scholarly journals Direct and Indirect Effects on Viral Translation and RNA Replication Are Required for AUF1 Restriction of Enterovirus Infections in Human Cells

mBio ◽  
2018 ◽  
Vol 9 (5) ◽  
Author(s):  
Wendy Ullmer ◽  
Bert L. Semler
Keyword(s):  
Mrna Decay ◽  
Coxsackievirus B3 ◽  
Human Cells ◽  
Human Rhinovirus ◽  
Host Cells ◽  
Paralytic Poliomyelitis ◽  
Common Mechanism ◽  
Restriction Factor ◽  
Nucleocytoplasmic Trafficking ◽  
Viral Translation

ABSTRACTThe cellular mRNA decay protein AUF1 acts as a restriction factor during infection by picornaviruses, including poliovirus, coxsackievirus, and human rhinovirus. AUF1 relocalizes from the nucleus to the cytoplasm during infection by these viruses due to the disruption of nucleocytoplasmic trafficking by viral proteinases. Previous studies have demonstrated that AUF1 binds to poliovirus and coxsackievirus B3 (CVB3) RNA during infection, with binding shown to occur within the internal ribosome entry site (IRES) of the 5′ noncoding region (NCR) or the 3′ NCR, respectively. Binding to different sites within the viral RNA suggests that AUF1 may negatively regulate infection by these viruses using different mechanisms. The work presented here addresses the mechanism of AUF1 inhibition of the replication of poliovirus and CVB3. We demonstrate that AUF1 knockdown in human cells results in increased viral translation, RNA synthesis, and virus production. AUF1 is shown to negatively regulate translation of a poliovirus and CVB3 IRES reporter RNA during infection but not in uninfected cells. We found that this inhibitory activity is not mediated through destabilization of viral genomic RNA; however, it does require virus-induced relocalization of AUF1 from the nucleus to the cytoplasm during the early phases of infection. Our findings suggest that AUF1 restriction of poliovirus and CVB3 replication uses a common mechanism through the viral IRES, which is distinct from the canonical role that AUF1 plays in regulated mRNA decay in uninfected host cells.IMPORTANCEPicornaviruses primarily infect the gastrointestinal or upper respiratory tracts of humans and animals and may disseminate to tissues of the central nervous system, heart, skin, liver, or pancreas. Many common human pathogens belong to thePicornaviridaefamily, which includes viruses known to cause paralytic poliomyelitis (poliovirus); myocarditis (coxsackievirus B3 [CVB3]); the common cold (human rhinovirus [HRV]); and hand, foot, and mouth disease (enterovirus 71 [EV71]), among other illnesses. There are no specific treatments for infection, and vaccines exist for only two picornaviruses: poliovirus and hepatitis A virus. Given the worldwide distribution and prevalence of picornaviruses, it is important to gain insight into the host mechanisms used to restrict infection. Other than proteins involved in the innate immune response, few host factors have been identified that restrict picornavirus replication. The work presented here seeks to define the mechanism of action for the host restriction factor AUF1 during infection by poliovirus and CVB3.

scholarly journals Divergent Requirement for a DNA Repair Enzyme during Enterovirus Infections

mBio ◽  
2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Sonia Maciejewski ◽  
Joseph H. C. Nguyen ◽  
Fernando Gómez-Herreros ◽  
Felipe Cortés-Ledesma ◽  
Keith W. Caldecott ◽  
...  
Keyword(s):  
Dna Repair ◽  
Viral Replication ◽  
Economic Impact ◽  
Coxsackievirus B3 ◽  
Replication Cycle ◽  
Human Rhinovirus ◽  
Paralytic Poliomyelitis ◽  
Protein Accumulation ◽  
Repair Enzyme ◽  
Potential Target

