Western blot of prion protein in brain, olfactory bulb, and nasal turbinate of mice following intranasal inoculation of prions in the absence and presence of a preexisting lesion to the olfactory epithelium.

<p>Immunodetection of the prion protein in tissues from C57Bl/6 mice (A, B) and HPrP7752KO transgenic mice (C, D) following intranasal inoculation of RML scrapie and HY TME, respectively. Mice were pretreated with vehicle (veh) and methimazole (mmi) 48 hours prior to prion inoculation. Clinically ill C57Bl/6 mice all had PrP^Sc deposition in brain (not shown), olfactory bulb (A), and nasal turbinate (B) following proteinase K (PK) digestion of tissue homogenates (A) and PrP^Sc enrichment methods that included a PK digestion step (B). In clinically ill HPrP7752KO mice, PrP^Sc was detected in brain (C), olfactory bulb (not shown), and in >75% of nasal turbinates (D) following PrP^Sc enrichment. Asterisk (C, D) indicates a mouse that did not develop clinical symptoms of prion disease and was devoid of PrP^Sc. In non-proteinase K (non-PK) treated samples, 20 μg protein from brain (C) and 40 μg protein from nasal turbinate (D) were analyzed while for PK treated samples, 100 μg protein from brain (C) and 1 mg protein from nasal turbinate (D) were used as starting material for PrP^Sc enrichment and analysis. RML scrapie-infected brain (Br) control is indicated.