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Liu D, Pan L, Zhai H, Qiu HJ, Sun Y. Virus tracking technologies and their applications in viral life cycle: research advances and future perspectives. Front Immunol 2023; 14:1204730. [PMID: 37334362 PMCID: PMC10272434 DOI: 10.3389/fimmu.2023.1204730] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 05/22/2023] [Indexed: 06/20/2023] Open
Abstract
Viruses are simple yet highly pathogenic microorganisms that parasitize within cells and pose serious threats to the health, economic development, and social stability of both humans and animals. Therefore, it is crucial to understand the dynamic mechanism of virus infection in hosts. One effective way to achieve this is through virus tracking technology, which utilizes fluorescence imaging to track the life processes of virus particles in living cells in real-time, providing a comprehensively and detailed spatiotemporal dynamic process and mechanism of virus infection. This paper provides a broad overview of virus tracking technology, including the selection of fluorescent labels and virus labeling components, the development of imaging microscopes, and its applications in various virus studies. Additionally, we discuss the possibilities and challenges of its future development, offering theoretical guidance and technical support for effective prevention and control of the viral disease outbreaks and epidemics.
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Affiliation(s)
| | | | | | - Hua-Ji Qiu
- *Correspondence: Hua-Ji Qiu, ; Yuan Sun,
| | - Yuan Sun
- *Correspondence: Hua-Ji Qiu, ; Yuan Sun,
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2
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Scalisi S, Ahmad A, D'Annunzio S, Rousseau D, Zippo A. Quantitative Analysis of PcG-Associated Condensates by Stochastic Optical Reconstruction Microscopy (STORM). Methods Mol Biol 2023; 2655:183-200. [PMID: 37212997 DOI: 10.1007/978-1-0716-3143-0_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The polycomb group (PcG) proteins play a central role in the maintenance of a repressive state of gene expression. Recent findings demonstrate that PcG components are organized into nuclear condensates, contributing to the reshaping of chromatin architecture in physiological and pathological conditions, thus affecting the nuclear mechanics. In this context, direct stochastic optical reconstruction microscopy (dSTORM) provides an effective tool to achieve a detailed characterization of PcG condensates by visualizing them at a nanometric level. Furthermore, by analyzing dSTORM datasets with cluster analysis algorithms, quantitative information can be yielded regarding protein numbers, grouping, and spatial organization. Here, we describe how to set up a dSTORM experiment and perform the data analysis to study PcG complexes' components in adhesion cells quantitatively.
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Affiliation(s)
- Silvia Scalisi
- Chromatin Biology & Epigenetics Lab, Department of Cellular, Computational, and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Ali Ahmad
- Laboratoire Angevin de Recherche en Ingénierie des Systèmes, UMR INRAE IRHS, Université d'Angers, Angers, France
| | - Sarah D'Annunzio
- Chromatin Biology & Epigenetics Lab, Department of Cellular, Computational, and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - David Rousseau
- Laboratoire Angevin de Recherche en Ingénierie des Systèmes, UMR INRAE IRHS, Université d'Angers, Angers, France
| | - Alessio Zippo
- Chromatin Biology & Epigenetics Lab, Department of Cellular, Computational, and Integrative Biology (CIBIO), University of Trento, Trento, Italy.
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3
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Robb NC. Virus morphology: Insights from super-resolution fluorescence microscopy. Biochim Biophys Acta Mol Basis Dis 2022; 1868:166347. [PMID: 35032594 PMCID: PMC8755447 DOI: 10.1016/j.bbadis.2022.166347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 01/05/2022] [Accepted: 01/06/2022] [Indexed: 01/06/2023]
Abstract
As epitomised by the COVID-19 pandemic, diseases caused by viruses are one of the greatest health and economic burdens to human society. Viruses are ‘nanostructures’, and their small size (typically less than 200 nm in diameter) can make it challenging to obtain images of their morphology and structure. Recent advances in fluorescence microscopy have given rise to super-resolution techniques, which have enabled the structure of viruses to be visualised directly at a resolution in the order of 20 nm. This mini-review discusses how recent state-of-the-art super-resolution imaging technologies are providing new nanoscale insights into virus structure.
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Affiliation(s)
- Nicole C Robb
- Warwick Medical School, University of Warwick, Coventry CV4 7AL, United Kingdom.
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4
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Arista-Romero M, Pujals S, Albertazzi L. Towards a Quantitative Single Particle Characterization by Super Resolution Microscopy: From Virus Structures to Antivirals Design. Front Bioeng Biotechnol 2021; 9:647874. [PMID: 33842446 PMCID: PMC8033170 DOI: 10.3389/fbioe.2021.647874] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 03/08/2021] [Indexed: 12/15/2022] Open
Abstract
In the last year the COVID19 pandemic clearly illustrated the potential threat that viruses pose to our society. The characterization of viral structures and the identification of key proteins involved in each step of the cycle of infection are crucial to develop treatments. However, the small size of viruses, invisible under conventional fluorescence microscopy, make it difficult to study the organization of protein clusters within the viral particle. The applications of super-resolution microscopy have skyrocketed in the last years, converting this group into one of the leading techniques to characterize viruses and study the viral infection in cells, breaking the diffraction limit by achieving resolutions up to 10 nm using conventional probes such as fluorescent dyes and proteins. There are several super-resolution methods available and the selection of the right one it is crucial to study in detail all the steps involved in the viral infection, quantifying and creating models of infection for relevant viruses such as HIV-1, Influenza, herpesvirus or SARS-CoV-1. Here we review the use of super-resolution microscopy (SRM) to study all steps involved in the viral infection and antiviral design. In light of the threat of new viruses, these studies could inspire future assays to unveil the viral mechanism of emerging viruses and further develop successful antivirals against them.
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Affiliation(s)
- Maria Arista-Romero
- Nanoscopy for Nanomedicine Group, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Silvia Pujals
- Nanoscopy for Nanomedicine Group, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Department of Electronics and Biomedical Engineering, Faculty of Physics, Universitat de Barcelona, Barcelona, Spain
| | - Lorenzo Albertazzi
- Nanoscopy for Nanomedicine Group, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Department of Biomedical Engineering, Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Eindhoven, Netherlands
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Imaging Viral Infection by Fluorescence Microscopy: Focus on HIV-1 Early Stage. Viruses 2021; 13:v13020213. [PMID: 33573241 PMCID: PMC7911428 DOI: 10.3390/v13020213] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/28/2021] [Accepted: 01/28/2021] [Indexed: 12/15/2022] Open
Abstract
During the last two decades, progresses in bioimaging and the development of various strategies to fluorescently label the viral components opened a wide range of possibilities to visualize the early phase of Human Immunodeficiency Virus 1 (HIV-1) life cycle directly in infected cells. After fusion of the viral envelope with the cell membrane, the viral core is released into the cytoplasm and the viral RNA (vRNA) is retro-transcribed into DNA by the reverse transcriptase. During this process, the RNA-based viral complex transforms into a pre-integration complex (PIC), composed of the viral genomic DNA (vDNA) coated with viral and host cellular proteins. The protective capsid shell disassembles during a process called uncoating. The viral genome is transported into the cell nucleus and integrates into the host cell chromatin. Unlike biochemical approaches that provide global data about the whole population of viral particles, imaging techniques enable following individual viruses on a single particle level. In this context, quantitative microscopy has brought original data shedding light on the dynamics of the viral entry into the host cell, the cytoplasmic transport, the nuclear import, and the selection of the integration site. In parallel, multi-color imaging studies have elucidated the mechanism of action of host cell factors implicated in HIV-1 viral cycle progression. In this review, we describe the labeling strategies used for HIV-1 fluorescence imaging and report on the main advancements that imaging studies have brought in the understanding of the infection mechanisms from the viral entry into the host cell until the provirus integration step.
