scholarly journals Antiviral activity of novel oseltamivir derivatives against some influenza virus strains.

2014 ◽  
Vol 61 (3) ◽  
Author(s):  
Janusz Kocik ◽  
Marcin Kołodziej ◽  
Justyna Joniec ◽  
Magdalena Kwiatek ◽  
Michał Bartoszcze

The aim of this study was to investigate the in vitro cytotoxicity of oseltamivir derivatives and determine their activity against A/H1N1/PR/8/34 and A/H3N2/HongKong/8/68 - strains of influenza virus. Antiviral activity of these compounds was determined by using two methods. MTT staining was used to assess the viability of MDCK cells infected with influenza viruses and treated with various concentrations of drugs. In parallel, the effect of drugs on viral replication was assessed using the hemagglutination test. The most toxic compounds were: OS-64, OS-35, OS-29, OS-27 and OS-25, whereas OS-11, OS-20 and OS-23 were the least toxic ones. Statistically significant antiviral effect at a higher virus dose was shown by compounds: OS-11, OS-20, OS-27, OS-35, and OS-64. H3N2 virus was sensitive to 10-times lower concentrations of OS-11 and OS-35 than H1N1. At a lower infection dose, the antiviral activity was observed for OS-11, OS 27, OS-35 and OS-20. OS-64 turned out to be effective only at a high concentration. OS-23 showed no antiviral effect.

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.


2010 ◽  
Vol 54 (6) ◽  
pp. 2517-2524 ◽  
Author(s):  
Katrina Sleeman ◽  
Vasiliy P. Mishin ◽  
Varough M. Deyde ◽  
Yousuke Furuta ◽  
Alexander I. Klimov ◽  
...  

ABSTRACT Favipiravir (T-705) has previously been shown to have a potent antiviral effect against influenza virus and some other RNA viruses in both cell culture and in animal models. Currently, favipiravir is undergoing clinical evaluation for the treatment of influenza A and B virus infections. In this study, favipiravir was evaluated in vitro for its ability to inhibit the replication of a representative panel of seasonal influenza viruses, the 2009 A(H1N1) strains, and animal viruses with pandemic (pdm) potential (swine triple reassortants, H2N2, H4N2, avian H7N2, and avian H5N1), including viruses which are resistant to the currently licensed anti-influenza drugs. All viruses were tested in a plaque reduction assay with MDCK cells, and a subset was also tested in both yield reduction and focus inhibition (FI) assays. For the majority of viruses tested, favipiravir significantly inhibited plaque formation at 3.2 μM (0.5 μg/ml) (50% effective concentrations [EC50s] of 0.19 to 22.48 μM and 0.03 to 3.53 μg/ml), and for all viruses, with the exception of a single dually resistant 2009 A(H1N1) virus, complete inhibition of plaque formation was seen at 3.2 μM (0.5 μg/ml). Due to the 2009 pandemic and increased drug resistance in circulating seasonal influenza viruses, there is an urgent need for new drugs which target influenza. This study demonstrates that favipiravir inhibits in vitro replication of a wide range of influenza viruses, including those resistant to currently available drugs.


2009 ◽  
Vol 6 (4) ◽  
pp. 517-522 ◽  
Author(s):  
M. Rajbhandari ◽  
R. Mentel ◽  
P. K. Jha ◽  
R. P. Chaudhary ◽  
S. Bhattarai ◽  
...  

Methanolic extracts of 41 plant species belonging to 27 families used in the traditional medicine in Nepal have been investigated forin vitroantiviral activity against Herpes simplex virus type 1 (HSV-1) and influenza virus A by dye uptake assay in the systems HSV-1/Vero cells and influenza virus A/MDCK cells. The extracts ofAstilbe rivularis, Bergenia ciliata, Cassiope fastigiataandThymus linearisshowed potent anti-herpes viral activity. The extracts ofAllium oreoprasum, Androsace strigilosa, Asparagus filicinus, Astilbe rivularis, Bergenia ciliataandVerbascum thapsusexhibited strong anti-influenza viral activity. Only the extracts ofA. rivularisandB. ciliatademonstrated remarkable activity against both viruses.


2017 ◽  
Vol 91 (16) ◽  
Author(s):  
Mélia Magnen ◽  
Fabien Gueugnon ◽  
Antoine Guillon ◽  
Thomas Baranek ◽  
Virginie C. Thibault ◽  
...  

