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Caldas LA, Carneiro FA, Augusto I, Corrêa IA, da Costa LJ, Miranda K, Tanuri A, de Souza W. SARS-CoV-2 egress from Vero cells: a morphological approach. Histochem Cell Biol 2024; 161:59-67. [PMID: 37736815 DOI: 10.1007/s00418-023-02239-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2023] [Indexed: 09/23/2023]
Abstract
Despite being extensively studied because of the current coronavirus disease 2019 (COVID-19) pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) interactions with mammalian cells are still poorly understood. Furthermore, little is known about this coronavirus cycle within the host cells, particularly the steps that lead to viral egress. This study aimed to shed light on the morphological features of SARS-CoV-2 egress by utilizing transmission and high-resolution scanning electron microscopy, along with serial electron tomography, to describe the route of nascent virions towards the extracellular medium. Electron microscopy revealed that the clusters of viruses in the paracellular space did not seem to result from collective virus release. Instead, virus accumulation was observed on incurved areas of the cell surface, with egress primarily occurring through individual vesicles. Additionally, our findings showed that the emission of long membrane projections, which could facilitate virus surfing in Vero cells infected with SARS-CoV-2, was also observed in non-infected cultures, suggesting that these are constitutive events in this cell lineage.
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Affiliation(s)
- Lucio Ayres Caldas
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Prédio CCS, Bloco C, Subsolo, Cidade Universitária, Rio de Janeiro, RJ, CEP:21941902, Brazil.
- Núcleo Multidisciplinar de Pesquisas em Biologia - NUMPEX-BIO, Campus Duque de Caxias Geraldo Cidade, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Duque de Caxias, RJ, Brazil.
| | - Fabiana Avila Carneiro
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Prédio CCS, Bloco C, Subsolo, Cidade Universitária, Rio de Janeiro, RJ, CEP:21941902, Brazil
- Núcleo Multidisciplinar de Pesquisas em Biologia - NUMPEX-BIO, Campus Duque de Caxias Geraldo Cidade, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Duque de Caxias, RJ, Brazil
| | - Ingrid Augusto
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Prédio CCS, Bloco C, Subsolo, Cidade Universitária, Rio de Janeiro, RJ, CEP:21941902, Brazil
| | - Isadora Alonso Corrêa
- Laboratório de Genética e Imunologia das Infecções Virais, Departamento de Virologia, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Laboratório de Virologia Molecular, Departamento de Genética, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luciana Jesus da Costa
- Laboratório de Genética e Imunologia das Infecções Virais, Departamento de Virologia, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Laboratório de Virologia Molecular, Departamento de Genética, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Kildare Miranda
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Prédio CCS, Bloco C, Subsolo, Cidade Universitária, Rio de Janeiro, RJ, CEP:21941902, Brazil
- Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem (INBEB) and Centro Nacional de Biologia Estutural e Bioimagem (CENABIO), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Amilcar Tanuri
- Laboratório de Virologia Molecular, Departamento de Genética, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Prédio CCS, Bloco C, Subsolo, Cidade Universitária, Rio de Janeiro, RJ, CEP:21941902, Brazil
- Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem (INBEB) and Centro Nacional de Biologia Estutural e Bioimagem (CENABIO), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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Bird LE, Edgington-Mitchell LE, Newton HJ. Eat, prey, love: Pathogen-mediated subversion of lysosomal biology. Curr Opin Immunol 2023; 83:102344. [PMID: 37245414 DOI: 10.1016/j.coi.2023.102344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 04/23/2023] [Accepted: 04/30/2023] [Indexed: 05/30/2023]
Abstract
The mammalian lysosome is classically considered the 'garbage can' of the cell, contributing to clearance of infection through its primary function as a degradative organelle. Intracellular pathogens have evolved several strategies to evade contact with this harsh environment through subversion of endolysosomal trafficking or escape into the cytosol. Pathogens can also manipulate pathways that lead to lysosomal biogenesis or alter the abundance or activity of lysosomal content. This pathogen-driven subversion of lysosomal biology is highly dynamic and depends on a range of factors, including cell type, stage of infection, intracellular niche and pathogen load. The growing body of literature in this field highlights the nuanced and complex relationship between intracellular pathogens and the host lysosome, which is critical for our understanding of infection biology.
