immunity, University Hospitals Bonn, Bonn, Germany.,German Center for Neurodegenerative Diseases, Bonn, Germany.,Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
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47
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Niehl A, Wyrsch I, Boller T, Heinlein M. Double-stranded RNAs induce a pattern-triggered immune signaling pathway in plants. THE NEW PHYTOLOGIST 2016; 211:1008-19. [PMID: 27030513 DOI: 10.1111/nph.13944] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/24/2016] [Indexed: 05/20/2023]
Abstract
Pattern-triggered immunity (PTI) is a plant defense response that relies on the perception of conserved microbe- or pathogen-associated molecular patterns (MAMPs or PAMPs, respectively). Recently, it has been recognized that PTI restricts virus infection in plants; however, the nature of the viral or infection-induced PTI elicitors and the underlying signaling pathways are still unknown. As double-stranded RNAs (dsRNAs) are conserved molecular patterns associated with virus replication, we applied dsRNAs or synthetic dsRNA analogs to Arabidopsis thaliana and investigated PTI responses. We show that in vitro-generated dsRNAs, dsRNAs purified from virus-infected plants and the dsRNA analog polyinosinic-polycytidylic acid (poly(I:C)) induce typical PTI responses dependent on the co-receptor SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE 1 (SERK1), but independent of dicer-like (DCL) proteins in Arabidopsis. Moreover, dsRNA treatment of Arabidopsis induces SERK1-dependent antiviral resistance. Screening of Arabidopsis wild accessions demonstrates natural variability in dsRNA sensitivity. Our findings suggest that dsRNAs represent genuine PAMPs in plants, which induce a signaling cascade involving SERK1 and a specific dsRNA receptor. The dependence of dsRNA-mediated PTI on SERK1, but not on DCLs, implies that dsRNA-mediated PTI involves membrane-associated processes and operates independently of RNA silencing. dsRNA sensitivity may represent a useful trait to increase antiviral resistance in cultivated plants.
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Affiliation(s)
- Annette Niehl
- Botany, Department of Environmental Sciences, University of Basel, Basel, CH-4056, Switzerland
| | - Ines Wyrsch
- Botany, Department of Environmental Sciences, University of Basel, Basel, CH-4056, Switzerland
| | - Thomas Boller
- Botany, Department of Environmental Sciences, University of Basel, Basel, CH-4056, Switzerland
| | - Manfred Heinlein
- Botany, Department of Environmental Sciences, University of Basel, Basel, CH-4056, Switzerland
- Institut de Biologie Moléculaire des Plantes, CNRS UPR 2357, Strasbourg, 67000, France
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48
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Leifer CA, Medvedev AE. Molecular mechanisms of regulation of Toll-like receptor signaling. J Leukoc Biol 2016; 100:927-941. [PMID: 27343013 DOI: 10.1189/jlb.2mr0316-117rr] [Citation(s) in RCA: 184] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 06/01/2016] [Indexed: 01/22/2023] Open
Abstract
TLRs play a critical role in the detection of microbes and endogenous "alarmins" to initiate host defense, yet they can also contribute to the development and progression of inflammatory and autoimmune diseases. To avoid pathogenic inflammation, TLR signaling is subject to multilayer regulatory control mechanisms, including cooperation with coreceptors, post-translational modifications, cleavage, cellular trafficking, and interactions with negative regulators. Nucleic acid-sensing TLRs are particularly interesting in this regard, as they can both recognize host-derived structures and require internalization of their ligand as a result of intracellular sequestration of the nucleic acid-sensing TLRs. This review summarizes the regulatory mechanisms of TLRs, including regulation of their access to ligands, receptor folding, intracellular trafficking, and post-translational modifications, as well as how altered control mechanism could contribute to inflammatory and autoimmune disorders.