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Optical technologies for the detection of viruses like COVID-19: Progress and prospects. Biosens Bioelectron 2021; 178:113004. [PMID: 33497877 PMCID: PMC7832448 DOI: 10.1016/j.bios.2021.113004] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 02/07/2023]
Abstract
The outbreak of life-threatening pandemic like COVID-19 necessitated the development of novel, rapid and cost-effective techniques that facilitate detection of viruses like SARS-CoV-2. The presently popular approach of a collection of samples using the nasopharyngeal swab method and subsequent detection of RNA using the real-time polymerase chain reaction suffers from false-positive results and a longer diagnostic time scale. Alternatively, various optical techniques namely optical sensing, spectroscopy, and imaging shows a great promise in virus detection. Herein, a comprehensive review of the various photonics technologies employed for virus detection, particularly the SARS-CoV family, is discussed. The state-of-art research activities in utilizing the photonics tools such as near-infrared spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, fluorescence-based techniques, super-resolution microscopy, surface plasmon resonance-based detection, for virus detection accounted extensively with an emphasis on coronavirus detection. Further, an account of emerging photonics technologies of SARS-CoV-2 detection and future possibilities is also explained. The progress in the field of optical techniques for virus detection unambiguously show a great promise in the development of rapid photonics-based devices for COVID-19 detection.
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Groves NS, Bruns MM, van Engelenburg SB. A Quantitative Live-Cell Superresolution Imaging Framework for Measuring the Mobility of Single Molecules at Sites of Virus Assembly. Pathogens 2020; 9:pathogens9110972. [PMID: 33233482 PMCID: PMC7700196 DOI: 10.3390/pathogens9110972] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/13/2020] [Accepted: 11/18/2020] [Indexed: 12/11/2022] Open
Abstract
The insurgence of superresolution microscopy into the fields of virology and microbiology has begun to enable the mapping of molecular assemblies critical for host–pathogen interfaces that organize on a scale below the resolution limit of the light microscope. It is, however, challenging to completely understand the molecular interactions between host and pathogen from strictly time-invariant observations. Herein, we describe a method using simultaneous dual-color superresolution microscopy to gain both structural and dynamic information about HIV-1 assembly. Specifically, we demonstrate the reconstruction of single virus assembly sites using live-cell photo-activated localization microscopy (PALM) while concurrently assessing the sub-viral mobility of the HIV-1 envelope glycoprotein during interaction with the viral lattice. We propose that our method is broadly applicable to elucidating pathogen and host protein–protein interactions through quantification of the dynamics of these proteins at the nanoscale.
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Kiss B, Mudra D, Török G, Mártonfalvi Z, Csík G, Herényi L, Kellermayer M. Single-particle virology. Biophys Rev 2020; 12:1141-1154. [PMID: 32880826 PMCID: PMC7471434 DOI: 10.1007/s12551-020-00747-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 08/18/2020] [Indexed: 01/02/2023] Open
Abstract
The development of advanced experimental methodologies, such as optical tweezers, scanning-probe and super-resolved optical microscopies, has led to the evolution of single-molecule biophysics, a field of science that allows direct access to the mechanistic detail of biomolecular structure and function. The extension of single-molecule methods to the investigation of particles such as viruses permits unprecedented insights into the behavior of supramolecular assemblies. Here we address the scope of viral exploration at the level of individual particles. In an era of increased awareness towards virology, single-particle approaches are expected to facilitate the in-depth understanding, and hence combating, of viral diseases.
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Affiliation(s)
- Bálint Kiss
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Dorottya Mudra
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - György Török
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Zsolt Mártonfalvi
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Gabriella Csík
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Levente Herényi
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Miklós Kellermayer
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary.
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9
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Khater IM, Nabi IR, Hamarneh G. A Review of Super-Resolution Single-Molecule Localization Microscopy Cluster Analysis and Quantification Methods. PATTERNS (NEW YORK, N.Y.) 2020; 1:100038. [PMID: 33205106 PMCID: PMC7660399 DOI: 10.1016/j.patter.2020.100038] [Citation(s) in RCA: 122] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Single-molecule localization microscopy (SMLM) is a relatively new imaging modality, winning the 2014 Nobel Prize in Chemistry, and considered as one of the key super-resolution techniques. SMLM resolution goes beyond the diffraction limit of light microscopy and achieves resolution on the order of 10-20 nm. SMLM thus enables imaging single molecules and study of the low-level molecular interactions at the subcellular level. In contrast to standard microscopy imaging that produces 2D pixel or 3D voxel grid data, SMLM generates big data of 2D or 3D point clouds with millions of localizations and associated uncertainties. This unprecedented breakthrough in imaging helps researchers employ SMLM in many fields within biology and medicine, such as studying cancerous cells and cell-mediated immunity and accelerating drug discovery. However, SMLM data quantification and interpretation methods have yet to keep pace with the rapid advancement of SMLM imaging. Researchers have been actively exploring new computational methods for SMLM data analysis to extract biosignatures of various biological structures and functions. In this survey, we describe the state-of-the-art clustering methods adopted to analyze and quantify SMLM data and examine the capabilities and shortcomings of the surveyed methods. We classify the methods according to (1) the biological application (i.e., the imaged molecules/structures), (2) the data acquisition (such as imaging modality, dimension, resolution, and number of localizations), and (3) the analysis details (2D versus 3D, field of view versus region of interest, use of machine-learning and multi-scale analysis, biosignature extraction, etc.). We observe that the majority of methods that are based on second-order statistics are sensitive to noise and imaging artifacts, have not been applied to 3D data, do not leverage machine-learning formulations, and are not scalable for big-data analysis. Finally, we summarize state-of-the-art methodology, discuss some key open challenges, and identify future opportunities for better modeling and design of an integrated computational pipeline to address the key challenges.
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Affiliation(s)
- Ismail M. Khater
- Medical Image Analysis Lab, School of Computing Science, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Ivan Robert Nabi
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Ghassan Hamarneh
- Medical Image Analysis Lab, School of Computing Science, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
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10
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He Q, Yu D, Bao M, Korensky G, Chen J, Shin M, Kim J, Park M, Qin P, Du K. High-throughput and all-solution phase African Swine Fever Virus (ASFV) detection using CRISPR-Cas12a and fluorescence based point-of-care system. Biosens Bioelectron 2020; 154:112068. [DOI: 10.1016/j.bios.2020.112068] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/21/2019] [Accepted: 02/01/2020] [Indexed: 12/27/2022]
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11
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Khater IM, Meng F, Wong TH, Nabi IR, Hamarneh G. Super Resolution Network Analysis Defines the Molecular Architecture of Caveolae and Caveolin-1 Scaffolds. Sci Rep 2018; 8:9009. [PMID: 29899348 PMCID: PMC5998020 DOI: 10.1038/s41598-018-27216-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 05/24/2018] [Indexed: 12/04/2022] Open
Abstract
Quantitative approaches to analyze the large data sets generated by single molecule localization super-resolution microscopy (SMLM) are limited. We developed a computational pipeline and applied it to analyzing 3D point clouds of SMLM localizations (event lists) of the caveolar coat protein, caveolin-1 (Cav1), in prostate cancer cells differentially expressing CAVIN1 (also known as PTRF), that is also required for caveolae formation. High degree (strongly-interacting) points were removed by an iterative blink merging algorithm and Cav1 network properties were compared with randomly generated networks to retain a sub-network of geometric structures (or blobs). Machine-learning based classification extracted 28 quantitative features describing the size, shape, topology and network characteristics of ∼80,000 blobs. Unsupervised clustering identified small S1A scaffolds corresponding to SDS-resistant Cav1 oligomers, as yet undescribed larger hemi-spherical S2 scaffolds and, only in CAVIN1-expressing cells, spherical, hollow caveolae. Multi-threshold modularity analysis suggests that S1A scaffolds interact to form larger scaffolds and that S1A dimers group together, in the presence of CAVIN1, to form the caveolae coat.
