scholarly journals Expression profile of the PIWI mRNAs protein family in human cells experimentally infected with Dengue Virus 4

2021 ◽  
Vol 10 (3) ◽  
pp. e32010313371
Author(s):  
Walter Félix Franco Neto ◽  
Murilo Tavares Amorim ◽  
Karla Fabiane Lopes de Melo ◽  
Gustavo Moraes Holanda ◽  
Jardel Fábio Lopes Ferreira ◽  
...  

Objective: Evaluate the messenger RNAs (mRNA) PIWI proteins expression during infection with VDEN 4 in human hepatocyte cells. Materials and Methods: VDEN4 strain H778494 (JQ513335) was used, which was stored in Aedes albopictus cell culture (Clone C6 / 36) at the Arbovirology and Hemorrhagic Fevers section of the Evandro Chagas Institute. The techniques of cell cultures, stock (C6/36), inoculation, extraction, viral load quantification, RTqPCR and statistical analyzes were performed at the Viral Biogenesis Laboratory. Results: According to the results obtained, two cells (HepG2 and Huh7.5) demonstrated a higher level of viral replication at 72 hours post infection (hpi). The PIWI 2 target alter its mRNA expression during VDEN4 infection. The PIWI 4 target expression, was observed an altered expression in the infected cells. Thus, it was found that they are in different poles, while the viral load in the first three days showed high expression. The expression of mRNA was low in relation to the normal rate given by the uninfected cells. Conclusion: In our findings, it was observed that PIWI2 and 4 proteins have an inverse relationship to the viral infection process by VDEN4, when there is an increase in viral replication, these two proteins end up having a significant reduction in their expression. Probably, this reduction of expression is involved with the biogenesis process of apoptosis-regulating microRNAs.

2022 ◽  
Vol 23 (2) ◽  
pp. 875
Author(s):  
Pontus Öhlund ◽  
Nicolas Delhomme ◽  
Juliette Hayer ◽  
Jenny C. Hesson ◽  
Anne-Lie Blomström

Understanding the flavivirus infection process in mosquito hosts is important and fundamental in the search for novel control strategies that target the mosquitoes’ ability to carry and transmit pathogenic arboviruses. A group of viruses known as insect-specific viruses (ISVs) has been shown to interfere with the infection and replication of a secondary arbovirus infection in mosquitoes and mosquito-derived cell lines. However, the molecular mechanisms behind this interference are unknown. Therefore, in the present study, we infected the Aedes albopictus cell line U4.4 with either the West Nile virus (WNV), the insect-specific Lammi virus (LamV) or an infection scheme whereby cells were pre-infected with LamV 24 h prior to WNV challenge. The qPCR analysis showed that the dual-infected U4.4 cells had a reduced number of WNV RNA copies compared to WNV-only infected cells. The transcriptome profiles of the different infection groups showed a variety of genes with altered expression. WNV-infected cells had an up-regulation of a broad range of immune-related genes, while in LamV-infected cells, many genes related to stress, such as different heat-shock proteins, were up-regulated. The transcriptome profile of the dual-infected cells was a mix of up- and down-regulated genes triggered by both viruses. Furthermore, we observed an up-regulation of signal peptidase complex (SPC) proteins in all infection groups. These SPC proteins have shown importance for flavivirus assembly and secretion and could be potential targets for gene modification in strategies for the interruption of flavivirus transmission by mosquitoes.


2019 ◽  
Author(s):  
Caroline Manet ◽  
Etienne Simon-Lorière ◽  
Grégory Jouvion ◽  
David Hardy ◽  
Matthieu Prot ◽  
...  

