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1.
Viruses ; 16(5)2024 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-38793550

RESUMO

Rotavirus (RV) replicates within viroplasms, membraneless electron-dense globular cytosolic inclusions with liquid-liquid phase properties. In these structures occur the virus transcription, replication, and packaging of the virus genome in newly assembled double-layered particles. The viroplasms are composed of virus proteins (NSP2, NSP5, NSP4, VP1, VP2, VP3, and VP6), single- and double-stranded virus RNAs, and host components such as microtubules, perilipin-1, and chaperonins. The formation, coalescence, maintenance, and perinuclear localization of viroplasms rely on their association with the cytoskeleton. A stabilized microtubule network involving microtubules and kinesin Eg5 and dynein molecular motors is associated with NSP5, NSP2, and VP2, facilitating dynamic processes such as viroplasm coalescence and perinuclear localization. Key post-translation modifications, particularly phosphorylation events of RV proteins NSP5 and NSP2, play pivotal roles in orchestrating these interactions. Actin filaments also contribute, triggering the formation of the viroplasms through the association of soluble cytosolic VP4 with actin and the molecular motor myosin. This review explores the evolving understanding of RV replication, emphasizing the host requirements essential for viroplasm formation and highlighting their dynamic interplay within the host cell.


Assuntos
Citoesqueleto , Rotavirus , Replicação Viral , Rotavirus/fisiologia , Rotavirus/metabolismo , Rotavirus/genética , Citoesqueleto/metabolismo , Citoesqueleto/virologia , Humanos , Animais , Microtúbulos/metabolismo , Microtúbulos/virologia , Proteínas Virais/metabolismo , Proteínas Virais/genética , Interações Hospedeiro-Patógeno , Proteínas não Estruturais Virais/metabolismo , Proteínas não Estruturais Virais/genética , Compartimentos de Replicação Viral/metabolismo , Infecções por Rotavirus/virologia , RNA Viral/genética , RNA Viral/metabolismo
2.
J Med Virol ; 96(4): e29620, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38647027

RESUMO

Vertical transmission has been described following monkeypox virus (MPXV) infection in pregnant women. The presence of MPXV has been reported in the placenta from infected women, but whether pathogens colonize placenta remains unexplored. We identify trophoblasts as a target cell for MPXV replication. In a pan-microscopy approach, we decipher the specific infectious cycle of MPXV and inner cellular structures in trophoblasts. We identified the formation of a specialized region for viral morphogenesis and replication in placental cells. We also reported infection-induced cellular remodeling. We found that MPXV stimulates cytoskeleton reorganization with intercellular extensions for MPXV cell spreading specifically to trophoblastic cells. Altogether, the specific infectious cycle of MPXV in trophoblast cells and these protrusions that were structurally and morphologically similar to filopodia reveal new insights into the infection of MPXV.


Assuntos
Monkeypox virus , Pseudópodes , Trofoblastos , Trofoblastos/virologia , Humanos , Pseudópodes/virologia , Feminino , Gravidez , Monkeypox virus/fisiologia , Liberação de Vírus , Replicação Viral , Citoesqueleto/virologia , Placenta/virologia , Placenta/citologia , Vírion/ultraestrutura , Microscopia/métodos , Linhagem Celular
3.
J Virol ; 96(12): e0220521, 2022 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-35638850

