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Nisar H, Sanchidrián González PM, Labonté FM, Schmitz C, Roggan MD, Kronenberg J, Konda B, Chevalier F, Hellweg CE. NF-κB in the Radiation Response of A549 Non-Small Cell Lung Cancer Cells to X-rays and Carbon Ions under Hypoxia. Int J Mol Sci 2024; 25:4495. [PMID: 38674080 PMCID: PMC11050661 DOI: 10.3390/ijms25084495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 04/08/2024] [Accepted: 04/17/2024] [Indexed: 04/28/2024] Open
Abstract
Cellular hypoxia, detectable in up to 80% of non-small cell lung carcinoma (NSCLC) tumors, is a known cause of radioresistance. High linear energy transfer (LET) particle radiation might be effective in the treatment of hypoxic solid tumors, including NSCLC. Cellular hypoxia can activate nuclear factor κB (NF-κB), which can modulate radioresistance by influencing cancer cell survival. The effect of high-LET radiation on NF-κB activation in hypoxic NSCLC cells is unclear. Therefore, we compared the effect of low (X-rays)- and high (12C)-LET radiation on NF-κB responsive genes' upregulation, as well as its target cytokines' synthesis in normoxic and hypoxic A549 NSCLC cells. The cells were incubated under normoxia (20% O2) or hypoxia (1% O2) for 48 h, followed by irradiation with 8 Gy X-rays or 12C ions, maintaining the oxygen conditions until fixation or lysis. Regulation of NF-κB responsive genes was evaluated by mRNA sequencing. Secretion of NF-κB target cytokines, IL-6 and IL-8, was quantified by ELISA. A greater fold change increase in expression of NF-κB target genes in A549 cells following exposure to 12C ions compared to X-rays was observed, regardless of oxygenation status. These genes regulate cell migration, cell cycle, and cell survival. A greater number of NF-κB target genes was activated under hypoxia, regardless of irradiation status. These genes regulate cell migration, survival, proliferation, and inflammation. X-ray exposure under hypoxia additionally upregulated NF-κB target genes modulating immunosurveillance and epithelial-mesenchymal transition (EMT). Increased IL-6 and IL-8 secretion under hypoxia confirmed NF-κB-mediated expression of pro-inflammatory genes. Therefore, radiotherapy, particularly with X-rays, may increase tumor invasiveness in surviving hypoxic A549 cells.
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Affiliation(s)
- Hasan Nisar
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), 51147 Cologne, Germany; (H.N.); (P.M.S.G.); (J.K.); (B.K.)
- Department of Medical Sciences, Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad 44000, Pakistan
| | - Paulina Mercedes Sanchidrián González
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), 51147 Cologne, Germany; (H.N.); (P.M.S.G.); (J.K.); (B.K.)
| | - Frederik M. Labonté
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), 51147 Cologne, Germany; (H.N.); (P.M.S.G.); (J.K.); (B.K.)
| | - Claudia Schmitz
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), 51147 Cologne, Germany; (H.N.); (P.M.S.G.); (J.K.); (B.K.)
| | - Marie Denise Roggan
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), 51147 Cologne, Germany; (H.N.); (P.M.S.G.); (J.K.); (B.K.)
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Jessica Kronenberg
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), 51147 Cologne, Germany; (H.N.); (P.M.S.G.); (J.K.); (B.K.)
- Microgravity User Support Center (MUSC), German Aerospace Center (DLR), 51147 Cologne, Germany
| | - Bikash Konda
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), 51147 Cologne, Germany; (H.N.); (P.M.S.G.); (J.K.); (B.K.)
| | - François Chevalier
- UMR6252 CIMAP, CEA-CNRS-ENSICAEN-University of Caen Normandy, 14000 Caen, France;
| | - Christine E. Hellweg
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), 51147 Cologne, Germany; (H.N.); (P.M.S.G.); (J.K.); (B.K.)
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Qiao D, Xu X, Zhang Y, Yang J, Brasier AR. RSV replication modifies the XBP1s binding complex on the IRF1 upstream enhancer to potentiate the mucosal anti-viral response. Front Immunol 2023; 14:1197356. [PMID: 37564646 PMCID: PMC10411192 DOI: 10.3389/fimmu.2023.1197356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 07/06/2023] [Indexed: 08/12/2023] Open
Abstract
Introduction The unfolded protein response (UPR) has emerged as an important signaling pathway mediating anti-viral defenses to Respiratory Syncytial Virus (RSV) infection. Earlier we found that RSV replication predominantly activates the evolutionarily conserved Inositol Requiring Enzyme 1α (IRE1α)-X-Box Binding Protein 1 spliced (XBP1s) arm of the Unfolded Protein Response (UPR) producing inflammation, metabolic adaptation and cellular plasticity, yet the mechanisms how the UPR potentiates inflammation are not well understood. Methods To understand this process better, we examined the genomic response integrating RNA-seq and Cleavage Under Targets and Release Using Nuclease (CUT&RUN) analyses. These data were integrated with an RNA-seq analysis conducted on RSV-infected small airway cells ± an IRE1α RNAse inhibitor. Results We identified RSV induced expression changes in ~3.2K genes; of these, 279 required IRE1α and were enriched in IL-10/cytokine signaling pathways. From this data set, we identify those genes directly under XBP1s control by CUT&RUN. Although XBP1s binds to ~4.2 K high-confidence genomic binding sites, surprisingly only a small subset of IL10/cytokine signaling genes are directly bound. We further apply CUT&RUN to find that RSV infection enhances XBP1s loading on 786 genomic sites enriched in AP1/Fra-1, RELA and SP1 binding sites. These control a subset of cytokine regulatory factor genes including IFN response factor 1 (IRF1), CSF2, NFKB1A and DUSP10. Focusing on the downstream role of IRF1, selective knockdown (KD) and overexpression experiments demonstrate IRF1 induction controls type I and -III interferon (IFN) and IFN-stimulated gene (ISG) expression, demonstrating that ISG are indirectly regulated by XBP1 through IRF1 transactivation. Examining the mechanism of IRF1 activation, we observe that XBP1s directly binds a 5' enhancer sequence whose XBP1s loading is increased by RSV. The functional requirement for the enhancer is demonstrated by targeting a dCas9-KRAB silencer, reducing IRF1 activation. Chromatin immunoprecipitation shows that XBP1 is required, but not sufficient, for RSV-induced recruitment of activated phospho-Ser2 Pol II to the enhancer. Discussion We conclude that XBP1s is a direct activator of a core subset of IFN and cytokine regulatory genes in response to RSV. Of these IRF1 is upstream of the type III IFN and ISG response. We find that RSV modulates the XBP1s binding complex on the IRF1 5' enhancer whose activation is required for IRF1 expression. These findings provide novel insight into how the IRE1α-XBP1s pathway potentiates airway mucosal anti-viral responses.
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Affiliation(s)
- Dianhua Qiao
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Xiaofang Xu
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Yueqing Zhang
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - Jun Yang
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - Allan R. Brasier
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
- Institute for Clinical and Translational Research (ICTR), University of Wisconsin-Madison, Madison, WI, United States
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Mann MW, Fu Y, Gearhart RL, Xu X, Roberts DS, Li Y, Zhou J, Ge Y, Brasier AR. Bromodomain-containing Protein 4 regulates innate inflammation via modulation of alternative splicing. Front Immunol 2023; 14:1212770. [PMID: 37435059 PMCID: PMC10331468 DOI: 10.3389/fimmu.2023.1212770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 06/05/2023] [Indexed: 07/13/2023] Open
Abstract
Introduction Bromodomain-containing Protein 4 (BRD4) is a transcriptional regulator which coordinates gene expression programs controlling cancer biology, inflammation, and fibrosis. In the context of airway viral infection, BRD4-specific inhibitors (BRD4i) block the release of pro-inflammatory cytokines and prevent downstream epithelial plasticity. Although the chromatin modifying functions of BRD4 in inducible gene expression have been extensively investigated, its roles in post-transcriptional regulation are not well understood. Given BRD4's interaction with the transcriptional elongation complex and spliceosome, we hypothesize that BRD4 is a functional regulator of mRNA processing. Methods To address this question, we combine data-independent analysis - parallel accumulation-serial fragmentation (diaPASEF) with RNA-sequencing to achieve deep and integrated coverage of the proteomic and transcriptomic landscapes of human small airway epithelial cells exposed to viral challenge and treated with BRD4i. Results We discover that BRD4 regulates alternative splicing of key genes, including Interferon-related Developmental Regulator 1 (IFRD1) and X-Box Binding Protein 1 (XBP1), related to the innate immune response and the unfolded protein response (UPR). We identify requirement of BRD4 for expression of serine-arginine splicing factors, splicosome components and the Inositol-Requiring Enzyme 1 IREα affecting immediate early innate response and the UPR. Discussion These findings extend the transcriptional elongation-facilitating actions of BRD4 in control of post-transcriptional RNA processing via modulating splicing factor expression in virus-induced innate signaling.
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Affiliation(s)
- Morgan W. Mann
- Department of Medicine, University of Wisconsin – Madison, Madison, WI, United States
| | - Yao Fu
- Department of Medicine, University of Wisconsin – Madison, Madison, WI, United States
| | - Robert L. Gearhart
- Department of Chemistry, University of Wisconsin – Madison, Madison, WI, United States
| | - Xiaofang Xu
- Department of Medicine, University of Wisconsin – Madison, Madison, WI, United States
| | - David S. Roberts
- Department of Chemistry, University of Wisconsin – Madison, Madison, WI, United States
| | - Yi Li
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, United States
| | - Jia Zhou
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, United States
| | - Ying Ge
- Department of Chemistry, University of Wisconsin – Madison, Madison, WI, United States
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI, United States
- Human Proteomics Program, University of Wisconsin-Madison, Madison, WI, United States
| | - Allan R. Brasier
- Department of Medicine, University of Wisconsin – Madison, Madison, WI, United States
- Institute for Clinical and Translational Research, University of Wisconsin-Madison, Madison, WI, United States
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Mann M, Fu Y, Xu X, Roberts DS, Li Y, Zhou J, Ge Y, Brasier AR. Bromodomain-containing Protein 4 Regulates Innate Inflammation in Airway Epithelial Cells via Modulation of Alternative Splicing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.17.524257. [PMID: 36711789 PMCID: PMC9882210 DOI: 10.1101/2023.01.17.524257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Bromodomain-containing Protein 4 (BRD4) is a transcriptional regulator which coordinates gene expression programs controlling cancer biology, inflammation, and fibrosis. In airway viral infection, non-toxic BRD4-specific inhibitors (BRD4i) block the release of pro-inflammatory cytokines and prevent downstream remodeling. Although the chromatin modifying functions of BRD4 in inducible gene expression have been extensively investigated, its roles in post-transcriptional regulation are not as well understood. Based on its interaction with the transcriptional elongation complex and spliceosome, we hypothesize that BRD4 is a functional regulator of mRNA processing. To address this question, we combine data-independent analysis - parallel accumulation-serial fragmentation (diaPASEF) with RNA-sequencing to achieve deep and integrated coverage of the proteomic and transcriptomic landscapes of human small airway epithelial cells exposed to viral challenge and treated with BRD4i. The transcript-level data was further interrogated for alternative splicing analysis, and the resulting data sets were correlated to identify pathways subject to post-transcriptional regulation. We discover that BRD4 regulates alternative splicing of key genes, including Interferon-related Developmental Regulator 1 ( IFRD1 ) and X-Box Binding Protein 1 ( XBP1 ), related to the innate immune response and the unfolded protein response, respectively. These findings extend the transcriptional elongation-facilitating actions of BRD4 in control of post-transcriptional RNA processing in innate signaling.
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Affiliation(s)
- Morgan Mann
- Department of Medicine, University of Wisconsin – Madison, Madison, 53705, Wisconsin, USA
| | - Yao Fu
- Department of Medicine, University of Wisconsin – Madison, Madison, 53705, Wisconsin, USA
| | - Xiaofang Xu
- Department of Medicine, University of Wisconsin – Madison, Madison, 53705, Wisconsin, USA
| | - David S. Roberts
- Department of Chemistry, University of Wisconsin – Madison, Madison, 53705, Wisconsin, USA
| | - Yi Li
- Department of Pharmacology and Toxicology, University of Texas, Medical Branch, Galveston, 77550, Texas, USA
| | - Jia Zhou
- Department of Pharmacology and Toxicology, University of Texas, Medical Branch, Galveston, 77550, Texas, USA
| | - Ying Ge
- Department of Chemistry, University of Wisconsin – Madison, Madison, 53705, Wisconsin, USA,Human Proteomics Program, University of Wisconsin – Madison, Madison, 53705, Wisconsin, USA,Department of Cell and Regenerative Biology, University of Wisconsin – Madison, Madison, 53705, Wisconsin, USA
| | - Allan R. Brasier
- Institute for Clinical and Translational Research (ICTR), University of Wisconsin – Madison, Madison, 53705, Wisconsin, USA
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Córdova-Dávalos LE, Hernández-Mercado A, Barrón-García CB, Rojas-Martínez A, Jiménez M, Salinas E, Cervantes-García D. Impact of genetic polymorphisms related to innate immune response on respiratory syncytial virus infection in children. Virus Genes 2022; 58:501-514. [PMID: 36085536 PMCID: PMC9462631 DOI: 10.1007/s11262-022-01932-6] [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: 03/25/2022] [Accepted: 08/30/2022] [Indexed: 11/24/2022]
Abstract
Respiratory syncytial virus (RSV) causes lower respiratory tract infections and bronchiolitis, mainly affecting children under 2 years of age and immunocompromised patients. Currently, there are no available vaccines or efficient pharmacological treatments against RSV. In recent years, tremendous efforts have been directed to understand the pathological mechanisms of the disease and generate a vaccine against RSV. Although RSV is highly infectious, not all the patients who get infected develop bronchiolitis and severe disease. Through various sequencing studies, single nucleotide polymorphisms (SNPs) have been discovered in diverse receptors, cytokines, and transcriptional regulators with crucial role in the activation of the innate immune response, which is implicated in the susceptibility to develop or protect from severe forms of the infection. In this review, we highlighted how variations in the key genes affect the development of innate immune response against RSV. This data would provide crucial information about the mechanisms of viral infection, and in the future, could help in generation of new strategies for vaccine development or generation of the pharmacological treatments.
