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Swaminath S, Russell AB. The use of single-cell RNA-seq to study heterogeneity at varying levels of virus-host interactions. PLoS Pathog 2024; 20:e1011898. [PMID: 38236826 PMCID: PMC10796064 DOI: 10.1371/journal.ppat.1011898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2024] Open
Abstract
The outcome of viral infection depends on the diversity of the infecting viral population and the heterogeneity of the cell population that is infected. Until almost a decade ago, the study of these dynamic processes during viral infection was challenging and limited to certain targeted measurements. Presently, with the use of single-cell sequencing technology, the complex interface defined by the interactions of cells with infecting virus can now be studied across the breadth of the transcriptome in thousands of individual cells simultaneously. In this review, we will describe the use of single-cell RNA sequencing (scRNA-seq) to study the heterogeneity of viral infections, ranging from individual virions to the immune response between infected individuals. In addition, we highlight certain key experimental limitations and methodological decisions that are critical to analyzing scRNA-seq data at each scale.
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Affiliation(s)
- Sharmada Swaminath
- School of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Alistair B. Russell
- School of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
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2
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Bhat T, Cao A, Yin J. Virus-like Particles: Measures and Biological Functions. Viruses 2022; 14:383. [PMID: 35215979 PMCID: PMC8877645 DOI: 10.3390/v14020383] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 02/10/2022] [Accepted: 02/10/2022] [Indexed: 12/25/2022] Open
Abstract
Virus-like particles resemble infectious virus particles in size, shape, and molecular composition; however, they fail to productively infect host cells. Historically, the presence of virus-like particles has been inferred from total particle counts by microscopy, and infectious particle counts or plaque-forming-units (PFUs) by plaque assay; the resulting ratio of particles-to-PFUs is often greater than one, easily 10 or 100, indicating that most particles are non-infectious. Despite their inability to hijack cells for their reproduction, virus-like particles and the defective genomes they carry can exhibit a broad range of behaviors: interference with normal virus growth during co-infections, cell killing, and activation or inhibition of innate immune signaling. In addition, some virus-like particles become productive as their multiplicities of infection increase, a sign of cooperation between particles. Here, we review established and emerging methods to count virus-like particles and characterize their biological functions. We take a critical look at evidence for defective interfering virus genomes in natural and clinical isolates, and we review their potential as antiviral therapeutics. In short, we highlight an urgent need to better understand how virus-like genomes and particles interact with intact functional viruses during co-infection of their hosts, and their impacts on the transmission, severity, and persistence of virus-associated diseases.
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Affiliation(s)
| | | | - John Yin
- Department of Chemical and Biological Engineering, Wisconsin Institute for Discovery, University of Wisconsin-Madison, 330 N. Orchard Street, Madison, WI 53715, USA; (T.B.); (A.C.)
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3
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Mendes M, Russell AB. Library-based analysis reveals segment and length dependent characteristics of defective influenza genomes. PLoS Pathog 2021; 17:e1010125. [PMID: 34882752 PMCID: PMC8691639 DOI: 10.1371/journal.ppat.1010125] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 12/21/2021] [Accepted: 11/17/2021] [Indexed: 12/14/2022] Open
Abstract
Found in a diverse set of viral populations, defective interfering particles are parasitic variants that are unable to replicate on their own yet rise to relatively high frequencies. Their presence is associated with a loss of population fitness, both through the depletion of key cellular resources and the stimulation of innate immunity. For influenza A virus, these particles contain large internal deletions in the genomic segments which encode components of the heterotrimeric polymerase. Using a library-based approach, we comprehensively profile the growth and replication of defective influenza species, demonstrating that they possess an advantage during genome replication, and that exclusion during population expansion reshapes population composition in a manner consistent with their final, observed, distribution in natural populations. We find that an innate immune response is not linked to the size of a deletion; however, replication of defective segments can enhance their immunostimulatory properties. Overall, our results address several key questions in defective influenza A virus biology, and the methods we have developed to answer those questions may be broadly applied to other defective viruses.