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Affiliation(s)
- Ismail M Khater
- Medical Image Analysis Lab, School of Computing Science, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Fanrui Meng
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Timothy H Wong
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Ivan Robert Nabi
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
| | - Ghassan Hamarneh
- Medical Image Analysis Lab, School of Computing Science, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.
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12
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Chojnacki J, Eggeling C. Super-resolution fluorescence microscopy studies of human immunodeficiency virus. Retrovirology 2018; 15:41. [PMID: 29884197 PMCID: PMC5994058 DOI: 10.1186/s12977-018-0424-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 05/28/2018] [Indexed: 11/10/2022] Open
Abstract
Super-resolution fluorescence microscopy combines the ability to observe biological processes beyond the diffraction limit of conventional light microscopy with all advantages of the fluorescence readout such as labelling specificity and non-invasive live-cell imaging. Due to their subdiffraction size (< 200 nm) viruses are ideal candidates for super-resolution microscopy studies, and Human Immunodeficiency Virus type 1 (HIV-1) is to date the most studied virus by this technique. This review outlines principles of different super-resolution techniques as well as their advantages and disadvantages for virological studies, especially in the context of live-cell imaging applications. We highlight the findings of super-resolution based HIV-1 studies performed so far, their contributions to the understanding of HIV-1 replication cycle and how the current advances in super-resolution microscopy may open new avenues for future virology research.
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Affiliation(s)
- Jakub Chojnacki
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK.
| | - Christian Eggeling
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
- Institute of Applied Optics, Friedrich-Schiller-University Jena, Max-Wien Platz 4, 07743, Jena, Germany
- Leibniz Institute of Photonic Technology e.V., Albert-Einstein-Straße 9, 07745, Jena, Germany
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13
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Parveen N, Borrenberghs D, Rocha S, Hendrix J. Single Viruses on the Fluorescence Microscope: Imaging Molecular Mobility, Interactions and Structure Sheds New Light on Viral Replication. Viruses 2018; 10:E250. [PMID: 29748498 PMCID: PMC5977243 DOI: 10.3390/v10050250] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 04/24/2018] [Accepted: 05/04/2018] [Indexed: 12/13/2022] Open
Abstract
Viruses are simple agents exhibiting complex reproductive mechanisms. Decades of research have provided crucial basic insights, antiviral medication and moderately successful gene therapy trials. The most infectious viral particle is, however, not always the most abundant one in a population, questioning the utility of classic ensemble-averaging virology. Indeed, viral replication is often not particularly efficient, prone to errors or containing parallel routes. Here, we review different single-molecule sensitive fluorescence methods that we employ routinely to investigate viruses. We provide a brief overview of the microscopy hardware needed and discuss the different methods and their application. In particular, we review how we applied (i) single-molecule Förster resonance energy transfer (smFRET) to probe the subviral human immunodeficiency virus (HIV-1) integrase (IN) quaternary structure; (ii) single particle tracking to study interactions of the simian virus 40 with membranes; (iii) 3D confocal microscopy and smFRET to quantify the HIV-1 pre-integration complex content and quaternary structure; (iv) image correlation spectroscopy to quantify the cytosolic HIV-1 Gag assembly, and finally; (v) super-resolution microscopy to characterize the interaction of HIV-1 with tetherin during assembly. We hope this review is an incentive for setting up and applying similar single-virus imaging studies in daily virology practice.
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Affiliation(s)
- Nagma Parveen
- Laboratory for Photochemistry and Spectroscopy, Molecular Imaging and Photonics Division, Chemistry Department, KU Leuven, B-3001 Leuven, Belgium.
| | - Doortje Borrenberghs
- Laboratory for Photochemistry and Spectroscopy, Molecular Imaging and Photonics Division, Chemistry Department, KU Leuven, B-3001 Leuven, Belgium.
| | - Susana Rocha
- Laboratory for Photochemistry and Spectroscopy, Molecular Imaging and Photonics Division, Chemistry Department, KU Leuven, B-3001 Leuven, Belgium.
| | - Jelle Hendrix
- Laboratory for Photochemistry and Spectroscopy, Molecular Imaging and Photonics Division, Chemistry Department, KU Leuven, B-3001 Leuven, Belgium.
- Dynamic Bioimaging Lab, Advanced Optical Microscopy Centre and Biomedical Research Institute (BIOMED), Hasselt University, B-3590 Diepenbeek, Belgium.
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14
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Mohl BP, Roy P. Elucidating virus entry using a tetracysteine-tagged virus. Methods 2017; 127:23-29. [PMID: 28802715 DOI: 10.1016/j.ymeth.2017.08.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 07/20/2017] [Accepted: 08/05/2017] [Indexed: 01/30/2023] Open
Abstract
Fluorescent tags constitute an invaluable tool in facilitating a deeper understanding of the mechanistic processes governing virus-host interactions. However, when selecting a fluorescent tag for in vivo imaging of cells, a number of parameters and aspects must be considered. These include whether the tag may affect and interfere with protein conformation or localization, cell toxicity, spectral overlap, photo-stability and background. Cumulatively, these constitute challenges to be overcome. Bluetongue virus (BTV), a member of the Orbivirus genus in the Reoviridae family, is a non-enveloped virus that is comprised of two architecturally complex capsids. The outer capsid, composed of two proteins, VP2 and VP5, together facilitate BTV attachment, entry and the delivery of the transcriptionally active core in the cell cytoplasm. Previously, the significance of the endocytic pathway for BTV entry was reported, although a detailed analysis of the role of each protein during virus trafficking remained elusive due to the unavailability of a tagged virus. Described here is the successful modification, and validation, of a segmented genome belonging to a complex and large capsid virus to introduce tags for fluorescence visualization. The data generated from this approach highlighted the sequential dissociation of VP2 and VP5, driven by decreasing pH during the transition from early to late endosomes, and their retention therein as the virus particles progress along the endocytic pathway. Furthermore, the described tagging technology and methodology may prove transferable and allow for the labeling of other non-enveloped complex viruses.
