scholarly journals Properties of Oligomeric Interaction of the Cytomegalovirus Core Nuclear Egress Complex (NEC) and Its Sensitivity to an NEC Inhibitory Small Molecule

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 462 ◽  
Author(s):  
Jintawee Kicuntod ◽  
Sewar Alkhashrom ◽  
Sigrun Häge ◽  
Benedikt Diewald ◽  
Regina Müller ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Regulatory Element ◽  
Antiviral Drug ◽  
Confocal Imaging ◽  
Fusion Construct ◽  
Functional Conservation ◽  
Nuclear Egress ◽  
Inhibitory Molecule ◽  
Helical Groove

Herpesviral nuclear egress is a regulated process shared by all family members, ensuring the efficient cytoplasmic release of viral capsids. In the case of human cytomegalovirus (HCMV), the core of the nuclear egress complex (NEC) consists of the pUL50-pUL53 heterodimer that builds hexameric lattices for capsid binding and multicomponent interaction, including NEC-associated host factors. A characteristic feature of NEC interaction is the N-terminal hook structure of pUL53 that binds to an alpha-helical groove of pUL50, thus termed as hook-into-groove interaction. This central regulatory element is essential for viral replication and shows structural–functional conservation, which has been postulated as a next-generation target of antiviral strategies. However, a solid validation of this concept has been missing. In the present study, we focused on the properties of oligomeric HCMV core NEC interaction and the antiviral activity of specifically targeted prototype inhibitors. Our data suggest the following: (i) transiently expressed, variably tagged versions of HCMV NEC proteins exert hook-into-groove complexes, putatively in oligomeric assemblies that are distinguishable from heterodimers, as shown by in vitro assembly and coimmunoprecipitation approaches; (ii) this postulated oligomeric binding pattern was further supported by the use of a pUL50::pUL53 fusion construct also showing a pronounced multi-interaction potency; (iii) using confocal imaging cellular NEC-associated proteins were found partly colocalized with the tagged core NECs; (iv) a small inhibitory molecule, recently identified by an in vitro binding inhibition assay, was likewise active in blocking pUL50–pUL53 oligomeric assembly and in exerting antiviral activity in HCMV-infected fibroblasts. In summary, the findings refine the previous concept of HCMV core NEC formation and nominate this drug-accessible complex as a validated antiviral drug target.

scholarly journals Antiviral Activity of Favipiravir (T-705) against a Broad Range of ParamyxovirusesIn Vitroand against Human Metapneumovirus in Hamsters

2016 ◽  
Vol 60 (8) ◽  
pp. 4620-4629 ◽  
Author(s):  
D. Jochmans ◽  
S. van Nieuwkoop ◽  
S. L. Smits ◽  
J. Neyts ◽  
R. A. M. Fouchier ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Measles Virus ◽  
Rna Virus ◽  
Antiviral Drug ◽  
Specific Effect ◽  
Human Metapneumovirus ◽  
Drug Candidate ◽  
Emerging Viruses ◽  
Syncytial Virus

ABSTRACTThe clinical impact of infections with respiratory viruses belonging to the familyParamyxoviridaeargues for the development of antiviral therapies with broad-spectrum activity. Favipiravir (T-705) has demonstrated potent antiviral activity against multiple RNA virus families and is presently in clinical evaluation for the treatment of influenza. Here we demonstratein vitroactivity of T-705 against the paramyxoviruses human metapneumovirus (HMPV), respiratory syncytial virus, human parainfluenza virus, measles virus, Newcastle disease virus, and avian metapneumovirus. In addition, we demonstrate activity against HMPV in hamsters. T-705 treatment inhibited replication of all paramyxoviruses testedin vitro, with 90% effective concentration (EC90) values of 8 to 40 μM. Treatment of HMPV-challenged hamsters with T-705 at 200 mg/kg of body weight/day resulted in 100% protection from infection of the lungs. In all treated and challenged animals, viral RNA remained detectable in the respiratory tract. The observation that T-705 treatment had a significant effect on infectious viral titers, with a limited effect on viral genome titers, is in agreement with its proposed mode of action of viral mutagenesis. However, next-generation sequencing of viral genomes isolated from treated and challenged hamsters did not reveal (hyper)mutation. Polymerase activity assays revealed a specific effect of T-705 on the activity of the HMPV polymerase. With the reported antiviral activity of T-705 against a broad range of RNA virus families, this small molecule is a promising broad-range antiviral drug candidate for limiting the viral burden of paramyxoviruses and for evaluation for treatment of infections with (re)emerging viruses, such as the henipaviruses.

