Desenvolvimento de vacinas de DNA contra o vírus da dengue baseadas na proteína do envelope viral

摘要: Dengue is a disease caused by the dengue virus (DENV1-4). Despite several studies, no effective vaccine yet commercially available. The envelope protein (E) of DENV viral surface major component, associated with numerous biological activities. Thus, this main target for induction of a protective immune response based on neutralizing antibodies. In present study, we evaluated potential DNA vaccines expressing DENV2 E the induction protection. Two plasmids were constructed, pE1D2 and pE2D2, which contain sequences encoding ectodomain (domains I, II III) or only its domain III, respectively, cloned upstream sequence the human tissue plasminogen activator signal peptide (t-PA). Both mediated expression secretion recombinant proteins in vitro eukaryotic cells, detected anti-DENV2 antibodies immunofluorescence or metabolic labeling assay followed imunopreciptation. were elicited Balb/c mice, highest antibody titers detected animals immunized pE1D2. was also more protective challenge tests lethal dose DENV2, inducing 100% survival in immunized while 45% vaccinated plasmid pE2D2 died after infection. Furthermore, 10% 65% mice or pE2D2, respectively, showed morbidity after challenge. and pE2D2 tested combination chimeric YF17D-D2 virus, prime and booster system simultaneous immunizations. chimeric virus previously constructed replacing prM genes 17DD yellow fever vaccinal those from DENV2. combined with the chimera induced high levels animals vaccinated any different immunization schedules. Moreover, these animals rates against no clinical signs infection. synergistic effect also evident when we used which generated challenged animals. cellular was evaluated production IFN- CD8+ T cells ELISPOT assays, revealing the activation these alone in combination chimera. analysis phenotypic profile CD4+ low percentage CD62L+ lymphocytes in animals pE1D2, thus indicating that can influence processes cell activation. New DNA ectodomains DENV1, 3 4 protein (pE1D1, pE1D3 pE1D4) expression recombinant proteins confirmed vitro. These will be further animal models.