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Affiliation(s)
- Bjorn-Patrick Mohl
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Polly Roy
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
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15
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Nicovich PR, Owen DM, Gaus K. Turning single-molecule localization microscopy into a quantitative bioanalytical tool. Nat Protoc 2017; 12:453-460. [DOI: 10.1038/nprot.2016.166] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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16
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Superresolution Imaging of Clinical Formalin Fixed Paraffin Embedded Breast Cancer with Single Molecule Localization Microscopy. Sci Rep 2017; 7:40766. [PMID: 28098202 PMCID: PMC5241681 DOI: 10.1038/srep40766] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 12/12/2016] [Indexed: 11/19/2022] Open
Abstract
Millions of archived formalin-fixed, paraffin-embedded (FFPE) specimens contain valuable molecular insight into healthy and diseased states persevered in their native ultrastructure. To diagnose and treat diseases in tissue on the nanoscopic scale, pathology traditionally employs electron microscopy (EM), but this platform has significant limitations including cost and painstaking sample preparation. The invention of single molecule localization microscopy (SMLM) optically overcame the diffraction limit of light to resolve fluorescently labeled molecules on the nanoscale, leading to many exciting biological discoveries. However, applications of SMLM in preserved tissues has been limited. Through adaptation of the immunofluorescence workflow on FFPE sections milled at histological thickness, cellular architecture can now be visualized on the nanoscale using SMLM including individual mitochondria, undulations in the nuclear lamina, and the HER2 receptor on membrane protrusions in human breast cancer specimens. Using astigmatism imaging, these structures can also be resolved in three dimensions to a depth of ~800 nm. These results demonstrate the utility of SMLM in efficiently uncovering ultrastructural information of archived clinical samples, which may offer molecular insights into the physiopathology of tissues to assist in disease diagnosis and treatment using conventional sample preparation methods.
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Hanne J, Zila V, Heilemann M, Müller B, Kräusslich HG. Super-resolved insights into human immunodeficiency virus biology. FEBS Lett 2016; 590:1858-76. [PMID: 27117435 DOI: 10.1002/1873-3468.12186] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 04/13/2016] [Accepted: 04/21/2016] [Indexed: 11/06/2022]
Abstract
The recent development of fluorescence microscopy approaches overcoming the diffraction limit of light microscopy opened possibilities for studying small-scale cellular processes. The spatial resolution achieved by these novel techniques, together with the possibility to perform live-cell and multicolor imaging, make them ideally suited for visualization of native viruses and subviral structures within the complex environment of a host cell or organ, thus providing fundamentally new possibilities for investigating virus-cell interactions. Here, we review the use of super-resolution microscopy approaches to study virus-cell interactions, and discuss recent insights into human immunodeficiency virus biology obtained by exploiting these novel techniques.
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Affiliation(s)
- Janina Hanne
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Germany.,Optical Nanoscopy Division, German Cancer Research Center, Heidelberg, Germany
| | - Vojtech Zila
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Germany
| | - Mike Heilemann
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Germany
| | - Barbara Müller
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Germany
| | - Hans-Georg Kräusslich
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Germany
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18
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Florian PE, Rouillé Y, Ruta S, Nichita N, Roseanu A. Recent advances in human viruses imaging studies. J Basic Microbiol 2016; 56:591-607. [DOI: 10.1002/jobm.201500575] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 02/27/2016] [Indexed: 12/13/2022]
Affiliation(s)
- Paula Ecaterina Florian
- Department of ; Ligand-Receptor Interactions; Institute of Biochemistry of the Romanian Academy; Bucharest Romania
| | - Yves Rouillé
- Center for Infection and Immunity of Lille (CIIL); Inserm U1019; CNRS UMR8204; Institut Pasteur de Lille; Université Lille Nord de France; Lille France
| | - Simona Ruta
- Department of Emergent Diseases; Stefan S. Nicolau Institute of Virology; Bucharest 030304 Romania
| | - Norica Nichita
- Department of Viral Glycoproteins; Institute of Biochemistry of the Romanian Academy; Bucharest Romania
| | - Anca Roseanu
- Department of ; Ligand-Receptor Interactions; Institute of Biochemistry of the Romanian Academy; Bucharest Romania
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19
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Sydor AM, Czymmek KJ, Puchner EM, Mennella V. Super-Resolution Microscopy: From Single Molecules to Supramolecular Assemblies. Trends Cell Biol 2015; 25:730-748. [DOI: 10.1016/j.tcb.2015.10.004] [Citation(s) in RCA: 185] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 10/03/2015] [Accepted: 10/05/2015] [Indexed: 11/25/2022]
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20
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Desai TM, Marin M, Sood C, Shi J, Nawaz F, Aiken C, Melikyan GB. Fluorescent protein-tagged Vpr dissociates from HIV-1 core after viral fusion and rapidly enters the cell nucleus. Retrovirology 2015; 12:88. [PMID: 26511606 PMCID: PMC4625717 DOI: 10.1186/s12977-015-0215-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 10/16/2015] [Indexed: 02/06/2023] Open
Abstract
Background HIV-1 Vpr is recruited into virions during assembly and appears to remain associated with the viral core after the reverse transcription and uncoating steps of entry. This feature has prompted the use of fluorescently labeled Vpr to visualize viral particles and to follow trafficking of post-fusion HIV-1 cores in the cytoplasm. Results Here, we tracked single pseudovirus entry and fusion and observed that fluorescently tagged Vpr gradually dissociates from post-fusion viral cores over the course of several minutes and accumulates in the nucleus. Kinetics measurements showed that fluorescent Vpr released from the cores very rapidly entered the cell nucleus. More than 10,000 Vpr molecules can be delivered into the cell nucleus within 45 min of infection by HIV-1 particles pseudotyped with the avian sarcoma and leukosis virus envelope glycoprotein. The fraction of Vpr from cell-bound viruses that accumulated in the nucleus was proportional to the extent of virus-cell fusion and was fully blocked by viral fusion inhibitors. Entry of virus-derived Vpr into the nucleus occurred independently of envelope glycoproteins or target cells. Fluorescence correlation spectroscopy revealed two forms of nuclear Vpr—monomers and very large complexes, likely involving host factors. The kinetics of viral Vpr entering the nucleus after fusion was not affected by point mutations in the capsid protein that alter the stability of the viral core. Conclusions The independence of Vpr shedding of capsid stability and its relatively rapid dissociation from post-fusion cores suggest that this process may precede capsid uncoating, which appears to occur on a slower time scale. Our results thus demonstrate that a bulk of fluorescently labeled Vpr incorporated into HIV-1 particles is released shortly after fusion. Future studies will address the question whether the quick and efficient nuclear delivery of Vpr derived from incoming viruses can regulate subsequent steps of HIV-1 infection. Electronic supplementary material The online version of this article (doi:10.1186/s12977-015-0215-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Tanay M Desai
- Division of Pediatric Infectious Diseases, Emory University School of Medicine, Atlanta, GA, USA.
| | - Mariana Marin
- Division of Pediatric Infectious Diseases, Emory University School of Medicine, Atlanta, GA, USA.
| | - Chetan Sood
- Division of Pediatric Infectious Diseases, Emory University School of Medicine, Atlanta, GA, USA.
| | - Jiong Shi
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, TN, 37232, USA.
| | - Fatima Nawaz
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, TN, 37232, USA.
| | - Christopher Aiken
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, TN, 37232, USA.
| | - Gregory B Melikyan
- Division of Pediatric Infectious Diseases, Emory University School of Medicine, Atlanta, GA, USA. .,Children's Healthcare of Atlanta, Atlanta, GA, USA.
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21
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Pham S, Tabarin T, Garvey M, Pade C, Rossy J, Monaghan P, Hyatt A, Böcking T, Leis A, Gaus K, Mak J. Cryo-electron microscopy and single molecule fluorescent microscopy detect CD4 receptor induced HIV size expansion prior to cell entry. Virology 2015; 486:121-33. [PMID: 26432024 DOI: 10.1016/j.virol.2015.09.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 09/09/2015] [Accepted: 09/10/2015] [Indexed: 10/23/2022]
Abstract
Viruses are often thought to have static structure, and they only remodel after the viruses have entered target cells. Here, we detected a size expansion of virus particles prior to viral entry using cryo-electron microscopy (cryo-EM) and single molecule fluorescence imaging. HIV expanded both under cell-free conditions with soluble receptor CD4 (sCD4) targeting the CD4 binding site on the HIV-1 envelope protein (Env) and when HIV binds to receptor on cellular membrane. We have shown that the HIV Env is needed to facilitate receptor induced virus size expansions, showing that the 'lynchpin' for size expansion is highly specific. We demonstrate that the size expansion required maturation of HIV and an internal capsid core with wild type stability, suggesting that different HIV compartments are linked and are involved in remodelling. Our work reveals a previously unknown event in HIV entry, and we propose that this pre-entry priming process enables HIV particles to facilitate the subsequent steps in infection.
