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Devaux CA, Pontarotti P, Levasseur A, Colson P, Raoult D. Is it time to switch to a formulation other than the live attenuated poliovirus vaccine to prevent poliomyelitis? Front Public Health 2024; 11:1284337. [PMID: 38259741 PMCID: PMC10801389 DOI: 10.3389/fpubh.2023.1284337] [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: 08/28/2023] [Accepted: 12/14/2023] [Indexed: 01/24/2024] Open
Abstract
The polioviruses (PVs) are mainly transmitted by direct contact with an infected person through the fecal-oral route and respiratory secretions (or more rarely via contaminated water or food) and have a primary tropism for the gut. After their replication in the gut, in rare cases (far less than 1% of the infected individuals), PVs can spread to the central nervous system leading to flaccid paralysis, which can result in respiratory paralysis and death. By the middle of the 20th century, every year the wild polioviruses (WPVs) are supposed to have killed or paralyzed over half a million people. The introduction of the oral poliovirus vaccines (OPVs) through mass vaccination campaigns (combined with better application of hygiene measures), was a success story which enabled the World Health Organization (WHO) to set the global eradication of poliomyelitis as an objective. However this strategy of viral eradication has its limits as the majority of poliomyelitis cases today arise in individuals infected with circulating vaccine-derived polioviruses (cVDPVs) which regain pathogenicity following reversion or recombination. In recent years (between January 2018 and May 2023), the WHO recorded 8.8 times more cases of polio which were linked to the attenuated OPV vaccines (3,442 polio cases after reversion or recombination events) than cases linked to a WPV (390 cases). Recent knowledge of the evolution of RNA viruses and the exchange of genetic material among biological entities of the intestinal microbiota, call for a reassessment of the polio eradication vaccine strategies.
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Affiliation(s)
- Christian Albert Devaux
- Laboratory Microbes Evolution Phylogeny and Infection (MEPHI), Aix-Marseille Université, IRD, APHM, Institut Hospitalo-Universitaire Méditerranée Infection, Marseille, France
- Centre National de la Recherche Scientifique (CNRS-SNC5039), Marseille, France
| | - Pierre Pontarotti
- Laboratory Microbes Evolution Phylogeny and Infection (MEPHI), Aix-Marseille Université, IRD, APHM, Institut Hospitalo-Universitaire Méditerranée Infection, Marseille, France
- Centre National de la Recherche Scientifique (CNRS-SNC5039), Marseille, France
| | - Anthony Levasseur
- Laboratory Microbes Evolution Phylogeny and Infection (MEPHI), Aix-Marseille Université, IRD, APHM, Institut Hospitalo-Universitaire Méditerranée Infection, Marseille, France
| | - Philippe Colson
- Laboratory Microbes Evolution Phylogeny and Infection (MEPHI), Aix-Marseille Université, IRD, APHM, Institut Hospitalo-Universitaire Méditerranée Infection, Marseille, France
| | - Didier Raoult
- Laboratory Microbes Evolution Phylogeny and Infection (MEPHI), Aix-Marseille Université, IRD, APHM, Institut Hospitalo-Universitaire Méditerranée Infection, Marseille, France
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Teterina NL, Levenson E, Rinaudo MS, Egger D, Bienz K, Gorbalenya AE, Ehrenfeld E. Evidence for functional protein interactions required for poliovirus RNA replication. J Virol 2007; 80:5327-37. [PMID: 16699013 PMCID: PMC1472133 DOI: 10.1128/jvi.02684-05] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Poliovirus protein 2C contains a predicted N-terminal amphipathic helix that mediates association of the protein with the membranes of the viral RNA replication complex. A chimeric virus that contains sequences encoding the 18-residue core from the orthologous amphipathic helix from human rhinovirus type 14 (HRV14) was constructed. The chimeric virus exhibited defects in viral RNA replication and produced minute plaques on HeLa cell monolayers. Large plaque variants that contained mutations within the 2C-encoding region were generated upon subsequent passage. However, the majority of viruses that emerged with improved growth properties contained no changes in the region encoding 2C. Sequence analysis and reconstruction of genomes with individual mutations revealed changes in 3A or 2B sequences that compensated for the HRV14 amphipathic helix in the polio 2C-containing proteins, implying functional interactions among these proteins during the replication process. Direct binding between these viral proteins was confirmed by mammalian cell two-hybrid analysis.