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Affiliation(s)
- Laura Elena Córdova-Dávalos
- Laboratorio de Inmunología, Departamento de Microbiología, Universidad Autónoma de Aguascalientes, 20100, Aguascalientes, México
| | - Alicia Hernández-Mercado
- Laboratorio de Inmunología, Departamento de Microbiología, Universidad Autónoma de Aguascalientes, 20100, Aguascalientes, México
| | - Claudia Berenice Barrón-García
- Laboratorio de Inmunología, Departamento de Microbiología, Universidad Autónoma de Aguascalientes, 20100, Aguascalientes, México
| | - Augusto Rojas-Martínez
- Tecnológico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Av. Morones Prieto 3000 Pte, Los Doctores, 64710, Monterrey, Nuevo León, México
| | - Mariela Jiménez
- Laboratorio de Inmunología, Departamento de Microbiología, Universidad Autónoma de Aguascalientes, 20100, Aguascalientes, México
| | - Eva Salinas
- Laboratorio de Inmunología, Departamento de Microbiología, Universidad Autónoma de Aguascalientes, 20100, Aguascalientes, México.
| | - Daniel Cervantes-García
- Laboratorio de Inmunología, Departamento de Microbiología, Universidad Autónoma de Aguascalientes, 20100, Aguascalientes, México. .,Consejo Nacional de Ciencia y Tecnología, 03940, Ciudad de México, México.
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Kusiak A, Brady G. Bifurcation of signalling in human innate immune pathways to NF-kB and IRF family activation. Biochem Pharmacol 2022; 205:115246. [PMID: 36088989 DOI: 10.1016/j.bcp.2022.115246] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 09/01/2022] [Accepted: 09/02/2022] [Indexed: 11/28/2022]
Abstract
The human innate immune response can be activated through a wide range of stimuli. This multi-faceted system can be triggered by a range of immunostimulants including pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). These stimuli drive intracellular signalling pathways that branch off downstream to activate several distinct transcription factors. The two most impactful of which in innate immune outcomes are the NF-κB and the IRF family members. Both transcription factor families play defining roles in driving inflammation as well as the antiviral response. Pathways leading to their simultaneous activation share common upstream components but eventually distinct regulators which directly facilitate their activation. This review will discuss the current state of knowledge about what is known about how these pathways bifurcate to activate NF-κB and IRF family members.
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Affiliation(s)
- Aleksandra Kusiak
- Trinity Translational Medicine Institute, St James' Campus, Trinity College Dublin, D08 W9RT Dublin, Ireland.
| | - Gareth Brady
- Trinity Translational Medicine Institute, St James' Campus, Trinity College Dublin, D08 W9RT Dublin, Ireland.
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Jamaluddin M, Haas de Mello A, Tapryal N, Hazra TK, Garofalo RP, Casola A. NRF2 Regulates Cystathionine Gamma-Lyase Expression and Activity in Primary Airway Epithelial Cells Infected with Respiratory Syncytial Virus. Antioxidants (Basel) 2022; 11:1582. [PMID: 36009301 PMCID: PMC9405023 DOI: 10.3390/antiox11081582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 08/08/2022] [Accepted: 08/12/2022] [Indexed: 11/16/2022] Open
Abstract
Cystathionine-y-lyase (CSE) is a critical enzyme for hydrogen sulfide (H2S) biosynthesis and plays a key role in respiratory syncytial virus (RSV) pathogenesis. The transcription factor NRF2 is the master regulator of cytoprotective and antioxidant gene expression, and is degraded during RSV infection. While some evidence supports the role of NRF2 in CSE gene transcription, its role in CSE expression in airway epithelial cells is not known. Here, we show that RSV infection decreased CSE expression and activity in primary small airway epithelial (SAE) cells, while treatment with tert-butylhydroquinone (tBHQ), an NRF2 inducer, led to an increase of both. Using reporter gene assays, we identified an NRF2 response element required for the NRF2 inducible expression of the CSE promoter. Electrophoretic mobility shift assays demonstrated inducible specific NRF2 binding to the DNA probe corresponding to the putative CSE promoter NRF2 binding sequence. Using chromatin immunoprecipitation assays, we found a 50% reduction in NRF2 binding to the endogenous CSE proximal promoter in SAE cells infected with RSV, and increased binding in cells stimulated with tBHQ. Our results support the hypothesis that NRF2 regulates CSE gene transcription in airway epithelial cells, and that RSV-induced NRF2 degradation likely accounts for the observed reduced CSE expression and activity.
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Affiliation(s)
- Mohammad Jamaluddin
- Department of Pediatrics, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Aline Haas de Mello
- Department of Pediatrics, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Nisha Tapryal
- Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Tapas K. Hazra
- Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Roberto P. Garofalo
- Department of Pediatrics, The University of Texas Medical Branch, Galveston, TX 77555, USA
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Antonella Casola
- Department of Pediatrics, The University of Texas Medical Branch, Galveston, TX 77555, USA
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77555, USA
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The IRE1α-XBP1s Arm of the Unfolded Protein Response Activates N-Glycosylation to Remodel the Subepithelial Basement Membrane in Paramyxovirus Infection. Int J Mol Sci 2022; 23:ijms23169000. [PMID: 36012265 PMCID: PMC9408905 DOI: 10.3390/ijms23169000] [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: 06/25/2022] [Revised: 07/29/2022] [Accepted: 08/09/2022] [Indexed: 11/16/2022] Open
Abstract
Respiratory syncytial virus (RSV) causes severe lower respiratory tract infections (LRTI) associated with decreased pulmonary function, asthma, and allergy. Recently, we demonstrated that RSV induces the hexosamine biosynthetic pathway via the unfolded protein response (UPR), which is a pathway controlling protein glycosylation and secretion of the extracellular matrix (ECM). Because the presence of matrix metalloproteinases and matricellular growth factors (TGF) is associated with severe LRTI, we studied the effect of RSV on ECM remodeling and found that RSV enhances the deposition of fibronectin-rich ECM by small airway epithelial cells in a manner highly dependent on the inositol requiring kinase (IRE1α)–XBP1 arm of the UPR. To understand this effect comprehensively, we applied pharmacoproteomics to understand the effect of the UPR on N-glycosylation and ECM secretion in RSV infection. We observe that RSV induces N-glycosylation and the secretion of proteins related to ECM organization, secretion, or proteins integral to plasma membranes, such as integrins, laminins, collagens, and ECM-modifying enzymes, in an IRE1α–XBP1 dependent manner. Using a murine paramyxovirus model that activates the UPR in vivo, we validate the IRE1α–XBP1-dependent secretion of ECM to alveolar space. This study extends understanding of the IRE1α–XBP1 pathway in regulating N-glycosylation coupled to structural remodeling of the epithelial basement membrane in RSV infection.
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RELA∙8-Oxoguanine DNA Glycosylase1 Is an Epigenetic Regulatory Complex Coordinating the Hexosamine Biosynthetic Pathway in RSV Infection. Cells 2022; 11:cells11142210. [PMID: 35883652 PMCID: PMC9319012 DOI: 10.3390/cells11142210] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 07/12/2022] [Accepted: 07/12/2022] [Indexed: 11/16/2022] Open
Abstract
Respiratory syncytial virus (RSV), or human orthopneumovirus, is a negative-sense RNA virus that is the causative agent of severe lower respiratory tract infections in children and is associated with exacerbations of adult lung disease. The mechanisms how severe and/or repetitive virus infections cause declines in pulmonary capacity are not fully understood. We have recently discovered that viral replication triggers epithelial plasticity and metabolic reprogramming involving the hexosamine biosynthetic pathway (HBP). In this study, we examine the relationship between viral induced innate inflammation and the activation of hexosamine biosynthesis in small airway epithelial cells. We observe that RSV induces ~2-fold accumulation of intracellular UDP-GlcNAc, the end-product of the HBP and the obligate substrate of N glycosylation. Using two different silencing approaches, we observe that RSV replication activates the HBP pathway in a manner dependent on the RELA proto-oncogene (65 kDa subunit). To better understand the effect of RSV on the cellular N glycoproteome, and its RELA dependence, we conduct affinity enriched LC-MS profiling in wild-type and RELA-silenced cells. We find that RSV induces the accumulation of 171 N glycosylated peptides in a RELA-dependent manner; these proteins are functionally enriched in integrins and basal lamina formation. To elaborate this mechanism of HBP expression, we demonstrate that RSV infection coordinately induces the HBP pathway enzymes in a manner requiring RELA; these genes include Glutamine-Fructose-6-Phosphate Transaminase 1 (GFPT)-1/2, Glucosamine-Phosphate N-Acetyltransferase (GNPNAT)-1, phosphoglucomutase (PGM)-3 and UDP-N-Acetylglucosamine Pyrophosphorylase (UAP)-1. Using small-molecule inhibitor(s) of 8-oxoguanine DNA glycosylase1 (OGG1), we observe that OGG1 is also required for the expression of HBP pathway. In proximity ligation assays, RSV induces the formation of a nuclear and mitochondrial RELA∙OGG1 complex. In co-immunoprecipitaton (IP) experiments, we discover that RSV induces Ser 536-phosphorylated RELA to complex with OGG1. Chromatin IP experiments demonstrate a major role of OGG1 in supporting the recruitment of RELA and phosphorylated RNA Pol II to the HBP pathway genes. We conclude that the RELA∙OGG1 complex is an epigenetic regulator mediating metabolic reprogramming and N glycoprotein modifications of integrins in response to RSV. These findings have implications for viral-induced adaptive epithelial responses.
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Van Royen T, Rossey I, Sedeyn K, Schepens B, Saelens X. How RSV Proteins Join Forces to Overcome the Host Innate Immune Response. Viruses 2022; 14:v14020419. [PMID: 35216012 PMCID: PMC8874859 DOI: 10.3390/v14020419] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/11/2022] [Accepted: 02/14/2022] [Indexed: 12/10/2022] Open
Abstract
Respiratory syncytial virus (RSV) is the leading cause of severe acute lower respiratory tract infections in infants worldwide. Although several pattern recognition receptors (PRRs) can sense RSV-derived pathogen-associated molecular patterns (PAMPs), infection with RSV is typically associated with low to undetectable levels of type I interferons (IFNs). Multiple RSV proteins can hinder the host’s innate immune response. The main players are NS1 and NS2 which suppress type I IFN production and signalling in multiple ways. The recruitment of innate immune cells and the production of several cytokines are reduced by RSV G. Next, RSV N can sequester immunostimulatory proteins to inclusion bodies (IBs). N might also facilitate the assembly of a multiprotein complex that is responsible for the negative regulation of innate immune pathways. Furthermore, RSV M modulates the host’s innate immune response. The nuclear accumulation of RSV M has been linked to an impaired host gene transcription, in particular for nuclear-encoded mitochondrial proteins. In addition, RSV M might also directly target mitochondrial proteins which results in a reduced mitochondrion-mediated innate immune recognition of RSV. Lastly, RSV SH might prolong the viral replication in infected cells and influence cytokine production.
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Affiliation(s)
- Tessa Van Royen
- VIB-UGent Center for Medical Biotechnology, VIB, 9000 Ghent, Belgium; (T.V.R.); (I.R.); (K.S.); (B.S.)
- Department for Biochemistry and Microbiology, Ghent University, 9000 Ghent, Belgium
| | - Iebe Rossey
- VIB-UGent Center for Medical Biotechnology, VIB, 9000 Ghent, Belgium; (T.V.R.); (I.R.); (K.S.); (B.S.)
- Department for Biochemistry and Microbiology, Ghent University, 9000 Ghent, Belgium
| | - Koen Sedeyn
- VIB-UGent Center for Medical Biotechnology, VIB, 9000 Ghent, Belgium; (T.V.R.); (I.R.); (K.S.); (B.S.)
- Department for Biochemistry and Microbiology, Ghent University, 9000 Ghent, Belgium
| | - Bert Schepens
- VIB-UGent Center for Medical Biotechnology, VIB, 9000 Ghent, Belgium; (T.V.R.); (I.R.); (K.S.); (B.S.)
- Department for Biochemistry and Microbiology, Ghent University, 9000 Ghent, Belgium
| | - Xavier Saelens
- VIB-UGent Center for Medical Biotechnology, VIB, 9000 Ghent, Belgium; (T.V.R.); (I.R.); (K.S.); (B.S.)
