Fig. 3: Cellular screening using deletion constructs of the tauRD reveals a differential relationship of APRs to tau aggregate strains.

a Intracellular seeding of cells expressing tauRD-YFP is reported by counting the number of cells with a punctuate morphology in a concentration-dependent manner upon treatment with rTau seeds. (Scale bar = 20 μm). b Dose-response curves after the treatment of cells expressing tauRD (WT) ΔPHF6*, ΔPHF6 or ΔPAM4 with various concentrations of rTau seeds or seeded with extracts isolated from three independent AD cases (n = 6, three independent samples with two technical repeats for each case). Individual points presented as mean values with ±SD. c Representative images of treated cells with selected seed concentrations (shown in arrow in b, Scale bar = 20 μm). d Inverted effects of the ΔPAM4 and ΔPHF6* on seeding efficiencies, shown as changes in EC₅₀ values, of recombinantly produced or AD extracted tau aggregates validates indicate that a bias towards specific tau polymorphs, in contrast to ΔPHF6 that is generally critical for tau aggregation. Bar plots represent mean values ± SD (n = 3 independent samples).