RESUMO

The pathogenesis of white spot syndrome virus (WSSV) is largely unclear. In this study, we found that actin nucleation and clathrin-mediated endocytosis were recruited for internalization of WSSV into crayfish hematopoietic tissue (Hpt) cells. This internalization was followed by intracellular transport of the invading virions via endocytic vesicles and endosomes. After envelope fusion within endosomes, the penetrated nucleocapsids were transported along microtubules toward the periphery of the nuclear pores. Furthermore, the nuclear transporter CqImportin α1/ß1, via binding of ARM repeat domain within CqImportin α1 to the nuclear localization sequences (NLSs) of viral cargoes and binding of CqImportin ß1 to the nucleoporins CqNup35/62 with the action of CqRan for docking to nuclear pores, was hijacked for both targeting of the incoming nucleocapsids toward the nuclear pores and import of the expressed viral structural proteins containing NLS into the cell nucleus. Intriguingly, dysfunction of CqImportin α1/ß1 resulted in significant accumulation of incoming nucleocapsids on the periphery of the Hpt cell nucleus, leading to substantially decreased introduction of the viral genome into the nucleus and remarkably reduced nuclear import of expressed viral structural proteins with NLS; both of these effects were accompanied by significantly inhibited viral propagation. Accordingly, the survival rate of crayfish post-WSSV challenge was significantly increased after dysfunction of CqImportin α1/ß1, also showing significantly reduced viral propagation, and was induced either by gene silencing or by pharmacological blockade via dietary administration of ivermectin per os. Collectively, our findings improve our understanding of WSSV pathogenesis and support future antiviral designing against WSSV. IMPORTANCE As one of the largest animal DNA viruses, white spot syndrome virus (WSSV) has been causing severe economical loss in aquaculture due to the limited knowledge on WSSV pathogenesis for an antiviral strategy. We demonstrate that the actin cytoskeleton, endocytic vesicles, endosomes, and microtubules are hijacked for WSSV invasion; importantly, the nuclear transporter CqImportin α1/ß1 together with CqRan were recruited, via binding of CqImportin ß1 to the nucleoporins CqNup35/62, for both the nuclear pore targeting of the incoming nucleocapsids and the nuclear import of expressed viral structural proteins containing the nuclear localization sequences (NLSs). This is the first report that NLSs from both viral structure proteins and host factor are elaborately recruited together to facilitate WSSV infection. Our findings provide a novel explanation for WSSV pathogenesis involving systemic hijacking of host factors, which can be used for antiviral targeting against WSSV disease, such as the blockade of CqImportin α1/ß1 with ivermectin.


Assuntos
Transporte Ativo do Núcleo Celular , Citoesqueleto , Proteínas Estruturais Virais , Vírus da Síndrome da Mancha Branca 1 , Animais , Antivirais , Astacoidea/virologia , Citoesqueleto/virologia , Ivermectina , Microtúbulos , Complexo de Proteínas Formadoras de Poros Nucleares , Replicação Viral , Vírus da Síndrome da Mancha Branca 1/patogenicidade
4.
Microbiol Spectr ; 10(1): e0226521, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-35138149

RESUMO

Avian hepatitis E virus (HEV) causes liver diseases and multiple extrahepatic disorders in chickens. However, the mechanisms involved in avian HEV entry remain elusive. Herein, we identified the RAS-related protein 1b (Rap1b) as a potential HEV-ORF2 protein interacting candidate. Experimental infection of chickens and cells with an avian HEV isolate from China (CaHEV) led to upregulated expression and activation of Rap1b both in vivo and in vitro. By using CaHEV capsid as mimic of virion to treat cell in vitro, it appears that the interaction between the viral capsid and Rap1b promoted cell membrane recruitment of the downstream effector Rap1-interacting molecule (RIAM). In turn, RIAM further enhanced Talin-1 membrane recruitment and retention, which led to the activation of integrin α5/ß1, as well as integrin-associated membrane protein kinases, including focal adhesion kinase (FAK). Meanwhile, FAK activation triggered activation of downstream signaling molecules, such as Ras-related C3 botulinum toxin substrate 1 RAC1 cell division cycle 42 (CDC42), p21-activated kinase 1 (PAK1), and LIM domain kinase 1 (LIMK1). Finally, F-actin rearrangement induced by Cofilin led to the formation of lamellipodia, filopodia, and stress fibers, contributes to plasma membrane remodeling, and might enhance CaHEV virion internalization. In conclusion, our data suggested that Rap1b activation was triggered during CaHEV infection and appeared to require interaction between CaHEV-ORF2 and Rap1b, thereby further inducing membrane recruitment of Talin-1. Membrane-bound Talin-1 then activates key Integrin-FAK-Cofilin cascades involved in modulation of actin kinetics, and finally leads to F-actin rearrangement and membrane remodeling to potentially facilitate internalization of CaHEV virions into permissive cells. IMPORTANCE Rap1b is a multifunctional protein that is responsible for cell adhesion, growth, and differentiation. The inactive form of Rap1b is phosphorylated and distributed in the cytoplasm, while active Rap1b is prenylated and loaded with GTP to the cell membrane. In this study, the activation of Rap1b was induced during the early stage of avian HEV infection under the regulation of PKA and SmgGDS. Continuously activated Rap1b recruited its effector RIAM to the membrane, thereby inducing the membrane recruitment of Talin-1 that led to the activation of membrane α5/ß1 integrins. The triggering of the signaling pathway-associated Integrin α5/ß1-FAK-CDC42&RAC1-PAK1-LIMK1-Cofilin culminated in F-actin polymerization and membrane remodeling that might promote avian HEV virion internalization. These findings suggested a novel mechanism that is potentially utilized by avian HEV to invade susceptible cells.


