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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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2
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Musa AO, Faber SR, Forrest K, Smith KP, Sengupta S, López CB. Identification of distinct genotypes in circulating RSV A strains based on variants on the virus replication-associated genes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.22.590570. [PMID: 38712045 PMCID: PMC11071361 DOI: 10.1101/2024.04.22.590570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Respiratory syncytial virus is a common cause of respiratory infection that often leads to hospitalization of infected younger children and older adults. RSV is classified into two strains, A and B, each with several subgroups or genotypes. One issue with the definition of these subgroups is the lack of a unified method of identification or genotyping. We propose that genotyping strategies based on the genes coding for replication-associated proteins could provide critical information on the replication capacity of the distinct subgroup, while clearly distinguishing genotypes. Here, we analyzed the virus replication-associated genes N, P, M2, and L from de novo assembled RSV A sequences obtained from 31 newly sequenced samples from hospitalized patients in Philadelphia and 78 additional publicly available sequences from different geographic locations within the US. In-depth analysis and annotation of the protein variants in L and the other replication-associated proteins N, P, M2-1, and M2-2 identified the polymerase protein L as a robust target for genotyping RSV subgroups. Importantly, our analysis revealed non-synonymous variations in L that were consistently accompanied by conserved changes in its co-factor P or the M2-2 protein, suggesting associations and interactions between specific domains of these proteins. These results highlight L as an alternative to other RSV genotyping targets and demonstrate the value of in-depth analyses and annotations of RSV sequences as it can serve as a foundation for subsequent in vitro and clinical studies on the efficiency of the polymerase and fitness of different virus isolates.
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Affiliation(s)
- Abdulafiz O. Musa
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA
- Center for Womeńs Infectious Diseases Research, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Sydney R. Faber
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA
- Center for Womeńs Infectious Diseases Research, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Kaitlyn Forrest
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Division of Neonatology, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Kenneth P. Smith
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Infectious Disease Diagnostics Laboratory, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Shaon Sengupta
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Division of Neonatology, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Carolina B. López
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA
- Center for Womeńs Infectious Diseases Research, Washington University School of Medicine, Saint Louis, Missouri, USA
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3
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Ranum JN, Ledwith MP, Alnaji FG, Diefenbacher M, Orton R, Sloan E, Güereca M, Feltman E, Smollett K, da Silva Filipe A, Conley M, Russell A, Brooke C, Hutchinson E, Mehle A. Cryptic proteins translated from deletion-containing viral genomes dramatically expand the influenza virus proteome. Nucleic Acids Res 2024; 52:3199-3212. [PMID: 38407436 PMCID: PMC11014358 DOI: 10.1093/nar/gkae133] [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: 12/06/2023] [Revised: 02/06/2024] [Accepted: 02/15/2024] [Indexed: 02/27/2024] Open
Abstract
Productive infections by RNA viruses require faithful replication of the entire genome. Yet many RNA viruses also produce deletion-containing viral genomes (DelVGs), aberrant replication products with large internal deletions. DelVGs interfere with the replication of wild-type virus and their presence in patients is associated with better clinical outcomes. The DelVG RNA itself is hypothesized to confer this interfering activity. DelVGs antagonize replication by out-competing the full-length genome and triggering innate immune responses. Here, we identify an additionally inhibitory mechanism mediated by a new class of viral proteins encoded by DelVGs. We identified hundreds of cryptic viral proteins translated from DelVGs. These DelVG-encoded proteins (DPRs) include canonical viral proteins with large internal deletions, as well as proteins with novel C-termini translated from alternative reading frames. Many DPRs retain functional domains shared with their full-length counterparts, suggesting they may have activity during infection. Mechanistic studies of DPRs derived from the influenza virus protein PB2 showed that they poison replication of wild-type virus by acting as dominant-negative inhibitors of the viral polymerase. These findings reveal that DelVGs have a dual inhibitory mechanism, acting at both the RNA and protein level. They further show that DPRs have the potential to dramatically expand the functional proteomes of diverse RNA viruses.
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Affiliation(s)
- Jordan N Ranum
- Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Mitchell P Ledwith
- Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Fadi G Alnaji
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Meghan Diefenbacher
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Richard Orton
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| | - Elizabeth Sloan
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| | - Melissa Güereca
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Elizabeth M Feltman
- Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Katherine Smollett
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| | | | - Michaela Conley
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| | - Alistair B Russell
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Christopher B Brooke
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Edward Hutchinson
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| | - Andrew Mehle
- Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA
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4
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Ranum JN, Ledwith MP, Alnaji FG, Diefenbacher M, Orton R, Sloan E, Guereca M, Feltman EM, Smollett K, da Silva Filipe A, Conley M, Russell AB, Brooke CB, Hutchinson E, Mehle A. Cryptic proteins translated from deletion-containing viral genomes dramatically expand the influenza virus proteome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.12.570638. [PMID: 38168266 PMCID: PMC10760031 DOI: 10.1101/2023.12.12.570638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Productive infections by RNA viruses require faithful replication of the entire genome. Yet many RNA viruses also produce deletion-containing viral genomes (DelVGs), aberrant replication products with large internal deletions. DelVGs interfere with the replication of wild-type virus and their presence in patients is associated with better clinical outcomes as they. The DelVG RNA itself is hypothesized to confer this interfering activity. DelVGs antagonize replication by out-competing the full-length genome and triggering innate immune responses. Here, we identify an additionally inhibitory mechanism mediated by a new class of viral proteins encoded by DelVGs. We identified hundreds of cryptic viral proteins translated from DelVGs. These DelVG-encoded proteins (DPRs) include canonical viral proteins with large internal deletions, as well as proteins with novel C-termini translated from alternative reading frames. Many DPRs retain functional domains shared with their full-length counterparts, suggesting they may have activity during infection. Mechanistic studies of DPRs derived from the influenza virus protein PB2 showed that they poison replication of wild-type virus by acting as dominant-negative inhibitors of the viral polymerase. These findings reveal that DelVGs have a dual inhibitory mechanism, acting at both the RNA and protein level. They further show that DPRs have the potential to dramatically expand the functional proteomes of diverse RNA viruses.
