This project aims to develop and characterize a strategy for prophylactic vaccination against dengue virus serotype 2 (DENV2), based on NS3 protein helicase domain (NS3H) combined with three adjuvants and injected subcutaneously in mice. To do this, will be cloned and expressed the genes encoding NS3H and a non-toxic heat-labile toxin (LTG33D) from enterotoxigenic E. coli (ETEC) in recombinant strains of E. coli. Protein NS3H will be administered to BALB/c mice in combination with aluminum hydroxide, CpG-rich oligonucleotides (ODNs) or LTG33D. The cellular and humoral responses against NS3H will be monitored by testing the determination of circulating antibodies by ELISA assays and characterizing cellular responses mediated by T lymphocytes CD4+ and CD8+. The profiles of cytokine secretion and cell activation will be assessed by ELISPOT and ICS (intracellular cytokine staining). Further tests will be performed in a murine model challenge to determine the protective ability of vaccine formulations against the DENV2 infection. The safety of such formulations will be evaluated by analysing red and white blood cells counts, circulating cytokines, markers of liver function, levels of C-reactive protein and by pathological examinations. The development of a DENV2 vaccine represent an unprecedented contribution to science, which may later be associated with vaccines for other viral serotypes in order to generate a tetravalent vaccine formulation able to prevent dengue fever in humans. Furthermore, the data generated from this project will represent an important contribution to studies aimed at the development of vaccination strategies against dengue.
News published in Agência FAPESP Newsletter about the scholarship: