scholarly journals A live-cell imaging system for visualizing the transport of Marburg virus nucleocapsid-like structures

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Yuki Takamatsu ◽  
Olga Dolnik ◽  
Takeshi Noda ◽  
Stephan Becker
Keyword(s):  
Live Cell Imaging ◽  
Intracellular Transport ◽  
Actin Polymerization ◽  
Ebola Virus ◽  
Cell Imaging ◽  
Temporal Dynamics ◽  
Imaging System ◽  
Marburg Virus ◽  
Live Cell ◽  
Infected Cells

Abstract Background Live-cell imaging is a powerful tool for visualization of the spatio-temporal dynamics of moving signals in living cells. Although this technique can be utilized to visualize nucleocapsid transport in Marburg virus (MARV)- or Ebola virus-infected cells, the experiments require biosafety level-4 (BSL-4) laboratories, which are restricted to trained and authorized individuals. Methods To overcome this limitation, we developed a live-cell imaging system to visualize MARV nucleocapsid-like structures using fluorescence-conjugated viral proteins, which can be conducted outside BSL-4 laboratories. Results Our experiments revealed that nucleocapsid-like structures have similar transport characteristics to those of nucleocapsids observed in MARV-infected cells, both of which are mediated by actin polymerization. Conclusions We developed a non-infectious live cell imaging system to visualize intracellular transport of MARV nucleocapsid-like structures. This system provides a safe platform to evaluate antiviral drugs that inhibit MARV nucleocapsid transport.

scholarly journals A live-cell imaging system for visualizing the transport of Marburg virus nucleocapsid-like structures

2019 ◽  
Author(s):  
Yuki Takamatsu ◽  
Takeshi Noda ◽  
Stephan Becker
Keyword(s):  
Live Cell Imaging ◽  
Ebola Virus ◽  
Cell Imaging ◽  
Temporal Dynamics ◽  
Imaging System ◽  
Marburg Virus ◽  
Live Cell ◽  
Infected Cells ◽  
Spatio Temporal ◽  
Living Organisms

AbstractLive-cell imaging is a powerful tool for visualization of the spatio-temporal dynamics of living organisms. Although this technique is utilized to visualize nucleocapsid transport in Marburg virus (MARV)- or Ebola virus-infected cells, the experiments require biosafety level-4 (BSL-4) laboratories, which are restricted to trained and authorized individuals. To overcome this limitation, we developed a live-cell imaging system to visualize MARV nucleocapsid-like structures using fluorescence-conjugated viral proteins, which can be conducted outside BSL-4 laboratories. Our experiments revealed that nucleocapsid-like structures have similar transport characteristics to nucleocapsids observed in MARV-infected cells. This system provides a safe platform to evaluate antiviral drugs that inhibit MARV nucleocapsid transport.

scholarly journals Microtubule-dependent transport of arenavirus matrix protein demonstrated using live-cell imaging microscopy

Microscopy ◽  
2019 ◽  
Author(s):  
Yuki Takamatsu ◽  
Junichi Kajikawa ◽  
Yukiko Muramoto ◽  
Masahiro Nakano ◽  
Takeshi Noda
Keyword(s):  
Live Cell Imaging ◽  
Matrix Protein ◽  
Molecular Mechanisms ◽  
Cell Imaging ◽  
Imaging System ◽  
Live Cell ◽  
Matrix Proteins ◽  
Close Relative ◽  
Infected Cells ◽  
Z Protein

Abstract Lassa virus (LASV), belonging to the family Arenaviridae, causes severe haemorrhagic manifestations and is associated with a high mortality rate in humans. Thus, it is classified as a biosafety level (BSL)-4 agent. Since countermeasures for LASV diseases are yet to be developed, it is important to elucidate the molecular mechanisms underlying the life cycle of the virus, including its viral and host cellular protein interactions. These underlying molecular mechanisms may serve as the key for developing novel therapeutic options. Lymphocytic choriomeningitis virus (LCMV), a close relative of LASV, is usually asymptomatic and is categorized as a BSL-2 agent. In the present study, we visualized the transport of viral matrix Z protein in LCMV-infected cells using live-cell imaging microscopy. We demonstrated that the transport of Z protein is mediated by polymerized microtubules. Interestingly, the transport of LASV Z protein showed characteristics similar to those of Z protein in LCMV-infected cells. The live-cell imaging system using LCMV provides an attractive surrogate measure for studying arenavirus matrix protein transport in BSL-2 laboratories. In addition, it could be also utilized to analyze the interactions between viral matrix proteins and the cellular cytoskeleton, as well as to evaluate the antiviral compounds that target the transport of viral matrix proteins.

