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Biology subjects

Slavcev, R.

Publications and source records attributed to Slavcev, R..

2 recordsLinked to original sources

An E. coli-based platform for the production and assembly of anellovirus vectors

Gene therapy offers immense potential for treating various diseases, including cancer, immunodeficiencies, and cardiovascular conditions. The efficacy of gene therapy (GT) largely depends on the vector used for gene delivery. Viral vectors, while effective, pose risks including insertional mutagenesis, immune responses, and high manufacturing costs. Non-viral vectors, although safer and easier to produce, often exhibit lower transfection efficiency and weaker transgene expression. This highlights the need for novel, more efficient vectors. Among emerging strategies, bacteriophages are gaining attention as promising GT delivery vehicles due to their adaptability and safety profile. Filamentous phages like M13 have demonstrated potential as targeted gene delivery vectors. This study proposes constructing a single-stranded DNA (ssDNA) phage-based vector incorporating a eukaryotic gene cassette. By leveraging Ff phage replication mechanisms in E. coli, the study explores encapsidating ssDNA within anellovirus capsids. These small, ssDNA viruses, known for their ability to transfect diverse tissues, offer a safer alternative to conventional viral vectors. Through successful expression and assembly of anellovirus capsid proteins, ssDNA viral particles were produced ex vivo. This innovative E. coli-based anellovirus-phagemid system provides a promising, cost-effective platform for developing next-generation viral vectors in gene therapy.

molecular biology↗

Manufacturing DNA in E. coli yields higher fidelity DNA than in vitro enzymatic synthesis

The rise of biotechnologies such as gene therapy have brought DNA vectors to the forefront of pharmaceutical development. The quality of the genetic starting material plays a pivotal role in determining the quality of the final product. In this study we examined the fidelity of DNA replication using enzymatic methods (in vitro) compared to plasmid DNA produced in vivo in E. coli. Next-generation sequencing approaches predominantly rely on in vitro polymerases, which have inherent limitations in sensitivity. To address this challenge, we introduce a novel assay based on loss-of-function (LOF) mutations in the conditionally toxic sacB gene. Our findings show that DNA production in E. coli results in significantly fewer LOF mutations (approximately 80-to 3000-fold less) compared to various enzymatic DNA synthesis methods. This includes the most accurate PCR polymerase (Q5) and a commonly employed rolling circle amplification (RCA) DNA polymerase (Phi29). These results suggest that using low-fidelity starting material DNA synthesized in vitro by PCR or RCA may introduce a substantial number of impurities, potentially affecting the quality and yield of final pharmaceutical products. In summary, our study underscores that DNA synthesized in vitro has a significantly higher mutation rate than DNA produced traditionally in E. coli. Therefore, utilizing in vitro enzymatically-produced DNA in biotechnology and biomanufacturing may entail considerable fidelity-related risks, while DNA starting material derived from E. coli substantially mitigates this risk, enhancing overall quality in the production processes.

synthetic biology↗