ABSTRACTThe explosive spread of Zika virus (ZIKV) has been associated with major variations in severe disease and congenital afflictions among infected populations, suggesting an influence of host genes. We investigated how genome-wide variants could impact susceptibility to ZIKV infection in mice. We first describe that the susceptibility of Ifnar1 knockout mice is largely influenced by their genetic background. We then show that the broad genetic diversity of Collaborative Cross mice, which receptor to type I interferon (IFNAR) was blocked by anti-IFNAR antibody, expressed phenotypes ranging from complete resistance to severe symptoms and death with large variations in the peak and rate of decrease of plasma viral load, in brain viral load, in brain histopathology and in viral replication rate in infected cells. Differences of susceptibility between CC strains were correlated between Zika, Dengue and West Nile viruses. We identified highly susceptible and resistant mouse strains as new models to investigate the mechanisms of human ZIKV disease and other flavivirus infections. Genetic analyses revealed that phenotypic variations are driven by multiple genes with small effects, reflecting the complexity of ZIKV disease susceptibility in human population. Notably, our results rule out a role of the Oas1b gene in the susceptibility to ZIKV. Altogether, this study emphasizes the role of host genes in the pathogeny of ZIKV infection and lays the foundation for further genetic and mechanistic studies.IMPORTANCEIn recent outbreaks, ZIKV has infected millions of people and induced rare but potentially severe complications, including Guillain-Barré syndrome and encephalitis in adults. While several viral sequence variants were proposed to enhance the pathogenicity of ZIKV, the influence of host genetic variants in the clinical heterogeneity remains mostly unexplored. We have addressed this question using a mouse panel which models the genetic diversity of human population and a ZIKV strain from a recent clinical isolate. Through a combination of in vitro and in vivo approaches, we demonstrate that multiple host genetic variants determine viral replication in infected cells, and clinical severity, kinetics of blood viral load and brain pathology in mice. We describe new mouse models expressing high susceptibility or resistance to ZIKV and to other flaviviruses. These models will facilitate the identification and mechanistic characterization of host genes that influence ZIKV pathogenesis.


2019 ◽  
Author(s):  
Veronika Bernhauerová ◽  
Veronica V. Rezelj ◽  
Laura I. Levi ◽  
Marco Vignuzzi

AbstractChikungunya and Zika viruses are arthropod-borne viruses that pose significant threat to public health. Experimental data show that duringin vitroinfection both viruses exhibit qualitatively distinct replication cycle kinetics. Chikungunya viral load rapidly accumulates within the first several hours post infection whereas Zika virus begins to increase at much later times. We sought to characterize these qualitatively distinctin vitrokinetics of chikungunya and Zika viruses by fitting a family of mathematical models to time course viral load datasets. We demonstrate that the standard viral kinetic model, which considers that new infections result only from free virus penetrating susceptible cells, does not fit experimental data as well as a model in which the number of virus-infected cells is the primary determinant of infection rate. We provide biologically meaningful quantifications of the main viral kinetic parameters and show that our results support cell-to-cell or localized transmission as a significant contributor to viral infection with chikungunya and Zika viruses.ImportanceMathematical modeling has become a useful tool to tease out information about virus-host interactions and thus complements experimental work in characterizing and quantifying processes within viral replication cycle. Importantly, mathematical models can fill in incomplete data sets and identify key parameters of infection, provided the appropriate model is used. Thein vitrotime course dynamics of mosquito transmitted viruses, such as chikungunya and Zika, have not been studied by mathematical modeling and thus limits our knowledge about quantitative description of the individual determinants of viral replication cycle. This study employs dynamical modeling framework to show that the rate at which cells become virus-infected is proportional to the number or virus-infected cells rather than free extracellular virus in the milieu, a widely accepted assumption in models of viral infections. Using the refined mathematical model in combination with viral load data, we provide quantification of the main drivers of chikungunya and Zikain vitrokinetics. Together, our results bring quantitative understanding of the basic components of chikungunya and Zika virus dynamics.


2009 ◽  
Vol 54 (3) ◽  
pp. 1047-1054 ◽  
Author(s):  
Daniel A. Donahue ◽  
Richard D. Sloan ◽  
Björn D. Kuhl ◽  
Tamara Bar-Magen ◽  
Susan M. Schader ◽  
...  

