title: Immunization with Small Amyloid-β-derived Cyclopeptide Conjugates Diminishes Amyloid-β-Induced Neurodegeneration in Mice.
abstract: Soluble oligomeric (misfolded) species of amyloid-β (Aβ) are the main mediators of toxicity in Alzheimer's disease (AD). These oligomers subsequently form aggregates of insoluble fibrils that precipitate as extracellular and perivascular plaques in the brain. Active immunization against Aβ is a promising disease modifying strategy. However, eliciting an immune response against Aβ in general may interfere with its biological function and was shown to cause unwanted side-effects. Therefore, we have developed a novel experimental vaccine based on conformational neo-epitopes that are exposed in the misfolded oligomeric Aβ, inducing a specific antibody response.
  
  
  
  Here we investigate the protective effects of the experimental vaccine against oligomeric Aβ1-42-induced neuronal fiber loss in vivo.
  
  
  
  C57BL/6 mice were immunized or mock-immunized. Antibody responses were measured by enzyme-linked immunosorbent assay. Next, mice received a stereotactic injection of oligomeric Aβ1-42 into the nucleus basalis of Meynert (NBM) on one side of the brain (lesion side), and scrambled Aβ1-42 peptide in the contralateral NBM (control side). The densities of choline acetyltransferase-stained cholinergic fibers origination from the NBM were measured in the parietal neocortex postmortem. The percentage of fiber loss in the lesion side was determined relative to the control side of the brain.
  
  
  
  Immunized responders (79%) showed 23% less cholinergic fiber loss (p = 0.01) relative to mock-immunized mice. Moreover, fiber loss in immunized responders correlated negatively with the measured antibody responses (R2 = 0.29, p = 0.02).
  
  
  
  These results may provide a lead towards a (prophylactic) vaccine to prevent or at least attenuate (early onset) AD symptoms.
authors.affiliation: University of Groningen, Groningen Institute of Evolutionary Life Sciences, Groningen, The Netherlands.
authors.forename: Cornelis K
authors.initials: CK
authors.lastname: Mulder
authors.affiliation: University of Groningen, Groningen Institute of Evolutionary Life Sciences, Groningen, The Netherlands.
authors.forename: Yun
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Institute for Translational Vaccinology (Intravacc), Bilthoven, The Netherlands.
authors.forename: Humphrey F
authors.initials: HF
authors.lastname: Brugghe
authors.affiliation: Institute for Translational Vaccinology (Intravacc), Bilthoven, The Netherlands.
authors.forename: Hans A M
authors.initials: HA
authors.lastname: Timmermans
authors.affiliation: Institute for Translational Vaccinology (Intravacc), Bilthoven, The Netherlands.
authors.forename: Wichard
authors.initials: W
authors.lastname: Tilstra
authors.affiliation: Institute for Translational Vaccinology (Intravacc), Bilthoven, The Netherlands.
authors.forename: Janny
authors.initials: J
authors.lastname: Westdijk
authors.affiliation: Institute for Translational Vaccinology (Intravacc), Bilthoven, The Netherlands.
authors.forename: Elly
authors.initials: E
authors.lastname: van Riet
authors.affiliation: National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Harry
authors.initials: H
authors.lastname: van Steeg
authors.affiliation: Institute for Translational Vaccinology (Intravacc), Bilthoven, The Netherlands.
authors.forename: Peter
authors.initials: P
authors.lastname: Hoogerhout
authors.affiliation: University of Groningen, Groningen Institute of Evolutionary Life Sciences, Groningen, The Netherlands.
authors.forename: Ulrich L M
authors.initials: UL
authors.lastname: Eisel
mesh_terms: D016229:Amyloid beta-Peptides / Q000737:chemistry* / Q000276:immunology / Q000633:toxicity; D000818:Animals; D020532:Basal Nucleus of Meynert / Q000378:metabolism / Q000473:pathology; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D007114:Immunization / Q000379:methods*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D019636:Neurodegenerative Diseases / Q000139:chemically induced / Q000276:immunology / Q000628:therapy; D010446:Peptide Fragments / Q000737:chemistry* / Q000276:immunology / Q000633:toxicity; D010456:Peptides, Cyclic / Q000737:chemistry* / Q000276:immunology*
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; D010456:Peptides, Cyclic; C075222:amyloid beta-protein (1-42); D002795:Choline O-Acetyltransferase
keywords: Alzheimer’s disease; amyloid-β protein (1–42); cholinergic fibers; cyclopeptides; immunization; mice; nucleus basalis of Meynert; stereotactic injection