A COMPARISON OF GENE-TRANSFER METHODS IN HUMAN DENDRITIC CELLS

Dendritic cells (DCs) are the most potent antigen-presenting cells (AP Cs) for the initiation of antigen-specific T-cell activation. DCs may be highly enriched from peripheral blood-adherent leukocytes by short- term (7-day) culture in the presence of interleukin (IL)-4 and granulo cyte-macrophage colony-stimulating factor. Various methods of gene tra nsfer were studied, including DNA/liposome complexes, electroporation, CaPO4 precipitation, and recombinant adenovirus (AdV) vectors. Low le vels of expression were obtained with the physical methods tested. In contrast, AdV vectors expressing luciferase, beta-galactosidase, IL-2, and IL-7 all readily transduced human DCs. Increasing levels of gene expression were observed over a range of multiplicity of infection (MO I) of 10:1 to 10,000:1, with transduction efficiencies exceeding 95% a t higher MOI. Although levels of maximal gene expression in DCs were s ignificantly lower than those obtained using human tumor cell lines, I L-2 and IL-7 production of up to 5 x 10(2) ng/10(6) DC were achieved. These results suggest that AdV vectors are a promising vehicle for gen etically engineering human DCs.