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Affiliation(s)
- Marisa Mendes
- Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Alistair B. Russell
- Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
- * E-mail:
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4
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Ghorbani A, Ngunjiri JM, Lee CW. Influenza A Virus Subpopulations and Their Implication in Pathogenesis and Vaccine Development. Annu Rev Anim Biosci 2019; 8:247-267. [PMID: 31479617 DOI: 10.1146/annurev-animal-021419-083756] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The concept of influenza A virus (IAV) subpopulations emerged approximately 75 years ago, when Preben von Magnus described "incomplete" virus particles that interfere with the replication of infectious virus. It is now widely accepted that infectious particles constitute only a minor portion of biologically active IAV subpopulations. The IAV quasispecies is an extremely diverse swarm of biologically and genetically heterogeneous particle subpopulations that collectively influence the evolutionary fitness of the virus. This review summarizes the current knowledge of IAV subpopulations, focusing on their biologic and genomic diversity. It also discusses the potential roles IAV subpopulations play in virus pathogenesis and live attenuated influenza vaccine development.
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Affiliation(s)
- Amir Ghorbani
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, Ohio 44691, USA; , , .,Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - John M Ngunjiri
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, Ohio 44691, USA; , ,
| | - Chang-Won Lee
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, Ohio 44691, USA; , , .,Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210, USA
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5
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Tabata KV, Minagawa Y, Kawaguchi Y, Ono M, Moriizumi Y, Yamayoshi S, Fujioka Y, Ohba Y, Kawaoka Y, Noji H. Antibody-free digital influenza virus counting based on neuraminidase activity. Sci Rep 2019; 9:1067. [PMID: 30705374 PMCID: PMC6355933 DOI: 10.1038/s41598-018-37994-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 12/17/2018] [Indexed: 12/14/2022] Open
Abstract
There is large demand for a quantitative method for rapid and ultra-sensitive detection of the influenza virus. Here, we established a digital influenza virus counting (DIViC) method that can detect a single virion without antibody. In the assay, a virion is stochastically entrapped inside a femtoliter reactor array device for the fluorogenic assay of neuraminidase, and incubated for minutes. By analyzing 600,000 reactors, the practical limit of detection reached the order of 103 (PFU)/mL, only 10-times less sensitive than RT-PCR and more than 1000-times sensitive than commercial rapid test kits (RIDTs). Interestingly, neuraminidase activity differed among virions. The coefficient of variance was 30-40%, evidently broader than that of alkaline phosphatase measured as a model enzyme for comparison, suggesting the heterogeneity in size and integrity among influenza virus particles. Sensitivity to oseltamivir also differed between virions. We also tested DIViC using clinical gargle samples that imposes less burden for sampling while with less virus titre. The comparison with RIDTs showed that DIViC was largely superior to RIDTs in the sensitivity with the clinical samples although a few false-positive signals were observed in some clinical samples that remains as a technical challenge.
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Affiliation(s)
- Kazuhito V Tabata
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Japan.
- ImPACT Program, Cabinet Office, Government of Japan, Chiyoda-ku, Tokyo, 100-8914, Japan.
| | - Yoshihiro Minagawa
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Japan
| | - Yuko Kawaguchi
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Japan
| | - Mana Ono
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Japan
| | - Yoshiki Moriizumi
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Japan
| | - Seiya Yamayoshi
- Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
| | - Yoichiro Fujioka
- Department of Cell Physiology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, N15 W7, Kita-ku, Sapporo, Japan
| | - Yusuke Ohba
- Department of Cell Physiology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, N15 W7, Kita-ku, Sapporo, Japan
| | - Yoshihiro Kawaoka
- Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, 53711, USA
| | - Hiroyuki Noji
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Japan.
- ImPACT Program, Cabinet Office, Government of Japan, Chiyoda-ku, Tokyo, 100-8914, Japan.
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6
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Abstract
Influenza A virus (IAV) continues to pose an enormous and unpredictable global public health threat, largely due to the continual evolution of escape from preexisting immunity and the potential for zoonotic emergence. Understanding how the unique genetic makeup and structure of IAV populations influences their transmission and evolution is essential for developing more-effective vaccines, therapeutics, and surveillance capabilities. Owing to their mutation-prone replicase and unique genome organization, IAV populations exhibit enormous amounts of diversity both in terms of sequence and functional gene content. Here, I review what is currently known about the genetic and genomic diversity present within IAV populations and how this diversity may shape the replicative and evolutionary dynamics of these viruses.
