Intracellular trafficking of nucleic acids

The intracellular transport of plasmid DNA, in the context of gene delivery by transfection using non-viral vectors, is still poorly explored. Relatively little is known about the kinetics and fate of the transfected DNA, such as its intracellular transfer and localization. A variety of intracellular barriers must be overcome to deliver exogenous DNA into the cell nucleus of the host cell to allow its expression. Vectors must cross the plasma membrane, move through the cytoplasm, enter the nucleus, and then locate to a specific site suitable for vector integration and DNA transcription. Intracellular movement of plasmid DNA complexes affecting gene delivery may represent one of the major barriers, and remains to be explored. Although genomic DNA is locally constrained, showing only very limited diffusion in interphase nuclei of living cells, little is known about the intranuclear dynamics and localization of small circular DNA molecules that invade cells as a result of virus infection, during gene therapy or experimental cell transfection.