Nanobodies mapped to cross-reactive and divergent epitopes on A(H7N9) influenza hemagglutinin using yeast display

AbstractInfluenza H7N9 virus continues to cause infections in humans and represents a significant pandemic risk. During the most recent 5th epidemic wave in 2016/17 two distinct lineages with increased human infections and wider geographical spread emerged. In preparation for any future adaptations, broadly reactive antibodies against H7N9 are required for surveillance, therapy and prophylaxis. In this study we have isolated a panel of nanobodies (Nbs) with broad reactivity across H7 influenza strains, including H7N9 strains between 2013 and 2017. We also describe Nbs capable of distinguishing between the most recent high and low pathogenicity Yangtze River Delta lineage H7N9 strains. Nanobodies were classified into 5 distinct groups based on their epitope footprint determined using yeast display and mutational scanning. The epitope footprint of Nbs capable of distinguishing high pathogenic (HP) A/Guangdong/17SF003/2016 from low pathogenic (LP) A/Hong Kong/125/2017 (H7N9) were correlated to natural sequence divergence in the head domain at lysine 164. Several Nbs binding to the head domain were capable of viral neutralisation. The potency of one nanobody NB7-14 could be increased over 1000-fold to 113 pM by linking two Nbs together. Nbs specific for distinct epitopes on H7N9 may be useful for surveillance or therapy in human or veterinary settings.

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Risk Assessment of Fifth-Wave H7N9 Influenza A Viruses in Mammalian Models

Journal of Virology ◽

10.1128/jvi.01740-18 ◽

2018 ◽

Vol 93 (1) ◽

Cited By ~ 10

Author(s):

Xiangjie Sun ◽

Jessica A. Belser ◽

Claudia Pappas ◽

Joanna A. Pulit-Penaloza ◽

Nicole Brock ◽

...

Keyword(s):

Risk Assessment ◽

Animal Models ◽

Avian Influenza ◽

Sudden Increase ◽

Sequencing Analysis ◽

Pathogenic Avian Influenza ◽

H7n9 Influenza ◽

Human Infections ◽

Epidemic Wave ◽

Brain Tissues

ABSTRACT The fifth wave of the H7N9 influenza epidemic in China was distinguished by a sudden increase in human infections, an extended geographic distribution, and the emergence of highly pathogenic avian influenza (HPAI) viruses. Genetically, some H7N9 viruses from the fifth wave have acquired novel amino acid changes at positions involved in mammalian adaptation, antigenicity, and hemagglutinin cleavability. Here, several human low-pathogenic avian influenza (LPAI) and HPAI H7N9 virus isolates from the fifth epidemic wave were assessed for their pathogenicity and transmissibility in mammalian models, as well as their ability to replicate in human airway epithelial cells. We found that an LPAI virus exhibited a similar capacity to replicate and cause disease in two animal species as viruses from previous waves. In contrast, HPAI H7N9 viruses possessed enhanced virulence, causing greater lethargy and mortality, with an extended tropism for brain tissues in both ferret and mouse models. These HPAI viruses also showed signs of adaptation to mammalian hosts by acquiring the ability to fuse at a lower pH threshold than other H7N9 viruses. All of the fifth-wave H7N9 viruses were able to transmit among cohoused ferrets but exhibited a limited capacity to transmit by respiratory droplets, and deep sequencing analysis revealed that the H7N9 viruses sampled after transmission showed a reduced amount of minor variants. Taken together, we conclude that the fifth-wave HPAI H7N9 viruses have gained the ability to cause enhanced disease in mammalian models and with further adaptation may acquire the ability to cause an H7N9 pandemic. IMPORTANCE The potential pandemic risk posed by avian influenza H7N9 viruses was heightened during the fifth epidemic wave in China due to the sudden increase in the number of human infections and the emergence of antigenically distinct LPAI and HPAI H7N9 viruses. In this study, a group of fifth-wave HPAI and LPAI viruses was evaluated for its ability to infect, cause disease, and transmit in small-animal models. The ability of HPAI H7N9 viruses to cause more severe disease and to replicate in brain tissues in animal models as well as their ability to fuse at a lower pH threshold than LPAI H7N9 viruses suggests that the fifth-wave H7N9 viruses have evolved to acquire novel traits with the potential to pose a higher risk to humans. Although the fifth-wave H7N9 viruses have not yet gained the ability to transmit efficiently by air, continuous surveillance and risk assessment remain essential parts of our pandemic preparedness efforts.