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Affiliation(s)
- Jordan N Ranum
- Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison WI 53706 USA
| | - Mitchell P Ledwith
- Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison WI 53706 USA
| | - Fadi G Alnaji
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
| | | | - Richard Orton
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| | - Elisabeth Sloan
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| | - Melissa Guereca
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093 USA
| | - Elizabeth M Feltman
- Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison WI 53706 USA
| | - Katherine Smollett
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| | | | - Michaela Conley
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| | - Alistair B Russell
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093 USA
| | - Christopher B Brooke
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, USA
| | - Edward Hutchinson
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| | - Andrew Mehle
- Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison WI 53706 USA
- Lead contact
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5
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Xu Z, Peng Q, Song J, Zhang H, Wei D, Demongeot J, Zeng Q. Bioinformatic analysis of defective viral genomes in SARS-CoV-2 and its impact on population infection characteristics. Front Immunol 2024; 15:1341906. [PMID: 38348041 PMCID: PMC10859446 DOI: 10.3389/fimmu.2024.1341906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 01/12/2024] [Indexed: 02/15/2024] Open
Abstract
DVGs (Defective Viral Genomes) are prevalent in RNA virus infections. In this investigation, we conducted an analysis of high-throughput sequencing data and observed widespread presence of DVGs in SARS-CoV-2. Comparative analysis between SARS-CoV-2 and diverse DNA viruses revealed heightened susceptibility to damage and increased sequencing sample heterogeneity within the SARS-CoV-2 genome. Whole-genome sequencing depth variability analysis exhibited a higher coefficient of variation for SARS-CoV-2, while DVG analysis indicated a significant proportion of recombination sites, signifying notable genome heterogeneity and suggesting that a large proportion of assembled virus particles contain incomplete RNA sequences. Moreover, our investigation explored the sequencing depth and DVG content differences among various strains. Our findings revealed that as the virus evolves, there is a notable increase in the proportion of intact genomes within virus particles, as evidenced by third-generation sequencing data. Specifically, the proportion of intact genome in the Omicron strain surpassed that of the Delta and Alpha strains. This observation effectively elucidates the heightened infectiousness of the Omicron strain compared to the Delta and Alpha strains. We also postulate that this improvement in completeness stems from enhanced virus assembly capacity, as the Omicron strain can promptly facilitate the binding of RNA and capsid protein, thereby reducing the exposure time of vulnerable virus RNA in the host environment and significantly mitigating its degradation. Finally, employing mathematical modeling, we simulated the impact of DVG effects under varying environmental factors on infection characteristics and population evolution. Our findings provide an explanation for the close association between symptom severity and the extent of virus invasion, as well as the substantial disparity in population infection characteristics caused by the same strain under distinct environmental conditions. This study presents a novel approach for future virus research and vaccine development.
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Affiliation(s)
- Zhaobin Xu
- Department of Life Science, Dezhou University, Dezhou, China
| | - Qingzhi Peng
- Department of Life Science, Dezhou University, Dezhou, China
| | - Jian Song
- Department of Life Science, Dezhou University, Dezhou, China
| | - Hongmei Zhang
- Department of Life Science, Dezhou University, Dezhou, China
| | - Dongqing Wei
- State Key Laboratory of Microbial Metabolism, Shanghai-Islamabad-Belgrade Joint Innovation Center on Antibacterial Resistances, Shanghai Jiao Tong University, Shanghai, China
- Joint International Research Laboratory of Metabolic & Developmental Sciences and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- Zhongjing Research and Industrialization Institute of Chinese Medicine, Zhongguancun Scientific Park, Meixi, Nanyang, Henan, China
- Peng Cheng National Laboratory, Shenzhen, Guangdong, China
| | - Jacques Demongeot
- Laboratory AGEIS EA 7407, Team Tools for e-Gnosis Medical, Faculty of Medicine, University Grenoble Alpes (UGA), F-38700 La Tronche, France
| | - Qiangcheng Zeng
- Department of Life Science, Dezhou University, Dezhou, China
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6
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Li X, Ye Z, Plant EP. 5' copyback defective viral genomes are major component in clinical and non-clinical influenza samples. Virus Res 2024; 339:199274. [PMID: 37981214 PMCID: PMC10701078 DOI: 10.1016/j.virusres.2023.199274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/02/2023] [Accepted: 11/16/2023] [Indexed: 11/21/2023]
Abstract
Clinical samples from people with influenza disease have been analyzed to assess the presence and abundance of Defective Viral Genomes (DVGs), but these have not been assessed using the same bioinformatic pipeline. The type of DVG most described for influenza infections (deletion DVGs) differs from the most commonly described DVGs from non-segmented negative stranded viruses (5' copyback). This could be attributed to either differences between viruses or the tools used to detect and characterize DVGs. Here we analyze several NGS datasets from people infected with different types of influenza virus using the same bioinformatic pipeline. We observe that 5' copyback DVGs are prevalent in all human clinical samples but not in the cultured samples. To address this discrepancy between clinical and laboratory cultures, we infected cell culture and ferrets with an H5N8 influenza A virus (FLUAV) and analyzed the DVG composition. The results demonstrate that the DVG population is skewed toward 5' copyback DVGs in the in vivo infections and deletion DVGs in the in vitro infections. This demonstrates that there are differences in vivo genome production and in vitro genome production, and this has implications for how the role of DVGs in clinical disease is studied. We also investigate the role the host cofactor ANP32B has in DVG production.
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Affiliation(s)
- Xing Li
- Laboratory of Pediatric and Respiratory Viral Disease, Office of Vaccine Research and Review, CBER, FDA, Silver Spring, MD, USA
| | - Zhiping Ye
- Laboratory of Pediatric and Respiratory Viral Disease, Office of Vaccine Research and Review, CBER, FDA, Silver Spring, MD, USA
| | - Ewan P Plant
- Laboratory of Pediatric and Respiratory Viral Disease, Office of Vaccine Research and Review, CBER, FDA, Silver Spring, MD, USA.
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7
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Rennick LJ, Duprex WP, Tilston-Lunel NL. Generation of Defective Interfering Particles of Morbilliviruses Using Reverse Genetics. Methods Mol Biol 2024; 2808:57-70. [PMID: 38743362 DOI: 10.1007/978-1-0716-3870-5_5] [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: 05/16/2024]
Abstract
RNA viruses generate defective genomes naturally during virus replication. Defective genomes that interfere with the infection dynamics either through resource competition or by interferon stimulation are known as defective interfering (DI) genomes. DI genomes can be successfully packaged into virus-like-particles referred to as defective interfering particles (DIPs). Such DIPs can sustainably coexist with the full-length virus particles and have been shown to negatively impact virus replication in vitro and in vivo. Here, we describe a method to generate a clonal DI genome population by reverse genetics. This method is applicable to other RNA viruses and will enable assessment of DIPs for their antiviral properties.
