Figure 4.

Analysis of total PrP and PrP^Sc levels in the brain of scrapie infected mice treated with polyclonal anti-LRP antibody W3 and preimmune serum at the terminal state. LRP/LR antibody W3 and preimmune serum was intraperitoneally injected into C57BL/6 mice for 12 weeks. One week after the first antibody/preimmune serum injection C57BL/6 mice were intraperitoneally inoculated with RML prions (10%). (A) Mice were sacrificed after showing two of the four characteristical TSE symptoms²⁵ over three days (terminal state) and total brain was analyzed for the PrP^Sc content (after Proteinase K digestion) by Western blot analysis using anti-PrP antibody SAF 83. PrP^Sc levels in total brain samples of three W3 and three preimmune serum treated mice are shown. β-actin was used as a loading control (detection by an anti-β-actin antibody). (B) Densitometric measurements of Western blots from six brain samples per group revealed a reduction of PrP^Sc levels by 17% in the W3 treated group compared to the preimmune serum treated group, for which the PrP^Sc level was set to 100% (p < 0.3). Quantification of PrP^Sc signals were normalized by β-actin levels. Quantification of the Western blot signals was carried out by densitometric measurements using the Image J software (mean + SD). (C) Total brain samples of terminal C57BL/6 scrapie infected mice were analysed for the total PrP content (in the absence of Proteinase K) by Western blot analysis using anti-PrP antibody SAF 32. Total PrP levels in total brain samples of three W3 and three preimmune serum treated mice are shown. β-actin was used as a loading control (detection by an anti-β-actin antibody). (D) Densitometric measurements of western blots from six brains per group revealed approx. equal levels in both groups (p < 0.2). Quantification of total PrP signals were normalized by β-actin levels. Quantification of the Western blot signals was carried out by densitometric measurements using the Image J software (mean + SD).