ABSTRACTViruses of theEnterovirusgenus of picornaviruses, including poliovirus, coxsackievirus B3 (CVB3), and human rhinovirus, commandeer the functions of host cell proteins to aid in the replication of their small viral genomic RNAs during infection. One of these host proteins is a cellular DNA repair enzyme known as 5′ tyrosyl-DNA phosphodiesterase 2 (TDP2). TDP2 was previously demonstrated to mediate the cleavage of a unique covalent linkage between a viral protein (VPg) and the 5′ end of picornavirus RNAs. Although VPg is absent from actively translating poliovirus mRNAs, the removal of VPg is not required for thein vitrotranslation and replication of the RNA. However, TDP2 appears to be excluded from replication and encapsidation sites during peak times of poliovirus infection of HeLa cells, suggesting a role for TDP2 during the viral replication cycle. Using a mouse embryonic fibroblast cell line lacking TDP2, we found that TDP2 is differentially required among enteroviruses. Our single-cycle viral growth analysis shows that CVB3 replication has a greater dependency on TDP2 than does poliovirus or human rhinovirus replication. During infection, CVB3 protein accumulation is undetectable (by Western blot analysis) in the absence of TDP2, whereas poliovirus protein accumulation is reduced but still detectable. Using an infectious CVB3 RNA with a reporter, CVB3 RNA could still be replicated in the absence of TDP2 following transfection, albeit at reduced levels. Overall, these results indicate that TDP2 potentiates viral replication during enterovirus infections of cultured cells, making TDP2 a potential target for antiviral development for picornavirus infections.IMPORTANCEPicornaviruses are one of the most prevalent groups of viruses that infect humans and livestock worldwide. These viruses include the human pathogens belonging to theEnterovirusgenus, such as poliovirus, coxsackievirus B3 (CVB3), and human rhinovirus. Diseases caused by enteroviruses pose a major problem for public health and have significant economic impact. Poliovirus can cause paralytic poliomyelitis. CVB3 can cause hand, foot, and mouth disease and myocarditis. Human rhinovirus is the causative agent of the common cold, which has a severe economic impact due to lost productivity and severe health consequences in individuals with respiratory dysfunction, such as asthma. By gaining a better understanding of the enterovirus replication cycle, antiviral drugs against enteroviruses may be developed. Here, we report that the absence of the cellular enzyme TDP2 can significantly decrease viral yields of poliovirus, CVB3, and human rhinovirus, making TDP2 a potential target for an antiviral against enterovirus infections.

scholarly journals Doratoxylon apetalum, an Indigenous Medicinal Plant from Mascarene Islands, Is a Potent Inhibitor of Zika and Dengue Virus Infection in Human Cells

2019 ◽  
Vol 20 (10) ◽  
pp. 2382 ◽  
Author(s):  
Juliano G. Haddad ◽  
Andrea Cristine Koishi ◽  
Arnaud Gaudry ◽  
Claudia Nunes Duarte dos Santos ◽  
Wildriss Viranaicken ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Medicinal Plant ◽  
Dengue Virus ◽  
Denv Infection ◽  
Antiviral Drugs ◽  
Human Cells ◽  
Host Cells ◽  
Global Public Health ◽  
Denv Serotypes ◽  
Mascarene Islands

Zika virus (ZIKV) and Dengue virus (DENV) are mosquito-borne viruses of the Flavivirus genus that could cause congenital microcephaly and hemorrhage, respectively, in humans, and thus present a risk to global public health. A preventive vaccine against ZIKV remains unavailable, and no specific antiviral drugs against ZIKV and DENV are licensed. Medicinal plants may be a source of natural antiviral drugs which mostly target viral entry. In this study, we evaluate the antiviral activity of Doratoxylum apetalum, an indigenous medicinal plant from the Mascarene Islands, against ZIKV and DENV infection. Our data indicated that D. apetalum exhibited potent antiviral activity against a contemporary epidemic strain of ZIKV and clinical isolates of four DENV serotypes at non-cytotoxic concentrations in human cells. Time-of-drug-addition assays revealed that D. apetalum extract acts on ZIKV entry by preventing the internalisation of virus particles into the host cells. Our data suggest that D. apetalum-mediated ZIKV inhibition relates to virus particle inactivation. We suggest that D. apetalum could be a promising natural source for the development of potential antivirals against medically important flaviviruses.

