scholarly journals ISG15/USP18/STAT2 is a molecular hub regulating autocrine IFN I-mediated control of Dengue and Zika virus replication

2019 ◽  
Author(s):  
Constanza Eleonora Espada ◽  
Edroaldo Lummertz da Rocha ◽  
Adara Aurea dos Santos ◽  
Zamira Guerra Soares ◽  
Greicy Malaquias ◽  
...  
Keyword(s):  
Virus Replication ◽  
Window Of Opportunity ◽  
Hostile Environment ◽  
Virus Growth ◽  
Binding Partner ◽  
Major Mechanism ◽  
Host Interaction ◽  
Interaction Interface ◽  
Isg15 Expression ◽  
Flavivirus Infection

SUMMARYThe establishment of a virus infection is the result of the pathogen’s ability to replicate in a hostile environment generated by the host’s immune system. Here, we found that ISG15 restricts Dengue and Zika viruses’ replication through the stabilization of its binding partner USP18. ISG15 expression was necessary to control DV replication driven by both autocrine and paracrine type one interferon (IFN-I) signaling. Moreover, USP18 competes with NS5-mediated STAT2 degradation, a major mechanism for establishment of flavivirus infection. Strikingly, reconstitution of USP18 in ISG15-deficient cells was sufficient to restore the cells’ immune response and restrict virus growth, suggesting that the IFNAR-mediated ISG15 activity is also antiviral. Our results add a novel layer of complexity in the virus/host interaction interface and suggest that NS5 has a narrow window of opportunity to degrade STAT2, therefore suppressing host’s IFN-I mediated response and promoting virus replication.

scholarly journals Vector competence is strongly affected by a small deletion or point mutations in bluetongue virus

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
René G. P. van Gennip ◽  
Barbara S. Drolet ◽  
Paula Rozo Lopez ◽  
Ashley J. C. Roost ◽  
Jan Boonstra ◽  
...  
Keyword(s):  
Virus Replication ◽  
Bluetongue Virus ◽  
Vector Competence ◽  
Outer Shell ◽  
Virus Propagation ◽  
Virus Growth ◽  
Shell Protein ◽  
Vector Borne

Abstract Background Transmission of vector-borne virus by insects is a complex mechanism consisting of many different processes; viremia in the host, uptake, infection and dissemination in the vector, and delivery of virus during blood-feeding leading to infection of the susceptible host. Bluetongue virus (BTV) is the prototype vector-borne orbivirus (family Reoviridae). BTV serotypes 1–24 (typical BTVs) are transmitted by competent biting Culicoides midges and replicate in mammalian (BSR) and midge (KC) cells. Previously, we showed that genome segment 10 (S10) encoding NS3/NS3a protein is required for virus propagation in midges. BTV serotypes 25–27 (atypical BTVs) do not replicate in KC cells. Several distinct BTV26 genome segments cause this so-called ‘differential virus replication’ in vitro. Methods Virus strains were generated using reverse genetics and their growth was examined in vitro. The midge feeding model has been developed to study infection, replication and disseminations of virus in vivo. A laboratory colony of C. sonorensis, a known competent BTV vector, was fed or injected with BTV variants and propagation in the midge was examined using PCR testing. Crossing of the midgut infection barrier was examined by separate testing of midge heads and bodies. Results A 100 nl blood meal containing ±105.3 TCID50/ml of BTV11 which corresponds to ±20 TCID50 infected 50% of fully engorged midges, and is named one Midge Alimentary Infective Dose (MAID50). BTV11 with a small in-frame deletion in S10 infected blood-fed midge midguts but virus release from the midgut into the haemolymph was blocked. BTV11 with S1[VP1] of BTV26 could be adapted to virus growth in KC cells, and contained mutations subdivided into ‘corrections’ of the chimeric genome constellation and mutations associated with adaptation to KC cells. In particular one amino acid mutation in outer shell protein VP2 overcomes differential virus replication in vitro and in vivo. Conclusion Small changes in NS3/NS3a or in the outer shell protein VP2 strongly affect virus propagation in midges and thus vector competence. Therefore, spread of disease by competent Culicoides midges can strongly differ for very closely related viruses.