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Affiliation(s)
- Linda J Rennick
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - W Paul Duprex
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Natasha L Tilston-Lunel
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, USA
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8
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Achouri E, Felt SA, Hackbart M, Rivera-Espinal NS, López CB. VODKA2: a fast and accurate method to detect non-standard viral genomes from large RNA-seq data sets. RNA (NEW YORK, N.Y.) 2023; 30:16-25. [PMID: 37891004 PMCID: PMC10726161 DOI: 10.1261/rna.079747.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 10/12/2023] [Indexed: 10/29/2023]
Abstract
During viral replication, viruses carrying an RNA genome produce non-standard viral genomes (nsVGs), including copy-back viral genomes (cbVGs) and deletion viral genomes (delVGs), that play a crucial role in regulating viral replication and pathogenesis. Because of their critical roles in determining the outcome of RNA virus infections, the study of nsVGs has flourished in recent years, exposing a need for bioinformatic tools that can accurately identify them within next-generation sequencing data obtained from infected samples. Here, we present our data analysis pipeline, Viral Opensource DVG Key Algorithm 2 (VODKA2), that is optimized to run on a parallel computing environment for fast and accurate detection of nsVGs from large data sets.
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Affiliation(s)
- Emna Achouri
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Sébastien A Felt
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Matthew Hackbart
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Nicole S Rivera-Espinal
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Carolina B López
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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9
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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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10
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Leeks A, Bono LM, Ampolini EA, Souza LS, Höfler T, Mattson CL, Dye AE, Díaz-Muñoz SL. Open questions in the social lives of viruses. J Evol Biol 2023; 36:1551-1567. [PMID: 37975507 DOI: 10.1111/jeb.14203] [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: 10/03/2022] [Revised: 06/12/2023] [Accepted: 06/21/2023] [Indexed: 11/19/2023]
Abstract
Social interactions among viruses occur whenever multiple viral genomes infect the same cells, hosts, or populations of hosts. Viral social interactions range from cooperation to conflict, occur throughout the viral world, and affect every stage of the viral lifecycle. The ubiquity of these social interactions means that they can determine the population dynamics, evolutionary trajectory, and clinical progression of viral infections. At the same time, social interactions in viruses raise new questions for evolutionary theory, providing opportunities to test and extend existing frameworks within social evolution. Many opportunities exist at this interface: Insights into the evolution of viral social interactions have immediate implications for our understanding of the fundamental biology and clinical manifestation of viral diseases. However, these opportunities are currently limited because evolutionary biologists only rarely study social evolution in viruses. Here, we bridge this gap by (1) summarizing the ways in which viruses can interact socially, including consequences for social evolution and evolvability; (2) outlining some open questions raised by viruses that could challenge concepts within social evolution theory; and (3) providing some illustrative examples, data sources, and conceptual questions, for studying the natural history of social viruses.
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Affiliation(s)
- Asher Leeks
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA
- Quantitative Biology Institute, Yale University, New Haven, Connecticut, USA
| | - Lisa M Bono
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas, USA
| | - Elizabeth A Ampolini
- Department of Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Lucas S Souza
- Department of Ecology & Evolutionary Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Thomas Höfler
- Institute of Virology, Freie Universität Berlin, Berlin, Germany
| | - Courtney L Mattson
- Department of Microbiology and Molecular Genetics, University of California Davis, Davis, California, USA
| | - Anna E Dye
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, USA
| | - Samuel L Díaz-Muñoz
- Department of Microbiology and Molecular Genetics, University of California Davis, Davis, California, USA
- Genome Center, University of California Davis, Davis, California, USA
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11
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Pelz L, Piagnani E, Marsall P, Wynserski N, Hein MD, Marichal-Gallardo P, Kupke SY, Reichl U. Broad-Spectrum Antiviral Activity of Influenza A Defective Interfering Particles against Respiratory Syncytial, Yellow Fever, and Zika Virus Replication In Vitro. Viruses 2023; 15:1872. [PMID: 37766278 PMCID: PMC10537524 DOI: 10.3390/v15091872] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 08/25/2023] [Accepted: 09/01/2023] [Indexed: 09/29/2023] Open
Abstract
New broadly acting and readily available antiviral agents are needed to combat existing and emerging viruses. Defective interfering particles (DIPs) of influenza A virus (IAV) are regarded as promising options for the prevention and treatment of IAV infections. Interestingly, IAV DIPs also inhibit unrelated viral infections by stimulating antiviral innate immunity. Here, we tested the ability of IAV DIPs to suppress respiratory syncytial, yellow fever and Zika virus infections in vitro. In human lung (A549) cells, IAV DIP co-infection inhibited the replication and spread of all three viruses. In contrast, we observed no antiviral activity in Vero cells, which are deficient in the production of interferon (IFN), demonstrating its importance for the antiviral effect. Further, in A549 cells, we observed an enhanced type-I and type-III IFN response upon co-infection that appears to explain the antiviral potential of IAV DIPs. Finally, a lack of antiviral activity in the presence of the Janus kinase 1/2 (JAK1/2) inhibitor ruxolitinib was detected. This revealed a dependency of the antiviral activity on the JAK/signal transducers and activators of transcription (STAT) signaling pathway. Overall, this study supports the notion that IAV DIPs may be used as broad-spectrum antivirals to treat infections with a variety of IFN-sensitive viruses, particularly respiratory viruses.
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Affiliation(s)
- Lars Pelz
- Bioprocess Engineering, Max Planck Institute for Dynamics of Complex Technical Systems, 39106 Magdeburg, Germany
| | - Elena Piagnani
- Bioprocess Engineering, Max Planck Institute for Dynamics of Complex Technical Systems, 39106 Magdeburg, Germany
| | - Patrick Marsall
- Bioprocess Engineering, Max Planck Institute for Dynamics of Complex Technical Systems, 39106 Magdeburg, Germany
| | - Nancy Wynserski
- Bioprocess Engineering, Max Planck Institute for Dynamics of Complex Technical Systems, 39106 Magdeburg, Germany
| | - Marc Dominique Hein
- Bioprocess Engineering, Otto von Guericke University Magdeburg, 39106 Magdeburg, Germany
| | - Pavel Marichal-Gallardo
- Bioprocess Engineering, Max Planck Institute for Dynamics of Complex Technical Systems, 39106 Magdeburg, Germany
| | - Sascha Young Kupke
- Bioprocess Engineering, Max Planck Institute for Dynamics of Complex Technical Systems, 39106 Magdeburg, Germany
| | - Udo Reichl
- Bioprocess Engineering, Max Planck Institute for Dynamics of Complex Technical Systems, 39106 Magdeburg, Germany
- Bioprocess Engineering, Otto von Guericke University Magdeburg, 39106 Magdeburg, Germany
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12
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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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13
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Achouri E, Felt SA, Hackbart M, Rivera-Espinal NS, López CB. VODKA2: A fast and accurate method to detect non-standard viral genomes from large RNA-seq datasets. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.25.537842. [PMID: 37163001 PMCID: PMC10168208 DOI: 10.1101/2023.04.25.537842] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
During viral replication, viruses carrying an RNA genome produce non-standard viral genomes (nsVGs), including copy-back viral genomes (cbVGs) and deletion viral genomes (delVGs), that play a crucial role in regulating viral replication and pathogenesis. Because of their critical roles in determining the outcome of RNA virus infections, the study of nsVGs has flourished in recent years exposing a need for bioinformatic tools that can accurately identify them within Next-Generation Sequencing data obtained from infected samples. Here, we present our data analysis pipeline, Viral Opensource DVG Key Algorithm2 (VODKA2), that is optimized to run on a High Performance Computing (HPC) environment for fast and accurate detection of nsVGs from large data sets.