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7
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Huang D, Peng WJ, Ye Q, Liu XP, Zhao L, Fan L, Xia-Hou K, Jia HJ, Luo J, Zhou LT, Li BB, Wang SL, Xu WT, Chen Z, Tan WS. Serum-Free Suspension Culture of MDCK Cells for Production of Influenza H1N1 Vaccines. PLoS One 2015; 10:e0141686. [PMID: 26540170 PMCID: PMC4634975 DOI: 10.1371/journal.pone.0141686] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 10/12/2015] [Indexed: 01/03/2023] Open
Abstract
Development of serum-free suspension cell culture processes is very important for influenza vaccine production. Previously, we developed a MDCK suspension cell line in a serum-free medium. In the present study, the growth kinetics of suspension MDCK cells and influenza virus production in the serum-free medium were investigated, in comparison with those of adherent MDCK cells in both serum-containing and serum-free medium. It was found that the serum-free medium supported the stable subculture and growth of both adherent and suspension cells. In batch culture, for both cell lines, the growth kinetics in the serum-free medium was comparable with those in the serum-containing medium and a commercialized serum-free medium. In the serum-free medium, peak viable cell density (VCD), haemagglutinin (HA) and median tissue culture infective dose (TCID50) titers of the two cell lines reached 4.51×106 cells/mL, 2.94Log10(HAU/50 μL) and 8.49Log10(virions/mL), and 5.97×106 cells/mL, 3.88Log10(HAU/50 μL), and 10.34Log10(virions/mL), respectively. While virus yield of adherent cells in the serum-free medium was similar to that in the serum-containing medium, suspension culture in the serum-free medium showed a higher virus yield than adherent cells in the serum-containing medium and suspension cells in the commercialized serum-free medium. However, the percentage of infectious viruses was lower for suspension culture in the serum-free medium. These results demonstrate the great potential of this suspension MDCK cell line in serum-free medium for influenza vaccine production and further improvements are warranted.
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Affiliation(s)
- Ding Huang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Wen-Juan Peng
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Qian Ye
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Xu-Ping Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
- * E-mail: (X-PL); (W-ST)
| | - Liang Zhao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Li Fan
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Kang Xia-Hou
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Han-Jing Jia
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Jian Luo
- Shanghai Institute of Biological Products Co., Ltd., Shanghai 200052, China
| | - Lin-Ting Zhou
- Shanghai Institute of Biological Products Co., Ltd., Shanghai 200052, China
| | - Bei-Bei Li
- Shanghai Institute of Biological Products Co., Ltd., Shanghai 200052, China
| | - Shi-Lei Wang
- Shanghai Institute of Biological Products Co., Ltd., Shanghai 200052, China
| | - Wen-Ting Xu
- Shanghai Institute of Biological Products Co., Ltd., Shanghai 200052, China
| | - Ze Chen
- Shanghai Institute of Biological Products Co., Ltd., Shanghai 200052, China
| | - Wen-Song Tan
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
- * E-mail: (X-PL); (W-ST)
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8
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Gerber M, Isel C, Moules V, Marquet R. Selective packaging of the influenza A genome and consequences for genetic reassortment. Trends Microbiol 2014; 22:446-55. [PMID: 24798745 DOI: 10.1016/j.tim.2014.04.001] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 03/25/2014] [Accepted: 04/02/2014] [Indexed: 10/25/2022]
Abstract
Influenza A viruses package their segmented RNA genome in a selective manner. Electron tomography, biochemical assays, and replication assays of viruses produced by reverse genetics recently unveiled molecular details of this mechanism, whereby different influenza viral strains form different and unique networks of direct intermolecular RNA-RNA interactions. Together with detailed views of the three-dimensional structure of the viral ribonucleoparticles, these recent advances help us understand the rules that govern genome packaging. They also have deep implications for the genetic reassortment processes, which are responsible for devastating pandemics.
