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Collective interactions augment influenza A virus replication in a host-dependent manner. Nat Microbiol 2020; 5:1158-1169. [PMID: 32632248 PMCID: PMC7484227 DOI: 10.1038/s41564-020-0749-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 06/01/2020] [Indexed: 11/08/2022]
Abstract
Infection with a single influenza A virus (IAV) is only rarely sufficient to initiate productive infection. Instead, multiple viral genomes are often required in a given cell. Here, we show that the reliance of IAV on multiple infection can form an important species barrier. Namely, we find that avian H9N2 viruses representative of those circulating widely at the poultry-human interface exhibit acute dependence on collective interactions in mammalian systems. This need for multiple infection is greatly reduced in the natural host. Quantification of incomplete viral genomes showed that their complementation accounts for the moderate reliance on multiple infection seen in avian cells but not the added reliance seen in mammalian cells. An additional form of virus-virus interaction is needed in mammals. We find that the PA gene segment is a major driver of this phenotype and that both viral replication and transcription are affected. These data indicate that multiple distinct mechanisms underlie the reliance of IAV on multiple infection and underscore the importance of virus-virus interactions in IAV infection, evolution and emergence.
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2
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Drayman N, Ben-Nun-Shaul O, Butin-Israeli V, Srivastava R, Rubinstein AM, Mock CS, Elyada E, Ben-Neriah Y, Lahav G, Oppenheim A. p53 elevation in human cells halt SV40 infection by inhibiting T-ag expression. Oncotarget 2018; 7:52643-52660. [PMID: 27462916 PMCID: PMC5288138 DOI: 10.18632/oncotarget.10769] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 07/14/2016] [Indexed: 11/25/2022] Open
Abstract
SV40 large T-antigen (T-ag) has been known for decades to inactivate the tumor suppressor p53 by sequestration and additional mechanisms. Our present study revealed that the struggle between p53 and T-ag begins very early in the infection cycle. We found that p53 is activated early after SV40 infection and defends the host against the infection. Using live cell imaging and single cell analyses we found that p53 dynamics are variable among individual cells, with only a subset of cells activating p53 immediately after SV40 infection. This cell-to-cell variabilty had clear consequences on the outcome of the infection. None of the cells with elevated p53 at the beginning of the infection proceeded to express T-ag, suggesting a p53-dependent decision between abortive and productive infection. In addition, we show that artificial elevation of p53 levels prior to the infection reduces infection efficiency, supporting a role for p53 in defending against SV40. We further found that the p53-mediated host defense mechanism against SV40 is not facilitated by apoptosis nor via interferon-stimulated genes. Instead p53 binds to the viral DNA at the T-ag promoter region, prevents its transcriptional activation by Sp1, and halts the progress of the infection. These findings shed new light on the long studied struggle between SV40 T-ag and p53, as developed during virus-host coevolution. Our studies indicate that the fate of SV40 infection is determined as soon as the viral DNA enters the nucleus, before the onset of viral gene expression.
