In Vitro Efficacies of Oseltamivir Carboxylate and Zanamivir against Equine Influenza A Viruses

Equines are susceptible to respiratory viruses such as influenza and parainfluenza. Respiratory diseases have adversely impacted economies all over the world. This study was intended to determine the presence of influenza and parainfluenza viruses in unvaccinated horses from some regions of the state of São Paulo, Brazil. Blood serum collected from 72 equines of different towns in this state was tested by hemagglutination inhibition test to detect antibodies for both viruses using the corresponding antigens. About 98.6% (71) and 97.2% (70) of the equines responded with antibody protective titers (≥ 80 HIU/25µL) H7N7 and H3N8 subtypes of influenza A viruses, respectively. All horses (72) also responded with protective titers (≥ 80) HIU/25µL against the parainfluenza virus. The difference between mean antibody titers to H7N7 and H3N8 subtypes of influenza A viruses was not statistically significant (p > 0.05). The mean titers for influenza and parainfluenza viruses, on the other hand, showed a statistically significant difference (p < 0.001). These results indicate a better antibody response from equines to parainfluenza 3 virus than to the equine influenza viruses. No statistically significant differences in the responses against H7N7 and H3N8 subtypes of influenza A and parainfluenza 3 viruses were observed according to the gender (female, male) or the age (≤ 2 to 20 years-old) groups. This study provides evidence of the concomitant presence of two subtypes of the equine influenza A (H7N7 and H3N8) viruses and the parainfluenza 3 virus in equines in Brazil. Thus, it is advisable to vaccinate equines against these respiratory viruses.

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Viruses harness YxxØ motif to interact with host AP2M1 for replication: A vulnerable broad-spectrum antiviral target

Science Advances ◽

10.1126/sciadv.aba7910 ◽

2020 ◽

Vol 6 (35) ◽

pp. eaba7910

Author(s):

Shuofeng Yuan ◽

Hin Chu ◽

Jingjing Huang ◽

Xiaoyu Zhao ◽

Zi-Wei Ye ◽

...

Keyword(s):

Broad Spectrum ◽

Influenza A ◽

Host Protein ◽

Influenza A Viruses ◽

Protein Protein Interaction ◽

Enterovirus A71 ◽

Evolutionarily Conserved ◽

Immunodeficiency Virus

Targeting a universal host protein exploited by most viruses would be a game-changing strategy that offers broad-spectrum solution and rapid pandemic control including the current COVID-19. Here, we found a common YxxØ-motif of multiple viruses that exploits host AP2M1 for intracellular trafficking. A library chemical, N-(p-amylcinnamoyl)anthranilic acid (ACA), was identified to interrupt AP2M1-virus interaction and exhibit potent antiviral efficacy against a number of viruses in vitro and in vivo, including the influenza A viruses (IAVs), Zika virus (ZIKV), human immunodeficiency virus, and coronaviruses including MERS-CoV and SARS-CoV-2. YxxØ mutation, AP2M1 depletion, or disruption by ACA causes incorrect localization of viral proteins, which is exemplified by the failure of nuclear import of IAV nucleoprotein and diminished endoplasmic reticulum localization of ZIKV-NS3 and enterovirus-A71-2C proteins, thereby suppressing viral replication. Our study reveals an evolutionarily conserved mechanism of protein-protein interaction between host and virus that can serve as a broad-spectrum antiviral target.

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In vitro Anti-viral Activity of Psoraleae Semen Water Extract against Influenza A Viruses

Frontiers in Pharmacology ◽

10.3389/fphar.2016.00460 ◽

2016 ◽

Vol 7 ◽

Cited By ~ 13

Author(s):

Jang-gi Choi ◽

Young-Hee Jin ◽

Ji-Hye Kim ◽

Tae Woo Oh ◽

Nam-Hui Yim ◽

...