- Department for Biochemistry and Microbiology, Ghent University, 9000 Ghent, Belgium
- Correspondence:
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11
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Martín-Vicente M, Resino S, Martínez I. Early innate immune response triggered by the human respiratory syncytial virus and its regulation by ubiquitination/deubiquitination processes. J Biomed Sci 2022; 29:11. [PMID: 35152905 PMCID: PMC8841119 DOI: 10.1186/s12929-022-00793-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 01/28/2022] [Indexed: 12/25/2022] Open
Abstract
The human respiratory syncytial virus (HRSV) causes severe lower respiratory tract infections in infants and the elderly. An exuberant inadequate immune response is behind most of the pathology caused by the HRSV. The main targets of HRSV infection are the epithelial cells of the respiratory tract, where the immune response against the virus begins. This early innate immune response consists of the expression of hundreds of pro-inflammatory and anti-viral genes that stimulates subsequent innate and adaptive immunity. The early innate response in infected cells is mediated by intracellular signaling pathways composed of pattern recognition receptors (PRRs), adapters, kinases, and transcriptions factors. These pathways are tightly regulated by complex networks of post-translational modifications, including ubiquitination. Numerous ubiquitinases and deubiquitinases make these modifications reversible and highly dynamic. The intricate nature of the signaling pathways and their regulation offers the opportunity for fine-tuning the innate immune response against HRSV to control virus replication and immunopathology.
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12
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Rayavara K, Kurosky A, Hosakote YM. Respiratory syncytial virus infection induces the release of transglutaminase 2 from human airway epithelial cells. Am J Physiol Lung Cell Mol Physiol 2022; 322:L1-L12. [PMID: 34704843 PMCID: PMC8721898 DOI: 10.1152/ajplung.00013.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Respiratory syncytial virus (RSV) is an important human pathogen that causes severe lower respiratory tract infections in young children, the elderly, and the immunocompromised, yet no effective treatments or vaccines are available. The precise mechanism underlying RSV-induced acute airway disease and associated sequelae are not fully understood; however, early lung inflammatory and immune events are thought to play a major role in the outcome of the disease. Moreover, oxidative stress responses in the airways play a key role in the pathogenesis of RSV. Oxidative stress has been shown to elevate cytosolic calcium (Ca2+) levels, which in turn activate Ca2+-dependent enzymes, including transglutaminase 2 (TG2). Transglutaminase 2 is a multifunctional cross-linking enzyme implicated in various physiological and pathological conditions; however, its involvement in respiratory virus-induced airway inflammation is largely unknown. In this study, we demonstrated that RSV-induced oxidative stress promotes enhanced activation and release of TG2 from human lung epithelial cells as a result of its translocation from the cytoplasm and subsequent release into the extracellular space, which was mediated by Toll-like receptor (TLR)-4 and NF-κB pathways. Antioxidant treatment significantly inhibited RSV-induced TG2 extracellular release and activation via blocking viral replication. Also, treatment of RSV-infected lung epithelial cells with TG2 inhibitor significantly reduced RSV-induced matrix metalloprotease activities. These results suggested that RSV-induced oxidative stress activates innate immune receptors in the airways, such as TLRs, that can activate TG2 via the NF-κB pathway to promote cross-linking of extracellular matrix proteins, resulting in enhanced inflammation.
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Affiliation(s)
- Kempaiah Rayavara
- 1Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas
| | - Alexander Kurosky
- 2Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Texas
| | - Yashoda M. Hosakote
- 1Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas
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13
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Xu X, Mann M, Qiao D, Li Y, Zhou J, Brasier AR. Bromodomain Containing Protein 4 (BRD4) Regulates Expression of its Interacting Coactivators in the Innate Response to Respiratory Syncytial Virus. Front Mol Biosci 2021; 8:728661. [PMID: 34765643 PMCID: PMC8577543 DOI: 10.3389/fmolb.2021.728661] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 09/24/2021] [Indexed: 12/12/2022] Open
Abstract
Bromodomain-containing protein 4 plays a central role in coordinating the complex epigenetic component of the innate immune response. Previous studies implicated BRD4 as a component of a chromatin-modifying complex that is dynamically recruited to a network of protective cytokines by binding activated transcription factors, polymerases, and histones to trigger their rapid expression via transcriptional elongation. Our previous study extended our understanding of the airway epithelial BRD4 interactome by identifying over 100 functionally important coactivators and transcription factors, whose association is induced by respiratory syncytial virus (RSV) infection. RSV is an etiological agent of recurrent respiratory tract infections associated with exacerbations of chronic obstructive pulmonary disease. Using a highly selective small-molecule BRD4 inhibitor (ZL0454) developed by us, we extend these findings to identify the gene regulatory network dependent on BRD4 bromodomain (BD) interactions. Human small airway epithelial cells were infected in the absence or presence of ZL0454, and gene expression profiling was performed. A highly reproducible dataset was obtained which indicated that BRD4 mediates both activation and repression of RSV-inducible gene regulatory networks controlling cytokine expression, interferon (IFN) production, and extracellular matrix remodeling. Index genes of functionally significant clusters were validated independently. We discover that BRD4 regulates the expression of its own gene during the innate immune response. Interestingly, BRD4 activates the expression of NFκB/RelA, a coactivator that binds to BRD4 in a BD-dependent manner. We extend this finding to show that BRD4 also regulates other components of its functional interactome, including the Mediator (Med) coactivator complex and the SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin (SMARC) subunits. To provide further insight into mechanisms for BRD4 in RSV expression, we mapped 7,845 RSV-inducible Tn5 transposase peaks onto the BRD4-dependent gene bodies. These were located in promoters and introns of cytostructural and extracellular matrix (ECM) formation genes. These data indicate that BRD4 mediates the dynamic response of airway epithelial cells to RNA infection by modulating the expression of its coactivators, controlling the expression of host defense mechanisms and remodeling genes through changes in promoter accessibility.
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Affiliation(s)
- Xiaofang Xu
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Morgan Mann
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Dianhua Qiao
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Yi Li
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, United States
| | - Jia Zhou
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, United States
| | - Allan R Brasier
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States.,Institute for Clinical and Translational Research (ICTR), University of Wisconsin-Madison, Madison, WI, United States
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14
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Qiao D, Skibba M, Xu X, Garofalo RP, Zhao Y, Brasier AR. Paramyxovirus replication induces the hexosamine biosynthetic pathway and mesenchymal transition via the IRE1α-XBP1s arm of the unfolded protein response. Am J Physiol Lung Cell Mol Physiol 2021; 321:L576-L594. [PMID: 34318710 PMCID: PMC8461800 DOI: 10.1152/ajplung.00127.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The paramyxoviridae, respiratory syncytial virus (RSV), and murine respirovirus are enveloped, negative-sense RNA viruses that are the etiological agents of vertebrate lower respiratory tract infections (LRTIs). We observed that RSV infection in human small airway epithelial cells induced accumulation of glycosylated proteins within the endoplasmic reticulum (ER), increased glutamine-fructose-6-phosphate transaminases (GFPT1/2) and accumulation of uridine diphosphate (UDP)-N-acetylglucosamine, indicating activation of the hexosamine biosynthetic pathway (HBP). RSV infection induces rapid formation of spliced X-box binding protein 1 (XBP1s) and processing of activating transcription factor 6 (ATF6). Using pathway selective inhibitors and shRNA silencing, we find that the inositol-requiring enzyme (IRE1α)-XBP1 arm of the unfolded protein response (UPR) is required not only for activation of the HBP, but also for expression of mesenchymal transition (EMT) through the Snail family transcriptional repressor 1 (SNAI1), extracellular matrix (ECM)-remodeling proteins fibronectin (FN1), and matrix metalloproteinase 9 (MMP9). Probing RSV-induced open chromatin domains by ChIP, we find XBP1 binds and recruits RNA polymerase II to the IL6, SNAI1, and MMP9 promoters and the intragenic superenhancer of glutamine-fructose-6-phosphate transaminase 2 (GFPT2). The UPR is sustained through RSV by an autoregulatory loop where XBP1 enhances Pol II binding to its own promoter. Similarly, we investigated the effects of murine respirovirus infection on its natural host (mouse). Murine respirovirus induces mucosal growth factor response, EMT, and the indicators of ECM remodeling in an IRE1α-dependent manner, which persists after viral clearance. These data suggest that IRE1α-XBP1s arm of the UPR pathway is responsible for paramyxovirus-induced metabolic adaptation and mucosal remodeling via EMT and ECM secretion.
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Affiliation(s)
- Dianhua Qiao
- Department of Internal Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - Melissa Skibba
- Department of Internal Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - Xiaofang Xu
- Department of Internal Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - Roberto P Garofalo
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas
| | - Yingxin Zhao
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas
| | - Allan R Brasier
- Department of Internal Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin.,Institute for Clinical and Translational Research, University of Wisconsin-Madison, Madison, Wisconsin
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15
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Zaid Y, Doré É, Dubuc I, Archambault AS, Flamand O, Laviolette M, Flamand N, Boilard É, Flamand L. Chemokines and eicosanoids fuel the hyperinflammation within the lungs of patients with severe COVID-19. J Allergy Clin Immunol 2021; 148:368-380.e3. [PMID: 34111453 PMCID: PMC8180473 DOI: 10.1016/j.jaci.2021.05.032] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/10/2021] [Accepted: 05/19/2021] [Indexed: 02/06/2023]
Abstract
Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can lead to a variety of clinical outcomes, ranging from the absence of symptoms to severe acute respiratory disease and ultimately death. A feature of patients with severe coronavirus disease 2019 (COVID-19) is the abundance of inflammatory cytokines in the blood. Elevated levels of cytokines are predictive of infection severity and clinical outcome. In contrast, studies aimed at defining the driving forces behind the inflammation in lungs of subjects with severe COVID-19 remain scarce. Objective Our aim was to analyze and compare the plasma and bronchoalveolar lavage (BAL) fluids of patients with severe COVID-19 (n = 45) for the presence of cytokines and lipid mediators of inflammation (LMIs). Methods Cytokines were measured by using Luminex multiplex assay, and LMIs were measured by using liquid chromatography–tandem mass spectrometry. Results We revealed high concentrations of numerous cytokines, chemokines, and LMIs in the BAL fluid of patients with severe COVID-19. Of the 13 most abundant mediators in BAL fluid, 11 were chemokines, with CXCL1 and CXCL8 being 200 times more abundant than IL-6 and TNF-α. Eicosanoid levels were also elevated in the lungs of subjects with severe COVID-19. Consistent with the presence chemotactic molecules, BAL fluid samples were enriched for neutrophils, lymphocytes, and eosinophils. Inflammatory cytokines and LMIs in plasma showed limited correlations with those present in BAL fluid, arguing that circulating inflammatory molecules may not be a reliable proxy of the inflammation occurring in the lungs of patients with severe COVID-19. Conclusions Our findings indicate that hyperinflammation of the lungs of patients with severe COVID-19 is fueled by excessive production of chemokines and eicosanoids. Therapeutic strategies to dampen inflammation in patients with COVID-19 should be tailored accordingly.
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Affiliation(s)
- Younes Zaid
- Biology Department, Faculty of Sciences, Mohammed V University in Rabat, Morocco; Cheikh Zaïd Hospital, Abulcasis University of Health Sciences, Rabat, Morocco
| | - Étienne Doré
- Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du Centre Hospitalier Universitaire de Québec-Université Laval, Canada; Centre de Recherche Arthrite, Université Laval, Québec, Canada
| | - Isabelle Dubuc
- Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du Centre Hospitalier Universitaire de Québec-Université Laval, Canada
| | - Anne-Sophie Archambault
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Faculté de Médecine, Département de Médecine, Université Laval, Québec City, Québec, Canada; Canada Research Excellence Chair in the Microbiome-Endocannabinoidome Axis in Metabolic Health, Université Laval, Québec, Canada
| | - Olivier Flamand
- Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du Centre Hospitalier Universitaire de Québec-Université Laval, Canada
| | - Michel Laviolette
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Faculté de Médecine, Département de Médecine, Université Laval, Québec City, Québec, Canada
| | - Nicolas Flamand
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Faculté de Médecine, Département de Médecine, Université Laval, Québec City, Québec, Canada; Canada Research Excellence Chair in the Microbiome-Endocannabinoidome Axis in Metabolic Health, Université Laval, Québec, Canada
| | - Éric Boilard
- Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du Centre Hospitalier Universitaire de Québec-Université Laval, Canada; Centre de Recherche Arthrite, Université Laval, Québec, Canada; Département de Microbiologie-Infectiologie et d'Immunologie, Université Laval, Québec City, Canada
| | - Louis Flamand
- Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du Centre Hospitalier Universitaire de Québec-Université Laval, Canada; Département de Microbiologie-Infectiologie et d'Immunologie, Université Laval, Québec City, Canada.
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16
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Mann M, Brasier AR. Evolution of proteomics technologies for understanding respiratory syncytial virus pathogenesis. Expert Rev Proteomics 2021; 18:379-394. [PMID: 34018899 PMCID: PMC8277732 DOI: 10.1080/14789450.2021.1931130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 05/14/2021] [Indexed: 10/21/2022]
Abstract
Introduction: Respiratory syncytial virus (RSV) is a major human pathogen associated with long term morbidity. RSV replication occurs primarily in the epithelium, producing a complex cellular response associated with acute inflammation and long-lived changes in pulmonary function and allergic disease. Proteomics approaches provide important insights into post-transcriptional regulatory processes including alterations in cellular complexes regulating the coordinated innate response and epigenome.Areas covered: Peer-reviewed proteomics studies of host responses to RSV infections and proteomics techniques were analyzed. Methodologies identified include 1)." bottom-up" discovery proteomics, 2). Organellar proteomics by LC-gel fractionation; 3). Dynamic changes in protein interaction networks by LC-MS; and 4). selective reaction monitoring MS. We introduce recent developments in single-cell proteomics, top-down mass spectrometry, and photo-cleavable surfactant chemistries that will have impact on understanding how RSV induces extracellular matrix (ECM) composition and airway remodeling.Expert opinion: RSV replication induces global changes in the cellular proteome, dynamic shifts in nuclear proteins, and remodeling of epigenetic regulatory complexes linked to the innate response. Pathways discovered by proteomics technologies have led to deeper mechanistic understanding of the roles of heat shock proteins, redox response, transcriptional elongation complex remodeling and ECM secretion remodeling in host responses to RSV infections and pathological sequelae.
