1
|
Després GD, Ngo K, Lemay G. The μ2 and λ1 Proteins of Mammalian Reovirus Modulate Early Events Leading to Induction of the Interferon Signaling Network. Viruses 2022; 14:v14122638. [PMID: 36560642 PMCID: PMC9780918 DOI: 10.3390/v14122638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022] Open
Abstract
It has been previously shown that amino acid polymorphisms in reovirus proteins μ2 and λ1 are associated with differing levels of interferon induction. In the present study, viruses carrying these polymorphisms in either or both proteins, were further studied. The two viral determinants exert a synergistic effect on the control of β-interferon induction at the protein and mRNA level, with a concomitant increase in RIG-I. In contrast, levels of phospho-Stat1 and interferon-stimulated genes are increased in singly substituted viruses but with no further increase when both substitutions were present. This suggests that the viral determinants are acting during initial events of viral recognition. Accordingly, difference between viruses was reduced when infection was performed with partially uncoated virions (ISVPs) and transfection of RNA recovered from early-infected cells recapitulates the differences between viruses harboring the different polymorphisms. Altogether, the data are consistent with a redundant or complementary role of μ2 and λ1, affecting either early disassembly or the nature of the viral RNA in the incoming viral particle. Proteins involved in viral RNA synthesis are thus involved in this likely critical aspect of the ability of different reovirus variants to infect various cell types, and to discriminate between parental and transformed/cancer cells.
Collapse
|
2
|
Unexpected Genetic Diversity of Two Novel Swine MRVs in Italy. Viruses 2020; 12:v12050574. [PMID: 32456089 PMCID: PMC7290992 DOI: 10.3390/v12050574] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/06/2020] [Accepted: 05/21/2020] [Indexed: 12/22/2022] Open
Abstract
Mammalian Orthoreoviruses (MRV) are segmented dsRNA viruses in the family Reoviridae. MRVs infect mammals and cause asymptomatic respiratory, gastro-enteric and, rarely, encephalic infections. MRVs are divided into at least three serotypes: MRV1, MRV2 and MRV3. In Europe, swine MRV (swMRV) was first isolated in Austria in 1998 and subsequently reported more than fifteen years later in Italy. In the present study, we characterized two novel reassortant swMRVs identified in one same Italian farm over two years. The two viruses shared the same genetic backbone but showed evidence of reassortment in the S1, S4, M2 segments and were therefore classified into two serotypes: MRV3 in 2016 and MRV2 in 2018. A genetic relation to pig, bat and human MRVs and other unknown sources was identified. A considerable genetic diversity was observed in the Italian MRV3 and MRV2 compared to other available swMRVs. The S1 protein presented unique amino acid signatures in both swMRVs, with unexpected frequencies for MRV2. The remaining genes formed distinct and novel genetic groups that revealed a geographically related evolution of swMRVs in Italy. This is the first report of the complete molecular characterization of novel reassortant swMRVs in Italy and Europe, which suggests a greater genetic diversity of swMRVs never identified before.
Collapse
|
3
|
Zainutdinov SS, Kochneva GV, Netesov SV, Chumakov PM, Matveeva OV. Directed evolution as a tool for the selection of oncolytic RNA viruses with desired phenotypes. Oncolytic Virother 2019; 8:9-26. [PMID: 31372363 PMCID: PMC6636189 DOI: 10.2147/ov.s176523] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 06/07/2019] [Indexed: 12/23/2022] Open
Abstract
Viruses have some characteristics in common with cell-based life. They can evolve and adapt to environmental conditions. Directed evolution can be used by researchers to produce viral strains with desirable phenotypes. Through bioselection, improved strains of oncolytic viruses can be obtained that have better safety profiles, increased specificity for malignant cells, and more efficient spread among tumor cells. It is also possible to select strains capable of killing a broader spectrum of cancer cell variants, so as to achieve a higher frequency of therapeutic responses. This review describes and analyses virus adaptation studies performed with members of four RNA virus families that are used for viral oncolysis: reoviruses, paramyxoviruses, enteroviruses, and rhabdoviruses.
