An M2-V27A channel blocker demonstrates potent in vitro and in vivo antiviral activities against amantadine-sensitive and -resistant influenza A viruses

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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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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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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Heterosubtypic Protection Conferred by the Human Monoclonal Antibody PN-SIA28 against Influenza A Virus Lethal Infections in Mice

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00118-15 ◽

2015 ◽

Vol 59 (5) ◽

pp. 2647-2653 ◽

Cited By ~ 1

Author(s):

Miguel Retamal ◽

Yacine Abed ◽

Chantal Rhéaume ◽

Francesca Cappelletti ◽

Nicola Clementi ◽

...

Keyword(s):

Monoclonal Antibody ◽

Body Weight ◽

Influenza Virus ◽

Influenza A ◽

Human Monoclonal Antibody ◽

Influenza A Viruses ◽

Virus Challenge ◽

Influenza A H1n1

ABSTRACTPN-SIA28 is a human monoclonal antibody (Hu-MAb) targeting highly conserved epitopes within the stem portion of the influenza virus hemagglutinin (HA) (N. Clementi, et al, PLoS One 6:e28001, 2011,http://dx.doi.org/10.1371/journal.pone.0028001). Previousin vitrostudies demonstrated PN-SIA28 neutralizing activities against phylogenetically divergent influenza A subtypes. In this study, the protective activity of PN-SIA28 was evaluated in mice inoculated with lethal influenza A/WSN/33 (H1N1), A/Quebec/144147/09 (H1N1)pdm09, and A/Victoria/3/75 (H3N2) viruses. At 24 h postinoculation (p.i.), animals received PN-SIA28 intraperitoneally (1 or 10 mg/kg of body weight) or 10 mg/kg of unrelated Hu-MAb (mock). Body weight loss and mortality rate (MR) were recorded for 14 days postinfection (p.i.). Lung viral titers (LVT) were determined at day 5 p.i. In A/WSN/33 (H1N1)-infected groups, all untreated and mock-receiving mice died, whereas MRs of 87.5% and 25% were observed in mice that received PN-SIA28 1 and 10 mg/kg, respectively. In influenza A(H1N1) pdm09-infected groups, an MR of 75% was recorded for untreated and mock-treated groups, whereas the PN-SIA28 1-mg/kg and 10-mg/kg groups had rates of 62.5% and 0%, respectively. In A/Victoria/3/75 (H3N2)-infected animals, untreated and mock-treated animals had MRs of 37.5% and 25%, respectively, and no mortalities were recorded after PN-SIA28 treatments. Accordingly, PN-SIA28 treatments significantly reduced weight losses and resulted in a ≥1-log reduction in LVT compared to the control in all infection groups. This study confirms that antibodies targeting highly conserved epitopes in the influenza HA stem region, like PN-SIA28, not only neutralize influenza A viruses of clinically relevant subtypesin vitrobut also, more importantly, protect from a lethal influenza virus challengein vivo.

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Monoclonal antibodies targeting the influenza virus N6 neuraminidase

10.1101/2021.02.15.431355 ◽

2021 ◽

Author(s):

Shirin Strohmeier ◽

Fatima Amanat ◽

Juan Manuel Carreño ◽

Florian Krammer

Keyword(s):