scholarly journals Dual Inhibition of Human Rhinovirus 2A and 3C Proteases by Homophthalimides

1998 ◽  
Vol 42 (4) ◽  
pp. 916-920 ◽  
Author(s):  
Q. May Wang ◽  
Robert B. Johnson ◽  
Louis N. Jungheim ◽  
Jeffrey D. Cohen ◽  
Elcira C. Villarreal
Keyword(s):  
Antiviral Activity ◽  
Viral Replication ◽  
Enzyme Inhibitor ◽  
Antiviral Drug ◽  
3C Protease ◽  
Dependent Inhibition ◽  
Dual Inhibition ◽  
2A Protease

ABSTRACT The 2A and 3C proteases encoded by human rhinoviruses (HRVs) are attractive targets for antiviral drug development due to their important roles in viral replication. Homophthalimides were originally identified as inhibitors of rhinovirus 3C protease through our screening effort. Previous studies have indicated that the antiviral activity of certain homophthalimides exceeded their in vitro inhibitory activity against the viral 3C protease, suggesting that an additional mechanism might be involved. Reported here is the identification of homophthalimides as potent inhibitors for another rhinovirus protease, designated 2A. Several homophthalimides exhibit time-dependent inhibition of the 2A protease in the low-micromolar range, and enzyme-inhibitor complexes were identified by mass spectrometry. Compound LY343814, one of the most potent inhibitors against HRV14 2A protease, had an antiviral 50% inhibitory concentration of 4.2 μM in the cell-based assay. Our data reveal that homophthalimides are not only 3C but also 2A protease inhibitors in vitro, implying that the antiviral activity associated with these compounds might result from inactivation of both 2A and 3C proteases in vivo. Since the processing of the viral polyprotein is hierarchical, dual inhibition of the two enzymes may result in cooperative inhibition of viral replication. On the basis of the current understanding of their enzyme inhibitory mechanism, homophthalimides, as a group of novel nonpeptidic antirhinovirus agents, merit further structure-action relationship studies.

scholarly journals Patterns of Autologous and Nonautologous Interactions between Core Nuclear Egress Complex (NEC) Proteins of α-, β- and γ-Herpesviruses

Viruses ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 303 ◽  
Author(s):  
Sigrun Häge ◽  
Eric Sonntag ◽  
Eva Maria Borst ◽  
Pierre Tannig ◽  
Lisa Seyler ◽  
...  
Keyword(s):  
Confocal Imaging ◽  
Murine Cytomegalovirus ◽  
Varicella Zoster ◽  
Barr Virus ◽  
Functional Complementarity ◽  
Nuclear Egress ◽  
Murine Fibroblasts ◽  
Epstein Barr

Nuclear egress is a regulated process shared by α-, β- and γ-herpesviruses. The core nuclear egress complex (NEC) is composed of the membrane-anchored protein homologs of human cytomegalovirus (HCMV) pUL50, murine cytomegalovirus (MCMV) pM50, Epstein–Barr virus (EBV) BFRF1 or varicella zoster virus (VZV) Orf24, which interact with the autologous NEC partners pUL53, pM53, BFLF2 or Orf27, respectively. Their recruitment of additional proteins leads to the assembly of a multicomponent NEC, coordinately regulating viral nucleocytoplasmic capsid egress. Here, the functionality of VZV, HCMV, MCMV and EBV core NECs was investigated by coimmunoprecipitation and confocal imaging analyses. Furthermore, a recombinant MCMV, harboring a replacement of ORF M50 by UL50, was analyzed both in vitro and in vivo. In essence, core NEC interactions were strictly limited to autologous NEC pairs and only included one measurable nonautologous interaction between the homologs of HCMV and MCMV. A comparative analysis of MCMV-WT versus MCMV-UL50-infected murine fibroblasts revealed almost identical phenotypes on the levels of protein and genomic replication kinetics. In infected BALB/c mice, virus spread to lung and other organs was found comparable between these viruses, thus stating functional complementarity. In conclusion, our study underlines that herpesviral core NEC proteins are functionally conserved regarding complementarity of core NEC interactions, which were found either virus-specific or restricted within subfamilies.