Collapse
Affiliation(s)
- Sergei S Zainutdinov
- State Research Center of Virology and Biotechnology “Vector”
, Koltsovo630559, Russia
| | - Galina V Kochneva
- State Research Center of Virology and Biotechnology “Vector”
, Koltsovo630559, Russia
| | - Sergei V Netesov
- Department of Natural Sciences, Novosibirsk State University, Novosibirsk630090, Russia
| | - Peter M Chumakov
- Engelhardt Institute of Molecular Biology
, Moscow119991, Russia
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products
, Moscow108819, Russia
| | | |
Collapse
|
4
|
Lanoie D, Boudreault S, Bisaillon M, Lemay G. How Many Mammalian Reovirus Proteins are involved in the Control of the Interferon Response? Pathogens 2019; 8:E83. [PMID: 31234302 PMCID: PMC6631787 DOI: 10.3390/pathogens8020083] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/17/2019] [Accepted: 06/18/2019] [Indexed: 12/24/2022] Open
Abstract
As with most viruses, mammalian reovirus can be recognized and attacked by the host-cell interferon response network. Similarly, many viruses have developed resistance mechanisms to counteract the host-cell response at different points of this response. Reflecting the complexity of the interferon signaling pathways as well as the resulting antiviral response, viruses can-and often have-evolved many determinants to interfere with this innate immune response and allow viral replication. In the last few years, it has been evidenced that mammalian reovirus encodes many different determinants that are involved in regulating the induction of the interferon response or in interfering with the action of interferon-stimulated gene products. In this brief review, we present our current understanding of the different reovirus proteins known to be involved, introduce their postulated modes of action, and raise current questions that may lead to further investigations.
Collapse
Affiliation(s)
- Delphine Lanoie
- Département de microbiologie, infectiologie et immunologie, Université de Montréal, Montréal, QC H3C 3J7, Canada.
| | - Simon Boudreault
- Département de biochimie, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada.
| | - Martin Bisaillon
- Département de biochimie, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada.
| | - Guy Lemay
- Département de microbiologie, infectiologie et immunologie, Université de Montréal, Montréal, QC H3C 3J7, Canada.
| |
Collapse
|
5
|
Evolution of the Piscine orthoreovirus Genome Linked to Emergence of Heart and Skeletal Muscle Inflammation in Farmed Atlantic Salmon ( Salmo salar). Viruses 2019; 11:v11050465. [PMID: 31121920 PMCID: PMC6563308 DOI: 10.3390/v11050465] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/16/2019] [Accepted: 05/20/2019] [Indexed: 01/09/2023] Open
Abstract
Heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar) was first diagnosed in Norway in 1999. The disease is caused by Piscine orthoreovirus-1 (PRV-1). The virus is prevalent in farmed Atlantic salmon, but not always associated with disease. Phylogeny and sequence analyses of 31 PRV-1 genomes collected over a 30-year period from fish with or without HSMI, grouped the viral sequences into two main monophylogenetic clusters, one associated with HSMI and the other with low virulent PRV-1 isolates. A PRV-1 strain from Norway sampled in 1988, a decade before the emergence of HSMI, grouped with the low virulent HSMI cluster. The two distinct monophylogenetic clusters were particularly evident for segments S1 and M2. Only a limited number of amino acids were unique to the association with HSMI, and they all located to S1 and M2 encoded proteins. The observed co-evolution of the S1-M2 pair coincided in time with the emergence of HSMI in Norway, and may have evolved through accumulation of mutations and/or segment reassortment. Sequences of S1-M2 suggest selection of the HSMI associated pair, and that this segment pair has remained almost unchanged in Norwegian salmon aquaculture since 1997. PRV-1 strains from the North American Pacific Coast and Faroe Islands have not undergone this evolution, and are more closely related to the PRV-1 precursor strains not associated with clinical HSMI.
Collapse
|
6
|
Lanoie D, Côté S, Degeorges E, Lemay G. A single mutation in the mammalian orthoreovirus S1 gene is responsible for increased interferon sensitivity in a virus mutant selected in Vero cells. Virology 2018; 528:73-79. [PMID: 30578938 DOI: 10.1016/j.virol.2018.12.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 12/12/2018] [Accepted: 12/12/2018] [Indexed: 12/24/2022]
Abstract
In a previous study, a mammalian orthoreovirus mutant was isolated based on its increased ability to infect interferon-defective Vero cells and was referred to as Vero-cells-adapted virus (VeroAV). This virus exhibits reduced ability to resist the antiviral effect of interferon. In the present study, the complete genome sequence of VeroAV was first determined. Reverse genetics was then used to identify a unique mutation on the S1 gene, overlapping the σ1 and σ1 s reading frame, resulting in increased sensitivity to interferon. A virus lacking σ1 s expression consecutive to mutation of its initiation codon was then shown to exhibit a further increase in sensitivity to interferon, supporting the idea that σ1 s is the viral protein responsible. This identification of a new determinant of reovirus sensitivity to interferon gives credentials to the idea that multiple reovirus genes are responsible for the level of interferon induction and susceptibility to the interferon-induced antiviral activities.
