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Graves D, Akkerman N, Fulham L, Helwer R, Pelka P. Molecular insights into type I interferon suppression and enhanced pathogenicity by species B human adenoviruses B7 and B14. mBio 2024; 15:e0103824. [PMID: 38940561 PMCID: PMC11323573 DOI: 10.1128/mbio.01038-24] [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] [Received: 04/05/2024] [Accepted: 05/22/2024] [Indexed: 06/29/2024] Open
Abstract
Human adenoviruses (HAdVs) are small DNA viruses that generally cause mild disease. Certain strains, particularly those belonging to species B HAdVs, can cause severe pneumonia and have a relatively high mortality rate. Little is known about the molecular aspects of how these highly pathogenic species affect the infected cell and how they suppress innate immunity. The present study provides molecular insights into how species B adenoviruses suppress the interferon signaling pathway. Our study shows that these viruses, unlike HAdV-C2, are resistant to type I interferon. This resistance likely arises due to the highly efficient suppression of interferon-stimulated gene expression. Unlike in HAdV-C2, HAdV-B7 and B14 sequester STAT2 and RNA polymerase II from interferon-stimulated gene promoters in infected cells. This results in suppressed interferon- stimulated gene activation. In addition, we show that RuvBL1 and RuvBL2, cofactors important for RNA polymerase II recruitment to promoters and interferon-stimulated gene activation, are redirected to the cytoplasm forming high molecular weight complexes that, likely, are unable to associate with chromatin. Proteomic analysis also identified key differences in the way these viruses affect the host cell, providing insights into species B-associated high pathogenicity. Curiously, we observed that at the level of protein expression changes to the infected cell, HAdV-C2 and B7 were more similar than those of the same species, B7 and B14. Collectively, our study represents the first such study of innate immune suppression by the highly pathogenic HAdV-B7 and B14, laying an important foundation for future investigations.IMPORTANCEHuman adenoviruses form a large family of double-stranded DNA viruses known for a variety of usually mild diseases. Certain strains of human adenovirus cause severe pneumonia leading to much higher mortality and morbidity than most other strains. The reasons for this enhanced pathogenicity are unknown. Our study provides a molecular investigation of how these highly pathogenic strains might inactivate the interferon signaling pathway, highlighting the lack of sensitivity of these viruses to type I interferon in general while providing a global picture of how viral changes in cellular proteins drive worse disease outcomes.
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Affiliation(s)
- Drayson Graves
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Nikolas Akkerman
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Lauren Fulham
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Rafe Helwer
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Peter Pelka
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada
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Catalán-Tatjer D, Tzimou K, Nielsen LK, Lavado-García J. Unravelling the essential elements for recombinant adeno-associated virus (rAAV) production in animal cell-based platforms. Biotechnol Adv 2024; 73:108370. [PMID: 38692443 DOI: 10.1016/j.biotechadv.2024.108370] [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: 01/16/2024] [Revised: 04/05/2024] [Accepted: 04/27/2024] [Indexed: 05/03/2024]
Abstract
Recombinant adeno-associated viruses (rAAVs) stand at the forefront of gene therapy applications, holding immense significance for their safe and efficient gene delivery capabilities. The constantly increasing and unmet demand for rAAVs underscores the need for a more comprehensive understanding of AAV biology and its impact on rAAV production. In this literature review, we delved into AAV biology and rAAV manufacturing bioprocesses, unravelling the functions and essentiality of proteins involved in rAAV production. We discuss the interconnections between these proteins and how they affect the choice of rAAV production platform. By addressing existing inconsistencies, literature gaps and limitations, this review aims to define a minimal set of genes that are essential for rAAV production, providing the potential to advance rAAV biomanufacturing, with a focus on minimizing the genetic load within rAAV-producing cells.
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Affiliation(s)
- David Catalán-Tatjer
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark
| | - Konstantina Tzimou
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark
| | - Lars K Nielsen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark; Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Australia
| | - Jesús Lavado-García
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark.
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3
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Bachus S, Akkerman N, Fulham L, Graves D, Helwer R, Rempel J, Pelka P. ARGLU1 enhances promoter-proximal pausing of RNA polymerase II and stimulates DNA damage repair. Nucleic Acids Res 2024; 52:5658-5675. [PMID: 38520408 PMCID: PMC11162773 DOI: 10.1093/nar/gkae208] [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: 10/25/2023] [Revised: 03/05/2024] [Accepted: 03/11/2024] [Indexed: 03/25/2024] Open
Abstract
Arginine and glutamate rich 1 (ARGLU1) is a poorly understood cellular protein with functions in RNA splicing and transcription. Computational prediction suggests that ARGLU1 contains intrinsically disordered regions and lacks any known structural or functional domains. We used adenovirus Early protein 1A (E1A) to probe for critical regulators of important cellular pathways and identified ARGLU1 as a significant player in transcription and the DNA damage response pathway. Transcriptional effects induced by ARGLU1 occur via enhancement of promoter-proximal RNA polymerase II pausing, likely by inhibiting the interaction between JMJD6 and BRD4. When overexpressed, ARGLU1 increases the growth rate of cancer cells, while its knockdown leads to growth arrest. Significantly, overexpression of ARGLU1 increased cancer cell resistance to genotoxic drugs and promoted DNA damage repair. These results identify new roles for ARGLU1 in cancer cell survival and the DNA damage repair pathway, with potential clinical implications for chemotherapy resistance.
