Influenza virus surveillance to identify new mutations in the NS1 protein affecting innate immune responses and, as a consequence, the pathogenicity of the circulating viruses is highly relevant.
As a consequence, influenzaNS1 gene knockout virus delNS1 (an influenza A virus lacking the NS1 open reading frame) fails to replicate in normal cells but produces infectious particles in PKR-deficient cells.
This phenomenon occurs with multiple strains of IAV, is dependent on influenzaNS1 protein, and can be modulated by SUMOylation of an intrinsically disordered region (IDR) of NS1 expressed by the 1918 pandemic IAV strain.
NS1 mutations D189N and V194I impaired the ability of the NS1 protein to inhibit general gene expression, and recombinant viruses harboring these mutations were attenuated in a mouse model of influenza infection.
Our studies revealed an extensive diversity of influenza virus-specific CD4 T cells that includes T cells for each viral protein and for the unexpected immunogenicity of the NS1 protein.
Large-scale sequence analyses of influenza viruses revealed that nonstructural 1 (NS1) proteins from avian influenza viruses have a conserved C-terminal ESEV amino acid motif, while NS1 proteins from typical human influenza viruses have a C-terminal RSKV motif.
Lactobacillus casei carrying the NS1 protein could be developed into a universal oral influenza vaccine since the NS1 is highly conserved among influenza viruses.
We designed six primers targeting the matrix genes of influenza H1 and H3 and the NS1 gene of influenza B and developed a M-LAMP assay using a commercially available Master Mix and a real time fluorometer (Genie II, Optigene, UK) that displays real time amplification, time to positivity and amplicon annealing temperature (Tm).
In sum, our study uncovers the molecular basis of a major nuclear function of influenzaNS1 protein that causes potent blockage of host gene expression and contributes to inhibition of host immunity.
We propose that NS1 protein of both H5N1 and H11N1 subtypes of influenza viruses are capable of influencing host immune responses and possess necessary functionality to support apoptosis in host cells.
The fact that influenza A and influenza B virus NS1 proteins bind to NS1-I suggests that this cellular protein plays a role in the influenza virus life cycle.
Live attenuated influenza vaccine viral vector induces functional cytotoxic T-cell immune response against foreign CD8+ T-cell epitopes inserted into NA and NS1 genes using the 2A self-cleavage site.
Nonstructural protein 1 (NS1) proteins from avian influenza viruses like the 1918 pandemic NS1 are capable of inhibiting the key signaling integrator c-Abl (Abl1), resulting in massive cytopathic cell alterations.
The NS1 proteins of most avian influenza viruses bear the C-terminal ligand sequence Glu-Ser-Glu-Val (ESEV) for PDZ domains present in multiple host proteins, whereas no such motif is found in the NS1 homologues of seasonal human virus strains.