Facing the Challenges in Vaccine Upstream Bioprocessing * Scalable Production of AAV Vectors We generated and purified both vectors in AAV9 trans-splicing and efficiency and expression levels were tested in vitro and in vivo. Following 72-hours transduction in HEK-293 cells by AAV9 virus (Figure 2), GFP expression was detectable in approximately 70% of cells, about 50% when compared to single vector GFP expression. Similar efficiency and expression levels were observed in RGC neurons, following two-week intraocular injection. A deeper understanding of the molecular basis for inherited and acquired diseases continues to drive the broader adoption of AAV as the vector of choice for treating many diseases. Numerous Phase I and II trials utilizing AAV have been performed for various inherited and acquired diseases. A continuation to greatly increase AAV vector yield, improve AAV potency and purity, and increase payload size will further make AAV a bigger player in gene therapy. n 14 | GENengnews.com Figure 2. Trans-splicing AAV vector expression of GFP in vitro and in vivo. Eva Szarek, Ph.D., is scientific marketing and sales manager Jeffrey Hung, Ph.D. (jhung@vigenebio.com), is chief commercial officer and GM of cGMP business at ViGene Biosciences.http://www.GENengnews.com