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Affiliation(s)
- Scott Bachus
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Buller Building Room 427, Winnipeg, MB R3T 2N2, Canada
| | - Nikolas Akkerman
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Buller Building Room 427, Winnipeg, MB R3T 2N2, Canada
| | - Lauren Fulham
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Buller Building Room 427, Winnipeg, MB R3T 2N2, Canada
| | - Drayson Graves
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Buller Building Room 427, Winnipeg, MB R3T 2N2, Canada
| | - Rafe Helwer
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Buller Building Room 427, Winnipeg, MB R3T 2N2, Canada
| | - Jordan Rempel
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Buller Building Room 427, Winnipeg, MB R3T 2N2, Canada
| | - Peter Pelka
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Buller Building Room 427, Winnipeg, MB R3T 2N2, Canada
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, 45 Chancellor's Circle, Buller Building Room 427, Winnipeg, MB R3T 2N2, Canada
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Jetzer T, Studer L, Bieri M, Greber UF, Hemmi S. Engineered Human Adenoviruses of Species B and C Report Early, Intermediate Early, and Late Viral Gene Expression. Hum Gene Ther 2023; 34:1230-1247. [PMID: 37725579 DOI: 10.1089/hum.2023.121] [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: 09/21/2023] Open
Abstract
Adenoviruses (AdVs) are being developed for oncolytic or vaccination therapy against existing and emerging conditions. Well-characterized replication-competent human and human primate AdVs expressing multiple payloads are desirable, but their replication in rodent models is limited. To score the timing of adenoviral gene expression in cell cultures, we developed fully replication-competent transcriptional reporter viruses for HAdV-C5, -B3, and -B35. The picornavirus-derived 2A sequence, which induces cotranslational peptide splitting and reinitiation (skipping), was linked to GFP and the fused sequence was inserted C-terminal of the early gene E1A, the intermediate early gene protein IX and the late fiber gene. The 2A peptide induced ribosomal skipping during translation of the messenger RNA (mRNA) and gave rise to GFP from the corresponding viral promoters, as shown by immunoblotting and flow cytometry analyses of human and rodent cells. In human cells, both species B and C AdV exhibited highest reporter expression for fiber, followed by protein IX and lowest for E1A. Inoculation with either HAdV-C5 or -B3/35 viruses encoding protein IX- or fiber-GFP gave rise to higher GFP levels in hamster than mouse cells. Remarkably, despite rather low 2A ribosomal skipping efficiency of ∼50% for E1A-2A-GFP, protein IX-2A-GFP, and fiber-2A-GFP, unprocessed protein IX-2A-GFP and fiber-2A-GFP fusion proteins were efficiently incorporated into HAdV-B3 virions, respectively. These data indicate that the B3 C-termini of protein IX and fiber can be considered for retargeting engineered oncolytic or vaccination vectors, or for antigen display. The variable expression levels of transgenes from different subviral promoters may be used to improve oncolytic AdV vectors expressing therapeutic genes.
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Affiliation(s)
- Tania Jetzer
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Lukas Studer
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Manuela Bieri
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
- Molecular Life Science Program, Life Science Zurich Graduate School, Zurich, Switzerland
| | - Urs F Greber
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Silvio Hemmi
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
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Didara Z, Reithofer F, Zöttl K, Jürets A, Kiss I, Witte A, Klein R. Inhibition of adenovirus replication by CRISPR-Cas9-mediated targeting of the viral E1A gene. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 32:48-60. [PMID: 36950281 PMCID: PMC10025986 DOI: 10.1016/j.omtn.2023.02.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 02/28/2023] [Indexed: 03/06/2023]
Abstract
DNA-targeting CRISPR-Cas systems are able to cleave dsDNA in mammalian cells. Accordingly, they have been employed to target the genomes of dsDNA viruses, mostly when present in cells in a non-replicative state with low copy numbers. However, the sheer amount of viral DNA produced within a very short time by certain lytically replicating viruses potentially brings the capacities of CRISPR-Cas systems to their limits. The accessibility of viral DNA replication sites, short time of accessibility of the DNA before encapsidation, or its complexation with shielding proteins are further potential hurdles. Adenoviruses are fast-replicating dsDNA viruses for which no approved antiviral therapy currently exists. We evaluated the potency of CRISPR-Cas9 in inhibiting the replication of human adenovirus 5 in vitro by targeting its master regulator E1A with a set of guide RNAs and observed a decrease in infectious virus particles by up to three orders of magnitude. Target DNA cleavage also negatively impacted the amount of viral DNA accumulated during the infection cycle. This outcome was mainly caused by specific deletions, inversions, and duplications occurring between target sites, which abolished most E1A functions in most cases. Additionally, we compared two strategies for multiplex gRNA expression and obtained comparable results.
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Affiliation(s)
- Zrinka Didara
- Department of Life Sciences, University of Applied Sciences Krems, Piaristengasse 1, 3500 Krems, Austria
| | - Florian Reithofer
- Department of Life Sciences, University of Applied Sciences Krems, Piaristengasse 1, 3500 Krems, Austria
| | - Karina Zöttl
- Department of Life Sciences, University of Applied Sciences Krems, Piaristengasse 1, 3500 Krems, Austria
| | - Alexander Jürets
- Department of Life Sciences, University of Applied Sciences Krems, Piaristengasse 1, 3500 Krems, Austria
| | - Izabella Kiss
- Department of Life Sciences, University of Applied Sciences Krems, Piaristengasse 1, 3500 Krems, Austria
| | - Angela Witte
- Department of Microbiology, Immunobiology, and Genetics, Max Perutz Labs, University of Vienna, Dr. Bohr-Gasse 9, 1030 Vienna, Austria
| | - Reinhard Klein
- Department of Life Sciences, University of Applied Sciences Krems, Piaristengasse 1, 3500 Krems, Austria
- Corresponding author: Reinhard Klein, Department of Life Sciences, University of Applied Sciences Krems, Piaristengasse 1, 3500 Krems, Austria.
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Morshneva AV, Gnedina OO, Kindt DN, Igotti MV. Ras Participates in the Regulation of the Stability of Adenoviral Protein E1A via MAP-kinase ERK. Acta Naturae 2022; 14:78-84. [PMID: 35923563 PMCID: PMC9307986 DOI: 10.32607/actanaturae.11675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 03/18/2022] [Indexed: 11/20/2022] Open
Abstract
The E1A adenoviral protein required for the initiation of the viral life cycle is being actively studied as a sensitizing agent in the combination therapy of cancer, and tumors with activated Ras in particular. We investigated the role played by the Ras signaling pathway in the regulation of E1A protein stability and showed that overexpression of activated Ras increases the basal level of E1A, but enhances the degradation of the E1A protein under treatment with histone deacetylase inhibitors (HDIs). It has been found that the MAP kinase ERK is the key factor in E1A stabilization, and ERK inactivation upon HDI treatment reduces the E1A protein level. Our results indicate that the combination treatment of tumors with activated Ras using adenoviral E1A and HDI has limitations attributed to intense HDI-dependent degradation of E1A. Nevertheless, the established contribution of ERK kinase to the regulation of E1A stability can be used to search for new effective drug combinations based on the adenoviral E1A protein.
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Affiliation(s)
- A. V. Morshneva
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064 Russia
| | - O. O. Gnedina
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064 Russia
| | - D. N. Kindt
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064 Russia
| | - M. V. Igotti
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064 Russia
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7
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Host diversification is concurrent with linear motif evolution in a Mastadenovirus hub protein. J Mol Biol 2022; 434:167563. [PMID: 35351519 DOI: 10.1016/j.jmb.2022.167563] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 02/28/2022] [Accepted: 03/22/2022] [Indexed: 12/23/2022]
Abstract
Over one hundred Mastadenovirus types infect seven orders of mammals. Virus-host coevolution may involve cospeciation, duplication, host switch and partial extinction events. We reconstruct Mastadenovirus diversification, finding that while cospeciation is dominant, the other three events are also common in Mastadenovirus evolution. Linear motifs are fast-evolving protein functional elements and key mediators of virus-host interactions, thus likely to partake in adaptive viral evolution. We study the evolution of eleven linear motifs in the Mastadenovirus E1A protein, a hub of virus-host protein-protein interactions, in the context of host diversification. The reconstruction of linear motif gain and loss events shows fast linear motif turnover, corresponding a virus-host protein-protein interaction turnover orders of magnitude faster than in model host proteomes. Evolution of E1A linear motifs is coupled, indicating functional coordination at the protein scale, yet presents motif-specific patterns suggestive of convergent evolution. We report a pervasive association between Mastadenovirus host diversification events and the evolution of E1A linear motifs. Eight of 17 host switches associate with the gain of one linear motif and the loss of four different linear motifs, while five of nine partial extinctions associate with the loss of one linear motif. The specific changes in E1A linear motifs during a host switch or a partial extinction suggest that changes in the host molecular environment lead to modulation of the interactions with the retinoblastoma protein and host transcriptional regulators. Altogether, changes in the linear motif repertoire of a viral hub protein are associated with adaptive evolution events during Mastadenovirus evolution.
