A recombinant virus containing a degron, a preparation method therefor, and an application thereof. At least one viral protein of the recombinant virus containing the degron contains at least one degron capable of being recognized by a protein degradation system of a host cell, wherein the degron comprises any one of or a combination of at least two of an amino acid sequence, a polypeptide, or a structural motif. Further provided are a nucleic acid molecule, a recombinant vector, a preparation method for the recombinant virus containing the degron, a preparation system for the recombinant virus containing the degron, a vaccine, an oncolytic virus, and a drug. The recombinant virus containing the degron can be recognized and degraded by the protein degradation system in the host cell, the replication capability is weakened or even removed, and after a corresponding vaccine, oncolytic virus or drug is prepared, a good effect and practical application value are achieved.

The present invention relates to a novel MDCK-derived cell line capable of being suspension-cultured in a protein-free medium and a method for proliferating a virus using the MDCK-derived cell line to produce a vaccine. The novel MDCK-derived cell line exhibits high and uniform productivity for various viruses, while causing less viral antigenic variations with low tumorigenicity, and thus can be useful in producing viruses used for vaccines.

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.

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.

Production of modified influenza viral proteins in plants is described. More specifically, producing and increasing influenza virus-like particle (VLP) production in plants, wherein the VLPs comprise the modified influenza viral proteins, such as modified influenza hemagglutinin (HA) is described. The HA protein may comprise an amino acid sequence comprising at least one substitution when compared to a corresponding wildtype amino acid sequence. Further provided are nucleic acids encoding the modified HA protein. Furthermore, methods of producing an influenza virus like particle (VLP) and methods of increasing yield of production of an influenza virus like particle (VLP) in a plant, portion of a plant, or a plant cell, are also provided.

The present invention provides genetically modified cells useful for viral replication and the production of viral vaccines.

The present invention includes influenza Hemagglutinin protein fragments that fold properly when expressed in bacteria.

Disclosed herein are compositions and methods related to mutant viruses, and in particular, mutant influenza viruses. The mutant viruses disclosed herein include a mutant M2 sequence, and are useful in immunogenic compositions, e.g., as vaccines. The mutant viruses disclosed herein including a mutant M2 sequence are also useful to deliver antigens to a subject, e.g., to induce an immune response to the antigen. Also disclosed herein are methods, compositions and cells for propagating the viral mutants, and methods, devices and compositions related to vaccination.

The present invention describes a viral RNA expression plasmid and a method for obtaining viral particles based on said plasmids comprising transfecting animal cells with an expression vector or a set of expression vectors capable of expressing a nucleoprotein and RNA-dependent polymerase RNA; and transfecting the animal cell with an expression vector or a set of expression vectors with nucleotide sequences encoding recombinant RNA molecules.

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.