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Affiliation(s)
- Cynthia A Leifer
- Department of Microbiology and Immunology, Cornell University, Ithaca, New York, USA; and
| | - Andrei E Medvedev
- Department of Immunology, University of Connecticut Heath Center, Farmington, Connecticut, USA
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49
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Evolutionary redesign of the Atlantic cod (Gadus morhua L.) Toll-like receptor repertoire by gene losses and expansions. Sci Rep 2016; 6:25211. [PMID: 27126702 PMCID: PMC4850435 DOI: 10.1038/srep25211] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 04/07/2016] [Indexed: 02/02/2023] Open
Abstract
Genome sequencing of the teleost Atlantic cod demonstrated loss of the Major Histocompatibility Complex (MHC) class II, an extreme gene expansion of MHC class I and gene expansions and losses in the innate pattern recognition receptor (PRR) family of Toll-like receptors (TLR). In a comparative genomic setting, using an improved version of the genome, we characterize PRRs in Atlantic cod with emphasis on TLRs demonstrating the loss of TLR1/6, TLR2 and TLR5 and expansion of TLR7, TLR8, TLR9, TLR22 and TLR25. We find that Atlantic cod TLR expansions are strongly influenced by diversifying selection likely to increase the detectable ligand repertoire through neo- and subfunctionalization. Using RNAseq we find that Atlantic cod TLRs display likely tissue or developmental stage-specific expression patterns. In a broader perspective, a comprehensive vertebrate TLR phylogeny reveals that the Atlantic cod TLR repertoire is extreme with regards to losses and expansions compared to other teleosts. In addition we identify a substantial shift in TLR repertoires following the evolutionary transition from an aquatic vertebrate (fish) to a terrestrial (tetrapod) life style. Collectively, our findings provide new insight into the function and evolution of TLRs in Atlantic cod as well as the evolutionary history of vertebrate innate immunity.
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50
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Abstract
Salmonella enterica is an intracellular pathogen that causes diseases ranging from gastroenteritis to typhoid fever. Salmonella bacteria trigger an autophagic response in host cells upon infection but have evolved mechanisms for suppressing this response, thereby enhancing intracellular survival. We recently reported that S. enterica serovar Typhimurium actively recruits the host tyrosine kinase focal adhesion kinase (FAK) to the surface of the Salmonella-containing vacuole (SCV) (K. A. Owen et al., PLoS Pathog 10:e1004159, 2014). FAK then suppresses autophagy through activation of the Akt/mTORC1 signaling pathway. In FAK−/− macrophages, bacteria are captured in autophagosomes and intracellular survival is attenuated. Here we show that the cell-autonomous bacterial suppression of autophagy also suppresses the broader innate immune response by inhibiting production of beta interferon (IFN-β). Induction of bacterial autophagy (xenophagy), but not autophagy alone, triggers IFN-β production through a pathway involving the adapter TRIF and endosomal Toll-like receptor 3 (TLR3) and TLR4. Selective FAK knockout in macrophages resulted in rapid bacterial clearance from mucosal tissues after oral infection. Clearance correlated with increased IFN-β production by intestinal macrophages and with IFN-β-dependent induction of IFN-γ by intestinal NK cells. Blockade of either IFN-β or IFN-γ increased host susceptibility to infection, whereas experimental induction of IFN-β was protective. Thus, bacterial suppression of autophagy not only enhances cell-autonomous survival but also suppresses more-systemic innate immune responses by limiting type I and type II interferons. Salmonella enterica serovar Typhimurium represents one of the most commonly identified bacterial causes of foodborne illness worldwide. S. Typhimurium has developed numerous strategies to evade detection by the host immune system. Autophagy is a cellular process that involves the recognition and degradation of defective proteins and organelles. More recently, autophagy has been described as an important means by which host cells recognize and eliminate invading intracellular pathogens and plays a key role in the production of cytokines. Previously, we determined that Salmonella bacteria are able to suppress their own autophagic capture and elimination by macrophages. Building on that study, we show here that the inhibition of autophagy by Salmonella also prevents the induction of a protective cytokine response mediated by beta interferon (IFN-β) and IFN-γ. Together, these findings identify a novel virulence strategy whereby Salmonella bacteria prevent cell autonomous elimination via autophagy and suppress the activation of innate immune responses.
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