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Affiliation(s)
- Emna Achouri
- Department of Molecular Microbiology and Center for Women Infectious Disease Research, Washington University School of Medicine, St Louis, MO, USA
| | - Sébastien A. Felt
- Department of Molecular Microbiology and Center for Women Infectious Disease Research, Washington University School of Medicine, St Louis, MO, USA
| | - Matthew Hackbart
- Department of Molecular Microbiology and Center for Women Infectious Disease Research, Washington University School of Medicine, St Louis, MO, USA
| | - Nicole S. Rivera-Espinal
- Department of Molecular Microbiology and Center for Women Infectious Disease Research, Washington University School of Medicine, St Louis, MO, USA
| | - Carolina B. López
- Department of Molecular Microbiology and Center for Women Infectious Disease Research, Washington University School of Medicine, St Louis, MO, USA
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14
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Zhou T, Gilliam NJ, Li S, Spandau S, Osborn RM, Connor S, Anderson CS, Mariani TJ, Thakar J, Dewhurst S, Mathews DH, Huang L, Sun Y. Generation and Functional Analysis of Defective Viral Genomes during SARS-CoV-2 Infection. mBio 2023; 14:e0025023. [PMID: 37074178 PMCID: PMC10294654 DOI: 10.1128/mbio.00250-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 03/28/2023] [Indexed: 04/20/2023] Open
Abstract
Defective viral genomes (DVGs) have been identified in many RNA viruses as a major factor influencing antiviral immune response and viral pathogenesis. However, the generation and function of DVGs in SARS-CoV-2 infection are less known. In this study, we elucidated DVG generation in SARS-CoV-2 and its relationship with host antiviral immune response. We observed DVGs ubiquitously from transcriptome sequencing (RNA-seq) data sets of in vitro infections and autopsy lung tissues of COVID-19 patients. Four genomic hot spots were identified for DVG recombination, and RNA secondary structures were suggested to mediate DVG formation. Functionally, bulk and single-cell RNA-seq analysis indicated the interferon (IFN) stimulation of SARS-CoV-2 DVGs. We further applied our criteria to the next-generation sequencing (NGS) data set from a published cohort study and observed a significantly higher amount and frequency of DVG in symptomatic patients than those in asymptomatic patients. Finally, we observed exceptionally diverse DVG populations in one immunosuppressive patient up to 140 days after the first positive test of COVID-19, suggesting for the first time an association between DVGs and persistent viral infections in SARS-CoV-2. Together, our findings strongly suggest a critical role of DVGs in modulating host IFN responses and symptom development, calling for further inquiry into the mechanisms of DVG generation and into how DVGs modulate host responses and infection outcome during SARS-CoV-2 infection. IMPORTANCE Defective viral genomes (DVGs) are generated ubiquitously in many RNA viruses, including SARS-CoV-2. Their interference activity to full-length viruses and IFN stimulation provide the potential for them to be used in novel antiviral therapies and vaccine development. SARS-CoV-2 DVGs are generated through the recombination of two discontinuous genomic fragments by viral polymerase complex, and this recombination is also one of the major mechanisms for the emergence of new coronaviruses. Focusing on the generation and function of SARS-CoV-2 DVGs, these studies identify new hot spots for nonhomologous recombination and strongly suggest that the secondary structures within viral genomes mediate the recombination. Furthermore, these studies provide the first evidence for IFN stimulation activity of de novo DVGs during natural SARS-CoV-2 infection. These findings set up the foundation for further mechanism studies of SARS-CoV-2 recombination and provide evidence to harness the immunostimulatory potential of DVGs in the development of a vaccine and antivirals for SARS-CoV-2.
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Affiliation(s)
- Terry Zhou
- Department of Immunology and Microbiology, University of Rochester Medical Center, Rochester, New York, USA
| | - Nora J. Gilliam
- Department of Immunology and Microbiology, University of Rochester Medical Center, Rochester, New York, USA
- Medical Scientist Training Program, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
- Translational Biomedical Sciences PhD Program, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
| | - Sizhen Li
- School of Electrical Engineering & Computer Science, Oregon State University, Corvallis, Oregon, USA
| | - Simone Spandau
- Department of Immunology and Microbiology, University of Rochester Medical Center, Rochester, New York, USA
| | - Raven M. Osborn
- Department of Immunology and Microbiology, University of Rochester Medical Center, Rochester, New York, USA
- Translational Biomedical Sciences PhD Program, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
| | - Sarah Connor
- Department of Pediatrics and Center for Children’s Health Research, University of Rochester, Rochester, New York, USA
| | - Christopher S. Anderson
- Department of Pediatrics and Center for Children’s Health Research, University of Rochester, Rochester, New York, USA
| | - Thomas J. Mariani
- Department of Pediatrics and Center for Children’s Health Research, University of Rochester, Rochester, New York, USA
| | - Juilee Thakar
- Department of Immunology and Microbiology, University of Rochester Medical Center, Rochester, New York, USA
- Department of Biostatistics and Computational Biology, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
- Department of Biomedical Genetics, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
| | - Stephen Dewhurst
- Department of Immunology and Microbiology, University of Rochester Medical Center, Rochester, New York, USA
| | - David H. Mathews
- Department of Biochemistry & Biophysics and Center for RNA Biology, University of Rochester Medical Center, Rochester, New York, USA
| | - Liang Huang
- School of Electrical Engineering & Computer Science, Oregon State University, Corvallis, Oregon, USA
| | - Yan Sun
- Department of Immunology and Microbiology, University of Rochester Medical Center, Rochester, New York, USA
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15
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Noffel Z, Dobrovolny HM. Quantifying the effect of defective viral genomes in respiratory syncytial virus infections. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2023; 20:12666-12681. [PMID: 37501460 DOI: 10.3934/mbe.2023564] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Defective viral genomes (DVGs) are viral genomes that contain only a partial viral RNA and so cannot replicate within cells on their own. If a cell containing DVGs is subsequently infected with a complete viral genome, the DVG can then use the missing proteins expressed by the full genome in order to replicate itself. Since the cell is producing defective genomes, it has less resources to produce fully functional virions and thus release of complete virions is often suppressed. Here, we use data from challenge studies of respiratory syncytial virus (RSV) in healthy adults to quantify the effect of DVGs. We use a mathematical model to fit the data, finding that late onset of DVGs and prolonged DVG detection are associated with lower infection rates and higher clearance rates. This result could have implications for the use of DVGs as a therapeutic.