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Affiliation(s)
- Nir Drayman
- Department of Hematology, Hebrew University Faculty of Medicine and Hadassah University Hospital, Jerusalem, Israel.,Department of Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Orly Ben-Nun-Shaul
- Department of Hematology, Hebrew University Faculty of Medicine and Hadassah University Hospital, Jerusalem, Israel
| | - Veronika Butin-Israeli
- Department of Hematology, Hebrew University Faculty of Medicine and Hadassah University Hospital, Jerusalem, Israel
| | - Rohit Srivastava
- Department of Hematology, Hebrew University Faculty of Medicine and Hadassah University Hospital, Jerusalem, Israel
| | - Ariel M Rubinstein
- Department of Hematology, Hebrew University Faculty of Medicine and Hadassah University Hospital, Jerusalem, Israel
| | - Caroline S Mock
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Ela Elyada
- The Lautenberg Center for Immunology and Cancer Research, Hebrew University Faculty of Medicine, Jerusalem, Israel
| | - Yinon Ben-Neriah
- The Lautenberg Center for Immunology and Cancer Research, Hebrew University Faculty of Medicine, Jerusalem, Israel
| | - Galit Lahav
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Ariella Oppenheim
- Department of Hematology, Hebrew University Faculty of Medicine and Hadassah University Hospital, Jerusalem, Israel
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3
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Bauman Y, Drayman N, Ben-Nun-Shaul O, Vitenstein A, Yamin R, Ophir Y, Oppenheim A, Mandelboim O. Downregulation of the stress-induced ligand ULBP1 following SV40 infection confers viral evasion from NK cell cytotoxicity. Oncotarget 2017; 7:15369-81. [PMID: 26992229 PMCID: PMC4941247 DOI: 10.18632/oncotarget.8085] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 02/23/2016] [Indexed: 12/21/2022] Open
Abstract
Polyomaviruses are a diverse family of viruses which are prevalent in the human population. However, the interactions of these viruses with the immune system are not well characterized. We have previously shown that two human polyomaviruses, JC and BK, use an identical microRNA to evade immune attack by Natural Killer (NK) cells. We showed that this viral microRNA suppresses ULBP3 expression, a stress induced ligand for the killer receptor NKG2D. Here we show that Simian Virus 40 (SV40) also evades NK cell attack through the down regulation of another stress-induced ligand of NKG2D, ULBP1. These findings indicate that NK cells play an essential role in fighting polyomavirus infections and further emphasize the importance of various members of the ULBP family in controlling polyomavirus infection.
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Affiliation(s)
- Yoav Bauman
- The Lautenberg Center for General and Tumor Immunology, The BioMedical Research Institute Israel-Canada of The Faculty of Medicine (IMRIC), The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Nir Drayman
- Department of Hematology Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Orly Ben-Nun-Shaul
- Department of Hematology Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Alon Vitenstein
- The Lautenberg Center for General and Tumor Immunology, The BioMedical Research Institute Israel-Canada of The Faculty of Medicine (IMRIC), The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Rachel Yamin
- The Lautenberg Center for General and Tumor Immunology, The BioMedical Research Institute Israel-Canada of The Faculty of Medicine (IMRIC), The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Yael Ophir
- The Lautenberg Center for General and Tumor Immunology, The BioMedical Research Institute Israel-Canada of The Faculty of Medicine (IMRIC), The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Ariella Oppenheim
- Department of Hematology Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ofer Mandelboim
- The Lautenberg Center for General and Tumor Immunology, The BioMedical Research Institute Israel-Canada of The Faculty of Medicine (IMRIC), The Hebrew University Hadassah Medical School, Jerusalem, Israel
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4
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Tsai YC, Tsai TH, Chang CP, Chen SF, Lee YM, Shyue SK. Linear correlation between average fluorescence intensity of green fluorescent protein and the multiplicity of infection of recombinant adenovirus. J Biomed Sci 2015; 22:31. [PMID: 25971314 PMCID: PMC4430915 DOI: 10.1186/s12929-015-0137-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 04/21/2015] [Indexed: 11/27/2022] Open
Abstract
Background Adenoviral vector is an efficient tool for gene transfer. Protein expression is regulated by a number of factors, but the regulation by gene copy number remains to be investigated further. Results Assessed by flow cytometry, we demonstrated a significant linear correlation between average fluorescence intensity of green fluorescent protein (GFP) and a wide range of multiplicity of infection (MOI), spanning from 0.01 to 200. Average GFP intensity was calculated by mean fluorescence intensity (MFI) × percentage of infection (POI) (MFI × POI) and the correlation was observed in cells transduced with GFP-expressing adenoviral vector driven either by a cytomegalovirus (CMV) promoter for 3 to 6 h or by a human phosphoglycerate kinase (PGK) promoter for 18 to 24 h. Factors impacting this linear correlation include MOI of viral vector, strength of promoter driving GFP expression, cell type transduced and incubation time after gene transfer. We also found that weak GFP signals could be interfered by background signals, whereas strong GFP signals could overshot the detection limitation of the flow cytometer and resulted in a deviation from linearity which was prevented by adjusting the setting in flow cytometer. Moreover, we compared promoter strength as measured by MFI × POI and found that the relative activity of CMV promoter to PGK promoter was 20 to 47 folds in A549 cells and 32 to > 100 folds in H1299 cells. Conclusions The linear correlation between MFI × POI and a wide range of adenoviral MOI provides an efficient method to investigate factors regulating protein expression and to estimate virus titers. Electronic supplementary material The online version of this article (doi:10.1186/s12929-015-0137-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yi-Chen Tsai
- Graduate School of Life Science, National Defense Medical Center, Taipei, 11490, Taiwan. .,Institute of Biomodical Sciences, Academia Sinica, No. 128, Sec. 2, Academia Road, Taipei, 11529, Taiwan.