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Affiliation(s)
- Natalya L Teterina
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases/NIH, Bldg. 50, 50 South Drive, Bethesda, MD 20892-8011, USA
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Abstract
Replication of poliovirus RNA is accomplished by the error-prone viral RNA-dependent RNA polymerase and hence is accompanied by numerous mutations. In addition, genetic errors may be introduced by nonreplicative mechanisms. Resulting variability is manifested by point mutations and genomic rearrangements (e.g., deletions, insertions and recombination). After description of basic mechanisms underlying this variability, the review focuses on regularities of poliovirus evolution (mutation fixation) in tissue cultures, human organisms and populations.
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Affiliation(s)
- V I Agol
- M.P. Chumakov Institute of Poliomyelitis and Viral Encephalitides, Russian Academy of Medical Sciences, 142782, Russia.
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Teterina NL, Gorbalenya AE, Egger D, Bienz K, Rinaudo MS, Ehrenfeld E. Testing the modularity of the N-terminal amphipathic helix conserved in picornavirus 2C proteins and hepatitis C NS5A protein. Virology 2005; 344:453-67. [PMID: 16226781 PMCID: PMC7111807 DOI: 10.1016/j.virol.2005.08.044] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2005] [Revised: 08/04/2005] [Accepted: 08/24/2005] [Indexed: 01/06/2023]
Abstract
The N-terminal region of the picornaviral 2C protein is predicted to fold into an amphipathic α-helix that is responsible for the protein's association with membranes in the viral RNA replication complex. We have identified a similar sequence in the N-terminal region of NS5A of hepaciviruses that was recently shown to form an amphipathic α-helix. The conservation of the N-terminal region in two apparently unrelated proteins of two different RNA virus families suggested that this helix might represent an independent module. To test this hypothesis, we constructed chimeric poliovirus (PV) genomes in which the sequence encoding the N-terminal 2C amphipathic helix was replaced by orthologous sequences from other picornaviral genomes or a similar sequence from NS5A of HCV. Effects of the mutations were assessed by measuring the accumulation of viable virus and viral RNA in HeLa cells after transfection, examining membrane morphology in cells expressing chimeric proteins and by in vitro analysis of RNA translation, protein processing and negative strand RNA synthesis in HeLa cell extracts. The chimeras manifested a wide range of growth and RNA synthesis phenotypes. The results are compatible with our hypothesis, although they demonstrate that helix exchangeability may be restricted due to requirements for interactions with other viral components involved in virus replication.
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Affiliation(s)
- Natalya L Teterina
- Laboratory of Infectious Diseases, LID, NIAID, NIH, Bldg. 50, Room 6122, 50 South Drive, Bethesda, MD 20892-8011, USA.
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Hunziker IP, Harkins S, Feuer R, Cornell CT, Whitton JL. Generation and analysis of an RNA vaccine that protects against coxsackievirus B3 challenge. Virology 2005; 330:196-208. [PMID: 15527846 DOI: 10.1016/j.virol.2004.09.035] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2004] [Accepted: 09/26/2004] [Indexed: 01/25/2023]
Abstract
Coxsackievirus B3 (CVB3) is an important human pathogen that causes substantial morbidity and mortality but, to date, no vaccine is available. We have generated an RNA-based vaccine against CVB3 and have evaluated it in the murine model of infection. The vaccine was designed to allow production of the viral polyprotein, which should be cleaved to generate most of the viral proteins in their mature form; but infectious virus should not be produced. In vitro translation studies indicated that the mutant polyprotein was efficiently translated and was processed as expected. The mutant RNA was not amplified in transfected cells, and infectious particles were not produced. Furthermore, the candidate RNA vaccine appeared safe in vivo, causing no detectable pathology following injection. Finally, despite failing to induce detectable neutralizing antibodies, the candidate RNA vaccine conferred substantial protection against virus challenge, either with an attenuated recombinant CVB3, or with the highly pathogenic wt virus.