ABSTRACT Hemagglutinin (HA) of influenza virus must be activated by proteolysis before the virus can become infectious. Previous studies indicated that HA cleavage is driven by membrane-bound or extracellular serine proteases in the respiratory tract. However, there is still uncertainty as to which proteases are critical for activating HAs of seasonal influenza A viruses (IAVs) in humans. This study focuses on human KLK1 and KLK5, 2 of the 15 serine proteases known as the kallikrein-related peptidases (KLKs). We find that their mRNA expression in primary human bronchial cells is stimulated by IAV infection. Both enzymes cleaved recombinant HA from several strains of the H1 and/or H3 virus subtype in vitro, but only KLK5 promoted the infectivity of A/Puerto Rico/8/34 (H1N1) and A/Scotland/20/74 (H3N2) virions in MDCK cells. We assessed the ability of treated viruses to initiate influenza in mice. The nasal instillation of only the KLK5-treated virus resulted in weight loss and lethal outcomes. The secretion of this protease in the human lower respiratory tract is enhanced during influenza. Moreover, we show that pretreatment of airway secretions with a KLK5-selective inhibitor significantly reduced the activation of influenza A/Scotland/20/74 virions, providing further evidence of its importance. Differently, increased KLK1 secretion appeared to be associated with the recruitment of inflammatory cells in human airways regardless of the origin of inflammation. Thus, our findings point to the involvement of KLK5 in the proteolytic activation and spread of seasonal influenza viruses in humans. IMPORTANCE Influenza A viruses (IAVs) cause acute infection of the respiratory tract that affects millions of people during seasonal outbreaks every year. Cleavage of the hemagglutinin precursor by host proteases is a critical step in the life cycle of these viruses. Consequently, host proteases that activate HA can be considered promising targets for the development of new antivirals. However, the specific proteases that activate seasonal influenza viruses, especially H3N2 viruses, in the human respiratory tract have remain undefined despite many years of work. Here we demonstrate that the secreted, extracellular protease KLK5 (kallikrein-related peptidase 5) is efficient in promoting the infectivity of H3N2 IAV in vitro and in vivo. Furthermore, we found that its secretion was selectively enhanced in the human lower respiratory tract during a seasonal outbreak dominated by an H3N2 virus. Collectively, our data support the clinical relevance of this protease in human influenza pathogenesis.


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.


2008 ◽  
Vol 52 (11) ◽  
pp. 3889-3897 ◽  
Author(s):  
Natalia A. Ilyushina ◽  
Alan Hay ◽  
Neziha Yilmaz ◽  
Adrianus C. M. Boon ◽  
Robert G. Webster ◽  
...  

ABSTRACT We studied the effects of a neuraminidase inhibitor (oseltamivir) and an inhibitor of influenza virus polymerases (ribavirin) against two highly pathogenic H5N1 influenza viruses. In vitro, A/Vietnam/1203/04 virus (clade 1) was highly susceptible to oseltamivir carboxylate (50% inhibitory concentration [IC50] = 0.3 nM), whereas A/Turkey/15/06 virus (clade 2.2) had reduced susceptibility (IC50 = 5.5 nM). In vivo, BALB/c mice were treated with oseltamivir (1, 10, 50, or 100 mg/kg of body weight/day), ribavirin (37.5, 55, or 75 mg/kg/day), or the combination of both drugs for 8 days, starting 4 h before virus inoculation. Monotherapy produced a dose-dependent antiviral effect against the two H5N1 viruses in vivo. Three-dimensional analysis of the drug-drug interactions revealed that oseltamivir and ribavirin interacted principally in an additive manner, with several exceptions of marginal synergy or marginal antagonism at some concentrations. The combination of ribavirin at 37.5 mg/kg/day and oseltamivir at 1 mg/kg/day and the combination of ribavirin at 37.5 mg/kg/day and oseltamivir at 10 mg/kg/day were synergistic against A/Vietnam/1203/04 and A/Turkey/15/06 viruses, respectively. These optimal oseltamivir-ribavirin combinations significantly inhibited virus replication in mouse organs, prevented the spread of H5N1 viruses beyond the respiratory tract, and abrogated the cytokine response (P < 0.01). Importantly, we observed clear differences between the efficacies of the drug combinations against two H5N1 viruses: higher doses were required for the protection of mice against A/Turkey/15/06 virus than for the protection of mice against A/Vietnam/1203/04 virus. Our preliminary results suggest that oseltamivir-ribavirin combinations can have a greater or lesser antiviral effect than monotherapy, depending on the H5N1 virus and the concentrations used.


