Fig. 2: In vivo base editing provides protection from pathogenic human prion challenge.
From: In vivo base editing extends lifespan of a humanized mouse model of prion disease
a, Design of the human pathogenic prion challenge study. Tg25109 mice were divided into two cohorts: a human prion isolate inoculation group and an uninoculated control group. Among the human prion isolate inoculation group, n = 13 received dual-AAV PHP.eB BE3.9max PRNP R37X treatment and n = 11 received dual-AAV PHP.eB BE3.9max Dnmt1 control treatment. Among the uninoculated control group, n = 5 received dual-AAV PHP.eB BE3.9max PRNP R37X treatment and n = 1 remained untreated. Mice were treated with AAV at total dose of 1 × 1014 vg kg−1 at age 6–9 weeks. At 1 week after AAV treatment, mice were inoculated with either E200K or sCJD prion isolates. After prion inoculation, mice were monitored for weight loss, nest-building behavior and lifespan. Study endpoint was 600 d post prion isolate inoculation (92–95 weeks of age). The uninoculated control group was euthanized to harvest brain hemispheres for analysis via HTS and PrP ELISA. b, Kaplan–Meier curve of Tg25109 mice inoculated with either the E200K (purple) or sCJD MM1 pathogenic human prion isolate (red). Median survival from each treatment condition is marked (P = 4 × 10−4 for sCJD-inoculated cohort; P = 0.01 for E200K cohort; P = 2 × 10−6 combined). c,d, Body weight (c) (lines represent mean and shaded areas represent 95% CI) for all timepoints with ≥2 animals surviving, and nest-building score (d) (fitted to the locally estimated scatterplot smoothing (LOESS) model) of Tg25109 mice in the human prion challenge study. e,f, Frequency of the desired R37X edit (e) (P < 0.0001) and indels, and PrP protein level (f) (P < 0.0001) in the bulk brain hemisphere of mice from the uninoculated control group treated with dual-AAV PHP.eB BE3.9max with PRNP R37X sgRNA (n = 5), and in untreated mice from the uninoculated control group (n = 1, marked as a white circle with a black dot) or from additional untreated adult Tg25109 mice (n = 7, marked as white circles). Dots represent individual biological replicates and data are presented as mean ± 95% CI. Significance was calculated by two-tailed Student’s t-test; **P ≤ 0.01; ***P ≤ 0.001; ****P ≤ 0.0001. NS, not significant.
