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González Aparicio LJ, López CB. Selection of nonstandard viral genomes during the evolution of RNA viruses: A virus survival strategy or a pesky inconvenience? Adv Virus Res 2024; 119:39-61. [PMID: 38897708 DOI: 10.1016/bs.aivir.2024.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
RNA viruses are some of the most successful biological entities due their ability to adapt and evolve. Despite their small genome and parasitic nature, RNA viruses have evolved many mechanisms to ensure their survival and maintenance in the host population. We propose that one of these mechanisms of survival is the generation of nonstandard viral genomes (nsVGs) that accumulate during viral replication. NsVGs are often considered to be accidental defective byproducts of the RNA virus replication, but their ubiquity and the plethora of roles they have during infection indicate that they are an integral part of the virus life cycle. Here we review the different types of nsVGs and discuss how their multiple roles during infection could be beneficial for RNA viruses to be maintained in nature. By shifting our perspectives on what makes a virus successful, we posit that nsVG generation is a conserved phenomenon that arose during RNA virus evolution as an essential component of a healthy virus community.
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Affiliation(s)
- Lavinia J González Aparicio
- Department of Molecular Microbiology and Center for Women Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, MO, United States
| | - Carolina B López
- Department of Molecular Microbiology and Center for Women Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, MO, United States.
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2
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Brennan JW, Sun Y. Defective viral genomes: advances in understanding their generation, function, and impact on infection outcomes. mBio 2024; 15:e0069224. [PMID: 38567955 PMCID: PMC11077978 DOI: 10.1128/mbio.00692-24] [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] [Indexed: 05/09/2024] Open
Abstract
Defective viral genomes (DVGs) are truncated derivatives of their parental viral genomes generated during an aberrant round of viral genomic replication. Distinct classes of DVGs have been identified in most families of both positive- and negative-sense RNA viruses. Importantly, DVGs have been detected in clinical samples from virally infected individuals and an emerging body of association studies implicates DVGs in shaping the severity of disease caused by viral infections in humans. Consequently, there is growing interest in understanding the molecular mechanisms of de novo DVG generation, how DVGs interact with the innate immune system, and harnessing DVGs as novel therapeutics and vaccine adjuvants to attenuate viral pathogenesis. This minireview focuses on single-stranded RNA viruses (excluding retroviridae), and summarizes the current knowledge of DVG generation, the functions and diversity of DVG species, the roles DVGs play in influencing disease progression, and their application as antivirals and vaccine adjuvants.
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Affiliation(s)
- Justin W. Brennan
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York, USA
| | - Yan Sun
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York, USA
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3
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González Aparicio LJ, Yang Y, Hackbart M, López CB. Copy-back viral genomes induce a cellular stress response that interferes with viral protein expression without affecting antiviral immunity. PLoS Biol 2023; 21:e3002381. [PMID: 37983241 PMCID: PMC10695362 DOI: 10.1371/journal.pbio.3002381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 12/04/2023] [Accepted: 10/15/2023] [Indexed: 11/22/2023] Open
Abstract
Antiviral responses are often accompanied by translation inhibition and formation of stress granules (SGs) in infected cells. However, the triggers for these processes and their role during infection remain subjects of active investigation. Copy-back viral genomes (cbVGs) are the primary inducers of the mitochondrial antiviral signaling (MAVS) pathway and antiviral immunity during Sendai virus (SeV) and respiratory syncytial virus (RSV) infections. The relationship between cbVGs and cellular stress during viral infections is unknown. Here, we show that SGs form during infections containing high levels of cbVGs, and not during infections with low levels of cbVGs. Moreover, using RNA fluorescent in situ hybridization to differentiate accumulation of standard viral genomes from cbVGs at a single-cell level during infection, we show that SGs form exclusively in cells that accumulate high levels of cbVGs. Protein kinase R (PKR) activation is increased during high cbVG infections and, as expected, is necessary for virus-induced SGs. However, SGs form independent of MAVS signaling, demonstrating that cbVGs induce antiviral immunity and SG formation through 2 independent mechanisms. Furthermore, we show that translation inhibition and SG formation do not affect the overall expression of interferon and interferon stimulated genes during infection, making the stress response dispensable for global antiviral immunity. Using live-cell imaging, we show that SG formation is highly dynamic and correlates with a drastic reduction of viral protein expression even in cells infected for several days. Through analysis of active protein translation at a single-cell level, we show that infected cells that form SGs show inhibition of protein translation. Together, our data reveal a new cbVG-driven mechanism of viral interference where cbVGs induce PKR-mediated translation inhibition and SG formation, leading to a reduction in viral protein expression without altering overall antiviral immunity.
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Affiliation(s)
- Lavinia J. González Aparicio
- Department of Molecular Microbiology and Center for Women Infectious Disease Research, Washington University School of Medicine in St. Louis, Missouri, United States of America
| | - Yanling Yang
- Department of Molecular Microbiology and Center for Women Infectious Disease Research, Washington University School of Medicine in St. Louis, Missouri, United States of America
| | - Matthew Hackbart
- Department of Molecular Microbiology and Center for Women Infectious Disease Research, Washington University School of Medicine in St. Louis, Missouri, United States of America
| | - Carolina B. López
- Department of Molecular Microbiology and Center for Women Infectious Disease Research, Washington University School of Medicine in St. Louis, Missouri, United States of America
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4
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Smith JR, Dowling JW, McFadden MI, Karp A, Schwerk J, Woodward JJ, Savan R, Forero A. MEF2A suppresses stress responses that trigger DDX41-dependent IFN production. Cell Rep 2023; 42:112805. [PMID: 37467105 PMCID: PMC10652867 DOI: 10.1016/j.celrep.2023.112805] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 05/17/2023] [Accepted: 06/27/2023] [Indexed: 07/21/2023] Open
Abstract
Cellular stress in the form of disrupted transcription, loss of organelle integrity, or damage to nucleic acids can elicit inflammatory responses by activating signaling cascades canonically tasked with controlling pathogen infections. These stressors must be kept in check to prevent unscheduled activation of interferon, which contributes to autoinflammation. This study examines the role of the transcription factor myocyte enhancing factor 2A (MEF2A) in setting the threshold of transcriptional stress responses to prevent R-loop accumulation. Increases in R-loops lead to the induction of interferon and inflammatory responses in a DEAD-box helicase 41 (DDX41)-, cyclic GMP-AMP synthase (cGAS)-, and stimulator of interferon genes (STING)-dependent manner. The loss of MEF2A results in the activation of ATM and RAD3-related (ATR) kinase, which is also necessary for the activation of STING. This study identifies the role of MEF2A in sustaining transcriptional homeostasis and highlights the role of ATR in positively regulating R-loop-associated inflammatory responses.
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Affiliation(s)
- Julian R Smith
- Department of Immunology, University of Washington, Seattle, WA 98109, USA
| | - Jack W Dowling
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Matthew I McFadden
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH 43210, USA; Biomedical Sciences Graduate Program, The Ohio State University, Columbus, OH 43210, USA
| | - Andrew Karp
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH 43210, USA; Discovery PREP, The Ohio State University, Columbus, OH 43210, USA
| | - Johannes Schwerk
- Department of Immunology, University of Washington, Seattle, WA 98109, USA
| | - Joshua J Woodward
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Ram Savan
- Department of Immunology, University of Washington, Seattle, WA 98109, USA
| | - Adriana Forero
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH 43210, USA; Cancer Biology Program, Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA; Infectious Diseases Institute, The Ohio State University, Columbus, OH 43210, USA.
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5
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Lopez CB, Gonzalez Aparicio LJ, Yang Y, Hackbart MS. Copy-back viral genomes induce a cellular stress response that interferes with viral protein expression without affecting antiviral immunity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.17.541157. [PMID: 37292625 PMCID: PMC10245731 DOI: 10.1101/2023.05.17.541157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Antiviral responses are often accompanied by translation inhibition and formation of stress granules (SG) in infected cells. However, the triggers for these processes and their role during infection remain subjects of active investigation. Copy-back viral genomes (cbVGs) are the primary inducers of the Mitochondrial Antiviral Signaling (MAVS) pathway and antiviral immunity during Sendai Virus (SeV) and Respiratory Syncytial virus (RSV) infections. The relationship between cbVGs and cellular stress during viral infections is unknown. Here we show that SG form during infections containing high levels of cbVGs, and not during infections with low levels of cbVGs. Moreover, using RNA fluorescent in situ hybridization to differentiate accumulation of standard viral genomes from cbVGs at a single-cell level during infection, we show that SG form exclusively in cells that accumulate high levels of cbVGs. PKR activation is increased during high cbVG infections and, as expected, PKR is necessary to induce virus-induced SG. However, SG form independent of MAVS signaling, demonstrating that cbVGs induce antiviral immunity and SG formation through two independent mechanisms. Furthermore, we show that translation inhibition and SG formation do not affect the overall expression of interferon and interferon stimulated genes during infection, making the stress response dispensable for antiviral immunity. Using live-cell imaging, we show that SG formation is highly dynamic and correlates with a drastic reduction of viral protein expression even in cells infected for several days. Through analysis of active protein translation at a single cell level, we show that infected cells that form SG show inhibition of protein translation. Together, our data reveal a new cbVG-driven mechanism of viral interference where cbVGs induce PKR-mediated translation inhibition and SG formation leading to a reduction in viral protein expression without altering overall antiviral immunity.
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6
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Delima GK, Ganti K, Holmes KE, Shartouny JR, Lowen AC. Influenza A virus coinfection dynamics are shaped by distinct virus-virus interactions within and between cells. PLoS Pathog 2023; 19:e1010978. [PMID: 36862762 PMCID: PMC10013887 DOI: 10.1371/journal.ppat.1010978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 03/14/2023] [Accepted: 02/07/2023] [Indexed: 03/03/2023] Open
Abstract
When multiple viral populations propagate within the same host environment, they often shape each other's dynamics. These interactions can be positive or negative and can occur at multiple scales, from coinfection of a cell to co-circulation at a global population level. For influenza A viruses (IAVs), the delivery of multiple viral genomes to a cell substantially increases burst size. However, despite its relevance for IAV evolution through reassortment, the implications of this positive density dependence for coinfection between distinct IAVs has not been explored. Furthermore, the extent to which these interactions within the cell shape viral dynamics at the level of the host remains unclear. Here we show that, within cells, diverse coinfecting IAVs strongly augment the replication of a focal strain, irrespective of their homology to the focal strain. Coinfecting viruses with a low intrinsic reliance on multiple infection offer the greatest benefit. Nevertheless, virus-virus interactions at the level of the whole host are antagonistic. This antagonism is recapitulated in cell culture when the coinfecting virus is introduced several hours prior to the focal strain or under conditions conducive to multiple rounds of viral replication. Together, these data suggest that beneficial virus-virus interactions within cells are counterbalanced by competition for susceptible cells during viral propagation through a tissue. The integration of virus-virus interactions across scales is critical in defining the outcomes of viral coinfection.
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Affiliation(s)
- Gabrielle K. Delima
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Ketaki Ganti
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Katie E. Holmes
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Jessica R. Shartouny
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Anice C. Lowen
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, United States of America
- Emory Center of Excellence for Influenza Research and Response (Emory-CEIRR), Atlanta, Georgia, United States of America
- * E-mail:
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7
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Karki B, Bull JJ, Krone SM. Modeling the Therapeutic Potential of Defective Interfering Particles in the Presence of Immunity. Virus Evol 2022; 8:veac047. [PMID: 35799886 PMCID: PMC9255601 DOI: 10.1093/ve/veac047] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 05/29/2022] [Accepted: 06/07/2022] [Indexed: 11/23/2022] Open
Abstract
Defective interfering particles (DIPs) are naturally occurring viruses that have evolved to parasitize other viruses. They suppress wild-type (WT) virus infections through their role as intracellular parasites. Because most encode few or no viral proteins, they have been entertained as possible safe antiviral therapies—something that might be given to patients infected with the WT virus. Adding to their safety, they cannot reproduce except when co-infecting the same cells as the WT, so they pose no danger of evolving into independent disease agents. But this dependence on the WT also limits their therapeutic utility by restricting the timing at which their administration can be effective. To develop a qualitative sense of these constraints for acute viral infections, we use ordinary differential equation models to study the mass-action dynamics of DIPs and WT virus in the presence of adaptive and innate immunity that will otherwise clear the infection. Our goal is to understand whether the therapeutic administration of DIPs will augment or interfere with the immune response and, in the former case, we seek to provide guidance on how virus suppression is affected by infection and clearance parameters, as well as by the timing of DIP introduction. Consistent with previous theoretical work, we find that DIPs can significantly suppress viral load. When immunity is present, the timing of DIP administration matters, with an intermediate optimum. When successful at viral suppression, DIPs even slow the immune response, but the combined effect of DIPs and immunity is still beneficial. Outcomes depend somewhat on whether immunity is elicited by and clears DIPs, but timing appears to have the greater effect.
