Email updates

Keep up to date with the latest news and content from Retrovirology and BioMed Central.

This article is part of the supplement: AIDS Vaccine 2012

Open Access Oral presentation

Antibodies to the envelope protein protect macaques from SIVmac251 acquisition in an immunization regimen that mimics the RV-144 Thai trial

G Franchini1*, P Pegu1, S Gordon1, B Keele2, M Doster1, Y Guan3, G Ferrari4, R Pal5, MG Ferrari6, S Whitney7, L Hudacik7, E Billings8, M Rao8, D Montefiori9, D Venzon1, C Fenizia1, J Lifson2, D Stablein2, J Tartaglia10, N Michael11 and J Kim12

  • * Corresponding author: G Franchini

Author Affiliations

1 NCI/NIH, Bethesda, MD, USA

2 NCI-Frederick, Frederick, MD, USA

3 Institute of Human Virology Maryland University School of Medicine, Baltimore, MD, USA

4 Duke University, Durham, NC, USA

5 Advanced Bioscience Laboratories, Rockville, MD, USA

6 ABL, Rockville, MD, USA

7 Advanced Biosciences Laboratories, Rockville, MD, USA

8 Army Institute of Research, Silver Spring, MD, USA

9 Duke University Medical Center, Durham, NC, USA

10 Sanofi Pasteur Inc, Swifter, PA, USA

11 Walter Reed Army Intitute of Research, Silver Spring, MD, USA

12 Walter Reed Army Institute of Research, Sliver Spring, MD, USA

For all author emails, please log on.

Retrovirology 2012, 9(Suppl 2):O2  doi:10.1186/1742-4690-9-S2-O2

The electronic version of this article is the complete one and can be found online at: http://www.retrovirology.com/content/9/S2/O2


Published:13 September 2012

© 2012 Franchini et al; licensee BioMed Central Ltd.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Background

The canarypox vector ALVAC-HIV, together with the HIV gp120 envelope, has protected 31.2% of Thai heterosexual individuals from HIV acquisition in the RV144 HIV vaccine trial. This outcome was unexpected, given the limited ability of the ALVAC-HIV vaccine component to induce CD8+T-cell responses, and of the HIVgp120 envelope to elicit broad neutralizing antibodies.

Methods

We vaccinated macaques with an immunization regimen that mimics the RV144 trial and exposed them to a mucosal dose of SIVmac251 that transmits few virus variants, similar to HIV transmission to humans.

Results

Vaccination induced anti-envelope antibodies, modest CD4+ and CD8+ T-cell responses. One third of the vaccinated macaques were protected from SIVmac251 acquisition, whereas the remaining infected vaccinees progressed to disease. Vaccine induced SIV mac251 specific T-and B-cell responses were not different in protected or infected animals. The sera of the animals protected had higher avidity antibodies to the gp120 envelope protein, recognized the variable envelope region V2, and reduced SIVmac251 infectivity in cells that express high level of α4β7, suggesting a functional role to antibodies to V2.

Conclusion

The SIV mac251 infection macaque faithfully reproduces results in humans, and is instrumental in the development of more efficacious vaccines for HIV.