scholarly journals Ribonuclease fromBacillusActs as an Antiviral Agent against Negative- and Positive-Sense Single Stranded Human Respiratory RNA Viruses

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Raihan Shah Mahmud ◽  
Christin Müller ◽  
Yulia Romanova ◽  
Ahmed Mostafa ◽  
Vera Ulyanova ◽  
...  

Bacillus pumilusribonuclease (binase) was shown to be a promising antiviral agent in animal models and cell cultures. However, the mode of its antiviral action remains unknown. To assess the binase effect on intracellular viral RNA we have selected single stranded negative- and positive-sense RNA viruses, influenza virus, and rhinovirus, respectively, which annually cause respiratory illnesses and are characterized by high contagious nature, mutation rate, and antigen variability. We have shown that binase exerts an antiviral effect on both viruses at the same concentration, which does not alter the spectrum of A549 cellular proteins and expression of housekeeping genes. The titers of influenza A (H1N1pdm) virus and human rhinovirus serotype 1A were reduced by 40% and 65%, respectively. A preincubation of influenza virus with binase before infection significantly reduced viral titer after single-cycle replication of the virus. Using influenza A virus mini genome system we showed that binase reduced GFP reporter signaling indicating a binase action on the expression of viral mRNA. Binase reduced the level of H1N1pdm viral NP mRNA accumulation in A549 cells by 20%. Since the viral mRNA is a possible target for binase this agent could be potentially applied in the antiviral therapy against both negative- and positive-sense RNA viruses.

1999 ◽  
Vol 27 (01) ◽  
pp. 53-62 ◽  
Author(s):  
Makiko Kobayashi ◽  
Stephen M. Davis ◽  
Tokuichiro Utsunomiya ◽  
Richard B. Pollard ◽  
Fujio Suzuki

Gingyo-san is a crude drug containing extracts from 7 medicinal plants and fermented soybeans in a specific ratio. It has been used clinically in China as a therapeutic agent for the common cold. In the present study, we examined the antiviral effect of this agent on influenza virus infection in mice. Gingyo-san and its components were administered orally to mice 1 day before, then 1 and 4, days after the inhalation of a mouse-adopted strain of influenza A2(H2N2) virus. After infection with a 10 LD50of the virus, 100% of mice treated with 10 mg/kg of the agent survived as compared with a 0% survival of control mice treated with saline. Also, the mean survival days were ncreased and consolidation scores were decreased in treated mice as compared with those of control mice. Two components contained in the agent, extracts from Glycyrrhizae radix and Arctii fructus, expressed antiviral activities in mice infected with influenza virus. However, in vitro growth of influenza virus in MDCK cells or viability of the virus was not affected by these extracts or Gingyo-san. From these results Gingyo-san was shown to be an antiviral agent in mice infected with a lethal amount of a mouse-adopted strain of influenza A2virus.


2012 ◽  
Vol 56 (12) ◽  
pp. 6328-6333 ◽  
Author(s):  
Donald F. Smee ◽  
Mark von Itzstein ◽  
Beenu Bhatt ◽  
E. Bart Tarbet

ABSTRACTCompounds lacking oral activity may be delivered intranasally to treat influenza virus infections in mice. However, intranasal treatments greatly enhance the virulence of such virus infections. This can be partially compensated for by giving reduced virus challenge doses. These can be 100- to 1,000-fold lower than infections without such treatment and still cause equivalent mortality. We found that intranasal liquid treatments facilitate virus production (probably through enhanced virus spread) and that lung pneumonia was delayed by only 2 days relative to a 1,000-fold higher virus challenge dose not accompanied by intranasal treatments. In one study, zanamivir was 90 to 100% effective at 10 mg/kg/day by oral, intraperitoneal, and intramuscular routes against influenza A/California/04/2009 (H1N1) virus in mice. However, the same compound administered intranasally at 20 mg/kg/day for 5 days gave no protection from death although the time to death was significantly delayed. A related compound, Neu5Ac2en (N-acetyl-2,3-dehydro-2-deoxyneuraminic acid), was ineffective at 100 mg/kg/day. Intranasal zanamivir and Neu5Ac2en were 70 to 100% protective against influenza A/NWS/33 (H1N1) virus infections at 0.1 to 10 and 30 to 100 mg/kg/day, respectively. Somewhat more difficult to treat was A/Victoria/3/75 virus that required 10 mg/kg/day of zanamivir to achieve full protection. These results illustrate that treatment of influenza virus infections by the intranasal route requires consideration of both virus challenge dose and virus strain in order to avoid compromising the effectiveness of a potentially useful antiviral agent. In addition, the intranasal treatments were shown to facilitate virus replication and promote lung pathology.