scholarly journals Evaluation of Antiviral Activities of Curcumin Derivatives against HSV-1 in Vero Cell Line

2010 ◽  
Vol 5 (12) ◽  
pp. 1934578X1000501 ◽  
Author(s):  
Keivan Zandi ◽  
Elissa Ramedani ◽  
Khosro Mohammadi ◽  
Saeed Tajbakhsh ◽  
Iman Deilami ◽  
...  
Keyword(s):  
Cell Culture ◽  
Antiviral Activity ◽  
Vero Cell ◽  
Cell Line ◽  
Antiviral Agents ◽  
Antiviral Drug ◽  
In Vitro Study ◽  
Vero Cell Line ◽  
Hsv 1

Antiviral drug resistance is one of the most common problems in medicine, and, therefore, finding new antiviral agents, especially from natural resources, seems to be necessary. This study was designed to assay the antiviral activity of curcumin and its new derivatives like gallium-curcumin and Cu-curcumin on replication of HSV-1 in cell culture. The research was performed as an in vitro study in which the antiviral activity of different concentrations of three substances including curcumin, Gallium-curcumin and Cu-curcumin were tested on HSV-1. The cytotoxicity of the tested compounds was also evaluated on the Vero cell line. The CC50 values for curcumin, gallium-curcumin and Cu-curcumin were 484.2 μg/mL, 255.8 μg/mL and 326.6 μg/mL, respectively, and the respective IC50 values 33.0 μg/mL, 13.9 μg/mL and 23.1 μg/mL. The calculated SI values were 14.6, 18.4 and 14.1, respectively. The results showed that curcumin and its new derivatives have remarkable antiviral effects on HSV-1 in cell culture.

scholarly journals Adenosine Analog NITD008 Is a Potent Inhibitor of Zika Virus

2016 ◽  
Vol 3 (4) ◽  
Author(s):  
Yong-Qiang Deng ◽  
Na-Na Zhang ◽  
Chun-Feng Li ◽  
Min Tian ◽  
Jia-Nan Hao ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Zika Virus ◽  
Potent Inhibitor ◽  
Antiviral Drug ◽  
Clinical Manifestations ◽  
Drug Screen ◽  
Adenosine Analog

Abstract The ongoing Zika virus (ZIKV) outbreaks have raised global concerns due to its unexpected clinical manifestations. Antiviral development is of high priority in response to the ZIKV emergency. In this study, we report that an adenosine analog NITD008 has potent in vitro and in vivo antiviral activity against ZIKV. The compound can effectively inhibit the historical and contemporary ZIKV strains in cultures as well as significantly reduce viremia and prevent mortality in A129 mice. Our results have demonstrated that NITD008 is potent inhibitor of ZIKV and can be used as reference inhibitor for future ZIKV antiviral drug screen and discovery.

scholarly journals Ribavirin shows antiviral activity against SARS-CoV-2 and downregulates the activity of TMPRSS2 and the expression of ACE2 in vitro

2021 ◽  
pp. 1-12 ◽  
Author(s):  
Mehmet Altay Unal ◽  
Ceylan Verda Bitirim ◽  
Gokce Yagmur Summak ◽  
Sidar Bereketoglu ◽  
Inci Cevher Zeytin ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Broad Spectrum ◽  
In Silico ◽  
Antiviral Drug ◽  
In Silico Analysis ◽  
Cell Types ◽  
Suppressive Effect ◽  
Inhibitory Effect ◽  
Molecular Techniques