scholarly journals Variable Inhibition of Zika Virus Replication by Different Wolbachia Strains in Mosquito Cell Cultures

2017 ◽  
Vol 91 (14) ◽  
Author(s):  
Michaela J. Schultz ◽  
Sharon Isern ◽  
Scott F. Michael ◽  
Ronald B. Corley ◽  
John H. Connor ◽  
...  
Keyword(s):  
Virus Replication ◽  
Zika Virus ◽  
Western Hemisphere ◽  
Mosquito Cell ◽  
Mosquito Vector ◽  
Viral Inhibition ◽  
Virus Growth ◽  
Content Type ◽  
Bacterial Endosymbiont ◽  
Mosquito Cells

ABSTRACT Mosquito-borne arboviruses are a major source of human disease. One strategy to reduce arbovirus disease is to reduce the mosquito's ability to transmit virus. Mosquito infection with the bacterial endosymbiont Wolbachia pipientis wMel is a novel strategy to reduce Aedes mosquito competency for flavivirus infection. However, experiments investigating cyclic environmental temperatures have shown a reduction in maternal transmission of wMel, potentially weakening the integration of this strain into a mosquito population relative to that of other Wolbachia strains. Consequently, it is important to investigate additional Wolbachia strains. All Zika virus (ZIKV) suppression studies are limited to the wMel Wolbachia strain. Here we show ZIKV inhibition by two different Wolbachia strains: wAlbB (isolated from Aedes albopictus mosquitoes) and wStri (isolated from the planthopper Laodelphax striatellus) in mosquito cells. Wolbachia strain wStri inhibited ZIKV most effectively. Single-cycle infection experiments showed that ZIKV RNA replication and nonstructural protein 5 translation were reduced below the limits of detection in wStri-containing cells, demonstrating early inhibition of virus replication. ZIKV replication was rescued when Wolbachia was inhibited with a bacteriostatic antibiotic. We observed a partial rescue of ZIKV growth when Wolbachia-infected cells were supplemented with cholesterol-lipid concentrate, suggesting competition for nutrients as one of the possible mechanisms of Wolbachia inhibition of ZIKV. Our data show that wAlbB and wStri infection causes inhibition of ZIKV, making them attractive candidates for further in vitro mechanistic and in vivo studies and future vector-centered approaches to limit ZIKV infection and spread. IMPORTANCE Zika virus (ZIKV) has swiftly spread throughout most of the Western Hemisphere. This is due in large part to its replication in and spread by a mosquito vector host. There is an urgent need for approaches that limit ZIKV replication in mosquitoes. One exciting approach for this is to use a bacterial endosymbiont called Wolbachia that can populate mosquito cells and inhibit ZIKV replication. Here we show that two different strains of Wolbachia, wAlbB and wStri, are effective at repressing ZIKV in mosquito cell lines. Repression of virus growth is through the inhibition of an early stage of infection and requires actively replicating Wolbachia. Our findings further the understanding of Wolbachia viral inhibition and provide novel tools that can be used in an effort to limit ZIKV replication in the mosquito vector, thereby interrupting the transmission and spread of the virus.

scholarly journals The Regulation of Flavivirus Infection by Hijacking Exosome-Mediated Cell–Cell Communication: New Insights on Virus–Host Interactions

Viruses ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 765
Author(s):  
José Manuel Reyes-Ruiz ◽  
Juan Fidel Osuna-Ramos ◽  
Luis Adrián De Jesús-González ◽  
Selvin Noé Palacios-Rápalo ◽  
Carlos Daniel Cordero-Rivera ◽  
...  
Keyword(s):  
Viral Infections ◽  
Cell Communication ◽  
Cell Interaction ◽  
Host Cells ◽  
Human Pathogens ◽  
Cellular Functions ◽  
Cellular Targets ◽  
Host Interaction ◽  
Flavivirus Infection