scholarly journals Transport of Ebolavirus Nucleocapsids Is Dependent on Actin Polymerization: Live-Cell Imaging Analysis of Ebolavirus-Infected Cells

2015 ◽  
Vol 212 (suppl 2) ◽  
pp. S160-S166 ◽  
Author(s):  
Gordian Schudt ◽  
Olga Dolnik ◽  
Larissa Kolesnikova ◽  
Nadine Biedenkopf ◽  
Astrid Herwig ◽  
...  
Keyword(s):  
Live Cell Imaging ◽  
Actin Polymerization ◽  
Cell Imaging ◽  
Live Cell ◽  
Imaging Analysis ◽  
Infected Cells

scholarly journals Microtubule-dependent transport of arenavirus matrix protein demonstrated using live-cell imaging microscopy

2019 ◽  
Author(s):  
Yuki Takamatsu ◽  
Junichi Kajikawa ◽  
Yukiko Muramoto ◽  
Masahiro Nakano ◽  
Takeshi Noda
Keyword(s):  
Live Cell Imaging ◽  
Matrix Protein ◽  
Molecular Mechanisms ◽  
Cell Imaging ◽  
Imaging System ◽  
Live Cell ◽  
Matrix Proteins ◽  
Close Relative ◽  
Infected Cells ◽  
Z Protein

AbstractLassa virus (LASV), belonging to the family Arenaviridae, causes severe haemorrhagic manifestations and is associated with a high mortality rate in humans. Thus, it is classified as a biosafety level (BSL)-4 agent. Since counter measures for LASV diseases are yet to be developed, it is important to elucidate the molecular mechanisms underlying the life cycle of the virus, including its viral and host cellular protein interactions. These underlying molecular mechanisms may serve as the key for developing novel therapeutic options. Lymphocytic choriomeningitis virus (LCMV), a close relative of LASV, is usually asymptomatic and is categorised as a BSL-2 agent. In the present study, we visualised the transport of viral matrix Z protein in LCMV-infected cells using live-cell imaging microscopy. We demonstrated that the transport of Z protein is mediated by polymerised microtubules. Interestingly, the transport of LASV Z protein showed characteristics similar to those of Z protein in LCMV-infected cells. The live-cell imaging system using LCMV provides an attractive surrogate measure for studying arenavirus matrix protein transport in BSL-2 laboratories. In addition, it could be also utilised to analyse the interactions between viral matrix proteins and the cellular cytoskeleton, as well as to evaluate the antiviral compounds that target the transport of viral matrix proteins.

scholarly journals A high-throughput screening assay based on automated microscopy for monitoring antibiotic susceptibility of Mycobacterium tuberculosis phenotypes

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sadaf Kalsum ◽  
Blanka Andersson ◽  
Jyotirmoy Das ◽  
Thomas Schön ◽  
Maria Lerm
Keyword(s):  
Mycobacterium Tuberculosis ◽  
High Throughput ◽  
High Throughput Screening ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Imaging System ◽  
Aggregate Size ◽  
Live Cell ◽  
Screening Assay ◽  
High Throughput Screening Assay

Abstract Background Efficient high-throughput drug screening assays are necessary to enable the discovery of new anti-mycobacterial drugs. The purpose of our work was to develop and validate an assay based on live-cell imaging which can monitor the growth of two distinct phenotypes of Mycobacterium tuberculosis and to test their susceptibility to commonly used TB drugs. Results Both planktonic and cording phenotypes were successfully monitored as fluorescent objects using the live-cell imaging system IncuCyte S3, allowing collection of data describing distinct characteristics of aggregate size and growth. The quantification of changes in total area of aggregates was used to define IC50 and MIC values of selected TB drugs which revealed that the cording phenotype grew more rapidly and displayed a higher susceptibility to rifampicin. In checkerboard approach, testing pair-wise combinations of sub-inhibitory concentrations of drugs, rifampicin, linezolid and pretomanid demonstrated superior growth inhibition of cording phenotype. Conclusions Our results emphasize the efficiency of using automated live-cell imaging and its potential in high-throughput whole-cell screening to evaluate existing and search for novel antimycobacterial drugs.

scholarly journals A versatile reporter system to monitor virus infected cells and its application to dengue virus and SARS-CoV-2

2020 ◽  
Author(s):  
Felix Pahmeier ◽  
Christoper J Neufeldt ◽  
Berati Cerikan ◽  
Vibhu Prasad ◽  
Costantin Pape ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Viral Replication ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Fluorescent Protein ◽  
Live Cell ◽  
Reporter System ◽  
Infected Cells ◽  
Positive Strand Rna