| | - Tsung-Huang Tsai
- Institute of Biomodical Sciences, Academia Sinica, No. 128, Sec. 2, Academia Road, Taipei, 11529, Taiwan.
| | - Chen-Ping Chang
- Institute of Biomodical Sciences, Academia Sinica, No. 128, Sec. 2, Academia Road, Taipei, 11529, Taiwan.
| | - Shu-Fen Chen
- Institute of Biomodical Sciences, Academia Sinica, No. 128, Sec. 2, Academia Road, Taipei, 11529, Taiwan.
| | - Yen-Ming Lee
- Graduate School of Life Science, National Defense Medical Center, Taipei, 11490, Taiwan. .,Institute of Biomodical Sciences, Academia Sinica, No. 128, Sec. 2, Academia Road, Taipei, 11529, Taiwan.
| | - Song-Kun Shyue
- Graduate School of Life Science, National Defense Medical Center, Taipei, 11490, Taiwan. .,Institute of Biomodical Sciences, Academia Sinica, No. 128, Sec. 2, Academia Road, Taipei, 11529, Taiwan. .,School of Chinese Medicine, China Medical University, Taichung, 40402, Taiwan.
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5
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Chen CJ, Burke JM, Kincaid RP, Azarm KD, Mireles N, Butel JS, Sullivan CS. Naturally arising strains of polyomaviruses with severely attenuated microRNA expression. J Virol 2014; 88:12683-93. [PMID: 25142594 PMCID: PMC4248899 DOI: 10.1128/jvi.01933-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 08/14/2014] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED Several different polyomaviruses (PyVs) encode microRNAs (miRNAs) that regulate viral as well as host gene expression. However, the functions of polyomaviral miRNAs, particularly during in vivo infection, remain poorly understood. Here we identify rare naturally arising PyVs that are severely attenuated or null for miRNA expression. We identify hypomorphic or null strains for miRNA expression from rhesus macaque simian virus 40 (SV40) and human JC virus. These strains were isolated from immunocompromised hosts and derive from insertions or deletions in the viral DNA that preserve the amino acid reading frame of opposing-strand large T antigen gene. Characterization of the SV40 miRNA hypomorph, K661, shows that it is inhibited at the early miRNA biogenesis step of Drosha-mediated processing. Despite having a nonrearranged enhancer, which a previous study has shown renders some PyVs more susceptible to the autoregulatory activities of the miRNA, restoring miRNA expression to K661 has little effect on virus growth in either immortalized or primary monkey kidney cells. Thus, in addition to any effect of accompanying genomic elements, these results suggest that the cellular context also determines susceptibility to PyV miRNA-mediated effects. Combined, these results demonstrate that polyomaviruses lacking miRNAs can arise infrequently and that the functional importance of polyomaviral miRNAs is context dependent, consistent with an activity connected to the immune status of the host. IMPORTANCE Diverse virus families encode miRNAs, yet much remains unknown about viral miRNA function and contribution to the infectious cycle. Polyomaviruses (PyVs) are small DNA viruses, long known to be important as etiological agents of rare diseases and valuable models of DNA virus infection. Here, in immunosuppressed hosts, we uncover rare naturally arising variants of different PyVs that have lost the ability to express miRNAs. This represents some of the only known natural viruses to have lost miRNA expression. By probing the biogenesis pathways of these variants, we uncover that miRNA expression is lost via small insertions or deletions that render the transcripts resistant to early steps of miRNA biogenesis while preserving the reading frame of the opposing T antigen transcripts. Overall, our study informs how miRNA genes evolve/devolve in viruses and suggests that miRNA function is exquisitely dependent not only on viral genomic context but also on the cellular and host environment.
