Lentiviral (LV) vectors are excellent gene delivery vehicles for cell and gene therapy applications. Traditionally, adherent HEK 293T cells are transiently transfected with second or third generation vectors to generate LV particles. Although this approach adequately serves the need for preclinical research, when scaling up to produce clinical or commercial GMP grade vectors, challenges arise due to the inherent limitations of adherent cells. While production has been historically scaled up with adherent 293T using multi-stack cell culture flasks or hollow fiber systems, these approaches are neither cost-effective nor operationally efficient for large scale production.
To overcome these challenges and facilitate large scale production of GMP-grade LV, our team at Theragent Inc. adapted adherent 293T cells (ATCC) to suspension culture using serum-free lentiviral production medium (SFM). The resulting adapted 293T suspension cells produced lentiviral titers that are comparable or superior to commercial lentiviral production cells under different conditions. Additionally, we optimized production conditions to obviate the requirement of commercial transfection reagents, enhancers, supplements, and packaging plasmids, saving both time and resources. Finally, we validated this cell line for production of LV encoding chimeric antigen receptors (CAR) and fluorescent protein. Currently, Theragent offers high titer RUO grade LV production service using this cell line to accelerate cell and gene therapy endeavors of academic labs and advanced therapy development companies.