scholarly journals Novel [(biphenyloxy)propyl]isoxazole derivatives for inhibition of human rhinovirus 2 and coxsackievirus B3 replication

2005 ◽  
Vol 55 (4) ◽  
pp. 483-488 ◽  
Author(s):  
Vadim A. Makarov ◽  
Olga B. Riabova ◽  
Vladimir G. Granik ◽  
Peter Wutzler ◽  
Michaela Schmidtke
Keyword(s):  
Coxsackievirus B3 ◽  
Human Rhinovirus ◽  
Isoxazole Derivatives

OmpD but not OmpC is involved in adherence ofSalmonella entericaserovar Typhimurium to human cells

2004 ◽  
Vol 50 (9) ◽  
pp. 719-727 ◽  
Author(s):  
Bochiwe Hara-Kaonga ◽  
Thomas G Pistole
Keyword(s):  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Human Cells ◽  
Host Cells ◽  
Intestinal Epithelial ◽  
Wild Type ◽  
Human Macrophages ◽  
Significant Difference ◽  
Serovar Typhimurium

Conflicting reports exist regarding the role of porins OmpC and OmpD in infections due to Salmonella enterica serovar Typhimurium. This study investigated the role of these porins in bacterial adherence to human macrophages and intestinal epithelial cells. ompC and ompD mutant strains were created by transposon mutagenesis using P22-mediated transduction of Tn10 and Tn5 insertions, respectively, into wild-type strain 14028. Fluorescein-labeled wild-type and mutant bacteria were incubated with host cells at various bacteria to cell ratios for 1 h at 37 °C and analyzed by flow cytometry. The mean fluorescence intensity of cells with associated wild-type and mutant bacteria was used to estimate the number of bacteria bound per host cell. Adherence was also measured by fluorescence microscopy. Neither assay showed a significant difference in binding of the ompC mutant and wild-type strains to the human cells. In contrast, the ompD mutant exhibited lowered binding to both cell types. Our findings suggest that OmpD but not OmpC is involved in the recognition of Salmonella serovar Typhimurium by human macrophages and intestinal epithelial cells.Key words: Salmonella, adherence, porins, intestinal epithelial cells, macrophage.

scholarly journals Differential restriction patterns of mRNA decay factor AUF1 during picornavirus infections

2014 ◽  
Vol 95 (7) ◽  
pp. 1488-1492 ◽  
Author(s):  
Andrea L. Cathcart ◽  
Bert L. Semler
Keyword(s):  
Mrna Decay ◽  
Rna Binding ◽  
Rna Binding Protein ◽  
Encephalomyocarditis Virus ◽  
Restriction Factor ◽  
Host Proteins ◽  
Specific Host ◽  
Decay Factor ◽  
Cellular Environment ◽  
Binding Factor

During infection by picornaviruses, the cellular environment is modified to favour virus replication. This includes the modification of specific host proteins, including the recently discovered viral proteinase cleavage of mRNA decay factor AU-rich binding factor 1 (AUF1). This cellular RNA-binding protein was shown previously to act as a restriction factor during poliovirus, rhinovirus and coxsackievirus infection. During infection by these viruses, AUF1 relocalizes to the cytoplasm and is cleaved by the viral 3C/3CD proteinase. In this study, we demonstrated that replication of encephalomyocarditis virus (EMCV), a picornavirus belonging to the genus Cardiovirus, is AUF1 independent. During EMCV infection, AUF1 relocalized to the cytoplasm; however, unlike what is seen during enterovirus infections, AUF1 was not cleaved to detectable levels, even at late times after infection. This suggests that AUF1 does not act broadly as an inhibitor of picornavirus infections but may instead act as a selective restriction factor targeting members of the genus Enterovirus.

scholarly journals Cytoplasmic foci are sites of mRNA decay in human cells

2004 ◽  
Vol 165 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Nicolas Cougot ◽  
Sylvie Babajko ◽  
Bertrand Séraphin
Keyword(s):  
Mrna Decay ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Human Cells ◽  
Eukaryotic Cells ◽  
Mrna Turnover ◽  
Expression Control ◽  
Gene Expression Control ◽  
Cytoplasmic Structures