Keyword(s):

Influenza A ◽

Water Extract ◽

Influenza A Viruses ◽

Viral Activity

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Influenza A Virus Inhibits RSV Infection via a Two-Wave Expression of IFIT Proteins

Viruses ◽

10.3390/v12101171 ◽

2020 ◽

Vol 12 (10) ◽

pp. 1171

Author(s):

Yaron Drori ◽

Jasmine Jacob-Hirsch ◽

Rakefet Pando ◽

Aharona Glatman-Freedman ◽

Nehemya Friedman ◽

...

Keyword(s):

Influenza A Virus ◽

Influenza A ◽

Influenza Viruses ◽

Mass Spectrometry Analysis ◽

Influenza A Viruses ◽

Rsv Infection ◽

Syncytial Virus ◽

Mouse Lungs

Influenza viruses and respiratory syncytial virus (RSV) are respiratory viruses that primarily circulate worldwide during the autumn and winter seasons. Seasonal surveillance has shown that RSV infection generally precedes influenza. However, in the last four winter seasons (2016–2020) an overlap of the morbidity peaks of both viruses was observed in Israel, and was paralleled by significantly lower RSV infection rates. To investigate whether the influenza A virus inhibits RSV, human cervical carcinoma (HEp2) cells or mice were co-infected with influenza A and RSV. Influenza A inhibited RSV growth, both in vitro and in vivo. Mass spectrometry analysis of mouse lungs infected with influenza A identified a two-wave pattern of protein expression upregulation, which included members of the interferon-induced protein with the tetratricopeptide (IFITs) family. Interestingly, in the second wave, influenza A viruses were no longer detectable in mouse lungs. In addition, knockdown and overexpression of IFITs in HEp2 cells affected RSV multiplicity. In conclusion, influenza A infection inhibits RSV infectivity via upregulation of IFIT proteins in a two-wave modality. Understanding the immune system involvement in the interaction between influenza A and RSV viruses will contribute to the development of future treatment strategies against these viruses.

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In Vitro Combinations of Baloxavir Acid and Other Inhibitors against Seasonal Influenza A Viruses

Viruses ◽

10.3390/v12101139 ◽

2020 ◽

Vol 12 (10) ◽

pp. 1139

Author(s):

Liva Checkmahomed ◽

Blandine Padey ◽

Andrés Pizzorno ◽

Olivier Terrier ◽

Manuel Rosa-Calatrava ◽

...

Keyword(s):

Cell Viability ◽

Influenza A ◽

Ex Vivo ◽

Synergistic Effects ◽

Prolonged Treatment ◽

Influenza A Viruses ◽

Human Airway Epithelium ◽

Influenza A H1n1 ◽

Approved Drugs

Two antiviral classes, the neuraminidase inhibitors (NAIs) and polymerase inhibitors (baloxavir marboxil and favipiravir) can be used to prevent and treat influenza infections during seasonal epidemics and pandemics. However, prolonged treatment may lead to the emergence of drug resistance. Therapeutic combinations constitute an alternative to prevent resistance and reduce antiviral doses. Therefore, we evaluated in vitro combinations of baloxavir acid (BXA) and other approved drugs against influenza A(H1N1)pdm09 and A(H3N2) subtypes. The determination of an effective concentration inhibiting virus cytopathic effects by 50% (EC50) for each drug and combination indexes (CIs) were based on cell viability. CompuSyn software was used to determine synergism, additivity or antagonism between drugs. Combinations of BXA and NAIs or favipiravir had synergistic effects on cell viability against the two influenza A subtypes. Those effects were confirmed using a physiological and predictive ex vivo reconstructed human airway epithelium model. On the other hand, the combination of BXA and ribavirin showed mixed results. Overall, BXA stands as a good candidate for combination with several existing drugs, notably oseltamivir and favipiravir, to improve in vitro antiviral activity. These results should be considered for further animal and clinical evaluations.

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In VitroAssessment of the Immunological Significance of a Human Monoclonal Antibody Directed to the Influenza A Virus Nucleoprotein

Clinical and Vaccine Immunology ◽

10.1128/cvi.00339-13 ◽

2013 ◽

Vol 20 (8) ◽

pp. 1333-1337 ◽

Cited By ~ 24

Author(s):

Rogier Bodewes ◽

Martina M. Geelhoed-Mieras ◽

Jens Wrammert ◽

Rafi Ahmed ◽

Patrick C. Wilson ◽

...

