Identification of new HIV-1 Gag-specific cytotoxic T lymphocyte responses in BALB/c mice

Silvia Cellini¹ , Cinzia Fortini¹ , Eleonora Gallerani¹ , Federica Destro¹ , Egidio Brocca Cofano² , Antonella Caputo² and Riccardo Gavioli¹

¹Department of Biochemistry and Molecular Biology, Via L. Borsari 46, University of Ferrara, 44100, Ferrara, Italy

²Department of Histology, Microbiology and Medical Biotechnologies, Via A. Gabelli 63, University of Padova, 35121, Padova, Italy

author email corresponding author email

Virology Journal 2008, 5:81doi:10.1186/1743-422X-5-81


Published:	14 July 2008

Abstract

Background

As HIV-specific cytotoxic T cells play a key role during acute and chronic HIV-1 infection in humans, the ability of potential anti-HIV vaccines to elicit strong, broad T cell responses is likely to be crucial. The HIV-1 Gag antigen is widely considered a relevant antigen for the development of an anti-HIV vaccine since it is one of the most conserved viral proteins and is also known to induce T cell responses. In the majority of studies reporting Gag-specific cellular immune responses induced by Gag-based vaccines, only a small number of Gag T cell epitopes were tested in preclinical mouse models, thus giving an incomplete picture of the numerous possible cellular immune responses against this antigen. As is, this partial knowledge of epitope-specific T cell responses directed to Gag will unavoidably result in a limited preclinical evaluation of Gag-based vaccines.

Results

In this study we identified new Gag CD8+ T cell epitopes in BALB/c mice vaccinated with the HIV-1 Gag antigen alone or in combination with the HIV-1 Tat protein, which was recently shown to broaden T cell responses directed to Gag. Specifically, we found that CTL responses to Gag may be directed to nine different CTL epitopes, and four of these were mapped as minimal CTL epitopes.

Conclusion

These newly identified CTL epitopes should be considered in the preclinical evaluation of T cell responses induced by Gag-based vaccines in mice.