Desenvolvimento e avaliação da imunogenicidade de uma vacina de DNA tetravalente combinada com adjuvantes genéticos contra os vírus dengue
A dengue é a mais importante arbovirose que afeta o homem e o aumento crescente de casos nas áreas endêmicas bem como a possível expansão da área de risco de infecção tem causado preocupação em todo o mundo. Atualmente, as medidas de controle da doença são baseadas no controle do vetor, mosquitos do...
|Nível de Acesso:||openAccess|
Universidade Federal de Viçosa
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|Citação:||PESSOA, Carine Ribeiro. Desenvolvimento e avaliação da imunogenicidade de uma vacina de DNA tetravalente combinada com adjuvantes genéticos contra os vírus dengue. 2016. 54f. Tese (Doutorado em Biologia Celular e Estrutural) - Universidade Federal de Viçosa, Viçosa. 2016.|
|Resumo inglês:||Dengue is the most important arboviral disease that affects humans and the increasing number of cases in endemic areas and the possible expansion of the infection risk area has caused concern around the world. Currently, the disease control measures are based on the vector control, the genus Aedes mosquitoes and these were not effective, since the infection numbers have increased about 30 times in the last 50 years. Dengue viruses have four serotypes DENV-1, DENV-2, DENV-3 and DENV-4 and infection with one serotype promote protective immunity against infection with the same serotype. In a second infection with a heterologous serotype, non-neutralizing antibodies produced in the first infection may increase the number of infected cells and thus exacerbate immune response. This phenomenon, known as ADE (antibody dependent enhancement) is related to the severe forms of the disease and for this reason, an effective vaccine against dengue should be tetravalent. This work aims to build a tetravalent DNA vaccine against dengue and additionally develop genetic adjuvants to enhance the immunogenicity of the vaccine. For this, DNA sequences corresponding to the domain III of the E protein of all four serotypes of dengue virus were cloned into the same expression vector. For the development of genetic adjuvants, genes of cytokines GM-CSF, IL-7 and IL-15 were separately cloned into the expression plasmid so that different associations of genetic adjuvants could be evaluated with the plasmid vaccine. The evaluation of the immunogenicity of the tetravalent vaccine DNA and its association with different adjuvants showed that there was a lymphoproliferative response against the proteins prM and E of DENV-3, and the splenocytes coming from the groups that received pVAX-EDIII1-4 and pVAX-IL15, pVAX-EDIII1-4 and pVAX- GMCSF and pVAX-EDIII1-4, pVAX-GMCSF and pVAX-IL7 showed higher response when re-stimulated in vitro. It can also be seen that B cells were increased in the groups vaccinated with pVAX-EDIII1-4 and pVAX-GMCSF and pVAX-EDIII1-4, pVAX-IL15 and pVAX-GMCSF. CD4+ T cell subpopulation was increased in the group immunized with pVAX-EDIII1-4 and pVAX-GMCSF while CD8 + T cells, in the group immunized with pVAX-EDIII1-4 and pVAX-IL7. We observed an increase in lymphocyte subpopulation of CD8 CD44+ CD62L- (effector memory-TEM) in the groups immunized with pVAX-EDIII1-4 and pVAX-IL7 and pVAX-EDIII1-4, pVAX-GMCSF and pVAX- IL7. Regarding the central memory (T CM - CD44+ CD62L+) CD4 and CD8 T cells the largest increase was in the group immunized with pVAX-EDIII1-4, pVAX-GMCSF and pVAX-IL15. The naïve CD4 and CD8 T cells are also increased in the group immunized with pVAX-EDIII1-4, pVAX-GMCSF and pVAX-IL15. In the neutralization test in vivo with DENV-2, there was 60% protection in animals that had neutralized the virus with the serum of animals immunized with pVAX-EDIII1-4 and pVAX-IL7; 40% protection in animals in which the virus neutralized by the serum of animals immunized with pVAX-EDIII1-4; pVAX-EDIII1-4, pVAX-GMCSF and pVAX-IL7; pVAX-EDIII1-4, pVAX-GMCSF and pVAX-IL15. In the same assay using DENV-1, we can observe that the group which virus was neutralized with serum from animals vaccinated with pVAX- EDIII1-4 and pVAX-IL7 survival was 80% and 60% in the groups receiving the neutralized virus with serum from animals vaccinated with pVAX-EDIII1-4, pVAX- EDIII1-4 and pVAX-GMCSF, pVAX-EDIII1-4, pVAX-GMCSF and pVAX-IL7 and pVAX-EDIII1-4, pVAX-GMCSF and pVAX -IL15. These results showed that DNA vaccine was able to induce an immune response and this response was aided by adjuvants tested.|