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Affiliation(s)
- Isabelle P Hunziker
- Department of Neuropharmacology, CVN-9, The Scripps Research Institute, La Jolla, CA 92037, USA
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Abstract
Enteroviruses, members of the Picornaviridae family, comprise a large (over 70 serotypes) group of viruses that are ubiquitous in nature, infect different species and cause a wide range of diseases. Human enteroviruses were recently classified into five species, human enterovirus A-D and poliovirus. Recombination has long been known to be an important property of poliovirus genetics. Recently, several publications demonstrated that recombination is extremely frequent also in non-polio enteroviruses, and allows independent evolution of enterovirus genome fragments even on a microevolutionary scale. Prototype enterovirus strains were shown to have complex phylogenetic relations, and almost all modern enterovirus isolates turned out to be recombinants compared with the prototype strains. Recombination takes place strictly between members of the same species, and usually spares the capsid-encoding genome region. Therefore, it can be concluded that the enterovirus species exist as a worldwide reservoir of genetic material comprising a limited quantity of capsid gene sets defining a finite number of serotypes and a range of non-structural genes that recombine frequently to produce new virus variants. This new model of enterovirus genetics helps to explain the failure of previous attempts to connect serotype and disease profile in non-polio enteroviruses, and seriously questions existing typing approaches that are based solely on the capsid-encoding genome region. It remains to be determined what role recombination plays in the emergence of new enterovirus variants and in the macroevolution of animal enteroviruses and viruses of the picorna-like supergroup.
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Affiliation(s)
- Alexander N Lukashev
- Chumakov Institute of Poliomyelitis and Viral Encephalitides RAMS, Moscow, Russia.
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de Jong AS, Melchers WJG, Glaudemans DHRF, Willems PHGM, van Kuppeveld FJM. Mutational analysis of different regions in the coxsackievirus 2B protein: requirements for homo-multimerization, membrane permeabilization, subcellular localization, and virus replication. J Biol Chem 2004; 279:19924-35. [PMID: 14976211 DOI: 10.1074/jbc.m314094200] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The coxsackievirus 2B protein is a small hydrophobic protein (99 amino acids) that increases host cell membrane permeability, possibly by forming homo-multimers that build membrane-integral pores. Previously, we defined the functional role of the two hydrophobic regions HR1 and HR2. Here, we investigated the importance of regions outside HR1 and HR2 for multimerization, increasing membrane permeability, subcellular localization, and virus replication through analysis of linker insertion and substitution mutants. From these studies, the following conclusions could be drawn. (i) The hydrophilic region ((58)RNHDD(62)) between HR1 and HR2 is critical for multimerization and increasing membrane permeability. Substitution analysis of Asn(61) and Asn(62) demonstrated the preference for short polar side chains (Asp, Asn), residues that are often present in turns, over long polar side chains (Glu, Gln). This finding supports the idea that the hydrophilic region is involved in pore formation by facilitating a turn between HR1 and HR2 to reverse chain direction. (ii) Studies undertaken to define the downstream boundary of HR2 demonstrated that the aromatic residues Trp(80) and Trp(82), but not the positively charged residues Arg(81), Lys(84), and Lys(86) are important for increasing membrane permeability. (iii) The N terminus is not required for multimerization but does contribute to the membrane-active character of 2B. (iv) The subcellular localization of 2B does not rely on regions outside HR1 and HR2 and does not require multimerization. (v) Virus replication requires both the membrane-active character and an additional function of 2B that is not connected to this activity.