ABSTRACTPositive-strand RNA viruses have been the etiological agents in several major disease outbreaks over the last few decades. Examples of that are flaviviruses, such as dengue virus and Zika virus that cause millions of yearly infections and spread around the globe, and coronaviruses, such as SARS-CoV-2, which is the cause of the current pandemic. The severity of outbreaks caused by these viruses stresses the importance of virology research in determining mechanisms to limit virus spread and to curb disease severity. Such studies require molecular tools to decipher virus-host interactions and to develop effective interventions. Here, we describe the generation and characterization of a reporter system to visualize dengue virus and SARS-CoV-2 replication in live cells. The system is based on viral protease activity causing cleavage and nuclear translocation of an engineered fluorescent protein that is expressed in the infected cells. We show the suitability of the system for live cell imaging and visualization of single infected cells as well as for screening and testing of antiviral compounds. Given the modular building blocks, the system is easy to manipulate and can be adapted to any virus encoding a protease, thus offering a high degree of flexibility.IMPORTANCEReporter systems are useful tools for fast and quantitative visualization of viral replication and spread within a host cell population. Here we describe a reporter system that takes advantage of virus-encoded proteases that are expressed in infected cells to cleave an ER-anchored fluorescent protein fused to a nuclear localization sequence. Upon cleavage, the fluorescent protein translocates to the nucleus, allowing for rapid detection of the infected cells. Using this system, we demonstrate reliable reporting activity for two major human pathogens from the Flaviviridae and the Coronaviridae families: dengue virus and SARS-CoV-2. We apply this reporter system to live cell imaging and use it for proof-of-concept to validate antiviral activity of a nucleoside analogue. This reporter system is not only an invaluable tool for the characterization of viral replication, but also for the discovery and development of antivirals that are urgently needed to halt the spread of these viruses.

scholarly journals Ionomycin-induced calcium influx induces neurite degeneration in mouse neuroblastoma cells: analysis of a time-lapse live cell imaging system

2016 ◽  
Vol 50 (11) ◽  
pp. 1214-1225 ◽  
Author(s):  
Saki Nakamura ◽  
Ayumi Nakanishi ◽  
Minami Takazawa ◽  
Shunsuke Okihiro ◽  
Shiro Urano ◽  
...  
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Imaging System ◽  
Calcium Influx ◽  
Neuroblastoma Cells ◽  
Time Lapse ◽  
Live Cell ◽  
Mouse Neuroblastoma ◽  
Neurite Degeneration

scholarly journals Ebola Virus Nucleocapsid-Like Structures Utilize Arp2/3 Signaling for Intracellular Long-Distance Transport

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1728 ◽  
Author(s):  
Katharina Grikscheit ◽  
Olga Dolnik ◽  
Yuki Takamatsu ◽  
Ana Raquel Pereira ◽  
Stephan Becker
Keyword(s):  
Intracellular Transport ◽  
Actin Polymerization ◽  
Ebola Virus ◽  
Actin Dynamics ◽  
Long Distance ◽  
Long Distance Transport ◽  
Infected Cells ◽  
Resolution Imaging ◽  
Distance Transport ◽  
In Cells

The intracellular transport of nucleocapsids of the highly pathogenic Marburg, as well as Ebola virus (MARV, EBOV), represents a critical step during the viral life cycle. Intriguingly, a population of these nucleocapsids is distributed over long distances in a directed and polar fashion. Recently, it has been demonstrated that the intracellular transport of filoviral nucleocapsids depends on actin polymerization. While it was shown that EBOV requires Arp2/3-dependent actin dynamics, the details of how the virus exploits host actin signaling during intracellular transport are largely unknown. Here, we apply a minimalistic transfection system to follow the nucleocapsid-like structures (NCLS) in living cells, which can be used to robustly quantify NCLS transport in live cell imaging experiments. Furthermore, in cells co-expressing LifeAct, a marker for actin dynamics, NCLS transport is accompanied by pulsative actin tails appearing on the rear end of NCLS. These actin tails can also be preserved in fixed cells, and can be visualized via high resolution imaging using STORM in transfected, as well as EBOV infected, cells. The application of inhibitory drugs and siRNA depletion against actin regulators indicated that EBOV NCLS utilize the canonical Arp2/3-Wave1-Rac1 pathway for long-distance transport in cells. These findings highlight the relevance of the regulation of actin polymerization during directed EBOV nucleocapsid transport in human cells.

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