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8
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Tessier TM, Dodge MJ, MacNeil KM, Evans AM, Prusinkiewicz MA, Mymryk JS. Almost famous: Human adenoviruses (and what they have taught us about cancer). Tumour Virus Res 2021; 12:200225. [PMID: 34500123 PMCID: PMC8449131 DOI: 10.1016/j.tvr.2021.200225] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/25/2021] [Accepted: 09/03/2021] [Indexed: 12/11/2022] Open
Abstract
Papillomaviruses, polyomaviruses and adenoviruses are collectively categorized as the small DNA tumour viruses. Notably, human adenoviruses were the first human viruses demonstrated to be able to cause cancer, albeit in non-human animal models. Despite their long history, no human adenovirus is a known causative agent of human cancers, unlike a subset of their more famous cousins, including human papillomaviruses and human Merkel cell polyomavirus. Nevertheless, seminal research using human adenoviruses has been highly informative in understanding the basics of cell cycle control, gene expression, apoptosis and cell differentiation. This review highlights the contributions of human adenovirus research in advancing our knowledge of the molecular basis of cancer.
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Affiliation(s)
- Tanner M Tessier
- Department of Microbiology and Immunology, The University of Western Ontario, London, ON, Canada
| | - Mackenzie J Dodge
- Department of Microbiology and Immunology, The University of Western Ontario, London, ON, Canada
| | - Katelyn M MacNeil
- Department of Microbiology and Immunology, The University of Western Ontario, London, ON, Canada
| | - Andris M Evans
- Department of Microbiology and Immunology, The University of Western Ontario, London, ON, Canada
| | - Martin A Prusinkiewicz
- Department of Microbiology and Immunology, The University of Western Ontario, London, ON, Canada
| | - Joe S Mymryk
- Department of Microbiology and Immunology, The University of Western Ontario, London, ON, Canada; Department of Otolaryngology, Head & Neck Surgery, The University of Western Ontario, London, ON, Canada; Department of Oncology, The University of Western Ontario, London, ON, Canada; London Regional Cancer Program, Lawson Health Research Institute, London, ON, Canada.
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9
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Differential Splicing of Human Adenovirus 5 E1A RNA Expressed in cis versus in trans. J Virol 2021; 95:JVI.02081-20. [PMID: 33361423 DOI: 10.1128/jvi.02081-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 12/10/2020] [Indexed: 01/05/2023] Open
Abstract
Human adenovirus (HAdV) is used extensively as a vector for gene delivery for a variety of purposes, including gene therapy and vaccine development. Most adenoviral vectors used for these approaches have a deletion of early region 1 (E1), which is complemented by the cell line. Most commonly, these are 293 cells for HAdV serotype 2 or 5. The 293 cells have the left end of HAdV5 integrated into chromosome 19 and express the E1 genes and protein IX. We observed that viruses with the E1 region deleted often grow less well on 293 cells than E1 wild-type viruses. Therefore, we investigated whether this poor growth is caused by splicing differences between the E1A RNA provided by the cell line (in trans) and the E1A RNA provided by the infecting viral genome (in cis). We observed that E1A RNA that was expressed from the genomes of 293 cells was spliced differently during infection with an E1A-deleted dl312 virus than E1A RNA from the same cells infected with dl309 or wt300. Importantly, 293 cells were not able to fully complement the late E1A transcripts, specifically 11S, 10S, and 9S RNA, which express the E1A217R, E1A171R, and E1A55R isoforms, respectively. We observed that these splicing differences likely arise due to different subnuclear localizations of E1A RNA. E1A RNA expressed from the viral genome was localized to viral replication centers, while E1A RNA expressed from the cell's genome was not. This loss of the late E1A mRNAs and their associated proteins impacts viral growth, gene expression, and protein levels. Complementation of the late E1A mRNAs in 293 cells restored some of the growth defect observed with dl312 and resulted in higher virus growth.IMPORTANCE Human adenovirus has become an important tool for medicine and research, and 293 cells and various similar cell lines are used extensively for virus production in situations where high viral yields are important. Such complementing cell lines are used for the production of viral vectors and vaccines, which often have deletions and replacements in various viral genes. Deletions in essential genes, such as E1, are often complemented by the cell line that is used for virus propagation in trans Here, we show that even complete genetic complementation of a viral gene does not result in full protein complementation, a defect that compromises virus growth. This is particularly important when high viral yields are crucial, as in virus production for vaccine development or gene therapy.
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Dodge MJ, MacNeil KM, Tessier TM, Weinberg JB, Mymryk JS. Emerging antiviral therapeutics for human adenovirus infection: Recent developments and novel strategies. Antiviral Res 2021; 188:105034. [PMID: 33577808 DOI: 10.1016/j.antiviral.2021.105034] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 02/04/2021] [Accepted: 02/05/2021] [Indexed: 12/11/2022]
Abstract
Human adenoviruses (HAdV) are ubiquitous human pathogens that cause a significant burden of respiratory, ocular, and gastrointestinal illnesses. Although HAdV infections are generally self-limiting, pediatric and immunocompromised individuals are at particular risk for developing severe disease. Currently, no approved antiviral therapies specific to HAdV exist. Recent outbreaks underscore the need for effective antiviral agents to treat life-threatening infections. In this review we will focus on recent developments in search of potential therapeutic agents for controlling HAdV infections, with a focus on those targeting post-entry stages of the virus replicative cycle.
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Affiliation(s)
- Mackenzie J Dodge
- Department of Microbiology and Immunology, The University of Western Ontario, London, ON, Canada
| | - Katelyn M MacNeil
- Department of Microbiology and Immunology, The University of Western Ontario, London, ON, Canada
| | - Tanner M Tessier
- Department of Microbiology and Immunology, The University of Western Ontario, London, ON, Canada
| | - Jason B Weinberg
- Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA; Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
| | - Joe S Mymryk
- Department of Microbiology and Immunology, The University of Western Ontario, London, ON, Canada; Department of Otolaryngology, Head & Neck Surgery, The University of Western Ontario, London, ON, Canada; Department of Oncology, The University of Western Ontario, London, ON, Canada; London Regional Cancer Program, Lawson Health Research Institute, London, ON, Canada.
