Mucosal Immunization Schemes Based on Attenuated Modified Vaccinia Virus Ankara (MVA) Vectors Expressing HIV Antigens

CRISTIAN I. CAÑONES; ANA MARÍA RODRIGUEZ; EVA PÉREZ-JIMÉNEZ; JOSÉ L. NÁJERA; MARIANO ESTEBAN; HORACIO SALOMÓN; MAGDALENA GHERARDI

Córdoba, Córdoba

Congreso; 7º Congreso Latinoamericano de Inmunología; 2005

Asociación Latinoamericana de Inmunología

The major route of HIV transmission is through exposure of mucosal surfaces to the virus, moreover, during primary infection HIV rapidly targets and drastically depletes CD4+T cells in mucosal associated lymphoid tissues. Therefore, induction of mucosal immunity must be a goal of first priority in the design of vaccines against HIV. Employing different immunization schemes based on MVA recombinants we showed the ability of these vectors to induce immune responses at mucosal sites in Balb/c mice. We have demonstrated (J.Immunol.,2004,172:6209) that DNA prime-rMVA boost intranasal immunization schemes, in the presence of CT, induced strong cellular immune responses in spleen, genito-rectal draining lymph nodes (GRLN) and genital-tract, moreover vaginal antibodies to Env were also detected. Importantly, the specific CD8+T-cell populations induced secreted IFN-g and also different b-chemokines against the antigen. Another way to potentiate DNA vaccination is by its mucosal co-delivery with genetic vaccines encoding adjuvant molecules. Co-administration  of DNA encoding HIV-1 Env antigen, with DNA encoding IL-12, followed by a rMVA boost by intranasal route, induced a 4,5 fold increment in the specific CD8+T-cell response in spleen and a significant response in GRLN, compare to mice that not received  IL-12 at  priming. Studies resumed here indicated that it will merits to further explore mucosal immunization schemes based on rMVA expressing antigens of HIV in order to find the optimal immunization regimens capable of stimulating responses capable of control HIV infection locally.