ABSTRACT Recent clinical trials have shown that the use of the HIV-1 integrase (IN) inhibitor raltegravir (RAL) results in drops in the viral load that are more rapid than those achieved by use of the reverse transcriptase (RT) inhibitor efavirenz. Previously, mathematical modeling of viral load decay that takes into account the stage of viral replication targeted by a drug has yielded data that closely approximate the clinical trial results. This model predicts greater inhibition of viral replication by drugs that act later in the viral replication cycle. In the present study, we have added drugs that target entry, reverse transcription, integration, or proteolytic processing to acutely infected cells and have shown modest viral inhibition by entry inhibitors, intermediate levels of inhibition by RT and IN inhibitors, and high levels of inhibition by protease inhibitors relative to the levels of growth for the no-drug controls. When dual or triple combinations of these drugs were added to acutely infected cells, we found that the levels of inhibition achieved by any given combination were comparable to those achieved by the latest-acting drug in the combination. In single-round infections in which the kinetics of reverse transcription and integration had been determined by quantitative PCR, addition of IN inhibitors at various times postinfection resulted in levels of inhibition equal to or greater than those achieved by addition of RT inhibitors. Collectively, our data provide in vitro evidence of the stage-dependent inhibition of HIV-1 by clinically relevant drugs. We discuss how stage-dependent inhibition helps to explain the unique viral load decay dynamics observed clinically with RAL.


2019 ◽  
Vol 94 (3) ◽  
Author(s):  
Caroline Manet ◽  
Etienne Simon-Lorière ◽  
Grégory Jouvion ◽  
David Hardy ◽  
Matthieu Prot ◽  
...  

ABSTRACT The explosive spread of Zika virus (ZIKV) has been associated with major variations in severe disease and congenital afflictions among infected populations, suggesting an influence of host genes. We investigated how genome-wide variants could impact susceptibility to ZIKV infection in mice. We first describe that the susceptibility of Ifnar1-knockout mice is largely influenced by their genetic background. We then show that Collaborative Cross (CC) mice, which exhibit a broad genetic diversity, in which the type I interferon receptor (IFNAR) was blocked by an anti-IFNAR antibody expressed phenotypes ranging from complete resistance to severe symptoms and death, with large variations in the peak and the rate of decrease in the plasma viral load, in the brain viral load, in brain histopathology, and in the viral replication rate in infected cells. The differences in susceptibility to ZIKV between CC strains correlated with the differences in susceptibility to dengue and West Nile viruses between the strains. We identified highly susceptible and resistant mouse strains as new models to investigate the mechanisms of human ZIKV disease and other flavivirus infections. Genetic analyses revealed that phenotypic variations are driven by multiple genes with small effects, reflecting the complexity of ZIKV disease susceptibility in the human population. Notably, our results rule out the possibility of a role of the Oas1b gene in the susceptibility to ZIKV. Altogether, the findings of this study emphasize the role of host genes in the pathogeny of ZIKV infection and lay the foundation for further genetic and mechanistic studies. IMPORTANCE In recent outbreaks, ZIKV has infected millions of people and induced rare but potentially severe complications, including Guillain-Barré syndrome and encephalitis in adults. While several viral sequence variants were proposed to enhance the pathogenicity of ZIKV, the influence of host genetic variants in mediating the clinical heterogeneity remains mostly unexplored. We addressed this question using a mouse panel which models the genetic diversity of the human population and a ZIKV strain from a recent clinical isolate. Through a combination of in vitro and in vivo approaches, we demonstrate that multiple host genetic variants determine viral replication in infected cells and the clinical severity, the kinetics of blood viral load, and brain pathology in mice. We describe new mouse models expressing high degrees of susceptibility or resistance to ZIKV and to other flaviviruses. These models will facilitate the identification and mechanistic characterization of host genes that influence ZIKV pathogenesis.


