High-Yield Recombinant Adeno-Associated Virus Production Using a Novel
Transfection Reagent
Abstract
Recombinant adeno-associated viruses are a promising gene therapy, with
several therapeutics on the market in the United States. As we continue
to industrialize manufacturing of these viral vectors, we strive to
improve productivity and yield. To this end, we investigated a novel
transfection reagent to improve the genomic titer of adeno-associated
virus 8. Using a miniaturized automated 250 mL scale bioreactor system,
we generated models of genomic and capsid titer from two multivariate
design of experiments; one centered around bioprocess conditions, and
another based on the transfection conditions. Using the optimized
setpoints returned from these models, we improved our viral genome titer
out of the bioreactor to beyond 1 × 10 12 vg/mL; to
our knowledge the highest genomic titer reported from an upstream
process utilizing HEK293 cells. When we applied these setpoints to six
serotypes carrying a unique viral payload, five of the six returned
higher genomic titers than the control condition, but were all below the
titer of the vector used in our optimization studies. These data suggest
that the choice of transfection reagent is a major factor in viral titer
and percent full capsids, and that transfection conditions are serotype
and payload specific.