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Affiliation(s)
- Marie Gerber
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Centre National de Recherche Scientifique (CNRS), Institut de Biologie Moléculaire et Cellulaire (IBMC), 15 rue René Descartes, 67084 Strasbourg, France
| | - Catherine Isel
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Centre National de Recherche Scientifique (CNRS), Institut de Biologie Moléculaire et Cellulaire (IBMC), 15 rue René Descartes, 67084 Strasbourg, France
| | - Vincent Moules
- Virologie et Pathologie Humaine, Université Lyon 1, EA4610, Faculté de Médecine RTH Laennec, 69008 Lyon, France; VirNext, Université Lyon 1, EA4610, Faculté de Médecine RTH Laennec, 69008 Lyon, France
| | - Roland Marquet
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Centre National de Recherche Scientifique (CNRS), Institut de Biologie Moléculaire et Cellulaire (IBMC), 15 rue René Descartes, 67084 Strasbourg, France.
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9
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Abstract
Only a small fraction of influenza A virus (IAV) particles within a viral population register as infectious by traditional infectivity assays. Despite constituting the most abundant product of influenza infection, the role that the 'noninfectious' particle fraction plays in the biology of the virus has largely been ignored. This review shines a light on this oft-ignored population by highlighting studies, both old and new, that describe the unique biological activities of these particles, and discussing what this population can tell us about the biology of IAV evolution and disease.
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Affiliation(s)
- Christopher B Brooke
- Laboratory of Viral Diseases, National Institute of Allergy & Infectious Diseases, Bethesda, MD, USA
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10
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Vlecken DH, Pelgrim RP, Ruminski S, Bakker WA, van der Pol LA. Comparison of initial feasibility of host cell lines for viral vaccine production. J Virol Methods 2013; 193:28-41. [DOI: 10.1016/j.jviromet.2013.04.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 04/17/2013] [Accepted: 04/29/2013] [Indexed: 12/28/2022]
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11
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Malinoski CP, Marcus PI. Influenza Virus Subpopulations: Interferon Induction-Suppressing Particles Require Expression of NS1 and Act Globally in Cells; UV Irradiation of Interferon-Inducing Particles Blocks Global Shut-Off and Enhances Interferon Production. J Interferon Cytokine Res 2013; 33:72-9. [DOI: 10.1089/jir.2012.0075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Affiliation(s)
- Christopher P Malinoski
- Department of Molecular and Cell Biology, Virus and Interferon Research Laboratory, University of Connecticut, Storrs, CT 06269, USA
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12
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Abstract
Segmentation of the influenza A virus (IAV) genome enables rapid gene reassortment at the cost of complicating the task of assembling the full viral genome. By simultaneously probing for the expression of multiple viral proteins in MDCK cells infected at a low multiplicity with IAV, we observe that the majority of infected cells lack detectable expression of one or more essential viral proteins. Consistent with this observation, up to 90% of IAV-infected cells fail to release infectious progeny, indicating that many IAV virions scored as noninfectious by traditional infectivity assays are capable of single-round infection. This fraction was not significantly affected by target or producer cell type but varied widely between different IAV strains. These data indicate that IAV exists primarily as a swarm of complementation-dependent semi-infectious virions, and thus traditional, propagation-dependent assays of infectivity may drastically misrepresent the true infectious potential of a virus population.
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13
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Ngunjiri JM, Buchek GM, Mohni KN, Sekellick MJ, Marcus PI. Influenza virus subpopulations: exchange of lethal H5N1 virus NS for H1N1 virus NS triggers de novo generation of defective-interfering particles and enhances interferon-inducing particle efficiency. J Interferon Cytokine Res 2012; 33:99-107. [PMID: 23215782 DOI: 10.1089/jir.2012.0070] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Reassortment of influenza A viruses is known to affect viability, replication efficiency, antigenicity, host range, and virulence, and can generate pandemic strains. In this study, we demonstrated that the specific exchange of the NS gene segment from highly pathogenic A/HK/156/97 (H5N1) [E92 or E92D NS1] virus for the cognate NS gene segment of A/PR/834(H1N1) [D92 NS1] virus did not cause a significant change in the sizes of infectious particle subpopulations. However, it resulted in 2 new phenotypic changes: (1) de novo generation of large subpopulations of defective-interfering particles (DIPs); and (2) enhancement of interferon (IFN)-inducing particle efficiency leading to an order of magnitude or higher quantum (peak) yield of IFN in both avian and mammalian cells. These changes were attributed to loss of function of the H5N1-NS gene products. Most notably, the NS exchange obliterated the usual IFN-induction-suppressing capacity associated with expression of full-size NS1 proteins, and hence functionally mimicked deletions in the NS1 gene. The loss of NS1-mediated suppression of IFN induction, de novo generation of DIPs, and the concomitant enhancement of IFN-inducing particle efficiency suggest that in an attenuated background, the H5N1-NS could be used to formulate a self-adjuvanting live attenuated influenza vaccine similar to viruses with deletions in the NS1 gene.
