Amyloid-β targeting immunisation in aged non-human primate (Microcebus murinus).

Area of Science:

• Neuroscience
• Immunology
• Gerontology

Background:

• Non-human primates are crucial for translational research due to their close relation to humans.
• Aging primates exhibit Alzheimer's disease (AD)-like pathology, making them valuable models for therapeutic evaluation.
• Current immunotherapies for AD require further investigation into their safety and efficacy.

Purpose of the Study:

• To assess the safety and efficacy of an active immunization using a novel amyloid-beta (Aβ) derivative (K6Aβ1-30-NH2) in aged non-human primates.
• To investigate the potential of this Aβ-targeting immunotherapy to mitigate AD-like pathology and cognitive decline.

Main Methods:

• Thirty-two aged mouse lemurs (4-10 years old) were vaccinated with K6Aβ1-30-NH2 in alum adjuvant or adjuvant alone.
• Subcutaneous injections were administered up to four times.
• Brain pathology and general health were monitored post-vaccination.

Main Results:

• Vaccination led to a significant reduction in intraneuronal amyloid-beta (Aβ) and decreased microgliosis in the brain.
• No microhemorrhages were observed, indicating a favorable safety profile.
• Subtle cognitive improvements were noted in vaccinated primates, potentially linked to Aβ clearance.

Conclusions:

• The Aβ derivative vaccine demonstrated safety as a prophylactic measure in aged non-human primates.
• The vaccine effectively reduced key Alzheimer's disease pathologies and showed potential for cognitive benefits.
• This study supports further development of Aβ-targeting immunotherapies for Alzheimer's disease.