influenza virus
Pathogenesis and ImmunityBroad Hemagglutinin-Specific Memory B Cell Expansion by Seasonal Influenza Virus Infection Reflects Early-Life Imprinting and Adaptation to the Infecting VirusRapid and vigorous virus-specific antibody responses to influenza virus infection and vaccination result from activation of preexisting virus-specific memory B cells (MBCs). Understanding the effects of different forms of influenza virus exposure on MBC populations is therefore an important guide to the development of effective immunization strategies. We demonstrate that exposure to the influenza hemagglutinin via natural infection...
Virus-Cell InteractionsCeramide Suppresses Influenza A Virus Replication In VitroUnderstanding the effect of sphingolipid metabolism on viral pathogenesis provide important insights into the development of therapeutic strategies against microbial infections. In this study, we demonstrate a critical role of ceramide during influenza A virus infection. We demonstrate that ceramide produced through de novo biosynthesis possess an antiviral role. These observations unlock new opportunities for the development...
Vaccines and Antiviral AgentsMutations in Influenza A Virus Neuraminidase and Hemagglutinin Confer Resistance against a Broadly Neutralizing Hemagglutinin Stem AntibodyInfluenza A virus is a public health threat for which currently available vaccines are not always effective. Broadly neutralizing antibodies that bind to the highly conserved stem region of the influenza virus hemagglutinin (HA) can neutralize many influenza virus strains. To understand how influenza virus can become resistant or escape such antibodies, we propagated influenza A virus in vitro with escalating concentrations of...
Virus-Cell Interactions | SpotlightInfluenza Virus NS1 Protein-RNA Interactome Reveals Intron TargetingA key virulence factor of influenza A virus is the NS1 protein, which inhibits various cellular processes to facilitate viral gene expression. The NS1 protein is localized in the nucleus and in the cytoplasm during infection. In the nucleus, NS1 has functions related to inhibition of gene expression that involve protein-protein and protein-RNA interactions. While several studies have elucidated the protein interactome of NS1, we still...
Vaccines and Antiviral AgentsSalinomycin Inhibits Influenza Virus Infection by Disrupting Endosomal Acidification and Viral Matrix Protein 2 FunctionInfluenza virus is a main cause of viral respiratory infection in humans as well as animals, occasionally with high mortality. Circulation of influenza viruses resistant to the matrix protein 2 (M2) inhibitor, amantadine, is highly prevalent. Moreover, the frequency of detection of viruses resistant to the neuraminidase inhibitors, including oseltamivir phosphate (OSV-P) or zanamivir, is also increasing. These issues highlight the need...
Vaccines and Antiviral AgentsComplement C3 Plays a Key Role in Inducing Humoral and Cellular Immune Responses to Influenza Virus Strain-Specific Hemagglutinin-Based or Cross-Protective M2 Extracellular Domain-Based VaccinationComplement is the well-known innate immune defense system involved in the opsonization and lysis of pathogens but is less studied in establishing adaptive immunity after vaccination. Influenza virus HA-based vaccination confers protection via strain-specific neutralizing antibodies, whereas M2e-based vaccination induces a broad spectrum of protection by immunity against the conserved M2e epitopes. This study revealed the critical roles...
Virus-Cell InteractionsFunctional Evolution of the 2009 Pandemic H1N1 Influenza Virus NS1 and PA in Humans- Pathogenesis and ImmunityA Dual Motif in the Hemagglutinin of H5N1 Goose/Guangdong-Like Highly Pathogenic Avian Influenza Virus Strains Is Conserved from Their Early Evolution and Increases both Membrane Fusion pH and Virulence
Zoonotic highly pathogenic avian influenza viruses (HPAIV) have raised serious public health concerns of a novel pandemic. Their prime virulence determinant is the polybasic hemagglutinin (HA) cleavage site. However, required coadaptations in the HA (and other genes) remained uncertain. Here, we identified the dual motif 123R/124I in the HA head that increases the activation pH of HA-mediated membrane fusion, essential for virus genome...
- Genetic Diversity and EvolutionThe Influenza B Virus Hemagglutinin Head Domain Is Less Tolerant to Transposon Mutagenesis than That of the Influenza A Virus
Influenza viruses cause seasonal epidemics and result in significant human morbidity and mortality. Influenza viruses persist in the human population through generating mutations in the hemagglutinin head domain that prevent antibody recognition. Despite the similar selective pressures on influenza A and B viruses, influenza A virus displays a higher rate and breadth of antigenic variability than influenza B virus. A transposon...
- Vaccines and Antiviral AgentsBroadly Reactive Human Monoclonal Antibodies Elicited following Pandemic H1N1 Influenza Virus Exposure Protect Mice against Highly Pathogenic H5N1 Challenge
The rise in zoonotic infections of humans by emerging influenza viruses is a worldwide public health concern. The majority of recent zoonotic human influenza cases were caused by H7N9 and H5Nx viruses and were associated with high morbidity and mortality. In addition, seasonal influenza viruses are estimated to cause up to 650,000 deaths annually worldwide. Currently available antiviral treatment options include only neuraminidase...