Expression of two loopsV3 from HIV-1 fused to cholera toxin A2B subunit using Lactococcus lactis as a vector to induce immunity in mucosa

Lactococcus lactis, a nonpathogenic bacterium has been used widely as a vector to deliver antigens to the mucosa; one of the principal threats to world health is AIDS and HIV infection, involving the passage of the virus across a mucosal surface. We used L. lactis to express V3 loop from HIV-1, A2B subunit of cholera toxin and their fusion with one or two loops V3 (V3A2B and V3V3A2B). Six-weeks-old Balb/c mice were orally immunized with the recombinant bacteria. Samples of serum, intestinal washes and PBMC lymphocytes were collected to detect IgA and IgG anti-V3, and IL-2 respectively. The recombinants that express the V3 alone or fused to the A2B induced anti-V3 IgA antibodies and anti-V3 IgG antibodies in serum and intestinal washes but recombinant V3V3A2B was the most efficient and the only one that induced the expression of IL-2 in PBMC when compared with the controls (p<0.05). We induced anti V3 IgG and IgA and IL-2 in mice immunized with L. lactis recombinants that express the antigen V3 fused to A2B subunit of CT; which suggests that this strategy could be used to induce immune response specific of HIV. Key words: HIV, vaccines, Lactococcus lactis, lactic acid bacteria, mucosal immunity.