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Affiliation(s)
- John M Ngunjiri
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA
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14
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Isken B, Genzel Y, Reichl U. Productivity, apoptosis, and infection dynamics of influenza A/PR/8 strains and A/PR/8-based reassortants. Vaccine 2012; 30:5253-61. [PMID: 22698452 DOI: 10.1016/j.vaccine.2012.05.065] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Revised: 05/16/2012] [Accepted: 05/25/2012] [Indexed: 01/18/2023]
Abstract
In cell culture-based influenza vaccine production significant efforts are directed towards virus seed optimization for maximum yields. Typically, high growth reassortants (HGR) containing backbones of six gene segments of e.g. influenza A/PR/8, are generated from wild type strains. Often, however, HA and TCID₅₀ titres obtained do not meet expectations and further optimization measures are required. Flow cytometry is an invaluable tool to improve our understanding of mechanism related to progress of infection, virus-induced apoptosis, and cell-specific productivity. In this study, we performed infections with two influenza A/PR/8 variants (from NIBSC and RKI) and two A/PR/8-based HGRs (Wisconsin-like and Uruguay-like) to investigate virus replication, apoptosis and virus titres at different multiplicities of infection (MOI 0.0001, 0.1, 3). Flow cytometric analyses showed similar dynamics in the time course of infected and apoptotic cell populations for all four tested strains at MOI 0.0001. Interestingly, higher MOI resulted in an earlier increase of the populations of infected and apoptotic cells and showed strain-specific differences. Infections with A/PR/8 NIBSC resulted in an earlier increase in both cell populations compared to A/PR/8 RKI. The Uruguay-like reassortant showed the earliest increase in the concentration of infected cells and a late induction of apoptosis at all tested MOIs. In contrast, the Wisconsin-like reassortant showed strong apoptosis induction at high MOIs resulting in reduced titres compared to lower MOI. Maximum HA titres were unaffected by changes in the MOI for the two A/PR/8 and the Uruguay-like reassortant. Maximum TCID₅₀ titres, however, decreased with increasing MOI for all strains. Overall, infections at very low MOI (0.0001) resulted not only in similar dynamics concerning progress of infection and induction of apoptosis but also in maximum virus yields. Highest HA titres were obtained for virus seed strains combining a fast progress in infection with a late onset of apoptosis. Therefore, both factors should be considered for the establishment of robust influenza vaccine production processes.
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Affiliation(s)
- B Isken
- Max Planck Institute for Dynamics of Complex Technical Systems, Bioprocess Engineering, Sandtorstrasse 1, 39106 Magdeburg, Germany.
