Hemagglutinin Specificity and Neuraminidase Coding Capacity of Neuraminidase-Deficient Influenza Viruses

Replication-Competent Neuraminidase-Negative Influenza H5N1 Viruses

Influenza viruses resistant to neuraminidase inhibitors.

Neuraminidase inhibitors (NAIs) are antiviral drugs for treatment and prophylaxis of influenza. By blocking the activity of the enzyme neuraminidase, NAIs prevent new viral particles from being released. The increasing use of NAIs brings into focus the risk of drug resistance arising to the class. There are three levels of antiviral resistance according to the way that resistance can be detecte...

Discordant antigenic drift of neuraminidase and hemagglutinin in H1N1 and H3N2 influenza viruses.

Seasonal epidemics caused by influenza virus are driven by antigenic changes (drift) in viral surface glycoproteins that allow evasion from preexisting humoral immunity. Antigenic drift is a feature of not only the hemagglutinin (HA), but also of neuraminidase (NA). We have evaluated the antigenic evolution of each protein in H1N1 and H3N2 viruses used in vaccine formulations during the last 15...

Tetherin Sensitivity of Influenza A Viruses Is Strain Specific: Role of Hemagglutinin and Neuraminidase.

UNLABELLED The expression of the antiviral host cell factor tetherin is induced by interferon and can inhibit the release of enveloped viruses from infected cells. The Vpu protein of HIV-1 antagonizes the antiviral activity of tetherin, and tetherin antagonists with Vpu-like activity have been identified in other viruses. In contrast, it is incompletely understood whether tetherin inhibits infl...

Influenza virus hemagglutinin and neuraminidase cytoplasmic tails control particle shape.

The cytoplasmic tails of the influenza virus glycoproteins hemagglutinin (HA) and neuraminidase (NA) are highly conserved in sequence for all virus subtypes and it is believed that assembly of this enveloped virus depends on interactions of these domains with cytoplasmic viral components. However, it is possible to rescue altered influenza viruses lacking either the HA or NA cytoplasmic tails. ...