Ribavirin is a guanosine analog with broad-spectrum antiviral activity against RNA viruses. Based on this, we aimed to show the anti-SARS-CoV-2 activity of this drug molecule via in vitro, in silico, and molecular techniques. Ribavirin showed antiviral activity in Vero E6 cells following SARS-CoV-2 infection, whereas the drug itself did not show any toxic effect over the concentration range tested. In silico analysis suggested that ribavirin has a broad-spectrum impact on SARS-CoV-2, acting at different viral proteins. According to the detailed molecular techniques, ribavirin was shown to decrease the expression of TMPRSS2 at both mRNA and protein levels 48 h after treatment. The suppressive effect of ribavirin in ACE2 protein expression was shown to be dependent on cell types. Finally, proteolytic activity assays showed that ribavirin also showed an inhibitory effect on the TMPRSS2 enzyme. Based on these results, we hypothesized that ribavirin may inhibit the expression of TMPRSS2 by modulating the formation of inhibitory G-quadruplex structures at the TMPRSS2 promoter. As a conclusion, ribavirin is a potential antiviral drug for the treatment against SARS-CoV-2, and it interferes with the effects of TMPRSS2 and ACE2 expression.

scholarly journals Anti-viral activity of enisamium iodide against viruses of influenza and ARVI’s on different cell lines

2020 ◽  
Vol 92 (11) ◽  
pp. 45-50
Author(s):  
V. V. Zarubaev ◽  
A. V. Slita ◽  
E. O. Sinegubova ◽  
A. A. Muryleva ◽  
I. N. Lavrentieva
Keyword(s):  
Antiviral Activity ◽  
Cell Lines ◽  
Antiviral Drug ◽  
Respiratory Viruses ◽  
Influenza Viruses ◽  
Parainfluenza Virus ◽  
Yield Reduction ◽  
In Vitro Experiments ◽  
Human Parainfluenza Virus

Influenza and ARVI represent the most numerous and dangerous group of causative agents of respiratory infections human. Aim. Characterization of the antiviral properties of enisamium iodide against human respiratory viruses in in vitro experiments. Materials and methods. In the course of experiments, the cytotoxic properties of enisamium iodide were studied against the cell lines Vero, MA-104, A549, L-41 and HEp-2. The antiviral activity of enisamium iodide was studied using virus yield reduction assay against influenza viruses, parainfluenza virus, respiratory syncytial virus, Coxsackie B3 and Coxsackie B4 viruses, as well as adenoviruses types 5 and 6. Results. The most sensitive to the action of enisamium iodide was the human parainfluenza virus, whose activity decreased by 2.3 orders of magnitude under the action of the drug in A549 cells. Of the cell cultures used, enisamium iodide exhibited the maximum antiviral effect in human lung carcinoma cells A549, where, in its presence, the level of reproduction of adenoviruses of types 5 and 6, Coxsackie viruses B3 and B4, and human parainfluenza virus decreased by an order of magnitude or more. The antiviral activity of enisamium iodide was least manifested in Vero cells. Conclusion. According to the results of in vitro experiments, enisamium iodide can be considered as an antiviral drug with a wide spectrum of activity against human respiratory viruses.

An expedited approach towards the rationale design of non-covalent SARS-CoV-2 main protease inhibitors with in vitro antiviral activity

2020 ◽  
Author(s):  
Naoya Kitamura ◽  
Michael Dominic Sacco ◽  
Chunlong Ma ◽  
Yanmei Hu ◽  
Julia Alma Townsend ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Binding Site ◽  
Antiviral Drug ◽  
Binding Pocket ◽  
Native Mass Spectrometry ◽  
Calpain Inhibitor ◽  
Site Analysis ◽  
Main Protease ◽  
Covalent Inhibitors