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Affiliation(s)
- Zakarya Noffel
- Department of Computer Science, University of Texas at Austin, Austin, TX, US
- Department of Physics & Astronomy, Texas Christian University, Fort Worth, TX, US
| | - Hana M Dobrovolny
- Department of Physics & Astronomy, Texas Christian University, Fort Worth, TX, US
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16
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Cable J, Sun J, Cheon IS, Vaughan AE, Castro IA, Stein SR, López CB, Gostic KM, Openshaw PJM, Ellebedy AH, Wack A, Hutchinson E, Thomas MM, Langlois RA, Lingwood D, Baker SF, Folkins M, Foxman EF, Ward AB, Schwemmle M, Russell AB, Chiu C, Ganti K, Subbarao K, Sheahan TP, Penaloza-MacMaster P, Eddens T. Respiratory viruses: New frontiers-a Keystone Symposia report. Ann N Y Acad Sci 2023; 1522:60-73. [PMID: 36722473 PMCID: PMC10580159 DOI: 10.1111/nyas.14958] [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: 02/02/2023]
Abstract
Respiratory viruses are a common cause of morbidity and mortality around the world. Viruses like influenza, RSV, and most recently SARS-CoV-2 can rapidly spread through a population, causing acute infection and, in vulnerable populations, severe or chronic disease. Developing effective treatment and prevention strategies often becomes a race against ever-evolving viruses that develop resistance, leaving therapy efficacy either short-lived or relevant for specific viral strains. On June 29 to July 2, 2022, researchers met for the Keystone symposium "Respiratory Viruses: New Frontiers." Researchers presented new insights into viral biology and virus-host interactions to understand the mechanisms of disease and identify novel treatment and prevention approaches that are effective, durable, and broad.
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Affiliation(s)
| | - Jie Sun
- Division of Pulmonary and Critical Medicine, Department of Medicine; Department of Immunology; and Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
- Carter Immunology Center and Division of Infectious Disease and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia, USA
| | - In Su Cheon
- Division of Pulmonary and Critical Medicine, Department of Medicine; Department of Immunology; and Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
- Carter Immunology Center and Division of Infectious Disease and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia, USA
| | - Andrew E Vaughan
- University of Pennsylvania School of Veterinary Medicine, Biomedical Sciences, Philadelphia, Pennsylvania, USA
| | - Italo A Castro
- Virology Research Center, Ribeirao Preto Medical School, University of São Paulo - USP, São Paulo, Brazil
| | - Sydney R Stein
- Emerging Pathogens Section, Critical Care Medicine Department, Clinical Center and Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Carolina B López
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Molecular Microbiology and Center for Women Infectious Disease Research, Washington University School of Medicine, St Louis, Missouri, USA
| | - Katelyn M Gostic
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois, USA
| | | | - Ali H Ellebedy
- Department of Pathology and Immunology; The Andrew M. and Jane M. Bursky Center for Human Immunology & Immunotherapy Programs; and Center for Vaccines and Immunity to Microbial Pathogens, Washington University School of Medicine, St Louis, Missouri, USA
| | - Andreas Wack
- Immunoregulation Laboratory, The Francis Crick Institute, London, UK
| | | | | | - Ryan A Langlois
- Center for Immunology and Department of Microbiology and Immunology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Daniel Lingwood
- The Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology, and Harvard University, Cambridge, Massachusetts, USA
| | - Steven F Baker
- Lovelace Biomedical Research Institute, Albuquerque, New Mexico, USA
| | - Melanie Folkins
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Ellen F Foxman
- Department of Laboratory Medicine and Department of Immunology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, USA
| | - Martin Schwemmle
- Institute of Virology, Freiburg University Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Alistair B Russell
- Division of Biological Sciences, University of California, San Diego, La Jolla, California, USA
| | - Christopher Chiu
- Department of Infectious Disease, Imperial College London, London, UK
| | - Ketaki Ganti
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Kanta Subbarao
- Department of Microbiology and Immunology, WHO Collaborating Centre for Reference and Research on Influenza at the Peter Doherty Institute for Infection and Immunity, University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Timothy P Sheahan
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Pablo Penaloza-MacMaster
- Department of Microbiology-Immunology, School of Medicine, Northwestern University Feinberg, Chicago, Illinois, USA
| | - Taylor Eddens
- Pediatric Scientist Development Program, University of Pittsburgh Medical Center (UPMC) Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
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17
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Sotcheff S, Zhou Y, Yeung J, Sun Y, Johnson JE, Torbett BE, Routh AL. ViReMa: a virus recombination mapper of next-generation sequencing data characterizes diverse recombinant viral nucleic acids. Gigascience 2023; 12:giad009. [PMID: 36939008 PMCID: PMC10025937 DOI: 10.1093/gigascience/giad009] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 11/30/2022] [Accepted: 02/03/2023] [Indexed: 03/21/2023] Open
Abstract
BACKGROUND Genetic recombination is a tremendous source of intrahost diversity in viruses and is critical for their ability to rapidly adapt to new environments or fitness challenges. While viruses are routinely characterized using high-throughput sequencing techniques, characterizing the genetic products of recombination in next-generation sequencing data remains a challenge. Viral recombination events can be highly diverse and variable in nature, including simple duplications and deletions, or more complex events such as copy/snap-back recombination, intervirus or intersegment recombination, and insertions of host nucleic acids. Due to the variable mechanisms driving virus recombination and the different selection pressures acting on the progeny, recombination junctions rarely adhere to simple canonical sites or sequences. Furthermore, numerous different events may be present simultaneously in a viral population, yielding a complex mutational landscape. FINDINGS We have previously developed an algorithm called ViReMa (Virus Recombination Mapper) that bootstraps the bowtie short-read aligner to capture and annotate a wide range of recombinant species found within virus populations. Here, we have updated ViReMa to provide an "error density" function designed to accurately detect recombination events in the longer reads now routinely generated by the Illumina platforms and provide output reports for multiple types of recombinant species using standardized formats. We demonstrate the utility and flexibility of ViReMa in different settings to report deletion events in simulated data from Flock House virus, copy-back RNA species in Sendai viruses, short duplication events in HIV, and virus-to-host recombination in an archaeal DNA virus.