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Affiliation(s)
- Lauren E Bird
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC 3000, Australia; Infection Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, VIC 3800, Australia
| | | | - Hayley J Newton
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC 3000, Australia; Infection Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, VIC 3800, Australia.
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3
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Koči J, Novotová M, Sláviková M, Klempa B, Zahradník I. SARS-CoV-2 Exploits Non-Canonical Autophagic Processes to Replicate, Mature, and Egress the Infected Vero E6 Cells. Pathogens 2022; 11:pathogens11121535. [PMID: 36558869 PMCID: PMC9781122 DOI: 10.3390/pathogens11121535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 12/08/2022] [Accepted: 12/10/2022] [Indexed: 12/15/2022] Open
Abstract
The coronavirus transforms the cytoplasm of susceptible cells to support virus replication. It also activates autophagy-like processes, the role of which is not well understood. Here, we studied SARS-CoV-2-infected Vero E6 cells using transmission electron microscopy and autophagy PCR array. After 6-24 h post-infection (hpi), the cytoplasm of infected cells only contained double-membrane vesicles, phagophores, and phagosomes engulfing virus particles and cytoplasmic debris, including damaged mitochondria. The phagosomes interacted with the viral nucleoprotein complex, virus particles, mitochondria, and lipid droplets. The phagosomes transformed into egress vacuoles, which broke through the plasmalemma and discharged the virus particles. The Vero E6 cells exhibited pronounced virus replication at 6 hpi, which stabilized at 18-24 hpi at a high level. The autophagy PCR array tests revealed a significant upregulation of 10 and downregulation of 8 autophagic gene markers out of 84. Altogether, these results underline the importance of autophagy-like processes for SARS-CoV-2 maturation and egress, and point to deviations from a canonical autophagy response.
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Affiliation(s)
- Juraj Koči
- Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences, 84505 Bratislava, Slovakia
- Correspondence: (J.K.); (I.Z.)
| | - Marta Novotová
- Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, 84505 Bratislava, Slovakia
| | - Monika Sláviková
- Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences, 84505 Bratislava, Slovakia
| | - Boris Klempa
- Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences, 84505 Bratislava, Slovakia
- Department of Microbiology and Virology, Faculty of Natural Sciences, Comenius University in Bratislava, 84215 Bratislava, Slovakia
| | - Ivan Zahradník
- Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, 84505 Bratislava, Slovakia
- Correspondence: (J.K.); (I.Z.)
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Lan Y, He W, Wang G, Wang Z, Chen Y, Gao F, Song D. Potential Antiviral Strategy Exploiting Dependence of SARS-CoV-2 Replication on Lysosome-Based Pathway. Int J Mol Sci 2022; 23:ijms23116188. [PMID: 35682877 PMCID: PMC9181800 DOI: 10.3390/ijms23116188] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 05/29/2022] [Accepted: 05/30/2022] [Indexed: 12/04/2022] Open
Abstract
The recent novel coronavirus (SARS-CoV-2) disease (COVID-19) outbreak created a severe public health burden worldwide. Unfortunately, the SARS-CoV-2 variant is still spreading at an unprecedented speed in many countries and regions. There is still a lack of effective treatment for moderate and severe COVID-19 patients, due to a lack of understanding of the SARS-CoV-2 life cycle. Lysosomes, which act as “garbage disposals” for nearly all types of eukaryotic cells, were shown in numerous studies to support SARS-CoV-2 replication. Lysosome-associated pathways are required for virus entry and exit during replication. In this review, we summarize experimental evidence demonstrating a correlation between lysosomal function and SARS-CoV-2 replication, and the development of lysosomal perturbation drugs as anti-SARS-CoV-2 agents.
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Affiliation(s)
- Yungang Lan
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130022, China; (W.H.); (Z.W.); (Y.C.); (F.G.)
- Correspondence: (Y.L.); (D.S.)
| | - Wenqi He
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130022, China; (W.H.); (Z.W.); (Y.C.); (F.G.)
| | - Gaili Wang
- Jilin Academy of Animal Husbandry and Veterinary Medicine, Changchun 130022, China;
| | - Zhenzhen Wang
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130022, China; (W.H.); (Z.W.); (Y.C.); (F.G.)
| | - Yuzhu Chen
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130022, China; (W.H.); (Z.W.); (Y.C.); (F.G.)
| | - Feng Gao
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130022, China; (W.H.); (Z.W.); (Y.C.); (F.G.)
| | - Deguang Song
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130022, China; (W.H.); (Z.W.); (Y.C.); (F.G.)
