Enhancement of HIV-1 DNA vaccine immunogenicity with CpG adjuvant

Objective To explore the capacity of CpG as adjuvant in improving HIV-1 DNA vaccine immunogenicity in animal models.Methods Balb/c mice were administrated thrice intramuscularly with CpG oligonucleotide adjuvanted HIV-1 DNA vaccine,pDRVI1.0-gp1455m.Cellular immune response was evaluated by detecting IFN-γ and IL-2 with ELISPOT.Humoral immune response was evaluated with Env-specific ELISA and avidity ELISA.The activation efficacy of bone marrow-derived dendritic cells(BMDC) was measured by the expression of surface molecules and the secretion of several cytokines after being exposed to CpG adjuvant in vitro.Results The results demonstrated that CpG increased HIV specific cellular response and reduced the dosage of DNA vaccine.In vitro,CpG adjuvant activated BMDC and up-regulated the expression of CD40,CD80,CD86 and MHC-I.CpG adjuvanted HIV DNA vaccine also promoted Th1-type immunological response and induced inflammation.Conclusion CpG is a promising adjuvant for the development of HIV DNA vaccine.