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Affiliation(s)
- Stephanea Sotcheff
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Yiyang Zhou
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Jason Yeung
- John Sealy School of Medicine, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Yan Sun
- Department of Microbiology and Immunology, The University of Rochester Medical Center, Rochester, NY 14642, USA
| | - John E Johnson
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, CA 92037, USA
| | - Bruce E Torbett
- Department of Pediatrics, School of Medicine, University of Washington, Seattle, WA 98105, USA
- Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA 98105, USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98195, USA
| | - Andrew L Routh
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX 77555, USA
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX 77555, USA
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA
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18
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Donovan-Banfield I, Milligan R, Hall S, Gao T, Murphy E, Li J, Shawli GT, Hiscox J, Zhuang X, McKeating JA, Fearns R, Matthews DA. Direct RNA sequencing of respiratory syncytial virus infected human cells generates a detailed overview of RSV polycistronic mRNA and transcript abundance. PLoS One 2022; 17:e0276697. [PMID: 36355791 PMCID: PMC9648745 DOI: 10.1371/journal.pone.0276697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 10/11/2022] [Indexed: 11/12/2022] Open
Abstract
To characterize species of viral mRNA transcripts generated during respiratory syncytial virus (RSV) infection, human fibroblast-like MRC-5 lung cells were infected with subgroup A RSV for 6, 16 and 24 hours. In addition, we characterised the viral transcriptome in infected Calu-3 lung epithelial cells at 48 hours post infection. Total RNA was harvested and polyadenylated mRNA was enriched and sequenced by direct RNA sequencing using an Oxford nanopore device. This platform yielded over 450,000 direct mRNA transcript reads which were mapped to the viral genome and analysed to determine the relative mRNA levels of viral genes using our in-house ORF-centric pipeline. We examined the frequency of polycistronic readthrough mRNAs were generated and assessed the length of the polyadenylated tails for each group of transcripts. We show a general but non-linear decline in gene transcript abundance across the viral genome, as predicted by the model of RSV gene transcription. However, the decline in transcript abundance is not uniform. The polyadenylate tails generated by the viral polymerase are similar in length to those generated by the host polyadenylation machinery and broadly declined in length for most transcripts as the infection progressed. Finally, we observed that the steady state abundance of transcripts with very short polyadenylate tails less than 20 nucleotides is less for N, SH and G transcripts in both cell lines compared to NS1, NS2, P, M, F and M2 which may reflect differences in mRNA stability and/or translation rates within and between the cell lines.
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Affiliation(s)
- I’ah Donovan-Banfield
- School of Cellular and Molecular Medicine, Faculty of Life Sciences, University of Bristol, Bristol, United Kingdom
- Department of Infection Biology and Microbiome, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Rachel Milligan
- School of Cellular and Molecular Medicine, Faculty of Life Sciences, University of Bristol, Bristol, United Kingdom
| | - Sophie Hall
- School of Cellular and Molecular Medicine, Faculty of Life Sciences, University of Bristol, Bristol, United Kingdom
| | - Tianyi Gao
- School of Cellular and Molecular Medicine, Faculty of Life Sciences, University of Bristol, Bristol, United Kingdom
| | - Eleanor Murphy
- School of Cellular and Molecular Medicine, Faculty of Life Sciences, University of Bristol, Bristol, United Kingdom
| | - Jack Li
- School of Cellular and Molecular Medicine, Faculty of Life Sciences, University of Bristol, Bristol, United Kingdom
| | - Ghada T. Shawli
- Department of Infection Biology and Microbiome, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Julian Hiscox
- Department of Infection Biology and Microbiome, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Xiaodong Zhuang
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Jane A. McKeating
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Chinese Academy of Medical Sciences Oxford Institute, University of Oxford, Oxford, United Kingdom
| | - Rachel Fearns
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University School of Medicine, Boston, Massachusetts, United States of America
- * E-mail: (DAM); (RF)
| | - David A. Matthews
- School of Cellular and Molecular Medicine, Faculty of Life Sciences, University of Bristol, Bristol, United Kingdom
- * E-mail: (DAM); (RF)
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19
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Penn R, Tregoning JS, Flight KE, Baillon L, Frise R, Goldhill DH, Johansson C, Barclay WS. Levels of Influenza A Virus Defective Viral Genomes Determine Pathogenesis in the BALB/c Mouse Model. J Virol 2022; 96:e0117822. [PMID: 36226985 PMCID: PMC9645217 DOI: 10.1128/jvi.01178-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 08/31/2022] [Indexed: 11/20/2022] Open
Abstract
Defective viral genomes (DVGs), which are generated by the viral polymerase in error during RNA replication, can trigger innate immunity and are implicated in altering the clinical outcome of infection. Here, we investigated the impact of DVGs on innate immunity and pathogenicity in a BALB/c mouse model of influenza virus infection. We generated stocks of influenza viruses containing the internal genes of an H5N1 virus that contained different levels of DVGs (indicated by different genome-to-PFU ratios). In lung epithelial cells, the high-DVG stock was immunostimulatory at early time points postinfection. DVGs were amplified during virus replication in myeloid immune cells and triggered proinflammatory cytokine production. In the mouse model, infection with the different virus stocks produced divergent outcomes. The high-DVG stock induced an early type I interferon (IFN) response that limited viral replication in the lungs, resulting in minimal weight loss. In contrast, the virus stock with low levels of DVGs replicated to high titers and amplified DVGs over time, resulting in elevated levels of proinflammatory cytokines accompanied by rapid weight loss and increased morbidity and mortality. Our results suggest that the timing and levels of immunostimulatory DVGs generated during infection contribute to H5N1 pathogenesis. IMPORTANCE Mammalian infections with highly pathogenic avian influenza viruses (HPAIVs) cause severe disease associated with excessive proinflammatory cytokine production. Aberrant replication products, such as defective viral genomes (DVGs), can stimulate the antiviral response, and cytokine induction is associated with their emergence in vivo. We show that stocks of a recombinant virus containing HPAIV internal genes that differ in their amounts of DVGs have vastly diverse outcomes in a mouse model. The high-DVG stock resulted in extremely mild disease due to suppression of viral replication. Conversely, the stock that contained low DVGs but rapidly accumulated DVGs over the course of infection led to severe disease. Therefore, the timing of DVG amplification and proinflammatory cytokine production impact disease outcome, and these findings demonstrate that not all DVG generation reduces viral virulence. This study also emphasizes the crucial requirement to examine the quality of virus preparations regarding DVG content to ensure reproducible research.