Collapse
Affiliation(s)
- Delphine Lanoie
- Département de microbiologie, infectiologie et immunologie, Université de Montréal, Montréal, Canada H3C 3J7
| | - Stéphanie Côté
- Département de microbiologie, infectiologie et immunologie, Université de Montréal, Montréal, Canada H3C 3J7
| | - Emmanuelle Degeorges
- Département de microbiologie, infectiologie et immunologie, Université de Montréal, Montréal, Canada H3C 3J7
| | - Guy Lemay
- Département de microbiologie, infectiologie et immunologie, Université de Montréal, Montréal, Canada H3C 3J7.
| |
Collapse
|
7
|
Lemay G. Synthesis and Translation of Viral mRNA in Reovirus-Infected Cells: Progress and Remaining Questions. Viruses 2018; 10:E671. [PMID: 30486370 PMCID: PMC6315682 DOI: 10.3390/v10120671] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 11/23/2018] [Accepted: 11/25/2018] [Indexed: 12/11/2022] Open
Abstract
At the end of my doctoral studies, in 1988, I published a review article on the major steps of transcription and translation during the mammalian reovirus multiplication cycle, a topic that still fascinates me 30 years later. It is in the nature of scientific research to generate further questioning as new knowledge emerges. Our understanding of these fascinating viruses thus remains incomplete but it seemed appropriate at this moment to look back and reflect on our progress and most important questions that still puzzle us. It is also essential of being careful about concepts that seem so well established, but could still be better validated using new approaches. I hope that the few reflections presented here will stimulate discussions and maybe attract new investigators into the field of reovirus research. Many other aspects of the viral multiplication cycle would merit our attention. However, I will essentially limit my discussion to these central aspects of the viral cycle that are transcription of viral genes and their phenotypic expression through the host cell translational machinery. The objective here is not to review every aspect but to put more emphasis on important progress and challenges in the field.
Collapse
Affiliation(s)
- Guy Lemay
- Département de microbiologie, infectiologie et immunologie, Université de Montréal, Montréal, QC H3C 3J7, Canada.
| |
Collapse
|
8
|
Protein Mismatches Caused by Reassortment Influence Functions of the Reovirus Capsid. J Virol 2018; 92:JVI.00858-18. [PMID: 30068646 DOI: 10.1128/jvi.00858-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 07/26/2018] [Indexed: 12/22/2022] Open
Abstract
Following attachment to host receptors via σ1, reovirus particles are endocytosed and disassembled to generate infectious subvirion particles (ISVPs). ISVPs undergo conformational changes to form ISVP*, releasing σ1 and membrane-targeting peptides from the viral μ1 protein. ISVP* formation is required for delivery of the viral core into the cytoplasm for replication. We characterized the properties of T3DF/T3DCS1, an S1 gene monoreassortant between two laboratory isolates of prototype reovirus strain T3D: T3DF and T3DC T3DF/T3DCS1 is poorly infectious. This deficiency is a consequence of inefficient encapsidation of S1-encoded σ1 on T3DF/T3DCS1 virions. Additionally, compared to T3DF, T3DF/T3DCS1 undergoes ISVP-to-ISVP* conversion more readily, revealing an unexpected role for σ1 in regulating ISVP* formation. The σ1 protein is held within turrets formed by the λ2 protein. To test if the altered properties of T3DF/T3DCS1 are due to a mismatch between σ1 and λ2 proteins from T3DF and T3DC, properties of T3DF/T3DCL2 and T3DF/T3DCS1L2, which express a T3DC-derived λ2, were compared. The presence of T3DC λ2 allowed more efficient σ1 incorporation, producing particles that exhibit T3DF-like infectivity. Compared to T3DF, T3DF/T3DCL2 prematurely converts to ISVP*, uncovering a role for λ2 in regulating ISVP* formation. Importantly, a virus with matching σ1 and λ2 displayed a more regulated conversion to ISVP* than either T3DF/T3DCS1 or T3DF/T3DCL2. In addition to identifying new regulators of ISVP* formation, our results highlight that protein mismatches produced by reassortment can alter virus assembly and thereby influence subsequent functions of the virus capsid.IMPORTANCE Cells coinfected with viruses that possess a multipartite or segmented genome reassort to produce progeny viruses that contain a combination of gene segments from each parent. Reassortment places new pairs of genes together, generating viruses in which mismatched proteins must function together. To test if such forced pairing of proteins that form the virus shell or capsid alters the function of the particle, we investigated properties of reovirus variants in which the σ1 attachment protein and the λ2 protein that anchors σ1 on the particle are mismatched. Our studies demonstrate that a σ1-λ2 mismatch produces particles with lower levels of encapsidated σ1, consequently decreasing virus attachment and infectivity. The mismatch between σ1 and λ2 also altered the capacity of the viral capsid to undergo conformational changes required for cell entry. These studies reveal new functions of reovirus capsid proteins and illuminate both predictable and novel implications of reassortment.
