According to UNAIDS, most of the 10 countries with the highest HIV-1 prevalence are in southern Africa. Clearly, the development of any vaccine for AIDS would be trumpeted as a significant advance, however the development of an AIDS vaccine for populations in southern Africa and other developing countries is the highest priority. Most of the HIV-1 vaccines in clinical trials or development utilize plasmid DNA constructs for priming and/or boosting to drive Type 1 cytotoxic CD8+ T cells recognizing HIV-1 epitopes, plus/minus induction of neutralizing antibodies. This new innovations proposal focuses on enhancing an HIV-1C DNA (TD158) vaccine by incorporating Hsp70 coding regions into the plasmid DNA. Heat shock proteins have recently been shown to enhance uptake and processing of expressed proteins by dendritic cells. Thus, the goal of this proposal is to determine whether incorporating HspT0 coding regions to the TD158 plasmid DNA vaccine leads to enhanced dendritic cell activation, uptake and processing of TD158 antigens, giving rise to strong Type 1 CD8+ and Th1-type responses. In addition, we propose to produce TD158/Hsp70 plasmid DNA vaccine constructs that have the Ig-k leader sequence added to facilitate secretion of the TD158/Hsp70 vaccine to further enhance DC uptake and activation leading to DC1 maturation. We will also attempt to enhance TD158 plasmid DNA vaccine efficacy by boosting with TD158/HspT0 recombinant fusion proteins, formulated plus/minus a Th1-driving adjuvant. Our hypothesis is that one or more of these approaches will significantly enhance TD158 vaccine immunogenicity leading to greater CD8+ and CD4+ T cell activation compared to the current TD158 vaccine that is being developed.
The Specific Aims of this proposal are:
Aim 1. Determine if addition of Hsp70 coding regions to a TD158 plasmid DNA vaccine drives enhanced Type 1 T cell responses.
Aim 2. Will boosting with recombinant TD158 proteins or TD158/Hsp70 recombinant fusion proteins enhance immunogenicity of the TD158/Hsp70 plasmid DNA vaccine? Aim3. Will the Hsp70 enhanced HIV-1C vaccine drive strong Type1 T cell responses in Th2 biased recipients?
| Da'Dara, Akram A; Lautsch, Norman; Dudek, Timothy et al. (2006) Helminth infection suppresses T-cell immune response to HIV-DNA-based vaccine in mice. Vaccine 24:5211-9 |
