Gene delivery systems to phagocytic antigen-presenting cells

Gene delivery to professional antigen presenting cells (APCs) offers great potential for the immunotherapy of infectious diseases, cancer and for tole rance. Synthetic gene delivery systems have thus emerged as a promising tec hnology to circumvent safety concerns affecting life vectors. Various gene delivery systems including liposomes, cationic polymers and biodegradable m icrospheres were tested for their gene transfer efficiency in APCs. While c omplexes of liposomes and cationic polymers, with DNA are efficiently able to transfect model cell lines in vitro, transfection of APCs was very poor. Microparticulate delivery systems can be used to selectively large phagocy tic APCs such as macrophages and dendritic cells, Biodegradable microsphere s delivery encapsulated DNA to phagocytic APCs in large quantities and DNA is released inside the cells upon biodegradation of the microspheres. Howev er, gene expression is very low and may be restricted by phagolysosomal ent rapment of the the DNA.