2020 ◽  
Author(s):  
Shaohua Wang ◽  
Na Li ◽  
Shugang Jin ◽  
Ruihua Zhang ◽  
Tong Xu

Abstract Background: H9N2 influenza virus, a subtype of influenza A virus, can spread across different species and induce the respiratory infectious disease in humans, leading to a severe public health risk and a huge economic loss to poultry production. Increasing studies have shown that polymerase acidic (PA) subunit of RNA polymerase in ribonucleoproteins complex of H9N2 involves in crossing the host species barriers, the replication and airborne transmission of H9N2.Methods: Here, to further investigate the role of PA subunit during the infection of H9N2 influenza virus, we employed mass spectrometry (MS) to search the potential binding proteins of PA subunit of H9N2. Our MS results showed that programmed cell death protein 7 (PDCD7) is a binding target of PA subunit. Co-immunoprecipitation and pull-down assays further confirmed the interaction between PDCD7 and PA subunit. Overexpression of PA subunit in A549 lung cells greatly increased the levels of PDCD7 in the nuclear and induced cell death assayed by MTT assay.Results: Flow cytometry analysis and Western blot results showed that PA subunit overexpression significantly increased the expression of pro-apoptotic protein, bax and caspase 3, and induced cell apoptosis. However, knockout of PDCD7 effectively attenuated the effects of PA overexpression in cell apoptosis.Conclusions: In conclusion, the PA subunit of H9N2 bind with PDCD7 and regulated cell apoptosis, which provide new insights in the role of PA subunit during H9N2 influenza virus infection.


2015 ◽  
Vol 89 (15) ◽  
pp. 8011-8025 ◽  
Author(s):  
Cindy Chiang ◽  
Vladimir Beljanski ◽  
Kevin Yin ◽  
David Olagnier ◽  
Fethia Ben Yebdri ◽  
...  

ABSTRACTThe cytosolic RIG-I (retinoic acid-inducible gene I) receptor plays a pivotal role in the initiation of the immune response against RNA virus infection by recognizing short 5′-triphosphate (5′ppp)-containing viral RNA and activating the host antiviral innate response. In the present study, we generated novel 5′ppp RIG-I agonists of varieous lengths, structures, and sequences and evaluated the generation of the antiviral and inflammatory responses in human epithelial A549 cells, human innate immune primary cells, and murine models of influenza and chikungunya viral pathogenesis. A 99-nucleotide, uridine-rich hairpin 5′pppRNA termed M8 stimulated an extensive and robust interferon response compared to other modified 5′pppRNA structures, RIG-I aptamers, or poly(I·C). Interestingly, manipulation of the primary RNA sequence alone was sufficient to modulate antiviral activity and inflammatory response, in a manner dependent exclusively on RIG-I and independent of MDA5 and TLR3. Both prophylactic and therapeutic administration of M8 effectively inhibited influenza virus and dengue virus replicationin vitro. Furthermore, multiple strains of influenza virus that were resistant to oseltamivir, an FDA-approved therapeutic treatment for influenza, were highly sensitive to inhibition by M8. Finally, prophylactic M8 treatmentin vivoprolonged survival and reduced lung viral titers of mice challenged with influenza virus, as well as reducing chikungunya virus-associated foot swelling and viral load. Altogether, these results demonstrate that 5′pppRNA can be rationally designed to achieve a maximal RIG-I-mediated protective antiviral response against human-pathogenic RNA viruses.IMPORTANCEThe development of novel therapeutics to treat human-pathogenic RNA viral infections is an important goal to reduce spread of infection and to improve human health and safety. This study investigated the design of an RNA agonist with enhanced antiviral and inflammatory properties against influenza, dengue, and chikungunya viruses. A novel, sequence-dependent, uridine-rich RIG-I agonist generated a protective antiviral responsein vitroandin vivoand was effective at concentrations 100-fold lower than prototype sequences or other RNA agonists, highlighting the robust activity and potential clinical use of the 5′pppRNA against RNA virus infection. Altogether, the results identify a novel, sequence-specific RIG-I agonist as an attractive therapeutic candidate for the treatment of a broad range of RNA viruses, a pressing issue in which a need for new and more effective options persists.


