A method of producing a virus like particle (VLP) in a plant is provided. The method comprises introducing a first nucleic acid and a second nucleic acid into the plant, or portion of the plant. The first nucleic acid comprises a first regulatory region active in the plant and operatively linked to a nucleotide sequence encoding a structural virus protein. The second nucleic acid comprises a second regulatory region active in the plant and operatively linked to a nucleotide sequence encoding a channel protein, for example but not limited to a proton channel protein. The plant or portion of the plant is incubated under conditions that permit the expression of the nucleic acids, thereby producing the VLP.

Provided herein are membrane enveloped virus-like particles (VLPs), and methods of use and synthesis thereof. In particular, yeast-cell-derived VLPs are provided that comprise surface-displayed glycoproteins and/or multiple virally-derived proteins.

The development of a computationally optimized influenza HA protein that elicits broadly reactive immune response to all H5N1 influenza virus isolates is described. The optimized HA protein was developed through a series of HA protein alignments, and subsequent generation of consensus sequences, for clade 2 H5N1 influenza virus isolates. The final consensus HA amino acid sequence was reverse translated and optimized for expression in mammalian cells. Influenza virus-like particles containing the optimized HA protein are an effective vaccine against H5N1 influenza virus infection in animals.

Compositions and methods to prepare influenza virus-like particles (VLPs) are provided.

A method of producing a virus like particle (VLP) in a plant comprising modified hemagglutinin is provided. The method comprises introducing a nucleic acid comprising a regulatory region active in the plant and operatively linked to a nucleotide sequence encoding a modified influenza hemagglutinin (HA) protein into the plant, or portion of the plant, the modified HA protein comprises a modified proteolytic loop. Followed by incubating the plant or portion of the plant under conditions that permit the expression of the nucleic acids, thereby producing the VLP. The modified proteolytic loop may comprise one or more protease cleavage sites exhibiting reduced or abolished cleavage by a protease. The nucleotide sequence encoding the HA may be selected from the group consisting of B HA, C, H1, H2, H3, H4, H5, H6, H7, H8, H9, H10, H11, H12, H13, H14, H15, and H16. Also described is a virus like particle (VLP) produced by the method, and plants expressing the VLP. The virus like particle (VLP) may comprise plant-specific N-glycans, or modified N-glycans.

Disclosed are universal influenza based on a truncated influenza hemagglutin (HA) protein lacking a head domain (hrHA). Also disclosed is a composition comprising a nanoparticle coated with a disclosed hrHA polypeptide. Also disclosed is a composition comprising a virus like particle (VLP) expressing on its surface a disclosed hrHA polypeptide.

The present invention provides, among other things, a novel and improved method for generating mosaic influenza antigenic polypeptides including hemagglutinin (HA) and neuraminidase (NA) polypeptides based on unique combination of epitope patterns that maximize exposure to epitopes present across multiple HA or NA sequences and therefore improved influenza strain coverage. In particular, the present invention provides engineered H1N1 influenza hemagglutinin (HA) polypeptides that are comprised of novel combinations of protective epitopes and antigenic regions from multiple H1N1 viral strains. Such engineered HA polypeptides have improved properties over HA polypeptides developed through conventional approaches that rely on consensus alignments of viral sequences.

The present invention provides a vaccine containing virus-like particles derived from virus particles having an envelope, in which a lipid-component content of the virus-like particles is reduced relative to a lipid-component content of the virus particles.

Provided herein are chimeric influenza hemagglutinin (HA) polypeptides, compositions comprising the same, vaccines comprising the same, and methods of their use.

The present invention provides, among other things, a novel and improved method for generating mosaic influenza antigenic polypeptides including hemagglutinin (HA) and neuraminidase (NA) polypeptides based on unique combination of epitope patterns that maximize exposure to epitopes present across multiple HA or NA sequences and therefore improved influenza strain coverage. In particular, the present invention provides engineered H1N1 influenza hemagglutinin (HA) polypeptides that are comprised of novel combinations of protective epitopes and antigenic regions from multiple H1N1 viral strains. Such engineered HA polypeptides have improved properties over HA polypeptides developed through conventional approaches that rely on consensus alignments of viral sequences.