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Affiliation(s)
- Arjan S de Jong
- Department of Medical Microbiology, Nijmegen Center for Molecular Life Sciences, University Medical Center Nijmegen, 6500 HB Nijmegen, The Netherlands
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Towner JS, Brown DM, Nguyen JHC, Semler BL. Functional conservation of the hydrophobic domain of polypeptide 3AB between human rhinovirus and poliovirus. Virology 2003; 314:432-42. [PMID: 14517095 DOI: 10.1016/s0042-6822(03)00448-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In this study we exchanged portions of the poliovirus type 1 (PV1) hydrophobic domain within the membrane-associated polypeptide 3AB for the analogous sequences from human rhinovirus 14 (HRV14). The sequence exchanges were based upon a previous report in which the 22 amino acid hydrophobic region was subdivided into two domains, I and II, the latter of which was shown to be required for membrane association (J. Biol. Chem. 271 (1996), 26810). Using these divisions, the HRV14 sequences were cloned into the complete poliovirus type 1 cDNA sequence. RNAs transcribed from these cDNAs were transfected into HeLa cell monolayers and used in HeLa cell-free translation/replication assays. The data indicated that 3AB sequences from PV1 and HRV14 are interchangeable; however, the substitutions cause a range of significant RNA replication defects, and in some cases, protein processing defects. Following transfection of RNAs encoding the domain substitutions into HeLa cell monolayers, virus isolates were harvested, and the corresponding viral RNAs were sequenced. The sequence data revealed that for the carboxy-terminal domain substitutions (domain II), multiple nucleotide changes were identified in the first, second, and third positions of different codons. In addition, the data indicated that for one of the PV1/HRV14 chimeras to replicate, compensatory mutations within poliovirus protein 2B may be required.
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Affiliation(s)
- Jonathan S Towner
- Department of Microbiology and Molecular Genetics, College of Medicine, University of California, Irvine, CA 92697, USA
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van Kuppeveld FJM, Melchers WJG, Willems PHGM, Gadella TWJ. Homomultimerization of the coxsackievirus 2B protein in living cells visualized by fluorescence resonance energy transfer microscopy. J Virol 2002; 76:9446-56. [PMID: 12186926 PMCID: PMC136438 DOI: 10.1128/jvi.76.18.9446-9456.2002] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The 2B protein of enteroviruses is the viral membrane-active protein that is responsible for the modifications in host cell membrane permeability that take place in enterovirus-infected cells. The 2B protein shows structural similarities to the group of lytic polypeptides, polypeptides that permeate membranes either by forming multimeric membrane-integral pores or, alternatively, by lying parallel to the lipid bilayer and disturbing the curvature and symmetry of the membrane. Our aim is to gain more insight into the molecular architecture of the 2B protein in vivo. In this study, the possible existence of multimers of the coxsackie B3 virus 2B protein in single living cells was explored by fluorescence resonance energy transfer (FRET) microscopy. FRET between fusion proteins 2B-ECFP and 2B-EYFP (enhanced cyan and yellow fluorescent variants of green fluorescent protein) was monitored by using spectral imaging microscopy (SPIM) and fluorescence lifetime imaging microscopy (FLIM). Both techniques revealed the occurrence of intermolecular FRET between 2B-ECFP and 2B-EYFP, providing evidence for the formation of protein 2B homomultimers. Putative models for the mode of action of the membrane-active 2B protein and the formation of membrane-integral pores by 2B multimers are discussed.
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Affiliation(s)
- Frank J M van Kuppeveld
- Department of Medical Microbiology, University Medical Center Nijmegen, 6500 HB Nijmegen, The Netherlands.