Monoclonal Antibodies ◽

Influenza A ◽

Neutralization Assay ◽

Escape Mutant ◽

Influenza A Viruses ◽

Highly Pathogenic ◽

Lateral Ridge

AbstractInfluenza A viruses are a diverse species that include 16 hemagglutinin (HA) subtypes and 9 neuraminidase (NA) subtypes. While the antigenicity of many HA subtypes is reasonably well studied, less is known about NA antigenicity, especially when it comes to non-human subtypes that only circulate in animal reservoirs. The N6 NA subtypes are mostly found in viruses infecting birds. However, they have also been identified in viruses that infect mammals, such as swine and seals. More recently, highly pathogenic H5N6 subtype viruses have caused rare infections and mortality in humans. Here, we generated murine mAbs to the N6 NA, characterized their breadth and antiviral properties in vitro and in vivo and mapped their epitopes by generating escape mutant viruses. We found that the antibodies had broad reactivity across the American and Eurasian N6 lineages, but relatively little binding and inhibition of the H5N6 NA. Several of the antibodies exhibited strong NA inhibition activity and some also showed activity in the antibody dependent cellular cytotoxicity reporter assay and neutralization assay. In addition, we generated escape mutant viruses for six monoclonal antibodies and found mutations on the lateral ridge of the NA. Lastly, we observed variable protection in H4N6 and H5N6 mouse challenge models when the antibodies were given prophylactically.ImportanceThe N6 NA has recently gained prominence due to the emergence of highly pathogenic H5N6 viruses. Currently, there is limited characterization of the antigenicity of avian N6 neuraminidase. Our data is an important first step towards a better understanding of the N6 NA antigenicity.

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Attenuation and immunogenicity in mice of temperature-sensitive influenza viruses expressing truncated NS1 proteins

Journal of General Virology ◽

10.1099/vir.0.80991-0 ◽

2005 ◽

Vol 86 (10) ◽

pp. 2817-2821 ◽

Cited By ~ 36

Author(s):

Ana M. Falcón ◽

Ana Fernandez-Sesma ◽

Yurie Nakaya ◽

Thomas M. Moran ◽

Juan Ortín ◽

...

Keyword(s):

Influenza A ◽

Influenza Viruses ◽

Wild Type Virus ◽

Temperature Sensitive ◽

Ns1 Protein ◽

Wild Type ◽

Influenza A Viruses ◽

Lethal Challenge

It was previously shown that two mutant influenza A viruses expressing C-terminally truncated forms of the NS1 protein (NS1-81 and NS1-110) were temperature sensitive in vitro. These viruses contain HA, NA and M genes derived from influenza A/WSN/33 H1N1 virus (mouse-adapted), and the remaining five genes from human influenza A/Victoria/3/75 virus. Mice intranasally infected with the NS1 mutant viruses showed undetectable levels of virus in lungs at day 3, whereas those infected with the NS1 wild-type control virus still had detectable levels of virus at this time. Nevertheless, the temperature-sensitive mutant viruses induced specific cellular and humoral immune responses similar to those induced by the wild-type virus. Mice immunized with the NS1 mutant viruses were protected against a lethal challenge with influenza A/WSN/33 virus. These results indicate that truncations in the NS1 protein resulting in temperature-sensitive phenotypes in vitro correlate with attenuation in vivo without compromising viral immunogenicity, an ideal characteristic for live attenuated viral vaccines.

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Targeting host calpain proteases decreases influenza A virus infection

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00314.2015 ◽

2016 ◽

Vol 310 (7) ◽

pp. L689-L699 ◽

Cited By ~ 10

Author(s):

Fany Blanc ◽

Laetitia Furio ◽

Dorothée Moisy ◽

Hui-Ling Yen ◽

Michel Chignard ◽

...

Keyword(s):

Influenza A ◽

Molecular Mechanisms ◽

Influenza A Viruses ◽

Host Immune Responses ◽

Proinflammatory Mediators ◽

Acute Respiratory Diseases ◽

Calpain Inhibition ◽

Interfering Rna

Influenza A viruses (IAV) trigger contagious acute respiratory diseases. A better understanding of the molecular mechanisms of IAV pathogenesis and host immune responses is required for the development of more efficient treatments of severe influenza. Calpains are intracellular proteases that participate in diverse cellular responses, including inflammation. Here, we used in vitro and in vivo approaches to investigate the role of calpain signaling in IAV pathogenesis. Calpain expression and activity were found altered in IAV-infected bronchial epithelial cells. With the use of small-interfering RNA (siRNA) gene silencing, specific synthetic inhibitors of calpains, and mice overexpressing calpastatin, we found that calpain inhibition dampens IAV replication and IAV-triggered secretion of proinflammatory mediators and leukocyte infiltration. Remarkably, calpain inhibition has a protective impact in IAV infection, since it significantly reduced mortality of mice challenged not only by seasonal H3N2- but also by hypervirulent H5N1 IAV strains. Hence, our study suggests that calpains are promising therapeutic targets for treating IAV acute pneumonia.

