Efficacy and Safety of the Immunization with DNA for Alzheimer's Disease in Animal Models: A Systematic Review from Literature

Abstract

Background: Alzheimer's disease (AD) is a neurodegenerative disease that does not have a proven cure; however, one of the most promising strategies for its treatment has been DNA vaccines. Objective: The present review is aimed to report the new developments of the efficacy and safety of DNA vaccines for AD in animal models. Method: The method PRISMA was used for this review. The article search was made in the electronic databases PubMed, LILACS, and Scopus using the descriptors "Alzheimer disease" and "Vaccine, DNA". Articles published between January 2001 and September 2017 in English, Portuguese, and Spanish were included. Results: Upon the consensus, the researchers identified 28 original articles. The studies showed satisfying results as for the decrease of amyloid plaques in mouse, rabbits, and monkeys brains using mostly the DNA A42 vaccine, AV-1955, and AdPEDI-(A1-6)11, mainly with a gene gun. In addition to a reduction in tau by the first DNA vaccine (AV-1980D) targeting this protein. The use of adjuvants and boosters also had positive results as they increased the destruction of the amyloid plaques and induced an anti-inflammatory response profile without side effects. Conclusion: The results of DNA vaccines targeting the amyloid-and the tau protein with or without adjuvants and boosters were promising in reducing amyloid plaques and tau protein without side effects in animals. Although there are many vaccines being tested in animals, few reach clinical trials. Thus, as a future perspective, we suggest that clinical studies should be conducted with vaccines that have been promising in animal models (e.g., DNA A42 vaccine, AV-1955, and AdPEDI-(A1-6)11).