Keyword(s):

Monoclonal Antibody ◽

Influenza A Virus ◽

Influenza A ◽

Viral Antigen ◽

Human Monoclonal Antibody ◽

Cell Cytotoxicity ◽

Influenza A Viruses ◽

Dependent Cell ◽

Infected Cells

ABSTRACTInfluenza A viruses cause annual epidemics and occasionally pandemics. Antibodies directed to the conserved viral nucleoprotein (NP) may play a role in immunity against various influenza A virus subtypes. Here, we assessed the immunological significance of a human monoclonal antibody directed to NPin vitro. This antibody bound to virus-infected cells but did not display virus-neutralizing activity, complement-dependent cell cytotoxicity, or opsonization of viral antigen for improved antigen presentation to CD8+T cells by dendritic cells.

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The influenza A virus nucleoprotein gene controls the induction of both subtype specific and cross-reactive cytotoxic T cells.

Journal of Experimental Medicine ◽

10.1084/jem.160.2.552 ◽

1984 ◽

Vol 160 (2) ◽

pp. 552-563 ◽

Cited By ~ 119

Author(s):

A R Townsend ◽

J J Skehel

Keyword(s):

T Cells ◽

Influenza A ◽

Cytotoxic T Cells ◽

Target Cells ◽

Spleen Cells ◽

Influenza A Viruses ◽

Group A ◽

Selection Of

Using genetically typed recombinant influenza A viruses that differ only in their genes for nucleoprotein, we have demonstrated that repeated stimulation in vitro of C57BL/6 spleen cells primed in vivo with E61-13-H17 (H3N2) virus results in the selection of a population of cytotoxic T lymphocytes (CTL) whose recognition of infected target cells maps to the gene for nucleoprotein of the 1968 virus. Influenza A viruses isolated between 1934 and 1979 fall into two groups defined by their ability to sensitize target cells for lysis by these CTL: 1934-1943 form one group (A/PR/8/34 related) and 1946-1979 form the second group (A/HK/8/68 related). These findings complement and extend our previous results with an isolated CTL clone with specificity for the 1934 nucleoprotein (27, 28). It is also shown that the same spleen cells derived from mice primed with E61-13-H17 virus in vivo, but maintained in identical conditions by stimulation with X31 virus (which differs from the former only in the origin of its gene for NP) in vitro, results in the selection of CTL that cross-react on target cells infected with A/PR/8/1934 (H1N1) or A/Aichi/1968 (H3N2). These results show that the influenza A virus gene for NP can play a role in selecting CTL with different specificities and implicate the NP molecule as a candidate for a target structure recognized by both subtype-directed and cross-reactive influenza A-specific cytotoxic T cells.

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Use of influenza A viruses expressing reporter genes to assess the frequency of double infections in vitro

Journal of General Virology ◽

10.1099/vir.0.042671-0 ◽

2012 ◽

Vol 93 (8) ◽

pp. 1645-1648 ◽

Cited By ~ 9

Author(s):

R. Bodewes ◽

N. J. Nieuwkoop ◽

R. J. Verburgh ◽

R. A. M. Fouchier ◽

A. D. M. E. Osterhaus ◽

...

Keyword(s):

Influenza A ◽

Single Cells ◽

Reporter Genes ◽

Influenza Viruses ◽

Influenza A Viruses ◽

Double Infection ◽

Madin Darby Canine Kidney ◽

Darby Canine Kidney ◽

Canine Kidney

Exchange of gene segments between mammalian and avian influenza A viruses may lead to the emergence of potential pandemic influenza viruses. Since co-infection of single cells with two viruses is a prerequisite for reassortment to take place, we assessed frequencies of double-infection in vitro using influenza A/H5N1 and A/H1N1 viruses expressing the reporter genes eGFP or mCherry. Double-infected A549 and Madin–Darby canine kidney cells were detected by confocal microscopy and flow cytometry.

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