Advec, Inc.

Merck + Co., Inc.

University of Saskatchewan

Veterinary Infectious Disease Organization

Frank L Graham

Robin Parks

Ludvik Prevec

Lorne A Babiuk

Michael A Rudnicki

Martina Anton

Suresh K Mittal

Philip Ng

Silvia Bacchetti

Ping Wang

William J Muller

Liane Chen

Suresh Kumar Tikoo

Suresh Kumar Mittal

Wael M Haddara

Andrew Bett

Methods, cells and recombinant adenoviral vectors are disclosed that permit the production of recombinant adenoviral vector stocks with reduced levels of contamination by replication competent adenoviruses (RCA). In certain embodiments are disclosed early region 1 (E1) deficient recombinant adenoviral vectors and complementing E1 positive host cells whose sequences are designed to avoid formation of RCA by homologous recombination between sequences in the vector and E1 sequences in the cells. One aspect of the invention involves the inversion of the packaging signal in a recombinant adenoviral vector relative to an adjacent or nearby inverted terminal repeat (ITR). Methods include use of site-specific intregrase family recombinases such as Cre or FLP and recombinase recognition sites such as lox sites or frt sites.

Production of adenovirus vectors with reduced levels of replication competent adenovirus contamination

The present invention relates to methods for efficient and reliable construction of adenovirus vectors which contain and express foreign DNA and are useful for gene transfer into mammalian cells, for vaccines and for gene therapy. The invention provides for the growth and purification of adenovirus vectors (helper dependent vectors or HDVs) from which all or most of the viral genes have been removed. The vector system described herein is a new method designed to eliminate helper viruses from the final HDV preparation by cleavage of the helper virus DNA with an endonuclease, alone or in combination with other methods known to limit the level of helper virus contamination of helper dependent vector preparations. The disclosed methods and compositions also provide for regulated control of gene expression.

System for production of helper dependent adenovirus vectors based on use of endonucleases

In the present invention, viruses, plasmids or both are constructed which contain viral DNA and lox sites positioned such that site-specific recombination between lox sites in separate plasmids results in generation of infectious viral DNA at high-efficiency in cotransfected host cells that have been engineered to express the Cre recombinase. Because of the high-efficiency and specificity of the Cre enzyme, suitably engineered plasmids can be readily recombined to produce infectious virus at high-efficiency in cotransfected 293 cells, without, at the same time, producing wild-type adenovirus, with the attendant problems for removal thereof. Use of recombinases besides Cre and recombinase recognition sites besides lox sites, and use of cells other than 293 cells are also disclosed and enabled, as are kits incorporating the site-specific vector system.

Recombinase-based system for combustion of adenovirus vectors

This invention provides helper-dependent adenovirus cloning vectors and helper adenoviruses, and methods for making and Using such preparations, wherein the helper adenoviruses contain recombinase target sites that are useful in reducing the level of contamination of helper virus in helper-dependent adenovirus vector preparations.

Helper dependent adenovirus vectors based on integrase family site-specific recombinases

The present invention relates novel live bovine adenovirus (BAV) expression vector systems in which part or all of one or both of the early region 1 (E1) and early region 3 (E3) genes are deleted and replaced by a foreign gene or fragment thereof and novel recombinant mammalian cell lines stably transformed with BAV E1 sequences, and therefore, express E1 gene products capable of allowing replication therein of a bovine adenovirus having an E1 deletion replaced by a heterologous nucleotide sequence encoding a foreign gene or fragment thereof and their use in production of (antigenic) polypeptides or fragments thereof for the purpose of live recombinant virus or subunit vaccine or for other therapies.

Recombinant protein production in bovine adenovirus expression vector system

The invention claims a class of adenovirus vectors for delivering recombinases to a large number of cells of different origins, and methods for regulating the expression of a gene in transfected mammalian cells in culture and in cells of transgenic animals, comprising infecting said cells with an Ad vector encoding a recombinase whose target site is present at or adjacent to the gene, wherein the action of the recombinase regulates the expression of said gene.