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Affiliation(s)
- Bandita Karki
- Department of Mathematics and Statistical Science, University of Idaho , Moscow, ID 83844-1103 USA
| | - James J Bull
- Department of Biological Sciences, University of Idaho , Moscow, ID 83844-3051 USA
| | - Stephen M Krone
- Department of Mathematics and Statistical Science, University of Idaho , Moscow, ID 83844-1103 USA
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8
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A Virus Is a Community: Diversity within Negative-Sense RNA Virus Populations. Microbiol Mol Biol Rev 2022; 86:e0008621. [PMID: 35658541 DOI: 10.1128/mmbr.00086-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Negative-sense RNA virus populations are composed of diverse viral components that interact to form a community and shape the outcome of virus infections. At the genomic level, RNA virus populations consist not only of a homogeneous population of standard viral genomes but also of an extremely large number of genome variants, termed viral quasispecies, and nonstandard viral genomes, which include copy-back viral genomes, deletion viral genomes, mini viral RNAs, and hypermutated RNAs. At the particle level, RNA virus populations are composed of pleomorphic particles, particles missing or having additional genomes, and single particles or particle aggregates. As we continue discovering more about the components of negative-sense RNA virus populations and their crucial functions during virus infection, it will become more important to study RNA virus populations as a whole rather than their individual parts. In this review, we will discuss what is known about the components of negative-sense RNA virus communities, speculate how the components of the virus community interact, and summarize what vaccines and antiviral therapies are being currently developed to target or harness these components.
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Type I and Type II Interferon Antagonism Strategies Used by Paramyxoviridae: Previous and New Discoveries, in Comparison. Viruses 2022; 14:v14051107. [PMID: 35632848 PMCID: PMC9145045 DOI: 10.3390/v14051107] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 05/15/2022] [Accepted: 05/18/2022] [Indexed: 02/04/2023] Open
Abstract
Paramyxoviridae is a viral family within the order of Mononegavirales; they are negative single-strand RNA viruses that can cause significant diseases in both humans and animals. In order to replicate, paramyxoviruses–as any other viruses–have to bypass an important protective mechanism developed by the host’s cells: the defensive line driven by interferon. Once the viruses are recognized, the cells start the production of type I and type III interferons, which leads to the activation of hundreds of genes, many of which encode proteins with the specific function to reduce viral replication. Type II interferon is produced by active immune cells through a different signaling pathway, and activates a diverse range of genes with the same objective to block viral replication. As a result of this selective pressure, viruses have evolved different strategies to avoid the defensive function of interferons. The strategies employed by the different viral species to fight the interferon system include a number of sophisticated mechanisms. Here we analyzed the current status of the various strategies used by paramyxoviruses to subvert type I, II, and III interferon responses.
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10
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Chan CP, Jin DY. Cytoplasmic RNA sensors and their interplay with RNA-binding partners in innate antiviral response: theme and variations. RNA (NEW YORK, N.Y.) 2022; 28:449-477. [PMID: 35031583 PMCID: PMC8925969 DOI: 10.1261/rna.079016.121] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Sensing of pathogen-associated molecular patterns including viral RNA by innate immunity represents the first line of defense against viral infection. In addition to RIG-I-like receptors and NOD-like receptors, several other RNA sensors are known to mediate innate antiviral response in the cytoplasm. Double-stranded RNA-binding protein PACT interacts with prototypic RNA sensor RIG-I to facilitate its recognition of viral RNA and induction of host interferon response, but variations of this theme are seen when the functions of RNA sensors are modulated by other RNA-binding proteins to impinge on antiviral defense, proinflammatory cytokine production and cell death programs. Their discrete and coordinated actions are crucial to protect the host from infection. In this review, we will focus on cytoplasmic RNA sensors with an emphasis on their interplay with RNA-binding partners. Classical sensors such as RIG-I will be briefly reviewed. More attention will be brought to new insights on how RNA-binding partners of RNA sensors modulate innate RNA sensing and how viruses perturb the functions of RNA-binding partners.
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Affiliation(s)
- Chi-Ping Chan
- School of Biomedical Sciences and State Key Laboratory of Liver Research, Faculty of Medicine Building, Pokfulam, Hong Kong
| | - Dong-Yan Jin
- School of Biomedical Sciences and State Key Laboratory of Liver Research, Faculty of Medicine Building, Pokfulam, Hong Kong
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11
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Defective Interfering Viral Particle Treatment Reduces Clinical Signs and Protects Hamsters from Lethal Nipah Virus Disease. mBio 2022; 13:e0329421. [PMID: 35297677 PMCID: PMC9040845 DOI: 10.1128/mbio.03294-21] [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] [Indexed: 12/24/2022] Open
Abstract
Defective interfering particles (DIs) contain a considerably smaller genome than the parental virus but retain replication competency. As DIs can directly or indirectly alter propagation kinetics of the parental virus, they offer a novel approach to antiviral therapy, capitalizing on knowledge from natural infection. However, efforts to translate in vitro inhibition to in vivo screening models remain limited. We investigated the efficacy of virus-like particles containing DI genomes (therapeutic infectious particles [TIPs]) in the Syrian hamster model of lethal Nipah virus (NiV) disease. We found that coadministering a high dose of TIPs intraperitoneally with virus challenge improved clinical course and reduced lethality. To mimic natural exposure, we also evaluated lower-dose TIP delivery and virus challenge intranasally, finding equally efficacious reduction in disease severity and overall lethality. Eliminating TIP replicative capacity decreased efficacy, suggesting protection via direct inhibition. These data provide evidence that TIP-mediated treatment can confer protection against disease and lethal outcome in a robust animal NiV model, supporting further development of TIP treatment for NiV and other high-consequence pathogens. IMPORTANCE Here, we demonstrate that treatment with defective interfering particles (DIs), a natural by-product of viral infection, can significantly improve the clinical course and outcome of viral disease. When present with their parental virus, DIs can directly or indirectly alter viral propagation kinetics and exert potent inhibitory properties in cell culture. We evaluated the efficacy of a selection of virus-like particles containing DI genomes (TIPs) delivered intranasally in a lethal hamster model of Nipah virus disease. We demonstrate significantly improved clinical outcomes, including reduction in both lethality and the appearance of clinical signs. This work provides key efficacy data in a robust model of Nipah virus disease to support further development of TIP-mediated treatment against high-consequence viral pathogens.
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Bhat T, Cao A, Yin J. Virus-like Particles: Measures and Biological Functions. Viruses 2022; 14:383. [PMID: 35215979 PMCID: PMC8877645 DOI: 10.3390/v14020383] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 02/10/2022] [Accepted: 02/10/2022] [Indexed: 12/25/2022] Open
Abstract
Virus-like particles resemble infectious virus particles in size, shape, and molecular composition; however, they fail to productively infect host cells. Historically, the presence of virus-like particles has been inferred from total particle counts by microscopy, and infectious particle counts or plaque-forming-units (PFUs) by plaque assay; the resulting ratio of particles-to-PFUs is often greater than one, easily 10 or 100, indicating that most particles are non-infectious. Despite their inability to hijack cells for their reproduction, virus-like particles and the defective genomes they carry can exhibit a broad range of behaviors: interference with normal virus growth during co-infections, cell killing, and activation or inhibition of innate immune signaling. In addition, some virus-like particles become productive as their multiplicities of infection increase, a sign of cooperation between particles. Here, we review established and emerging methods to count virus-like particles and characterize their biological functions. We take a critical look at evidence for defective interfering virus genomes in natural and clinical isolates, and we review their potential as antiviral therapeutics. In short, we highlight an urgent need to better understand how virus-like genomes and particles interact with intact functional viruses during co-infection of their hosts, and their impacts on the transmission, severity, and persistence of virus-associated diseases.
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Affiliation(s)
| | | | - John Yin
- Department of Chemical and Biological Engineering, Wisconsin Institute for Discovery, University of Wisconsin-Madison, 330 N. Orchard Street, Madison, WI 53715, USA; (T.B.); (A.C.)
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13
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Abstract
Defective interfering (DI) genomes restrict viral replication and induce type I interferon. Since DI genomes have been proposed as vaccine adjuvants or therapeutic antiviral agents, it is important to understand their generation, delineate their mechanism of action, develop robust production capacities, assess their safety and in vivo longevity, and determine their long-term effects. To address this, we generated a recombinant canine distemper virus (rCDV) from an entirely synthetic molecular clone designed using the genomic sequence from a clinical isolate obtained from a free-ranging raccoon with distemper. rCDV was serially passaged in vitro to identify DI genomes that naturally arise during rCDV replication. Defective genomes were identified by Sanger and next-generation sequencing techniques, and predominant genomes were synthetically generated and cloned into T7-driven plasmids. Fully encapsidated DI particles (DIPs) were then generated using a rationally attenuated rCDV as a producer virus to drive DI genome replication. We demonstrate that these DIPs interfere with rCDV replication in a dose-dependent manner in vitro. Finally, we show sustained replication of a fluorescent DIP in experimentally infected ferrets over a period of 14 days. Most importantly, DIPs were isolated from the lymphoid tissues, which are a major site of CDV replication. Our established pipeline for detection, generation, and assaying DIPs is transferable to highly pathogenic paramyxoviruses and will allow qualitative and quantitative assessment of the therapeutic effects of DIP administration on disease outcome. IMPORTANCE Defective interfering (DI) genomes have long been considered inconvenient artifacts that suppressed viral replication in vitro. However, advances in sequencing technologies have led to DI genomes being identified in clinical samples, implicating them in disease progression and outcome. It has been suggested that DI genomes might be harnessed therapeutically. Negative-strand RNA virus research has provided a rich pool of natural DI genomes over many years, and they are probably the best understood in vitro. Here, we demonstrate the identification, synthesis, production, and experimental inoculation of novel CDV DI genomes in highly susceptible ferrets. These results provide important evidence that rationally designed and packaged DI genomes can survive the course of a wild-type virus infection.
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14
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López CB. Defective Viral Particles. Virology 2021. [DOI: 10.1002/9781119818526.ch5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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15
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Defective viral genomes as therapeutic interfering particles against flavivirus infection in mammalian and mosquito hosts. Nat Commun 2021; 12:2290. [PMID: 33863888 PMCID: PMC8052367 DOI: 10.1038/s41467-021-22341-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 03/12/2021] [Indexed: 01/13/2023] Open
Abstract
Arthropod-borne viruses pose a major threat to global public health. Thus, innovative strategies for their control and prevention are urgently needed. Here, we exploit the natural capacity of viruses to generate defective viral genomes (DVGs) to their detriment. While DVGs have been described for most viruses, identifying which, if any, can be used as therapeutic agents remains a challenge. We present a combined experimental evolution and computational approach to triage DVG sequence space and pinpoint the fittest deletions, using Zika virus as an arbovirus model. This approach identifies fit DVGs that optimally interfere with wild-type virus infection. We show that the most fit DVGs conserve the open reading frame to maintain the translation of the remaining non-structural proteins, a characteristic that is fundamental across the flavivirus genus. Finally, we demonstrate that the high fitness DVG is antiviral in vivo both in the mammalian host and the mosquito vector, reducing transmission in the latter by up to 90%. Our approach establishes the method to interrogate the DVG fitness landscape, and enables the systematic identification of DVGs that show promise as human therapeutics and vector control strategies to mitigate arbovirus transmission and disease.
