Immunocytochemical Characterization of Alzheimer’s Disease Hallmarks in APP/PS1 Transgenic Mice Treated with a New Anti-Amyloid-β Vaccine

Abstract

Introduction

APP/PS1 double-transgenic mouse models of Alzheimer’s disease (AD), which overexpress mutated forms of the gene for the human amyloid precursor protein (APP) and presenilin 1 (PS1), have provided robust neuropathological hallmarks of an AD-like pattern at early ages. This study aimed to characterize immunocytochemical patterns of the AD mouse brain, which is treated with the EB101 vaccine, as a model for human AD.

Material and methods

In this novel vaccine, a new approach has been taken to circumvent past failures with Aβ vaccines by judiciously selecting an adjuvant consisting of a physiological matrix embedded in liposomes, composed of naturally occurring phospholipids (phosphatidylcholine, phosphatidylglycerol, and cholesterol).

Results

Our findings showed that the administration of amyloid-β1–42 (Aβ) and sphingosine-1-phosphate emulsified in liposome complex (EB101) to APP/PS1 mice before the onset of Aβ brain deposition (at 7 weeks of age) and/or at an older age (35 weeks of age) can be effective in both halting the progression and clearing the AD-like neuropathological hallmarks. In addition, passive immunization with EB101 did not activate inflammatory responses from the immune system and astrocytes. Consistent with a decreased inflammatory background, the basal immunological interaction between the T cells and the affected areas (hippocampus) in the brain of treated mice was notably reduced.

Conclusion

These results provide strong evidence that immunization with the EB101 vaccine prevents and attenuates AD neuropathology in this type of double-transgenic mice.