Genetic manipulation of primitive leukemic and normal hematopoietic cells using a novel method of adenovirus-mediated gene transfer

Gene transfer into early hematopoietic cells has been problematic due to th e quiescent nature of primitive cells and the lack of gene transfer vehicle s with high efficiency for hematopoietic cell types. Previously, we have sh own that adenoviral vectors can be used for the transduction of normal huma n progenitors with gene transfer efficiencies of approximately 30%. However , this approach is limited by relatively slow uptake kinetics (24-48 h) and a strong dependence on the presence of exogenous cytokines. Thus, we have modified this approach by combining adenoviral vectors with polycations to generate a virus-polycation complex, or VPC. Vehicles of this nature, when composed of conventional adenoviral vectors and polyamidoamine dendrimers, are a highly efficient means of transducing both normal and acute myelogeno us leukemia (AML) cells. Moreover, the kinetics of gene transfer are marked ly increased using the VPC strategy, with approximately 70% of transduction complete within 2 h. In this study, using viruses that encode green fluore scence protein (GFP), or the T cell costimulatory molecule B7.1 (CD80), we show that VPC-mediated gene transfer is an effective means of transducing n ormal and AML cells, including those with a highly primitive phenotype. Our data suggest that transient genetic manipulation of primitive hematopoieti c cells can readily be achieved and should therefore permit a variety of re search and clinical endeavors.