Assuntos
Citoesqueleto/metabolismo , Hepatite Viral Animal/metabolismo , Hepevirus/patogenicidade , Doenças das Aves Domésticas/metabolismo , Proteínas Virais/metabolismo , Internalização do Vírus , Proteínas rap de Ligação ao GTP/metabolismo , Actinas/genética , Actinas/metabolismo , Animais , Galinhas , Citoesqueleto/genética , Citoesqueleto/virologia , Hepatite Viral Animal/genética , Hepatite Viral Animal/virologia , Hepevirus/genética , Interações Hospedeiro-Patógeno , Doenças das Aves Domésticas/genética , Doenças das Aves Domésticas/virologia , Ligação Proteica , Proteínas Virais/genética , Proteína cdc42 de Ligação ao GTP/genética , Proteína cdc42 de Ligação ao GTP/metabolismo , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismo , Proteínas rap de Ligação ao GTP/genética
5.
Viruses ; 13(8)2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34452522

RESUMO

Viruses are excellent manipulators of host cellular machinery, behavior, and life cycle, with the host cell cytoskeleton being a primordial viral target. Viruses infecting insects generally enter host cells through clathrin-mediated endocytosis or membrane fusion mechanisms followed by transport of the viral particles to the corresponding replication sites. After viral replication, the viral progeny egresses toward adjacent cells and reaches the different target tissues. Throughout all these steps, actin and tubulin re-arrangements are driven by viruses. The mechanisms used by viruses to manipulate the insect host cytoskeleton are well documented in the case of alphabaculoviruses infecting Lepidoptera hosts and plant viruses infecting Hemiptera vectors, but they are not well studied in case of other insect-virus systems such as arboviruses-mosquito vectors. Here, we summarize the available knowledge on how viruses manipulate the insect host cell cytoskeleton, and we emphasize the primordial role of cytoskeleton components in insect virus motility and the need to expand the study of this interaction.


Assuntos
Vírus de Insetos/fisiologia , Insetos/virologia , Animais , Citoesqueleto/virologia , Interações Hospedeiro-Patógeno , Vírus de Insetos/genética , Insetos/fisiologia
6.
Retrovirology ; 18(1): 19, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34229718

RESUMO

Microtubules (MTs) form a filamentous array that provide both structural support and a coordinated system for the movement and organization of macromolecular cargos within the cell. As such, they play a critical role in regulating a wide range of cellular processes, from cell shape and motility to cell polarization and division. The array is radial with filament minus-ends anchored at perinuclear MT-organizing centers and filament plus-ends continuously growing and shrinking to explore and adapt to the intracellular environment. In response to environmental cues, a small subset of these highly dynamic MTs can become stabilized, acquire post-translational modifications and act as specialized tracks for cargo trafficking. MT dynamics and stability are regulated by a subset of highly specialized MT plus-end tracking proteins, known as +TIPs. Central to this is the end-binding (EB) family of proteins which specifically recognize and track growing MT plus-ends to both regulate MT polymerization directly and to mediate the accumulation of a diverse array of other +TIPs at MT ends. Moreover, interaction of EB1 and +TIPs with actin-MT cross-linking factors coordinate changes in actin and MT dynamics at the cell periphery, as well as during the transition of cargos from one network to the other. The inherent structural polarity of MTs is sensed by specialized motor proteins. In general, dynein directs trafficking of cargos towards the minus-end while most kinesins direct movement toward the plus-end. As a pathogenic cargo, HIV-1 uses the actin cytoskeleton for short-range transport most frequently at the cell periphery during entry before transiting to MTs for long-range transport to reach the nucleus. While the fundamental importance of MT networks to HIV-1 replication has long been known, recent work has begun to reveal the underlying mechanistic details by which HIV-1 engages MTs after entry into the cell. This includes mimicry of EB1 by capsid (CA) and adaptor-mediated engagement of dynein and kinesin motors to elegantly coordinate early steps in infection that include MT stabilization, uncoating (conical CA disassembly) and virus transport toward the nucleus. This review discusses recent advances in our understanding of how MT regulators and their associated motors are exploited by incoming HIV-1 capsid during early stages of infection.