The arthropod-borne flaviviruses are important human pathogens, and a deeper understanding of the virus–host cell interaction is required to identify cellular targets that can be used as therapeutic candidates. It is well reported that the flaviviruses hijack several cellular functions, such as exosome-mediated cell communication during infection, which is modulated by the delivery of the exosomal cargo of pro- or antiviral molecules to the receiving host cells. Therefore, to study the role of exosomes during flavivirus infections is essential, not only to understand its relevance in virus–host interaction, but also to identify molecular factors that may contribute to the development of new strategies to block these viral infections. This review explores the implications of exosomes in flavivirus dissemination and transmission from the vector to human host cells, as well as their involvement in the host immune response. The hypothesis about exosomes as a transplacental infection route of ZIKV and the paradox effect or the dual role of exosomes released during flavivirus infection are also discussed here. Although several studies have been performed in order to identify and characterize cellular and viral molecules released in exosomes, it is not clear how all of these components participate in viral pathogenesis. Further studies will determine the balance between protective and harmful exosomes secreted by flavivirus infected cells, the characteristics and components that distinguish them both, and how they could be a factor that determines the infection outcome.

scholarly journals Improvement of Influenza A/Fujian/411/02 (H3N2) Virus Growth in Embryonated Chicken Eggs by Balancing the Hemagglutinin and Neuraminidase Activities, Using Reverse Genetics

2005 ◽  
Vol 79 (11) ◽  
pp. 6763-6771 ◽  
Author(s):  
Bin Lu ◽  
Helen Zhou ◽  
Dan Ye ◽  
George Kemble ◽  
Hong Jin
Keyword(s):  
Amino Acids ◽  
Virus Replication ◽  
Receptor Binding ◽  
Influenza A ◽  
Reverse Genetics ◽  
Influenza Vaccines ◽  
H3n2 Virus ◽  
Virus Growth ◽  
Chicken Eggs ◽  
Embryonated Chicken

ABSTRACT The H3N2 influenza A/Fujian/411/02-like virus strains that circulated during the 2003-2004 influenza season caused influenza epidemics. Most of the A/Fujian/411/02 virus lineages did not replicate well in embryonated chicken eggs and had to be isolated originally by cell culture. The molecular basis for the poor replication of A/Fujian/411/02 virus was examined in this study by the reverse genetics technology. Two antigenically related strains that replicated well in embryonated chicken eggs, A/Sendai-H/F4962/02 and A/Wyoming/03/03, were compared with the prototype A/Fujian/411/02 virus. A/Sendai differed from A/Fujian by three amino acids in the neuraminidase (NA), whereas A/Wyoming differed from A/Fujian by five amino acids in the hemagglutinin (HA). The HA and NA segments of these three viruses were reassorted with cold-adapted A/Ann Arbor/6/60, the master donor virus for the live attenuated type A influenza vaccines (FluMist). The HA and NA residues differed between these three H3N2 viruses evaluated for their impact on virus replication in MDCK cells and in embryonated chicken eggs. It was determined that replication of A/Fujian/411/02 in eggs could be improved by either changing minimum of two HA residues (G186V and V226I) to increase the HA receptor-binding ability or by changing a minimum of two NA residues (E119Q and Q136K) to lower the NA enzymatic activity. Alternatively, recombinant A/Fujian/411/02 virus could be adapted to grow in eggs by two amino acid substitutions in the HA molecule (H183L and V226A), which also resulted in the increased HA receptor-binding activity. Thus, the balance between the HA and NA activities is critical for influenza virus replication in a different host system. The HA or NA changes that increased A/Fujian/411/02 virus replication in embryonated chicken eggs were found to have no significant impact on antigenicity of these recombinant viruses. This study demonstrated that the reverse genetics technology could be used to improve the manufacture of the influenza vaccines.

scholarly journals Theiler's Virus-Induced Intrinsic Apoptosis in M1-D Macrophages Is Bax Mediated and Restricts Virus Infectivity: a Mechanism for Persistence of a Cytolytic Virus

