A RECOMBINANT E1-DELETED CANINE ADENOVIRAL VECTOR CAPABLE OF TRANSDUCTION AND EXPRESSION OF A TRANSGENE IN HUMAN-DERIVED CELLS AND IN-VIVO

Human adenovirus (HAV) serotypes 2 and 5 are commonly used as vector b ackbones for adenovirus-mediated gene transfer, However, HAVs were cho sen as a backbone for the vectors for historical reasons and have a nu mber of significant disadvantages when used as a shuttle for gene tran sfer in humans, As an initial trial to circumvent some of the shortcom ings of HAV vectors, we have produced an E1-deleted canine adenovirus type 2 (CAV-2) vector for gene transfer, Initially, we demonstrated th at CAV-2 undergoes an abortive viral cycle in a wide range of human-de rived cell lines, Second, we assayed human sera containing HAV-5 neutr alizing antibodies for their ability to inhibit CAV-2-induced plaques on permissive cells, In the cohort tested, our data demonstrate that t he humoral response directed against HAV-5 does not inhibit CAV-2 plaq ue formation in the majority of cases. Canine cell lines expressing th e E1 region of CAV-2 were generated and characterized, A recombinant C AV vector (CAVRSV beta gal) deleted in the E1 region and harboring lac Z was constructed, We show that CAVRSV beta gal is able to transduce a nd direct expression of the transgene in vitro in a variety of mammali an cells, most notably primary human-derived cells, In addition, gene transfer is demonstrated in vivo using chick embryos.