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Affiliation(s)
- Morgan Mann
- Department of Internal Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, USA
| | - Allan R Brasier
- Department of Internal Medicine and Institute for Clinical and Translational Research (ICTR), University of Wisconsin-Madison, Madison, WI, USA
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17
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Xu X, Qiao D, Dong C, Mann M, Garofalo RP, Keles S, Brasier AR. The SWI/SNF-Related, Matrix Associated, Actin-Dependent Regulator of Chromatin A4 Core Complex Represses Respiratory Syncytial Virus-Induced Syncytia Formation and Subepithelial Myofibroblast Transition. Front Immunol 2021; 12:633654. [PMID: 33732255 PMCID: PMC7957062 DOI: 10.3389/fimmu.2021.633654] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 01/18/2021] [Indexed: 12/15/2022] Open
Abstract
Epigenetics plays an important role in the priming the dynamic response of airway epithelial cells to infectious and environmental stressors. Here, we examine the epigenetic role of the SWI/SNF Related, Matrix Associated, Actin Dependent Regulator of Chromatin A4 (SMARCA4) in the epithelial response to RSV infection. Depletion of SMARCA4 destabilized the abundance of the SMARCE1/ARID1A SWI/SNF subunits, disrupting the innate response and triggering a hybrid epithelial/mesenchymal (E/M) state. Assaying SMARCA4 complex-regulated open chromatin domains by transposase cleavage -next generation sequencing (ATAC-Seq), we observed that the majority of cleavage sites in uninfected cells have reduced chromatin accessibility. Paradoxically, SMARCA4 complex-depleted cells showed enhanced RSV-inducible chromatin opening and gene expression in the EMT pathway genes, MMP9, SNAI1/2, VIM, and CDH2. Focusing on the key MMP9, we observed that SMARCA4 complex depletion reduced basal BRD4 and RNA Polymerase II binding, but enhanced BRD4/Pol II binding in response to RSV infection. In addition, we observed that MMP9 secretion in SMARCA4 complex deficient cells contributes to mesenchymal transition, cellular fusion (syncytia) and subepithelial myofibroblast transition. We conclude the SMARCA4 complex is a transcriptional repressor of epithelial plasticity, whose depletion triggers a hybrid E/M state that affects the dynamic response of the small airway epithelial cell in mucosal remodeling via paracrine MMP9 activity.
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Affiliation(s)
- Xiaofang Xu
- Department of Internal Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Dianhua Qiao
- Department of Internal Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Chenyang Dong
- Department of Statistics, University of Wisconsin-Madison, Madison, WI, United States
| | - Morgan Mann
- Department of Internal Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Roberto P. Garofalo
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX, United States
| | - Sunduz Keles
- Department of Statistics, University of Wisconsin-Madison, Madison, WI, United States
- Department of Biostatistics & Medical Informatics, University of Wisconsin-Madison, Madison, WI, United States
| | - Allan R. Brasier
- Department of Internal Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
- Institute for Clinical and Translational Research (ICTR), University of Wisconsin-Madison, Madison, WI, United States
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18
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Hofstetter AR, Sacco RE. Oxidative stress pathway gene transcription after bovine respiratory syncytial virus infection in vitro and ex vivo. Vet Immunol Immunopathol 2019; 219:109956. [PMID: 31706084 DOI: 10.1016/j.vetimm.2019.109956] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 09/24/2019] [Accepted: 09/30/2019] [Indexed: 11/26/2022]
Abstract
Studies in mouse and lamb models indicate important roles of reactive oxygen species (ROS) in the pathology and immune response to respiratory syncytial virus (RSV). The role of ROS in bovine RSV (BRSV) infection of calves remains unclear. BRSV naturally infects calves, leading to similar disease course, micro- and macro-lesions, and symptomology as is observed in RSV infection of human neonates. Furthermore, humans, lambs, and calves, but not mice, have an active lung oxidative system involving lactoperoxidase (LPO) and the dual oxidases (DUOX) 1 and 2. To gain insight into the role of ROS in the BRSV-infected lung, we examined gene expression in infected bovine cells using qPCR. A panel of 19 primers was used to assay ex vivo and in vitro BRSV-infected cells. The panel targeted genes involved in both production and regulation of ROS. BRSV infection significantly increased transcription of five genes in bovine respiratory tract cells in vitro and ex vivo. PTGS2 expression more than doubled in both sample types. Four transcripts varied significantly in lung lesions, but not non-lesion samples, compared with uninfected lung. This is the first report of the transcriptional profile of ROS-related genes in the airway after BRSV infection in the natural host.
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Affiliation(s)
- Amelia R Hofstetter
- Ruminant Diseases and Immunology Research Unit, National Animal Disease Center, United States Department of Agriculture, 1920 Dayton Avenue, Ames, IA, 50010, United States of America.
| | - Randy E Sacco
- Ruminant Diseases and Immunology Research Unit, National Animal Disease Center, United States Department of Agriculture, 1920 Dayton Avenue, Ames, IA, 50010, United States of America.
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19
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Rayavara K, Kurosky A, Stafford SJ, Garg NJ, Brasier AR, Garofalo RP, Hosakote YM. Proinflammatory Effects of Respiratory Syncytial Virus-Induced Epithelial HMGB1 on Human Innate Immune Cell Activation. THE JOURNAL OF IMMUNOLOGY 2018; 201:2753-2766. [PMID: 30275049 DOI: 10.4049/jimmunol.1800558] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 08/29/2018] [Indexed: 01/21/2023]
Abstract
High mobility group box 1 (HMGB1) is a multifunctional nuclear protein that translocates to the cytoplasm and is subsequently released to the extracellular space during infection and injury. Once released, it acts as a damage-associated molecular pattern and regulates immune and inflammatory responses. Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory tract infections in infants and elderly, for which no effective treatment or vaccine is currently available. This study investigated the effects of HMGB1 on cytokine secretion, as well as the involvement of NF-κB and TLR4 pathways in RSV-induced HMGB1 release in human airway epithelial cells (AECs) and its proinflammatory effects on several human primary immune cells. Purified HMGB1 was incubated with AECs (A549 and small alveolar epithelial cells) and various immune cells and measured the release of proinflammatory mediators and the activation of NF-κB and P38 MAPK. HMGB1 treatment significantly increased the phosphorylation of NF-κB and P38 MAPK but did not induce the release of cytokines/chemokines from AECs. However, addition of HMGB1 to immune cells did significantly induce the release of cytokines/chemokines and activated the NF-κB and P38 MAPK pathways. We found that activation of NF-κB accounted for RSV-induced HMGB1 secretion in AECs in a TLR4-dependent manner. These results indicated that HMGB1 secreted from AECs can facilitate the secretion of proinflammatory mediators from immune cells in a paracrine mechanism, thus promoting the inflammatory response that contributes to RSV pathogenesis. Therefore, blocking the proinflammatory function of HMGB1 may be an effective approach for developing novel therapeutics.
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Affiliation(s)
- Kempaiah Rayavara
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77555
| | - Alexander Kurosky
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX 77555
| | - Susan J Stafford
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX 77555
| | - Nisha J Garg
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77555
| | - Allan R Brasier
- Division of Endocrinology, Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX 77555.,Institute for Translational Sciences, The University of Texas Medical Branch, Galveston, TX 77555
| | - Roberto P Garofalo
- Department of Pediatrics, The University of Texas Medical Branch, Galveston, TX 77555; and.,Sealy Center for Vaccine Development, The University of Texas Medical Branch, Galveston, TX 77555
| | - Yashoda M Hosakote
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77555; .,Institute for Translational Sciences, The University of Texas Medical Branch, Galveston, TX 77555
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20
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Central Role of the NF-κB Pathway in the Scgb1a1-Expressing Epithelium in Mediating Respiratory Syncytial Virus-Induced Airway Inflammation. J Virol 2018; 92:JVI.00441-18. [PMID: 29593031 DOI: 10.1128/jvi.00441-18] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 03/20/2018] [Indexed: 12/24/2022] Open
Abstract
Lower respiratory tract infection with respiratory syncytial virus (RSV) produces profound inflammation. Despite an understanding of the role of adaptive immunity in RSV infection, the identity of the major sentinel cells initially triggering inflammation is controversial. Here we evaluate the role of nonciliated secretoglobin (Scgb1a1)-expressing bronchiolar epithelial cells in RSV infection. Mice expressing a tamoxifen (TMX)-inducible Cre recombinase-estrogen receptor fusion protein (CreERTM) knocked into the Scgb1a1 locus were crossed with mice that harbor a RelA conditional allele (RelAfl ), with loxP sites flanking exons 5 to 8 of the Rel homology domain. The Scgb1a1CreERTM/+ × RelAfl/fl mouse is a RelA conditional knockout (RelACKO) of a nonciliated epithelial cell population enriched in the small bronchioles. TMX-treated RelACKO mice have reduced pulmonary neutrophilic infiltration and impaired expression and secretion of NF-κB-dependent cytokines in response to RSV. In addition, RelACKO mice had reduced expression levels of interferon (IFN) regulatory factor 1/7 (IRF1/7) and retinoic acid-inducible gene I (RIG-I), components of the mucosal IFN positive-feedback loop. We demonstrate that RSV replication induces RelA to complex with bromodomain-containing protein 4 (BRD4), a cofactor required for RNA polymerase II (Pol II) phosphorylation, activating the atypical histone acetyltransferase (HAT) activity of BRD4 required for phospho-Ser2 Pol II formation, histone H3K122 acetylation, and cytokine secretion in vitro and in vivo TMX-treated RelACKO mice have less weight loss and reduced airway obstruction/hyperreactivity yet similar levels of IFN-γ production despite higher levels of virus production. These data indicate that the nonciliated Scgb1a1-expressing epithelium is a major innate sensor for restricting RSV infection by mediating neutrophilic inflammation and chemokine and mucosal IFN production via the RelA-BRD4 pathway.IMPORTANCE RSV infection is the most common cause of infant hospitalizations in the United States, resulting in 2.1 million children annually requiring medical attention. RSV primarily infects nasal epithelial cells, spreading distally to produce severe lower respiratory tract infections. Our study examines the role of a nonciliated respiratory epithelial cell population in RSV infection. We genetically engineered a mouse that can be selectively depleted of the NF-κB/RelA transcription factor in this subset of epithelial cells. These mice show an impaired activation of the bromodomain-containing protein 4 (BRD4) coactivator, resulting in reduced cytokine expression and neutrophilic inflammation. During the course of RSV infection, epithelial RelA-depleted mice have reduced disease scores and airway hyperreactivity yet increased levels of virus replication. We conclude that RelA-BRD4 signaling in nonciliated bronchiolar epithelial cells mediates neutrophilic airway inflammation and disease severity. This complex is an attractive target to reduce the severity of infection.
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21
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Wark PAB, Ramsahai JM, Pathinayake P, Malik B, Bartlett NW. Respiratory Viruses and Asthma. Semin Respir Crit Care Med 2018; 39:45-55. [PMID: 29427985 PMCID: PMC7117086 DOI: 10.1055/s-0037-1617412] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Asthma remains the most prevalent chronic respiratory disorder, affecting people of all ages. The relationship between respiratory virus infection and asthma has long been recognized, though remains incompletely understood. In this article, we will address key issues around this relationship. These will include the crucial role virus infection plays in early life, as a potential risk factor for the development of asthma and lung disease. We will assess the impact that virus infection has on those with established asthma as a trigger for acute disease and how this may influence asthma throughout life. Finally, we will explore the complex interaction that occurs between the airway and the immune responses that make those with asthma so susceptible to the effects of virus infection.