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Differential Effects of Human Adenovirus E1A Protein Isoforms on Aerobic Glycolysis in A549 Human Lung Epithelial Cells. Viruses 2020; 12:v12060610. [PMID: 32503156 PMCID: PMC7354625 DOI: 10.3390/v12060610] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/30/2020] [Accepted: 06/02/2020] [Indexed: 12/14/2022] Open
Abstract
Viruses alter a multitude of host-cell processes to create a more optimal environment for viral replication. This includes altering metabolism to provide adequate substrates and energy required for replication. Typically, viral infections induce a metabolic phenotype resembling the Warburg effect, with an upregulation of glycolysis and a concurrent decrease in cellular respiration. Human adenovirus (HAdV) has been observed to induce the Warburg effect, which can be partially attributed to the adenovirus protein early region 4, open reading frame 1 (E4orf1). E4orf1 regulates a multitude of host-cell processes to benefit viral replication and can influence cellular metabolism through the transcription factor avian myelocytomatosis viral oncogene homolog (MYC). However, E4orf1 does not explain the full extent of Warburg-like HAdV metabolic reprogramming, especially the accompanying decrease in cellular respiration. The HAdV protein early region 1A (E1A) also modulates the function of the infected cell to promote viral replication. E1A can interact with a wide variety of host-cell proteins, some of which have been shown to interact with metabolic enzymes independently of an interaction with E1A. To determine if the HAdV E1A proteins are responsible for reprogramming cell metabolism, we measured the extracellular acidification rate and oxygen consumption rate of A549 human lung epithelial cells with constitutive endogenous expression of either of the two major E1A isoforms. This was followed by the characterization of transcript levels for genes involved in glycolysis and cellular respiration, and related metabolic pathways. Cells expressing the 13S encoded E1A isoform had drastically increased baseline glycolysis and lower maximal cellular respiration than cells expressing the 12S encoded E1A isoform. Cells expressing the 13S encoded E1A isoform exhibited upregulated expression of glycolysis genes and downregulated expression of cellular respiration genes. However, tricarboxylic acid cycle genes were upregulated, resembling anaplerotic metabolism employed by certain cancers. Upregulation of glycolysis and tricarboxylic acid cycle genes was also apparent in IMR-90 human primary lung fibroblast cells infected with a HAdV-5 mutant virus that expressed the 13S, but not the 12S encoded E1A isoform. In conclusion, it appears that the two major isoforms of E1A differentially influence cellular glycolysis and oxidative phosphorylation and this is at least partially due to the altered regulation of mRNA expression for the genes in these pathways.
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12
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Characterization of Adenovirus 5 E1A Exon 1 Deletion Mutants in the Viral Replicative Cycle. Viruses 2020; 12:v12020213. [PMID: 32075072 PMCID: PMC7077205 DOI: 10.3390/v12020213] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 02/10/2020] [Accepted: 02/12/2020] [Indexed: 02/06/2023] Open
Abstract
Human adenovirus infection is driven by Early region 1A (E1A) proteins, which are the first proteins expressed following the delivery of the viral genome to the cellular nucleus. E1A is responsible for reprogramming the infected cell to support virus replication alongside the activation of expression of all viral transcriptional units during the course of the infection. Although E1A has been extensively studied, most of these studies have focused on understanding the conserved region functions outside of a full infection. Here, we investigated the effects of small deletions in E1A exon 1 on the viral replicative cycle. Almost all deletions were found to have a negative impact on viral replication with the exception of one deletion found in the mutant dl1106, which replicated better than the wild-type E1A expressing dl309. In addition to growth, we assessed the virus mutants for genome replication, induction of the cytopathic effect, gene and protein expression, sub-cellular localization of E1A mutant proteins, induction of cellular S-phase, and activation of S-phase specific cellular genes. Importantly, our study found that virus replication is likely limited by host-specific factors, rather than specific viral aspects such as the ability to replicate genomes or express late proteins, after a certain level of these has been expressed. Furthermore, we show that mutants outside of the conserved regions have significant influence on viral fitness. Overall, our study is the first comprehensive evaluation of the dl1100 series of exon 1 E1A deletion mutants in viral fitness and provides important insights into the contribution that E1A makes to viral replication in normal human cells.
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H3K18Ac as a Marker of Cancer Progression and Potential Target of Anti-Cancer Therapy. Cells 2019; 8:cells8050485. [PMID: 31121824 PMCID: PMC6562857 DOI: 10.3390/cells8050485] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/13/2019] [Accepted: 05/16/2019] [Indexed: 02/07/2023] Open
Abstract
Acetylation and deacetylation are posttranslational modifications (PTMs) which affect the regulation of chromatin structure and its remodeling. Acetylation of histone 3 at lysine placed on position 18 (H3K18Ac) plays an important role in driving progression of many types of cancer, including breast, colon, lung, hepatocellular, pancreatic, prostate, and thyroid cancer. The aim of this review is to analyze and discuss the newest findings regarding the role of H3K18Ac and acetylation of other histones in carcinogenesis. We summarize the level of H3K18Ac in different cancer cell lines and analyze its association with patients’ outcomes, including overall survival (OS), progression-free survival (PFS), and disease-free survival (DFS). Finally, we describe future perspectives of cancer therapeutic strategies based on H3K18 modifications.
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Adenovirus 5 E1A Interacts with E4orf3 To Regulate Viral Chromatin Organization. J Virol 2019; 93:JVI.00157-19. [PMID: 30842325 DOI: 10.1128/jvi.00157-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 02/27/2019] [Indexed: 01/05/2023] Open
Abstract
Human adenovirus expresses several early proteins that control various aspects of the viral replication program, including an orchestrated expression of viral genes. Two of the earliest viral transcriptional units activated after viral genome entry into the host cell nucleus are the E1 and E4 units, which each express a variety of proteins. Chief among these are the E1A proteins that function to reprogram the host cell and activate transcription of all other viral genes. The E4 gene encodes multiple proteins, including E4orf3, which functions to disrupt cellular antiviral defenses, including the DNA damage response pathway and activation of antiviral genes. Here we report that E1A directly interacts with E4orf3 via the conserved N terminus of E1A to regulate the expression of viral genes. We show that E4orf3 indiscriminately drives high nucleosomal density of viral genomes, which is restrictive to viral gene expression and which E1A overcomes via a direct interaction with E4orf3. We also show that during infection E1A colocalizes with E4orf3 to nuclear tracks that are associated with heterochromatin formation. The inability of E1A to interact with E4orf3 has a significant negative impact on overall viral replication, the ability of the virus to reprogram the host cell, and the levels of viral gene expression. Together these results show that E1A and E4orf3 work together to fine-tune the viral replication program during the course of infection and highlight a novel mechanism that regulates viral gene expression.IMPORTANCE To successfully replicate, human adenovirus needs to carry out a rapid yet ordered transcriptional program that executes and drives viral replication. Early in infection, the viral E1A proteins are the key activators and regulators of viral transcription. Here we report, for the first time, that E1A works together with E4orf3 to perfect the viral transcriptional program and identify a novel mechanism by which the virus can adjust viral gene expression by modifying its genome's nucleosomal organization via cooperation between E1A and E4orf3.
