Immunological Evaluation of HIV-1 P24-Nef Harboring IFN-γas as an Adjuvant in BALB/c Mice

Despite the improvements in antiretroviral treatments, there is no authorized HIV vaccine; therefore, designing an effectual vaccine is essential. This study was aimed at the immunological evaluation of HIV-1 p24-Nef adjuvanted with IFN-γin BALB/c mice with the purpose of stimulating effective immune responses.

Forty-eight female mice were used for immunization by p24-Nef. The mice were divided into six cohorts with eight mice in each group. Immunizations were executed three times at three-week intervals and subcutaneously for 5μg per mouse. A couple weeks after the last injection, humoral and cellular immune pathways were appraised in blood serum and splenocytes respectively through applying ELISA.

The results showed that the applied regimen could elicit robust immune responses in comparison with the control. In addition, the level of total antibody production which was observed in the group containing adjuvanted antigen of interest had a significant difference with the control cohort (P<0.0001). Moreover, IgG2a was the uppermost isotype (Th1-biased response) in the immunized group that had p24-Nef antigen with IFN-γ adjuvant. In spite of antibody secretion, the cellular immune response was the predominant stimulated pathway. The potency of IFN-γ as an adjuvant for induction of a quantifiably extensive Th1 pathway was shown to be more significant given the outcomes of cytokine assay, IgGisotype, and CTL evaluation.

The results of the current study indicated that the p24-Nef antigen is able to stimulate the humoral and cellular immune responses in immunized mice, either on its own or when formulated with adjuvant. Thus, the high immune system stimulated by p24-Nef injection regimen went along with IFN-γ adjuvant, offering a potential option for an efficient vaccine against HIV-1.