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


CONCLUSIONS
These newly identified CTL epitopes should be considered in the preclinical evaluation of T cell responses induced by Gag-based vaccines in mice.
Cellini
Silvia
S
Department of Biochemistry and Molecular Biology, Via L, Borsari 46, University of Ferrara, 44100, Ferrara, Italy. silvia.cellini@unife.it
Fortini
Cinzia
C
Gallerani
Eleonora
E
Destro
Federica
F
Cofano
Egidio Brocca
EB
Caputo
Antonella
A
Gavioli
Riccardo
R
D016915:AIDS Vaccines / Q000008:administration & dosage / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D003601:Cytotoxicity Tests, Immunologic; D018604:Epitope Mapping; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D015683:Gene Products, gag / Q000737:chemistry / Q000276:immunology*; D015696:Gene Products, tat / Q000008:administration & dosage / Q000276:immunology*; D015658:HIV Infections / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D015497:HIV-1 / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D016915:AIDS Vaccines; D018984:Epitopes, T-Lymphocyte; D015683:Gene Products, gag; D015696:Gene Products, tat; D010455:Peptides