title: Recombinant adeno-associated virus for the generation of autologous, gene-modified tumor vaccines: evidence for a high transduction efficiency into primary epithelial cancer cells.
abstract: To explore the potential of recombinant vectors based on recombinant adeno-associated virus (rAAV) for cancer vaccination, we investigated the transduction efficiency of rAAV into cancer cells ex vivo. Infection of human epithelial cancer cell lines with rAAV carrying reporter genes encoding beta-galactosidase (rAAV/LacZ) or luciferase (rAAV/Luc) resulted in high levels of reporter gene expression (>90% positive cells). In marked contrast, rAAV poorly transduced all murine tumor cell lines, as well as human hematopoietic cell lines. Either irradiation or adenovirus infection of tumor cells prior to rAAV infection induced a 10- to 100-fold increase of reporter gene expression. To determine the transduction efficiency of rAAV into primary cancer cells, freshly isolated, irradiated tumor cells from malignant melanoma and ovarian carcinoma patients were infected with rAAV/Luc, resulting in up to 6.9-fold higher levels of gene expression than in a HeLa tumor cell line. Time course experiments with freshly isolated tumor cells infected with rAAV/Luc showed maximal levels of luciferase expression between days 3 and 9 posttransduction. Simultaneous infection of primary tumor cells with up to three rAAV vectors containing genes encoding the immunostimulatory proteins B7-2 (CD86), p35 subunit of IL-12, and p40 subunit of IL-12 resulted in high expression of B7-2 in more than 90% of the tumor cells and in the secretion of high levels of IL-12. Taken together, our results demonstrate that rAAV efficiently transduces freshly isolated human, epithelial tumor cells and might therefore be a potent tool to produce improved, gene-modified cancer vaccines.
authors.affiliation: MediGene AG, Martinsried/Munich, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Maass
authors.forename: C
authors.initials: C
authors.lastname: Bogedain
authors.forename: U
authors.initials: U
authors.lastname: Scheer
authors.forename: D
authors.initials: D
authors.lastname: Michl
authors.forename: M
authors.initials: M
authors.lastname: Hörer
authors.forename: M
authors.initials: M
authors.lastname: Braun-Falco
authors.forename: M
authors.initials: M
authors.lastname: Volkenandt
authors.forename: D
authors.initials: D
authors.lastname: Schadendorf
authors.forename: C M
authors.initials: CM
authors.lastname: Wendtner
authors.forename: E L
authors.initials: EL
authors.lastname: Winnacker
authors.forename: R M
authors.initials: RM
authors.lastname: Kotin
authors.forename: M
authors.initials: M
authors.lastname: Hallek
mesh_terms: D015703:Antigens, CD / Q000235:genetics; D051940:B7-2 Antigen; D019496:Cancer Vaccines; D000229:Dependovirus; D004847:Epithelial Cells / Q000378:metabolism*; D005260:Female; D018014:Gene Transfer Techniques; D019073:HT29 Cells; D006367:HeLa Cells; D006801:Humans; D008545:Melanoma; D008562:Membrane Glycoproteins / Q000235:genetics; D010051:Ovarian Neoplasms; D011995:Recombination, Genetic; D014407:Tumor Cells, Cultured; D014965:X-Rays
chemical_list: D015703:Antigens, CD; D051940:B7-2 Antigen; C497964:CD86 protein, human; D019496:Cancer Vaccines; D008562:Membrane Glycoproteins