To generate lentivirus supernatant, HEK-293FT packaging cells (3.75 × 106 293TN cells per 10 cm plate) were transfected with the vectors, along with the pPACKF1TM Lentiviral Packaging Kit using lipofectamine reagent and plus reagent (Invitrogen) according to the manufacturer's instructions. Medium containing virus particles (~10 ml) was harvested 48–60 h post-transfection by centrifugation at 76,755g at room temperature for 5 min to pellet cell debris and filtered through 0.45 mm PVDF filters (Millex-HV). To concentrate the viral supernatant for intrastriatal administration, supernatants were centrifuged at 32,000g for 90 min at 4 °C, and the precipitate re-suspended in 100 μl cold PBS. Supernatants were aliquoted into 10 ml volumes and stored at −80 °C until use.