2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S294-S295
Author(s):  
Andrew Smith ◽  
Laura Rodriguez-Garcia ◽  
Maya El Ghouayel ◽  
Luis Martinez-Sobrido ◽  
Stephen Dewhurst

Abstract Background The Live Attenuated Influenza Virus (LAIV) used in the United States is based on the cold-passaged A/AnnArbor/6/60 strain (AA). An alternative LAIV (Len), developed from the cold-passaged A/Leningrad/134/17/57 strain, has also been used in some countries outside the United States. Recent concerns with the efficacy and safety of the current US LAIV warrant the development of an improved LAIV. Methods We used in vitro minireplicon and multicycle viral growth assays to analyze the combined effects of polymerase mutations from LAIV (AA) and LAIV (Len) on the phenotype of PR8. Mini-replicon assays were performed in HEK-293T cells with firefly luciferase under the control of the influenza virus NP promoter; we controlled for cell density with a constitutively active Renilla luciferase. Multicycle growth curve experiments were performed at 33°C, 37°C, and 39°C in MDCK cells with an m.o.i. of 0.001. Mean values for triplicate infections at 12, 24, 48, and 72 hours were plotted as TCID50/mL. Results Control experiments showed replication of PR8 (AA) and PR8 (Len) in MDCK cells was significantly decreased as compared with WT PR8 at 37°C and 39°C at 24–48 hour time points, but not at 33C (the temperature of nasal passages). We found that polymerase activity was up to 3 logs more temperature-sensitive (ts) at 37°C and 39°C with the combined Len and AA mutations using the mini-replicon assay. In the growth curve experiments, the combined Len and AA mutations conferred up to a 4-log decrease in replication levels at 37°C as compared with PR8 (Len) and an even greater decrease compared with PR8 (AA). Conclusion Our findings suggest combining the AA and Len LAIV polymerase mutations decreases LAIV replication at body temperature (37°C), as compared with either LAIV alone. This could be useful in developing an improved LAIV that is safer in vulnerable hosts (e.g., children under the age of 2 who may be vulnerable to wheezing), while also permitting dose escalation that might result in greater efficacy. Minireplicon assay. Polymerase activity of combination mutants. Multicycle replication kinetics of combination mutants (red) against PR8 Len (black) at 33C (solid), 37C (dashed) and 39C (dotted). Disclosures All authors: No reported disclosures.


2019 ◽  
Vol 93 (18) ◽  
Author(s):  
Felix Broecker ◽  
Allen Zheng ◽  
Nungruthai Suntronwong ◽  
Weina Sun ◽  
Mark J. Bailey ◽  
...  

ABSTRACT Influenza viruses express two surface glycoproteins, the hemagglutinin (HA) and the neuraminidase (NA). Anti-NA antibodies protect from lethal influenza virus challenge in the mouse model and correlate inversely with virus shedding and symptoms in humans. Consequently, the NA is a promising target for influenza virus vaccine design. Current seasonal vaccines, however, poorly induce anti-NA antibodies, partly because of the immunodominance of the HA over the NA when the two glycoproteins are closely associated. To address this issue, here we investigated whether extending the stalk domain of the NA could render it more immunogenic on virus particles. Two recombinant influenza viruses based on the H1N1 strain A/Puerto Rico/8/1934 (PR8) were rescued with NA stalk domains extended by 15 or 30 amino acids. Formalin-inactivated viruses expressing wild-type NA or the stalk-extended NA variants were used to vaccinate mice. The virus with the 30-amino-acid stalk extension induced significantly higher anti-NA IgG responses (characterized by increased in vitro antibody-dependent cellular cytotoxicity [ADCC] activity) than the wild-type PR8 virus, while anti-HA IgG levels were unaffected. Similarly, extending the stalk domain of the NA of a recent H3N2 virus enhanced the induction of anti-NA IgGs in mice. On the basis of these results, we hypothesize that the subdominance of the NA can be modulated if the protein is modified such that its height surpasses that of the HA on the viral membrane. Extending the stalk domain of NA may help to enhance its immunogenicity in influenza virus vaccines without compromising antibody responses to HA. IMPORTANCE The efficacy of influenza virus vaccines could be improved by enhancing the immunogenicity of the NA protein. One of the reasons for its poor immunogenicity is the immunodominance of the HA over the NA in many seasonal influenza virus vaccines. Here we demonstrate that, in the mouse model, extending the stalk domain of the NA protein can enhance its immunogenicity on virus particles and overcome the immunodominance of the HA without affecting antibody responses to the HA. The antibody repertoire is broadened by the extended NA and includes additional ADCC-active antibodies. Our findings may assist in the efforts toward more effective influenza virus vaccines.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mariana Baz ◽  
Zeineb M’hamdi ◽  
Julie Carbonneau ◽  
Sophie Lavigne ◽  
Christian Couture ◽  
...  