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Affiliation(s)
- Peter A B Wark
- Centre for Healthy Lungs, Hunter Medical Research Institute, The University of Newcastle, New South Wales, Australia.,Department of Respiratory and Sleep Medicine, John Hunter Hospital, New South Wales, Australia
| | - James Michael Ramsahai
- Centre for Healthy Lungs, Hunter Medical Research Institute, The University of Newcastle, New South Wales, Australia.,Department of Respiratory and Sleep Medicine, John Hunter Hospital, New South Wales, Australia
| | - Prabuddha Pathinayake
- Centre for Healthy Lungs, Hunter Medical Research Institute, The University of Newcastle, New South Wales, Australia.,Department of Respiratory and Sleep Medicine, John Hunter Hospital, New South Wales, Australia
| | - Bilal Malik
- Centre for Healthy Lungs, Hunter Medical Research Institute, The University of Newcastle, New South Wales, Australia
| | - Nathan W Bartlett
- Centre for Healthy Lungs, Hunter Medical Research Institute, The University of Newcastle, New South Wales, Australia.,School of Biomedical Sciences, The University of Newcastle, New South Wales, Australia
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Tian B, Yang J, Zhao Y, Ivanciuc T, Sun H, Garofalo RP, Brasier AR. BRD4 Couples NF-κB/RelA with Airway Inflammation and the IRF-RIG-I Amplification Loop in Respiratory Syncytial Virus Infection. J Virol 2017; 91:e00007-17. [PMID: 28077651 PMCID: PMC5331805 DOI: 10.1128/jvi.00007-17] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 01/04/2017] [Indexed: 01/09/2023] Open
Abstract
The airway mucosa expresses protective interferon (IFN) and inflammatory cytokines in response to respiratory syncytial virus (RSV) infection. In this study, we examine the role of bromodomain containing 4 (BRD4) in mediating this innate immune response in human small airway epithelial cells. We observe that RSV induces BRD4 to complex with NF-κB/RelA. BRD4 is functionally required for expression of the NF-κB-dependent inflammatory gene regulatory network (GRN), including the IFN response factor 1 (IRF1) and IRF7, which mediate a cross talk pathway for RIG-I upregulation. Mechanistically, BRD4 is required for cyclin-dependent kinase 9 (CDK9) recruitment and phospho-Ser 2 carboxy-terminal domain (CTD) RNA polymerase (Pol) II formation on the promoters of IRF1, IRF7, and RIG-I, producing their enhanced expression by transcriptional elongation. We also find that BRD4 independently regulates CDK9/phospho-Ser 2 CTD RNA Pol II recruitment to the IRF3-dependent IFN-stimulated genes (ISGs). In vivo, poly(I·C)-induced neutrophilia and mucosal chemokine production are blocked by a small-molecule BRD4 bromodomain inhibitor. Similarly, BRD4 inhibition reduces RSV-induced neutrophilia, mucosal CXC chemokine expression, activation of the IRF7-RIG-I autoamplification loop, mucosal IFN expression, and airway obstruction. RSV infection activates BRD4 acetyltransferase activity on histone H3 Lys (K) 122, demonstrating that RSV infection activates BRD4 in vivo These data validate BRD4 as a major effector of RSV-induced inflammation and disease. BRD4 is required for coupling NF-κB to expression of inflammatory genes and the IRF-RIG-I autoamplification pathway and independently facilitates antiviral ISG expression. BRD4 inhibition may be a strategy to reduce exuberant virus-induced mucosal airway inflammation.IMPORTANCE In the United States, 2.1 million children annually require medical attention for RSV infections. A first line of defense is the expression of the innate gene network by infected epithelial cells. Expression of the innate response requires the recruitment of transcriptional elongation factors to rapidly induce innate response genes through an unknown mechanism. We discovered that RSV infection induces a complex of bromodomain containing 4 (BRD4) with NF-κB and cyclin-dependent kinase 9 (CDK9). BRD4 is required for stable CDK9 binding, phospho-Ser 2 RNA Pol II formation, and histone acetyltransferase activity. Inhibition of BRD4 blocks Toll-like receptor 3 (TLR3)-dependent neutrophilia and RSV-induced inflammation, demonstrating its importance in the mucosal innate response in vivo Our study shows that BRD4 plays a central role in inflammation and activation of the IRF7-RIG-I amplification loop vital for mucosal interferon expression. BRD4 inhibition may be a strategy for modulating exuberant mucosal airway inflammation.
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Affiliation(s)
- Bing Tian
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA
- Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas, USA
| | - Jun Yang
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA
- Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas, USA
| | - Yingxin Zhao
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA
- Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas, USA
- Institute for Translational Sciences, University of Texas Medical Branch, Galveston, Texas, USA
| | - Teodora Ivanciuc
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas, USA
| | - Hong Sun
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA
| | - Roberto P Garofalo
- Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas, USA
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas, USA
| | - Allan R Brasier
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA
- Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas, USA
- Institute for Translational Sciences, University of Texas Medical Branch, Galveston, Texas, USA
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23
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Ogra PL, Barenkamp SJ, DeMaria TF, Bakaletz LO, Chonmaitree T, Heikkinen T, Hurst DS, Kawauchi H, Kurono Y, Patel JA, Sih TM, Stenfors LE, Suzuki M. 6. Microbiology and Immunology. Ann Otol Rhinol Laryngol 2016. [DOI: 10.1177/00034894021110s309] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Respiratory Syncytial Virus Infection Triggers Epithelial HMGB1 Release as a Damage-Associated Molecular Pattern Promoting a Monocytic Inflammatory Response. J Virol 2016; 90:9618-9631. [PMID: 27535058 DOI: 10.1128/jvi.01279-16] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 08/03/2016] [Indexed: 12/18/2022] Open
Abstract
Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infant and elderly populations worldwide. Currently, there is no efficacious vaccine or therapy available for RSV infection. The molecular mechanisms underlying RSV-induced acute airway disease and associated long-term consequences remain largely unknown; however, experimental evidence suggests that the lung inflammatory response plays a fundamental role in the outcome of RSV infection. High-mobility group box 1 (HMGB1) is a nuclear protein that triggers inflammation when released from activated immune or necrotic cells and drives the pathogenesis of various infectious agents. Although HMGB1 has been implicated in many inflammatory diseases, its role in RSV-induced airway inflammation has not been investigated. This study investigates the molecular mechanism of action of extracellularly released HMGB1 in airway epithelial cells (A549 and small airway epithelial cells) to establish its role in RSV infection. Immunofluorescence microscopy and Western blotting results showed that RSV infection of human airway epithelial cells induced a significant release of HMGB1 as a result of translocation of HMGB1 from the cell nuclei to the cytoplasm and subsequent release into the extracellular space. Treating RSV-infected A549 cells with antioxidants significantly inhibited RSV-induced HMGB1 extracellular release. Studies using recombinant HMGB1 triggered immune responses by activating primary human monocytes. Finally, HMGB1 released by airway epithelial cells due to RSV infection appears to function as a paracrine factor priming epithelial cells and monocytes to inflammatory stimuli in the airways. IMPORTANCE RSV is a major cause of serious lower respiratory tract infections in young children and causes severe respiratory morbidity and mortality in the elderly. In addition, to date there is no effective treatment or vaccine available for RSV infection. The mechanisms responsible for RSV-induced acute airway disease and associated long-term consequences remain largely unknown. The oxidative stress response in the airways plays a major role in the pathogenesis of RSV. HMGB1 is a ubiquitous redox-sensitive multifunctional protein that serves as both a DNA regulatory protein and an extracellular cytokine signaling molecule that promotes airway inflammation as a damage-associated molecular pattern. This study investigated the mechanism of action of HMGB1 in RSV infection with the aim of identifying new inflammatory pathways at the molecular level that may be amenable to therapeutic interventions.
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Chen Y, Deng X, Deng J, Zhou J, Ren Y, Liu S, Prusak DJ, Wood TG, Bao X. Functional motifs responsible for human metapneumovirus M2-2-mediated innate immune evasion. Virology 2016; 499:361-368. [PMID: 27743962 PMCID: PMC5102771 DOI: 10.1016/j.virol.2016.09.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 09/23/2016] [Accepted: 09/26/2016] [Indexed: 01/12/2023]
Abstract
Human metapneumovirus (hMPV) is a major cause of lower respiratory infection in young children. Repeated infections occur throughout life, but its immune evasion mechanisms are largely unknown. We recently found that hMPV M2-2 protein elicits immune evasion by targeting mitochondrial antiviral-signaling protein (MAVS), an antiviral signaling molecule. However, the molecular mechanisms underlying such inhibition are not known. Our mutagenesis studies revealed that PDZ-binding motifs, 29-DEMI-32 and 39-KEALSDGI-46, located in an immune inhibitory region of M2-2, are responsible for M2-2-mediated immune evasion. We also found both motifs prevent TRAF5 and TRAF6, the MAVS downstream adaptors, to be recruited to MAVS, while the motif 39-KEALSDGI-46 also blocks TRAF3 migrating to MAVS. In parallel, these TRAFs are important in activating transcription factors NF-kB and/or IRF-3 by hMPV. Our findings collectively demonstrate that M2-2 uses its PDZ motifs to launch the hMPV immune evasion through blocking the interaction of MAVS and its downstream TRAFs. This manuscript describes a molecular mechanism underlying the immune evasion of hMPV. Results create the design basis for safer and more effective hMPV vaccines/therapeutic molecules. We demonstrate the contribution of TRAFs in antiviral responses to hMPV infection.
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Affiliation(s)
- Yu Chen
- Department of Pediatrics, TongJi Hospital, TongJi Medical College, Huazhong University of Science and Technology, China; Department of Pediatrics, University of Texas Medical Branch, Galveston, TX, United States
| | - Xiaoling Deng
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX, United States
| | - Junfang Deng
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX, United States; Department of Hepatobiliary Surgery, The First Affiliated Hospital, College of Medicine, Zhejiang University, China
| | - Jiehua Zhou
- Department of Pediatrics, TongJi Hospital, TongJi Medical College, Huazhong University of Science and Technology, China
| | - Yuping Ren
- Department of Pediatrics, TongJi Hospital, TongJi Medical College, Huazhong University of Science and Technology, China; Department of Pediatrics, University of Texas Medical Branch, Galveston, TX, United States
| | - Shengxuan Liu
- Department of Pediatrics, TongJi Hospital, TongJi Medical College, Huazhong University of Science and Technology, China; Department of Pediatrics, University of Texas Medical Branch, Galveston, TX, United States
| | - Deborah J Prusak
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, United States; Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - Thomas G Wood
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, United States; Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - Xiaoyong Bao
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX, United States; Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, TX, United States; The Institute of Translational Science, University of Texas Medical Branch, Galveston, TX, United States; The Institute for Human Infections & Immunity, University of Texas Medical Branch, Galveston, TX, United States.
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26
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RIPK4 activates an IRF6-mediated proinflammatory cytokine response in keratinocytes. Cytokine 2016; 83:19-26. [DOI: 10.1016/j.cyto.2016.03.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 03/08/2016] [Accepted: 03/08/2016] [Indexed: 12/12/2022]
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Volatile oils: Potential agents for the treatment of respiratory infections. THE MICROBIOLOGY OF RESPIRATORY SYSTEM INFECTIONS 2016. [PMCID: PMC7149900 DOI: 10.1016/b978-0-12-804543-5.00016-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Due to presence of secondary bioactive metabolites, natural compounds are considered a major source of new active molecules that can be developed as new drugs. Infectious diseases, and mainly the common respiratory infections, are major challenges to the current chemotherapy systems and, therefore, there is a requirement to find new compounds with therapeutic potential. The volatile natural compounds and essential oils are the main treasure agents in the natural compounds with antibiotic potential. The present chapter reviews natural traditional remedies used in the treatment of respiratory infections with the emphasis on antibacterial, antiviral, and antiinflammation activities of the volatile natural compounds (essential oils, etc.), and provides a brief view in some of structural activity relationships between antibacterial potencies and chemical structures of the essential oil’s constituents.
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28
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Escaffre O, Halliday H, Borisevich V, Casola A, Rockx B. Oxidative stress in Nipah virus-infected human small airway epithelial cells. J Gen Virol 2015; 96:2961-2970. [PMID: 26297489 DOI: 10.1099/jgv.0.000243] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Nipah virus (NiV) is a zoonotic emerging pathogen that can cause severe and often fatal respiratory disease in humans. The pathogenesis of NiV infection of the human respiratory tract remains unknown. Reactive oxygen species (ROS) produced by airway epithelial cells in response to viral infections contribute to lung injury by inducing inflammation and oxidative stress; however, the role of ROS in NiV-induced respiratory disease is unknown. To investigate whether NiV induces oxidative stress in human respiratory epithelial cells, we used oxidative stress markers and monitored antioxidant gene expression. We also used ROS scavengers to assess their role in immune response modulation. Oxidative stress was confirmed in infected cells and correlated with the reduction in antioxidant enzyme gene expression. Infected cells treated by ROS scavengers resulted in a significant decrease of the (F2)-8-isoprostane marker, inflammatory responses and virus replication. In conclusion, ROS are induced during NiV infection in human respiratory epithelium and contribute to the inflammatory response. Understanding how oxidative stress contributes to NiV pathogenesis is crucial for therapeutic development.
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Affiliation(s)
- Olivier Escaffre
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
| | - Hailey Halliday
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
| | | | - Antonella Casola
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX, USA.,Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA
| | - Barry Rockx
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA.,Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA.,Department of Rare and Emerging Viral Infections and Response, Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
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29
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Thompson TM, Roddam PL, Harrison LM, Aitken JA, DeVincenzo JP. Viral Specific Factors Contribute to Clinical Respiratory Syncytial Virus Disease Severity Differences in Infants. ACTA ACUST UNITED AC 2015; 4. [PMID: 26473163 PMCID: PMC4603536 DOI: 10.4172/2327-5073.1000206] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Background There is a wide range of severity of respiratory syncytial viral (RSV) disease in previously healthy infants. Host factors have been well demonstrated to contribute to disease severity differences. However the possibility of disease severity differences being produced by factors intrinsic to the virus itself has rarely been studied. Methods Low-passage isolates of RSV collected prospectively from infants with different degrees of RSV disease severity were evaluated in vitro, holding host factors constant, so as to assess whether isolates induced phenotypically different cytokine/chemokine concentrations in a human lung epithelial cell line. Sixty-seven RSV isolates from previously healthy infants (38 hospitalized for acute RSV infection (severe disease) and 29 never requiring hospitalization (mild disease)) were inoculated into A549, lung epithelial cells at precisely controlled, low multiplicity of infection to mimic natural infection. Cultures were evaluated at 48 hours, 60 hours, and 72 hours to evaluate area under the curve (AUC) cytokine/chemokine induction. Results Cells infected with isolates from severely ill infants produced higher mean concentrations of all cytokine/chemokines tested (IL-1α, IL-6, IL-8 and RANTES) at all-time points tested. RSV isolates collected from infants with severe disease induced significantly higher AUCIL-8 and AUCRANTES secretion in infected cultures than mild disease isolates (p=0.028 and p=0.019 respectively). IL-8 and RANTES concentrations were 4 times higher at 48 hours for these severely ill infant isolates. Additionally, 38 isolates were evaluated at all-time points for quantity of virus. RSV concentration significantly correlated with both IL-8 and RANTES at all-time points. Neither cytokine/chemokine concentrations nor RSV concentrations were associated with RSV subgroup. Discussion Infants’ RSV disease severity differences may be due in part to intrinsic viral strain-specific characteristics.