Understanding gene expression control requires defining the molecular and cellular basis of mRNA turnover. We have previously shown that the human decapping factors hDcp2 and hDcp1a are concentrated in specific cytoplasmic structures. Here, we show that hCcr4, hDcp1b, hLsm, and rck/p54 proteins related to 5′–3′ mRNA decay also localize to these structures, whereas DcpS, which is involved in cap nucleotide catabolism, is nuclear. Functional analysis using fluorescence resonance energy transfer revealed that hDcp1a and hDcp2 interact in vivo in these structures that were shown to differ from the previously described stress granules. Our data indicate that these new structures are dynamic, as they disappear when mRNA breakdown is abolished by treatment with inhibitors. Accumulation of poly(A)+ RNA in these structures, after RNAi-mediated inactivation of the Xrn1 exonuclease, demonstrates that they represent active mRNA decay sites. The occurrence of 5′–3′ mRNA decay in specific subcellular locations in human cells suggests that the cytoplasm of eukaryotic cells may be more organized than previously anticipated.

scholarly journals Quantifying mRNA targeting to P-bodies in living human cells reveals their dual role in mRNA decay and storage

2014 ◽  
Vol 127 (20) ◽  
pp. 4443-4456 ◽  
Author(s):  
Adva Aizer ◽  
Alon Kalo ◽  
Pinhas Kafri ◽  
Amit Shraga ◽  
Rakefet Ben-Yishay ◽  
...  
Keyword(s):  
Mrna Decay ◽  
Dual Role ◽  
Human Cells ◽  
P Bodies ◽  
And Storage ◽  
Mrna Targeting

scholarly journals Zinc-finger antiviral protein (ZAP) is a restriction factor for replication of modified vaccinia virus Ankara (MVA) in human cells

2020 ◽  
Vol 16 (8) ◽  
pp. e1008845
Author(s):  
Chen Peng ◽  
Linda S. Wyatt ◽  
Shira G. Glushakow-Smith ◽  
Madhu Lal-Nag ◽  
Andrea S. Weisberg ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Zinc Finger ◽  
Human Cells ◽  
Restriction Factor ◽  
Antiviral Protein ◽  
Modified Vaccinia Virus Ankara

scholarly journals Highly Divergent Lentiviral Tat Proteins Activate Viral Gene Expression by a Common Mechanism

1999 ◽  
Vol 19 (7) ◽  
pp. 4592-4599 ◽  
Author(s):  
Paul D. Bieniasz ◽  
Therese A. Grdina ◽  
Hal P. Bogerd ◽  
Bryan R. Cullen
Keyword(s):  
Gene Expression ◽  
Protein Complex ◽  
Equine Infectious Anemia Virus ◽  
Viral Gene Expression ◽  
Human Cells ◽  
Common Mechanism ◽  
Viral Gene ◽  
Target Element ◽  
Anemia Virus ◽  
Hiv 1

ABSTRACT The human immunodeficiency virus type 1 (HIV-1) Tat protein (hTat) activates transcription initiated at the viral long terminal repeat (LTR) promoter by a unique mechanism requiring recruitment of the human cyclin T1 (hCycT1) cofactor to the viral TAR RNA target element. While activation of equine infectious anemia virus (EIAV) gene expression by the EIAV Tat (eTat) protein appears similar in that the target element is a promoter proximal RNA, eTat shows little sequence homology to hTat, does not activate the HIV-1 LTR, and is not active in human cells that effectively support hTat function. To address whether eTat and hTat utilize similar or distinct mechanisms of action, we have cloned the equine homolog of hCycT1 (eCycT1) and examined whether it is required to mediate eTat function. Here, we report that expression of eCycT1 in human cells fully rescues eTat function and that eCycT1 and eTat form a protein complex that specifically binds to the EIAV, but not the HIV-1, TAR element. While hCycT1 is also shown to interact with eTat, the lack of eTat function in human cells is explained by the failure of the resultant protein complex to bind to EIAV TAR. Critical sequences in eCycT1 required to support eTat function are located very close to the amino terminus, i.e., distal to the HIV-1 Tat-TAR interaction motif previously identified in the hCycT1 protein. Together, these data provide a molecular explanation for the species tropism displayed by eTat and demonstrate that highly divergent lentiviral Tat proteins activate transcription from their cognate LTR promoters by essentially identical mechanisms.