2016 ◽  
Vol 90 (9) ◽  
pp. 4369-4382 ◽  
Author(s):  
Baoming Liu ◽  
Nan L. Li ◽  
Yang Shen ◽  
Xiaoyong Bao ◽  
Thomas Fabrizio ◽  
...  

ABSTRACTAccumulating data suggest that tripartite-motif-containing (TRIM) proteins participate in host responses to viral infections, either by acting as direct antiviral restriction factors or through regulating innate immune signaling of the host. Of >70 TRIMs, TRIM56 is a restriction factor of several positive-strand RNA viruses, including three members of the familyFlaviviridae(yellow fever virus, dengue virus, and bovine viral diarrhea virus) and a human coronavirus (OC43), and this ability invariably depends upon the E3 ligase activity of TRIM56. However, the impact of TRIM56 on negative-strand RNA viruses remains unclear. Here, we show that TRIM56 puts a check on replication of influenza A and B viruses in cell culture but does not inhibit Sendai virus or human metapneumovirus, two paramyxoviruses. Interestingly, the anti-influenza virus activity was independent of the E3 ligase activity, B-box, or coiled-coil domain. Rather, deletion of a 63-residue-long C-terminal-tail portion of TRIM56 abrogated the antiviral function. Moreover, expression of this short C-terminal segment curtailed the replication of influenza viruses as effectively as that of full-length TRIM56. Mechanistically, TRIM56 was found to specifically impede intracellular influenza virus RNA synthesis. Together, these data reveal a novel antiviral activity of TRIM56 against influenza A and B viruses and provide insights into the mechanism by which TRIM56 restricts these medically important orthomyxoviruses.IMPORTANCEOptions to treat influenza are limited, and drug-resistant influenza virus strains can emerge through minor genetic changes. Understanding novel virus-host interactions that alter influenza virus fitness may reveal new targets/approaches for therapeutic interventions. We show here that TRIM56, a tripartite-motif protein, is an intrinsic host restriction factor of influenza A and B viruses. Unlike its antiviral actions against positive-strand RNA viruses, the anti-influenza virus activity of TRIM56 was independent of the E3 ligase activity. Rather, expression of a short segment within the very C-terminal tail of TRIM56 inhibited the replication of influenza viruses as effectively as that of full-length TRIM56 by specifically targeting viral RNA synthesis. These data reveal the remarkable multifaceted activity of TRIM56, which has developed multiple domains to inhibit multiple viral families. They also raise the possibility of developing a broad-spectrum, TRIM56-based antiviral approach for addition to influenza prophylaxis and/or control strategies.


Biomedicines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1721
Author(s):  
Marta De Angelis ◽  
David Della-Morte ◽  
Gabriele Buttinelli ◽  
Angela Di Martino ◽  
Francesca Pacifici ◽  
...  

Polyphenols have been widely studied for their antiviral effect against respiratory virus infections. Among these, resveratrol (RV) has been demonstrated to inhibit influenza virus replication and more recently, it has been tested together with pterostilbene against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In the present work, we evaluated the antiviral activity of polydatin, an RV precursor, and a mixture of polyphenols and other micronutrients, named A5+, against influenza virus and SARS-CoV-2 infections. To this end, we infected Vero E6 cells and analyzed the replication of both respiratory viruses in terms of viral proteins synthesis and viral titration. We demonstrated that A5+ showed a higher efficacy in inhibiting both influenza virus and SARS-CoV-2 infections compared to polydatin treatment alone. Indeed, post infection treatment significantly decreased viral proteins expression and viral release, probably by interfering with any step of virus replicative cycle. Intriguingly, A5+ treatment strongly reduced IL-6 cytokine production in influenza virus-infected cells, suggesting its potential anti-inflammatory properties during the infection. Overall, these results demonstrate the synergic and innovative antiviral efficacy of A5+ mixture, although further studies are needed to clarify the mechanisms underlying its inhibitory effect.


Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1590
Author(s):  
Johanna Berg ◽  
Zia Weber ◽  
Mona Fechler-Bitteti ◽  
Andreas C. Hocke ◽  
Stefan Hippenstiel ◽  
...  

Influenza A virus (IAV) continuously causes epidemics and claims numerous lives every year. The available treatment options are insufficient and the limited pertinence of animal models for human IAV infections is hampering the development of new therapeutics. Bioprinted tissue models support studying pathogenic mechanisms and pathogen-host interactions in a human micro tissue environment. Here, we describe a human lung model, which consisted of a bioprinted base of primary human lung fibroblasts together with monocytic THP-1 cells, on top of which alveolar epithelial A549 cells were printed. Cells were embedded in a hydrogel consisting of alginate, gelatin and collagen. These constructs were kept in long-term culture for 35 days and their viability, expression of specific cell markers and general rheological parameters were analyzed. When the models were challenged with a combination of the bacterial toxins LPS and ATP, a release of the proinflammatory cytokines IL-1β and IL-8 was observed, confirming that the model can generate an immune response. In virus inhibition assays with the bioprinted lung model, the replication of a seasonal IAV strain was restricted by treatment with an antiviral agent in a dose-dependent manner. The printed lung construct provides an alveolar model to investigate pulmonary pathogenic biology and to support development of new therapeutics not only for IAV, but also for other viruses.


Author(s):  
А.Г. Емельянова ◽  
М.В. Никифорова ◽  
Е.С. Дон ◽  
Н.Р. Махмудова ◽  
И.Н. Фалынскова ◽  
...  

Цель исследования - изучение возможного прямого влияния препарата «Анаферон детский» на жизненный цикл вируса гриппа А в процессе развития инфекции, а также дозозависимости противовирусного эффекта in vitro . Методика. Исследование противовирусной активности препарата «Анаферон детский» in vitro было проведено с использованием культуры клеток MDCK (Madin Darby canine kidney) и эталонных штаммов вируса гриппа A (H1N1) pdm09: A/California/07/09 и А/California/04/09, полученных от ВОЗ. Использовались методы оценки подавления Анафероном детским вирусной репликации (по результатам иммуноферментного анализа по определению экспрессии внутренних белков NP и M1 вируса гриппа А) и его влияние на ультраструктурные особенности морфогенеза вируса гриппа методом электронной микроскопии. В качестве положительного контроля был использован Озельтамивир карбоксилат в концентрации 10 мкМ. Для мониторинга валидности экспериментальной модели в работе использовали клетки, зараженные вирусом без добавления экспериментальных образцов (контроль вируса), а также интактные клетки (клеточный контроль). Результаты. В ходе исследования показан дозозависимый противовирусный эффект препарата «Анаферон детский» для 3 тестируемых разведений - 1/8, 1/12, 1/16. Методом электронной микроскопии показано, что применение препарата «Анаферон детский» при сравнении с контрольным образцом влияло на процесс почкования вирионов. Заключение. Впервые показана дозозависимость противовирусного действия препарата «Анаферон детский», а также подтверждена его эффективность в отношении двух штаммов вируса пандемического гриппа А/H1N1. Документировано, что применение препарата «Анаферон детский» нарушает жизненный цикл вируса гриппа А. Механизмы развития такого эффекта требуют дополнительного изучения, однако можно предположить их связь с ИФН-индуцирующими свойствами препарата «Анаферон детский», так как было показано, что в начале лечения вирусной инфекции препарат вызывает индукцию синтеза белков системы интерферонов. The aim of this study was to evaluate a possible direct effect of Anaferon for Children on the life cycle of influenza A virus during infection development and a dose response of the antiviral effect in vitro. Methods. The in vitro antiviral activity of Anaferon for Children was studied on cultured MDCK cells and reference strains of influenza virus A (H1N1) pdm09: A/California/07/09 and A/California/04/09, both from the WHO. Inhibition of viral replication by Anaferon for Children and its effect on ultrastructural features of the influenza morphogenesis were evaluated using electron microscopy. Results. The study demonstrated a dose dependence of Anaferon for Children antiviral activity for three dilutions - 1/8, 1/12, and 1/16. Anaferon for Children affected the process of virion budding as compared to placebo. Conclusion. The study showed that the anti-influenza action of Anaferon for Children was dose-dependent and confirmed that this drug was effective against two strains of pandemic A/H1N1 influenza. Furthermore, Anaferon for children disrupted one or several stages of the virus life cycle.