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de Jong AS, Schrama IWJ, Willems PHGM, Galama JMD, Melchers WJG, van Kuppeveld FJM. Multimerization reactions of coxsackievirus proteins 2B, 2C and 2BC: a mammalian two-hybrid analysis. J Gen Virol 2002; 83:783-793. [PMID: 11907327 DOI: 10.1099/0022-1317-83-4-783] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recently, homomultimerization and heteromultimerization reactions of the poliovirus P2 region proteins were investigated using a yeast two-hybrid approach (Cuconati et al., Journal of Virology 72, 1297-1307, 1998). In this study, we investigated multimerization reactions of the 2B, 2C and 2BC proteins of the closely related coxsackie B3 virus (CBV3) using a mammalian two-hybrid system. This system allows the characterization of protein:protein interactions within a cellular environment that more closely mimics the native protein environment. Homomultimerization reactions were observed with the 2BC protein and, albeit weakly, with the 2B protein, but not with the 2C protein. To identify the determinants involved in the 2BC and 2B homomultimerization reactions, several mutants containing deletions or point mutations in the 2B region were tested. Disruption of the hydrophobic character of either the cationic amphipathic alpha-helix or the second hydrophobic domain of the 2B protein disturbed both the 2BC:2BC and the 2B:2B homomultimerization reactions. Disruption of either the cationic or the amphipathic character of the alpha-helix or deletion of the N-terminal 30 amino acids of the 2B protein, however, had no effect on the 2BC and 2B homomultimerization reactions. Heteromultimerization reactions were observed between proteins 2BC and 2B, and also between proteins 2BC and 2C, but not between the 2B and 2C proteins. The 2BC:2B and 2BC:2C heteromultimerization reactions were also mediated by hydrophobic determinants located in the amphipathic alpha-helix and the second hydrophobic domain. The nature of the interactions and their implications for the virus life-cycle are discussed.
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Affiliation(s)
- Arjan S de Jong
- Departments of Medical Microbiology1 and Biochemistry2, Nijmegen Center for Molecular Life Sciences, University Medical Center Nijmegen, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Ina W J Schrama
- Departments of Medical Microbiology1 and Biochemistry2, Nijmegen Center for Molecular Life Sciences, University Medical Center Nijmegen, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Peter H G M Willems
- Departments of Medical Microbiology1 and Biochemistry2, Nijmegen Center for Molecular Life Sciences, University Medical Center Nijmegen, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Jochem M D Galama
- Departments of Medical Microbiology1 and Biochemistry2, Nijmegen Center for Molecular Life Sciences, University Medical Center Nijmegen, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Willem J G Melchers
- Departments of Medical Microbiology1 and Biochemistry2, Nijmegen Center for Molecular Life Sciences, University Medical Center Nijmegen, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Frank J M van Kuppeveld
- Departments of Medical Microbiology1 and Biochemistry2, Nijmegen Center for Molecular Life Sciences, University Medical Center Nijmegen, PO Box 9101, 6500 HB Nijmegen, The Netherlands
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Clark AJ, Bertens P, Wellink J, Shanks M, Lomonossoff GP. Studies on hybrid comoviruses reveal the importance of three-dimensional structure for processing of the viral coat proteins and show that the specificity of cleavage is greater in trans than in cis. Virology 1999; 263:184-94. [PMID: 10544093 DOI: 10.1006/viro.1999.9947] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A series of cowpea mosaic virus (CPMV)-based hybrid comoviral RNA-2 molecules have been constructed. In these, the region encoding both the large (L) and small (S) viral coat proteins was replaced by the equivalent region from bean pod mottle virus (BPMV). The hybrid RNA-2 molecules were able to replicate in cowpea protoplasts in the presence of CPMV RNA-1. Though processing of the hybrid polyproteins by the CPMV-specific 24K proteinase at the site between the 58/48K and L proteins could readily be achieved, no processing at the site between the L and S coat proteins could be obtained even when the sequence of amino acids between the two coat proteins was made CPMV-like. As a result, none of the hybrids was able to form functional virus particles, and they could not infect cowpea plants. Comparison with the processing of the L-S site in cis in reticulocyte lysates demonstrated that the requirements for processing are more stringent in trans than in cis. The results suggest that the L-S cleavage site is defined by more than just a linear sequence of amino acids and probably involves interactions between the L-S loop and the beta barrels of the viral coat proteins.