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Affiliation(s)
- Son Pham
- Deakin University, Victoria 3216, Australia; CSIRO Australian Animal Health Laboratory, Victoria 3220, Australia
| | - Thibault Tabarin
- ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, New South Wales 3220, Australia
| | - Megan Garvey
- Deakin University, Victoria 3216, Australia; CSIRO Australian Animal Health Laboratory, Victoria 3220, Australia
| | - Corinna Pade
- Deakin University, Victoria 3216, Australia; CSIRO Australian Animal Health Laboratory, Victoria 3220, Australia
| | - Jérémie Rossy
- ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, New South Wales 3220, Australia
| | - Paul Monaghan
- CSIRO Australian Animal Health Laboratory, Victoria 3220, Australia
| | - Alex Hyatt
- CSIRO Australian Animal Health Laboratory, Victoria 3220, Australia
| | - Till Böcking
- ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, New South Wales 3220, Australia
| | - Andrew Leis
- CSIRO Australian Animal Health Laboratory, Victoria 3220, Australia
| | - Katharina Gaus
- ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, New South Wales 3220, Australia.
| | - Johnson Mak
- Deakin University, Victoria 3216, Australia; CSIRO Australian Animal Health Laboratory, Victoria 3220, Australia.
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22
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Mengistu M, Ray K, Lewis GK, DeVico AL. Antigenic properties of the human immunodeficiency virus envelope glycoprotein gp120 on virions bound to target cells. PLoS Pathog 2015; 11:e1004772. [PMID: 25807494 PMCID: PMC4373872 DOI: 10.1371/journal.ppat.1004772] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 03/02/2015] [Indexed: 12/17/2022] Open
Abstract
The HIV-1 envelope glycoprotein, gp120, undergoes multiple molecular interactions and structural rearrangements during the course of host cell attachment and viral entry, which are being increasingly defined at the atomic level using isolated proteins. In comparison, antigenic markers of these dynamic changes are essentially unknown for single HIV-1 particles bound to target cells. Such markers should indicate how neutralizing and/or non-neutralizing antibodies might interdict infection by either blocking infection or sensitizing host cells for elimination by Fc-mediated effector function. Here we address this deficit by imaging fluorescently labeled CCR5-tropic HIV-1 pseudoviruses using confocal and superresolution microscopy to track the exposure of neutralizing and non-neutralizing epitopes as they appear on single HIV-1 particles bound to target cells. Epitope exposure was followed under conditions permissive or non-permissive for viral entry to delimit changes associated with virion binding from those associated with post-attachment events. We find that a previously unexpected array of gp120 epitopes is exposed rapidly upon target cell binding. This array comprises both neutralizing and non-neutralizing epitopes, the latter being hidden on free virions yet capable of serving as potent targets for Fc-mediated effector function. Under non-permissive conditions for viral entry, both neutralizing and non-neutralizing epitope exposures were relatively static over time for the majority of bound virions. Under entry-permissive conditions, epitope exposure patterns changed over time on subsets of virions that exhibited concurrent variations in virion contents. These studies reveal that bound virions are distinguished by a broad array of both neutralizing and non-neutralizing gp120 epitopes that potentially sensitize a freshly engaged target cell for destruction by Fc-mediated effector function and/or for direct neutralization at a post-binding step. The elucidation of these epitope exposure patterns during viral entry will help clarify antibody-mediated inhibition of HIV-1 as it is measured in vitro and in vivo. A major strategy for blocking HIV-1 infection is to target antiviral antibodies or drugs to sites of vulnerability on the surface proteins of the virus. It is a relatively straightforward matter to explore these sites on the surfaces of free HIV-1 particles or on isolated viral envelope antigens. However, one difficulty presented by HIV-1 is that its surface proteins are flexible and change shape once the virus has attached to its host cell. To date, it has been difficult to predict how cell-bound HIV-1 exposes its sites of vulnerability. Yet the antiviral activities of certain antibodies indirectly suggest that there must be unique sites on cell-bound HIV-1 that are not found on free virus. Here, we use new techniques and tools to determine how HIV-1 exposes unique sites of vulnerability after attaching to host cells. We find that the virus exposes a remarkable array of these sites, including ones previously believed hidden. These exposure patterns explain the antiviral activities of various anti-HIV-1 antibodies and provide a new view of how HIV-1 might interact with the immune system. Our study also provides insights for how to target HIV-1 with antiviral antibodies, vaccines, or antiviral agents.
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Affiliation(s)
- Meron Mengistu
- The Institute of Human Virology of the University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (MM); (ALD)
| | - Krishanu Ray
- Center for Fluorescence Spectroscopy of the University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - George K. Lewis
- The Institute of Human Virology of the University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Anthony L. DeVico
- The Institute of Human Virology of the University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (MM); (ALD)
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23
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Superresolution imaging of viral protein trafficking. Med Microbiol Immunol 2015; 204:449-60. [PMID: 25724304 DOI: 10.1007/s00430-015-0395-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 02/13/2015] [Indexed: 12/25/2022]
Abstract
The endoplasmic reticulum (ER) membrane is closely apposed to the outer mitochondrial membrane (OMM), which facilitates communication between these organelles. These contacts, known as mitochondria-associated membranes (MAM), facilitate calcium signaling, lipid transfer, as well as antiviral and stress responses. How cellular proteins traffic to the MAM, are distributed therein, and interact with ER and mitochondrial proteins are subject of great interest. The human cytomegalovirus UL37 exon 1 protein or viral mitochondria-localized inhibitor of apoptosis (vMIA) is crucial for viral growth. Upon synthesis at the ER, vMIA traffics to the MAM and OMM, where it reprograms the organization and function of these compartments. vMIA significantly changes the abundance of cellular proteins at the MAM and OMM, including proteins that regulate calcium homeostasis and cell death. Through the use of superresolution imaging, we have shown that vMIA is distributed at the OMM in nanometer scale clusters. This is similar to the clusters reported for the mitochondrial calcium channel, VDAC, as well as electron transport chain, translocase of the OMM complex, and mitochondrial inner membrane organizing system components. Thus, aside from addressing how vMIA targets the MAM and regulates survival of infected cells, biochemical studies and superresolution imaging of vMIA offer insights into the formation, organization, and functioning of MAM. Here, we discuss these insights into trafficking, function, and organization of vMIA at the MAM and OMM and discuss how the use of superresolution imaging is contributing to the study of the formation and trafficking of viruses.