Adenoviruses for control of gene expression

In the present invention, viruses, plasmids or both are constructed which contain viral DNA, at least one head-to-head ITR junction, and recombinase recognition sites positioned such that site-specific recombination between recombinase recognition sites in separate plasmids results in generation of infectious viral DNA at high-efficiency in cotransfected host cells that have been engineered to express a site-specific recombinase. Because of the high-efficiency and specificity of the Cre enzyme, suitably engineered plasmids can be readily recombined to produce infectious virus at high-efficiency in cotransfected 293 cells, without, at the same time, producing wild-type adenovirus, with the attendant problems for removal thereof. Use of recombinases besides Cre and recombinase recognition sites besides lox sites, and use of cells other than 293 cells are also disclosed and enabled, as are kits incorporating the site-specific vector system, as well as compositions and methods for using such compositions as vaccines or in gene therapeutic applications. Enhancement in the efficiency of site-specific recombination is provided by inclusion of a head-to-head ITR junction in each virus, plasmid, or other nucleic acid construct.

Enhanced system for construction of adenovirus vectors

This invention responds to a long felt need, by providing in one embodiment, a helper virus based on the Ad2 serotype for use in the Cre/loxP system for the generation of Ad vectors deleted of all Ad protein coding sequences. Using this and helper virus based on Ad5, genetically identical hdAd that differ only in the virion protein components, which are derived from the helper virus, were produced. The vectors have identical expression characteristics in vitro, regardless of the serotype, and the sequential use of hdAd of different serotypes allows for successful repeat vector administration in vivo.

Use of helper-dependent adenoviral vectors of alternative serotypes permits repeat vector administration

The present invention provides an improved helper-dependent vector system for production of high capacity adenoviral cloning vectors. The invention makes use of the DNA size packaging constraints imposed on a pIX-defective Ad virion that prevent such virions from packaging DNA larger than approximately 35 kb. This constraint can be used to develop helper viruses that do not package their DNA. In one embodiment, the invention combines this methodology with the Cre-loxP helper-dependent system to decrease the quantity of contaminating helper virus in vector preparations. In another embodiment the invention is used for vector growth.

Adenovirus vectors generated from helper viruses and helper-dependent vectors

In the present invention, viruses, plasmids or both are constructed which contain viral DNA and lox sites positioned such that site-specific recombination between lox sites in separate plasmids results in generation of infectious viral DNA at high-efficiency in cotransfected host cells that have been engineered to express the Cre recombinase. Because of the high-efficiency and specificity of the Cre enzyme, suitably engineered plasmids can be readily recombined to produce infectious virus at high-efficiency in cotransfected 293 cells, without, at the same time, producing wild-type adenovirus, with the attendant problems for removal thereof. Use of recombinases besides Cre and recombinase recognition sites besides lox sites, and use of cells other than 293 cells are also disclosed and enabled, as are kits incorporating the site-specific vector system, as well as compositions and methods for using such compositions as vaccines or in gene therapeutic applications.

High-efficiency Cre/loxp based system for construction of adenovirus vectors

The present invention provides novel recombinant mammalian cell lines expressing bovine adenovirus functions. In one embodiment, mammalian cell lines stably transformed with bovine adenovirus E1 sequences express bovine adenovirus E1 gene products and are useful for the replication of bovine adenovirus vectors having deletions and/or insertions in the E1 region. Such vector/cell line combinations are useful for synthesis of recombinant polypeptides, preparation of subunit vaccines, and in gene therapy.

Mammalian cell lines expressing bovine adenovirus functions

The invention comprises a series of adenovirus-based vectors having deletions in the E1 and/or E3 regions, and also insertions of pBR322 sequences, which can be used to deliver nucleic acid inserts into host cells, tissues or organisms that then can express the insert. The invention includes the use of the vectors in introducing genes into cells, in making vaccines and in gene therapy.

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Rome, Italy

Frank L Graham