Fig. 11

PHF and antibody binding differs depending on antibody and dosing method. Primary neurons were treated with 10 μg/ml human derived PHF material alone, PHF and 1 μg/ml 4E6 or 6B2 together (co-incubation), or 24 h PHF incubation followed by 4E6 or 6B2 for an additional 24 h. All coverslips were stained with Dako pan tau polyclonal antibody. a–d Neurons readily took up the PHF tau from the media and PHF positive puncta were detected in cell bodies and neuronal processes. e–h As shown above, PHF was taken up by the cultured neurons. 4E6 was added 24 h later and co-localized intracellularly with the exogenous PHF. i–l When added together, 4E6 and the PHF material formed large extracellular aggregates. m–p In the 4E6 → PHF group, PHF positive puncta were detected in the cells, but 4E6 was not. q–t When 6B2 was added 24 h after PHF, we observed intracellular co-localization. u–x Unlike 4E6, coincubation of 6B2 and PHF did not produce the large extracellular complexes. Y-BB When 6B2 was added before PHF, PHF but not 6B2 was seen in the cells