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24
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Latinovic O, Schneider K, Szmacinski H, Lakowicz JR, Heredia A, Redfield RR. Binding of fusion protein FLSC IgG1 to CCR5 is enhanced by CCR5 antagonist Maraviroc. Antiviral Res 2014; 112:80-90. [PMID: 25453341 DOI: 10.1016/j.antiviral.2014.10.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/03/2014] [Accepted: 10/10/2014] [Indexed: 11/30/2022]
Abstract
The CCR5 chemokine receptor is crucial for human immunodeficiency virus type 1 (HIV-1) infection, acting as the principal coreceptor for HIV-1 entry and transmission and is thus an attractive target for antiviral therapy. Studies have suggested that CCR5 surface density and its conformational changes subsequent to virion engagement are rate limiting for entry, and consequently, infection. Not all CCR5 antibodies inhibit HIV-1 infection, suggesting a need for more potent reagents. Here we evaluated full length single chain (FLSC) IgG1, a novel IgG-CD4-gp120(BAL) fusion protein with several characteristics that make it an attractive candidate for treatment of HIV-1 infections, including bivalency and a potentially increased serum half-life over FLSC, the parental molecule. FLSC IgG1 binds two domains on CCR5, the N-terminus and the second extracellular loop, lowering the levels of available CCR5 viral attachment sites. Furthermore, FLSC IgG1 synergizes with Maraviroc (MVC), the only licensed CCR5 antagonist. In this study, we used both microscopy and functional assays to address the mechanistic aspects of the interactions of FLSC IgG1 and MVC in the context of CCR5 conformational changes and viral infection. We used a novel stochastic optical reconstruction microscopy (STORM), based on high resolution localization of photoswitchable dyes to visualize direct contacts between FLSC IgG1 and CCR5. We compared viral entry inhibition by FLSC IgG1 with that of other CCR5 blockers and showed FLSC IgG1 to be the most potent. We also showed that lower CCR5 surface densities in HIV-1 infected primary cells result in lower FLSC IgG1 EC50 values. In addition, CCR5 binding by FLSC IgG1, but not CCR5 Ab 2D7, was significantly increased when cells were treated with MVC, suggesting MVC allosterically increases exposure of the FLSC IgG1 binding site. These data have implications for future antiviral therapy development.
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Affiliation(s)
- Olga Latinovic
- Institute of Human Virology, University of Maryland, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kate Schneider
- Institute of Human Virology, University of Maryland, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Henryk Szmacinski
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Joseph R Lakowicz
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Alonso Heredia
- Institute of Human Virology, University of Maryland, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Robert R Redfield
- Institute of Human Virology, University of Maryland, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
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25
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Eggert D, Rösch K, Reimer R, Herker E. Visualization and analysis of hepatitis C virus structural proteins at lipid droplets by super-resolution microscopy. PLoS One 2014; 9:e102511. [PMID: 25019511 PMCID: PMC4094509 DOI: 10.1371/journal.pone.0102511] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 06/19/2014] [Indexed: 12/17/2022] Open
Abstract
Cytosolic lipid droplets are central organelles in the Hepatitis C Virus (HCV) life cycle. The viral capsid protein core localizes to lipid droplets and initiates the production of viral particles at lipid droplet–associated ER membranes. Core is thought to encapsidate newly synthesized viral RNA and, through interaction with the two envelope proteins E1 and E2, bud into the ER lumen. Here, we visualized the spatial distribution of HCV structural proteins core and E2 in vicinity of small lipid droplets by three-color 3D super-resolution microscopy. We observed and analyzed small areas of colocalization between the two structural proteins in HCV-infected cells with a diameter of approximately 100 nm that might represent putative viral assembly sites.
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Affiliation(s)
- Dennis Eggert
- Heinrich-Pette-Institute, Leibniz Institute for Experimental Virology, University of Hamburg, Hamburg, Germany
- Institute of Physical Chemistry, University of Hamburg, Hamburg, Germany
| | - Kathrin Rösch
- Heinrich-Pette-Institute, Leibniz Institute for Experimental Virology, University of Hamburg, Hamburg, Germany
| | - Rudolph Reimer
- Heinrich-Pette-Institute, Leibniz Institute for Experimental Virology, University of Hamburg, Hamburg, Germany
| | - Eva Herker
- Heinrich-Pette-Institute, Leibniz Institute for Experimental Virology, University of Hamburg, Hamburg, Germany
- * E-mail:
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26
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Shivanandan A, Deschout H, Scarselli M, Radenovic A. Challenges in quantitative single molecule localization microscopy. FEBS Lett 2014; 588:3595-602. [PMID: 24928440 DOI: 10.1016/j.febslet.2014.06.014] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 06/01/2014] [Accepted: 06/02/2014] [Indexed: 11/18/2022]
Abstract
Single molecule localization microscopy (SMLM), which can provide up to an order of magnitude improvement in spatial resolution over conventional fluorescence microscopy, has the potential to be a highly useful tool for quantitative biological experiments. It has already been used for this purpose in varied fields in biology, ranging from molecular biology to neuroscience. In this review article, we briefly review the applications of SMLM in quantitative biology, and also the challenges involved and some of the solutions that have been proposed. Due to its advantages in labeling specificity and the relatively low overcounting caused by photoblinking when photo-activable fluorescent proteins (PA-FPs) are used as labels, we focus specifically on Photo-Activated Localization Microscopy (PALM), even though the ideas presented might be applicable to SMLM in general. Also, we focus on the following three quantitative measurements: single molecule counting, analysis of protein spatial distribution heterogeneity and co-localization analysis.
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Affiliation(s)
- A Shivanandan
- Laboratory of Nanoscale Biology, Institute of Bioengineering, School of Engineering, EPFL, Lausanne, Switzerland
| | - H Deschout
- Laboratory of Nanoscale Biology, Institute of Bioengineering, School of Engineering, EPFL, Lausanne, Switzerland
| | - M Scarselli
- Laboratory of Nanoscale Biology, Institute of Bioengineering, School of Engineering, EPFL, Lausanne, Switzerland
| | - A Radenovic
- Laboratory of Nanoscale Biology, Institute of Bioengineering, School of Engineering, EPFL, Lausanne, Switzerland.
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27
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Borrenberghs D, Thys W, Rocha S, Demeulemeester J, Weydert C, Dedecker P, Hofkens J, Debyser Z, Hendrix J. HIV virions as nanoscopic test tubes for probing oligomerization of the integrase enzyme. ACS NANO 2014; 8:3531-45. [PMID: 24654558 PMCID: PMC4004294 DOI: 10.1021/nn406615v] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Employing viruses as nanoscopic lipid-enveloped test tubes allows the miniaturization of protein-protein interaction (PPI) assays while preserving the physiological environment necessary for particular biological processes. Applied to the study of the human immunodeficiency virus type 1 (HIV-1), viral biology and pathology can also be investigated in novel ways, both in vitro as well as in infected cells. In this work we report on an experimental strategy that makes use of engineered HIV-1 viral particles, to allow for probing PPIs of the HIV-1 integrase (IN) inside viruses with single-molecule Förster resonance energy transfer (FRET) using fluorescent proteins (FP). We show that infectious fluorescently labeled viruses can be obtained and that the quantity of labels can be accurately measured and controlled inside individual viral particles. We demonstrate, with proper control experiments, the formation of IN oligomers in single viral particles and inside viral complexes in infected cells. Finally, we show a clear effect on IN oligomerization of small molecule inhibitors of interactions of IN with its natural human cofactor LEDGF/p75, corroborating that IN oligomer enhancing drugs are active already at the level of the virus and strongly suggesting the presence of a dynamic, enhanceable equilibrium between the IN dimer and tetramer in viral particles. Although applied to the HIV-1 IN enzyme, our methodology for utilizing HIV virions as nanoscopic test tubes for probing PPIs is generic, i.e., other PPIs targeted into the HIV-1, or PPIs targeted into other viruses, can potentially be studied with a similar strategy.
