461. Scale-Up and Manufacturing of High-Titer Foamy Virus Vector Containing Human CD18 for the Treatment of Leukocyte Adhesion Deficiency

Abstract

sequencing (NGS) technology. However, success of this approach depends on low prevalence of circulating antibodies against common AAV serotypes such as AAV2 and AAV9 because these serotypes serve as internal reference controls in this system. Therefore, it is essential to investigate the prevalence of neutralizing antibodies against various serotypes in cats for applying the AAV Barcode-Seq to preclinical studies and ultimately for successful translation of AAV vector-mediated gene therapy approaches into the veterinary clinic. Here we report the results of the initial screening of 30 cat serum samples obtained from the Liberty Research Inc. cat colony for the presence of antibodies against a total of 11 different AAV serotypes (AAV1 through 11). Such a study is imperative because a vaccine against feline panleukopenia virus (FPV), a feline parvovirus, is widely used to immunize cats and all the cats to be used for our study will have received that vaccine. In the study, serum samples were incubated in ELISA plates coated with serotype-specific particles followed by addition of an HRP-conjugated anti-cat IgG antibody. Anti-FPV antibody titers were determined by a hemagglutination inhibition test (Cornell University, Animal Health Diagnostic Center). The results showed that the majority of the 30 cats did not harbor any detectable antibodies against AAV1,

Progress and challenges in viral vector manufacturing

“…In addition, transfection with PEI only requires the addition of one reagent whereas CaPhos transfection requires the mixing of two components. Interestingly, in the production of foamy virus vectors, the use of PEI as compared with CaPhos significantly increased viral titer (58,59). Finally, the development of the MaxCyte, a scalable transfection system that uses flow electroporation, allows for the rapid transfection of large numbers of cells (104).…”