Abstract The mouse is the most widely used animal model for influenza virus research. However, the susceptibility of mice to seasonal influenza virus depends on the strain of mouse and on the strain of the influenza virus. Seasonal A/H3N2 influenza viruses do not replicate well in mice and therefore they need to be adapted to this animal model. In this study, we generated a mouse-adapted A/H3N2 virus (A/Switzerland/9715293/2013 [MA-H3N2]) by serial passaging in mouse lungs that exhibited greater virulence compared to the wild-type virus (P0-H3N2). Seven mutations were found in the genome of MA-H3N2: PA(K615E), NP(G384R), NA(G320E) and HA(N122D, N144E, N246K, and A304T). Using reverse genetics, two synergistically acting genes were found as determinants of the pathogenicity in mice. First, the HA substitutions were shown to enhanced viral replication in vitro and, second, the PA-K615E substitution increased polymerase activity, although did not alter virus replication in vitro or in mice. Notably, single mutations had only limited effects on virulence in vitro. In conclusion, a co-contribution of HA and PA mutations resulted in a lethal mouse model of seasonal A/H3N2 virus. Such adapted virus is an excellent tool for evaluation of novel drugs or vaccines and for study of influenza pathogenesis.


2014 ◽  
Vol 9 (1) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Lubomira Nikolaeva-Glomb ◽  
Luchia Mukova ◽  
Nadya Nikolova ◽  
Ilian Badjakov ◽  
Ivayla Dincheva ◽  
...  

Wild berry species are known to exhibit a wide range of pharmacological activities. They have long been traditionally applied for their antiseptic, antimicrobial, cardioprotective and antioxidant properties. The aim of the present study is to reveal the potential for selective antiviral activity of total methanol extracts, as well as that of the anthocyanins and the non-anthocyanins from the following wild berries picked in Bulgaria: strawberry ( Fragaria vesca L.) and raspberry ( Rubus idaeus L.) of the Rosaceae plant family, and bilberry ( Vaccinium myrtillis L.) and lingonberry ( Vaccinium vitis-idaea L) of the Ericaceae. The antiviral effect has been tested against viruses that are important human pathogens and for which chemotherapy and/or chemoprophylaxis is indicated, namely poliovirus type 1 (PV-1) and coxsackievirus B1 (CV-B1) from the Picornaviridae virus family, human respiratory syncytial virus A2 (HRSV-A2) from the Paramyxoviridae and influenza virus A/H3N2 of Orthomyxoviridae. Wild berry fruits are freeze-dried and ground, then total methanol extracts are prepared. Further the extracts are fractioned by solid phase extraction and the non-anthocyanin and anthocyanin fractions are eluted. The in vitro antiviral effect is examined by the virus cytopathic effect (CPE) inhibition test. The results reveal that the total extracts of all tested berry fruits inhibit the replication of CV-B1 and influenza A virus. CV-B1 is inhibited to the highest degree by both bilberry and strawberry, as well as by lingonberry total extracts, and influenza A by bilberry and strawberry extracts. Anthocyanin fractions of all wild berries strongly inhibit the replication of influenza virus A/H3N2. Given the obtained results it is concluded that wild berry species are a valuable resource of antiviral substances and the present study should serve as a basis for further detailed research on the matter.


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