- Correspondence: (Y.L.); (D.S.)
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5
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Cesar-Silva D, Pereira-Dutra FS, Moraes Giannini AL, Jacques G. de Almeida C. The Endolysosomal System: The Acid Test for SARS-CoV-2. Int J Mol Sci 2022; 23:ijms23094576. [PMID: 35562967 PMCID: PMC9105036 DOI: 10.3390/ijms23094576] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/13/2022] [Accepted: 01/17/2022] [Indexed: 12/16/2022] Open
Abstract
This review aims to describe and discuss the different functions of the endolysosomal system, from homeostasis to its vital role during viral infections. We will initially describe endolysosomal system's main functions, presenting recent data on how its compartments are essential for host defense to explore later how SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) and other coronaviruses subvert these organelles for their benefit. It is clear that to succeed, pathogens' evolution favored the establishment of ways to avoid, escape, or manipulate lysosomal function. The unavoidable coexistence with such an unfriendly milieu imposed on viruses the establishment of a vast array of strategies to make the most out of the invaded cell's machinery to produce new viruses and maneuvers to escape the host's defense system.
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Affiliation(s)
- Daniella Cesar-Silva
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute, Fundação Oswaldo Cruz, Rio de Janeiro 21040-900, Brazil; (D.C.-S.); (F.S.P.-D.)
| | - Filipe S. Pereira-Dutra
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute, Fundação Oswaldo Cruz, Rio de Janeiro 21040-900, Brazil; (D.C.-S.); (F.S.P.-D.)
| | - Ana Lucia Moraes Giannini
- Laboratory of Functional Genomics and Signal Transduction, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, Brazil;
| | - Cecília Jacques G. de Almeida
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute, Fundação Oswaldo Cruz, Rio de Janeiro 21040-900, Brazil; (D.C.-S.); (F.S.P.-D.)
- Correspondence: or
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6
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Prydz K, Saraste J. The life cycle and enigmatic egress of coronaviruses. Mol Microbiol 2022; 117:1308-1316. [PMID: 35434857 PMCID: PMC9321882 DOI: 10.1111/mmi.14907] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 11/30/2022]
Abstract
There has been considerable recent interest in the life cycle of Severe Acute Respiratory Syndrome Coronavirus‐2 (SARS‐CoV‐2), the causative agent of the Covid‐19 pandemic. Practically every step in CoV replication—from cell attachment and uptake via genome replication and expression to virion assembly has been considered as a specific event that potentially could be targeted by existing or novel drugs. Interference with cellular egress of progeny viruses could also be adopted as a possible therapeutic strategy; however, the situation is complicated by the fact that there is no broad consensus on how CoVs find their way out of their host cells. The viral nucleocapsid, consisting of the genomic RNA complexed with nucleocapsid proteins obtains a membrane envelope during virus budding into the lumen of the intermediate compartment (IC) at the endoplasmic reticulum (ER)–Golgi interface. From here, several alternative routes for CoV extracellular release have been proposed. Strikingly, recent studies have shown that CoV infection leads to the disassembly of the Golgi ribbon and the mobilization of host cell compartments and protein machineries that are known to promote Golgi‐independent trafficking to the cell surface. Here, we discuss the life cycle of CoVs with a special focus on different possible pathways for virus egress.
