Development of new serological diagnostic strategies for typing prior Dengue virus infection

• Grant number: 17/09661-0
• Support type: Scholarships in Brazil - Master
• Effective date (Start): September 01, 2017
• Effective date (End): March 31, 2019
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal researcher: Luis Carlos de Souza Ferreira
• Grantee: Samuel Santos Pereira
• Home Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The Dengue virus (DENV) belongs to the family Flaviviridae, genus flavivirus, being the agent that causes dengue, a disease with a great impact on the world public health. Four serotypes of DENV (1, 2, 3 and 4) capable of infecting humans are known, and a large number of clinical manifestations are similar among serotypes, which makes it difficult to distinguish between them based on only clinical exams. In addition, the co-circulation with the Zika and Yellow Fever viruses, which have evolutionary kinship and antigenic similarity with DENV, constitutes a difficulty in establishing specific serodiagnostic assays for the Dengue virus. The serological differentiation between the four serotypes of DENV still remains challenging, being essential in determining the epidemiology of this infection and in the management of infected patients. To achieve this goal, fragments of the recombinant NS1 proteins (referring to amino acids 250-352 of each DENV virus serotype) will be expressed in prokaryotic systems and further purified by affinity chromatography. The antigens produced will be evaluated for the potential for application in serological tests on the ELISA platform, mainly identifying specificity and preservation of antigenicity. The structural differences between the NS1250-352 variants of Dengue viruses will be evaluated in a circular dichroism assay. Finally, the purified antigens will be used in standardization of ELISA assays, in order to establish strategies able to serotype the previous infection by the different serotypes of DENV. (AU)