2008 ◽  
Vol 82 (9) ◽  
pp. 4502-4510 ◽  
Author(s):  
Kyung-No Son ◽  
Robert P. Becker ◽  
Patricia Kallio ◽  
Howard L. Lipton
Keyword(s):  
Virus Infection ◽  
Virus Replication ◽  
Virus Infectivity ◽  
Apoptotic Pathway ◽  
Virus Growth ◽  
The Family ◽  
Encephalomyelitis Virus ◽  
D Cells ◽  
Kinetics Of ◽  
Mouse Central Nervous System

ABSTRACT Theiler's murine encephalomyelitis virus (TMEV), a member of the Cardiovirus genus in the family Picornaviridae, is a highly cytolytic virus that produces necrotic death in rodent cells except for macrophages, which undergo apoptosis. In the present study we have analyzed the kinetics of BeAn virus infection in M1-D cells, in order to temporally relate virus replication to the apoptotic signaling events. Apoptosis was associated with early exponential virus growth from 1 to 12 h postinfection (p.i.); however, ≥80% of peak infectivity was lost by 16 to 24 h p.i. The pan-caspase inhibitor qVD-OPh led to significantly higher virus yields, while zVAD-fmk completely inhibited virus replication until 10 h p.i., precluding its assessment in apoptosis. In contrast, while zVAD-fmk significantly inhibited BeAn virus replication in BHK-21 cells at 12 and 16 h p.i., virus replication at these time points was not altered by qVD-OPh. Bax translocation into mitochondria, efflux of cytochrome c into the cytoplasm, and activation of caspases 9 and 3 between ∼8 and 12 h p.i. (all hallmarks of the intrinsic apoptotic pathway) were transiently inhibited by expression of Bcl-2, which is not expressed in M1-D cells. Thus, BeAn virus infection in M1-D macrophages, which restricts virus replication, provides a potential mechanism for modulating TMEV neurovirulence during persistence in the mouse central nervous system.

scholarly journals Deletion of Nonstructural Proteins NS1 and NS2 from Pneumonia Virus of Mice Attenuates Viral Replication and Reduces Pulmonary Cytokine Expression and Disease

2008 ◽  
Vol 83 (4) ◽  
pp. 1969-1980 ◽  
Author(s):  
Ursula J. Buchholz ◽  
Jerrold M. Ward ◽  
Elaine W. Lamirande ◽  
Britta Heinze ◽  
Christine D. Krempl ◽  
...  
Keyword(s):  
Virus Replication ◽  
Vero Cells ◽  
Type I ◽  
Nonstructural Proteins ◽  
Virus Growth ◽  
Broad Array ◽  
Syncytial Virus ◽  
Inducible Genes ◽  
Overt Disease ◽  
Convenient Model

ABSTRACT Pneumonia virus of mice (PVM) strain 15 causes fatal pneumonia in mice and provides a convenient model for human respiratory syncytial virus pathogenesis and immunobiology. We prepared PVM mutants lacking the genes for nonstructural proteins NS1 and/or NS2. In Vero cells, which lack type I interferon (IFN), deletion of these proteins had no effect on the efficiency of virus growth. In IFN-competent mouse embryo fibroblasts, wild-type (wt) PVM and the ΔNS1 virus grew efficiently and strongly inhibited the IFN response, whereas virus lacking NS2 was highly attenuated and induced high levels of IFN and IFN-inducible genes. In BALB/c mice, intranasal infection with wt PVM caused overt disease that began on day 6 and was lethal by day 9 postinoculation. In comparison, ΔNS1 induced transient, reduced disease, and ΔNS2 and ΔNS12 caused no disease. Thus, NS1 and NS2 are virulence factors, with NS2 being a major antagonist of the type I IFN system. The pulmonary titers of wt PVM and ΔNS1 were high on day 3 and increased further by day 6; in addition, expression of IFN and representative proinflammatory cytokines/chemokines and T lymphocyte-related cytokines was undetectable on day 3 but increased dramatically by day 6 coincident with the onset of disease. The titers of ΔNS2 and ΔNS12 were somewhat lower on day 3 and decreased further by day 6; in addition, these viruses induced a more circumscribed set of cytokines/chemokines (IFN, interleukin-6 [IL-6], and CXCL10) that were detected on day 3 and had largely subsided by day 6. Lung immunohistology revealed abundant PVM-positive pneumocytes and bronchial and bronchiolar epithelial cells in wt PVM- and ΔNS1-infected mice on day 6 compared to few PVM-positive foci with ΔNS2 and ΔNS12. These results indicate that severe PVM disease is associated with high, poorly controlled virus replication driving the expression of high levels of pulmonary IFN and a broad array of cytokines/chemokines. In contrast, in the absence of NS2, there was an early, transient innate response involving moderate levels of IFN, IL-6, and CXCL10 that restricted virus replication and prevented disease.