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Adjuvanted recombinant hemagglutinin H7 vaccine to highly pathogenic influenza A(H7N9) elicits high and sustained antibody responses in healthy adults

npj Vaccines ◽

10.1038/s41541-021-00287-7 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Christine M. Oshansky ◽

◽

James King ◽

Di Lu ◽

James Zhou ◽

...

Keyword(s):

Influenza A ◽

Study Groups ◽

Cross Reactivity ◽

Healthy Adults ◽

Response Strategy ◽

Seroprotection Rate ◽

Highly Pathogenic ◽

Homologous Virus ◽

Human Infections ◽

Epidemic Wave

AbstractAn unprecedented number of human infections with avian influenza A(H7N9) in the fifth epidemic wave during the winter of 2016–2017 in China and their antigenic divergence from the viruses that emerged in 2013 prompted development of updated vaccines for pandemic preparedness. We report on the findings of a clinical study in healthy adults designed to evaluate the safety and immunogenicity of three dose levels of recombinant influenza vaccine derived from highly pathogenic A/Guangdong/17SF003/2016 (H7N9) virus adjuvanted with AS03 or MF59 oil-in water emulsions. Most of the six study groups meet the FDA CBER-specified vaccine licensure criterion of 70% seroprotection rate (SPR) for hemagglutination inhibition antibodies to the homologous virus. A substantial proportion of subjects show high cross-reactivity to antigenically distinct heterologous A(H7N9) viruses from the first epidemic wave of 2013. These results provide critical information to develop a pandemic response strategy and support regulatory requirements for vaccination under Emergency Use Authorization.

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Structural and Molecular Characterization of the Hemagglutinin from the Fifth-Epidemic-Wave A(H7N9) Influenza Viruses

Journal of Virology ◽

10.1128/jvi.00375-18 ◽

2018 ◽

Vol 92 (16) ◽

Cited By ~ 14

Author(s):

Hua Yang ◽

Paul J. Carney ◽

Jessie C. Chang ◽

Zhu Guo ◽

James Stevens

Keyword(s):

Public Health ◽

Avian Influenza ◽

Influenza A ◽

Human Infection ◽

Influenza Viruses ◽

Surface Proteins ◽

Health Concern ◽

Public Health Concern ◽

H7n9 Influenza ◽

Epidemic Wave

ABSTRACTThe avian influenza A(H7N9) virus continues to cause human infections in China and is a major ongoing public health concern. Five epidemic waves of A(H7N9) infection have occurred since 2013, and the recent fifth epidemic wave saw the emergence of two distinct lineages with elevated numbers of human infection cases and broader geographic distribution of viral diseases compared to the first four epidemic waves. Moreover, highly pathogenic avian influenza (HPAI) A(H7N9) viruses were also isolated during the fifth epidemic wave. Here, we present a detailed structural and biochemical analysis of the surface hemagglutinin (HA) antigen from viruses isolated during this recent epidemic wave. Results highlight that, compared to the 2013 virus HAs, the fifth-wave virus HAs remained a weak binder to human glycan receptor analogs. We also studied three mutations, V177K-K184T-G219S, that were recently reported to switch a 2013 A(H7N9) HA to human-type receptor specificity. Our results indicate that these mutations could also switch the H7 HA receptor preference to a predominantly human binding specificity for both fifth-wave H7 HAs analyzed in this study.IMPORTANCEThe A(H7N9) viruses circulating in China are of great public health concern. Here, we report a molecular and structural study of the major surface proteins from several recent A(H7N9) influenza viruses. Our results improve the understanding of these evolving viruses and provide important information on their receptor preference that is central to ongoing pandemic risk assessment.

