US Patent 6872528 Highly productive packaging lines

The invention concerns a packaging eukaryotic cell for the production of defective infections viruses carrying a transgene, characterized in that it is deficient in one cell function essential to its growth, in particular in the presence of a selection culture medium, the function being capable of being restored by the expression of an exogenous sequence introduced in the cell: either with a vector carrying transcomplementing functions of packaging cells; or with a vector carrying a transgene, and enabling the selection in a selective medium of cells carrying the said exogenous sequence.