Figure 6. Schematic presentation of the RT-QuIC process with the potential points of action of doxycycline.

The black arrows mark the steps of RT-QuIC. Misfolded PrP^res (seed) comes in contact with cellular prion protein (substrate), followed by a conformational change of the substrate to a more seed-like conformation (transformation). Newly generated seed particles aggregate and the aggregates are detected by a fluorescent dye (detection not shown). Then the aggregates are shaken to break them into seed particles again (shaking). The amount of seed particles and thus the fluorescent intensity increases by repeating this cycle frequently. The blue arrows mark the potential interference of the PrP conversion process via doxycycline. The results of this study suggest that doxycycline may destabilise aggregated and PK-resistant PrP.