Optimization of viral protein ratios for production of rAAV serotype 5 in the baculovirus system

Gene Ther. 2018 Sep;25(6):415-424. doi: 10.1038/s41434-018-0034-7. Epub 2018 Aug 1.

Abstract

Recombinant adeno-associated virus (rAAV) has become the vector of choice for the development of novel human gene therapies. High-yield manufacturing of high-quality vectors can be achieved using the baculovirus expression vector system. However, efficient production of rAAV in this insect cell-based system requires a genetic redesign of the viral protein 1 (VP1) operon. In this study, we generated a library of rationally designed rAAV serotype 5 variants with modulations in the translation-initiation region of VP1 and investigated the potency of the resulting vectors. We found that the initiation strength at the VP1 translational start had downstream effects on the VP2/VP3 ratio. Excessive incorporation of VP3 into a vector type decreased potency, even when the VP1/VP2 ratio was in balance. Finally, we successfully generated a potent rAAV vector based on serotype 5 with a balanced VP1/VP2/VP3 stoichiometry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Baculoviridae / genetics
  • Capsid Proteins / genetics
  • Genetic Therapy*
  • Genetic Vectors / genetics*
  • Genetic Vectors / therapeutic use
  • Humans
  • Operon / genetics
  • Parvovirinae / genetics*
  • Serogroup
  • Viral Proteins / genetics*
  • Viral Proteins / therapeutic use

Substances

  • Capsid Proteins
  • Viral Proteins

Supplementary concepts

  • Adeno-associated virus-5