Background: The diagnosis of HIV infection is important among different groups.
Moreover, combination antiretroviral therapy is used to treat HIV-1, but it cannot eradicate the infection.
Thus, the development of therapeutic vaccines, along with antiretroviral therapy, is recommended.
This study evaluates the values of four HIV proteins as antigen candidates in therapeutic
vaccine design as well as a possible diagnostic marker for HIV infection in humans.
Methods: In this study, the HIV-1 Tat and Rev regulatory proteins and structural Gp120 and p24
proteins were generated in E. coli expression system. Their immunogenicity was evaluated in BALB/
c mice using homologous and heterologous prime/boost strategies. Moreover, the detection of anti-
HIV IgG antibodies against these recombinant proteins was assessed in untreated (Naïve/ HIV-infected),
treated, and drug-resistant patients compared to the healthy (control) group as a possible diagnostic
marker for HIV infection.
Results: In humans, our results showed that among HIV-1 proteins, anti-Gp120 antibody was not
detected in treated individuals compared to the healthy (control) group. The levels of anti-Gp120
antibody were significantly different between the treated group and Naïve as well as drug-resistant
subjects. Moreover, the level of anti-p24 antibody was significantly lower in the treated group than
the Naive group. In mice, the results of immunization indicated that the Rev antigen could significantly
induce IgG2a, IgG2b, and IFN-γ secretion aimed at Th1 response as well as Granzyme B
generation as CTL activity in comparison with other antigens. Furthermore, the heterologous DNA
prime/ protein boost regimen was more potent than the homologous regimen for stimulation of cellular
Conclusion: Briefly, the levels of both anti-Gp120 and anti-p24 antibodies can be considered for
the diagnosis of the HIV-infected individuals in different groups compared to the healthy group.
Moreover, among four recombinant proteins, Rev elicited Th1 cellular immunity and CTL activity
in mice as an antigen candidate in therapeutic vaccine development.