Type I interferon protects neurons from prions in in vivo models

Ishibashi, Daisuke; Homma, Takujiro; Nakagaki, Takehiro; Fuse, Takayuki; Sano, Kazunori; Satoh, Katsuya; Mori, Tsuyoshi; Atarashi, Ryuichiro; Nishida, Noriyuki

As lentiviral vectors were intracerebrally or stereotaxically administered on the ipsilateral side at 3 weeks after the intracerebral injection of 1% 22 L prion brain homogenate injection in Tga20 mice. The volume of the lentivirus via intracerebral injection was 20 ml (viral titer: 1.5 Â 10 8 IFU/ml). The volume of the lentivirus via stereotaxic microinjection was 4 ml (viral titer: 1.5 Â 10 8 IFU/ml). The flow rate was 1 ml/min, using automicroinjector-equipped Hamilton syringe 700 series (Narishige) (10 ml), and mounting a 30 gauge needle on the left hemisphere brain (thalamus coordinates: + 2 mm anterior to bregma, + 1 mm lateral to the midline and + 4 mm ventral form the skull surface). Lentivirus coding the Venus gene vector (LV-venus) was used as a control. To confirm gene expression by the lentiviral vector, the fluorescent Venus protein was visualized in mice brain tissues 3 weeks after viral inoculation using the confocal laser-scanning microscope LSM 700 (Carl Zeiss). Nuclei were stained with VECTASHIELD mounting medium containing DAPI (Vector Laboratories).