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16
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Pei J, Wagner ND, Zou AJ, Chatterjee S, Borek D, Cole AR, Kim PJ, Basler CF, Otwinowski Z, Gross ML, Amarasinghe GK, Leung DW. Structural basis for IFN antagonism by human respiratory syncytial virus nonstructural protein 2. Proc Natl Acad Sci U S A 2021; 118:e2020587118. [PMID: 33649232 PMCID: PMC7958447 DOI: 10.1073/pnas.2020587118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Human respiratory syncytial virus (RSV) nonstructural protein 2 (NS2) inhibits host interferon (IFN) responses stimulated by RSV infection by targeting early steps in the IFN-signaling pathway. But the molecular mechanisms related to how NS2 regulates these processes remain incompletely understood. To address this gap, here we solved the X-ray crystal structure of NS2. This structure revealed a unique fold that is distinct from other known viral IFN antagonists, including RSV NS1. We also show that NS2 directly interacts with an inactive conformation of the RIG-I-like receptors (RLRs) RIG-I and MDA5. NS2 binding prevents RLR ubiquitination, a process critical for prolonged activation of downstream signaling. Structural analysis, including by hydrogen-deuterium exchange coupled to mass spectrometry, revealed that the N terminus of NS2 is essential for binding to the RIG-I caspase activation and recruitment domains. N-terminal mutations significantly diminish RIG-I interactions and result in increased IFNβ messenger RNA levels. Collectively, our studies uncover a previously unappreciated regulatory mechanism by which NS2 further modulates host responses and define an approach for targeting host responses.
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Affiliation(s)
- Jingjing Pei
- John T. Milliken Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO 63110
| | - Nicole D Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110
| | - Angela J Zou
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Srirupa Chatterjee
- John T. Milliken Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO 63110
| | - Dominika Borek
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Aidan R Cole
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Preston J Kim
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Christopher F Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303
| | - Zbyszek Otwinowski
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Daisy W Leung
- John T. Milliken Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO 63110;
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
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17
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Levi LI, Rezelj VV, Henrion-Lacritick A, Erazo D, Boussier J, Vallet T, Bernhauerová V, Suzuki Y, Carrau L, Weger-Lucarelli J, Saleh MC, Vignuzzi M. Defective viral genomes from chikungunya virus are broad-spectrum antivirals and prevent virus dissemination in mosquitoes. PLoS Pathog 2021; 17:e1009110. [PMID: 33556143 PMCID: PMC7870000 DOI: 10.1371/journal.ppat.1009110] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 10/29/2020] [Indexed: 11/19/2022] Open
Abstract
Defective viral genomes (DVGs) are truncated and/or rearranged viral genomes produced during virus replication. Described in many RNA virus families, some of them have interfering activity on their parental virus and/or strong immunostimulatory potential, and are being considered in antiviral approaches. Chikungunya virus (CHIKV) is an alphavirus transmitted by Aedes spp. that infected millions of humans in the last 15 years. Here, we describe the DVGs arising during CHIKV infection in vitro in mammalian and mosquito cells, and in vivo in experimentally infected Aedes aegypti mosquitoes. We combined experimental and computational approaches to select DVG candidates most likely to have inhibitory activity and showed that, indeed, they strongly interfere with CHIKV replication both in mammalian and mosquito cells. We further demonstrated that some DVGs present broad-spectrum activity, inhibiting several CHIKV strains and other alphaviruses. Finally, we showed that pre-treating Aedes aegypti with DVGs prevented viral dissemination in vivo.
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Affiliation(s)
- Laura I. Levi
- Institut Pasteur, Viral Populations and Pathogenesis Unit, CNRS UMR 3569, Paris, France
- École doctorale BioSPC, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Veronica V. Rezelj
- Institut Pasteur, Viral Populations and Pathogenesis Unit, CNRS UMR 3569, Paris, France
| | | | - Diana Erazo
- Institut Pasteur, Viral Populations and Pathogenesis Unit, CNRS UMR 3569, Paris, France
| | - J Boussier
- Institut Pasteur, Viral Populations and Pathogenesis Unit, CNRS UMR 3569, Paris, France
- École doctorale Frontières du vivant, Université Paris Diderot, Paris, France
| | - Thomas Vallet
- Institut Pasteur, Viral Populations and Pathogenesis Unit, CNRS UMR 3569, Paris, France
| | - Veronika Bernhauerová
- Institut Pasteur, Viral Populations and Pathogenesis Unit, CNRS UMR 3569, Paris, France
- Department of Biophysics and Physical Chemistry, Faculty of Pharmacy, Charles University, Hradec Králové, Czech Republic
| | - Yasutsugu Suzuki
- Institut Pasteur, Viruses and RNAi Unit, CNRS UMR 3569, Paris, France
| | - Lucia Carrau
- Institut Pasteur, Viral Populations and Pathogenesis Unit, CNRS UMR 3569, Paris, France
- École doctorale BioSPC, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - James Weger-Lucarelli
- Institut Pasteur, Viral Populations and Pathogenesis Unit, CNRS UMR 3569, Paris, France
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, VA-MD Regional College of Veterinary Medicine, Blacksburg, Virginia, United States of America
| | - Maria-Carla Saleh
- Institut Pasteur, Viruses and RNAi Unit, CNRS UMR 3569, Paris, France
| | - Marco Vignuzzi
- Institut Pasteur, Viral Populations and Pathogenesis Unit, CNRS UMR 3569, Paris, France
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18
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Johnson DM, Cubitt B, Pfeffer TL, de la Torre JC, Lukashevich IS. Lassa Virus Vaccine Candidate ML29 Generates Truncated Viral RNAs Which Contribute to Interfering Activity and Attenuation. Viruses 2021; 13:v13020214. [PMID: 33573250 PMCID: PMC7912207 DOI: 10.3390/v13020214] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/09/2021] [Accepted: 01/26/2021] [Indexed: 01/14/2023] Open
Abstract
Defective interfering particles (DIPs) are naturally occurring products during virus replication in infected cells. DIPs contain defective viral genomes (DVGs) and interfere with replication and propagation of their corresponding standard viral genomes by competing for viral and cellular resources, as well as promoting innate immune antiviral responses. Consequently, for many different viruses, including mammarenaviruses, DIPs play key roles in the outcome of infection. Due to their ability to broadly interfere with viral replication, DIPs are attractive tools for the development of a new generation of biologics to target genetically diverse and rapidly evolving viruses. Here, we provide evidence that in cells infected with the Lassa fever (LF) vaccine candidate ML29, a reassortant that carries the nucleoprotein (NP) and glycoprotein (GP) dominant antigens of the pathogenic Lassa virus (LASV) together with the L polymerase and Z matrix protein of the non-pathogenic genetically related Mopeia virus (MOPV), L-derived truncated RNA species are readily detected following infection at low multiplicity of infection (MOI) or in persistently-infected cells originally infected at high MOI. In the present study, we show that expression of green fluorescent protein (GFP) driven by a tri-segmented form of the mammarenavirus lymphocytic choriomeningitis virus (r3LCMV-GFP/GFP) was strongly inhibited in ML29-persistently infected cells, and that the magnitude of GFP suppression was dependent on the passage history of the ML29-persistently infected cells. In addition, we found that DIP-enriched ML29 was highly attenuated in immunocompetent CBA/J mice and in Hartley guinea pigs. Likewise, STAT-1-/- mice, a validated small animal model for human LF associated hearing loss sequelae, infected with DIP-enriched ML29 did not exhibit any hearing abnormalities throughout the observation period (62 days).
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Affiliation(s)
- Dylan M. Johnson
- Department of Microbiology and Immunology, School of Medicine, University of Louisville, Louisville, KY 40202, USA
- Center for Predictive Medicine for Biodefense and Emerging Infectious diseases, University of Louisville, Louisville, KY 40202, USA;
- Correspondence: (D.M.J.); (I.S.L.)
| | - Beatrice Cubitt
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA; (B.C.); (J.C.d.l.T.)
| | - Tia L. Pfeffer
- Center for Predictive Medicine for Biodefense and Emerging Infectious diseases, University of Louisville, Louisville, KY 40202, USA;
- Department of Pharmacology and Toxicology, School of Medicine, University of Louisville, Louisville, KY 402042, USA
| | - Juan Carlos de la Torre
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA; (B.C.); (J.C.d.l.T.)
| | - Igor S. Lukashevich
- Center for Predictive Medicine for Biodefense and Emerging Infectious diseases, University of Louisville, Louisville, KY 40202, USA;
- Department of Pharmacology and Toxicology, School of Medicine, University of Louisville, Louisville, KY 402042, USA
- Correspondence: (D.M.J.); (I.S.L.)
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19
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Genoyer E, Kulej K, Hung CT, Thibault PA, Azarm K, Takimoto T, Garcia BA, Lee B, Lakdawala S, Weitzman MD, López CB. The Viral Polymerase Complex Mediates the Interaction of Viral Ribonucleoprotein Complexes with Recycling Endosomes during Sendai Virus Assembly. mBio 2020; 11:e02028-20. [PMID: 32843550 PMCID: PMC7448285 DOI: 10.1128/mbio.02028-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 07/23/2020] [Indexed: 11/20/2022] Open
Abstract
Paramyxoviruses are negative-sense single-stranded RNA viruses that comprise many important human and animal pathogens, including human parainfluenza viruses. These viruses bud from the plasma membrane of infected cells after the viral ribonucleoprotein complex (vRNP) is transported from the cytoplasm to the cell membrane via Rab11a-marked recycling endosomes. The viral proteins that are critical for mediating this important initial step in viral assembly are unknown. Here, we used the model paramyxovirus, murine parainfluenza virus 1, or Sendai virus (SeV), to investigate the roles of viral proteins in Rab11a-driven virion assembly. We previously reported that infection with SeV containing high levels of copy-back defective viral genomes (DVGs) (DVG-high SeV) generates heterogenous populations of cells. Cells enriched in full-length (FL) virus produce viral particles containing standard or defective viral genomes, while cells enriched in DVGs do not, despite high levels of defective viral genome replication. Here, we took advantage of this heterogenous cell phenotype to identify proteins that mediate interaction of vRNPs with Rab11a. We examined the roles of matrix protein and nucleoprotein and determined that their presence is not sufficient to drive interaction of vRNPs with recycling endosomes. Using a combination of mass spectrometry and comparative analyses of protein abundance and localization in DVG-high and FL-virus-high (FL-high) cells, we identified viral polymerase complex component protein L and, specifically, its cofactor C as interactors with Rab11a. We found that accumulation of L and C proteins within the cell is the defining feature that differentiates cells that proceed to viral egress from cells containing viruses that remain in replication phases.IMPORTANCE Paramyxoviruses are members of a family of viruses that include a number of pathogens imposing significant burdens on human health. In particular, human parainfluenza viruses are an important cause of pneumonia and bronchiolitis in children for which there are no vaccines or directly acting antivirals. These cytoplasmic replicating viruses bud from the plasma membrane and co-opt cellular endosomal recycling pathways to traffic viral ribonucleoprotein complexes from the cytoplasm to the membrane of infected cells. The viral proteins required for viral engagement with the recycling endosome pathway are still not known. Here, we used the model paramyxovirus Sendai virus, or murine parainfluenza virus 1, to investigate the role of viral proteins in this initial step of viral assembly. We found that the viral polymerase components large protein L and accessory protein C are necessary for engagement with recycling endosomes. These findings are important in identifying viral proteins as potential targets for development of antivirals.