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15
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Koster F, Gouveia K, Zhou Y, Lowery K, Russell R, MacInnes H, Pollock Z, Layton RC, Cromwell J, Toleno D, Pyle J, Zubelewicz M, Harrod K, Sampath R, Hofstadler S, Gao P, Liu Y, Cheng YS. Exhaled aerosol transmission of pandemic and seasonal H1N1 influenza viruses in the ferret. PLoS One 2012; 7:e33118. [PMID: 22509254 PMCID: PMC3317934 DOI: 10.1371/journal.pone.0033118] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Accepted: 02/04/2012] [Indexed: 11/26/2022] Open
Abstract
Person-to-person transmission of influenza viruses occurs by contact (direct and fomites) and non-contact (droplet and small particle aerosol) routes, but the quantitative dynamics and relative contributions of these routes are incompletely understood. The transmissibility of influenza strains estimated from secondary attack rates in closed human populations is confounded by large variations in population susceptibilities. An experimental method to phenotype strains for transmissibility in an animal model could provide relative efficiencies of transmission. We developed an experimental method to detect exhaled viral aerosol transmission between unanesthetized infected and susceptible ferrets, measured aerosol particle size and number, and quantified the viral genomic RNA in the exhaled aerosol. During brief 3-hour exposures to exhaled viral aerosols in airflow-controlled chambers, three strains of pandemic 2009 H1N1 strains were frequently transmitted to susceptible ferrets. In contrast one seasonal H1N1 strain was not transmitted in spite of higher levels of viral RNA in the exhaled aerosol. Among three pandemic strains, the two strains causing weight loss and illness in the intranasally infected 'donor' ferrets were transmitted less efficiently from the donor than the strain causing no detectable illness, suggesting that the mucosal inflammatory response may attenuate viable exhaled virus. Although exhaled viral RNA remained constant, transmission efficiency diminished from day 1 to day 5 after donor infection. Thus, aerosol transmission between ferrets may be dependent on at least four characteristics of virus-host relationships including the level of exhaled virus, infectious particle size, mucosal inflammation, and viral replication efficiency in susceptible mucosa.
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Affiliation(s)
- Frederick Koster
- Program in Applied Science, Lovelace Respiratory Research Institute, Albuquerque, New Mexico, United States of America.
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16
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Ngunjiri JM, Lee CW, Ali A, Marcus PI. Influenza virus interferon-inducing particle efficiency is reversed in avian and mammalian cells, and enhanced in cells co-infected with defective-interfering particles. J Interferon Cytokine Res 2012; 32:280-5. [PMID: 22385205 DOI: 10.1089/jir.2011.0102] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Naturally selected variants of influenza virus encoding truncated NS1 proteins were tested in chickens as candidate live-attenuated influenza vaccines. Their effectiveness correlated with the amount of interferon (IFN) induced in chicken cells. Effective variants induced large amounts of IFN and contained subpopulations with high ratios of defective-interfering particles:IFN-inducing particles (DIP:IFP). Ineffective variants induced less IFN and contained lower ratios of DIP:IFP. Unexpectedly, there was a reversal of phenotypes in mammalian cells. Variants that induced low amounts of IFN and had low DIP:IFP ratios in chicken cells were excellent IFN inducers with high DIP:IFP ratios in mammalian cells, and vice versa. The high DIP:IFP ratios and computer-simulated dynamics of infection suggested that DIP, as an individual particle, did not function as an IFP. The higher efficiency of IFPs in the presence of DIPs was attributed to reduced amounts of newly synthesized viral polymerase known to result from out-competition by defective-interfering RNAs, and the subsequent failure of that polymerase to turn-off cellular mRNA transcription-including IFN-mRNA.
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Affiliation(s)
- John M Ngunjiri
- Virus and Interferon Research Laboratory, Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269, USA
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17
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Malinoski CP, Marcus PI. Influenza Virus: A Single Noninfectious Interferon Induction-Suppressing Particle Blocks Expression of Interferon-Inducing Particles. J Interferon Cytokine Res 2012; 32:121-6. [DOI: 10.1089/jir.2011.0078] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Christopher P. Malinoski
- Laboratory for Virus and Interferon Research, Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut
| | - Philip I. Marcus
- Laboratory for Virus and Interferon Research, Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut
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MacInnes H, Zhou Y, Gouveia K, Cromwell J, Lowery K, Layton RC, Zubelewicz M, Sampath R, Hofstadler S, Liu Y, Cheng YS, Koster F. Transmission of aerosolized seasonal H1N1 influenza A to ferrets. PLoS One 2011; 6:e24448. [PMID: 21949718 PMCID: PMC3176225 DOI: 10.1371/journal.pone.0024448] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 08/11/2011] [Indexed: 11/18/2022] Open
Abstract
Influenza virus is a major cause of morbidity and mortality worldwide, yet little quantitative understanding of transmission is available to guide evidence-based public health practice. Recent studies of influenza non-contact transmission between ferrets and guinea pigs have provided insights into the relative transmission efficiencies of pandemic and seasonal strains, but the infecting dose and subsequent contagion has not been quantified for most strains. In order to measure the aerosol infectious dose for 50% (aID50) of seronegative ferrets, seasonal influenza virus was nebulized into an exposure chamber with controlled airflow limiting inhalation to airborne particles less than 5 µm diameter. Airborne virus was collected by liquid impinger and Teflon filters during nebulization of varying doses of aerosolized virus. Since culturable virus was accurately captured on filters only up to 20 minutes, airborne viral RNA collected during 1-hour exposures was quantified by two assays, a high-throughput RT-PCR/mass spectrometry assay detecting 6 genome segments (Ibis T5000™ Biosensor system) and a standard real time RT-qPCR assay. Using the more sensitive T5000 assay, the aID50 for A/New Caledonia/20/99 (H1N1) was approximately 4 infectious virus particles under the exposure conditions used. Although seroconversion and sustained levels of viral RNA in upper airway secretions suggested established mucosal infection, viral cultures were almost always negative. Thus after inhalation, this seasonal H1N1 virus may replicate less efficiently than H3N2 virus after mucosal deposition and exhibit less contagion after aerosol exposure.