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Affiliation(s)
- Tonya M Thompson
- University of Tennessee School of Medicine, Department of Pediatrics ; University of Arkansas for Medical Sciences, Department of Pediatric Emergency Medicine, Little Rock, AR 72202
| | - Philippa L Roddam
- University of Tennessee School of Medicine, Department of Pediatrics ; Le Bonheur Children's Hospital ; The Children's Foundation Research Institute at Le Bonheur Children's Hospital, Memphis, TN 38103
| | - Lisa M Harrison
- University of Tennessee School of Medicine, Department of Pediatrics ; Le Bonheur Children's Hospital ; The Children's Foundation Research Institute at Le Bonheur Children's Hospital, Memphis, TN 38103
| | - Jody A Aitken
- University of Tennessee School of Medicine, Department of Pediatrics ; Le Bonheur Children's Hospital ; The Children's Foundation Research Institute at Le Bonheur Children's Hospital, Memphis, TN 38103
| | - John P DeVincenzo
- University of Tennessee School of Medicine, Department of Pediatrics ; University of Tennessee Graduate School of Health Sciences, Department of Molecular Sciences ; Le Bonheur Children's Hospital ; The Children's Foundation Research Institute at Le Bonheur Children's Hospital, Memphis, TN 38103
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30
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Ashbrook MJ, McDonough KL, Pituch JJ, Christopherson PL, Cornell TT, Selewski DT, Shanley TP, Blatt NB. Citrate modulates lipopolysaccharide-induced monocyte inflammatory responses. Clin Exp Immunol 2015; 180:520-30. [PMID: 25619261 DOI: 10.1111/cei.12591] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2015] [Indexed: 12/25/2022] Open
Abstract
Citrate, a central component of cellular metabolism, is a widely used anti-coagulant due to its ability to chelate calcium. Adenosine triphosphate (ATP)-citrate lyase, which metabolizes citrate, has been shown to be essential for inflammation, but the ability of exogenous citrate to impact inflammatory signalling cascades remains largely unknown. We hypothesized that citrate would modulate inflammatory responses as both a cellular metabolite and calcium chelator, and tested this hypothesis by determining how clinically relevant levels of citrate modulate monocyte proinflammatory responses to lipopolysaccharide (LPS) in a human acute monocytic leukaemia cell line (THP-1). In normal medium (0.4 mM calcium), citrate inhibited LPS-induced tumour necrosis factor (TNF)-α and interleukin (IL)-8 transcripts, whereas in medium supplemented with calcium (1.4 mM), TNF-α and IL-8 levels increased and appeared independent of calcium chelation. Using an IL-8-luciferase plasmid construct, the same increased response was observed in the activation of the IL-8 promoter region, suggesting transcriptional regulation. Tricarballylic acid, an inhibitor of ATP-citrate lyase, blocked the ability of citrate to augment TNF-α, linking citrate's augmentation effect with its metabolism by ATP-citrate lyase. In the presence of citrate, increased histone acetylation was observed in the TNF-α and IL-8 promoter regions of THP-1 cells. We observed that citrate can both augment and inhibit proinflammatory cytokine production via modulation of inflammatory gene transactivation. These findings suggest that citrate anti-coagulation may alter immune function through complex interactions with the inflammatory response.
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Affiliation(s)
- M J Ashbrook
- Divisions of Pediatric Nephrology, University of Michigan, Ann Arbor, MI, USA
| | - K L McDonough
- Pediatric Critical Care, Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI, USA
| | - J J Pituch
- Divisions of Pediatric Nephrology, University of Michigan, Ann Arbor, MI, USA
| | - P L Christopherson
- Divisions of Pediatric Nephrology, University of Michigan, Ann Arbor, MI, USA
| | - T T Cornell
- Pediatric Critical Care, Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI, USA
| | - D T Selewski
- Divisions of Pediatric Nephrology, University of Michigan, Ann Arbor, MI, USA
| | - T P Shanley
- Pediatric Critical Care, Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI, USA
| | - N B Blatt
- Divisions of Pediatric Nephrology, University of Michigan, Ann Arbor, MI, USA
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Role of hydrogen sulfide in paramyxovirus infections. J Virol 2015; 89:5557-68. [PMID: 25740991 DOI: 10.1128/jvi.00264-15] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 02/27/2015] [Indexed: 12/11/2022] Open
Abstract
UNLABELLED Hydrogen sulfide (H2S) is an endogenous gaseous mediator that has gained increasing recognition as an important player in modulating acute and chronic inflammatory diseases. However, its role in virus-induced lung inflammation is currently unknown. Respiratory syncytial virus (RSV) is a major cause of upper and lower respiratory tract infections in children for which no vaccine or effective treatment is available. Using the slow-releasing H2S donor GYY4137 and propargylglycin (PAG), an inhibitor of cystathionine-γ-lyase (CSE), a key enzyme that produces intracellular H2S, we found that RSV infection led to a reduced ability to generate and maintain intracellular H2S levels in airway epithelial cells (AECs). Inhibition of CSE with PAG resulted in increased viral replication and chemokine secretion. On the other hand, treatment of AECs with the H2S donor GYY4137 reduced proinflammatory mediator production and significantly reduced viral replication, even when administered several hours after viral absorption. GYY4137 also significantly reduced replication and inflammatory chemokine production induced by human metapneumovirus (hMPV) and Nipah virus (NiV), suggesting a broad inhibitory effect of H2S on paramyxovirus infections. GYY4137 treatment had no effect on RSV genome replication or viral mRNA and protein synthesis, but it inhibited syncytium formation and virus assembly/release. GYY4137 inhibition of proinflammatory gene expression occurred by modulation of the activation of the key transcription factors nuclear factor κB (NF-κB) and interferon regulatory factor 3 (IRF-3) at a step subsequent to their nuclear translocation. H2S antiviral and immunoregulatory properties could represent a novel treatment strategy for paramyxovirus infections. IMPORTANCE RSV is a global health concern, causing significant morbidity and economic losses as well as mortality in developing countries. After decades of intensive research, no vaccine or effective treatment, with the exception of immunoprophylaxis, is available for this infection as well as for other important respiratory mucosal viruses. This study identifies hydrogen sulfide as a novel cellular mediator that can modulate viral replication and proinflammatory gene expression, both important determinants of lung injury in respiratory viral infections, with potential for rapid translation of such findings into novel therapeutic approaches for viral bronchiolitis and pneumonia.
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Fang L, Choudhary S, Tian B, Boldogh I, Yang C, Ivanciuc T, Ma Y, Garofalo RP, Brasier AR. Ataxia telangiectasia mutated kinase mediates NF-κB serine 276 phosphorylation and interferon expression via the IRF7-RIG-I amplification loop in paramyxovirus infection. J Virol 2015; 89:2628-42. [PMID: 25520509 PMCID: PMC4325710 DOI: 10.1128/jvi.02458-14] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 12/09/2014] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Respiratory syncytial virus (RSV) is a primary etiological agent of childhood lower respiratory tract disease. Molecular patterns induced by active infection trigger a coordinated retinoic acid-inducible gene I (RIG-I)-Toll-like receptor (TLR) signaling response to induce inflammatory cytokines and antiviral mucosal interferons. Recently, we discovered a nuclear oxidative stress-sensitive pathway mediated by the DNA damage response protein, ataxia telangiectasia mutated (ATM), in cytokine-induced NF-κB/RelA Ser 276 phosphorylation. Here we observe that ATM silencing results in enhanced single-strand RNA (ssRNA) replication of RSVand Sendai virus, due to decreased expression and secretion of type I and III interferons (IFNs), despite maintenance of IFN regulatory factor 3 (IRF3)-dependent IFN-stimulated genes (ISGs). In addition to enhanced oxidative stress, RSV replication enhances foci of phosphorylated histone 2AX variant (γH2AX), Ser 1981 phosphorylation of ATM, and IKKγ/NEMO-dependent ATM nuclear export, indicating activation of the DNA damage response. ATM-deficient cells show defective RSV-induced mitogen and stress-activated kinase 1 (MSK-1) Ser 376 phosphorylation and reduced RelA Ser 276 phosphorylation, whose formation is required for IRF7 expression. We observe that RelA inducibly binds the native IFN regulatory factor 7 (IRF7) promoter in an ATM-dependent manner, and IRF7 inducibly binds to the endogenous retinoic acid-inducible gene I (RIG-I) promoter. Ectopic IRF7 expression restores RIG-I expression and type I/III IFN expression in ATM-silenced cells. We conclude that paramyxoviruses trigger the DNA damage response, a pathway required for MSK1 activation of phospho Ser 276 RelA formation to trigger the IRF7-RIG-I amplification loop necessary for mucosal IFN production. These data provide the molecular pathogenesis for defects in the cellular innate immunity of patients with homozygous ATM mutations. IMPORTANCE RNA virus infections trigger cellular response pathways to limit spread to adjacent tissues. This "innate immune response" is mediated by germ line-encoded pattern recognition receptors that trigger activation of two, largely independent, intracellular NF-κB and IRF3 transcription factors. Downstream, expression of protective antiviral interferons is amplified by positive-feedback loops mediated by inducible interferon regulatory factors (IRFs) and retinoic acid inducible gene (RIG-I). Our results indicate that a nuclear oxidative stress- and DNA damage-sensing factor, ATM, is required to mediate a cross talk pathway between NF-κB and IRF7 through mediating phosphorylation of NF-κB. Our studies provide further information about the defects in cellular and innate immunity in patients with inherited ATM mutations.
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Affiliation(s)
- Ling Fang
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Sanjeev Choudhary
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas, USA Institute for Translational Sciences, University of Texas Medical Branch, Galveston, Texas, USA
| | - Bing Tian
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas, USA Institute for Translational Sciences, University of Texas Medical Branch, Galveston, Texas, USA
| | - Istvan Boldogh
- Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas, USA Institute for Translational Sciences, University of Texas Medical Branch, Galveston, Texas, USA Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Chunying Yang
- Department of Radiation Oncology, Houston Methodist Research Institute, Weill Cornell University, Houston, Texas, USA
| | - Teodora Ivanciuc
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas, USA
| | - Yinghong Ma
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas, USA
| | - Roberto P Garofalo
- Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas, USA Institute for Translational Sciences, University of Texas Medical Branch, Galveston, Texas, USA Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas, USA
| | - Allan R Brasier
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas, USA Institute for Translational Sciences, University of Texas Medical Branch, Galveston, Texas, USA
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Abstract
Acute respiratory tract infection (RTI) is a leading cause of morbidity and mortality worldwide and the majority of RTIs are caused by viruses, among which respiratory syncytial virus (RSV) and the closely related human metapneumovirus (hMPV) figure prominently. Host innate immune response has been implicated in recognition, protection and immune pathological mechanisms. Host-viral interactions are generally initiated via host recognition of pathogen-associated molecular patterns (PAMPs) of the virus. This recognition occurs through host pattern recognition receptors (PRRs) which are expressed on innate immune cells such as epithelial cells, dendritic cells, macrophages and neutrophils. Multiple PRR families, including Toll-like receptors (TLRs), RIG-I-like receptors (RLRs) and NOD-like receptors (NLRs), contribute significantly to viral detection, leading to induction of cytokines, chemokines and type I interferons (IFNs), which subsequently facilitate the eradication of the virus. This review focuses on the current literature on RSV and hMPV infection and the role of PRRs in establishing/mediating the infection in both in vitro and in vivo models. A better understanding of the complex interplay between these two viruses and host PRRs might lead to efficient prophylactic and therapeutic treatments, as well as the development of adequate vaccines.
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Parainfluenza virus type 1 induces epithelial IL-8 production via p38-MAPK signalling. J Immunol Res 2014; 2014:515984. [PMID: 25013817 PMCID: PMC4072021 DOI: 10.1155/2014/515984] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 05/11/2014] [Accepted: 05/23/2014] [Indexed: 12/13/2022] Open
Abstract
Human parainfluenza virus type 1 (HPIV-1) is the most common cause of croup in infants. The aim of this study was to describe molecular mechanisms associated with IL-8 production during HPIV-1 infection and the role of viral replication in MAPK synthesis and activation. An in vitro model of HPIV-1 infection in the HEp-2 and A549 cell lines was used; a kinetic-based ELISA for IL-8 detection was also used, phosphorylation of the mitogen-activated protein kinases (MAPKs) was identified by Western blot analysis, and specific inhibitors for each kinase were used to identify which MAPK was involved. Inactivated viruses were used to assess whether viral replication is required for IL-8 production. Results revealed a gradual increase in IL-8 production at different selected times, when phosphorylation of MAPK was detected. The secretion of IL-8 in the two cell lines infected with the HPIV-1 is related to the phosphorylation of the MAPK as well as viral replication. Inhibition of p38 suppressed the secretion of IL-8 in the HEp-2 cells. No kinase activation was observed when viruses were inactivated.
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Kwa MQ, Nguyen T, Huynh J, Ramnath D, De Nardo D, Lam PY, Reynolds EC, Hamilton JA, Sweet MJ, Scholz GM. Interferon regulatory factor 6 differentially regulates Toll-like receptor 2-dependent chemokine gene expression in epithelial cells. J Biol Chem 2014; 289:19758-68. [PMID: 24872416 DOI: 10.1074/jbc.m114.584540] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Epidermal and mucosal epithelial cells are integral to host defense. They not only act as a physical barrier but also utilize pattern recognition receptors, such as the Toll-like receptors (TLRs), to detect and respond to pathogens. Members of the interferon regulatory factor (IRF) family of transcription factors are key components of TLR signaling as they impart specificity to downstream responses. Although IRF6 is a critical regulator of epithelial cell proliferation and differentiation, its role in TLR signaling has not previously been addressed. We show here that IRF6 is activated by IRAK1 as well as by MyD88 but not by TRIF or TBK1. Co-immunoprecipitation experiments further demonstrated that IRF6 can interact with IRAK1. Gene silencing in epithelial cells along with gene promoter reporter assays showed that IRAK1 mediates TLR2-inducible CCL5 gene expression at least in part by promoting IRF6 activation. Conversely, IRAK1 regulated CXCL8 gene expression independently of IRF6, thus identifying a molecular mechanism by which TLR2 signaling differentially regulates the expression of specific chemokines in epithelial cells. Bioinformatics analysis and mutagenesis-based experiments identified Ser-413 and Ser-424 as key regulatory sites in IRF6. Phosphomimetic mutation of these residues resulted in greatly enhanced IRF6 dimerization and trans-activator function. Collectively, our findings suggest that, in addition to its importance for epithelial barrier function, IRF6 also contributes to host defense by providing specificity to the regulation of inflammatory chemokine expression by TLR2 in epithelial cells.