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Affiliation(s)
- Chun Jung Chen
- The University of Texas at Austin, Institute for Cellular and Molecular Biology, Department of Molecular Biosciences, Center for Systems and Synthetic Biology, Center for Infectious Disease, Austin, Texas, USA
| | - James M Burke
- The University of Texas at Austin, Institute for Cellular and Molecular Biology, Department of Molecular Biosciences, Center for Systems and Synthetic Biology, Center for Infectious Disease, Austin, Texas, USA
| | - Rodney P Kincaid
- The University of Texas at Austin, Institute for Cellular and Molecular Biology, Department of Molecular Biosciences, Center for Systems and Synthetic Biology, Center for Infectious Disease, Austin, Texas, USA
| | - Kristopher D Azarm
- The University of Texas at Austin, Institute for Cellular and Molecular Biology, Department of Molecular Biosciences, Center for Systems and Synthetic Biology, Center for Infectious Disease, Austin, Texas, USA
| | - Noel Mireles
- American Chemical Society Project SEED Summer Internship Program, James Bowie High School, Austin, Texas, USA
| | - Janet S Butel
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - Christopher S Sullivan
- The University of Texas at Austin, Institute for Cellular and Molecular Biology, Department of Molecular Biosciences, Center for Systems and Synthetic Biology, Center for Infectious Disease, Austin, Texas, USA
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6
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Drayman N, Glick Y, Ben-nun-shaul O, Zer H, Zlotnick A, Gerber D, Schueler-Furman O, Oppenheim A. Pathogens use structural mimicry of native host ligands as a mechanism for host receptor engagement. Cell Host Microbe 2014; 14:63-73. [PMID: 23870314 DOI: 10.1016/j.chom.2013.05.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 04/04/2013] [Accepted: 05/03/2013] [Indexed: 11/25/2022]
Abstract
A pathogen's ability to engage host receptors is a critical determinant of its host range and interspecies transmissibility, key issues for understanding emerging diseases. However, the identification of host receptors, which are also attractive drug targets, remains a major challenge. Our structural bioinformatics studies reveal that both bacterial and viral pathogens have evolved to structurally mimic native host ligands (ligand mimicry), thus enabling engagement of their cognate host receptors. In contrast to the structural homology, amino acid sequence similarity between pathogen molecules and the mimicked host ligands was low. We illustrate the utility of this concept to identify pathogen receptors by delineating receptor tyrosine kinase Axl as a candidate receptor for the polyomavirus SV40. The SV40-Axl interaction was validated, and its participation in the infection process was verified. Our results suggest that ligand mimicry is widespread, and we present a quick tool to screen for pathogen-host receptor interactions.
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Affiliation(s)
- Nir Drayman
- Department of Haematology, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
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7
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Chen CJ, Cox JE, Kincaid RP, Martinez A, Sullivan CS. Divergent MicroRNA targetomes of closely related circulating strains of a polyomavirus. J Virol 2013; 87:11135-47. [PMID: 23926342 PMCID: PMC3807300 DOI: 10.1128/jvi.01711-13] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 07/30/2013] [Indexed: 11/20/2022] Open
Abstract
Hundreds of virus-encoded microRNAs (miRNAs) have been uncovered, but an in-depth functional understanding is lacking for most. A major challenge for the field is separating those miRNA targets that are biologically relevant from those that are not advantageous to the virus. Here, we show that miRNAs from related variants of the polyomavirus simian vacuolating virus 40 (SV40) have differing host target repertoires (targetomes) while their direct autoregulatory activity on virus-encoded early gene products is completely preserved. These results underscore the importance of miRNA-mediated viral gene autoregulation in some polyomavirus life cycles. More broadly, these findings imply that some host targets of virus-encoded miRNAs are likely to be of little selective advantage to the virus, and our approach provides a strategy for prioritizing relevant targets.
