Figure 4
Mouse bioassay of CWD prions from slice cultures. (A) Survival analysis of Tg12 mice intracranially inoculated with 5-µL lysates from homogenized CWD-inoculated brain slices during passage 1 (Pass 1) showing an incubation period of 208 days. Mice inoculated with NBH slices tested negative for PrPCWD at the end of the experiment. When Tg12 mice (Pass 2) were similarly injected with 5-µL of inoculum from Pass 1 mouse brains, the mean incubation period was reduced to 139.5 dpi. (B) RT-QuIC assay reaction traces (n = 4 replicates) showing efficient CWD prion transmission to the brains of mice in passage 1. (C) Immunohistochemistry of paraffin-embedded tissue sections showing neuropathology and CWD prion plaques in multiple brain regions of mice from Pass 2. No immunoreactivity is present in a representative section of the thalamus from a negative control Tg12 mouse. Plaques were more abundant in the granular layer of the cerebellum and hippocampus. A diffuse pattern was observed in the hypothalamus and medulla while a mixed pattern manifested in the midbrain and thalamus. Scale bars: 50 μm.