Assuntos
Capsídeo/metabolismo , Citoesqueleto/virologia , HIV-1/metabolismo , Interações Hospedeiro-Patógeno , Microtúbulos/virologia , Transporte Biológico , Proteínas do Capsídeo/metabolismo , Citoesqueleto/metabolismo , Humanos
7.
Plant Cell Rep ; 40(7): 1247-1267, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34028582

RESUMO

KEY MESSAGE: PSV infection changed the abundance of host plant's transcripts and proteins associated with various cellular compartments, including ribosomes, chloroplasts, mitochondria, the nucleus and cytosol, affecting photosynthesis, translation, transcription, and splicing. Virus infection is a process resulting in numerous molecular, cellular, and physiological changes, a wide range of which can be analyzed due to development of many high-throughput techniques. Plant RNA viruses are known to replicate in the cytoplasm; however, the roles of chloroplasts and other cellular structures in the viral replication cycle and in plant antiviral defense have been recently emphasized. Therefore, the aim of this study was to analyze the small RNAs, transcripts, proteins, and phosphoproteins affected during peanut stunt virus strain P (PSV-P)-Nicotiana benthamiana interactions with or without satellite RNA (satRNA) in the context of their cellular localization or functional connections with particular cellular compartments to elucidate the compartments most affected during pathogenesis at the early stages of infection. Moreover, the processes associated with particular cell compartments were determined. The 'omic' results were subjected to comparative data analyses. Transcriptomic and small RNA (sRNA)-seq data were obtained to provide new insights into PSV-P-satRNA-plant interactions, whereas previously obtained proteomic and phosphoproteomic data were used to broaden the analysis to terms associated with cellular compartments affected by virus infection. Based on the collected results, infection with PSV-P contributed to changes in the abundance of transcripts and proteins associated with various cellular compartments, including ribosomes, chloroplasts, mitochondria, the nucleus and the cytosol, and the most affected processes were photosynthesis, translation, transcription, and mRNA splicing. Furthermore, sRNA-seq and phosphoproteomic analyses indicated that kinase regulation resulted in decreases in phosphorylation levels. The kinases were associated with the membrane, cytoplasm, and nucleus components.


Assuntos
Cucumovirus/patogenicidade , Nicotiana/citologia , Nicotiana/virologia , Biologia de Sistemas/métodos , Núcleo Celular/genética , Núcleo Celular/virologia , Cloroplastos/genética , Cloroplastos/virologia , Citoesqueleto/genética , Citoesqueleto/virologia , Citosol/virologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Interações Hospedeiro-Patógeno/fisiologia , MicroRNAs , Nitrogênio/metabolismo , Fosfoproteínas/metabolismo , Células Vegetais/virologia , Doenças das Plantas/virologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Mapas de Interação de Proteínas/genética , RNA Satélite , Nicotiana/genética
8.
Viruses ; 13(2)2021 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-33499367

RESUMO

The bacterial and archaeal cell surface is decorated with filamentous surface structures that are used for different functions, such as motility, DNA exchange and biofilm formation. Viruses hijack these structures and use them to ride to the cell surface for successful entry. In this review, we describe currently known mechanisms for viral attachment, translocation, and entry via filamentous surface structures. We describe the different mechanisms used to exploit various surface structures bacterial and archaeal viruses. This overview highlights the importance of filamentous structures at the cell surface for entry of prokaryotic viruses.


