A method for synthesizing influenza virus-like particles (VLPs) within a plant or a portion of a plant is provided. The method involves expression of influenza HA in plants and the purification by size exclusion chromatography. The invention is also directed towards a VLP comprising influenza HA protein and plant lipids. The invention is also directed to a nucleic acid encoding influenza HA as well as vectors. The VLPs may be used to formulate influenza vaccines, or may be used to enrich existing vaccines.

The present invention is within the field of chromatography. More precisely, it relates to a novel chromatography medium, namely a hydrophobic medium provided with different lids excluding molecules over a certain size due to the porosity of the hydrophobic medium and/or the porosity of the lid. The invention also relates to use of the separation medium for purification of large molecules, which do not enter the separation medium, as well as small molecules, which enter the separation medium and are eluted from there.

In some embodiments the present invention provides influenza hemagglutinin (“HA”) polypeptides, proteins, and protein complexes that comprise a stalk domain that is engineered to facilitate maintenance of its native trimeric conformation, even if the head domain of the HA protein is removed or disrupted. In some embodiments, the present invention provides compositions comprising such polypeptides, proteins, and protein complexes, and methods of use of such proteins and compositions, for example as vaccine immunogens.

The invention provides a recombinant biologically contained influenza virus that is a PB2 knockout virus, e.g., one that is useful to generate a multivalent vaccine, and methods of making and using that virus.

Provided are compounds that enhance the efficacy of viruses by increasing spread of the virus in cells, increasing the titer of virus in cells, or increasing the antigen expression from a virus, gene or trans-gene expression from a virus, or virus protein expression in cells. Other uses, compositions and methods of using same are also provided.

A method of increasing the yield, stability, or both of an acid sensitive protein 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 the acid sensitive 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 increasing the yield of the acid sensitive protein when compared to the yield of the acid sensitive protein produced in the plant or portion of the plant produced under the same conditions, and in the absence of the proton channel protein.

The invention provides an influenza virus that demonstrates enhanced growth in Vero cells. The influenza virus includes PB1, PB2, PA, NP, and NS gene segments encoding proteins having amino acid sequences with selected amino acids. Optionally, at least one of the PB1, PB2, and PA gene segments includes a cytosine to uracil promoter mutation at nucleotide position 4. The invention el also provides a pharmaceutical formulation containing the influenza virus, as well as a method of eliciting an immune response in a mammal by administering the influenza virus to the mammal, and a method for generating the influenza virus.

An isolated recombinant influenza virus is provided having PA, PB1, PB2, NP, NS, M, NA and HA viral segments, wherein the PB1 viral segment encodes a PB1 with a residue other than isoleucine at position 711 or the M viral segment encodes a M1 with a residue other than methionine at position 128, wherein the recombinant influenza virus has enhanced replication relative to a corresponding influenza virus having a PB1 viral segment that encodes a PB1 with an isoleucine at position 711 or having a M viral segment that encodes a M1 with methionine at position 128, as well as methods of making and using the virus.

The present invention relates to methods of replicating viruses in vitro. In particular, the invention relates to a genetically modified population of cells, and/or a population of cells treated with an exogenous compound, wherein the cells are capable of producing more virus than cells lacking the genetic modification and/or lacking treatment with the exogenous compound. The invention also relates to methods of producing populations of such cells, as well as the use of the viruses obtained to prepare vaccine compositions.

The subject invention pertains to isolated influenza virus that is capable of infecting canids and causing respiratory disease in the canid. The subject invention also pertains to compositions and methods for inducing an immune response against an influenza virus of the present invention. The subject invention also pertains to compositions and methods for identifying a virus of the invention and diagnosing infection of an animal with a virus of the invention.