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Affiliation(s)
- Kristian Prydz
- Department of Biosciences, University of Oslo, Norway and Department of Biomedicine and Molecular Imaging Center University of Bergen Norway
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7
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Secretory Vesicles Are the Principal Means of SARS-CoV-2 Egress. Cells 2021; 10:cells10082047. [PMID: 34440816 PMCID: PMC8393858 DOI: 10.3390/cells10082047] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/06/2021] [Accepted: 08/08/2021] [Indexed: 01/01/2023] Open
Abstract
The mechanisms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) egress, similar to those of other coronaviruses, remain poorly understood. The virus buds in intracellular compartments and is therefore thought to be released by the biosynthetic secretory pathway. However, several studies have recently challenged this hypothesis. It has been suggested that coronaviruses, including SARS-CoV-2, use lysosomes for egress. In addition, a focused ion-beam scanning electron microscope (FIB/SEM) study suggested the existence of exit tunnels linking cellular compartments rich in viral particles to the extracellular space resembling those observed for the human immunodeficiency (HIV) in macrophages. Here, we analysed serial sections of Vero cells infected with SARS-CoV-2 by transmission electron microscopy (TEM). We found that SARS-CoV-2 was more likely to exit the cell in small secretory vesicles. Virus trafficking within the cells involves small vesicles, with each generally containing a single virus particle. These vesicles then fuse with the plasma membrane to release the virus into the extracellular space. This work sheds new light on the late stages of the SARS-CoV-2 infectious cycle of potential value for guiding the development of new antiviral strategies.
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Hutchison JM, Capone R, Luu DD, Shah KH, Hadziselimovic A, Van Horn WD, Sanders CR. Recombinant SARS-CoV-2 envelope protein traffics to the trans-Golgi network following amphipol-mediated delivery into human cells. J Biol Chem 2021; 297:100940. [PMID: 34237302 PMCID: PMC8256659 DOI: 10.1016/j.jbc.2021.100940] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 06/29/2021] [Accepted: 07/02/2021] [Indexed: 11/16/2022] Open
Abstract
The severe acute respiratory syndrome coronavirus 2 envelope protein (S2-E) is a conserved membrane protein that is important for coronavirus (CoV) assembly and budding. Here, we describe the recombinant expression and purification of S2-E in amphipol-class amphipathic polymer solutions, which solubilize and stabilize membrane proteins, but do not disrupt membranes. We found that amphipol delivery of S2-E to preformed planar bilayers results in spontaneous membrane integration and formation of viroporin cation channels. Amphipol delivery of the S2-E protein to human cells results in plasma membrane integration, followed by retrograde trafficking to the trans-Golgi network and accumulation in swollen perinuclear lysosomal-associated membrane protein 1-positive vesicles, likely lysosomes. CoV envelope proteins have previously been proposed to manipulate the luminal pH of the trans-Golgi network, which serves as an accumulation station for progeny CoV particles prior to cellular egress via lysosomes. Delivery of S2-E to cells will enable chemical biological approaches for future studies of severe acute respiratory syndrome coronavirus 2 pathogenesis and possibly even development of "Trojan horse" antiviral therapies. Finally, this work also establishes a paradigm for amphipol-mediated delivery of membrane proteins to cells.
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Affiliation(s)
- James M Hutchison
- Chemical and Physical Biology Graduate Program, Vanderbilt University, Nashville, Tennessee, USA; Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Ricardo Capone
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, USA; Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Dustin D Luu
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA; The Biodesign Institute Centers for Personalized Diagnostics and Mechanisms of Evolution, Arizona State University, Tempe, Arizona, USA
| | - Karan H Shah
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA; The Biodesign Institute Centers for Personalized Diagnostics and Mechanisms of Evolution, Arizona State University, Tempe, Arizona, USA
| | - Arina Hadziselimovic
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, USA; Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Wade D Van Horn
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA; The Biodesign Institute Centers for Personalized Diagnostics and Mechanisms of Evolution, Arizona State University, Tempe, Arizona, USA.
| | - Charles R Sanders
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, USA; Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA; Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
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9
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Wang X, Melino G, Shi Y. Actively or passively deacidified lysosomes push β-coronavirus egress. Cell Death Dis 2021; 12:235. [PMID: 33664221 PMCID: PMC7930523 DOI: 10.1038/s41419-021-03501-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 01/28/2021] [Accepted: 02/03/2021] [Indexed: 12/11/2022]
Affiliation(s)
- Xuefeng Wang
- The Third Affiliated Hospital of Soochow University and State Key Laboratory of Radiation Medicine and Protection, Institutes for Translational Medicine, Soochow University, 199 Renai Road, 215123, Suzhou, Jiangsu, China.,CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 320 Yueyang Road, 200031, Shanghai, China
| | - Gerry Melino
- Department of Experimental Medicine, TOR, University of Rome Tor Vergata, Rome, 00133, Italy
| | - Yufang Shi
- The Third Affiliated Hospital of Soochow University and State Key Laboratory of Radiation Medicine and Protection, Institutes for Translational Medicine, Soochow University, 199 Renai Road, 215123, Suzhou, Jiangsu, China. .,CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 320 Yueyang Road, 200031, Shanghai, China. .,Department of Experimental Medicine, TOR, University of Rome Tor Vergata, Rome, 00133, Italy.