Collapse
|
9
|
Lanoie D, Lemay G. Multiple proteins differing between laboratory stocks of mammalian orthoreoviruses affect both virus sensitivity to interferon and induction of interferon production during infection. Virus Res 2018; 247:40-46. [PMID: 29382551 DOI: 10.1016/j.virusres.2018.01.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 01/20/2018] [Accepted: 01/21/2018] [Indexed: 12/19/2022]
Abstract
In the course of previous works, it was observed that the virus laboratory stock (T3DS) differs in sequence from the virus encoded by the ten plasmids currently in use in many laboratories (T3DK), and derived from a different original virus stock. Seven proteins are affected by these sequence differences. In the present study, replication of T3DK was shown to be more sensitive to the antiviral effect of interferon. Infection by the T3DK virus was also shown to induce the production of higher amount of β and α-interferons compared to T3DS. Two proteins, the μ2 and λ2 proteins, were found to be responsible for increased sensitivity to interferon while both μ2 and λ1 are responsible for increased interferon secretion. Altogether this supports the idea that multiple reovirus proteins are involved in the control of induction of interferon and virus sensitivity to the interferon-induced response. While interrelated, interferon induction and sensitivity can be separated by defined gene combinations. While both μ2 and λ2 were previously suspected of a role in the control of the interferon response, other proteins are also likely involved, as first shown here for λ1. This also further stresses that due caution should be exerted when comparing different virus isolates with different genetic background.
Collapse
Affiliation(s)
- Delphine Lanoie
- Département de microbiologie, infectiologie et immunologie, Université de Montréal, Montréal, H3C 3J7, Canada
| | - Guy Lemay
- Département de microbiologie, infectiologie et immunologie, Université de Montréal, Montréal, H3C 3J7, Canada.
| |
Collapse
|
10
|
African Swine Fever Virus NP868R Capping Enzyme Promotes Reovirus Rescue during Reverse Genetics by Promoting Reovirus Protein Expression, Virion Assembly, and RNA Incorporation into Infectious Virions. J Virol 2017; 91:JVI.02416-16. [PMID: 28298603 DOI: 10.1128/jvi.02416-16] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 03/07/2017] [Indexed: 12/25/2022] Open
Abstract
Reoviruses, like many eukaryotic viruses, contain an inverted 7-methylguanosine (m7G) cap linked to the 5' nucleotide of mRNA. The traditional functions of capping are to promote mRNA stability, protein translation, and concealment from cellular proteins that recognize foreign RNA. To address the role of mRNA capping during reovirus replication, we assessed the benefits of adding the African swine fever virus NP868R capping enzyme during reovirus rescue. C3P3, a fusion protein containing T7 RNA polymerase and NP868R, was found to increase protein expression 5- to 10-fold compared to T7 RNA polymerase alone while enhancing reovirus rescue from the current reverse genetics system by 100-fold. Surprisingly, RNA stability was not increased by C3P3, suggesting a direct effect on protein translation. A time course analysis revealed that C3P3 increased protein synthesis within the first 2 days of a reverse genetics transfection. This analysis also revealed that C3P3 enhanced processing of outer capsid μ1 protein to μ1C, a previously described hallmark of reovirus assembly. Finally, to determine the rate of infectious-RNA incorporation into new virions, we developed a new recombinant reovirus S1 gene that expressed the fluorescent protein UnaG. Following transfection of cells with UnaG and infection with wild-type virus, passage of UnaG through progeny was significantly enhanced by C3P3. These data suggest that capping provides nontraditional functions to reovirus, such as promoting assembly and infectious-RNA incorporation.IMPORTANCE Our findings expand our understanding of how viruses utilize capping, suggesting that capping provides nontraditional functions to reovirus, such as promoting assembly and infectious-RNA incorporation, in addition to enhancing protein translation. Beyond providing mechanistic insight into reovirus replication, our findings also show that reovirus reverse genetics rescue is enhanced 100-fold by the NP868R capping enzyme. Since reovirus shows promise as a cancer therapy, efficient reovirus reverse genetics rescue will accelerate production of recombinant reoviruses as candidates to enhance therapeutic potency. NP868R-assisted reovirus rescue will also expedite production of recombinant reovirus for mechanistic insights into reovirus protein function and structure.