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15
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Cervera-Carrascon V, Havunen R, Hemminki A. Oncolytic adenoviruses: a game changer approach in the battle between cancer and the immune system. Expert Opin Biol Ther 2019; 19:443-455. [PMID: 30905206 DOI: 10.1080/14712598.2019.1595582] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Oncolytic adenoviruses are among the most studied oncolytic viruses because of their tumor selectivity, safety, and transgene-delivery capability. With a growing number of different immunotherapies against cancer, the extraordinary immunogenicity of the adenovirus has emerged as a differentiating strength. Enabling T-cell related therapies with oncolytic adenoviruses appears a promising approach due to its inherent ability to elicit responses from the adaptive immune compartment. AREAS COVERED These viruses have successfully enhanced both adoptive T-cell therapies and immune-checkpoint therapies. Oncolytic viruses induce several effects at the tumor and on the systemic level that help to circumvent current limitations of T-cells and related therapies, such as T-cell trafficking, tumor immune suppressivity and antigen spreading EXPERT OPINION Taking into account the multitude of possibilities of treating cancer with immunotherapies, learning to optimize the combinations and administration strategies of these drugs, could lead to durable responses in patients with currently incurable cancers.
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Affiliation(s)
- Victor Cervera-Carrascon
- a Cancer Gene Therapy Group, Translational Immunology Research Program, Faculty of Medicine , University of Helsinki , Helsinki , Finland.,b TILT Biotherapeutics Ltd , Helsinki , Finland
| | - Riikka Havunen
- a Cancer Gene Therapy Group, Translational Immunology Research Program, Faculty of Medicine , University of Helsinki , Helsinki , Finland.,b TILT Biotherapeutics Ltd , Helsinki , Finland
| | - Akseli Hemminki
- a Cancer Gene Therapy Group, Translational Immunology Research Program, Faculty of Medicine , University of Helsinki , Helsinki , Finland.,b TILT Biotherapeutics Ltd , Helsinki , Finland.,c Hospital Comprehensive Cancer Center , Helsinki University , Helsinki , Finland
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16
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Crisostomo L, Soriano AM, Mendez M, Graves D, Pelka P. Temporal dynamics of adenovirus 5 gene expression in normal human cells. PLoS One 2019; 14:e0211192. [PMID: 30677073 PMCID: PMC6345434 DOI: 10.1371/journal.pone.0211192] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 01/08/2019] [Indexed: 01/22/2023] Open
Abstract
Adenovirus executes a finely tuned transcriptional program upon infection of a cell. To better understand the temporal dynamics of the viral transcriptional program we performed highly sensitive digital PCR on samples extracted from arrested human lung fibroblasts infected with human adenovirus 5 strain dl309. We show that the first transcript made from viral genomes is the virus associated non-coding RNA, in particular we detected abundant levels of virus associated RNA II four hours after infection. Activation of E1 and E4 occurred nearly simultaneously later in infection, followed by other early genes as well as late genes. Our study determined that genomes begin to replicate between 29 and 30 hours after infection. This study provides a comprehensive view of viral mRNA steady-state kinetics in arrested human cells using digital PCR.
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Affiliation(s)
- Leandro Crisostomo
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | | | - Megan Mendez
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Drayson Graves
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Peter Pelka
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
- * E-mail:
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17
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Boemo MA, Byrne HM. Mathematical modelling of a hypoxia-regulated oncolytic virus delivered by tumour-associated macrophages. J Theor Biol 2018; 461:102-116. [PMID: 30359572 PMCID: PMC6269600 DOI: 10.1016/j.jtbi.2018.10.044] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/02/2018] [Accepted: 10/22/2018] [Indexed: 01/16/2023]
Abstract
A continuum model of macrophages releasing an oncolytic virus within a tumour spheroid. Predictive modelling of this treatment given in combination with radiotherapy. Investigation into how radiotherapy and oncolytic virotherapy should be scheduled.
Tumour hypoxia has long presented a challenge for cancer therapy: Poor vascularisation in hypoxic regions hinders both the delivery of chemotherapeutic agents and the response to radiotherapy, and hypoxic cancer cells that survive treatment can trigger tumour regrowth after treatment has ended. Tumour-associated macrophages are attractive vehicles for drug delivery because they localise in hypoxic areas of the tumour. In this paper, we derive a mathematical model for the infiltration of an in vitro tumour spheroid by macrophages that have been engineered to release an oncolytic adenovirus under hypoxic conditions. We use this model to predict the efficacy of treatment schedules in which radiotherapy and the engineered macrophages are given in combination. Our work suggests that engineered macrophages should be introduced immediately after radiotherapy for maximum treatment efficacy. Our model provides a framework that may guide future experiments to determine how multiple rounds of radiotherapy and macrophage virotherapy should be coordinated to maximise therapeutic responses.
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Affiliation(s)
- Michael A Boemo
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, United Kingdom.
| | - Helen M Byrne
- Mathematical Institute, University of Oxford, Andrew Wiles Building, Woodstock Road, Oxford, OX2 6GG, United Kingdom.
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18
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Moreau P, Cournac A, Palumbo GA, Marbouty M, Mortaza S, Thierry A, Cairo S, Lavigne M, Koszul R, Neuveut C. Tridimensional infiltration of DNA viruses into the host genome shows preferential contact with active chromatin. Nat Commun 2018; 9:4268. [PMID: 30323189 PMCID: PMC6189100 DOI: 10.1038/s41467-018-06739-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 09/19/2018] [Indexed: 01/05/2023] Open
Abstract
Whether non-integrated viral DNAs distribute randomly or target specific positions within the higher-order architecture of mammalian genomes remains largely unknown. Here we use Hi-C and viral DNA capture (CHi-C) in primary human hepatocytes infected by either hepatitis B virus (HBV) or adenovirus type 5 (Ad5) virus to show that they adopt different strategies in their respective positioning at active chromatin. HBV contacts preferentially CpG islands (CGIs) enriched in Cfp1 a factor required for its transcription. These CGIs are often associated with highly expressed genes (HEG) and genes deregulated during infection. Ad5 DNA interacts preferentially with transcription start sites (TSSs) and enhancers of HEG, as well as genes upregulated during infection. These results show that DNA viruses use different strategies to infiltrate genomic 3D networks and target specific regions. This targeting may facilitate the recruitment of transcription factors necessary for their own replication and contribute to the deregulation of cellular gene expression.