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Sanyal S. How SARS-CoV-2 (COVID-19) spreads within infected hosts - what we know so far. Emerg Top Life Sci 2020; 4:371-378. [PMID: 33269805 PMCID: PMC7733667 DOI: 10.1042/etls20200165] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/04/2020] [Accepted: 11/09/2020] [Indexed: 01/08/2023]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of the ongoing pandemic of coronavirus disease 2019 (COVID-19), belongs to the betacoronavirus genus and shares high homology to the severe acute respiratory syndrome coronavirus (SARS-CoV) that emerged in 2003. These are highly transmissible and pathogenic viruses which very likely originated in bats. SARS-CoV-2 uses the same receptor, angiotensin-converting enzyme 2 (ACE2) as SARS-CoV, and spreads primarily through the respiratory tract. Although several trials for vaccine development are currently underway, investigations into the virology of SARS-CoV-2 to understand the fundamental biology of the infectious cycle and the associated immunopathology underlying the clinical manifestations of COVID-19 are crucial for identification and rational design of effective therapies. This review provides an overview of how SARS-CoV-2 infects and spreads within human hosts with specific emphasis on key aspects of its lifecycle, tropism and immunopathological features.
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Affiliation(s)
- Sumana Sanyal
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, U.K
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11
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β-Coronaviruses Use Lysosomes for Egress Instead of the Biosynthetic Secretory Pathway. Cell 2020; 183:1520-1535.e14. [PMID: 33157038 PMCID: PMC7590812 DOI: 10.1016/j.cell.2020.10.039] [Citation(s) in RCA: 362] [Impact Index Per Article: 90.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/11/2020] [Accepted: 10/22/2020] [Indexed: 12/27/2022]
Abstract
β-Coronaviruses are a family of positive-strand enveloped RNA viruses that includes the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Much is known regarding their cellular entry and replication pathways, but their mode of egress remains uncertain. Using imaging methodologies and virus-specific reporters, we demonstrate that β-coronaviruses utilize lysosomal trafficking for egress rather than the biosynthetic secretory pathway more commonly used by other enveloped viruses. This unconventional egress is regulated by the Arf-like small GTPase Arl8b and can be blocked by the Rab7 GTPase competitive inhibitor CID1067700. Such non-lytic release of β-coronaviruses results in lysosome deacidification, inactivation of lysosomal degradation enzymes, and disruption of antigen presentation pathways. β-Coronavirus-induced exploitation of lysosomal organelles for egress provides insights into the cellular and immunological abnormalities observed in patients and suggests new therapeutic modalities.
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12
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Lee JH, An HK, Sohn MG, Kivela P, Oh S. 4,4'-Diaminodiphenyl Sulfone (DDS) as an Inflammasome Competitor. Int J Mol Sci 2020; 21:E5953. [PMID: 32824985 PMCID: PMC7503668 DOI: 10.3390/ijms21175953] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/13/2020] [Accepted: 08/17/2020] [Indexed: 02/06/2023] Open
Abstract
The aim of this study is to examine the use of an inflammasome competitor as a preventative agent. Coronaviruses have zoonotic potential due to the adaptability of their S protein to bind receptors of other species, most notably demonstrated by SARS-CoV. The binding of SARS-CoV-2 to TLR (Toll-like receptor) causes the release of pro-IL-1β, which is cleaved by caspase-1, followed by the formation and activation of the inflammasome, which is a mediator of lung inflammation, fever, and fibrosis. The NLRP3 (NACHT, LRR and PYD domains-containing protein 3) inflammasome is implicated in a variety of human diseases including Alzheimer's disease (AD), prion diseases, type 2 diabetes, and numerous infectious diseases. By examining the use of 4,4'-diaminodiphenyl sulfone (DDS) in the treatment of patients with Hansen's disease, also diagnosed as Alzheimer's disease, this study demonstrates the diverse mechanisms involved in the activation of inflammasomes. TLRs, due to genetic polymorphisms, can alter the immune response to a wide variety of microbial ligands, including viruses. In particular, TLR2Arg677Trp was reported to be exclusively present in Korean patients with lepromatous leprosy (LL). Previously, mutation of the intracellular domain of TLR2 has demonstrated its role in determining the susceptibility to LL, though LL was successfully treated using a combination of DDS with rifampicin and clofazimine. Of the three tested antibiotics, DDS was effective in the molecular regulation of NLRP3 inflammasome activators that are important in mild cognitive impairment (MCI), Parkinson's disease (PD), and AD. The specific targeting of NLRP3 itself or up-/downstream factors of the NLRP3 inflammasome by DDS may be responsible for its observed preventive effects, functioning as a competitor.