Assuntos
Archaea/virologia , Vírus de Archaea/fisiologia , Bactérias/virologia , Bacteriófagos/fisiologia , Citoesqueleto/virologia , Proteínas de Fímbrias , Fímbrias Bacterianas/virologia , Flagelos/virologia
9.
J Mol Cell Biol ; 12(12): 968-979, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32717049

RESUMO

The emerging coronavirus (CoV) pandemic is threatening the public health all over the world. Cytoskeleton is an intricate network involved in controlling cell shape, cargo transport, signal transduction, and cell division. Infection biology studies have illuminated essential roles for cytoskeleton in mediating the outcome of host‒virus interactions. In this review, we discuss the dynamic interactions between actin filaments, microtubules, intermediate filaments, and CoVs. In one round of viral life cycle, CoVs surf along filopodia on the host membrane to the entry sites, utilize specific intermediate filament protein as co-receptor to enter target cells, hijack microtubules for transportation to replication and assembly sites, and promote actin filaments polymerization to provide forces for egress. During CoV infection, disruption of host cytoskeleton homeostasis and modification state is tightly connected to pathological processes, such as defective cytokinesis, demyelinating, cilia loss, and neuron necrosis. There are increasing mechanistic studies on cytoskeleton upon CoV infection, such as viral protein‒cytoskeleton interaction, changes in the expression and post-translation modification, related signaling pathways, and incorporation with other host factors. Collectively, these insights provide new concepts for fundamental virology and the control of CoV infection.


Assuntos
Infecções por Coronavirus/virologia , Coronavirus/patogenicidade , Citoesqueleto/virologia , Interações entre Hospedeiro e Microrganismos/fisiologia , Citoesqueleto de Actina/fisiologia , Citoesqueleto de Actina/virologia , Animais , Transporte Biológico Ativo , Encéfalo/patologia , Cílios/patologia , Coronavirus/classificação , Coronavirus/fisiologia , Infecções por Coronavirus/patologia , Infecções por Coronavirus/fisiopatologia , Citoesqueleto/patologia , Citoesqueleto/fisiologia , Humanos , Filamentos Intermediários/fisiologia , Filamentos Intermediários/virologia , Microtúbulos/fisiologia , Microtúbulos/virologia , Modelos Biológicos , Filogenia , Receptores Virais/fisiologia , Transdução de Sinais , Montagem de Vírus , Internalização do Vírus , Replicação Viral
10.
Fungal Genet Biol ; 140: 103385, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32305452

RESUMO

The rice blast fungus Magnaporthe oryzae differentiates a specialized infection structure called an appressorium, which is used to break into plant cells by directed application of enormous turgor force. Appressorium-mediated plant infection requires timely assembly of a higher-order septin ring structure at the base of the appressorium, which is needed to spatially orchestrate appressorium repolarization. Here we use quantitative 4D widefield fluorescence imaging to gain new insight into the spatiotemporal dynamics of septin ring formation, and septin-mediated actin re-organization, during appressorium morphogenesis by M. oryzae. We anticipate that the new knowledge will provide a quantitative framework for dissecting the molecular mechanisms of higher-order septin ring assembly in this devastating plant pathogenic fungus.


Assuntos
Ascomicetos/patogenicidade , Oryza/genética , Doenças das Plantas/genética , Septinas/ultraestrutura , Citoesqueleto/genética , Citoesqueleto/virologia , Proteínas Fúngicas/genética , Morfogênese/genética , Oryza/crescimento & desenvolvimento , Oryza/virologia , Doenças das Plantas/virologia , Septinas/química , Septinas/genética
12.
Viruses ; 12(1)2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-31963544

RESUMO

Influenza viruses are respiratory pathogens that represent a significant threat to public health, despite the large-scale implementation of vaccination programs. It is necessary to understand the detailed and complex interactions between influenza virus and its host cells in order to identify successful strategies for therapeutic intervention. During viral entry, the cellular microenvironment presents invading pathogens with a series of obstacles that must be overcome to infect permissive cells. Influenza hijacks numerous host cell proteins and associated biological pathways during its journey into the cell, responding to environmental cues in order to successfully replicate. The cellular cytoskeleton and its constituent microtubules represent a heavily exploited network during viral infection. Cytoskeletal filaments provide a dynamic scaffold for subcellular viral trafficking, as well as virus-host interactions with cellular machineries that are essential for efficient uncoating, replication, and egress. In addition, influenza virus infection results in structural changes in the microtubule network, which itself has consequences for viral replication. Microtubules, their functional roles in normal cell biology, and their exploitation by influenza viruses will be the focus of this review.


