SYSTEMIC GENE-EXPRESSION AFTER INTRAVENOUS DNA DELIVERY INTO ADULT MICE

Direct gene transfer into adult animals resulting in generalized or ti ssue-specific expression would facilitate rapid analysis of transgene effects and allow precise in vivo manipulation of biologic processes a t the molecular level. A single intravenous injection of expression pl asmid:cationic liposome complexes into adult mice efficiently transfec ted virtually all tissues. In addition to vascular endothelial cells, most of the extravascular parenchymal cells present in many tissues in cluding the lung, spleen, lymph nodes, and bone marrow expressed the t ransgene without any apparent treatment-related toxicity. The transgen e was still expressed in large numbers of cells in multiple tissues fo r at least 9 weeks after a single injection. Expression could be targe ted to specific tissues and cell types, depending on the promoter elem ent used.