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Affiliation(s)
- Chun Jung Chen
- The University of Texas at Austin, Molecular Genetics & Microbiology, Austin, Texas, USA
| | - Jennifer E. Cox
- The University of Texas at Austin, Molecular Genetics & Microbiology, Austin, Texas, USA
| | - Rodney P. Kincaid
- The University of Texas at Austin, Molecular Genetics & Microbiology, Austin, Texas, USA
| | - Angel Martinez
- American Chemical Society Project SEED Summer Internship Program, James Bowie High School, Austin, Texas, USA
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8
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Giorda KM, Raghava S, Zhang MW, Hebert DN. The viroporin activity of the minor structural proteins VP2 and VP3 is required for SV40 propagation. J Biol Chem 2012; 288:2510-20. [PMID: 23223228 DOI: 10.1074/jbc.m112.428425] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
For nonenveloped viruses such as Simian Virus 40, the mechanism used to translocate viral components across membranes is poorly understood. Previous results indicated that the minor structural proteins, VP2 and VP3, might act as membrane proteins during infection. Here, purified VP2 and VP3 were found to form pores in host cell membranes. To identify possible membrane domains, individual hydrophobic domains from VP2 and VP3 were expressed in a model protein and tested for their ability to integrate into membranes. Several domains from the late proteins supported endoplasmic reticulum membrane insertion as transmembrane domains. Mutations in VP2 and VP3 were engineered that inhibited membrane insertion and pore formation. When these mutations were introduced into the viral genome, viral propagation was inhibited. This comprehensive approach revealed that the viroporin activity of VP2 and VP3 was inhibited by targeted disruptions of individual hydrophobic domains and the loss of membrane disruption activity impaired viral infection.
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Affiliation(s)
- Kristina M Giorda
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003, USA
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9
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Kobiler O, Drayman N, Butin-Israeli V, Oppenheim A. Virus strategies for passing the nuclear envelope barrier. Nucleus 2012; 3:526-39. [PMID: 22929056 PMCID: PMC3515536 DOI: 10.4161/nucl.21979] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Viruses that replicate in the nucleus need to pass the nuclear envelope barrier during infection. Research in recent years indicates that the nuclear envelope is a major hurdle for many viruses. This review describes strategies to overcome this obstacle developed by seven virus families: herpesviridae, adenoviridae, orthomyxoviridae, lentiviruses (which are part of retroviridae), Hepadnaviridae, parvoviridae and polyomaviridae. Most viruses use the canonical nuclear pore complex (NPC) in order to get their genome into the nucleus. Viral capsids that are larger than the nuclear pore disassemble before or during passing through the NPC, thus allowing genome nuclear entry. Surprisingly, increasing evidence suggest that parvoviruses and polyomaviruses may bypass the nuclear pore by trafficking directly through the nuclear membrane. Additional studies are required for better understanding these processes. Since nuclear entry emerges as the limiting step in infection for many viruses, it may serve as an ideal target for antiviral drug development.
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Affiliation(s)
- Oren Kobiler
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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10
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Abstract
Traditionally, the most common methods used to titrate virus stocks are the plaque assay and the hemagglutination assay. The protocol presented here is based on the detection of viral-expressed proteins in infected cells by flow cytometry. It is simpler and more rapid than the traditional plaque-forming assay and it enables high-throughput analyses.
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Affiliation(s)
- Nir Drayman
- Department of Hematology, Hadassah Medical School, The Hebrew University of Jerusalem, Jerusalem, Israel
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11
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Grigorov B, Rabilloud J, Lawrence P, Gerlier D. Rapid titration of measles and other viruses: optimization with determination of replication cycle length. PLoS One 2011; 6:e24135. [PMID: 21915289 PMCID: PMC3168471 DOI: 10.1371/journal.pone.0024135] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2011] [Accepted: 08/02/2011] [Indexed: 02/01/2023] Open
Abstract
Background Measles virus (MV) is a member of the Paramyxoviridae family and an important human pathogen causing strong immunosuppression in affected individuals and a considerable number of deaths worldwide. Currently, measles is a re-emerging disease in developed countries. MV is usually quantified in infectious units as determined by limiting dilution and counting of plaque forming unit either directly (PFU method) or indirectly from random distribution in microwells (TCID50 method). Both methods are time-consuming (up to several days), cumbersome and, in the case of the PFU assay, possibly operator dependent. Methods/Findings A rapid, optimized, accurate, and reliable technique for titration of measles virus was developed based on the detection of virus infected cells by flow cytometry, single round of infection and titer calculation according to the Poisson's law. The kinetics follow up of the number of infected cells after infection with serial dilutions of a virus allowed estimation of the duration of the replication cycle, and consequently, the optimal infection time. The assay was set up to quantify measles virus, vesicular stomatitis virus (VSV), and human immunodeficiency virus type 1 (HIV-1) using antibody labeling of viral glycoprotein, virus encoded fluorescent reporter protein and an inducible fluorescent-reporter cell line, respectively. Conclusion Overall, performing the assay takes only 24–30 hours for MV strains, 12 hours for VSV, and 52 hours for HIV-1. The step-by-step procedure we have set up can be, in principle, applicable to accurately quantify any virus including lentiviral vectors, provided that a virus encoded gene product can be detected by flow cytometry.