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Affiliation(s)
- Doortje Borrenberghs
- Laboratory for Photochemistry and Spectroscopy, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001 Heverlee, Flanders, Belgium
| | - Wannes Thys
- Laboratory for Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Kapucijnenvoer 33, 3000 Leuven, Flanders, Belgium
| | - Susana Rocha
- Laboratory for Photochemistry and Spectroscopy, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001 Heverlee, Flanders, Belgium
| | - Jonas Demeulemeester
- Laboratory for Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Kapucijnenvoer 33, 3000 Leuven, Flanders, Belgium
| | - Caroline Weydert
- Laboratory for Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Kapucijnenvoer 33, 3000 Leuven, Flanders, Belgium
| | - Peter Dedecker
- Laboratory for Photochemistry and Spectroscopy, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001 Heverlee, Flanders, Belgium
| | - Johan Hofkens
- Laboratory for Photochemistry and Spectroscopy, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001 Heverlee, Flanders, Belgium
- Nano-Science Center, Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Zeger Debyser
- Laboratory for Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Kapucijnenvoer 33, 3000 Leuven, Flanders, Belgium
| | - Jelle Hendrix
- Laboratory for Photochemistry and Spectroscopy, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001 Heverlee, Flanders, Belgium
- Address correspondence to
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Grove J. Super-resolution microscopy: a virus' eye view of the cell. Viruses 2014; 6:1365-78. [PMID: 24651030 PMCID: PMC3970155 DOI: 10.3390/v6031365] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 03/01/2014] [Accepted: 03/11/2014] [Indexed: 12/24/2022] Open
Abstract
It is difficult to observe the molecular choreography between viruses and host cell components, as they exist on a spatial scale beyond the reach of conventional microscopy. However, novel super-resolution microscopy techniques have cast aside technical limitations to reveal a nanoscale view of virus replication and cell biology. This article provides an introduction to super-resolution imaging; in particular, localisation microscopy, and explores the application of such technologies to the study of viruses and tetraspanins, the topic of this special issue.
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Affiliation(s)
- Joe Grove
- Institute of Immunity and Transplantation, University College London, London NW3 2PF, UK.
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29
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Tabarin T, Pageon SV, Bach CTT, Lu Y, O'Neill GM, Gooding JJ, Gaus K. Insights into Adhesion Biology Using Single-Molecule Localization Microscopy. Chemphyschem 2014; 15:606-18. [DOI: 10.1002/cphc.201301041] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Indexed: 01/07/2023]
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30
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Huang LL, Xie HY. Progress on the labeling and single-particle tracking technologies of viruses. Analyst 2014; 139:3336-46. [DOI: 10.1039/c4an00038b] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We review recent advances in virus labeling and the emerging fluorescence imaging technologies used in the imaging and tracking of viruses.
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Affiliation(s)
- Li-Li Huang
- School of Life Science
- Beijing Institute of Technology
- Beijing 100081, China
| | - Hai-Yan Xie
- School of Life Science
- Beijing Institute of Technology
- Beijing 100081, China
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31
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Han R, Li Z, Fan Y, Jiang Y. Recent Advances in Super-Resolution Fluorescence Imaging and Its Applications in Biology. J Genet Genomics 2013; 40:583-95. [DOI: 10.1016/j.jgg.2013.11.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 11/11/2013] [Accepted: 11/11/2013] [Indexed: 11/16/2022]
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32
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Viral and cellular requirements for the nuclear entry of retroviral preintegration nucleoprotein complexes. Viruses 2013; 5:2483-511. [PMID: 24103892 PMCID: PMC3814599 DOI: 10.3390/v5102483] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 09/26/2013] [Accepted: 10/03/2013] [Indexed: 02/07/2023] Open
Abstract
Retroviruses integrate their reverse transcribed genomes into host cell chromosomes as an obligate step in virus replication. The nuclear envelope separates the chromosomes from the cell cytoplasm during interphase, and different retroviral groups deal with this physical barrier in different ways. Gammaretroviruses are dependent on the passage of target cells through mitosis, where they are believed to access chromosomes when the nuclear envelope dissolves for cell division. Contrastingly, lentiviruses such as HIV-1 infect non-dividing cells, and are believed to enter the nucleus by passing through the nuclear pore complex. While numerous virally encoded elements have been proposed to be involved in HIV-1 nuclear import, recent evidence has highlighted the importance of HIV-1 capsid. Furthermore, capsid was found to be responsible for the viral requirement of various nuclear transport proteins, including transportin 3 and nucleoporins NUP153 and NUP358, during infection. In this review, we describe our current understanding of retroviral nuclear import, with emphasis on recent developments on the role of the HIV-1 capsid protein.
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Müller B, Heilemann M. Shedding new light on viruses: super-resolution microscopy for studying human immunodeficiency virus. Trends Microbiol 2013; 21:522-33. [PMID: 23916730 DOI: 10.1016/j.tim.2013.06.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 06/20/2013] [Accepted: 06/27/2013] [Indexed: 01/09/2023]
Abstract
For more than 70 years electron microscopy (EM) techniques have played an important role in investigating structures of enveloped viruses. By contrast, use of fluorescence microscopy (FM) methods for this purpose was limited by the fact that the size of virus particles is generally around or below the diffraction limit of light microscopy. Various super-resolution (SR) fluorescence imaging techniques developed over the past two decades bypass the diffraction limit of light microscopy, allowing visualization of subviral details and bridging the gap between conventional FM and EM methods. We summarize here findings on human immunodeficiency virus (HIV-1) obtained using SR-FM techniques. Although the number of published studies is currently limited and some of the pioneering analyses also covered methodological or descriptive aspects, recent publications clearly indicate the potential to approach open questions in HIV-1 replication from a new angle.
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Affiliation(s)
- Barbara Müller
- Department of Infectious Diseases, Virology, University of Heidelberg, Germany.
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Barrow E, Nicola AV, Liu J. Multiscale perspectives of virus entry via endocytosis. Virol J 2013; 10:177. [PMID: 23734580 PMCID: PMC3679726 DOI: 10.1186/1743-422x-10-177] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 05/24/2013] [Indexed: 01/01/2023] Open
Abstract
Most viruses take advantage of endocytic pathways to gain entry into host cells and initiate infections. Understanding of virus entry via endocytosis is critically important for the design of antiviral strategies. Virus entry via endocytosis is a complex process involving hundreds of cellular proteins. The entire process is dictated by events occurring at multiple time and length scales. In this review, we discuss and evaluate the available means to investigate virus endocytic entry, from both experimental and theoretical/numerical modeling fronts, and highlight the importance of multiscale features. The complexity of the process requires investigations at a systems biology level, which involves the combination of different experimental approaches, the collaboration of experimentalists and theorists across different disciplines, and the development of novel multiscale models.
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Affiliation(s)
- Eric Barrow
- School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164, USA
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Sporbert A, Cseresnyes Z, Heidbreder M, Domaing P, Hauser S, Kaltschmidt B, Kaltschmidt C, Heilemann M, Widera D. Simple method for sub-diffraction resolution imaging of cellular structures on standard confocal microscopes by three-photon absorption of quantum dots. PLoS One 2013; 8:e64023. [PMID: 23700448 PMCID: PMC3660314 DOI: 10.1371/journal.pone.0064023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 04/08/2013] [Indexed: 11/20/2022] Open
Abstract
This study describes a simple technique that improves a recently developed 3D sub-diffraction imaging method based on three-photon absorption of commercially available quantum dots. The method combines imaging of biological samples via tri-exciton generation in quantum dots with deconvolution and spectral multiplexing, resulting in a novel approach for multi-color imaging of even thick biological samples at a 1.4 to 1.9-fold better spatial resolution. This approach is realized on a conventional confocal microscope equipped with standard continuous-wave lasers. We demonstrate the potential of multi-color tri-exciton imaging of quantum dots combined with deconvolution on viral vesicles in lentivirally transduced cells as well as intermediate filaments in three-dimensional clusters of mouse-derived neural stem cells (neurospheres) and dense microtubuli arrays in myotubes formed by stacks of differentiated C2C12 myoblasts.
