Abstract

DNA vaccination and gene therapy using plasmid DNA [pDNA] are emerging as the tools of choice for preventing and treating debilitating diseases. A crucial issue in manufacturing pharmaceutical grade pDNA is quality control to fulfill the requirements of regulatory agency for purity, potency, safety and efficacy. Among the criteria that pDNA used for vaccination needs to meet, in full integrity of the DNA sequence to be injected. To control this parameter, a number of validated analytical methods are currently available. In this paper, we describe the molecular biology techniques used to control the quality and integrity of a hepatitis B DNA vaccine plasmid gWizHBs. To carry out this work, we have sequentially propagated gWizHBs in Escherichia coliDH5α and analyzed the plasmid preparation, by agarose gel electrophoresis, DNA restriction profiling and DNA sequencing. In addition to this generic technical platform, we have also discussed the limitation of the current DNA sequencing technique used in quality control of plasmid DNA for vaccination and suggest the use of pyrosequencing as a surrogate to Sanger DNA sequencing technique in order tocontrol pDNA-based vaccines. The quality of the DNA vaccine met the requirements for medical use.

Keywords: plasmid DNA [pDNA], gWizHBs, vaccines.