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Affiliation(s)
- Emmanuelle Genoyer
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Katarzyna Kulej
- Division of Protective Immunity and Division of Cancer Pathobiology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Chuan Tien Hung
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Patricia A Thibault
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Kristopher Azarm
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Toru Takimoto
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York, USA
| | - Benjamin A Garcia
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Benhur Lee
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Seema Lakdawala
- Department of Microbiology & Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Matthew D Weitzman
- Division of Protective Immunity and Division of Cancer Pathobiology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Carolina B López
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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20
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Sermersheim M, Kenney AD, Lin PH, McMichael TM, Cai C, Gumpper K, Adesanya TMA, Li H, Zhou X, Park KH, Yount JS, Ma J. MG53 suppresses interferon-β and inflammation via regulation of ryanodine receptor-mediated intracellular calcium signaling. Nat Commun 2020; 11:3624. [PMID: 32681036 PMCID: PMC7368064 DOI: 10.1038/s41467-020-17177-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 06/02/2020] [Indexed: 01/19/2023] Open
Abstract
TRIM family proteins play integral roles in the innate immune response to virus infection. MG53 (TRIM72) is essential for cell membrane repair and is believed to be a muscle-specific TRIM protein. Here we show human macrophages express MG53, and MG53 protein expression is reduced following virus infection. Knockdown of MG53 in macrophages leads to increases in type I interferon (IFN) upon infection. MG53 knockout mice infected with influenza virus show comparable influenza virus titres to wild type mice, but display increased morbidity accompanied by more accumulation of CD45+ cells and elevation of IFNβ in the lung. We find that MG53 knockdown results in activation of NFκB signalling, which is linked to an increase in intracellular calcium oscillation mediated by ryanodine receptor (RyR). MG53 inhibits IFNβ induction in an RyR-dependent manner. This study establishes MG53 as a new target for control of virus-induced morbidity and tissue injury.
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Affiliation(s)
- Matthew Sermersheim
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Adam D Kenney
- Department of Microbial Infection and Immunity, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Pei-Hui Lin
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Temet M McMichael
- Department of Microbial Infection and Immunity, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Chuanxi Cai
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Kristyn Gumpper
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - T M Ayodele Adesanya
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Haichang Li
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Xinyu Zhou
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Ki-Ho Park
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Jacob S Yount
- Department of Microbial Infection and Immunity, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
| | - Jianjie Ma
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
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21
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Welch SR, Tilston NL, Lo MK, Whitmer SLM, Harmon JR, Scholte FEM, Spengler JR, Duprex WP, Nichol ST, Spiropoulou CF. Inhibition of Nipah Virus by Defective Interfering Particles. J Infect Dis 2020; 221:S460-S470. [PMID: 32108876 PMCID: PMC11034736 DOI: 10.1093/infdis/jiz564] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The error-prone nature of RNA-dependent RNA polymerases drives the diversity of RNA virus populations. Arising within this diversity is a subset of defective viral genomes that retain replication competency, termed defective interfering (DI) genomes. These defects are caused by aberrant viral polymerase reinitiation on the same viral RNA template (deletion DI species) or the nascent RNA strand (copyback DI species). DI genomes have previously been shown to alter the dynamics of a viral population by interfering with normal virus replication and/or by stimulating the innate immune response. In this study, we investigated the ability of artificially produced DI genomes to inhibit Nipah virus (NiV), a highly pathogenic biosafety level 4 paramyxovirus. High multiplicity of infection passaging of both NiV clinical isolates and recombinant NiV in Vero cells generated an extensive DI population from which individual DIs were identified using next-generation sequencing techniques. Assays were established to generate and purify both naturally occurring and in silico-designed DIs as fully encapsidated, infectious virus-like particles termed defective interfering particles (DIPs). We demonstrate that several of these NiV DIP candidates reduced NiV titers by up to 4 logs in vitro. These data represent a proof-of-principle that a therapeutic application of DIPs to combat NiV infections may be an alternative source of antiviral control for this disease.
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Affiliation(s)
- Stephen R. Welch
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Natasha L. Tilston
- Center for Vaccine Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Michael K. Lo
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Shannon L. M. Whitmer
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Jessica R. Harmon
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Florine E. M. Scholte
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Jessica R. Spengler
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - W. Paul Duprex
- Center for Vaccine Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Stuart T. Nichol
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Christina F. Spiropoulou
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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22
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Ferren M, Horvat B, Mathieu C. Measles Encephalitis: Towards New Therapeutics. Viruses 2019; 11:E1017. [PMID: 31684034 PMCID: PMC6893791 DOI: 10.3390/v11111017] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/25/2019] [Accepted: 10/31/2019] [Indexed: 12/20/2022] Open
Abstract
Measles remains a major cause of morbidity and mortality worldwide among vaccine preventable diseases. Recent decline in vaccination coverage resulted in re-emergence of measles outbreaks. Measles virus (MeV) infection causes an acute systemic disease, associated in certain cases with central nervous system (CNS) infection leading to lethal neurological disease. Early following MeV infection some patients develop acute post-infectious measles encephalitis (APME), which is not associated with direct infection of the brain. MeV can also infect the CNS and cause sub-acute sclerosing panencephalitis (SSPE) in immunocompetent people or measles inclusion-body encephalitis (MIBE) in immunocompromised patients. To date, cellular and molecular mechanisms governing CNS invasion are still poorly understood. Moreover, the known MeV entry receptors are not expressed in the CNS and how MeV enters and spreads in the brain is not fully understood. Different antiviral treatments have been tested and validated in vitro, ex vivo and in vivo, mainly in small animal models. Most treatments have high efficacy at preventing infection but their effectiveness after CNS manifestations remains to be evaluated. This review describes MeV neural infection and current most advanced therapeutic approaches potentially applicable to treat MeV CNS infection.
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Affiliation(s)
- Marion Ferren
- CIRI, International Center for Infectiology Research, INSERM U1111, University of Lyon, University Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, France.
| | - Branka Horvat
- CIRI, International Center for Infectiology Research, INSERM U1111, University of Lyon, University Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, France.
| | - Cyrille Mathieu
- CIRI, International Center for Infectiology Research, INSERM U1111, University of Lyon, University Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, France.
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23
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Yang Y, Lyu T, Zhou R, He X, Ye K, Xie Q, Zhu L, Chen T, Shen C, Wu Q, Zhang B, Zhao W. The Antiviral and Antitumor Effects of Defective Interfering Particles/Genomes and Their Mechanisms. Front Microbiol 2019; 10:1852. [PMID: 31447826 PMCID: PMC6696905 DOI: 10.3389/fmicb.2019.01852] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 07/26/2019] [Indexed: 12/16/2022] Open
Abstract
Defective interfering particles (DIPs), derived naturally from viral particles, are not able to replicate on their own. Several studies indicate that DIPs exert antiviral effects via multiple mechanisms. DIPs are able to activate immune responses and suppress virus replication cycles, such as competing for viral replication products, impeding the packaging, release and invasion of viruses. Other studies show that DIPs can be used as a vaccine against viral infection. Moreover, DIPs/DI genomes display antitumor effects by inducing tumor cell apoptosis and promoting dendritic cell maturation. With genetic modified techniques, it is possible to improve its safety against both viruses and tumors. In this review, a comprehensive discussion on the effects exerted by DIPs is provided. We further highlight the clinical significance of DIPs and propose that DIPs can open up a new platform for antiviral and antitumor therapies.
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Affiliation(s)
- Yicheng Yang
- Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China.,The First Clinical Medical College, Southern Medical University, Guangzhou, China
| | - Taibiao Lyu
- The First Clinical Medical College, Southern Medical University, Guangzhou, China
| | - Runing Zhou
- The First Clinical Medical College, Southern Medical University, Guangzhou, China
| | - Xiaoen He
- Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Kaiyan Ye
- The Second Clinical Medical College, Southern Medical University, Guangzhou, China
| | - Qian Xie
- Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Li Zhu
- Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Tingting Chen
- Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Chu Shen
- Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Qinghua Wu
- Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Bao Zhang
- Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Wei Zhao
- Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
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24
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Brisse M, Ly H. Comparative Structure and Function Analysis of the RIG-I-Like Receptors: RIG-I and MDA5. Front Immunol 2019; 10:1586. [PMID: 31379819 PMCID: PMC6652118 DOI: 10.3389/fimmu.2019.01586] [Citation(s) in RCA: 218] [Impact Index Per Article: 43.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 06/25/2019] [Indexed: 12/12/2022] Open
Abstract
RIG-I (Retinoic acid-inducible gene I) and MDA5 (Melanoma Differentiation-Associated protein 5), collectively known as the RIG-I-like receptors (RLRs), are key protein sensors of the pathogen-associated molecular patterns (PAMPs) in the form of viral double-stranded RNA (dsRNA) motifs to induce expression of type 1 interferons (IFN1) (IFNα and IFNβ) and other pro-inflammatory cytokines during the early stage of viral infection. While RIG-I and MDA5 share many genetic, structural and functional similarities, there is increasing evidence that they can have significantly different strategies to recognize different pathogens, PAMPs, and in different host species. This review article discusses the similarities and differences between RIG-I and MDA5 from multiple perspectives, including their structures, evolution and functional relationships with other cellular proteins, their differential mechanisms of distinguishing between host and viral dsRNAs and interactions with host and viral protein factors, and their immunogenic signaling. A comprehensive comparative analysis can help inform future studies of RIG-I and MDA5 in order to fully understand their functions in order to optimize potential therapeutic approaches targeting them.
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Affiliation(s)
- Morgan Brisse
- Biochemistry, Molecular Biology, and Biophysics Graduate Program, University of Minnesota, Twin Cities, St. Paul, MN, United States
- Department of Veterinary & Biomedical Sciences, University of Minnesota, Twin Cities, St. Paul, MN, United States
| | - Hinh Ly
- Department of Veterinary & Biomedical Sciences, University of Minnesota, Twin Cities, St. Paul, MN, United States
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25
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Defective viral genomes are key drivers of the virus-host interaction. Nat Microbiol 2019; 4:1075-1087. [PMID: 31160826 PMCID: PMC7097797 DOI: 10.1038/s41564-019-0465-y] [Citation(s) in RCA: 192] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 04/23/2019] [Indexed: 12/12/2022]
Abstract
Viruses survive often harsh host environments, yet we know little about the strategies they utilize to adapt and subsist given their limited genomic resources. We are beginning to appreciate the surprising versatility of viral genomes and how replication-competent and -defective virus variants can provide means for adaptation, immune escape and virus perpetuation. This Review summarizes current knowledge of the types of defective viral genomes generated during the replication of RNA viruses and the functions that they carry out. We highlight the universality and diversity of defective viral genomes during infections and discuss their predicted role in maintaining a fit virus population, their impact on human and animal health, and their potential to be harnessed as antiviral tools. This Review describes recent findings on the biogenesis and the role of defective viral genomes during replication of RNA viruses and discusses their impact on viral dynamics and evolution.
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26
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Abstract
Defective viral genomes (DVGs) are generated during viral replication and are unable to carry out a full replication cycle unless coinfected with a full-length virus. DVGs are produced by many viruses, and their presence correlates with alterations in infection outcomes. Historically, DVGs were studied for their ability to interfere with standard virus replication as well as for their association with viral persistence. More recently, a critical role for DVGs in inducing the innate immune response during infection was appreciated. Here we review the role of DVGs of RNA viruses in shaping outcomes of experimental as well as natural infections and explore the mechanisms by which DVGs impact infection outcome.