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Affiliation(s)
- Pierrick Moreau
- Institut Pasteur, Unité Hepacivirus et Immunité Innée, 75015, Paris, France.,CNRS, UMR 3569, 75015, Paris, France.,Institut Pasteur, Département de Virologie, Paris, France
| | - Axel Cournac
- Institut Pasteur, Département Génomes et Génétique, Groupe Régulation spatiale des génomes, 75015, Paris, France.,CNRS, UMR 3525, 75015, Paris, France
| | - Gianna Aurora Palumbo
- Institut Pasteur, Unité Hepacivirus et Immunité Innée, 75015, Paris, France.,CNRS, UMR 3569, 75015, Paris, France.,Institut Pasteur, Département de Virologie, Paris, France
| | - Martial Marbouty
- Institut Pasteur, Département Génomes et Génétique, Groupe Régulation spatiale des génomes, 75015, Paris, France.,CNRS, UMR 3525, 75015, Paris, France
| | - Shogofa Mortaza
- Institut Pasteur, Département Génomes et Génétique, Groupe Régulation spatiale des génomes, 75015, Paris, France.,CNRS, UMR 3525, 75015, Paris, France
| | - Agnes Thierry
- Institut Pasteur, Département Génomes et Génétique, Groupe Régulation spatiale des génomes, 75015, Paris, France.,CNRS, UMR 3525, 75015, Paris, France
| | - Stefano Cairo
- XenTech, Research and Development Department, 91000, Evry, France
| | - Marc Lavigne
- Institut Pasteur, Département de Virologie, Paris, France.,Institut Cochin-INSERM U1016-CNRS UMR8104, Université Paris Descartes, Paris, France
| | - Romain Koszul
- Institut Pasteur, Département Génomes et Génétique, Groupe Régulation spatiale des génomes, 75015, Paris, France. .,CNRS, UMR 3525, 75015, Paris, France.
| | - Christine Neuveut
- Institut Pasteur, Unité Hepacivirus et Immunité Innée, 75015, Paris, France. .,CNRS, UMR 3569, 75015, Paris, France. .,Institut Pasteur, Département de Virologie, Paris, France.
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19
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Glavina J, Román EA, Espada R, de Prat-Gay G, Chemes LB, Sánchez IE. Interplay between sequence, structure and linear motifs in the adenovirus E1A hub protein. Virology 2018; 525:117-131. [PMID: 30265888 DOI: 10.1016/j.virol.2018.08.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 08/13/2018] [Accepted: 08/14/2018] [Indexed: 01/04/2023]
Abstract
E1A is the main transforming protein in mastadenoviruses. This work uses bioinformatics to extrapolate experimental knowledge from Human adenovirus serotype 5 and 12 E1A proteins to all known serotypes. A conserved domain architecture with a high degree of intrinsic disorder acts as a scaffold for multiple linear motifs with variable occurrence mediating the interaction with over fifty host proteins. While linear motifs contribute strongly to sequence conservation within intrinsically disordered E1A regions, motif repertoires can deviate significantly from those found in prototypical serotypes. Close to one hundred predicted residue-residue contacts suggest the presence of stable structure in the CR3 domain and of specific conformational ensembles involving both short- and long-range intramolecular interactions. Our computational results suggest that E1A sequence conservation and co-evolution reflect the evolutionary pressure to maintain a mainly disordered, yet non-random conformation harboring a high number of binding motifs that mediate viral hijacking of the cell machinery.
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Affiliation(s)
- Juliana Glavina
- Universidad de Buenos Aires. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN). Facultad de Ciencias Exactas y Naturales. Laboratorio de Fisiología de Proteínas. Buenos Aires, Argentina
| | - Ernesto A Román
- Instituto de Química y Físico-Química Biológicas, Universidad de Buenos Aires, Junín 956, 1113AAD, Buenos Aires, Argentina
| | - Rocío Espada
- Universidad de Buenos Aires. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN). Facultad de Ciencias Exactas y Naturales. Laboratorio de Fisiología de Proteínas. Buenos Aires, Argentina
| | - Gonzalo de Prat-Gay
- Protein Structure-Function and Engineering Laboratory, Fundación Instituto Leloir and IIBBA-CONICET, Buenos Aires, Argentina
| | - Lucía B Chemes
- Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Biotecnológicas IIB-INTECH, Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina; Departamento de Fisiología y Biología Molecular y Celular (DFBMC), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
| | - Ignacio E Sánchez
- Universidad de Buenos Aires. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN). Facultad de Ciencias Exactas y Naturales. Laboratorio de Fisiología de Proteínas. Buenos Aires, Argentina.
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20
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Adenovirus 5 E1A-Mediated Suppression of p53 via FUBP1. J Virol 2018; 92:JVI.00439-18. [PMID: 29743362 DOI: 10.1128/jvi.00439-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 05/02/2018] [Indexed: 12/31/2022] Open
Abstract
Far-upstream element (FUSE) binding protein 1 (FUBP1) was originally identified as a regulator of the oncogene c-Myc via binding to the FUSE within the c-Myc promoter and activating the expression of the gene. Recent studies have identified FUBP1 as a regulator of transcription, translation, and splicing via its DNA and RNA binding activities. Here we report the identification of FUBP1 as a novel binding partner of E1A. FUBP1 binds directly to E1A via the N terminus (residues 1 to 82) and conserved region 3 (residues 139 to 204) of adenovirus 5 E1A. The depletion of FUBP1 via short interfering RNAs (siRNA) reduces virus growth and drives the upregulation of the cellular stress response by activating the expression of p53-regulated genes. During infection, FUBP1 is relocalized within the nucleus, and it is recruited to viral promoters together with E1A while at the same time being lost from the FUSE upstream of the c-Myc promoter. The depletion of FUBP1 affects viral and cellular gene expression. Importantly, in FUBP1-depleted cells, p53-responsive genes are upregulated, p53 occupancy on target promoters is enhanced, and histone H3 lysine 9 is hyperacetylated. This is likely due to the loss of the FUBP1-mediated suppression of p53 DNA binding. We also observed that E1A stabilizes the FUBP1-p53 complex, preventing p53 promoter binding. Together, our results identify, for the first time, FUBP1 as a novel E1A binding protein that participates in aspects of viral replication and is involved in the E1A-mediated suppression of p53 function.IMPORTANCE Viral infection triggers innate cellular defense mechanisms that have evolved to block virus replication. To overcome this, viruses have counterevolved mechanisms that ensure that cellular defenses are either disarmed or not activated to guarantee successful replication. One of the key regulators of cellular stress is the tumor suppressor p53 that responds to a variety of cellular stress stimuli and safeguards the integrity of the genome. During infection, many viruses target the p53 pathway in order to deactivate it. Here we report that human adenovirus 5 coopts the cellular protein FUBP1 to prevent the activation of the p53 stress response pathway that would block viral replication. This finding adds to our understanding of p53 deactivation by adenovirus and highlights its importance in infection and innate immunity.