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Immune-engineered H7N9 influenza hemagglutinin improves protection against viral influenza virus challenge

Human Vaccines & Immunotherapeutics ◽

10.1080/21645515.2020.1793711 ◽

2020 ◽

Vol 16 (9) ◽

pp. 2042-2050

Author(s):

Hyesun Jang ◽

Lauren M. Meyers ◽

Christine Boyle ◽

Anne S. De Groot ◽

Lenny Moise ◽

...

Keyword(s):

Influenza Virus ◽

Virus Challenge ◽

Influenza Hemagglutinin ◽

Viral Influenza ◽

H7n9 Influenza

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A Potent Germline-Like Human Monoclonal Antibody Targeting a Novel pH-Sensitive Epitope on H7N9 Influenza Hemagglutinin

SSRN Electronic Journal ◽

10.2139/ssrn.3155911 ◽

2018 ◽

Author(s):

Fei Yu ◽

He Song ◽

Yanling Wu ◽

So Young Chang ◽

Lili Wang ◽

...

Keyword(s):

Monoclonal Antibody ◽

Human Monoclonal Antibody ◽

Ph Sensitive ◽

Influenza Hemagglutinin ◽

H7n9 Influenza ◽

Antibody Targeting

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Treatment of Highly Pathogenic H7N9 Virus-Infected Mice with Baloxavir Marboxil

Viruses ◽

10.3390/v11111066 ◽

2019 ◽

Vol 11 (11) ◽

pp. 1066 ◽

Cited By ~ 1

Author(s):

Maki Kiso ◽

Seiya Yamayoshi ◽

Yuri Furusawa ◽

Masaki Imai ◽

Yoshihiro Kawaoka

Keyword(s):

Virus Infection ◽

Influenza A ◽

H7n9 Virus ◽

Neuraminidase Inhibitors ◽

Influenza A Viruses ◽

Lethal Challenge ◽

Highly Pathogenic ◽

Limited Efficacy ◽

H7n9 Influenza ◽

Influenza H7n9 Virus

Viral neuraminidase inhibitors show limited efficacy in mice infected with H7N9 influenza A viruses isolated from humans. Although baloxavir marboxil protected mice from lethal challenge infection with a low pathogenic avian influenza H7N9 virus isolated from a human, its efficacy in mice infected with a recent highly pathogenic version of H7N9 human isolates is unknown. Here, we examined the efficacy of baloxavir marboxil in mice infected with a highly pathogenic human H7N9 virus, A/Guangdong/17SF003/2016. Treatment of infected mice with a single 1.5 mg/kg dose of baloxavir marboxil protected mice from the highly pathogenic human H7N9 virus infection as effectively as oseltamivir treatment at 50 mg/kg twice a day for five days. Daily treatment for five days at 15 or 50 mg/kg of baloxavir marboxil showed superior therapeutic efficacy, largely preventing virus replication in respiratory organs. These results indicate that baloxavir marboxil is a valuable candidate treatment for human patients suffering from highly pathogenic H7N9 virus infection.

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New hemagglutinin dual-receptor-binding pattern of a human-infecting influenza A (H7N9) virus isolated after fifth epidemic wave

Virus Evolution ◽

10.1093/ve/veaa021 ◽

2020 ◽

Vol 6 (1) ◽

Author(s):

Lei Guo ◽

Nan Li ◽

Wenlong Li ◽

Jienan Zhou ◽

Ruotong Ning ◽

...