mSphere ◽  
2017 ◽  
Vol 2 (4) ◽  
Author(s):  
Susan Schuster ◽  
Lotte E. Tholen ◽  
Gijs J. Overheul ◽  
Frank J. M. van Kuppeveld ◽  
Ronald P. van Rij

ABSTRACT The contribution of the RNA interference (RNAi) pathway in antiviral immunity in vertebrates has been widely debated. It has been proposed that RNAi possesses antiviral activity in mammalian systems but that its antiviral effect is masked by the potent antiviral interferon response in differentiated mammalian cells. In this study, we show that inactivation of the interferon response is not sufficient to uncover antiviral activity of RNAi in human epithelial cells infected with three wild-type positive-sense RNA viruses. Antiviral immunity in insects and plants is mediated by the RNA interference (RNAi) pathway in which viral long double-stranded RNA (dsRNA) is processed into small interfering RNAs (siRNAs) by Dicer enzymes. Although this pathway is evolutionarily conserved, its involvement in antiviral defense in mammals is the subject of debate. In vertebrates, recognition of viral RNA induces a sophisticated type I interferon (IFN)-based immune response, and it has been proposed that this response masks or inhibits antiviral RNAi. To test this hypothesis, we analyzed viral small RNA production in differentiated cells deficient in the cytoplasmic RNA sensors RIG-I and MDA5. We did not detect 22-nucleotide (nt) viral siRNAs upon infection with three different positive-sense RNA viruses. Our data suggest that the depletion of cytoplasmic RIG-I-like sensors is not sufficient to uncover viral siRNAs in differentiated cells. IMPORTANCE The contribution of the RNA interference (RNAi) pathway in antiviral immunity in vertebrates has been widely debated. It has been proposed that RNAi possesses antiviral activity in mammalian systems but that its antiviral effect is masked by the potent antiviral interferon response in differentiated mammalian cells. In this study, we show that inactivation of the interferon response is not sufficient to uncover antiviral activity of RNAi in human epithelial cells infected with three wild-type positive-sense RNA viruses.


Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1007 ◽  
Author(s):  
Xiaodong Tian ◽  
Kun Zhang ◽  
Jie Min ◽  
Can Chen ◽  
Ying Cao ◽  
...  

Influenza A virus (IAV) has developed strategies to utilize host metabolites which, after identification and isolation, can be used to discover the value of immunometabolism. During this study, to mimic the metabolic processes of influenza virus infection in human cells, we infect A549 cells with H1N1 (WSN) influenza virus and explore the metabolites with altered levels during the first cycle of influenza virus infection using ultra-high-pressure liquid chromatography–quadrupole time-of-flight mass spectrometer (UHPLC–Q-TOF MS) technology. We annotate the metabolites using MetaboAnalyst and the Kyoto Encyclopedia of Genes and Genomes pathway analyses, which reveal that IAV regulates the abundance of the metabolic products of host cells during early infection to provide the energy and metabolites required to efficiently complete its own life cycle. These metabolites are correlated with the tricarboxylic acid (TCA) cycle and mainly are involved in purine, lipid, and glutathione metabolisms. Concurrently, the metabolites interact with signal receptors in A549 cells to participate in cellular energy metabolism signaling pathways. Metabonomic analyses have revealed that, in the first cycle, the virus not only hijacks cell metabolism for its own replication, but also affects innate immunity, indicating a need for further study of the complex relationship between IAV and host cells.


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