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Affiliation(s)
- Heather MacInnes
- Program in Infectious Disease, Lovelace Respiratory Research Institute, Albuquerque, New Mexico, United States of America
| | - Yue Zhou
- Program in Aerosol Science, Lovelace Respiratory Research Institute, Albuquerque, New Mexico, United States of America
| | - Kristine Gouveia
- Program in Infectious Disease, Lovelace Respiratory Research Institute, Albuquerque, New Mexico, United States of America
| | - Jenna Cromwell
- Ibis Biosciences, A Subsidiary of Abbott Molecular Inc., Carlsbad, California, United States of America
| | - Kristin Lowery
- Ibis Biosciences, A Subsidiary of Abbott Molecular Inc., Carlsbad, California, United States of America
| | - R. Colby Layton
- Program in Infectious Disease, Lovelace Respiratory Research Institute, Albuquerque, New Mexico, United States of America
| | - Michael Zubelewicz
- Program in Infectious Disease, Lovelace Respiratory Research Institute, Albuquerque, New Mexico, United States of America
| | - Rangarajan Sampath
- Ibis Biosciences, A Subsidiary of Abbott Molecular Inc., Carlsbad, California, United States of America
| | - Steven Hofstadler
- Ibis Biosciences, A Subsidiary of Abbott Molecular Inc., Carlsbad, California, United States of America
| | - Yushi Liu
- Program in Lung Cancer, Lovelace Respiratory Research Institute, Albuquerque, New Mexico, United States of America
| | - Yung-Sung Cheng
- Program in Aerosol Science, Lovelace Respiratory Research Institute, Albuquerque, New Mexico, United States of America
| | - Frederick Koster
- Program in Infectious Disease, Lovelace Respiratory Research Institute, Albuquerque, New Mexico, United States of America
- Program in Applied Science, Lovelace Respiratory Research Institute, Albuquerque, New Mexico, United States of America
- * E-mail:
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Hamilton SB, Wyatt DE, Wahlgren BT, O'Dowd MK, Morrissey JM, Daniels DE, Lednicky JA. Higher titers of some H5N1 and recent human H1N1 and H3N2 influenza viruses in Mv1 Lu vs. MDCK cells. Virol J 2011; 8:66. [PMID: 21314955 PMCID: PMC3046928 DOI: 10.1186/1743-422x-8-66] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Accepted: 02/11/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The infectivity of influenza A viruses can differ among the various primary cells and continuous cell lines used for such measurements. Over many years, we observed that all things equal, the cytopathic effects caused by influenza A subtype H1N1, H3N2, and H5N1 viruses were often detected earlier in a mink lung epithelial cell line (Mv1 Lu) than in MDCK cells. We asked whether virus yields as measured by the 50% tissue culture infectious dose and plaque forming titer also differed in MDCK and Mv1 Lu cells infected by the same influenza virus subtypes. RESULTS The 50% tissue culture infectious dose and plaque forming titer of many influenza A subtype H1N1, H3N2, and H5N1 viruses was higher in Mv1 Lu than in MDCK cells. CONCLUSIONS The yields of influenza subtype H1N1, H3N2, and H5N1 viruses can be higher in Mv1 Lu cells than in MDCK cells.