Assuntos
Citoesqueleto/virologia , Interações Hospedeiro-Patógeno , Vírus da Influenza A/patogenicidade , Microtúbulos/fisiologia , Internalização do Vírus , Liberação de Vírus , Citoesqueleto/metabolismo , Humanos , Vírus da Influenza A/fisiologia , Transporte Proteico , Replicação Viral
13.
J Neurovirol ; 25(3): 301-312, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30850975

RESUMO

Human immunodeficiency virus-1 (HIV) infection of the central nervous system damages synapses and promotes axonal injury, ultimately resulting in HIV-associated neurocognitive disorders (HAND). The mechanisms through which HIV causes damage to neurons are still under investigation. The cytoskeleton and associated proteins are fundamental for axonal and dendritic integrity. In this article, we review evidence that HIV proteins, such as the envelope protein gp120 and transactivator of transcription (Tat), impair the structure and function of the neuronal cytoskeleton. Investigation into the effects of viral proteins on the neuronal cytoskeleton may provide a better understanding of HIV neurotoxicity and suggest new avenues for additional therapies.


Assuntos
Complexo AIDS Demência/metabolismo , Complexo AIDS Demência/patologia , Citoesqueleto/virologia , Proteínas do Vírus da Imunodeficiência Humana/metabolismo , Neurônios/virologia , Citoesqueleto/metabolismo , Citoesqueleto/patologia , Humanos , Neurônios/metabolismo , Neurônios/patologia
14.
Virol Sin ; 34(1): 30-41, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30725318

RESUMO

The family of flaviviruses is one of the most medically important groups of emerging arthropod-borne viruses. Host cell cytoskeletons have been reported to have close contact with flaviviruses during virus entry, intracellular transport, replication, and egress process, although many detailed mechanisms are still unclear. This article provides a brief overview of the function of the most prominent flaviviruses-induced or -hijacked cytoskeletal structures including actin, microtubules and intermediate filaments, mainly focus on infection by dengue virus, Zika virus and West Nile virus. We suggest that virus interaction with host cytoskeleton to be an interesting area of future research.


Assuntos
Citoesqueleto/virologia , Infecções por Flavivirus/virologia , Flavivirus/fisiologia , Interações entre Hospedeiro e Microrganismos , Actinas , Animais , Vírus da Dengue/fisiologia , Humanos , Filamentos Intermediários/virologia , Camundongos , Microtúbulos/virologia , Internalização do Vírus , Replicação Viral , Vírus do Nilo Ocidental/fisiologia , Zika virus/fisiologia
15.
Virology ; 528: 118-136, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30597347

RESUMO

Although several reports suggest that the entry of infectious bronchitis virus (IBV) depends on lipid rafts and low pH, the endocytic route and intracellular trafficking are unclear. In this study, we aimed to shed greater light on early steps in IBV infection. By using chemical inhibitors, RNA interference, and dominant negative mutants, we observed that lipid rafts and low pH was indeed required for virus entry; IBV mainly utilized the clathrin mediated endocytosis (CME) for entry; GTPase dynamin 1 was involved in virus containing vesicle scission; and the penetration of IBV into cells led to active cytoskeleton rearrangement. By using R18 labeled virus, we found that virus particles moved along with the classical endosome/lysosome track. Functional inactivation of Rab5 and Rab7 significantly inhibited IBV infection. Finally, by using dual R18/DiOC labeled IBV, we observed that membrane fusion was induced after 1 h.p.i. in late endosome/lysosome.


Assuntos
Endocitose , Endossomos/virologia , Vírus da Bronquite Infecciosa/fisiologia , Lisossomos/virologia , Internalização do Vírus , Animais , Linhagem Celular , Chlorocebus aethiops , Clatrina/metabolismo , Citoesqueleto/virologia , Dinamina I/metabolismo , Concentração de Íons de Hidrogênio , Fusão de Membrana , Microdomínios da Membrana/virologia , Interferência de RNA , Células Vero , Proteínas rab de Ligação ao GTP/metabolismo , Proteínas rab5 de Ligação ao GTP/metabolismo , proteínas de unión al GTP Rab7
16.
Viruses ; 11(1)2019 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-30634554

RESUMO

Influenza A Virus (IAV) is a respiratory virus that causes seasonal outbreaks annually and pandemics occasionally. The main targets of the virus are epithelial cells in the respiratory tract. Like many other viruses, IAV employs the host cell's machinery to enter cells, synthesize new genomes and viral proteins, and assemble new virus particles. The cytoskeletal system is a major cellular machinery, which IAV exploits for its entry to and exit from the cell. However, in some cases, the cytoskeleton has a negative impact on efficient IAV growth. In this review, we highlight the role of cytoskeletal elements in cellular processes that are utilized by IAV in the host cell. We further provide an in-depth summary of the current literature on the roles the cytoskeleton plays in regulating specific steps during the assembly of progeny IAV particles.


