Short Communication: Evaluation of immune responses from immunization of HIV-1 P24-Nef fusion peptide vaccine with Monophosphoryl Lipid A (MPL) in BALB/c mice

Several vaccines against HIV have been investigated but none has been approved as an effective HIV vaccine. An approach that could induce stronger immune response against the pathogen is utilizing a multi-epitopic vaccine. This strategy was used in the design of several vaccines and resulted in improved immune responses. In this study a multi-epitopic fusion peptide including parts of HIV-1 Nef and P24 as a vaccine candidate was injected into mice and immune humoral responses measured with total antibody and IgG sub-classes using ELISA. Also measurement of cellular immune responses through evaluation of spleen cells proliferation response using MTT and cytotoxicity by LDH were performed. Finally, the cytokine pattern of IFN-γ and IL-4 were also determined with ELISA. The results indicate that candidate vaccine stimulated mouse splenic lymphocyte proliferation response and also induced strong cytotoxicity responses. Analysis of humoral immune response has shown that the candidate vaccine has induced specific antibody production mainly of the IgG2a sub-class. Also cytokine pattern evaluation has shown that IFN-γ secretion was dominant. The use of immunogen and conserved epitopes from P24 and Nef induced strong humoral and cellular immune responses and this construct could be candidate for further studies in animal models.