Collapse
|
11
|
James KT, Cooney B, Agopsowicz K, Trevors MA, Mohamed A, Stoltz D, Hitt M, Shmulevitz M. Novel High-throughput Approach for Purification of Infectious Virions. Sci Rep 2016; 6:36826. [PMID: 27827454 PMCID: PMC5101806 DOI: 10.1038/srep36826] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 10/21/2016] [Indexed: 01/02/2023] Open
Abstract
Viruses are extensively studied as pathogens and exploited as molecular tools and therapeutic agents. Existing methods to purify viruses such as gradient ultracentrifugation or chromatography have limitations, for example demand for technical expertise or specialized equipment, high time consumption, and restricted capacity. Our laboratory explores mutations in oncolytic reovirus that could improve oncolytic activity, and makes routine use of numerous virus variants, genome reassortants, and reverse engineered mutants. Our research pace was limited by the lack of high-throughput virus purification methods that efficiently remove confounding cellular contaminants such as cytokines and proteases. To overcome this shortcoming, we evaluated a commercially available resin (Capto Core 700) that captures molecules smaller than 700 kDa. Capto. Core 700 chromatography produced virion purity and infectivity indistinguishable from CsCl density gradient ultracentrifugation as determined by electron microscopy, gel electrophoresis analysis and plaque titration. Capto Core 700 resin was then effectively adapted to a rapid in-slurry pull-out approach for high-throughput purification of reovirus and adenovirus. The in-slurry purification approach offered substantially increased virus purity over crude cell lysates, media, or high-spin preparations and would be especially useful for high-throughput virus screening applications where density gradient ultracentrifugation is not feasible.
Collapse
Affiliation(s)
- Kevin T James
- Department of Medical Microbiology and Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta, Canada
| | - Brad Cooney
- GE Healthcare, LifeSciences, Marlborough, MA, US
| | - Kate Agopsowicz
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Mary Ann Trevors
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Adil Mohamed
- Department of Medical Microbiology and Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta, Canada
| | - Don Stoltz
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Mary Hitt
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Maya Shmulevitz
- Department of Medical Microbiology and Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
12
|
Mohamed A, Johnston RN, Shmulevitz M. Potential for Improving Potency and Specificity of Reovirus Oncolysis with Next-Generation Reovirus Variants. Viruses 2015; 7:6251-78. [PMID: 26633466 PMCID: PMC4690860 DOI: 10.3390/v7122936] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Revised: 11/10/2015] [Accepted: 11/18/2015] [Indexed: 12/16/2022] Open
Abstract
Viruses that specifically replicate in tumor over normal cells offer promising cancer therapies. Oncolytic viruses (OV) not only kill the tumor cells directly; they also promote anti-tumor immunotherapeutic responses. Other major advantages of OVs are that they dose-escalate in tumors and can be genetically engineered to enhance potency and specificity. Unmodified wild type reovirus is a propitious OV currently in phase I–III clinical trials. This review summarizes modifications to reovirus that may improve potency and/or specificity during oncolysis. Classical genetics approaches have revealed reovirus variants with improved adaptation towards tumors or with enhanced ability to establish specific steps of virus replication and cell killing among transformed cells. The recent emergence of a reverse genetics system for reovirus has provided novel strategies to fine-tune reovirus proteins or introduce exogenous genes that could promote oncolytic activity. Over the next decade, these findings are likely to generate better-optimized second-generation reovirus vectors and improve the efficacy of oncolytic reotherapy.
Collapse
Affiliation(s)
- Adil Mohamed
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2E1, Canada.
| | - Randal N Johnston
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
| | - Maya Shmulevitz
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2E1, Canada.
| |
Collapse
|