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Affiliation(s)
- Rebecca Penn
- Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - John S. Tregoning
- Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Katie E. Flight
- Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Laury Baillon
- Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Rebecca Frise
- Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Daniel H. Goldhill
- Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Cecilia Johansson
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Wendy S. Barclay
- Department of Infectious Disease, Imperial College London, London, United Kingdom
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20
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Respiratory Syncytial Virus Protects Bystander Cells against Influenza A Virus Infection by Triggering Secretion of Type I and Type III Interferons. J Virol 2022; 96:e0134122. [DOI: 10.1128/jvi.01341-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Influenza A virus (IAV) and respiratory syncytial virus (RSV) are common recurrent respiratory infectants that show a relatively high coincidence. We demonstrated that preinfection with RSV partitions the cell population into a subpopulation susceptible to subsequent infection with IAV and an IAV-proof subpopulation.
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21
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Zhou T, Gilliam NJ, Li S, Spaudau S, Osborn RM, Anderson CS, Mariani TJ, Thakar J, Dewhurst S, Mathews DH, Huang L, Sun Y. Generation and functional analysis of defective viral genomes during SARS-CoV-2 infection.. [PMID: 36172120 PMCID: PMC9516852 DOI: 10.1101/2022.09.22.509123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Defective viral genomes (DVGs) have been identified in many RNA viruses as a major factor influencing antiviral immune response and viral pathogenesis. However, the generation and function of DVGs in SARS-CoV-2 infection are less known. In this study, we elucidated DVG generation in SARS-CoV-2 and its relationship with host antiviral immune response. We observed DVGs ubiquitously from RNA-seq datasets of in vitro infections and autopsy lung tissues of COVID-19 patients. Four genomic hotspots were identified for DVG recombination and RNA secondary structures were suggested to mediate DVG formation. Functionally, bulk and single cell RNA-seq analysis indicated the IFN stimulation of SARS-CoV-2 DVGs. We further applied our criteria to the NGS dataset from a published cohort study and observed significantly higher DVG amount and frequency in symptomatic patients than that in asymptomatic patients. Finally, we observed unusually high DVG frequency in one immunosuppressive patient up to 140 days after admitted to hospital due to COVID-19, first-time suggesting an association between DVGs and persistent viral infections in SARS-CoV-2. Together, our findings strongly suggest a critical role of DVGs in modulating host IFN responses and symptom development, calling for further inquiry into the mechanisms of DVG generation and how DVGs modulate host responses and infection outcome during SARS-CoV-2 infection.
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22
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Segredo-Otero E, Sanjuán R. Cooperative Virus-Virus Interactions: An Evolutionary Perspective. BIODESIGN RESEARCH 2022; 2022:9819272. [PMID: 37850129 PMCID: PMC10521650 DOI: 10.34133/2022/9819272] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 05/21/2022] [Indexed: 10/19/2023] Open
Abstract
Despite extensive evidence of virus-virus interactions, not much is known about their biological significance. Importantly, virus-virus interactions could have evolved as a form of cooperation or simply be a by-product of other processes. Here, we review and discuss different types of virus-virus interactions from the point of view of social evolution, which provides a well-established framework for interpreting the fitness costs and benefits of such traits. We also classify interactions according to their mechanisms of action and speculate on their evolutionary implications. As in any other biological system, the evolutionary stability of viral cooperation critically requires cheaters to be excluded from cooperative interactions. We discuss how cheater viruses exploit cooperative traits and how viral populations are able to counteract this maladaptive process.
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Affiliation(s)
- Ernesto Segredo-Otero
- Institute for Integrative Systems Biology (I2SysBio), Consejo Superior de Investigaciones Científicas-Universitat de València, C/ Catedrático Agustín Escardino 9, 46980 Paterna, València, Spain
| | - Rafael Sanjuán
- Institute for Integrative Systems Biology (I2SysBio), Consejo Superior de Investigaciones Científicas-Universitat de València, C/ Catedrático Agustín Escardino 9, 46980 Paterna, València, Spain
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23
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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: 6] [Impact Index Per Article: 3.0] [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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24
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Abstract
DNA viruses often persist in the body of their host, becoming latent and recurring many months or years later. By contrast, most RNA viruses cause acute infections that are cleared from the host as they lack the mechanisms to persist. However, it is becoming clear that viral RNA can persist after clinical recovery and elimination of detectable infectious virus. This persistence can either be asymptomatic or associated with late progressive disease or nonspecific lingering symptoms, such as may be the case following infection with Ebola or Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Why does viral RNA sometimes persist after recovery from an acute infection? Where does the RNA come from? And what are the consequences?
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25
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Olmo-Uceda MJ, Muñoz-Sánchez JC, Lasso-Giraldo W, Arnau V, Díaz-Villanueva W, Elena SF. DVGfinder: A Metasearch Tool for Identifying Defective Viral Genomes in RNA-Seq Data. Viruses 2022; 14:v14051114. [PMID: 35632855 PMCID: PMC9144107 DOI: 10.3390/v14051114] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 05/18/2022] [Accepted: 05/20/2022] [Indexed: 02/05/2023] Open
Abstract
The generation of different types of defective viral genomes (DVG) is an unavoidable consequence of the error-prone replication of RNA viruses. In recent years, a particular class of DVGs, those containing long deletions or genome rearrangements, has gain interest due to their potential therapeutic and biotechnological applications. Identifying such DVGs in high-throughput sequencing (HTS) data has become an interesting computational problem. Several algorithms have been proposed to accomplish this goal, though all incur false positives, a problem of practical interest if such DVGs have to be synthetized and tested in the laboratory. We present a metasearch tool, DVGfinder, that wraps the two most commonly used DVG search algorithms in a single workflow for the identification of the DVGs in HTS data. DVGfinder processes the results of ViReMa-a and DI-tector and uses a gradient boosting classifier machine learning algorithm to reduce the number of false-positive events. The program also generates output files in user-friendly HTML format, which can help users to explore the DVGs identified in the sample. We evaluated the performance of DVGfinder compared to the two search algorithms used separately and found that it slightly improves sensitivities for low-coverage synthetic HTS data and DI-tector precision for high-coverage samples. The metasearch program also showed higher sensitivity on a real sample for which a set of copy-backs were previously validated.