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21
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Abstract
As obligate intracellular parasites, viruses are dependent on their infected hosts for survival. Consequently, viruses are under enormous selective pressure to utilize available cellular components and processes to their own advantage. As most, if not all, cellular activities are regulated at some level via protein interactions, host protein interaction networks are particularly vulnerable to viral exploitation. Indeed, viral proteins frequently target highly connected “hub” proteins to “hack” the cellular network, defining the molecular basis for viral control over the host. This widespread and successful strategy of network intrusion and exploitation has evolved convergently among numerous genetically distinct viruses as a result of the endless evolutionary arms race between pathogens and hosts. Here we examine the means by which a particularly well-connected viral hub protein, human adenovirus E1A, compromises and exploits the vulnerabilities of eukaryotic protein interaction networks. Importantly, these interactions identify critical regulatory hubs in the human proteome and help define the molecular basis of their function.
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22
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The Influence of E1A C-Terminus on Adenovirus Replicative Cycle. Viruses 2017; 9:v9120387. [PMID: 29257057 PMCID: PMC5744161 DOI: 10.3390/v9120387] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 12/15/2017] [Accepted: 12/16/2017] [Indexed: 01/30/2023] Open
Abstract
Adenovirus Early 1A proteins (E1A) are crucial for initiation of the viral life cycle after infection. The E1A gene is encoded at the left end of the viral genome and consists of two exons, the first encoding 185 amino acids in the 289 residues adenovirus 5 E1A, while the second exon encodes 104 residues. The second exon-encoded region of E1A is conserved across all E1A isoforms except for the 55 residues protein, which has a unique C-terminus due to a frame shift following splicing into the second exon. This region of E1A contributes to a variety of processes including the regulation of viral and cellular gene expression, immortalization and transformation. Here we evaluated the contributions that different regions of the second exon of E1A make to the viral life cycle using deletion mutants. The region of E1A encoded by the second exon was found to be important for overall virus growth, induction of viral and cellular gene expression, viral genome replication and deregulation of the cell cycle. Efficient viral replication was found to require exon 2 and the nuclear localization signal, as loss of either resulted in severe growth deficiency. Induction of cellular DNA synthesis was also deficient with any deletion of E1A within the C-terminus even if these deletions were outside of conserved region 4. Overall, our study provides the first comprehensive insight into the contributions of the C-terminus of E1A to the replicative fitness of human adenovirus 5 in arrested lung fibroblasts.
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23
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Simultaneous Single-Cell In Situ Analysis of Human Adenovirus Type 5 DNA and mRNA Expression Patterns in Lytic and Persistent Infection. J Virol 2017; 91:JVI.00166-17. [PMID: 28298601 DOI: 10.1128/jvi.00166-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 03/06/2017] [Indexed: 12/14/2022] Open
Abstract
An efficient adenovirus infection results in high-level accumulation of viral DNA and mRNAs in the infected cell population. However, the average viral DNA and mRNA content in a heterogeneous cell population does not necessarily reflect the same abundance in individual cells. Here, we describe a novel padlock probe-based rolling-circle amplification technique that enables simultaneous detection and analysis of human adenovirus type 5 (HAdV-5) genomic DNA and virus-encoded mRNAs in individual infected cells. We demonstrate that the method is applicable for detection and quantification of HAdV-5 DNA and mRNAs in short-term infections in human epithelial cells and in long-term infections in human B lymphocytes. Single-cell evaluation of these infections revealed high heterogeneity and unique cell subpopulations defined by differential viral DNA content and mRNA expression. Further, our single-cell analysis shows that the specific expression pattern of viral E1A 13S and 12S mRNA splice variants is linked to HAdV-5 DNA content in the individual cells. Furthermore, we show that expression of a mature form of the HAdV-5 histone-like protein VII affects virus genome detection in HAdV-5-infected cells. Collectively, padlock probes combined with rolling-circle amplification should be a welcome addition to the method repertoire for the characterization of the molecular details of the HAdV life cycle in individual infected cells.IMPORTANCE Human adenoviruses (HAdVs) have been extensively used as model systems to study various aspects of eukaryotic gene expression and genome organization. The vast majority of the HAdV studies are based on standard experimental procedures carried out using heterogeneous cell populations, where data averaging often masks biological differences. As every cell is unique, characteristics and efficiency of an HAdV infection can vary from cell to cell. Therefore, the analysis of HAdV gene expression and genome organization would benefit from a method that permits analysis of individual infected cells in the heterogeneous cell population. Here, we show that the padlock probe-based rolling-circle amplification method can be used to study concurrent viral DNA accumulation and mRNA expression patterns in individual HAdV-5-infected cells. Hence, this versatile method can be applied to detect the extent of infection and virus gene expression changes in different HAdV-5 infections.
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24
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Suppression of Type I Interferon Signaling by E1A via RuvBL1/Pontin. J Virol 2017; 91:JVI.02484-16. [PMID: 28122980 DOI: 10.1128/jvi.02484-16] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 01/18/2017] [Indexed: 11/20/2022] Open
Abstract
Suppression of interferon signaling is of paramount importance to a virus. Interferon signaling significantly reduces or halts the ability of a virus to replicate; therefore, viruses have evolved sophisticated mechanisms that suppress activation of the interferon pathway or responsiveness of the infected cell to interferon. Adenovirus has multiple modes of inhibiting the cellular response to interferon. Here, we report that E1A, previously shown to regulate interferon signaling in multiple ways, inhibits interferon-stimulated gene expression by modulating RuvBL1 function. RuvBL1 was previously shown to affect type I interferon signaling. E1A binds to RuvBL1 and is recruited to RuvBL1-regulated promoters in an interferon-dependent manner, preventing their activation. Depletion of RuvBL1 impairs adenovirus growth but does not appear to significantly affect viral protein expression. Although RuvBL1 has been shown to play a role in cell growth, its depletion had no effect on the ability of the virus to replicate its genome or to drive cells into S phase. E1A was found to bind to RuvBL1 via the C terminus of E1A, and this interaction was important for suppression of interferon-stimulated gene transcriptional activation and recruitment of E1A to interferon-regulated promoters. Here, we report the identification of RuvBL1 as a new target for adenovirus in its quest to suppress the interferon response.IMPORTANCE For most viruses, suppression of the interferon signaling pathway is crucial to ensure a successful replicative cycle. Human adenovirus has evolved several different mechanisms that prevent activation of interferon or the ability of the cell to respond to interferon. The viral immediate-early gene E1A was previously shown to affect interferon signaling in several different ways. Here, we report a novel mechanism reliant on RuvBL1 that E1A uses to prevent activation of interferon-stimulated gene expression following infection or interferon treatment. This adds to the growing knowledge of how viruses are able to inhibit interferon and identifies a novel target used by adenovirus for modulation of the cellular interferon pathway.
