Effect of peptide derived from NS3 protein in the immune response of mice inoculated with inactivated Zika virus vaccine

Abstract

Zika Fever is a disease that affects many people in tropical and subtropical countries. The etiologic agent is Zika Virus (ZIKV), a single-stranded RNA flavivirus, transmitted mostly by Aedes mosquitoes, but sexual, congenital and blood transfusion transmission has also been reported. Due to the possible association of ZIKV to microcephaly and Guillain-Barré Syndrome, it is necessary to develop strategies for disease prevention. Among them, the best prophylactic measure is vaccination. The non-structural protein NS3 has been shown to stimulate cellular immunity response against others flaviviruses, and such activity has been used as a target against other flaviviruses infection. In this context, the aim of this project is to test the efficiency of NS3, in combination with inactivated vaccine, to increase the immunogenic capacity of this vaccine. NS3 sequence will be cloned in the pET-26b vector and expressed in E.coli BL21(DE3). Recombinant NS3 protein will be purified by nickel column affinity chromatography. ZIKV inactivation will be performed by the addition of formalin 0.05%. Several combinations of recombinant NS3 and inactivated viruses will be inoculated in 5 groups of mice C56BL/6 and A129 on days 0 , 7 and 14. In the 21th day, the hyper immune serum and splenocytes will be collected from C56BL/6 mice to evaluate: 1) the specific ZIKV antibody production by plaque reduction neutralization test (PRNT); 2) the cytokine profile Th1 or Th2 quantification by ELISA test and; 3) the existence of specific T lymphocytes against NS3 by ELISPOT. The A129 vaccinated mice will be challenged with wild ZIKV and measured their weight and survival for 10 days. The results will be analyzed by R studio software. This approach will give a possibility of assessing an effective and immunogenic vaccine to prevent ZIKV infection and thus, the development of the severe manifestations of this disease (AU)