Establishment of a novel human amniotic epithelial-derived cell line, HAT, for high-yield AAV vector production

Gene therapy using adeno-associated virus (AAV) vectors has advanced remarkably in recent decades. However, efficient AAV vector production remains challenging despite extensive efforts to optimize the commonly used HEK293 cells. Here, we describe a novel host cell line tailored for AAV vector production. Human amniotic epithelial cell line for gene and cell therapy (HAT) was generated by introducing adenovirus type 5 E1 genes into primary cells isolated from placental amnion after cesarean section. HAT cells were adapted to suspension culture conditions in a serum-free, chemically defined medium and subsequently single-cell-cloned to support future industrial applications. HAT cells exhibited robust proliferation and AAV productivity. Quality assessments revealed that HAT-produced AAV2 and AAV8 vectors had overall product quality attributes comparable to those from HEK293 cells. They were characterized by efficient genome packaging and in vitro infectivity, with a notably higher proportion of full capsids. Furthermore, consistent yields and product quality attributes across shake flask and benchtop bioreactor production demonstrated good scalability in HAT cells. Together, these features indicate the potential of HAT cells to provide a host cell platform that will advance biopharmaceutical manufacturing.