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25
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Frost JR, Olanubi O, Cheng SKH, Soriano A, Crisostomo L, Lopez A, Pelka P. The interaction of adenovirus E1A with the mammalian protein Ku70/XRCC6. Virology 2016; 500:11-21. [PMID: 27769014 DOI: 10.1016/j.virol.2016.10.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 09/30/2016] [Accepted: 10/06/2016] [Indexed: 11/30/2022]
Abstract
Human adenovirus infects terminally differentiated cells and to replicate it must induce S-phase. The chief architects that drive adenovirus-infected cells into S-phase are the E1A proteins, with 5 different isoforms expressed during infection. E1A remodels the infected cell by associating with cellular factors and modulating their activity. The C-terminus of E1A is known to bind to only a handful of proteins. We have identified a novel E1A C-terminus binding protein, Ku70 (XRCC6), which was found to bind directly within the CR4 of E1A from human adenovirus type 5. Depletion of Ku70 reduced virus growth, possibly by activating the DNA damage response pathway. Ku70 was found to localize to viral replication centers and associate with the viral genome. Ku70 was also recruited to cellular cell cycle regulated promoters following viral infection. Our study has identified, for the first time, Ku70 as a novel E1A-binding protein which affects virus life cycle.
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Affiliation(s)
- Jasmine Rae Frost
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Buller Building Room 427, Winnipeg, MB, Canada, R3T 2N2
| | - Oladunni Olanubi
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Buller Building Room 427, Winnipeg, MB, Canada, R3T 2N2
| | | | - Andrea Soriano
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Buller Building Room 427, Winnipeg, MB, Canada, R3T 2N2
| | - Leandro Crisostomo
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Buller Building Room 427, Winnipeg, MB, Canada, R3T 2N2
| | - Alennie Lopez
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Buller Building Room 427, Winnipeg, MB, Canada, R3T 2N2
| | - Peter Pelka
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Buller Building Room 427, Winnipeg, MB, Canada, R3T 2N2.
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26
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Hošek T, Calçada EO, Nogueira MO, Salvi M, Pagani TD, Felli IC, Pierattelli R. Structural and Dynamic Characterization of the Molecular Hub Early Region 1A (E1A) from Human Adenovirus. Chemistry 2016; 22:13010-3. [PMID: 27490777 DOI: 10.1002/chem.201602510] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Indexed: 12/19/2022]
Abstract
The small-DNA human adenovirus encodes one of the most versatile molecular hubs, the E1A protein. This protein is essential for productive viral infection in human cells and a vast amount of biologically relevant data are available on its interactions with host proteins. Up to now, however, no high-resolution structural and dynamic information on E1A is available despite its important biological role. Among the different spliced variants of E1A, two are expressed at high level in the early stage of infection. These are 243 and 289 residues isoforms. Herein, we present their NMR characterization, showing that they are both highly disordered, but also demonstrate a certain heterogeneous behavior in terms of structural and dynamic properties. Furthermore, we present the characterization of the isolated domain of the longer variant, known as CR3. This study opens the way to understanding at the molecular level how E1A functions.
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Affiliation(s)
- Tomáš Hošek
- CERM and Department of Chemistry "Ugo Schiff", University of Florence, via Luigi Sacconi 6, 50019, Sesto Fiorentino, Italy
| | - Eduardo O Calçada
- CERM and Department of Chemistry "Ugo Schiff", University of Florence, via Luigi Sacconi 6, 50019, Sesto Fiorentino, Italy
| | - Marcela Oliveira Nogueira
- CERM and Department of Chemistry "Ugo Schiff", University of Florence, via Luigi Sacconi 6, 50019, Sesto Fiorentino, Italy
| | - Michele Salvi
- CERM and Department of Chemistry "Ugo Schiff", University of Florence, via Luigi Sacconi 6, 50019, Sesto Fiorentino, Italy
| | - Talita Duarte Pagani
- CERM and Department of Chemistry "Ugo Schiff", University of Florence, via Luigi Sacconi 6, 50019, Sesto Fiorentino, Italy
| | - Isabella C Felli
- CERM and Department of Chemistry "Ugo Schiff", University of Florence, via Luigi Sacconi 6, 50019, Sesto Fiorentino, Italy.
| | - Roberta Pierattelli
- CERM and Department of Chemistry "Ugo Schiff", University of Florence, via Luigi Sacconi 6, 50019, Sesto Fiorentino, Italy.
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The Dual Nature of Nek9 in Adenovirus Replication. J Virol 2015; 90:1931-43. [PMID: 26676776 DOI: 10.1128/jvi.02392-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 11/25/2015] [Indexed: 01/10/2023] Open
Abstract
UNLABELLED To successfully replicate in an infected host cell, a virus must overcome sophisticated host defense mechanisms. Viruses, therefore, have evolved a multitude of devices designed to circumvent cellular defenses that would lead to abortive infection. Previous studies have identified Nek9, a cellular kinase, as a binding partner of adenovirus E1A, but the biology behind this association remains a mystery. Here we show that Nek9 is a transcriptional repressor that functions together with E1A to silence the expression of p53-inducible GADD45A gene in the infected cell. Depletion of Nek9 in infected cells reduces virus growth but unexpectedly enhances viral gene expression from the E2 transcription unit, whereas the opposite occurs when Nek9 is overexpressed. Nek9 localizes with viral replication centers, and its depletion reduces viral genome replication, while overexpression enhances viral genome numbers in infected cells. Additionally, Nek9 was found to colocalize with the viral E4 orf3 protein, a repressor of cellular stress response. Significantly, Nek9 was also shown to associate with viral and cellular promoters and appears to function as a transcriptional repressor, representing the first instance of Nek9 playing a role in gene regulation. Overall, these results highlight the complexity of virus-host interactions and identify a new role for the cellular protein Nek9 during infection, suggesting a role for Nek9 in regulating p53 target gene expression. IMPORTANCE In the arms race that exists between a pathogen and its host, each has continually evolved mechanisms to either promote or prevent infection. In order to successfully replicate and spread, a virus must overcome every mechanism that a cell can assemble to block infection. On the other hand, to counter viral spread, cells must have multiple mechanisms to stifle viral replication. In the present study, we add to our understanding of how the human adenovirus is able to circumvent cellular roadblocks to replication. We show that the virus uses a cellular protein, Nek9, in order to block activation of p53-regulated gene GADD45A, which is an important player in stress response and p53-mediated cell cycle arrest. Importantly, our study also identifies Nek9 as a transcriptional repressor.
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