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Affiliation(s)
- Boyan Grigorov
- INSERM, U758, Ecole Normale Supérieure de Lyon, Lyon, France, Université de Lyon, Lyon, France.
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12
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Butin-Israeli V, Ben-nun-Shaul O, Kopatz I, Adam SA, Shimi T, Goldman RD, Oppenheim A. Simian virus 40 induces lamin A/C fluctuations and nuclear envelope deformation during cell entry. Nucleus 2011; 2:320-30. [PMID: 21941111 PMCID: PMC3260569 DOI: 10.4161/nucl.2.4.16371] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2011] [Revised: 06/27/2011] [Accepted: 07/02/2011] [Indexed: 12/25/2022] Open
Abstract
The canonical gate of viruses and viral genomes into the nucleus in non-dividing cells is the nuclear pore, embedded within the nuclear envelope. However, we found that for SV40, the nuclear envelope poses a major hurdle to infection: FISH analysis revealed that the majority of viral DNA remains trapped in the ER; silencing of Lamin A/C rendered the cells more susceptible to infection; and proliferating cells are more susceptible to infection than quiescent cells. Surprisingly, we observed that following SV40 infection the nuclear envelope, including lamins A/C, B1, B2 and the nuclear pore complex, was dramatically deformed, as seen by immunohistochemistry. The infection induced fluctuations in the level of lamin A/C, dephosphorylation of an unknown epitope and leakage to the cytoplasm just prior to and during nuclear entry. Deformations were transient, and the spherical structure of the nuclear envelope was restored subsequent to nuclear entry. Nuclear envelope deformations and lamin A/C dephosphorylation depended on caspase-6 cleavage of lamin A/C. Notably, we have previously reported that inhibition of caspase-6 abolishes SV40 infection. Taken together the results suggest that alterations of the nuclear lamina, induced by the infecting virus, are involved in the nuclear entry of the SV40 genome. We propose that SV40 utilize this unique, previously unknown mechanism for direct trafficking of its genome from the ER to the nucleus. As SV40 serves as a paradigm for the pathogenic human BK, JC and Merkel cell polyomavirus, this study suggests nuclear entry as a novel drug target for these infections.
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Affiliation(s)
- Veronika Butin-Israeli
- Department of Hematology; Hebrew University-Hadassah Medical School; Jerusalem, Israel
- Department of Cell and Molecular Biology; Feinberg School of Medicine; Northwestern University; Chicago, IL USA
| | - Orly Ben-nun-Shaul
- Department of Hematology; Hebrew University-Hadassah Medical School; Jerusalem, Israel
| | - Idit Kopatz
- Department of Hematology; Hebrew University-Hadassah Medical School; Jerusalem, Israel
| | - Stephen A Adam
- Department of Cell and Molecular Biology; Feinberg School of Medicine; Northwestern University; Chicago, IL USA
| | - Takeshi Shimi
- Department of Cell and Molecular Biology; Feinberg School of Medicine; Northwestern University; Chicago, IL USA
| | - Robert D Goldman
- Department of Cell and Molecular Biology; Feinberg School of Medicine; Northwestern University; Chicago, IL USA
| | - Ariella Oppenheim
- Department of Hematology; Hebrew University-Hadassah Medical School; Jerusalem, Israel
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