Cationic nanoglycolipidic particles as vector and adjuvant for the study of the immunogenicity of SIV Nef protein.

The objective of this study was to test the immunogenicity of SIV Nef protein formulated in cationic nanoglycolipidic particles of 100nm of diameter. In parallel, the adjuvant effect of these nanoglycolipidic particles was compared in similar experiments using GST-Nef in association with the commonly strongest used complete Freund's adjuvant (CFA) or incomplete Freund's adjuvant in association with MDP or MDP alone. Our results showed that these particles do not alter the integrity of our immunogen GST-Nef, which remains stable for more than three months at 4°C. We demonstrated that in the presence of nanoglycolipidic particles antibodies against Nef were produced since the first injection and remained stable after the third injection with high titers for long lasting periods as observed with CFA and IFA/MDP adjuvant. The analysis of immunoglobulin isotype profiles of antibodies generated by the different protocols of immunization showed the preponderance of IgG1 isotypes suggesting the predominance of Th2-type immune response.