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Affiliation(s)
- Jong-hoon Lee
- Science and Research Center, Seoul National University College of Medicine, Seoul 03080, Korea;
| | - Ha Kyeu An
- Department of Neurology, Sorokdo National Hospital, Jeollanam-do 59562, Korea;
| | - Mun-Gi Sohn
- Department of Food Science, KyungHee University College of Life Science, Seoul 17104, Korea;
| | - Paul Kivela
- Department of Emergency Medicine, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Sangsuk Oh
- Department of Food Engineering, Food Safety Laboratory, Memory Unit, Ewha Womans University, Seoul 03670, Korea
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Uludağ H, Parent K, Aliabadi HM, Haddadi A. Prospects for RNAi Therapy of COVID-19. Front Bioeng Biotechnol 2020; 8:916. [PMID: 32850752 PMCID: PMC7409875 DOI: 10.3389/fbioe.2020.00916] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 07/15/2020] [Indexed: 12/12/2022] Open
Abstract
COVID-19 caused by the SARS-CoV-2 virus is a fast emerging disease with deadly consequences. The pulmonary system and lungs in particular are most prone to damage caused by the SARS-CoV-2 infection, which leaves a destructive footprint in the lung tissue, making it incapable of conducting its respiratory functions and resulting in severe acute respiratory disease and loss of life. There were no drug treatments or vaccines approved for SARS-CoV-2 at the onset of pandemic, necessitating an urgent need to develop effective therapeutics. To this end, the innate RNA interference (RNAi) mechanism can be employed to develop front line therapies against the virus. This approach allows specific binding and silencing of therapeutic targets by using short interfering RNA (siRNA) and short hairpin RNA (shRNA) molecules. In this review, we lay out the prospect of the RNAi technology for combatting the COVID-19. We first summarize current understanding of SARS-CoV-2 virology and the host response to viral entry and duplication, with the purpose of revealing effective RNAi targets. We then summarize the past experience with nucleic acid silencers for SARS-CoV, the predecessor for current SARS-CoV-2. Efforts targeting specific protein-coding regions within the viral genome and intragenomic targets are summarized. Emphasizing non-viral delivery approaches, molecular underpinnings of design of RNAi agents are summarized with comparative analysis of various systems used in the past. Promising viral targets as well as host factors are summarized, and the possibility of modulating the immune system are presented for more effective therapies. We place special emphasis on the limitations of past studies to propel the field faster by focusing on most relevant models to translate the promising agents to a clinical setting. Given the urgency to address lung failure in COVID-19, we summarize the feasibility of delivering promising therapies by the inhalational route, with the expectation that this route will provide the most effective intervention to halt viral spread. We conclude with the authors' perspectives on the future of RNAi therapeutics for combatting SARS-CoV-2. Since time is of the essence, a strong perspective for the path to most effective therapeutic approaches are clearly articulated by the authors.
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Affiliation(s)
- Hasan Uludağ
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Kylie Parent
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada
| | | | - Azita Haddadi
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
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Manjili RH, Zarei M, Habibi M, Manjili MH. COVID-19 as an Acute Inflammatory Disease. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2020; 205:12-19. [PMID: 32423917 PMCID: PMC7333792 DOI: 10.4049/jimmunol.2000413] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 05/06/2020] [Indexed: 02/06/2023]
Abstract
The 2019 coronavirus disease (COVID-19) pandemic caused by the virus severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has created an unprecedented global crisis for the infrastructure sectors, including economic, political, healthcare, education, and research systems. Although over 90% of infected individuals are asymptomatic or manifest noncritical symptoms and will recover from the infection, those individuals presenting with critical symptoms are in urgent need of effective treatment options. Emerging data related to mechanism of severity and potential therapies for patients presenting with severe symptoms are scattered and therefore require a comprehensive analysis to focus research on developing effective therapeutics. A critical literature review suggests that the severity of SARS-CoV-2 infection is associated with dysregulation of inflammatory immune responses, which in turn inhibits the development of protective immunity to the infection. Therefore, the use of therapeutics that modulate inflammation without compromising the adaptive immune response could be the most effective therapeutic strategy.
