Research article

Successful adjuvant-free vaccination of BALB/c mice with mutated amyloid β peptides

Chuanhai Cao^1,2 , Xiaoyang Lin¹ , Monika M Wahi^1,3 , Eugene A Jackson¹ and Huntington Potter Jr^1,2

¹  Johnnie B. Byrd Alzheimer's Center and Research Institute, 4001 E. Fletcher Ave., Third Floor, Tampa, FL 33613, USA

²  University of South Florida College of Medicine, Dept. of Molecular Medicine, 12901 Bruce B. Downs Blvd. MDC 10, Tampa, FL 33612, USA

³  University of South Florida College of Public Health, Department of Epidemiology and Biostatistics, 13201 Bruce B. Downs Blvd. MDC 56, Tampa, FL 33612, USA

author email corresponding author email

BMC Neuroscience 2008, 9:25doi:10.1186/1471-2202-9-25

Published:	18 February 2008

Abstract

Background

A recent human clinical trial of an Alzheimer's disease (AD) vaccine using amyloid beta (Aβ) 1–42 plus QS-21 adjuvant produced some positive results, but was halted due to meningoencephalitis in some participants. The development of a vaccine with mutant Aβ peptides that avoids the use of an adjuvant may result in an effective and safer human vaccine.

Results

All peptides tested showed high antibody responses, were long-lasting, and demonstrated good memory response. Epitope mapping indicated that peptide mutation did not lead to epitope switching. Mutant peptides induced different inflammation responses as evidenced by cytokine profiles. Ig isotyping indicated that adjuvant-free vaccination with peptides drove an adequate Th2 response. All anti-sera from vaccinated mice cross-reacted with human Aβ in APP/PS1 transgenic mouse brain tissue.

Conclusion

Our study demonstrated that an adjuvant-free vaccine with different Aβ peptides can be an effective and safe vaccination approach against AD. This study represents the first report of adjuvant-free vaccines utilizing Aβ peptides carrying diverse mutations in the T-cell epitope. These largely positive results provide encouragement for the future of the development of human vaccinations for AD.