1998 ◽  
Vol 72 (9) ◽  
pp. 7263-7269 ◽  
Author(s):  
J. Lindsay Oaks ◽  
Travis C. McGuire ◽  
Catherine Ulibarri ◽  
Timothy B. Crawford

ABSTRACT The equine infectious anemia virus (EIAV) often results in lifelong subclinical infection following early episodes of clinical disease. To identify the cellular reservoirs of EIAV during subclinical infection, horses were infected with EIAV and allowed to develop subclinical infections. Horses with acute disease served as a basis for comparison. The tissue distribution, replication status, location of infected cells, and viral load were characterized by PCR for proviral DNA and reverse transcriptase PCR for viral RNA, in situ hybridization, and in situ PCR. Proviral DNA was widespread in tissues regardless of disease status. Viral gag and env RNAs were also detected in tissues of all horses regardless of disease status. Plasma viral RNA (viremia) could be detected in some, but not all, horses with subclinical infections. In situ assays determined that a primary cellular reservoir and site of viral replication during subclinical infection is the macrophage. During subclinical infection, viral load was decreased 4- to 733-fold and there was decreased viral RNA expression within infected cells. These data indicate that viral replication continues at all times, even in horses that are clinically quiescent. Moreover, restricted viral replication at the cellular level is associated with clinical remission.


Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 244
Author(s):  
Laura Albentosa-González ◽  
Rosario Sabariegos ◽  
Armando Arias ◽  
Pilar Clemente-Casares ◽  
Antonio Mas

Usutu virus (USUV) is a flavivirus that mainly infects wild birds through the bite of Culex mosquitoes. Recent outbreaks have been associated with an increased number of cases in humans. Despite being a growing source of public health concerns, there is yet insufficient data on the virus or host cell targets for infection control. In this work we have investigated whether the cellular kinase Akt and USUV polymerase NS5 interact and co-localize in a cell. To this aim, we performed co-immunoprecipitation (Co-IP) assays, followed by confocal microscopy analyses. We further tested whether NS5 is a phosphorylation substrate of Akt in vitro. Finally, to examine its role in viral replication, we chemically silenced Akt with three inhibitors (MK-2206, honokiol and ipatasertib). We found that both proteins are localized (confocal) and pulled down (Co-IP) together when expressed in different cell lines, supporting the fact that they are interacting partners. This possibility was further sustained by data showing that NS5 is phosphorylated by Akt. Treatment of USUV-infected cells with Akt-specific inhibitors led to decreases in virus titers (>10-fold). Our results suggest an important role for Akt in virus replication and stimulate further investigations to examine the PI3K/Akt/mTOR pathway as an antiviral target.


Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 753
Author(s):  
Sneha Singh ◽  
Onkar B. Sawant ◽  
Shahzad I. Mian ◽  
Ashok Kumar

Several RNA viruses, including SARS-CoV-2, can infect or use the eye as an entry portal to cause ocular or systemic diseases. Povidone-Iodine (PVP-I) is routinely used during ocular surgeries and eye banking as a cost-effective disinfectant due to its broad-spectrum antimicrobial activity, including against viruses. However, whether PVP-I can exert antiviral activities in virus-infected cells remains elusive. In this study, using Zika (ZIKV) and Chikungunya (CHIKV) virus infection of human corneal and retinal pigment epithelial cells, we report antiviral mechanisms of PVP-I. Our data showed that PVP-I, even at the lowest concentration (0.01%), drastically reduced viral replication in corneal and retinal cells without causing cellular toxicity. Antiviral effects of PVP-I against ZIKV and CHIKV were mediated by direct viral inactivation, thus attenuating the ability of the virus to infect host cells. Moreover, one-minute PVP-I exposure of infected ocular cells drastically reduced viral replication and the production of infectious progeny virions. Furthermore, viral-induced (CHIKV) expression of inflammatory genes (TNF-α, IL-6, IL-8, and IL1β) were markedly reduced in PVP-I treated corneal epithelial cells. Together, our results demonstrate potent antiviral effects of PVP-I against ZIKV and CHIKV infection of ocular cells. Thus, a low dose of PVP-I can be used during tissue harvesting for corneal transplants to prevent potential transmission of RNA viruses via infected cells.


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