scholarly journals Inhibition of Avian Influenza A Virus Replication in Human Cells by Host Restriction Factor TUFM Is Correlated with Autophagy

mBio ◽  
2017 ◽  
Vol 8 (3) ◽  
Author(s):  
Shu-Ming Kuo ◽  
Chi-Jene Chen ◽  
Shih-Cheng Chang ◽  
Tzu-Jou Liu ◽  
Yi-Hsiang Chen ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Virus Replication ◽  
Influenza A ◽  
Inhibitory Effect ◽  
Human Cells ◽  
Restriction Factor ◽  
Influenza A Viruses ◽  
Host Restriction ◽  
Host Restriction Factor

ABSTRACT Avian influenza A viruses generally do not replicate efficiently in human cells, but substitution of glutamic acid (Glu, E) for lysine (Lys, K) at residue 627 of avian influenza virus polymerase basic protein 2 (PB2) can serve to overcome host restriction and facilitate human infectivity. Although PB2 residue 627 is regarded as a species-specific signature of influenza A viruses, host restriction factors associated with PB2627E have yet to be fully investigated. We conducted immunoprecipitation, followed by differential proteomic analysis, to identify proteins associating with PB2627K (human signature) and PB2627E (avian signature) of influenza A/WSN/1933(H1N1) virus, and the results indicated that Tu elongation factor, mitochondrial (TUFM), had a higher binding affinity for PB2627E than PB2627K in transfected human cells. Stronger binding of TUFM to avian-signature PB2590G/591Q and PB2627E in the 2009 swine-origin pandemic H1N1 and 2013 avian-origin H7N9 influenza A viruses was similarly observed. Viruses carrying avian-signature PB2627E demonstrated increased replication in TUFM-deficient cells, but viral replication decreased in cells overexpressing TUFM. Interestingly, the presence of TUFM specifically inhibited the replication of PB2627E viruses, but not PB2627K viruses. In addition, enhanced levels of interaction between TUFM and PB2627E were noted in the mitochondrial fraction of infected cells. Furthermore, TUFM-dependent autophagy was reduced in TUFM-deficient cells infected with PB2627E virus; however, autophagy remained consistent in PB2627K virus-infected cells. The results suggest that TUFM acts as a host restriction factor that impedes avian-signature influenza A virus replication in human cells in a manner that correlates with autophagy. IMPORTANCE An understanding of the mechanisms that influenza A viruses utilize to shift host tropism and the identification of host restriction factors that can limit infection are both critical to the prevention and control of emerging viruses that cross species barriers to target new hosts. Using a proteomic approach, we revealed a novel role for TUFM as a host restriction factor that exerts an inhibitory effect on avian-signature PB2627E influenza virus propagation in human cells. We further found that increased TUFM-dependent autophagy correlates with the inhibitory effect on avian-signature influenza virus replication and may serve as a key intrinsic mechanism to restrict avian influenza virus infection in humans. These findings provide new insight regarding the TUFM mitochondrial protein and may have important implications for the development of novel antiviral strategies. IMPORTANCE An understanding of the mechanisms that influenza A viruses utilize to shift host tropism and the identification of host restriction factors that can limit infection are both critical to the prevention and control of emerging viruses that cross species barriers to target new hosts. Using a proteomic approach, we revealed a novel role for TUFM as a host restriction factor that exerts an inhibitory effect on avian-signature PB2627E influenza virus propagation in human cells. We further found that increased TUFM-dependent autophagy correlates with the inhibitory effect on avian-signature influenza virus replication and may serve as a key intrinsic mechanism to restrict avian influenza virus infection in humans. These findings provide new insight regarding the TUFM mitochondrial protein and may have important implications for the development of novel antiviral strategies.

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