Abstract: Presented are ways to address the problem of replication competent adenovirus in adenoviral production for use with, for example, gene therapy. Packaging cells having no overlapping sequences with a selected vector and are suited for large scale production of recombinant adenoviruses. A system for use with the invention produces adenovirus incapable of replicating. The system includes a primary cell containing a nucleic acid based on or derived from adenovirus and an isolated recombinant nucleic acid molecule for transfer into the primary cell. The isolated recombinant nucleic acid molecule is based on or derived from an adenovirus, and further has at least one functional encapsidating signal, and at least one functional Inverted Terminal Repeat. The isolated recombinant nucleic acid molecule lacks overlapping sequences with the nucleic acid of the cell.

Abstract: A method is described for preparing primate bone marrow cells containing a DNA sequence of interest the method being first the isolation of bone marrow cells from a primate and then co-culturing the bone marrow cells with retrovirus producer cells. The retrovirus contains the DNA sequence of interest and infects the bone marrow cells during co-culture. To obtain bone marrow cells that contain the DNA sequence of interest, non-adherent bone marrow cells and adherent cells are harvested.