Fig. 9

4E6, but not 6B2, prevented the increase in the phosphorylated tau/NeuN ratio caused by exposure to 10 μg/ml PHF. a–c Samples probed with a polyclonal antibody recognizing tau phosphorylated at Ser199 from cells exposed to PHF alone or PHF in combination with a 4E6, b 6B2 or c control IgG1. d PHF alone samples had significantly reduced phospho-tau levels relative to untreated cells (34 % reduction, p < 0.05). For 4E6, both the PHF + Ab and PHF → Ab treatment groups had significantly higher phospho-tau levels than the PHF alone group (p < 0.001 and 0.05 respectively). e In samples treated with a combination of PHF and 6B2, none of the treatment groups were significantly different from PHF alone. f As with 6B2, uncorrected IgG1 samples showed no significant difference relative to PHF alone. g Correcting for NeuN levels to take PHF toxicity into account, PHF alone samples had higher ratio of P-Ser199/NeuN, compared to untreated controls (a 4.1 fold increase, p < 0.0001). Phospho- tau levels in the 4E6 PHF + Ab and PHF → Ab groups were significantly lower than the PHF alone samples (91 and 78 % of untreated controls, p < 0.0001). h When corrected for NeuN levels, 6B2 treated cells were not significantly different from PHF alone samples. i When NeuN levels were considered, IgG1 samples were also not significantly different from PHF alone