361. Metallic Particles Generated During Electric Pulses Enhance Adenovirus-Mediated Gene Transfer

Abstract

In vitro and in vivo gene transfer into cells and tissues using electric pulse application is more and more attractive due to its safety, versatility and efficiency improvement of protocols. However, the DNA penetration across the plasmic membrane during electrotransfer is not fully understood, and even large uncertainties remain about which mechanism(s) are actually involved. To learn more about the process(es) implicated for another large molecular object, we have applied electric pulses during recombinant adenovirus infection of cells in suspension.We observed an important increase of recombinant adenovirus-mediated GFP gene transfer when low voltage millisecond pulses were applied on poorly adenovirus-infectable cells. High quantities of metallic particles generated from the electrodes during this type of electropulsation were probably responsible of the observed effect. Indeed, if infection solution is pulsed separately and later on added to the cells, the same increase in adenovirus-mediated transfer is observed. Moreover, at a given multiplicity of infection of the virus, the effect is proportional to the quantities of metallic particles generated. After centrifugation of the pulsed infection solution, the virus was found mainly associated with metallic particles in the pellet. We are currently investigating the structure of adenovirus/metallic particle complex and the process involved in the enhancement of adenovirus entry into cells.