The present invention relates to a genetically modified plant or plant cell derived from a wild-type plant or plant cell, said wild-type plant or plant cell producing at least one serine protease comprising the motif SSRGPX.sub.1LKPDX.sub.2X.sub.3APGX.sub.4SGTSMSCPHX.sub.5PX.sub.6WSPX.sub.7AX.sub.8X.sub.9SAX.sub.10MTT (SEQ ID No. 1), wherein

X.sub.1 is a peptide consisting of 7 amino acid residues, X.sub.2 is I or L, X.sub.3 is T or M, X.sub.4 is a peptide consisting of 27 or 28 amino acid residues, X.sub.5 is a peptide consisting of 12 amino acid residues, X.sub.6 is T or E, X.sub.7 is S or A, X.sub.8 is V or I, X.sub.9 is K or R and X.sub.10 is I or M, wherein the proteolytic activity of the at least one serine protease in the genetically modified plant or plant cell is reduced compared to its activity in the wild-type plant or plant cell, wherein the genetically modified plant or plant cell comprises at least one exogenous nucleic acid molecule encoding for at least one protein or polypeptide of interest.

Nucleic acids encoding rotavirus VP7 fusion proteins and rotavirus-like particle (RLPs) comprising the rotavirus VP7 fusion proteins are provided. Methods for rotavirus VP7 fusion protein and RLP production in plants are also described. The VP7 fusion protein comprises a first sequence encoding a 7-1a subdomain, a second sequence encoding a 7-2 domain and a third sequence encoding a 7-1b subdomain; wherein the sequence of the 7-2 domain is derived from a first rotavirus strain and the sequence of the 7-1a subdomain, the sequence of the 7-1b subdomain or the sequence of the 7-1a subdomain and the sequence of the 7-1b subdomain are derived from a second rotavirus strain.

This invention relates to a second generation, plant-produced synthetic Orbivirus candidate vaccine. The vaccine comprises a plant produced chimaeric Orbivirus virus like particle (VLP) comprising at least one structural protein from one Orbivirus serotype and at least one structural protein selected from another serotype of the Orbivirus, wherein both structural capsid proteins are from the same Orbivirus species. In particular the invention relates to a vaccine against an Orbivirus, a method of producing chimaeric Orbivirus virus-like particles (VLPs) for use in a method of prevention and/or treatment of an Orbivirus infection, the use of the chimaeric Orbivirus VLPs in the manufacture of a vaccine for an Orbivirus, and a method of preventing and/or treating an Orbivirus infection.

The present invention relates to the production of modified influenza viral proteins in plants. More specifically, the present invention relates to 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). The HA protein may comprising an amino acid sequence comprising at least one substitution when compared to a corresponding wildtype amino acid sequence. Further provided are nucleic acid 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.

Increased antigenicity of a membrane-bound polypeptide produced from a plant is provided in a process in which extraction of the polypeptide or other compounds from the plant is such that phospholipids are associated with the polypeptide. Reducing fat by supercritical fluid extraction increases antigenicity of such plant-produced membrane-bound polypeptides. Methods and means of producing such membrane-bound polypeptides are provided. Methods to produce a protective response in animals are provided by administering to the animal the membrane-bound polypeptide. Binding of antibody specific to the membrane-bound polypeptide is increased. The process provides for increased preferred formation of the membrane-bound polypeptide. Stability of the membrane-bound polypeptide is increased when the plant material is defatted.

The present invention provides a recombinant expression vector comprising a gene encoding canine parvovirus 2a VP2 or 2b VP2 protein, a recombinant plant into which the vector is transformed, a vaccine composition against canine parvovirus, comprising canine parvovirus 2a VP2 or 2b VP2 protein obtained from the recombinant plant, and a composition for diagnosing canine parvovirus. When the recombinant plant of the present invention is used, canine parvovirus 2a VP2 or 2b VP2 antigen protein can be rapidly produced with high efficiency. Since the composition for diagnosing canine parvovirus according to the present invention uses a recombinant antigen protein, there is no possibility of contamination due to live virus handling, and thus the composition is safe, and the presence or absence of canine parvovirus infection can be rapidly diagnosed from a large amount of samples.

An isolated expression enhancer active in a plant, portion of a plant or plant cell, the expression enhancer is provided. The isolated expression enhancer may be selected from the group consisting of nbEPI42 (SEQ ID NO:1); nbSNS46 (SEQ ID NO:2); nbCSY65 (SEQ ID NO:3); nbHEL40 (SEQ ID NO:4); and nbSEP44 (SEQ ID NO:5). Methods for using the isolated expression enhancer are also provided.

Methods for improving transgene in chloroplasts are disclosed along with improved transgenes so produced and methods of use thereof for the treatment of disease. Specifically, the methods comprising analyzing the native sequence of a nucleic acid encoding a protein of interest and replacing codons in said sequence with those preferentially used in psbA genes in chloroplasts in higher plants.

A method of producing a virus like particle (VLP) in a plant comprising modified H3 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. 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.

Plant T-DNA expression vectors with engineered 5′ sequences for driving transcription of genes encoding post-translational modification enzymes are provided. Also methods of optimizing expression and glycosylation of recombinant protein produced in plants by utilizing plant T-DNA expression vectors with engineered 5′ sequences for driving transcription of genes encoding post-translational modification enzymes.