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Affiliation(s)
- Emmanuelle Genoyer
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA;
| | - Carolina B López
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA;
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Warmbrod KL, Patterson EI, Kautz TF, Stanton A, Rockx-Brouwer D, Kalveram BK, Khanipov K, Thangamani S, Fofanov Y, Forrester NL. Viral RNA-dependent RNA polymerase mutants display an altered mutation spectrum resulting in attenuation in both mosquito and vertebrate hosts. PLoS Pathog 2019; 15:e1007610. [PMID: 30947291 PMCID: PMC6467425 DOI: 10.1371/journal.ppat.1007610] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 04/16/2019] [Accepted: 01/31/2019] [Indexed: 02/06/2023] Open
Abstract
The presence of bottlenecks in the transmission cycle of many RNA viruses leads to a severe reduction of number of virus particles and this occurs multiple times throughout the viral transmission cycle. Viral replication is then necessary for regeneration of a diverse mutant swarm. It is now understood that any perturbation of the mutation frequency either by increasing or decreasing the accumulation of mutations in an RNA virus results in attenuation of the virus. To determine if altering the rate at which a virus accumulates mutations decreases the probability of a successful virus infection due to issues traversing host bottlenecks, a series of mutations in the RNA-dependent RNA polymerase of Venezuelan equine encephalitis virus (VEEV), strain 68U201, were tested for mutation rate changes. All RdRp mutants were attenuated in both the mosquito and vertebrate hosts, while showing no attenuation during in vitro infections. The rescued viruses containing these mutations showed some evidence of change in fidelity, but the phenotype was not sustained following passaging. However, these mutants did exhibit changes in the frequency of specific types of mutations. Using a model of mutation production, these changes were shown to decrease the number of stop codons generated during virus replication. This suggests that the observed mutant attenuation in vivo may be due to an increase in the number of unfit genomes, which may be normally selected against by the accumulation of stop codons. Lastly, the ability of these attenuated viruses to transition through a bottleneck in vivo was measured using marked virus clones. The attenuated viruses showed an overall reduction in the number of marked clones for both the mosquito and vertebrate hosts, as well as a reduced ability to overcome the known bottlenecks in the mosquito. This study demonstrates that any perturbation of the optimal mutation frequency whether through changes in fidelity or by alterations in the mutation frequency of specific nucleotides, has significant deleterious effects on the virus, especially in the presence of host bottlenecks.
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Affiliation(s)
- K. Lane Warmbrod
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Edward I. Patterson
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Tiffany F. Kautz
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Adam Stanton
- School of Computing and Mathematics, University of Keele, Keele, United Kingdom
| | - Dedeke Rockx-Brouwer
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Birte K. Kalveram
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Kamil Khanipov
- Sealy Center for Structural Biology and Molecular Biophysics, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Saravanan Thangamani
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Yuriy Fofanov
- Sealy Center for Structural Biology and Molecular Biophysics, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Naomi L. Forrester
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
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Rezelj VV, Levi LI, Vignuzzi M. The defective component of viral populations. Curr Opin Virol 2018; 33:74-80. [PMID: 30099321 DOI: 10.1016/j.coviro.2018.07.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/16/2018] [Accepted: 07/21/2018] [Indexed: 01/22/2023]
Abstract
Particles containing degenerate forms of the viral genome which interfere with virus replication and are non-replicative per se are known as defective interfering particles (DIPs). DIPs are likely to be produced upon infection by any virus in vitro and in nature. Until recently, roles of these non-viable particles as members of a multi-component viral system have been overlooked. In this review, we cover the most recent studies that shed light on critical roles of DIPs during the course of infection, including: the modulation of virus replication, innate immune responses, disease outcome and virus persistence, as well as the evolution of the viral population. Together, these reports allow us to conceive a more complete picture of the virion population, and highlight the fact that DIPs are not a negligible subset of this population but instead can greatly influence the fate of infection.
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Affiliation(s)
- Veronica V Rezelj
- Unité Populations virales et pathogenèse, Institut Pasteur, Paris, France
| | - Laura I Levi
- Unité Populations virales et pathogenèse, Institut Pasteur, Paris, France
| | - Marco Vignuzzi
- Unité Populations virales et pathogenèse, Institut Pasteur, Paris, France.
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29
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Manzoni TB, López CB. Defective (interfering) viral genomes re-explored: impact on antiviral immunity and virus persistence. Future Virol 2018; 13:493-503. [PMID: 30245734 PMCID: PMC6136085 DOI: 10.2217/fvl-2018-0021] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 05/03/2018] [Indexed: 11/21/2022]
Abstract
Defective viral genomes (DVGs) are natural products of virus replication that occur in many positive and negative sense RNA viruses, including Ebola, dengue and respiratory syncytial virus. DVGs, which have severe genomic truncations and require a helper virus to replicate, have three well-described functions: interference with standard virus replication, immunostimulation, and establishment of virus persistence. These functions of DVGs were first described almost 50 years ago, yet only recent studies have shown the molecular intersection between their immunostimulatory and pro-persistence activities. Here, we review more than half a century of scientific literature on the immunostimulatory and pro-persistence functions of DVGs. We highlight recent advances in the field and the critical role DVGs have in both the acute and long-term virus-host interactions.
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Affiliation(s)
- Tomaz B Manzoni
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Carolina B López
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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30
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Suslov A, Boldanova T, Wang X, Wieland S, Heim MH. Hepatitis B Virus Does Not Interfere With Innate Immune Responses in the Human Liver. Gastroenterology 2018; 154:1778-1790. [PMID: 29408639 DOI: 10.1053/j.gastro.2018.01.034] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 01/17/2018] [Accepted: 01/20/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Most viruses are detected at early stages of cell infection and induce an innate immune response mediated by production of interferons (IFNs). IFNs induce expression of hundreds of IFN-stimulated genes (ISGs). Infection of chimpanzees with hepatitis C virus, but not hepatitis B virus (HBV), induces ISG expression in the liver. HBV might not induce an innate immune response because it is not detected by pattern recognition receptors (the stealth properties of HBV) or because HBV suppresses IFN production or signaling despite detection by pattern recognition receptors. We studied innate immune signaling in liver biopsies from patients with different stages of chronic HBV infection and uninfected individuals (controls). METHODS We obtained liver within 10 minutes after collection from 30 patients with chronic HBV infection (hepatitis B e antigen-positive or -negative, with or without hepatitis) and 42 controls (most with fatty liver disease). The liver tissues were analyzed by histology, immunohistochemistry, quantitative reverse-transcription polymerase chain reaction, in situ hybridization, HBV RNA quantification, and HBV genotyping; some specimens were incubated with toll-like receptor (TLR) ligands (polyinosinic-polycytidylic acid) or infected with Sendai virus and then analyzed. RESULTS Liver specimens from patients with HBV infection were not expressing more IFN or ISGs than those from control patients, indicating that chronic HBV infection did not activate an innate immune response. However, liver specimens from patients with HBV infection did produce IFN and induce expression of ISGs following activation of TLR3 with poly(I:C) or Sendai virus infections, so the innate immune response is not suppressed in these tissues. CONCLUSION Liver tissues from patients with chronic HBV infection do not have induction of an innate immune response, but this response can be activated by other factors (TLR3 binding, Sendai virus infection) in HBV-infected liver tissue. These findings support the hypothesis that HBV is invisible to pattern recognition receptors.
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Affiliation(s)
- Aleksei Suslov
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Tujana Boldanova
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland; Division of Gastroenterology and Hepatology, University Hospital Basel, Basel, Switzerland
| | - Xueya Wang
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Stefan Wieland
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland.
| | - Markus H Heim
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland; Division of Gastroenterology and Hepatology, University Hospital Basel, Basel, Switzerland.
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31
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Yoshida A, Kawabata R, Honda T, Sakai K, Ami Y, Sakaguchi T, Irie T. A Single Amino Acid Substitution within the Paramyxovirus Sendai Virus Nucleoprotein Is a Critical Determinant for Production of Interferon-Beta-Inducing Copyback-Type Defective Interfering Genomes. J Virol 2018; 92:e02094-17. [PMID: 29237838 PMCID: PMC5809723 DOI: 10.1128/jvi.02094-17] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 12/06/2017] [Indexed: 12/12/2022] Open
Abstract
One of the first defenses against infecting pathogens is the innate immune system activated by cellular recognition of pathogen-associated molecular patterns (PAMPs). Although virus-derived RNA species, especially copyback (cb)-type defective interfering (DI) genomes, have been shown to serve as real PAMPs, which strongly induce interferon-beta (IFN-β) during mononegavirus infection, the mechanisms underlying DI generation remain unclear. Here, for the first time, we identified a single amino acid substitution causing production of cbDI genomes by successful isolation of two distinct types of viral clones with cbDI-producing and cbDI-nonproducing phenotypes from the stock Sendai virus (SeV) strain Cantell, which has been widely used in a number of studies on antiviral innate immunity as a representative IFN-β-inducing virus. IFN-β induction was totally dependent on the presence of a significant amount of cbDI genome-containing viral particles (DI particles) in the viral stock, but not on deficiency of the IFN-antagonistic viral accessory proteins C and V. Comparison of the isolates indicated that a single amino acid substitution found within the N protein of the cbDI-producing clone was enough to cause the emergence of DI genomes. The mutated N protein of the cbDI-producing clone resulted in a lower density of nucleocapsids than that of the DI-nonproducing clone, probably causing both production of the DI genomes and their formation of a stem-loop structure, which serves as an ideal ligand for RIG-I. These results suggested that the integrity of mononegaviral nucleocapsids might be a critical factor in avoiding the undesirable recognition of infection by host cells.IMPORTANCE The type I interferon (IFN) system is a pivotal defense against infecting RNA viruses that is activated by sensing viral RNA species. RIG-I is a major sensor for infection with most mononegaviruses, and copyback (cb)-type defective interfering (DI) genomes have been shown to serve as strong RIG-I ligands in real infections. However, the mechanism underlying production of cbDI genomes remains unclear, although DI genomes emerge as the result of an error during viral replication with high doses of viruses. Sendai virus has been extensively studied and is unique in that its interaction with innate immunity reveals opposing characteristics, such as high-level IFN-β induction and strong inhibition of type I IFN pathways. Our findings provide novel insights into the mechanism of production of mononegaviral cbDI genomes, as well as virus-host interactions during innate immunity.
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Affiliation(s)
- Asuka Yoshida
- Department of Virology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Ryoko Kawabata
- Department of Virology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Tomoyuki Honda
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Kouji Sakai
- Department of Virology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yasushi Ami
- Division of Experimental Animal Research, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takemasa Sakaguchi
- Department of Virology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Takashi Irie
- Department of Virology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
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32
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Poirier EZ, Goic B, Tomé-Poderti L, Frangeul L, Boussier J, Gausson V, Blanc H, Vallet T, Loyd H, Levi LI, Lanciano S, Baron C, Merkling SH, Lambrechts L, Mirouze M, Carpenter S, Vignuzzi M, Saleh MC. Dicer-2-Dependent Generation of Viral DNA from Defective Genomes of RNA Viruses Modulates Antiviral Immunity in Insects. Cell Host Microbe 2018; 23:353-365.e8. [PMID: 29503180 PMCID: PMC5857290 DOI: 10.1016/j.chom.2018.02.001] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 11/08/2017] [Accepted: 02/07/2018] [Indexed: 12/21/2022]
Abstract
The RNAi pathway confers antiviral immunity in insects. Virus-specific siRNA responses are amplified via the reverse transcription of viral RNA to viral DNA (vDNA). The nature, biogenesis, and regulation of vDNA are unclear. We find that vDNA produced during RNA virus infection of Drosophila and mosquitoes is present in both linear and circular forms. Circular vDNA (cvDNA) is sufficient to produce siRNAs that confer partially protective immunity when challenged with a cognate virus. cvDNAs bear homology to defective viral genomes (DVGs), and DVGs serve as templates for vDNA and cvDNA synthesis. Accordingly, DVGs promote the amplification of vDNA-mediated antiviral RNAi responses in infected Drosophila. Furthermore, vDNA synthesis is regulated by the DExD/H helicase domain of Dicer-2 in a mechanism distinct from its role in siRNA generation. We suggest that, analogous to mammalian RIG-I-like receptors, Dicer-2 functions like a pattern recognition receptor for DVGs to modulate antiviral immunity in insects.
