RESUMO
BACKGROUND: Application of adjuvants with microbial origins is a recently highlighted approach in the vaccinology trials. Archaeosomes are among these microbial compounds with both adjuvant and liposomal activities and features. METHODS: In the present study, recombinant HBsAg encapsulated into Methanobrevibacter smithii (M. smithii) archaeosomes. Balb/c mice immunized with this compound and humoral and cytokine secretion pattern of immunized models analyzed. RESULTS: Frequency of IFN-γ secreting cells in the HBsAg-containing archaeosomes group was significantly higher than HBsAg and HBsAg(+)C/IFA groups (p≤0.05). IgG2a titer in the sera of HBsAg-containing archaeosomes group was also significantly higher than this subclass titer in the other groups (p≤ 0.05). CONCLUSION: Analysis of induced responses revealed the immunopotentiating characteristics of M. smithii archaeosomes in the induction of T-helper 1 responses according to the dominance of IgG2a subtype and IFN-γ secreting splenocytes of immunized mice.
RESUMO
Despite the worldwide efforts made in the field of HIV vaccine development, an efficient AIDS vaccine strategy is still vague. Virus-like particles (VLPs) are one of the introduced aspects for HIV vaccine development since the non-replicative nature of HIV VLPs, resulting from the lack of viral genomic RNA, makes them suitable for broad applications. We have previously designed and introduced non-infectious VLPs (mzNL4-3) by introduction of a deletion mutation in the reverse transcriptase and integrase coding regions of HV-1. There are evidences suggesting that an effective cellular immune response against HIV-1 is able to control and suppress viremia during primary and chronic HIV infections. In the present study we have evaluated the potency of mzNL4-3 VLPs mixed with Neisseria meningitidis serogroup B outer-membrane vesicle (OMV), which is among the microbial components with proved adjuvant properties, to induce humoral and cellular responses against HIV-1. Analysis of anti-HIV-1 responses elicited in immunized BALB/c mice following different immunization regimens indicated OMV+VLP as an immunopotent combination which significantly induced anti-HIV-1 IgG with IgG2a dominancy. Results of cytokine and ELISpot assays also showed the capability of VLP+OMV immunogen for effective induction of IFN-gamma; and IL4 secreting cells and further suggested the promotion of Th1-oriented response that was evidenced with the increased IFN-γ/IL4 secretion ratio. According to our study, HIV-1 VLPs combined with N. meningitidis B OMVs seem to be a promising approach in vaccine development against HIV-1.
