Induction of Broad-Based Immune Response Against HIV-1 Subtype C gag DNA Vaccine in Mice

Recent advances on HIV DNA vaccines development: Stepwise improvements to clinical trials

According to WHO (World Health Organization) reports, more than 770,000 people died from HIV and almost 1.7 million people becoming newly infected in the worldwide in 2018. Therefore, many attempts should be done to produce a forceful vaccine to control the AIDS. DNA-based vaccines have been investigated for HIV vaccination by researches during the recent 20 years. The DNA vaccines are novel approach for induction of both type of immune responses (cellular and humoral) in the host cells and have many advantages including high stability, fast and easy of fabrication and absence of severe side effects when compared with other vaccination methods. Recent studies have been focused on vaccine design, immune responses and on the use of adjuvants as a promising strategy for increased level of responses, delivery approaches by viral and non-viral methods and vector design for different antigens of HIV virus. In this review, we outlined the aforementioned advances on HIV DNA vaccines. Then we described the future trends in clinical trials as a strong strategy even in healthy volunteers and the potential developments in control and prevention of HIV.

Augmentation of HIV-1 subtype C vaccine constructs induced immune response in mice by CpG motif 1826-ODN

The greatest biomedical challenge of this century is to develop a preventive vaccine against Human Immunodeficiency Virus (HIV-1). For an HIV vaccine to be effective, it appears logical to develop new strategies that enhance the level of the immune response as well as steer it towards the desirable cellular type. In view of this, there is a need for rational inclusion of biological adjuvants into the HIV-1 vaccination strategies that could potentiate the immune responses both qualitatively and quantitatively. The adjuvant may include the immunostimulatory oligonucleotides containing CpG motifs, whose immunomodulatory characters are well established and represent the basis for an effective vaccine adjuvant. In our study, we investigated the use of an immunostimulatory oligonucleotide (or CpG motif), 1826-ODN to augment the immune response elicited by plasmid DNA vaccine constructs containing Indian subtype C HIV-1 envelope gp120 and gag-protease genes in Balb/c mouse model system. A dose of 2-microg CpG motifs/mouse was found to be optimum when co-administered with the DNA vaccine constructs with the peak level of humoral and cell mediated immune responses at 6 weeks post immunization. Murine IFN-gamma ELISpot assay demonstrated that the use of 1826-ODN led to a broad based and long term recognition of the subtype C envelope and gag peptides. The use of CpG motifs has been effective in augmenting the immune responses generated by the DNA constructs. Taken together, these results are an important advancement towards the design of future preclinical and clinical trials of these vaccine constructs.