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Affiliation(s)
- Enzo Z Poirier
- Institut Pasteur, Viruses and RNA Interference, Centre National de la Recherche Scientifique UMR 3569, 75015 Paris, France; Institut Pasteur, Viral Populations and Pathogenesis, Centre National de la Recherche Scientifique UMR 3569, 75015 Paris, France; University of Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur, 75013 Paris, France
| | - Bertsy Goic
- Institut Pasteur, Viruses and RNA Interference, Centre National de la Recherche Scientifique UMR 3569, 75015 Paris, France
| | - Lorena Tomé-Poderti
- Institut Pasteur, Viruses and RNA Interference, Centre National de la Recherche Scientifique UMR 3569, 75015 Paris, France
| | - Lionel Frangeul
- Institut Pasteur, Viruses and RNA Interference, Centre National de la Recherche Scientifique UMR 3569, 75015 Paris, France
| | - Jérémy Boussier
- Institut Pasteur, Immunobiology of Dendritic Cells, Institut National de la Santé et de la Recherche Médicale, U1223, 75015 Paris, France
| | - Valérie Gausson
- Institut Pasteur, Viruses and RNA Interference, Centre National de la Recherche Scientifique UMR 3569, 75015 Paris, France
| | - Hervé Blanc
- Institut Pasteur, Viruses and RNA Interference, Centre National de la Recherche Scientifique UMR 3569, 75015 Paris, France; Institut Pasteur, Viral Populations and Pathogenesis, Centre National de la Recherche Scientifique UMR 3569, 75015 Paris, France
| | - Thomas Vallet
- Institut Pasteur, Viral Populations and Pathogenesis, Centre National de la Recherche Scientifique UMR 3569, 75015 Paris, France
| | - Hyelee Loyd
- Department of Animal Science, Iowa State University, Ames, IA 50010, USA
| | - Laura I Levi
- Institut Pasteur, Viral Populations and Pathogenesis, Centre National de la Recherche Scientifique UMR 3569, 75015 Paris, France
| | - Sophie Lanciano
- Institut de Recherche pour le Développement, DIADE, Université de Montpellier, Université de Perpignan, LGDP, 66860 Perpignan, France
| | - Chloé Baron
- Institut Pasteur, Viruses and RNA Interference, Centre National de la Recherche Scientifique UMR 3569, 75015 Paris, France
| | - Sarah H Merkling
- Institut Pasteur, Insect-Virus Interactions, Centre National de la Recherche Scientifique URA 3012, 75015 Paris, France
| | - Louis Lambrechts
- Institut Pasteur, Insect-Virus Interactions, Centre National de la Recherche Scientifique URA 3012, 75015 Paris, France
| | - Marie Mirouze
- Institut de Recherche pour le Développement, DIADE, Université de Montpellier, Université de Perpignan, LGDP, 66860 Perpignan, France
| | - Susan Carpenter
- Department of Animal Science, Iowa State University, Ames, IA 50010, USA
| | - Marco Vignuzzi
- Institut Pasteur, Viral Populations and Pathogenesis, Centre National de la Recherche Scientifique UMR 3569, 75015 Paris, France.
| | - Maria-Carla Saleh
- Institut Pasteur, Viruses and RNA Interference, Centre National de la Recherche Scientifique UMR 3569, 75015 Paris, France.
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Vasou A, Sultanoglu N, Goodbourn S, Randall RE, Kostrikis LG. Targeting Pattern Recognition Receptors (PRR) for Vaccine Adjuvantation: From Synthetic PRR Agonists to the Potential of Defective Interfering Particles of Viruses. Viruses 2017; 9:v9070186. [PMID: 28703784 PMCID: PMC5537678 DOI: 10.3390/v9070186] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 07/11/2017] [Accepted: 07/11/2017] [Indexed: 12/13/2022] Open
Abstract
Modern vaccinology has increasingly focused on non-living vaccines, which are more stable than live-attenuated vaccines but often show limited immunogenicity. Immunostimulatory substances, known as adjuvants, are traditionally used to increase the magnitude of protective adaptive immunity in response to a pathogen-associated antigen. Recently developed adjuvants often include substances that stimulate pattern recognition receptors (PRRs), essential components of innate immunity required for the activation of antigen-presenting cells (APCs), which serve as a bridge between innate and adaptive immunity. Nearly all PRRs are potential targets for adjuvants. Given the recent success of toll-like receptor (TLR) agonists in vaccine development, molecules with similar, but additional, immunostimulatory activity, such as defective interfering particles (DIPs) of viruses, represent attractive candidates for vaccine adjuvants. This review outlines some of the recent advances in vaccine development related to the use of TLR agonists, summarizes the current knowledge regarding DIP immunogenicity, and discusses the potential applications of DIPs in vaccine adjuvantation.
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Affiliation(s)
- Andri Vasou
- Department of Biological Sciences, University of Cyprus, 1 University Avenue, Aglatzia, Nicosia 2109, Cyprus.
| | - Nazife Sultanoglu
- Department of Biological Sciences, University of Cyprus, 1 University Avenue, Aglatzia, Nicosia 2109, Cyprus.
| | - Stephen Goodbourn
- Institute for Infection and Immunity, St George's, University of London, London SW17 0RE, UK.
| | - Richard E Randall
- School of Biology, University of St Andrews, The North Haugh, St Andrews KY16 9ST, UK.
| | - Leondios G Kostrikis
- Department of Biological Sciences, University of Cyprus, 1 University Avenue, Aglatzia, Nicosia 2109, Cyprus.
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Poirier EZ, Vignuzzi M. Virus population dynamics during infection. Curr Opin Virol 2017; 23:82-87. [PMID: 28456056 DOI: 10.1016/j.coviro.2017.03.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/23/2017] [Accepted: 03/24/2017] [Indexed: 12/14/2022]
Abstract
During RNA virus infection of a host, error-prone viral replication will give rise to a cloud of genetically-linked mutants, as well as truncated, defective genomes. In this review, we describe the dynamics of viral diversity during infection, illustrating that the viral population fluctuates greatly in number of genomes and composition of mutants, in relation with the existence of physical barriers or immune pressures. We illustrate the importance of generating diversity by analyzing the case of fidelity variants, largely attenuated in vivo. Recombination is also considered in its various roles: redistribution of mutations on full-length genomes, and production of highly-immunostimulatory defective genomes. We cover these notions by underlining, when they exist, the differences between acute and persistent infections.
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Affiliation(s)
- Enzo Z Poirier
- Institut Pasteur, Centre National de la Recherche Scientifique, UMR 3569, Paris, France; University of Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur, Paris, France
| | - Marco Vignuzzi
- Institut Pasteur, Centre National de la Recherche Scientifique, UMR 3569, Paris, France.
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35
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The innate immune response to RSV: Advances in our understanding of critical viral and host factors. Vaccine 2016; 35:481-488. [PMID: 27686836 DOI: 10.1016/j.vaccine.2016.09.030] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 08/30/2016] [Accepted: 09/15/2016] [Indexed: 12/14/2022]
Abstract
Respiratory syncytial virus (RSV) causes mild to severe respiratory illness in humans and is a major cause of hospitalizations of infants and the elderly. Both the innate and the adaptive immune responses contribute to the control of RSV infection, but despite successful viral clearance, protective immunity against RSV re-infection is usually suboptimal and infections recur. Poor understanding of the mechanisms limiting the induction of long-lasting immunity has delayed the development of an effective vaccine. The innate immune response plays a critical role in driving the development of adaptive immunity and is thus a crucial determinant of the infection outcome. Advances in recent years have improved our understanding of cellular and viral factors that influence the onset and quality of the innate immune response to RSV. These advances include the identification of a complex system of cellular sensors that mediate RSV detection and stimulate transcriptome changes that lead to virus control and the discovery that cell stress and apoptosis participate in the control of RSV infection. In addition, it was recently demonstrated that defective viral genomes (DVGs) generated during RSV replication are the primary inducers of the innate immune response. Newly discovered host pathways involved in the innate response to RSV, together with the potential generation of DVG-derived oligonucleotides, present various novel opportunities for the design of vaccine adjuvants able to induce a protective response against RSV and similar viruses.
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36
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Ho TH, Kew C, Lui PY, Chan CP, Satoh T, Akira S, Jin DY, Kok KH. PACT- and RIG-I-Dependent Activation of Type I Interferon Production by a Defective Interfering RNA Derived from Measles Virus Vaccine. J Virol 2016; 90:1557-68. [PMID: 26608320 PMCID: PMC4719617 DOI: 10.1128/jvi.02161-15] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 11/17/2015] [Indexed: 12/25/2022] Open
Abstract
UNLABELLED The live attenuated measles virus vaccine is highly immunostimulatory. Identification and characterization of its components that activate the innate immune response might provide new strategies and agents for the rational design and development of chemically defined adjuvants. In this study, we report on the activation of type I interferon (IFN) production by a defective interfering (DI) RNA isolated from the Hu-191 vaccine strain of measles virus. We found that the Hu-191 virus induced IFN-β much more potently than the Edmonston strain. In the search for IFN-inducing species in Hu-191, we identified a DI RNA specifically expressed by this strain. This DI RNA, which was of the copy-back type, was predicted to fold into a hairpin structure with a long double-stranded stem region of 206 bp, and it potently induced the expression of IFN-β. Its IFN-β-inducing activity was further enhanced when both cytoplasmic RNA sensor RIG-I and its partner, PACT, were overexpressed. On the contrary, this activity was abrogated in cells deficient in PACT or RIG-I. The DI RNA was found to be associated with PACT in infected cells. In addition, both the 5'-di/triphosphate end and the double-stranded stem region on the DI RNA were essential for its activation of PACT and RIG-I. Taken together, our findings support a model in which a viral DI RNA is sensed by PACT and RIG-I to initiate an innate antiviral response. Our work might also provide a foundation for identifying physiological PACT ligands and developing novel adjuvants or antivirals. IMPORTANCE The live attenuated measles virus vaccine is one of the most successful human vaccines and has largely contained the devastating impact of a highly contagious virus. Identifying the components in this vaccine that stimulate the host immune response and understanding their mechanism of action might help to design and develop better adjuvants, vaccines, antivirals, and immunotherapeutic agents. We identified and characterized a defective interfering RNA from the Hu-191 vaccine strain of measles virus which has safely been used in millions of people for many years. We further demonstrated that this RNA potently induces an antiviral immune response through cellular sensors of viral RNA known as PACT and RIG-I. Similar types of viral RNA that bind with and activate PACT and RIG-I might retain the immunostimulatory property of measles virus vaccines but would not induce adaptive immunity. They are potentially useful as chemically defined vaccine adjuvants, antivirals, and immunostimulatory agents.
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Affiliation(s)
- Ting-Hin Ho
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Chun Kew
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Pak-Yin Lui
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Chi-Ping Chan
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Takashi Satoh
- Department of Host Defense, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Shizuo Akira
- Department of Host Defense, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Dong-Yan Jin
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Kin-Hang Kok
- Department of Microbiology, The University of Hong Kong, Pokfulam, Hong Kong
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Low-Fidelity Polymerases of Alphaviruses Recombine at Higher Rates To Overproduce Defective Interfering Particles. J Virol 2015; 90:2446-54. [PMID: 26676773 PMCID: PMC4810721 DOI: 10.1128/jvi.02921-15] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 12/08/2015] [Indexed: 01/20/2023] Open
Abstract
Low-fidelity RNA-dependent RNA polymerases for many RNA virus mutators have been shown to confer attenuated phenotypes, presumably due to increased mutation rates. Additionally, for many RNA viruses, replication to high titers results in the production of defective interfering particles (DIs) that also attenuate infection. We hypothesized that fidelity, recombination, and DI production are tightly linked. We show that a Sindbis virus mutator replicating at a high multiplicity of infection manifests an earlier and greater accumulation of DIs than its wild-type counterpart. The isolated DIs interfere with the replication of full-length virus in a dose-dependent manner. Importantly, the ability of the mutator virus to overproduce DIs could be linked to an increased recombination frequency. These data confirm that RNA-dependent RNA polymerase fidelity and recombination are inversely correlated for this mutator. Our findings suggest that defective interference resulting from higher recombination rates may be more detrimental to RNA virus mutators than the increase in mutational burden. IMPORTANCE Replication, adaptation, and evolution of RNA viruses rely in large part on their low-fidelity RNA-dependent RNA polymerase. Viruses artificially modified in their polymerases to decrease fidelity (mutator viruses) are attenuated in vivo, demonstrating the important role of fidelity in viral fitness. However, attenuation was attributed solely to the modification of the viral mutation rate and the accumulation of detrimental point mutations. In this work, we described an additional phenotype of mutator viruses: an increased recombination rate leading to defective interfering particle (DI) overproduction. Because DIs are known for their inhibitory effect on viral replication, our work suggests that fidelity variants may be attenuated in vivo via several mechanisms. This has important implications in the development of fidelity variants as live attenuated vaccine strains.