Keyword(s):

Receptor Binding ◽

Influenza A ◽

Human Infection ◽

Binding Property ◽

H7n9 Virus ◽

Receptor Binding Site ◽

Highly Pathogenic ◽

Influenza H7n9 Virus ◽

Epidemic Wave ◽

Human Receptor

Abstract Since 2013, influenza H7N9 virus has caused five epidemic waves of human infection. The virus evolved from low pathogenic to highly pathogenic in wave 5, 2017, while the prevalence of host receptor-binding tropism in human-infecting viruses maintained dual-receptor-binding property with preference for avian receptor. A human-infecting H7N9 virus was isolated after the fifth epidemic wave and possessed an avian and human dual-receptor specificity, with a moderately higher affinity for human receptor binding. A V186I (H3 numbering) substitution in the receptor-binding site of the hemagglutinin (HA) molecule is responsible for the alteration of the dual-receptor-binding tropism. Viral strains which contain I186 amino acid of avian- and human-infecting H7N9 viruses were all isolated during or after wave 5, and their HA genes clustered in a same phylogenetic clade together with 2018–9 H7N9 isolates, highlights a new evolutionary path for human adaption of natural H7N9 viruses.

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SUSCEPTIBILITY OF COMMERCIAL NEURAMINIDASE INHIBITORS AGAINST 2013 A/H7N9 INFLUENZA VIRUS: A DOCKING AND MOLECULAR DYNAMICS STUDY

Journal of Theoretical and Computational Chemistry ◽

10.1142/s0219633613500697 ◽

2013 ◽

Vol 12 (07) ◽

pp. 1350069 ◽

Cited By ~ 1

Author(s):

ZHIWEI YANG ◽

FEI WU ◽

JUNXING LIU ◽

SHUQIU WANG ◽

XIAOHUI YUAN

Keyword(s):

Molecular Dynamics ◽

Influenza A ◽

Continuous Monitoring ◽

Antiviral Drug ◽

Binding Affinities ◽

The Novel ◽

Novel Virus ◽

H7n9 Influenza ◽

Dynamics Simulations ◽

Human Infections

The latest influenza A ( H 7 N 9) virus attracted a worldwide attention due to the first report of human infections and the continuing reported cases in China. In this work, homology modeling, docking and molecular dynamics simulations were combined to study the interactions between neuraminidase ( N 9_2013, from novel A/ H 7 N 9 virus) and agents zanamivir, oseltamivir, peramivir. It was found that N 9_2013 protein is structurally close to the template (PDB code: 1F8B), especially the active site. The binding properties of N 9_2013 protein were nearly identical to those of template. As a result, the three available drugs should be still efficacious for the new emerging A ( H 7 N 9) virus. However, the stabilities of docked complexes and binding affinities (Eint) were slightly reduced, in contrast to the corresponding inhibitor-template complexes, with the values of -82.27 (-84.30), -78.84 (-80.28) and -77.52 (-81.94) kcal mol-1, respectively. Besides, R292K mutation might induce the resistance of the novel virus to the commercial inhibitors. Thus, it arouses the need for continuous monitoring of antiviral drug susceptibilities.

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An update on clinical trials of H7N9 influenza vaccines

Journal of Applied Virology ◽

10.21092/jav.v3i3.37 ◽

2014 ◽

Vol 3 (3) ◽

pp. 55 ◽

Cited By ~ 1

Author(s):

Jian Luo

Keyword(s):

Clinical Trials ◽

Human Population ◽

Influenza Vaccines ◽

Current Status ◽

H7n9 Virus ◽

Phase I Clinical Trials ◽

Mortality And Morbidity ◽

H7n9 Influenza ◽

Influenza H7n9 Virus ◽

Significant Mortality

In February 2013, a novel avian influenza H7N9 virus emerged in China, and has caused significant mortality and morbidity in humans. Since the human population is expected to have little or no pre-existing immunity against A/H7N9 virus, there is an urgent need to develop effective vaccines. The present review summarizes the preliminary immunogenicity data of H7N9 vaccines from recently completed phase I clinical trials. The current status of the various types of H7N9 vaccines that are in clinical evaluation and the information of clinical trial applications for H7N9 vaccine in China are also provided.

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