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Affiliation(s)
- Maria J. Olmo-Uceda
- Instituto de Biología Integrativa de Sistemas (ISysBio), CSIC-Universitat de València, 46980 Valencia, Spain; (M.J.O.-U.); (J.C.M.-S.); (W.L.-G.); (V.A.); (W.D.-V.)
| | - Juan C. Muñoz-Sánchez
- Instituto de Biología Integrativa de Sistemas (ISysBio), CSIC-Universitat de València, 46980 Valencia, Spain; (M.J.O.-U.); (J.C.M.-S.); (W.L.-G.); (V.A.); (W.D.-V.)
| | - Wilberth Lasso-Giraldo
- Instituto de Biología Integrativa de Sistemas (ISysBio), CSIC-Universitat de València, 46980 Valencia, Spain; (M.J.O.-U.); (J.C.M.-S.); (W.L.-G.); (V.A.); (W.D.-V.)
| | - Vicente Arnau
- Instituto de Biología Integrativa de Sistemas (ISysBio), CSIC-Universitat de València, 46980 Valencia, Spain; (M.J.O.-U.); (J.C.M.-S.); (W.L.-G.); (V.A.); (W.D.-V.)
| | - Wladimiro Díaz-Villanueva
- Instituto de Biología Integrativa de Sistemas (ISysBio), CSIC-Universitat de València, 46980 Valencia, Spain; (M.J.O.-U.); (J.C.M.-S.); (W.L.-G.); (V.A.); (W.D.-V.)
| | - Santiago F. Elena
- Instituto de Biología Integrativa de Sistemas (ISysBio), CSIC-Universitat de València, 46980 Valencia, Spain; (M.J.O.-U.); (J.C.M.-S.); (W.L.-G.); (V.A.); (W.D.-V.)
- Santa Fe Institute, Santa Fe, NM 87501, USA
- Correspondence: ; Tel.: +34-963-544-779
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26
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Wang H, Cui X, Cai X, An T. Recombination in Positive-Strand RNA Viruses. Front Microbiol 2022; 13:870759. [PMID: 35663855 PMCID: PMC9158499 DOI: 10.3389/fmicb.2022.870759] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 04/21/2022] [Indexed: 12/28/2022] Open
Abstract
RNA recombination is a major driver of genetic shifts tightly linked to the evolution of RNA viruses. Genomic recombination contributes substantially to the emergence of new viral lineages, expansion in host tropism, adaptations to new environments, and virulence and pathogenesis. Here, we review some of the recent progress that has advanced our understanding of recombination in positive-strand RNA viruses, including recombination triggers and the mechanisms behind them. The study of RNA recombination aids in predicting the probability and outcome of viral recombination events, and in the design of viruses with reduced recombination frequency as candidates for the development of live attenuated vaccines. Surveillance of viral recombination should remain a priority in the detection of emergent viral strains, a goal that can only be accomplished by expanding our understanding of how these events are triggered and regulated.
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Affiliation(s)
| | | | | | - Tongqing An
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
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27
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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: 15] [Impact Index Per Article: 7.5] [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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28
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Harnessing defective viruses to fight infections. MED 2022; 3:1-2. [DOI: 10.1016/j.medj.2021.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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29
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Influenza A Virus Defective Viral Genomes Are Inefficiently Packaged into Virions Relative to Wild-Type Genomic RNAs. mBio 2021; 12:e0295921. [PMID: 34809454 PMCID: PMC8609359 DOI: 10.1128/mbio.02959-21] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Deletion-containing viral genomes (DelVGs) are commonly produced during influenza A virus infection and have been implicated in influencing clinical infection outcomes. Despite their ubiquity, the specific molecular mechanisms that govern DelVG formation and their packaging into defective interfering particles (DIPs) remain poorly understood. Here, we utilized next-generation sequencing to analyze DelVGs that form de novo early during infection, prior to packaging. Analysis of these early DelVGs revealed that deletion formation occurs in clearly defined hot spots and is significantly associated with both direct sequence repeats and enrichment of adenosine and uridine bases. By comparing intracellular DelVGs with those packaged into extracellular virions, we discovered that DelVGs face a significant bottleneck during genome packaging relative to wild-type genomic RNAs. Interestingly, packaged DelVGs exhibited signs of enrichment for larger DelVGs suggesting that size is an important determinant of packaging efficiency. Our data provide the first unbiased, high-resolution portrait of the diversity of DelVGs that are generated by the influenza A virus replication machinery and shed light on the mechanisms that underly DelVG formation and packaging. IMPORTANCE Defective interfering particles (DIPs) are commonly produced by RNA viruses and have been implicated in modulating clinical infection outcomes; hence, there is increasing interest in the potential of DIPs as antiviral therapeutics. For influenza viruses, DIPs are formed by the packaging of genomic RNAs harboring internal deletions. Despite decades of study, the mechanisms that drive the formation of these deletion-containing viral genomes (DelVGs) remain elusive. Here, we used a specialized sequencing pipeline to characterize the first wave of DelVGs that form during influenza virus infection. This data set provides an unbiased profile of the deletion-forming preferences of the influenza virus replicase. In addition, by comparing the early intracellular DelVGs to those that get packaged into extracellular virions, we described a significant segment-specific bottleneck that limits DelVG packaging relative to wild-type viral RNAs. Altogether, these findings reveal factors that govern the production of both DelVGs and DIPs during influenza virus infection.
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30
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Mendes M, Russell AB. Library-based analysis reveals segment and length dependent characteristics of defective influenza genomes. PLoS Pathog 2021; 17:e1010125. [PMID: 34882752 PMCID: PMC8691639 DOI: 10.1371/journal.ppat.1010125] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 12/21/2021] [Accepted: 11/17/2021] [Indexed: 12/14/2022] Open
Abstract
Found in a diverse set of viral populations, defective interfering particles are parasitic variants that are unable to replicate on their own yet rise to relatively high frequencies. Their presence is associated with a loss of population fitness, both through the depletion of key cellular resources and the stimulation of innate immunity. For influenza A virus, these particles contain large internal deletions in the genomic segments which encode components of the heterotrimeric polymerase. Using a library-based approach, we comprehensively profile the growth and replication of defective influenza species, demonstrating that they possess an advantage during genome replication, and that exclusion during population expansion reshapes population composition in a manner consistent with their final, observed, distribution in natural populations. We find that an innate immune response is not linked to the size of a deletion; however, replication of defective segments can enhance their immunostimulatory properties. Overall, our results address several key questions in defective influenza A virus biology, and the methods we have developed to answer those questions may be broadly applied to other defective viruses.
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Affiliation(s)
- Marisa Mendes
- Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Alistair B. Russell
- Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
- * E-mail:
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