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Xu J, Mercado-López X, Grier JT, Kim WK, Chun LF, Irvine EB, Del Toro Duany Y, Kell A, Hur S, Gale M, Raj A, López CB. Identification of a Natural Viral RNA Motif That Optimizes Sensing of Viral RNA by RIG-I. mBio 2015; 6:e01265-15. [PMID: 26443454 PMCID: PMC4611036 DOI: 10.1128/mbio.01265-15] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 09/11/2015] [Indexed: 12/25/2022] Open
Abstract
UNLABELLED Stimulation of the antiviral response depends on the sensing of viral pathogen-associated molecular patterns (PAMPs) by specialized cellular proteins. During infection with RNA viruses, 5'-di- or -triphosphates accompanying specific single or double-stranded RNA motifs trigger signaling of intracellular RIG-I-like receptors (RLRs) and initiate the antiviral response. Although these molecular signatures are present during the replication of many viruses, it is unknown whether they are sufficient for strong activation of RLRs during infection. Immunostimulatory defective viral genomes (iDVGs) from Sendai virus (SeV) are among the most potent natural viral triggers of antiviral immunity. Here we describe an RNA motif (DVG(70-114)) that is essential for the potent immunostimulatory activity of 5'-triphosphate-containing SeV iDVGs. DVG(70-114) enhances viral sensing by the host cell independently of the long stretches of complementary RNA flanking the iDVGs, and it retains its stimulatory potential when transferred to otherwise inert viral RNA. In vitro analysis showed that DVG(70-114) augments the binding of RIG-I to viral RNA and promotes enhanced RIG-I polymerization, thereby facilitating the onset of the antiviral response. Together, our results define a new natural viral PAMP enhancer motif that promotes viral recognition by RLRs and confers potent immunostimulatory activity to viral RNA. IMPORTANCE A discrete group of molecular motifs, including 5'-triphosphates associated with double-stranded RNA, have been identified as essential for the triggering of antiviral immunity. Most RNA viruses expose these motifs during their replication; however, successful viruses normally evade immune recognition and replicate to high levels before detection, indicating that unknown factors drive antiviral immunity. DVGs from SeV are among the most potent natural viral stimuli of the antiviral response known to date. These studies define a new natural viral motif present in DVGs that maximizes viral recognition by the intracellular sensor RIG-I, allowing fast and strong antiviral responses even in the presence of viral-encoded immune antagonists. This motif can be harnessed to increase the immunostimulatory potential of otherwise inert viral RNAs and represents a novel immunostimulatory enhancer that could be used in the development of vaccine adjuvants and antivirals.
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Affiliation(s)
- Jie Xu
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Xiomara Mercado-López
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jennifer T Grier
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Won-keun Kim
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Lauren F Chun
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Edward B Irvine
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Yoandris Del Toro Duany
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA
| | - Alison Kell
- Department of Immunology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Sun Hur
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA
| | - Michael Gale
- Department of Immunology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Arjun Raj
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Carolina B López
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Sun Y, Jain D, Koziol-White CJ, Genoyer E, Gilbert M, Tapia K, Panettieri RA, Hodinka RL, López CB. Immunostimulatory Defective Viral Genomes from Respiratory Syncytial Virus Promote a Strong Innate Antiviral Response during Infection in Mice and Humans. PLoS Pathog 2015; 11:e1005122. [PMID: 26336095 PMCID: PMC4559413 DOI: 10.1371/journal.ppat.1005122] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 08/02/2015] [Indexed: 01/08/2023] Open
Abstract
Human respiratory syncytial virus (RSV) is a major cause of severe respiratory illness in children and susceptible adults. RSV blocks the development of the innate antiviral immune response and can grow to high titers in the respiratory tract. Here we demonstrate that immunostimulatory defective viral genomes (iDVGs) that are naturally generated during RSV replication are strong inducers of the innate antiviral response to RSV in mice and humans. In mice, RSV iDVGs stimulated the expression of antiviral genes, restricted viral replication, and prevented weight loss and lung inflammation. In human cells, the antiviral response to RSV iDVGs was dominated by the expression of IFN-λ1 over IFN-β and was driven by rapid intranuclear accumulation of the transcription factor IRF1. RSV iDVGs were detected in respiratory secretions of hospitalized patients, and their amount positively correlated with the level of expression of antiviral genes in the samples. Infection of explanted human lung tissue from different donors revealed that most humans can respond to RSV iDVGs and that the rate of accumulation of iDVGs during infection directly correlates with the quality of the antiviral response. Taken together, our data establish iDVGs as primary triggers of robust antiviral responses to RSV and provide the first evidence for an important biological role for naturally occurring iDVGs during a paramyxovirus infection in humans.
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Affiliation(s)
- Yan Sun
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Deepika Jain
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Cynthia J. Koziol-White
- Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Emmanuelle Genoyer
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Micah Gilbert
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Karla Tapia
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Reynold A. Panettieri
- Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Richard L. Hodinka
- Department of Pathology and Laboratory of Medicine, Perelman School of Medicine at the University of Pennsylvania and Clinical Virology Laboratory, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Carolina B. López
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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Dimmock NJ, Easton AJ. Cloned Defective Interfering Influenza RNA and a Possible Pan-Specific Treatment of Respiratory Virus Diseases. Viruses 2015; 7:3768-88. [PMID: 26184282 PMCID: PMC4517125 DOI: 10.3390/v7072796] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Revised: 06/27/2015] [Accepted: 07/03/2015] [Indexed: 12/24/2022] Open
Abstract
Defective interfering (DI) genomes are characterised by their ability to interfere with the replication of the virus from which they were derived, and other genetically compatible viruses. DI genomes are synthesized by nearly all known viruses and represent a vast natural reservoir of antivirals that can potentially be exploited for use in the clinic. This review describes the application of DI virus to protect from virus-associated diseases in vivo using as an example a highly active cloned influenza A DI genome and virus that protects broadly in preclinical trials against different subtypes of influenza A and against non-influenza A respiratory viruses. This influenza A-derived DI genome protects by two totally different mechanisms: molecular interference with influenza A replication and by stimulating innate immunity that acts against non-influenza A viruses. The review considers what is needed to develop DI genomes to the point of entry into clinical trials.
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Affiliation(s)
- Nigel J Dimmock
- School of Life Sciences, University of Warwick, Coventry CV4-7AL, UK.
| | - Andrew J Easton
- School of Life Sciences, University of Warwick, Coventry CV4-7AL, UK.
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Benitez AA, Panis M, Xue J, Varble A, Shim JV, Frick AL, López CB, Sachs D, tenOever BR. In Vivo RNAi Screening Identifies MDA5 as a Significant Contributor to the Cellular Defense against Influenza A Virus. Cell Rep 2015; 11:1714-26. [PMID: 26074083 DOI: 10.1016/j.celrep.2015.05.032] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 02/09/2015] [Accepted: 05/18/2015] [Indexed: 11/15/2022] Open
Abstract
Responding to an influenza A virus (IAV) infection demands an effective intrinsic cellular defense strategy to slow replication. To identify contributing host factors to this defense, we exploited the host microRNA pathway to perform an in vivo RNAi screen. To this end, IAV, lacking a functional NS1 antagonist, was engineered to encode individual siRNAs against antiviral host genes in an effort to rescue attenuation. This screening platform resulted in the enrichment of strains targeting virus-activated transcription factors, specific antiviral effectors, and intracellular pattern recognition receptors (PRRs). Interestingly, in addition to RIG-I, the PRR for IAV, a virus with the capacity to silence MDA5 also emerged as a dominant strain in wild-type, but not in MDA5-deficient mice. Transcriptional profiling of infected knockout cells confirmed RIG-I to be the primary PRR for IAV but implicated MDA5 as a significant contributor to the cellular defense against influenza A virus.
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Affiliation(s)
- Asiel A Benitez
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Maryline Panis
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jia Xue
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Andrew Varble
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jaehee V Shim
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Amy L Frick
- Department of Neurosciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Carolina B López
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David Sachs
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Benjamin R tenOever
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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Lyons C, Fernandes P, Fanning LJ, Houston A, Brint E. Engagement of Fas on Macrophages Modulates Poly I:C induced cytokine production with specific enhancement of IP-10. PLoS One 2015; 10:e0123635. [PMID: 25849666 PMCID: PMC4388479 DOI: 10.1371/journal.pone.0123635] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 02/27/2015] [Indexed: 12/24/2022] Open
Abstract
Viral double-stranded RNA (dsRNA) is recognised by pathogen recognition receptors such as Toll-Like Receptor 3 (TLR3) and retinoic acid inducible gene-I (RIG-I), and results in cytokine and interferon production. Fas, a well characterised death receptor, has recently been shown to play a role in the inflammatory response. In this study we investigated the role of Fas in the anti-viral immune response. Stimulation of Fas on macrophages did not induce significant cytokine production. However, activation of Fas modified the response of macrophages to the viral dsRNA analogue poly I:C. In particular, poly I:C-induced IP-10 production was significantly enhanced. A similar augmentation of IP-10 by Fas was observed following stimulation with both poly A:U and Sendai virus. Fas activation suppressed poly I:C-induced phosphorylation of the MAP kinases p38 and JNK, while overexpression of the Fas adaptor protein, Fas-associated protein with death domain (FADD), activated AP-1 and inhibited poly I:C-induced IP-10 production. Consistent with an inhibitory role for AP-1 in IP-10 production, mutation of the AP-1 binding site on the IP-10 promoter resulted in augmented poly I:C-induced IP-10. These results demonstrate that engagement of the Fas receptor plays a role in modifying the innate immune response to viral RNA.