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Affiliation(s)
- Sara B Hamilton
- Energy and Life Sciences Division, Midwest Research Institute, 425 Volker Boulevard, Kansas City, Missouri 64110, USA
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Marcus PI, Ngunjiri JM, Sekellick MJ, Wang L, Lee CW. In vitro analysis of virus particle subpopulations in candidate live-attenuated influenza vaccines distinguishes effective from ineffective vaccines. J Virol 2010; 84:10974-81. [PMID: 20739541 PMCID: PMC2953188 DOI: 10.1128/jvi.00502-10] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Two effective (vac+) and two ineffective (vac-) candidate live-attenuated influenza vaccines (LAIVs) derived from naturally selected genetically stable variants of A/TK/OR/71-delNS1[1-124] (H7N3) that differed only in the length and kind of amino acid residues at the C terminus of the nonstructural NS1 protein were analyzed for their content of particle subpopulations. These subpopulations included total physical particles (measured as hemagglutinating particles [HAPs]) with their subsumed biologically active particles of infectious virus (plaque-forming particles [PFPs]) and different classes of noninfectious virus, namely, interferon-inducing particles (IFPs), noninfectious cell-killing particles (niCKPs), and defective interfering particles (DIPs). The vac+ variants were distinguished from the vac- variants on the basis of their content of viral subpopulations by (i) the capacity to induce higher quantum yields of interferon (IFN), (ii) the generation of an unusual type of IFN-induction dose-response curve, (iii) the presence of IFPs that induce IFN more efficiently, (iv) reduced sensitivity to IFN action, and (v) elevated rates of PFP replication that resulted in larger plaques and higher PFP and HAP titers. These in vitro analyses provide a benchmark for the screening of candidate LAIVs and their potential as effective vaccines. Vaccine design may be improved by enhancement of attributes that are dominant in the effective (vac+) vaccines.
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Affiliation(s)
- Philip I Marcus
- Department of Molecular and Cell Biology, Center of Excellence for Vaccine Research, University of Connecticut, U-3125, 91 North Eagleville Rd., Storrs, CT 06269, USA.
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Dynamics of biologically active subpopulations of influenza virus: plaque-forming, noninfectious cell-killing, and defective interfering particles. J Virol 2009; 83:8122-30. [PMID: 19494019 DOI: 10.1128/jvi.02680-08] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The dynamic changes in the temporal appearance and quantity of a new class of influenza virus, noninfectious cell-killing particles (niCKP), were compared to defective interfering particles (DIP). After a single high-multiplicity passage in MDCK cells of an egg-derived stock that lacked detectable niCKP or DIP, both classes of particles appeared in large numbers (>5 x 10(8)/ml), and the plaque-forming particle (PFP) titer dropped approximately 60-fold. After two additional serial high-multiplicity passages the DIP remained relatively constant, the DIP/niCKP ratio reached 10:1, and the PFP had declined by about 10,000-fold. Together, the niCKP and DIP subpopulations constituted ca. 20% of the total hemagglutinating particle population in which these noninfectious biologically active particles (niBAP) were subsumed. DIP neither killed cells nor interfered with the cell-killing (apoptosis-inducing) activity of niCKP or PFP (infectious CKP), even though they blocked the replication of PFP. Relative to the UV-target of approximately 13,600 nucleotides (nt) for inactivation of PFP, the UV target for niCKP was approximately 2,400 nt, consistent with one of the polymerase subunit genes, and that for DIP was approximately 350 nt, consistent with the small DI-RNA responsible for DIP-mediated interference. Thus, niCKP and DIP are viewed as distinct particles with a propensity to form during infection at high multiplicities. These conditions are postulated to cause aberrations in the temporally regulated replication of virus and its packaging, leading to the production of niBAP. DIP have been implicated in the virulence of influenza virus, but the role of niCKP is yet unknown.
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Infection dynamics and virus-induced apoptosis in cell culture-based influenza vaccine production—Flow cytometry and mathematical modeling. Vaccine 2009; 27:2712-22. [DOI: 10.1016/j.vaccine.2009.02.027] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Revised: 02/01/2009] [Accepted: 02/05/2009] [Indexed: 11/24/2022]
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