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Affiliation(s)
- Mei Qi Kwa
- From the Oral Health Cooperative Research Centre, Melbourne Dental School, and Bio21 Institute, and Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3010, Australia, and
| | - Thao Nguyen
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3010, Australia, and
| | - Jennifer Huynh
- From the Oral Health Cooperative Research Centre, Melbourne Dental School, and Bio21 Institute, and Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3010, Australia, and
| | - Divya Ramnath
- the Institute for Molecular Bioscience, and Australian Infectious Disease Research Centre, The University of Queensland, Queensland 4072, Australia
| | - Dominic De Nardo
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3010, Australia, and
| | - Pui Yeng Lam
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3010, Australia, and
| | - Eric C Reynolds
- From the Oral Health Cooperative Research Centre, Melbourne Dental School, and Bio21 Institute, and
| | - John A Hamilton
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3010, Australia, and
| | - Matthew J Sweet
- the Institute for Molecular Bioscience, and Australian Infectious Disease Research Centre, The University of Queensland, Queensland 4072, Australia
| | - Glen M Scholz
- From the Oral Health Cooperative Research Centre, Melbourne Dental School, and Bio21 Institute, and Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3010, Australia, and
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Webster Marketon JI, Corry J, Teng MN. The respiratory syncytial virus (RSV) nonstructural proteins mediate RSV suppression of glucocorticoid receptor transactivation. Virology 2014; 449:62-9. [PMID: 24418538 PMCID: PMC3904736 DOI: 10.1016/j.virol.2013.11.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 07/12/2013] [Accepted: 11/06/2013] [Indexed: 12/22/2022]
Abstract
Respiratory syncytial virus (RSV)-induced bronchiolitis in infants is not responsive to glucocorticoids. We have shown that RSV infection impairs glucocorticoid receptor (GR) function. In this study, we have investigated the mechanism by which RSV impairs GR function. We have shown that RSV repression of GR-induced transactivation is not mediated through a soluble autocrine factor. Knock-down of mitochondrial antiviral signaling protein (MAVS), but not retinoic acid-inducible gene 1 (RIG-I) or myeloid differentiation primary response gene 88 (MyD88), impairs GR-mediated gene activation even in mock-infected cells. Over-expression of the RSV nonstructural protein NS1, but not NS2, impairs glucocorticoid-induced transactivation and viruses deleted in NS1 and/or NS2 are unable to repress glucocorticoid-induction of the known GR regulated gene glucocorticoid-inducible leucine zipper (GILZ). These data suggest that the RSV nonstructural proteins mediate RSV repression of GR-induced transactivation and that inhibition of the nonstructural proteins may be a viable target for therapy against RSV-related disease.
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Affiliation(s)
- Jeanette I Webster Marketon
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Internal Medicine, Wexner Medical Center at The Ohio State University, Columbus, OH 43210, United States; Institute for Behavioral Medicine Research, Wexner Medical Center at The Ohio State University, Columbus, OH 43210, United States.
| | - Jacqueline Corry
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Internal Medicine, Wexner Medical Center at The Ohio State University, Columbus, OH 43210, United States.
| | - Michael N Teng
- Joy McCann Culverhouse Airway Disease Research Center, Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, United States
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Bao X, Kolli D, Ren J, Liu T, Garofalo RP, Casola A. Human metapneumovirus glycoprotein G disrupts mitochondrial signaling in airway epithelial cells. PLoS One 2013; 8:e62568. [PMID: 23626834 PMCID: PMC3633857 DOI: 10.1371/journal.pone.0062568] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 03/22/2013] [Indexed: 12/21/2022] Open
Abstract
Human metapneumovirus (hMPV) is a recently identified RNA virus belonging to the Paramyxoviridae family. It is a common cause of respiratory tract infections in children, adults, and immunocompromised patients, for which no specific treatment or vaccine is available. Recent investigations in our lab identified hMPV glycoprotein G as an important virulence factor, as a recombinant virus lacking the G protein (rhMPV-ΔG) exhibited enhanced production of important immune and antiviral mediators, such as cytokines, chemokines and type I interferon (IFN) in airway epithelial cells, and expression of G protein alone inhibits cellular signaling dependent on retinoic induced gene (RIG)-I, a RNA helicase with a fundamental role in initiating hMPV-induced cellular responses. In this study, we have further investigated the mechanism underlying the inhibitory role of hMPV G protein on RIG-I-dependent signaling. We found that the interaction of hMPV G with RIG-I occurs primarily through the CARD domains of RIG-I N-terminus, preventing RIG-I association with the adaptor protein MAVS (mitochondrial antiviral signaling protein), recruitment of RIG-I to mitochondria, as well as the interaction between mitochondria and mitochondria-associated membrane (MAM) component of the endoplasmic reticulum (ER), which contains STINGS, an important part of the viral-induced RIG-I/MAVS signaling pathway, leading in the end to the inhibition of cytokine, chemokine and type I IFN expression. Mutagenesis analysis showed that hMPV G protein cytoplasmic domain played a major role in the observed inhibitory activity, and recombinant viruses expressing a G protein with amino acid substitution in position 2 and 3 recapitulated most of the phenotype observed with rhMPV-ΔG mutant upon infection of airway epithelial cells.
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Affiliation(s)
- Xiaoyong Bao
- Department of Pediatrics, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
- * E-mail: (XB); (AC)
| | - Deepthi Kolli
- Department of Pediatrics, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
| | - Junping Ren
- Department of Pediatrics, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
| | - Tianshuang Liu
- Department of Pediatrics, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
| | - Roberto P. Garofalo
- Department of Pediatrics, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
- Department of Microbiology and Immunology, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
- Sealy Center for Vaccine Development, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
| | - Antonella Casola
- Department of Pediatrics, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
- Department of Microbiology and Immunology, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
- Sealy Center for Vaccine Development, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
- * E-mail: (XB); (AC)
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CDK9-dependent transcriptional elongation in the innate interferon-stimulated gene response to respiratory syncytial virus infection in airway epithelial cells. J Virol 2013; 87:7075-92. [PMID: 23596302 DOI: 10.1128/jvi.03399-12] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Respiratory syncytial virus (RSV) is a negative-sense single-stranded RNA virus responsible for lower respiratory tract infections. During infection, the presence of double-stranded RNA (dsRNA) activates the interferon (IFN) regulatory factor 3 (IRF3) transcription factor, an event triggering expression of immediate early, IFN-stimulated genes (ISGs). We examine the role of transcriptional elongation in control of IRF3-dependent ISG expression. RSV infection induces ISG54, ISG56, and CIG5 gene expression in an IRF3-dependent manner demonstrated by IRF3 small interfering RNA (siRNA) silencing in both A549 epithelial cells and IRF3(-/-) MEFs. ISG expression was mediated by the recruitment of IRF3, CDK9, polymerase II (Pol II), and phospho-Ser(2) carboxy-terminal domain (CTD) Pol II to the IFN-stimulated response element (ISRE) binding sites of the IRF3-dependent ISG promoters in native chromatin. We find that RSV infection enhances the activated fraction of cyclin-dependent kinase 9 (CDK9) by promoting its association with bromodomain 4 (BRD4) and disrupting its association with the inhibitory 7SK small nuclear RNA. The requirement of CDK9 activity for ISG expression was shown by siRNA-mediated silencing of CDK9 and by a selective CDK9 inhibitor in A549 cells. In contrast, RSV-induced beta interferon (IFN-β) expression is not influenced by CDK9 inhibition. Using transcript-selective quantitative real-time reverse transcription-PCR (Q-RT-PCR) assays for the ISG54 gene, we observed that RSV induces transition from short to fully spliced mRNA transcripts and that this transition is blocked by CDK9 inhibition in both A549 and primary human small airway epithelial cells. These data indicate that transcription elongation plays a major role in RSV-induced ISG expression and is mediated by IRF3-dependent recruitment of activated CDK9. CDK9 activity may be a target for immunomodulation in RSV-induced lung disease.
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Lotz MT, Peebles RS. Mechanisms of respiratory syncytial virus modulation of airway immune responses. Curr Allergy Asthma Rep 2013; 12:380-7. [PMID: 22692775 PMCID: PMC3432290 DOI: 10.1007/s11882-012-0278-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Respiratory syncytial virus (RSV) most often causes severe respiratory disease in the very young and the elderly. Acute disease can also cause exacerbations of asthma in any age group. Recent findings provide insight into how the innate and adaptive immune systems respond to RSV infection and provide preliminary evidence that these effects vary significantly by RSV strain and host. Components of cell signaling pathways that induce inflammatory cytokine expression during the innate immune response and alter epithelial cell polarity through activating transcription factors, namely NF-κB, are now more clearly understood. New studies also reveal how RSV infection skews T helper (Th) cell differentiation away from the cell-mediated Th1 subset and towards the Th2 subset. There are also new data supporting preferential Th17 differentiation during RSV infection. In addition, effective immune system regulation of IL-10 expression and T regulatory cell (Treg) airway accumulation are essential for effective RSV clearance.
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Affiliation(s)
- Matthew T Lotz
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232-2650, USA
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40
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Ravi LI, Li L, Sutejo R, Chen H, Wong PS, Tan BH, Sugrue RJ. A systems-based approach to analyse the host response in murine lung macrophages challenged with respiratory syncytial virus. BMC Genomics 2013; 14:190. [PMID: 23506210 PMCID: PMC3618260 DOI: 10.1186/1471-2164-14-190] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 03/08/2013] [Indexed: 12/22/2022] Open
Abstract
Background Respiratory syncytial virus (RSV) is an important cause of lower respiratory tract infection in young children. The degree of disease severity is determined by the host response to infection. Lung macrophages play an important early role in the host response to infection and we have used a systems-based approach to examine the host response in RSV-infected lung-derived macrophage cells. Results Lung macrophage cells could be efficiently infected (>95%) with RSV in vitro, and the expression of several virus structural proteins could be detected. Although we failed to detect significant levels of virus particle production, virus antigen could be detected up until 96 hours post-infection (hpi). Microarray analysis indicated that 20,086 annotated genes were expressed in the macrophage cells, and RSV infection induced an 8.9% and 11.3% change in the global gene transcriptome at 4 hpi and 24 hpi respectively. Genes showing up-regulated expression were more numerous and exhibited higher changes in expression compared to genes showing down-regulated expression. Based on gene ontology, genes with cytokine, antiviral, cell death, and signal transduction functions showed the highest increases in expression, while signalling transduction, RNA binding and protein kinase genes showed the greatest reduction in expression levels. Analysis of the global gene expression profile using pathway enrichment analysis confirmed that up-regulated expression of pathways related to pathogen recognition, interferon signalling and antigen presentation occurred in the lung macrophage cells challenged with RSV. Conclusion Our data provided a comprehensive analysis of RSV-induced gene expression changes in lung macrophages. Although virus gene expression was detected, our data was consistent with an abortive infection and this correlated with the activation of several antivirus signalling pathways such as interferon type I signalling and cell death signalling. RSV infection induced a relatively large increase in pro-inflammatory cytokine expression, however the maintenance of this pro-inflammatory response was not dependent on the production of infectious virus particles. The sustained pro-inflammatory response even in the absence of a productive infection suggests that drugs that control the pro-inflammatory response may be useful in the treatment of patients with severe RSV infection.
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Affiliation(s)
- Laxmi Iyer Ravi
- Division of Molecular Genetics and Cell Biology, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
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41
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Small hydrophobic protein of human metapneumovirus does not affect virus replication and host gene expression in vitro. PLoS One 2013; 8:e58572. [PMID: 23484037 PMCID: PMC3590193 DOI: 10.1371/journal.pone.0058572] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 02/07/2013] [Indexed: 12/11/2022] Open
Abstract
Human metapneumovirus (HMPV) encodes a small hydrophobic (SH) protein of unknown function. HMPV from which the SH open reading frame was deleted (HMPVΔSH) was viable and displayed similar replication kinetics, cytopathic effect and plaque size compared with wild type HMPV in several cell-lines. In addition, no differences were observed in infection efficiency or cell-to-cell spreading in human primary bronchial epithelial cells (HPBEC) cultured at an air-liquid interphase. Host gene expression was analyzed in A549 cells infected with HMPV or HMPVΔSH using microarrays and mass spectrometry (MS) based techniques at multiple time points post infection. Only minor differences were observed in mRNA or protein expression levels. A possible function of HMPV SH as apoptosis blocker, as proposed for several members of the family Paramyxoviridae, was rejected based on this analysis. So far, a clear phenotype of HMPV SH deletion mutants in vitro at the virus and host levels is absent.
