Fig. 1
Selection and expression of β-amyloid peptide (Aβ) oligomer-specific mimotopes. a–d Aβ oligomer-specific antibodies purified from intravenous immunoglobulin G (IVIG-AβO) specifically recognized Aβ oligomers. The binding of IVIG-AβO to different Aβ forms was detected by enzyme-linked immunosorbent assay (ELISA) (a) and dot blot analysis (b), respectively. The brain homogenate of APP/PS1 mice (c) and 7PA2 cell lysates mixed with Aβ monomer (d) were separated on SDS-PAGE gels, and then Western blot analysis was performed with IVIG-AβO as primary antibodies. An irrelevant human monoclonal antibody and 4G8 were used as negative and positive controls, respectively. e Structural diagram of yeast-based vaccine. The mimotopes with c-Myc were linked with the C-terminal of AGA2 protein and displayed on the surface by interaction with AGA1. f C57BL/6 mice (female, 6 weeks of age, n = 3 for each group) were subcutaneously injected twice at a 2-week interval with eight candidate yeast-based vaccines in the absence of adjuvant. The antibody titers against mimotope peptides and Aβ42 oligomers in the mice immunized with different vaccines were detected by ELISA. One vaccine, EBY100-L2, was termed AOE1. g The AOE1 and Aβ1–15 were expressed and displayed on the surface the EBY100 yeast cells. The cells were probed with anti-Myc antibody and fluorescein isothiocyanate-labeled secondary antibody and then analyzed by flow cytometry. EBY100 yeast cells were used as a negative control. h Expression of AOE1 and Aβ1–15 was determined by confocal microscopy. The obvious fluorescent signals were detected on the surface of EBY100 yeast cells expressing L2 and Aβ1–15. Bar indicates 1 μm. OD450 Optical density at 450 nm