Development of a candidate DNA/MVA HIV-1 subtype C vaccine for India

Development of a vaccine against human immunodeficiency virus type-1 (HIV-1) is the mainstay for controlling the AIDS pandemic. An ideal HIV vaccine should induce neutralizing antibodies, CD4+ helper T cells, and CD8+ cytotoxic T cells. While the induction of broadly neutralizing antibodies remains a highly challenging goal, there are a number of technologies capable of inducing potent cell-mediated responses in animal models, which are now starting to be tested in humans. Naked DNA immunization is one of them. The present study focuses on the stimulation cell-mediated and humoral immune responses by recombinant DNA-MVA vaccines, the areas where this technology might assist either alone or as a part of more complex vaccine formulations in the HIV vaccine development. Candidate recombinant DNA-MVA vaccine formulations expressing the human immunodeficiency virus-1 env and gagprotease genes from HIV-1 Indian subtype C were constructed and characterized. A high level of expression of the respective recombinant MVA (rMVA) constructs was demonstrated in BHK-21 cells followed by the robust humoral as well as cell mediated immune (CMI) responses in terms of magnitude and breadth. The response to a single inoculation of the rDNA vaccine was boosted efficiently by rMVA in BALB/c mice. This is the first reported candidate HIV-1 DNA/MVA vaccine employing the Indian subtype C sequences and constitutes a part of a vaccine scheduled to enter a preclinical non-human primate evaluation in India.