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Affiliation(s)
- A J Clark
- Department of Virus Research, John Innes Centre, Colney Lane, Norwich, NR4 7UH, United Kingdom
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Santti J, Hyypiä T, Kinnunen L, Salminen M. Evidence of recombination among enteroviruses. J Virol 1999; 73:8741-9. [PMID: 10482628 PMCID: PMC112895 DOI: 10.1128/jvi.73.10.8741-8749.1999] [Citation(s) in RCA: 192] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/1999] [Accepted: 07/06/1999] [Indexed: 11/20/2022] Open
Abstract
Human enteroviruses consist of more than 60 serotypes, reflecting a wide range of evolutionary divergence. They have been genetically classified into four clusters on the basis of sequence homology in the coding region of the single-stranded RNA genome. To explore further the genetic relationships between human enteroviruses and to characterize the evolutionary mechanisms responsible for variation, previously sequenced genomes were subjected to detailed comparison. Bootstrap and genetic similarity analyses were used to systematically scan the alignments of complete genomic sequences. Bootstrap analysis provided evidence from an early recombination event at the junction of the 5' noncoding and coding regions of the progenitors of the current clusters. Analysis within the genetic clusters indicated that enterovirus prototype strains include intraspecies recombinants. Recombination breakpoints were detected in all genomic regions except the capsid protein coding region. Our results suggest that recombination is a significant and relatively frequent mechanism in the evolution of enterovirus genomes.
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Affiliation(s)
- J Santti
- MediCity Research Laboratory and Department of Virology, University of Turku, FIN-20520 Turku, National Public Health Institute, FIN-00300 Helsinki, Finland.
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Bolten R, Egger D, Gosert R, Schaub G, Landmann L, Bienz K. Intracellular localization of poliovirus plus- and minus-strand RNA visualized by strand-specific fluorescent In situ hybridization. J Virol 1998; 72:8578-85. [PMID: 9765396 PMCID: PMC110268 DOI: 10.1128/jvi.72.11.8578-8585.1998] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The time courses of poliovirus plus- and minus-strand RNA synthesis in infected HEp-2 cells were monitored separately, using a quantitative RNase assay. In parallel, viral RNA and proteins were located in situ by confocal microscopy within cells fixed by a protocol determined to retain their native size and shape. Plus- and minus-strand RNAs were visualized by fluorescent in situ hybridization (FISH) with strand-specific riboprobes. The probes were labelled with different fluorochromes to allow for the simultaneous detection of plus- and minus-strand RNA. The FISH experiments showed minus-strand RNA to be present in distinct, regularly sized, round structures throughout the viral replication cycle. Plus-strand RNA was found in the same structures and also in smaller clusters of vesicles. Association of viral RNA with membranes was demonstrated by combining FISH with immunofluorescence (IF) detection of the viral 2B- and 2C-containing P2 proteins, which are known to be markers for virus-induced membranes. At early times postinfection, the virus-induced membranous structures were distributed through most of the cytoplasm, whereas around peak RNA synthesis, both RNA-associated membranous structures migrated to the center of the cell. During this process, the plus- and minus-strand-containing larger structures stayed as recognizable entities, whereas the plus-strand-containing granules coalesced into a juxtanuclear area of membranous vesicles. An involvement of Golgi-derived membranes in the formation of virus-induced vesicles and RNA synthesis early in infection was investigated by IF with 2C- and Golgi-specific antibodies.
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Affiliation(s)
- R Bolten
- Institute for Medical Microbiology, University of Basel, Basel, Switzerland
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