Binding and function of nAbs on Aβ_1–42.

(A) Interaction between nAbs and Aβ1–42 in Dot Blot. Aβ1–42 oligomers were dotted in a decreasing concentration pattern, and the membrane was further incubated in nAbs-solution. To exclude unspecific binding, the membrane was also incubated with secondary antibody only (control; anti-human 1:500,000). One out of three independent experiments is shown. (B) Measurement of Aβ1–42 binding to nAbs by ELISA. The surface of a 96-well plate was coated with Aβ1–42 and incubated with different concentrations of nAbs/ IVIg. The data were normalized to the highest nAbs-Aβ concentration. (C) SPR sensorgram of Aβ1–42 interaction. Aβ1–42 was used as ligand whereas nAbs were used as analytes. The graph shows the different binding affinities between nAbs/ IVIg and the Aβ1–42 peptide. Interaction was measured between about 1000 RUs Aβ1–42 and 0.5 μM nAbs/ IVIg. Interactions are presented after a Langmuir fitting. (D) ThT-assay of Aβ1–42 following treatment with different nAbs for quantification of fibril formation. Aβ was incubated with or without nAbs/ IVIg. (E) FACS analysis of Aβ1–42 uptake by microglial BV-2 cells in the presence of different nAbs. Aβ1–42 was oligomerized first and then preincubated with nAbs/ IVIg before treatment of BV-2 cells. For B, D, E mean values ± SD of three independent experiments are shown. For every assay, IVIG was used as a reference control.