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Affiliation(s)
- Caitriona Lyons
- Department of Pathology, University College Cork, Cork, Ireland
| | | | - Liam J. Fanning
- Department of Medicine, University College Cork, Cork, Ireland
| | - Aileen Houston
- Department of Medicine, University College Cork, Cork, Ireland
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
- * E-mail:
| | - Elizabeth Brint
- Department of Pathology, University College Cork, Cork, Ireland
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
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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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Chesarino NM, Hach JC, Chen JL, Zaro BW, Rajaram MV, Turner J, Schlesinger LS, Pratt MR, Hang HC, Yount JS. Chemoproteomics reveals Toll-like receptor fatty acylation. BMC Biol 2014; 12:91. [PMID: 25371237 PMCID: PMC4240870 DOI: 10.1186/s12915-014-0091-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 10/20/2014] [Indexed: 01/01/2023] Open
Abstract
Background Palmitoylation is a 16-carbon lipid post-translational modification that increases protein hydrophobicity. This form of protein fatty acylation is emerging as a critical regulatory modification for multiple aspects of cellular interactions and signaling. Despite recent advances in the development of chemical tools for the rapid identification and visualization of palmitoylated proteins, the palmitoyl proteome has not been fully defined. Here we sought to identify and compare the palmitoylated proteins in murine fibroblasts and dendritic cells. Results A total of 563 putative palmitoylation substrates were identified, more than 200 of which have not been previously suggested to be palmitoylated in past proteomic studies. Here we validate the palmitoylation of several new proteins including Toll-like receptors (TLRs) 2, 5 and 10, CD80, CD86, and NEDD4. Palmitoylation of TLR2, which was uniquely identified in dendritic cells, was mapped to a transmembrane domain-proximal cysteine. Inhibition of TLR2 S-palmitoylation pharmacologically or by cysteine mutagenesis led to decreased cell surface expression and a decreased inflammatory response to microbial ligands. Conclusions This work identifies many fatty acylated proteins involved in fundamental cellular processes as well as cell type-specific functions, highlighting the value of examining the palmitoyl proteomes of multiple cell types. S-palmitoylation of TLR2 is a previously unknown immunoregulatory mechanism that represents an entirely novel avenue for modulation of TLR2 inflammatory activity. Electronic supplementary material The online version of this article (doi:10.1186/s12915-014-0091-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nicholas M Chesarino
- Department of Microbial Infection and Immunity, Center for Microbial Interface Biology, The Ohio State University, Columbus, OH, 43210, USA.
| | - Jocelyn C Hach
- Department of Microbial Infection and Immunity, Center for Microbial Interface Biology, The Ohio State University, Columbus, OH, 43210, USA.
| | - James L Chen
- Biomedical Informatics, Internal Medicine in the Division of Medical Oncology, The Ohio State University, Columbus, OH, 43210, USA.
| | - Balyn W Zaro
- Departments of Chemistry and Molecular and Computational Biology, University of Southern California, Los Angeles, CA, 90089, USA.
| | - Murugesan Vs Rajaram
- Department of Microbial Infection and Immunity, Center for Microbial Interface Biology, The Ohio State University, Columbus, OH, 43210, USA.
| | - Joanne Turner
- Department of Microbial Infection and Immunity, Center for Microbial Interface Biology, The Ohio State University, Columbus, OH, 43210, USA.
| | - Larry S Schlesinger
- Department of Microbial Infection and Immunity, Center for Microbial Interface Biology, The Ohio State University, Columbus, OH, 43210, USA.
| | - Matthew R Pratt
- Departments of Chemistry and Molecular and Computational Biology, University of Southern California, Los Angeles, CA, 90089, USA.
| | - Howard C Hang
- Laboratory of Chemical Biology and Microbial Pathogenesis, Rockefeller University, New York, NY, 10065, USA.
| | - Jacob S Yount
- Department of Microbial Infection and Immunity, Center for Microbial Interface Biology, The Ohio State University, Columbus, OH, 43210, USA.
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Werner JL, Steele C. Innate receptors and cellular defense against pulmonary infections. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2014; 193:3842-50. [PMID: 25281754 PMCID: PMC4185409 DOI: 10.4049/jimmunol.1400978] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In the United States, lung infections consistently rank in the top 10 leading causes of death, accounting for >50,000 deaths annually. Moreover, >140,000 deaths occur annually as a result of chronic lung diseases, some of which may be complicated by an infectious process. The lung is constantly exposed to the environment and is susceptible to infectious complications caused by bacterial, viral, fungal, and parasitic pathogens. Indeed, we are continually faced with the threat of morbidity and mortality associated with annual influenza virus infections, new respiratory viruses (e.g., SARS-CoV), and lung infections caused by antibiotic-resistant "ESKAPE pathogens" (three of which target the lung). This review highlights innate immune receptors and cell types that function to protect against infectious challenges to the respiratory system yet also may be associated with exacerbations in chronic lung diseases.
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Affiliation(s)
- Jessica L Werner
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109; and
| | - Chad Steele
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
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Sendai virus pathogenesis in mice is prevented by Ifit2 and exacerbated by interferon. J Virol 2014; 88:13593-601. [PMID: 25231314 DOI: 10.1128/jvi.02201-14] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
UNLABELLED The type I/III interferon (IFN) system has major roles in regulating viral pathogenesis, usually ameliorating pathogenesis by impairing virus replication through the antiviral actions of one or more IFN-induced proteins. Ifit2 is one such protein which can be induced by IFN or virus infection, and it is responsible for protecting mice from neuropathogenesis caused by vesicular stomatitis virus. Here, we show that Ifit2 also protects mice from pathogenesis caused by the respirovirus Sendai virus (SeV). Mice lacking Ifit2 (Ifit2(-/-)) suffered severe weight loss and succumbed to intranasal infection with SeV strain 52 at a dose that killed only a few wild-type mice. Viral RNA was detectable only in lungs, and SeV titers were higher in Ifit2(-/-) mice than in wild-type mice. Similar infiltration of immune cells was found in the lungs of both mouse lines, corresponding to similar levels of many induced cytokines and chemokines. In contrast, IFN-β and IFN-λ3 expression were considerably higher in the lungs of Ifit2(-/-) mice. Surprisingly, type I IFN receptor knockout (IFNAR(-/-)) mice were less susceptible to SeV than Ifit2(-/-) mice, although their pulmonary virus titers were similarly high. To test the intriguing possibility that type I IFN action enhances pathogenesis in the context of elevated SeV replication in lungs, we generated Ifit2/IFNAR(-/-) double knockout mice. These mice were less susceptible to SeV than Ifit2(-/-) mice, although viral titers in their lungs were even higher. Our results indicate that high SeV replication in the lungs of infected Ifit2(-/-) mice cooperates with elevated IFN-β induction to cause disease. IMPORTANCE The IFN system is an innate defense against virus infections. It is triggered quickly in infected cells, which then secrete IFN. Via their cell surface receptors on surrounding cells, they induce transcription of numerous IFN-stimulated genes (ISG), which in turn protect these cells by inhibiting virus life cycles. Hence, IFNs are commonly considered beneficial during virus infections. Here, we report two key findings. First, lack of a single ISG in mice, Ifit2, resulted in high mortality after SeV infection of the respiratory tract, following higher virus loads and higher IFN production in Ifit2(-/-) lungs. Second, mortality of Ifit2(-/-) mice was reduced when mice also lacked the type I IFN receptor, while SeV loads in lungs still were high. This indicates that type I IFN exacerbates pathogenesis in the SeV model, and that limitation of both viral replication and IFN production is needed for effective prevention of disease.
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Abstract
Viruses efficiently block the host antiviral response in order to replicate and spread before host intervention. The mechanism initiating antiviral immunity during stealth viral replication is unknown, but recent data demonstrate that defective viral genomes generated at peak virus replication are critical for this process in vivo. This article summarizes the supporting evidence and highlights gaps in our understanding of the mechanisms and impact of immunostimulatory defective viral genomes generated during natural infections.
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48
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MDA5 and LGP2: accomplices and antagonists of antiviral signal transduction. J Virol 2014; 88:8194-200. [PMID: 24850739 DOI: 10.1128/jvi.00640-14] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Mammalian cells have the ability to recognize virus infection and mount a powerful antiviral transcriptional response that provides an initial barrier to replication and impacts both innate and adaptive immune responses. Retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) proteins mediate intracellular virus recognition and are activated by viral RNA ligands to induce antiviral signal transduction. While the mechanisms of RIG-I regulation are already well understood, less is known about the more enigmatic melanoma differentiation-associated 5 (MDA5) and laboratory of genetics and physiology 2 (LGP2). Emerging evidence suggests that these two RLRs are intimately associated as both accomplices and antagonists of antiviral signal transduction.
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Paramyxovirus V protein interaction with the antiviral sensor LGP2 disrupts MDA5 signaling enhancement but is not relevant to LGP2-mediated RLR signaling inhibition. J Virol 2014; 88:8180-8. [PMID: 24829334 DOI: 10.1128/jvi.00737-14] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The interferon antiviral system is a primary barrier to virus replication triggered upon recognition of nonself RNAs by the cytoplasmic sensors encoded by retinoic acid-inducible gene I (RIG-I), melanoma differentiation-associated gene 5 (MDA5), and laboratory of genetics and physiology gene 2 (LGP2). Paramyxovirus V proteins are interferon antagonists that can selectively interact with MDA5 and LGP2 through contact with a discrete helicase domain region. Interaction with MDA5, an activator of antiviral signaling, disrupts interferon gene expression and antiviral responses. LGP2 has more diverse reported roles as both a coactivator of MDA5 and a negative regulator of both RIG-I and MDA5. This functional dichotomy, along with the concurrent interference with both cellular targets, has made it difficult to assess the unique consequences of V protein interaction with LGP2. To directly evaluate the impact of LGP2 interference, MDA5 and LGP2 variants unable to be recognized by measles virus and parainfluenza virus 5 (PIV5) V proteins were tested in signaling assays. Results indicate that interaction with LGP2 specifically prevents coactivation of MDA5 signaling and that LGP2's negative regulatory capacity was not affected. V proteins only partially antagonize RIG-I at high concentrations, and their expression had no additive effects on LGP2-mediated negative regulation. However, conversion of RIG-I to a direct V protein target was accomplished by only two amino acid substitutions that allowed both V protein interaction and efficient interference. These results clarify the unique consequences of MDA5 and LGP2 interference by paramyxovirus V proteins and help resolve the distinct roles of LGP2 in both activation and inhibition of antiviral signal transduction. Importance: Paramyxovirus V proteins interact with two innate immune receptors, MDA5 and LGP2, but not RIG-I. V proteins prevent MDA5 from signaling to the beta interferon promoter, but the consequences of LGP2 targeting are poorly understood. As the V protein targets MDA5 and LGP2 simultaneously, and LGP2 is both a positive and negative regulator of both MDA5 and RIG-I, it has been difficult to evaluate the specific advantages conferred by LGP2 targeting. Experiments with V-insensitive proteins revealed that the primary outcome of LGP2 interference is suppression of its ability to synergize with MDA5. LGP2's negative regulation of MDA5 and RIG-I remains intact irrespective of V protein interaction. Complementary experiments demonstrate that RIG-I can be converted to V protein sensitivity by two amino acid substitutions. These findings clarify the functions of LGP2 as a positive regulator of MDA5 signaling, demonstrate the basis for V-mediated LGP2 targeting, and broaden our understanding of paramyxovirus-host interactions.
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Kim WK, Jain D, Sánchez MD, Koziol-White CJ, Matthews K, Ge MQ, Haczku A, Panettieri RA, Frieman MB, López CB. Deficiency of melanoma differentiation-associated protein 5 results in exacerbated chronic postviral lung inflammation. Am J Respir Crit Care Med 2014; 189:437-48. [PMID: 24417465 DOI: 10.1164/rccm.201307-1338oc] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
RATIONALE Respiratory viral infections can result in the establishment of chronic lung diseases. Understanding the early innate immune mechanisms that participate in the development of chronic postviral lung disease may reveal new targets for therapeutic intervention. The intracellular viral sensor protein melanoma differentiation-associated protein 5 (MDA5) sustains the acute immune response to Sendai virus, a mouse pathogen that causes chronic lung inflammation, but its role in the development of postviral chronic lung disease is unknown. OBJECTIVES To establish the role of MDA5 in the development of chronic lung disease. METHODS MDA5-deficient or control mice were infected with Sendai virus. The acute inflammatory response was evaluated by profiling chemokine and cytokine expression and by characterizing the composition of the cellular infiltrate. The impact of MDA5 on chronic lung pathology and function was evaluated through histological studies, degree of oxygen saturation, and responsiveness to carbachol. MEASUREMENTS AND MAIN RESULTS MDA5 deficiency resulted in normal virus replication and in a distinct profile of chemokines and cytokines that associated with acute lung neutropenia and enhanced accumulation of alternatively activated macrophages. Diminished expression of neutrophil-recruiting chemokines was also observed in cells infected with influenza virus, suggesting a key role of MDA5 in driving the early accumulation of neutrophils at the infection site. The biased acute inflammatory response of MDA5-deficient mice led to an enhanced chronic lung inflammation, epithelial cell hyperplasia, airway hyperreactivity, and diminished blood oxygen saturation. CONCLUSIONS MDA5 modulates the development of chronic lung inflammation by regulating the early inflammatory response in the lung.
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Affiliation(s)
- Won-Keun Kim
- 1 Department of Pathobiology, School of Veterinary Medicine, and
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