EFRH–Phage Immunization of Alzheimer's Disease Animal Model Improves Behavioral Performance in Morris Water Maze Trials

Abstract

We have developed an immunization procedure for the production of effective anti-beta-amyloid (anti-Abeta) antibodies, using filamentous phage displaying only 4 amino acids. The EFRH sequence, encompassing amino acids 3-6 of the 42 residues of Abeta peptide, was found previously to be the main regulatory site for amyloid modulation and the epitope of anti-aggregating antibodies. Engineered filamentous phage enable the display of various numbers of EFRH copies on the phage and serve as potent carriers of antigens. In the present study we have found that phage displaying high EFRH copy number are effective in eliciting humoral response against the EFRH sequence, which in turn relieves the amyloid burden in the brains of amyloid precursor protein Tg mice and improves their ability to perform cognitive tasks.

Vaccination with Aβ-Displaying Virus-Like Particles Reduces Soluble and Insoluble Cerebral Aβ and Lowers Plaque Burden in APP Transgenic Mice

“…However, adjuvants that potently stimulate innate immune responses may have unwanted effects in humans-even if considered safe in mouse models (10 -12, 14, 53). Alternatively, A␤ display via Escherichia coli filamentous or Q␤ phage (47,54,55) and A␤ presented on the surface of nonenveloped papilloma VLPs has been used (52, 55) as immunogens. Zamora et al (51) fused A␤1-9 to the major capsid protein L1 of Bovine papilloma virus.…”

Molecular basis for passive immunotherapy of Alzheimer's disease

“…We observed clear peptide electron density in a PFA1-AKFRHD cocrystal structure. Binding of the AKFRHD (''E3K'') peptide to PFA1 is nearly identical (C␣ RMSD is 0.23 Å) to that of A␤ (1)(2)(3)(4)(5)(6)(7)(8), except that it is the tail of the substituted lysine residue rather than the glutamate making a hydrogen bond with L Ser-32 (SI Fig. 6).…”

“…Passive immunization with humanized anti-A␤ monoclonal antibodies (mAbs) (3) is in phase II trials as an Alzheimer's therapy (www.elan.com/researchdevelopment/ Alzheimers/). Because the EFRHD motif (A␤ residues 3-7) appears to be an immunodominant segment of A␤ (4,5) and immunization to the EFRH sequence rescues cognitive function in mouse models of AD (6,7), it is important to understand the structural basis of antibody recognition of this sequence.…”

Immunization Therapy for Alzheimer Disease: A Comprehensive Review of Active Immunization Strategies

“…APP tg mice inoculated and repeatedly boosted intra-peritoneally or nasally with 10 10-11 of the recombinant phage produced antibodies to Aβ , and showed significant reduction of SPs and improvement of the Morris water maze test (Frenkel et al 2000;Lavie et al 2004). The recombinant phage with high copy numbers of Aβ was much more efficient.…”

“…Nasal with Protollin * (Frenkel et al 2005) BSAT, bovine serum albumin T cell epitope; CFA, complete Freund's adjuvant; I.P., intraperitoneal injection; I.V., intravenous injection; MLV, murine leukemia virus; PADRE, pan-HLA-DR binding peptide; PDGFR, platelet-derived growth factor receptor; Protollin, non-covalent formulation of outer membrane proteins (proteosomes) of Neisseria meningitides and LPS from Shigella flexneri; RGD, cell attachment motif; S.C., subcutaneous injection; T1, T cell epitope of HIV IIIB gp120. (Frenkel et al 2000;Lavie et al 2004) CT, cholera toxin; EFRH, aminoacid sequence of Aβ 3-6. Table 4.…”