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Affiliation(s)
- Anje Sporbert
- Confocal and 2-Photon Microscopy Core Facility, Max-Delbrueck-Center for Molecular Medicine Berlin, Berlin, Germany
- * E-mail: (AS); (DW)
| | - Zoltan Cseresnyes
- Confocal and 2-Photon Microscopy Core Facility, Max-Delbrueck-Center for Molecular Medicine Berlin, Berlin, Germany
| | - Meike Heidbreder
- Department of Biotechnology and Biophysics, Julius-Maximilians-Universität, Am Hubland, Würzburg, Germany
| | - Petra Domaing
- Confocal and 2-Photon Microscopy Core Facility, Max-Delbrueck-Center for Molecular Medicine Berlin, Berlin, Germany
| | - Stefan Hauser
- Molecular Neurobiology, University of Bielefeld, Bielefeld, Germany
| | - Barbara Kaltschmidt
- Molecular Neurobiology, University of Bielefeld, Bielefeld, Germany
- LiMiTec, Light Microscopy Technology Platform, University of Bielefeld, Bielefeld, Germany
| | - Christian Kaltschmidt
- LiMiTec, Light Microscopy Technology Platform, University of Bielefeld, Bielefeld, Germany
- Cell Biology, University of Bielefeld, Bielefeld, Germany
| | - Mike Heilemann
- Physical and Theoretical Chemistry, Goethe-University Frankfurt, Frankfurt/Main, Germany
| | - Darius Widera
- LiMiTec, Light Microscopy Technology Platform, University of Bielefeld, Bielefeld, Germany
- Cell Biology, University of Bielefeld, Bielefeld, Germany
- * E-mail: (AS); (DW)
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Clustering and mobility of HIV-1 Env at viral assembly sites predict its propensity to induce cell-cell fusion. J Virol 2013; 87:7516-25. [PMID: 23637402 DOI: 10.1128/jvi.00790-13] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
HIV-1 Env mediates virus attachment to and fusion with target cell membranes, and yet, while Env is still situated at the plasma membrane of the producer cell and before its incorporation into newly formed particles, Env already interacts with the viral receptor CD4 on target cells, thus enabling the formation of transient cell contacts that facilitate the transmission of viral particles. During this first encounter with the receptor, Env must not induce membrane fusion, as this would prevent the producer cell and the target cell from separating upon virus transmission, but how Env's fusion activity is controlled remains unclear. To gain a better understanding of the Env regulation that precedes viral transmission, we examined the nanoscale organization of Env at the surface of producer cells. Utilizing superresolution microscopy (stochastic optical reconstruction microscopy [STORM]) and fluorescence recovery after photobleaching (FRAP), we quantitatively assessed the clustering and dynamics of Env upon its arrival at the plasma membrane. We found that Gag assembly induced the aggregation of small Env clusters into larger domains and that these domains were completely immobile. Truncation of the cytoplasmic tail (CT) of Env abrogated Gag's ability to induce Env clustering and restored Env mobility at assembly sites, both of which correlated with increased Env-induced fusion of infected and uninfected cells. Hence, while Env trapping by Gag secures Env incorporation into viral particles, Env clustering and its sequestration at assembly sites likely also leads to the repression of its fusion function, and thus, by preventing the formation of syncytia, Gag helps to secure efficient transfer of viral particles to target cells.
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Super-resolution microscopy reveals specific recruitment of HIV-1 envelope proteins to viral assembly sites dependent on the envelope C-terminal tail. PLoS Pathog 2013; 9:e1003198. [PMID: 23468635 PMCID: PMC3585150 DOI: 10.1371/journal.ppat.1003198] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2012] [Accepted: 01/03/2013] [Indexed: 12/13/2022] Open
Abstract
The inner structural Gag proteins and the envelope (Env) glycoproteins of human immunodeficiency virus (HIV-1) traffic independently to the plasma membrane, where they assemble the nascent virion. HIV-1 carries a relatively low number of glycoproteins in its membrane, and the mechanism of Env recruitment and virus incorporation is incompletely understood. We employed dual-color super-resolution microscopy visualizing Gag assembly sites and HIV-1 Env proteins in virus-producing and in Env expressing cells. Distinctive HIV-1 Gag assembly sites were readily detected and were associated with Env clusters that always extended beyond the actual Gag assembly site and often showed enrichment at the periphery and surrounding the assembly site. Formation of these Env clusters depended on the presence of other HIV-1 proteins and on the long cytoplasmic tail (CT) of Env. CT deletion, a matrix mutation affecting Env incorporation or Env expression in the absence of other HIV-1 proteins led to much smaller Env clusters, which were not enriched at viral assembly sites. These results show that Env is recruited to HIV-1 assembly sites in a CT-dependent manner, while Env(ΔCT) appears to be randomly incorporated. The observed Env accumulation surrounding Gag assemblies, with a lower density on the actual bud, could facilitate viral spread in vivo. Keeping Env molecules on the nascent virus low may be important for escape from the humoral immune response, while cell-cell contacts mediated by surrounding Env molecules could promote HIV-1 transmission through the virological synapse.
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Linnik O, Liesche J, Tilsner J, Oparka KJ. Unraveling the structure of viral replication complexes at super-resolution. FRONTIERS IN PLANT SCIENCE 2013; 4:6. [PMID: 23386855 PMCID: PMC3560349 DOI: 10.3389/fpls.2013.00006] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 01/09/2013] [Indexed: 05/20/2023]
Abstract
During infection, many RNA viruses produce characteristic inclusion bodies that contain both viral and host components. These structures were first described over a century ago and originally termed "X-bodies," as their function was not immediately appreciated. Whilst some inclusion bodies may represent cytopathic by-products of viral protein over-accumulation, X-bodies have emerged as virus "factories," quasi-organelles that coordinate diverse viral infection processes such as replication, protein expression, evasion of host defenses, virion assembly, and intercellular transport. Accordingly, they are now generally referred to as viral replication complexes (VRCs). We previously used confocal fluorescence microscopy to unravel the complex structure of X-bodies produced by Potato virus X (PVX). Here we used 3D-structured illumination (3D-SIM) super-resolution microscopy to map the PVX X-body at a finer scale. We identify a previously unrecognized membrane structure induced by the PVX "triple gene block" (TGB) proteins, providing new insights into the complex interplay between virus and host within the X-body.
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Affiliation(s)
- Olga Linnik
- Institute of Molecular Plant Sciences, University of EdinburghEdinburgh, UK
| | - Johannes Liesche
- Faculty of Life Sciences, University of CopenhagenFrederiksberg C, Denmark
| | - Jens Tilsner
- Biomedical Sciences Research Complex, University of St AndrewsFife, UK
- Cell and Molecular Sciences, The James Hutton InstituteDundee, UK
| | - Karl J. Oparka
- Institute of Molecular Plant Sciences, University of EdinburghEdinburgh, UK
- *Correspondence: Karl J. Oparka, Institute of Molecular Plant Sciences, University of Edinburgh, King’s Buildings, Mayfield Road, Edinburgh EH9 3JR, UK. e-mail:
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