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3-Indoleacetonitrile Is Highly Effective in Treating Influenza A Virus Infection In Vitro and In Vivo

Viruses ◽

10.3390/v13081433 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1433

Author(s):

Xuejin Zhao ◽

Lianzhong Zhao ◽

Ya Zhao ◽

Kun Huang ◽

Wenxiao Gong ◽

...

Keyword(s):

Influenza A ◽

Mdck Cells ◽

A549 Cells ◽

H1n1 Influenza ◽

Indole Derivatives ◽

Influenza A Viruses ◽

Toxic Concentration ◽

Influenza Activity

Influenza A viruses are serious zoonotic pathogens that continuously cause pandemics in several animal hosts, including birds, pigs, and humans. Indole derivatives containing an indole core framework have been extensively studied and developed to prevent and/or treat viral infection. This study evaluated the anti-influenza activity of several indole derivatives, including 3-indoleacetonitrile, indole-3-carboxaldehyde, 3-carboxyindole, and gramine, in A549 and MDCK cells. Among these compounds, 3-indoleacetonitrile exerts profound antiviral activity against a broad spectrum of influenza A viruses, as tested in A549 cells. Importantly, in a mouse model, 3-indoleacetonitrile with a non-toxic concentration of 20 mg/kg effectively reduced the mortality and weight loss, diminished lung virus titers, and alleviated lung lesions of mice lethally challenged with A/duck/Hubei/WH18/2015 H5N6 and A/Puerto Rico/8/1934 H1N1 influenza A viruses. The antiviral properties enable the potential use of 3-indoleacetonitrile for the treatment of IAV infection.

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Influenza A viruses with different amino acid residues at PB2-627 display distinct replication properties in vitro and in vivo : Revealing the sequence plasticity of PB2-627 position

Virology ◽

10.1016/j.virol.2014.09.008 ◽

2014 ◽

Vol 468-470 ◽

pp. 545-555 ◽

Cited By ~ 12

Author(s):

Alex W.H. Chin ◽

Olive T.W. Li ◽

Chris K.P. Mok ◽

Miko K.W. Ng ◽

Malik Peiris ◽

...

Keyword(s):

Amino Acid ◽

Influenza A ◽

Amino Acid Residues ◽

Influenza A Viruses

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Brevilin A, a Sesquiterpene Lactone, Inhibits the Replication of Influenza A Virus In Vitro and In Vivo

Viruses ◽

10.3390/v11090835 ◽

2019 ◽

Vol 11 (9) ◽

pp. 835 ◽

Cited By ~ 4

Author(s):

Xiaoli Zhang ◽

Yiping Xia ◽

Li Yang ◽

Jun He ◽

Yaolan Li ◽

...

Keyword(s):

Sesquiterpene Lactone ◽

Post Infection ◽

Nuclear Export ◽

Influenza A ◽

Sesquiterpene Lactones ◽

Influenza A Viruses ◽

Suppression Effect ◽

Influenza A H1n1

With the emergence of drug-resistant strains of influenza A viruses (IAV), new antivirals are needed to supplement the existing counter measures against IAV infection. We have previously shown that brevilin A, a sesquiterpene lactone isolated from C. minima, suppresses the infection of influenza A/PR/8/34 (H1N1) in vitro. Here, we further investigate the antiviral activity and mode of action of brevilin A against different IAV subtypes. Brevilin A inhibited the replication of influenza A H1N1, H3N2, and H9N2 viruses in vitro. The suppression effect of brevilin A was observed as early as 4–8 hours post infection (hpi). Furthermore, we determined that brevilin A inhibited viral replication in three aspects, including viral RNA (vRNA) synthesis, expression of viral mRNA, and protein encoded from the M and NS segments, and nuclear export of viral ribonucleoproteins (vRNPs). The anti-IAV activity of brevilin A was further confirmed in mice. A delayed time-to-death with 50% surviving up to 14 days post infection was obtained with brevilin A (at a dose of 25 mg/kg) treated animals compared to the control cohorts. Together, these results are encouraging for the exploration of sesquiterpene lactones with similar structure to brevilin A as potential anti-influenza therapies.

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