Assuntos
Citoesqueleto/fisiologia , Interações Hospedeiro-Patógeno , Vírus da Influenza A/fisiologia , Montagem de Vírus , Actinas/metabolismo , Linhagem Celular , Citoesqueleto/virologia , Células Epiteliais/citologia , Células Epiteliais/virologia , Humanos , Microtúbulos/metabolismo
17.
Sci Rep ; 7(1): 5757, 2017 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-28720756

RESUMO

Pixuna virus (PIXV) is an enzootic member of the Venezuelan Equine Encephalitis Virus complex and belongs to the New World cluster of alphaviruses. Herein we explore the role of the cellular cytoskeleton during PIXV replication. We first identified that PIXV undergoes an eclipse phase consisting of 4 h followed by 20 h of an exponential phase in Vero cells. The infected cells showed morphological changes due to structural modifications in actin microfilaments (MFs) and microtubules (MTs). Cytoskeleton-binding agents, that alter the architecture and dynamics of MFs and MTs, were used to study the role of cytoskeleton on PIXV replication. The virus production was significantly affected (p < 0.05) after treatment with paclitaxel or nocodazole due to changes in the MTs network. Interestingly, disassembly of MFs with cytochalasin D, at early stage of PIXV replication cycle, significantly increased the virus yields in the extracellular medium (p < 0.005). Furthermore, the stabilization of actin network with jasplakinolide had no effect on virus yields. Our results demonstrate that PIXV relies not only on intact MTs for the efficient production of virus, but also on a dynamic actin network during the early steps of viral replication.


Assuntos
Alphavirus/fisiologia , Citoesqueleto/virologia , Microtúbulos/virologia , Replicação Viral , Alphavirus/efeitos dos fármacos , Animais , Chlorocebus aethiops , Citocalasina D/farmacologia , Citoesqueleto/efeitos dos fármacos , Depsipeptídeos/farmacologia , Interações Hospedeiro-Patógeno , Microtúbulos/efeitos dos fármacos , Nocodazol/farmacologia , Paclitaxel/farmacologia , Fatores de Tempo , Moduladores de Tubulina/farmacologia , Células Vero
18.
PLoS One ; 12(6): e0179607, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28622358

RESUMO

In infected cells rotavirus (RV) replicates in viroplasms, cytosolic structures that require a stabilized microtubule (MT) network for their assembly, maintenance of the structure and perinuclear localization. Therefore, we hypothesized that RV could interfere with the MT-breakdown that takes place in mitosis during cell division. Using synchronized RV-permissive cells, we show that RV infection arrests the cell cycle in S/G2 phase, thus favoring replication by improving viroplasms formation, viral protein translation, and viral assembly. The arrest in S/G2 phase is independent of the host or viral strain and relies on active RV replication. RV infection causes cyclin B1 down-regulation, consistent with blocking entry into mitosis. With the aid of chemical inhibitors, the cytoskeleton network was linked to specific signaling pathways of the RV-induced cell cycle arrest. We found that upon RV infection Eg5 kinesin was delocalized from the pericentriolar region to the viroplasms. We used a MA104-Fucci system to identify three RV proteins (NSP3, NSP5, and VP2) involved in cell cycle arrest in the S-phase. Our data indicate that there is a strong correlation between the cell cycle arrest and RV replication.


Assuntos
Pontos de Checagem da Fase G2 do Ciclo Celular , Rotavirus/fisiologia , Pontos de Checagem da Fase S do Ciclo Celular , Transdução de Sinais , Replicação Viral/fisiologia , Animais , Ciclina B1/metabolismo , Citoesqueleto/metabolismo , Citoesqueleto/virologia , Cães , Células HEK293 , Humanos , Cinesinas/metabolismo , Macaca mulatta , Células Madin Darby de Rim Canino , Proteínas Virais/metabolismo
19.
J Virol ; 91(7)2017 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-28100610

RESUMO

The signaling lymphocyte activation molecule F1 (SLAMF1) is both a microbial sensor and entry receptor for measles virus (MeV). Herein, we describe a new role for SLAMF1 to mediate MeV endocytosis that is in contrast with the alternative, and generally accepted, model that MeV genome enters cells only after fusion at the cell surface. We demonstrated that MeV engagement of SLAMF1 induces dramatic but transient morphological changes, most prominently in the formation of membrane blebs, which were shown to colocalize with incoming viral particles, and rearrangement of the actin cytoskeleton in infected cells. MeV infection was dependent on these dynamic cytoskeletal changes as well as fluid uptake through a macropinocytosis-like pathway as chemical inhibition of these processes inhibited entry. Moreover, we identified a role for the RhoA-ROCK-myosin II signaling axis in this MeV internalization process, highlighting a novel role for this recently characterized pathway in virus entry. Our study shows that MeV can hijack a microbial sensor normally involved in bacterial phagocytosis to drive endocytosis using a complex pathway that shares features with canonical viral macropinocytosis, phagocytosis, and mechanotransduction. This uptake pathway is specific to SLAMF1-positive cells and occurs within 60 min of viral attachment. Measles virus remains a significant cause of mortality in human populations, and this research sheds new light on the very first steps of infection of this important pathogen.IMPORTANCE Measles is a significant disease in humans and is estimated to have killed over 200 million people since records began. According to current World Health Organization statistics, it still kills over 100,000 people a year, mostly children in the developing world. The causative agent, measles virus, is a small enveloped RNA virus that infects a broad range of cells during infection. In particular, immune cells are infected via interactions between glycoproteins found on the surface of the virus and SLAMF1, the immune cell receptor. In this study, we have investigated the steps governing entry of measles virus into SLAMF1-positive cells and identified endocytic uptake of viral particles. This research will impact our understanding of morbillivirus-related immunosuppression as well as the application of measles virus as an oncolytic therapeutic.


Assuntos
Endocitose , Vírus do Sarampo/fisiologia , Sarampo/virologia , Membro 1 da Família de Moléculas de Sinalização da Ativação Linfocitária/fisiologia , Células A549 , Caveolinas/metabolismo , Clatrina/metabolismo , Citoesqueleto/ultraestrutura , Citoesqueleto/virologia , Dinamina II , Dinaminas/metabolismo , Células HEK293 , Humanos , Microdomínios da Membrana/virologia , Transdução de Sinais , Vírion/fisiologia , Ligação Viral , Internalização do Vírus
20.
Retrovirology ; 12: 78, 2015 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-26376973

RESUMO

BACKGROUND: HIV-1 replication results in mitochondrial damage that is enhanced during antiretroviral therapy (ART). The onset of HIV-1 replication is regulated by viral protein Tat, a 101-residue protein codified by two exons that elongates viral transcripts. Although the first exon of Tat (aa 1-72) forms itself an active protein, the presence of the second exon (aa 73-101) results in a more competent transcriptional protein with additional functions. RESULTS: Mitochondrial overall functions were analyzed in Jurkat cells stably expressing full-length Tat (Tat101) or one-exon Tat (Tat72). Representative results were confirmed in PBLs transiently expressing Tat101 and in HIV-infected Jurkat cells. The intracellular expression of Tat101 induced the deregulation of metabolism and cytoskeletal proteins which remodeled the function and distribution of mitochondria. Tat101 reduced the transcription of the mtDNA, resulting in low ATP production. The total amount of mitochondria increased likely to counteract their functional impairment. These effects were enhanced when Tat second exon was expressed. CONCLUSIONS: Intracellular Tat altered mtDNA transcription, mitochondrial content and distribution in CD4+ T cells. The importance of Tat second exon in non-transcriptional functions was confirmed. Tat101 may be responsible for mitochondrial dysfunctions found in HIV-1 infected patients.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/virologia , DNA Mitocondrial/genética , HIV-1/fisiologia , Mitocôndrias/ultraestrutura , Produtos do Gene tat do Vírus da Imunodeficiência Humana/genética , Produtos do Gene tat do Vírus da Imunodeficiência Humana/metabolismo , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/ultraestrutura , Citoesqueleto/patologia , Citoesqueleto/virologia , DNA Mitocondrial/metabolismo , Éxons , Glicólise , Humanos , Células Jurkat , Leucócitos Mononucleares , Mitocôndrias/genética
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