AbstractThe main protease (Mpro) of SARS-CoV-2 is a validated antiviral drug target. Several Mpro inhibitors have been reported with potent enzymatic inhibition and cellular antiviral activity, including GC376, boceprevir, calpain inhibitors II and XII, each containing a reactive warhead that covalently modifies the catalytic Cys145. In this study, we report an expedited drug discovery approach by coupling structure-based design and Ugi four-component (Ugi-4CR) reaction methodology to the design of non-covalent Mpro inhibitors. The most potent compound 23R had cellular antiviral activity similar to covalent inhibitors such as GC376. Our designs were guided by overlaying the structure of SARS-CoV Mpro + ML188 (R), a non-covalent inhibitor derived from Ug-4CR, with the X-ray crystal structures of SARS-CoV-2 Mpro + calpain inhibitor XII/GC376/UAWJ247. Binding site analysis suggests a strategy of extending the P2 and P3 substitutions in ML188 (R) to achieve optimal shape complementary with SARS-CoV-2 Mpro. Lead optimization led to the discovery of 23R, which inhibits SARS-CoV-2 Mpro and SARS-CoV-2 viral replication with an IC50 of 0.31 μM and EC50 of 1.27 μM, respectively. The binding and specificity of 23R to SARS-CoV-2 Mpro were confirmed in a thermal shift assay and native mass spectrometry assay. The co-crystal structure of SARS-CoV-2 Mpro with 23R revealed the P2 biphenyl fits snuggly into the S2 pocket and the benzyl group in the α-methylbenzyl faces towards the core of the enzyme, occupying a previously unexplored binding site located in between the S2 and S4 pockets. Overall, this study revealed the most potent non-covalent SARS-CoV-2 Mpro inhibitors reported to date and a novel binding pocket that can be explored for Mpro inhibitor design.

scholarly journals In Vitro Antiviral Activity of Heterophyllaea pustulata Extracts

2012 ◽  
Vol 7 (8) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Brenda S. Konigheim ◽  
Mauricio Beranek ◽  
Laura R. Comini ◽  
Javier J. Aguilar ◽  
Juliana Marioni ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Antiviral Drug ◽  
Neutral Red ◽  
Type I ◽  
Saint Louis ◽  
Aerial Parts ◽  
Uptake Assay ◽  
Simplex Virus ◽  
Hsv 1

The antiviral activity was tested of different polarity extracts, with differing chemical composition, obtained from aerial parts of Heterophyllaea pustulata Hook f. (Rubiaceae) against Herpes Simplex Virus Type I (HSV-1) and Saint Louis Encephalitis Virus (SLEV). The Vero cell line was employed as a host cell for the antiviral assessment of benzene (Ben), ethyl acetate (EtOAc) and ethanol (EtOH) extracts by means of the Neutral Red uptake assay and plaque reduction test. None of the extracts showed antiviral activity against SLEV. Only the extracts (Ben and EtOAc) with a high content of anthraquinones (AQs) inhibited HSV-1 replication, exhibiting Selectivity Index (SI) values of 2.7 and 2.4, respectively. Therefore, these extracts could be good candidates as natural sources for antiviral drug development against HSV-1.

scholarly journals The Cytomegalovirus Protein Kinase pUL97: Host Interactions, Regulatory Mechanisms and Antiviral Drug Targeting

2020 ◽  
Vol 8 (4) ◽  
pp. 515 ◽  
Author(s):  
Mirjam Steingruber ◽  
Manfred Marschall
Keyword(s):  
Protein Kinase ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Antiviral Treatment ◽  
Antiviral Drug ◽  
Host Interaction ◽  
Nuclear Egress ◽  
Viral Regulatory Proteins

Human cytomegalovirus (HCMV) expresses a variety of viral regulatory proteins that undergo close interaction with host factors including viral-cellular multiprotein complexes. The HCMV protein kinase pUL97 represents a viral cyclin-dependent kinase ortholog (vCDK) that determines the efficiency of HCMV replication via phosphorylation of viral and cellular substrates. A hierarchy of functional importance of individual pUL97-mediated phosphorylation events has been discussed; however, the most pronounced pUL97-dependent phenotype could be assigned to viral nuclear egress, as illustrated by deletion of the UL97 gene or pharmacological pUL97 inhibition. Despite earlier data pointing to a cyclin-independent functionality, experimental evidence increasingly emphasized the role of pUL97-cyclin complexes. Consequently, the knowledge about pUL97 involvement in host interaction, viral nuclear egress and additional replicative steps led to the postulation of pUL97 as an antiviral target. Indeed, validation experiments in vitro and in vivo confirmed the sustainability of this approach. Consequently, current investigations of pUL97 in antiviral treatment go beyond the known pUL97-mediated ganciclovir prodrug activation and henceforward include pUL97-specific kinase inhibitors. Among a number of interesting small molecules analyzed in experimental and preclinical stages, maribavir is presently investigated in clinical studies and, in the near future, might represent a first kinase inhibitor applied in the field of antiviral therapy.

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