Abstract: Chimeric proteins that comprise one or more amino acid sequences of an insect-specific flavivirus and one or more other immunogenic proteins are provided. The chimeric proteins are suitably capable of forming virus particles. The chimeric protein and/or virus particle may be suitable for delivery to a subject to elicit an immune response to a pathogen and/or for diagnosis or detection of a pathogen. Also provided are nucleic acids and vectors encoding the chimeric proteins, and isolated chimeric insect-specific flaviviruses comprising the chimeric proteins and/or nucleic acids.

Abstract: Chimeric proteins that comprise one or more amino acid sequences of an insect-specific flavivirus and one or more other immunogenic proteins are provided. The chimeric proteins are suitably capable of forming virus particles. The chimeric protein and/or virus particle may be suitable for delivery to a subject to elicit an immune response to a pathogen and/or for diagnosis or detection of a pathogen. Also provided are nucleic acids and vectors encoding the chimeric proteins, and isolated chimeric insect-specific flaviviruses comprising the chimeric proteins and/or nucleic acids.

Abstract: A flaviviral replicon-based construct is provided for delivery and expression of granulocyte-macrophage colony stimulating factor to facilitate tumour therapy. In particular, the replicon construct encodes a Kunjin virus replicon having one or more mutations in an NS2A non-structural protein that induce enhanced levels of cellular IFN that synergize with recombinant granulocyte-macrophage colony stimulating factor delivered according to the invention. The construct may be administered intra-tumourally or peri-tumourally to an animal as DNA, RNA or packaged into a VLP, for the therapeutic and/or prophylactic treatment of tumours and cancers such as melanoma, lung carcinoma, cervical carcinoma, lung epithelial carcinoma, prostate cancer, breast cancer, renal carcinoma, colon cancer, epithelial cancers and mesothelioma.

Abstract: A vaccine composition and method of administering same is provided that utilizes an isolated nucleic acid corresponding to substantially an entire Kunjin virus which upon administration to an animal is capable of eliciting a protective immune response to another, more pathogenic flavivirus such as West Nile virus NY 99 strain. The isolated nucleic acid may further encode at least one attenuating mutation in a Kunjin virus structural and/or non-structural protein. The isolated nucleic acid may be in the form of DNA linked to a promoter in a plasmid construct for expression in vivo or may be in the form of naked RNA or RNA packaged into VLPs. The composition and method may provide protective immunization of animals such as humans, equines and avians.

Abstract: A tetracycline regulatable flaviviral packaging system is provided that facilitates expression of flaviviral structural proteins necessary for flaviviral RNA replicon packaging and virus like particle production in animal cells. This regulatable packaging system is compatible with Kunjin, Dengue and West Nile virus and other flaviviral replicon-based expression systems and produces unexpectedly high titres of virus-like particles. A particular application of this packaging system is the production of virus-like particles that package RNA comprising a flaviviral replicon and encoding a heterologous protein or peptide for expression in animal cells. Even more particularly, the packaging system is capable of delivering immunogens that induce a protective CD8 T cell-mediated immune response.

Abstract: A flaviviral expression vector, construct and system are provided that each comprise a flaviviral replicon that faciliates intracellular self-replication leading to high-level expression of RNA and protein(s) encoded by a heterologous nucleic acid. The flaviviral expression vector, construct and system preferably use a Kunjin virus replicon and are of particular use as a vaccine delivery system that facilitates expression of immunogenic proteins and peptides that induce protective T cell immunity to viral infections and cancer. Vaccines may be administered in the form of DNA, RNA or virus like particles.

Abstract: The present invention provides a gene expression system comprising: a) a self-replicating expression vector of flavivirus origin which includes the flavivirus 5? untranslated region (UTR), at least a portion of the 5? coding region for flavivirus core protein, the nucleotide sequence coding for the flavivirus non-structural proteins, and the complete or most of the 3?-terminal sequence of the flavivirus 3? UTR, required for self-replication of flavivirus genomic material, which vector is adapted to receive at least a nucleotide sequence without disrupting its replication capabilities; and b) at least a second vector that is capable of expressing flavivirus structural protein(s) and any other proteins required for packaging of the self-replicating expression vector into flavivirus viral particles which vector is engineered to prevent recombination with the self-replicating vector when in its presence.

Abstract: The present invention provides a gene expression system comprising: a) a self-replicating expression vector of flavivirus origin which includes the flavivirus 5? untranslated region (UTR), at least a portion of the 5? coding region for flavivirus core protein, the nucleotide sequence coding for the flavivirus non-structural proteins, and the complete or most of the 3?-terminal sequence of the flavivrus 3?UTR, required for self-replication of flavivirus genomic material, which vector is adapted to receive at least a nucleotide sequence without disrupting its replication capabilities; and b) at least a second vector that is capable of expressing flavivirus structural protein(s) and any other proteins required for packaging of the self-replicating expression vector into flavivirus viral particles which vector is engineered to prevent recombination with the self-replicating vector when in its presence.