Purification of a cystic fibrosis plasmid vector for gene therapy using hydrophobic interaction chromatography

• Published in: Biotechnology and bioengineering 2000-06, Vol.68 (5), p.576-583
• Main Authors: Diogo, M. M., Queiroz, J. A., Monteiro, G. A., Martins, S. A. M., Ferreira, G. N. M., Prazeres, D. M. F.
• Format: Article
• Language: English
• Subjects: Ammonium compounds; Chromatography - methods; Chromatography, High Pressure Liquid; cystic fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator - genetics; Cystic Fibrosis Transmembrane Conductance Regulator - isolation & purification; DNA; Endotoxins - analysis; Escherichia coli - chemistry; Escherichia coli - genetics; gene therapy; Genetic Therapy - methods; Genetic Vectors - isolation & purification; Humans; Hydrophobic chromatography; hydrophobic interaction chromatography; nucleic acids; plasmid purification; Plasmids - genetics; Precipitation (chemical); Purification; Quality Control; RNA
• ISSN: 0006-3592; 1097-0290
• DOI: 10.1002/(SICI)1097-0290(20000605)68:5<576::AID-BIT13>3.0.CO;2-5

The success and validity of gene therapy and DNA vaccination in in vivo experiments and human clinical trials depend on the ability to produce large amounts of plasmid DNA according to defined specifications. A new method is described for the purification of a cystic fibrosis plasmid vector (pCF1‐CFTR) of clinical grade, which includes an ammonium sulfate precipitation followed by hydrophobic interaction chromatography (HIC) using a Sepharose gel derivatized with 1,4‐butanediol‐diglycidylether. The use of HIC took advantage of the more hydrophobic character of single‐stranded nucleic acid impurities as compared with double‐stranded plasmid DNA. RNA, denatured genomic and plasmid DNAs, with large stretches of single strands, and lipopolysaccharides (LPS) that are more hydrophobic than supercoiled plasmid, were retained and separated from nonbinding plasmid DNA in a 14‐cm HIC column. Anion‐exchange HPLC analysis proved that >70% of the loaded plasmid was recovered after HIC. RNA and denatured plasmid in the final plasmid preparation were undetectable by agarose electrophoresis. Other impurities, such as host genomic DNA and LPS, were reduced to residual values with the HIC column (