Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: This invention provides a method for making adenovirus cloning vectors which contain a recombinase target site that is useful for the insertion of selected foreign proteins.