scholarly journals Expression and Mutational Analysis of Autographa californica Nucleopolyhedrovirus HCF-1: Functional Requirements for Cysteine Residues

2005 ◽  
Vol 79 (22) ◽  
pp. 13900-13914 ◽  
Author(s):  
Joyce A. Wilson ◽  
Scott D. Forney ◽  
Alessondra M. Ricci ◽  
Emily G. Allen ◽  
Kathleen L. Hefferon ◽  
...  
Keyword(s):  
Amino Acids ◽  
Virus Replication ◽  
Mutational Analysis ◽  
Ring Finger ◽  
Autographa Californica ◽  
Gene Repression ◽  
Cysteine Residues ◽  
Specific Factor ◽  
Virus Growth ◽  
Self Association

ABSTRACT The host cell-specific factor 1 gene (hcf-1) of the baculovirus Autographa californica multiple nucleopolyhedrovirus is required for efficient virus growth in TN368 cells but is dispensable for virus replication in SF21 cells. However, the mechanism of action of hcf-1 is unknown. To begin to understand its function in virus replication we have investigated the expression and localization pattern of HCF-1 in infected cells. Analysis of virus-infected TN368 cells showed that hcf-1 is expressed at an early time in the virus life cycle, between 2 and 12 h postinfection, and localized the protein to punctate nuclear foci. Through coprecipitation experiments we have confirmed that HCF-1 self-associates into dimers or higher-order structures. We also found that overexpression of HCF-1 repressed expression from the hcf-1 promoter in transient reporter assays. Mutagenesis of cysteine residues within a putative RING finger domain in the amino acid sequence of HCF-1 abolished self-association activity and suggests that the RING domain may be involved in this protein-protein interaction. A different but overlapping set of cysteine residues were required for efficient gene repression activity. Functional analysis of HCF-1 mutants showed that the cysteine amino acids required for both self-association and gene repression activities of HCF-1 were also required for efficient late-gene expression and occlusion body formation in TN368 cells. Mutational analysis also identified essential charged and hydrophobic amino acids located between two of the essential cysteine residues. We propose that HCF-1 is a RING finger-containing protein whose activity requires HCF-1 self-association and gene repression activity.

scholarly journals Roles of Nonstructural Protein nsP2 and Alpha/Beta Interferons in Determining the Outcome of Sindbis Virus Infection

2002 ◽  
Vol 76 (22) ◽  
pp. 11254-11264 ◽  
Author(s):  
Elena I. Frolova ◽  
Rafik Z. Fayzulin ◽  
Susan H. Cook ◽  
Diane E. Griffin ◽  
Charles M. Rice ◽  
...  
Keyword(s):  
Virus Infection ◽  
Host Cell ◽  
Virus Replication ◽  
Mammalian Cells ◽  
Sindbis Virus ◽  
Nonstructural Protein ◽  
Virus Propagation ◽  
Virus Growth ◽  
Infected Cells ◽  
Alpha Beta