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Affiliation(s)
| | - Melika Zarei
- Virginia Tech Carilion School of Medicine, Roanoke, VA 24016
| | - Mehran Habibi
- Department of Surgery, Johns Hopkins School of Medicine, Baltimore, MD 20215
| | - Masoud H Manjili
- Department of Microbiology and Immunology, VCU Institute of Molecular Medicine, VCU School of Medicine, Richmond, VA 23298; and
- VCU Massey Cancer Center, Richmond, VA 23298
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Yang N, Shen HM. Targeting the Endocytic Pathway and Autophagy Process as a Novel Therapeutic Strategy in COVID-19. Int J Biol Sci 2020; 16:1724-1731. [PMID: 32226290 PMCID: PMC7098027 DOI: 10.7150/ijbs.45498] [Citation(s) in RCA: 309] [Impact Index Per Article: 77.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 03/03/2020] [Indexed: 12/23/2022] Open
Abstract
Coronaviruses (CoVs) are a group of enveloped, single-stranded positive genomic RNA viruses and some of them are known to cause severe respiratory diseases in human, including Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS) and the ongoing coronavirus disease-19 (COVID-19). One key element in viral infection is the process of viral entry into the host cells. In the last two decades, there is increasing understanding on the importance of the endocytic pathway and the autophagy process in viral entry and replication. As a result, the endocytic pathway including endosome and lysosome has become important targets for development of therapeutic strategies in combating diseases caused by CoVs. In this mini-review, we will focus on the importance of the endocytic pathway as well as the autophagy process in viral infection of several pathogenic CoVs inclusive of SARS-CoV, MERS-CoV and the new CoV named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and discuss the development of therapeutic agents by targeting these processes. Such knowledge will provide important clues for control of the ongoing epidemic of SARS-CoV-2 infection and treatment of COVID-19.
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Affiliation(s)
- Naidi Yang
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing, Jiangsu Province 211800, China
| | - Han-Ming Shen
- Faculty of Health Sciences, University of Macau, Macau SAR, China
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Abstract
Ammonium chloride at a concentration of 20 mM delayed by 4-5 hr the production of virus progeny in mouse L-2 cells infected at high multiplicity with mouse hepatitis virus (MHV). This delay was seen in the production of both intracellular and extracellular virus. However, the final titers were similar to those produced by MHV-infected cells maintained in normal medium. The manifestation of virus-induced cell fusion was similarly found to be delayed, but not otherwise decreased in severity, when ammonium chloride was present in the culture medium. Ammonium chloride caused similar delays in production of virus-specific, positive-sense RNAs and of viral polypeptides. The relative proportions and apparent molecular weights of viral RNAs and polypeptides were similar to those found in MHV-infected cells cultured in normal medium. In vitro translation of endogenously produced viral RNAs in cell extracts, prepared from MHV-infected cells, was not inhibited by ammonium chloride. Thus, ammonium chloride has no specific, inhibitory effect on viral protein synthesis. Ammonium chloride did not reduce the number of virus-infected cells in culture, as monitored by infectious center assay. Analysis of early events in MHV infection showed that ammonium chloride did not affect adsorption or internalization of MHV by L-2 cells. However, the subsequent eclipse phase, as monitored by decline in infectivity of internalized virus inoculum proceeded less efficiently in the presence of ammonium chloride. On the basis of the known inhibitory effects of ammonium chloride on lysosomal/endosomal functions, the results suggest an endosomal mechanism of MHV uncoating. Thus the primary effect of ammonium chloride on MHV infection of L-2 cells is to attenuate virus uncoating, thereby chronologically displacing all subsequent virus-encoded functions.
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