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42
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Garofalo RP, Kolli D, Casola A. Respiratory syncytial virus infection: mechanisms of redox control and novel therapeutic opportunities. Antioxid Redox Signal 2013; 18:186-217. [PMID: 22799599 PMCID: PMC3513983 DOI: 10.1089/ars.2011.4307] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Respiratory syncytial virus (RSV) is one of the most important causes of upper and lower respiratory tract infections in infants and young children, for which no effective treatment is currently available. Although the mechanisms of RSV-induced airway disease remain incompletely defined, the lung inflammatory response is thought to play a central pathogenetic role. In the past few years, we and others have provided increasing evidence of a role of reactive oxygen species (ROS) as important regulators of RSV-induced cellular signaling leading to the expression of key proinflammatory mediators, such as cytokines and chemokines. In addition, RSV-induced oxidative stress, which results from an imbalance between ROS production and airway antioxidant defenses, due to a widespread inhibition of antioxidant enzyme expression, is likely to play a fundamental role in the pathogenesis of RSV-associated lung inflammatory disease, as demonstrated by a significant increase in markers of oxidative injury, which correlate with the severity of clinical illness, in children with RSV infection. Modulation of ROS production and oxidative stress therefore represents a potential novel pharmacological approach to ameliorate RSV-induced lung inflammation and its long-term consequences.
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Affiliation(s)
- Roberto P Garofalo
- Department of Pediatrics, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
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Ramakrishna L, de Vries VC, Curotto de Lafaille MA. Cross-roads in the lung: immune cells and tissue interactions as determinants of allergic asthma. Immunol Res 2012; 53:213-28. [PMID: 22447350 DOI: 10.1007/s12026-012-8296-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Allergic asthma is a chronic disease of the lung characterized by underlying Th2- and IgE-mediated inflammation, structural alterations of the bronchial wall, and airway hyperresponsiveness. Initial allergic sensitization and later development of chronic disease are determined by close interactions between lung structural cells and the resident and migratory immune cells in the lung. Epithelial cells play a crucial role in allergic sensitization by directly influencing dendritic cells induction of tolerant or effector T cells and production of type 2 cytokines by innate immune cells. During chronic disease, the bronchial epithelium, stroma, and smooth muscle become structurally and functionally altered, contributing to the perpetuation of tissue remodeling. Thus, targeting tissue-driven pathology in addition to inflammation may increase the effectiveness of asthma treatment.
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Affiliation(s)
- Lakshmi Ramakrishna
- Singapore Immunology Network, Agency for Science, Technology and Research, 8A Biomedical Grove, #4-06 Immunos, Singapore
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44
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Hosakote YM, Komaravelli N, Mautemps N, Liu T, Garofalo RP, Casola A. Antioxidant mimetics modulate oxidative stress and cellular signaling in airway epithelial cells infected with respiratory syncytial virus. Am J Physiol Lung Cell Mol Physiol 2012; 303:L991-1000. [PMID: 23023968 DOI: 10.1152/ajplung.00192.2012] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Respiratory syncytial virus (RSV) is one of the most common causes of bronchiolitis and pneumonia among infants and young children worldwide. In previous investigations, we have shown that RSV infection induces rapid generation of reactive oxygen species (ROS), which modulate viral-induced cellular signaling, and downregulation of antioxidant enzyme (AOE) expression, resulting in oxidative stress in vitro and in vivo, which plays a pathogenetic role in RSV-induced lung disease. In this study, we determined whether pharmacological intervention with synthetic catalytic scavengers could reduce RSV-induced proinflammatory gene expression and oxidative cell damage in an in vitro model of infection. Treatment of airway epithelial cells (AECs) with the salen-manganese complexes EUK-8 or EUK-189, which possess superoxide dismutase, catalase, and glutathione peroxidase activity, strongly reduced RSV-induced ROS formation by increasing cellular AOE enzymatic activity and levels of the lipid peroxidation products F(2)-8-isoprostane and malondialdehyde, which are markers of oxidative stress. Treatment of AECs with AOE mimetics also significantly inhibited RSV-induced cytokine and chemokine secretion and activation of the transcription factors nuclear factor-κB and interferon regulatory factor-3, which orchestrate proinflammatory gene expression. Both EUKs were able to reduce viral replication, when used at high doses. These results suggest that increasing antioxidant cellular capacities can significantly impact RSV-associated oxidative cell damage and cellular signaling and could represent a novel therapeutic approach in modulating virus-induced lung disease.
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Affiliation(s)
- Yashoda M Hosakote
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX 77555, USA
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45
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Human metapneumovirus M2-2 protein inhibits innate cellular signaling by targeting MAVS. J Virol 2012; 86:13049-61. [PMID: 23015697 DOI: 10.1128/jvi.01248-12] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Human metapneumovirus (hMPV) is a leading cause of respiratory infections in pediatric populations globally, with no prophylactic or therapeutic measures. Recently, a recombinant hMPV lacking the M2-2 protein (rhMPV-ΔM2-2) demonstrated reduced replication in the respiratory tract of animal models, making it a promising live vaccine candidate. However, the exact nature of the interaction between the M2-2 protein and host cells that regulates viral infection/propagation is largely unknown. By taking advantage of the available reverse genetics system and ectopic expression system for viral protein, we found that M2-2 not only promotes viral gene transcription and replication but subverts host innate immunity, therefore identifying M2-2 as a novel virulence factor, in addition to the previously described hMPV G protein. Since we have shown that the RIG-I/MAVS pathway plays an important role in hMPV-induced signaling in airway epithelial cells, we investigated whether M2-2 antagonizes the host cellular responses by targeting this pathway. Reporter gene assays and coimmunoprecipitation studies indicated that M2-2 targets MAVS, an inhibitory mechanism different from what we previously reported for hMPV G, which affects RIG-I- but not MAVS-dependent gene transcription. In addition, we found that the domains of M2-2 responsible for the regulation of viral gene transcription and antiviral signaling are different. Our findings collectively demonstrate that M2-2 contributes to hMPV immune evasion through the inhibition of MAVS-dependent cellular responses.
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46
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Marr N, Turvey SE. Role of human TLR4 in respiratory syncytial virus-induced NF-κB activation, viral entry and replication. Innate Immun 2012; 18:856-65. [PMID: 22535679 DOI: 10.1177/1753425912444479] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
TLRs play a key role in innate immune defenses. It was previously reported that purified respiratory syncytial virus (RSV) fusion protein elicits an inflammatory response in hematopoietic cells, which required expression of TLR4 and its co-receptor CD14. However, a biological role of TLR4 in immunity to RSV, as initially proposed, has remained inconclusive and controversial. Here, we directly assess the role of human TLR4 and its co-receptors in NF-κB activation, viral entry and replication using intact virions rather than purified RSV components. We used HEK 293 reporter cells that are highly permissive for RSV and that either express or a lack a functional human TLR4/MD-2/CD14 complex. We demonstrate that RSV-mediated NF-κB activation, viral entry and replication are independent of the expression of a functional human TLR4/MD-2/CD14 complex and that, in turn, human TLR4 activation by LPS remains unaffected in RSV-infected cells. Thus, although isolated viral compounds such as purified RSV F protein may bind TLR4 and/or CD14, a direct interaction between intact RSV particles and the human TLR4 receptor complex does not seem to play a biological role in RSV pathogenesis.
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Affiliation(s)
- Nico Marr
- Department of Pediatrics, University of British Columbia and the Child & Family Research Institute, Vancouver, Canada.
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47
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Different NF-κB activation characteristics of human respiratory syncytial virus subgroups A and B. Microb Pathog 2012; 52:184-91. [DOI: 10.1016/j.micpath.2011.12.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Revised: 12/22/2011] [Accepted: 12/24/2011] [Indexed: 11/21/2022]
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48
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RelA Ser276 phosphorylation-coupled Lys310 acetylation controls transcriptional elongation of inflammatory cytokines in respiratory syncytial virus infection. J Virol 2011; 85:11752-69. [PMID: 21900162 DOI: 10.1128/jvi.05360-11] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Respiratory syncytial virus (RSV) is a negative-sense single-stranded RNA virus responsible for lower respiratory tract infections (LRTIs) in humans. In experimental models of RSV LRTI, the actions of the nuclear factor κB (NF-κB) transcription factor mediate inflammation and pathology. We have shown that RSV replication induces a mitogen-and-stress-related kinase 1 (MSK-1) pathway that activates NF-κB RelA transcriptional activity by a process involving serine phosphorylation at serine (Ser) residue 276. In this study, we examined the mechanism by which phospho-Ser276 RelA mediates expression of the NF-κB-dependent gene network. RelA-deficient mouse embryonic fibroblasts (MEFs) complemented with the RelA Ser276Ala mutant are deficient in CXCL2/Groβ, KC, and interleukin-6 (IL-6) expression, but NFKBIA/IκBα is preserved. We show that RSV-induced RelA Ser276 phosphorylation is required for acetylation at Lys310, an event required for transcriptional activity and stable association of RelA with the activated positive transcriptional elongation factor (PTEF-b) complex proteins, bromodomain 4 (Brd4), and cyclin-dependent kinase 9 (CDK9). In contrast to gene loading pattern of PTEF-b proteins produced by tumor necrosis factor (TNF) stimulation, RSV induces their initial clearance followed by partial reaccumulation coincident with RelA recruitment. The RSV-induced binding patterns of the CDK9 substrate, phospho-Ser2 RNA polymerase (Pol) II, follows a similar pattern of clearance and downstream gene reaccumulation. The functional role of CDK9 was examined using CDK9 small interfering RNA (siRNA) and CDK inhibitors, where RSV-induced NF-κB-dependent gene expression was significantly inhibited. Finally, although RSV induces a transition from short transcripts to fully spliced mRNA in wild-type RelA (RelA WT)-expressing cells, this transition is not seen in cells expressing RelA Ser276Ala. We conclude that RelA Ser276 phosphorylation mediates RelA acetylation, Brd4/CDK9 association, and activation of downstream inflammatory genes by transcriptional elongation in RSV infection.
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Dey N, Liu T, Garofalo RP, Casola A. TAK1 regulates NF-ΚB and AP-1 activation in airway epithelial cells following RSV infection. Virology 2011; 418:93-101. [PMID: 21835421 DOI: 10.1016/j.virol.2011.07.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 06/06/2011] [Accepted: 07/01/2011] [Indexed: 01/26/2023]
Abstract
Respiratory syncytial virus (RSV) is the most common cause of epidemic respiratory diseases in infants and young children. RSV infection of airway epithelial cells induces the expression of immune/inflammatory genes through the activation of a subset of transcription factors, including Nuclear Factor-κB (NF-κB) and AP-1. In this study, we have investigated the signaling pathway leading to activation of these two transcription factors in response to RSV infection. Our results show that IKKβ plays a key role in viral-induced NF-κB activation, while JNK regulates AP-1-dependent gene transcription, as demonstrated by using kinase inactive proteins and chemical inhibitors of the two kinases. Inhibition of TAK1 activation, by overexpression of kinase inactive TAK1 or using cells lacking TAK1 expression, significantly reduced RSV-induced NF-κB and AP-1 nuclear translocation and DNA-binding activity, as well as NF-κB-dependent gene expression, identifying TAK1 as an important upstream signaling molecule regulating RSV-induced NF-κB and AP-1 activation.
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Affiliation(s)
- Nilay Dey
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX, USA
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Zhao Y, Widen SG, Jamaluddin M, Tian B, Wood TG, Edeh CB, Brasier AR. Quantification of activated NF-kappaB/RelA complexes using ssDNA aptamer affinity-stable isotope dilution-selected reaction monitoring-mass spectrometry. Mol Cell Proteomics 2011; 10:M111.008771. [PMID: 21502374 PMCID: PMC3108844 DOI: 10.1074/mcp.m111.008771] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 04/08/2011] [Indexed: 12/12/2022] Open
Abstract
Nuclear Factor-κB (NF-κB) is a family of inducible transcription factors regulated by stimulus-induced protein interactions. In the cytoplasm, the NF-κB member RelA transactivator is inactivated by binding inhibitory IκBs, whereas in its activated state, the serine-phosphorylated protein binds the p300 histone acetyltransferase. Here we describe the isolation of a ssDNA aptamer (termed P028F4) that binds to the activated (IκBα-dissociated) form of RelA with a K(D) of 6.4 × 10(-10), and its application in an enrichment-mass spectrometric quantification assay. ssDNA P028F4 competes with cognate duplex high affinity NF-κB binding sites for RelA binding in vitro, binds activated RelA in eukaryotic nuclei and reduces TNFα-stimulated endogenous NF-κB dependent gene expression. Incorporation of P028F4 as an affinity isolation step enriches for serine 536 phosphorylated and p300 coactivator complexed RelA, simultaneously depleting IκBα·RelA complexes. A stable isotope dilution (SID)-selected reaction monitoring (SRM)- mass spectrometry (MS) assay for RelA was developed that produced a linear response over 1,000 fold dilution range of input protein and had a 200 amol lower limit of quantification. This multiplex SID-SRM-MS RelA assay was used to quantify activated endogenous RelA in cytokine-stimulated eukaryotic cells isolated by single-step P028F4 enrichment. The aptamer-SID-SRM-MS assay quantified the fraction of activated RelA in subcellular extracts, detecting the presence of a cytoplasmic RelA reservoir unresponsive to TNFα stimulation. We conclude that aptamer-SID-SRM-MS is a versatile tool for quantification of activated NF-κB/RelA and its associated complexes in response to pathway activation.
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Affiliation(s)
- Yingxin Zhao
- From the ‡Sealy Center for Molecular Medicine
- §Department of Internal Medicine
| | | | | | | | - Thomas G. Wood
- From the ‡Sealy Center for Molecular Medicine
- the ¶¶Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555
| | | | - Allan R. Brasier
- From the ‡Sealy Center for Molecular Medicine
- §Department of Internal Medicine
- ¶Institute for Translational Sciences, and
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