ABSTRACT Alphaviruses productively infect a variety of vertebrate and insect cell lines. In vertebrate cells, Sindbis virus redirects cellular processes to meet the needs of virus propagation. At the same time, cells respond to virus replication by downregulating virus growth and preventing dissemination of the infection. The balance between these two mechanisms determines the outcome of infection at the cellular and organismal levels. In this report, we demonstrate that a viral nonstructural protein, nsP2, is a significant regulator of Sindbis virus-host cell interactions. This protein not only is a component of the replicative enzyme complex required for replication and transcription of viral RNAs but also plays a role in suppressing the antiviral response in Sindbis virus-infected cells. nsP2 most likely acts by decreasing interferon (IFN) production and minimizing virus visibility. Infection of murine cells with Sindbis virus expressing a mutant nsP2 leads to higher levels of IFN secretion and the activation of 170 cellular genes that are induced by IFN and/or virus replication. Secreted IFN protects naive cells against Sindbis virus infection and also stops viral replication in productively infected cells. Mutations in nsP2 can also attenuate Sindbis virus cytopathogenicity. Such mutants can persist in mammalian cells with defects in the alpha/beta IFN (IFN-α/β) system or when IFN activity is neutralized by anti-IFN-α/β antibodies. These findings provide new insight into the alphavirus-host cell interaction and have implications for the development of improved alphavirus expression systems with better antigen-presenting potential.

scholarly journals 2′-5′-Oligoadenylate Synthetase-Like Protein Inhibits Respiratory Syncytial Virus Replication and Is Targeted by the Viral Nonstructural Protein 1

2015 ◽  
Vol 89 (19) ◽  
pp. 10115-10119 ◽  
Author(s):  
Jayeeta Dhar ◽  
Rolando A. Cuevas ◽  
Ramansu Goswami ◽  
Jianzhong Zhu ◽  
Saumendra N. Sarkar ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Respiratory Syncytial Virus ◽  
Virus Replication ◽  
Nonstructural Protein ◽  
Oligoadenylate Synthetase ◽  
Antiviral Protein ◽  
Virus Growth ◽  
Nonstructural Protein 1 ◽  
Inhibitory Activities ◽  
Syncytial Virus

2′-5′-Oligoadenylate synthetase-like protein (OASL) is an interferon-inducible antiviral protein. Here we describe differential inhibitory activities of human OASL and the two mouse OASL homologs against respiratory syncytial virus (RSV) replication. Interestingly, nonstructural protein 1 (NS1) of RSV promoted proteasome-dependent degradation of specific OASL isoforms. We conclude that OASL acts as a cellular antiviral protein and that RSV NS1 suppresses this function to evade cellular innate immunity and allow virus growth.

scholarly journals Roles of the Endogenous Lunapark Protein during Flavivirus Replication

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1198
Author(s):  
Pham-Tue-Hung Tran ◽  
Naveed Asghar ◽  
Magnus Johansson ◽  
Wessam Melik
Keyword(s):  
Virus Replication ◽  
Nonstructural Protein ◽  
Host Factors ◽  
Membrane Remodeling ◽  
Biochemical Assays ◽  
Langat Virus ◽  
Underlying Mechanisms ◽  
Flavivirus Infection ◽  
Curved Membrane ◽  
High Resolution Microscopy

The endoplasmic reticulum (ER) of eukaryotic cells is a dynamic organelle, which undergoes continuous remodeling. At the three-way tubular junctions of the ER, the lunapark (LNP) protein acts as a membrane remodeling factor to stabilize these highly curved membrane junctions. In addition, during flavivirus infection, the ER membrane is invaginated to form vesicles (Ve) for virus replication. Thus, LNP may have roles in the generation or maintenance of the Ve during flavivirus infection. In this study, our aim was to characterize the functions of LNP during flavivirus infection and investigate the underlying mechanisms of these functions. To specifically study virus replication, we generated cell lines expressing replicons of West Nile virus (Kunjin strain) or Langat virus. By using these replicon platforms and electron microscopy, we showed that depletion of LNP resulted in reduced virus replication, which is due to its role in the generation of the Ve. By using biochemical assays and high-resolution microscopy, we found that LNP is recruited to the Ve and the protein interacts with the nonstructural protein (NS) 4B. Therefore, these data shed new light on the interactions between flavivirus and host factors during viral replication.

Sign in / Sign up

Export Citation Format

Share Document