Plasmid DNA fermentation strain and process-specific effects on vector yield, quality, and transgene expression.

Area of Science:

• Biotechnology
• Molecular Biology
• Genetic Engineering

Background:

• Industrial plasmid DNA manufacturing requires scalable, economical, and high-quality processes for gene therapy and vaccination vectors.
• Current methods face challenges in optimizing yield and ensuring product efficacy and safety.

Purpose of the Study:

• To develop enhanced plasmid DNA manufacturing processes for increased yields and improved vector characteristics.
• To investigate the impact of fermentation parameters and DNA methylation on plasmid production and performance.

Main Methods:

• Modified plasmid fermentation copy number induction profiles were developed to maximize vector yields.
• The effect of acetate byproduct on plasmid replication was assessed.
• The influence of epigenetic dcm methylase-directed cytosine methylation on plasmid production, transgene expression, and immunogenicity was investigated using dcm- strains.

Main Results:

• A modified induction profile increased gene therapy vector yields to 2,600 mg/L.
• Acetate secretion had a minimal negative impact on plasmid replication.
• dcm- strains showed increased transgene expression in human cells and reduced immunogenicity compared to methylated plasmids.
• Plasmid production yield and quality were unaffected by dcm- status in E. coli.

Conclusions:

• Optimized fermentation strategies and dcm- strains significantly enhance plasmid DNA production for gene therapy and related applications.
• dcm- plasmid DNA demonstrates superior performance in terms of transgene expression and reduced immunogenicity.
• Selecting the appropriate production strain with a locked methylation pattern early in development is crucial for successful gene therapy vector manufacturing.