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

Dengue is the arbovirose with larger impact on public health worldwide. The disease is caused by the Dengue virus (DENV), that comprises four antigenically distinct serotypes of the virus in such a way that infection by one then does not imply protection against the heterologous serotypes. The clinical diagnosis of dengue is hard and therefore the laboratory diagnosis is an important tool to confirm of suspected cases. Serological tests on the ELISA platform are widely used for dengue infection diagnosis, because they are sensitive and affordable. However, their specificity is compromised particularly in regions where others arboviruses prevail. Therefore, the aim of this study was to develop specific serological diagnostic strategies for dengue in the ELISA platform using recombinant proteins developed from a fragment of NS1 protein (named &#916NS1 of the DENVs 1-4). The antigens were obtained after expression in prokaryotic system using Escherichia coli strains and purified by affinity chromatography. Importantly, the purified recombinant proteins were recognized by sera from animals infected by DENVs, suggesting that &#916NS1 antigens have their conformational epitopes preserved. Moreover, the &#916NS1 of DENVs 1-4 were used in combination as solid phase antigens and allowed the detection of DENV in the sera from infected animals, without cross reaction with antibodies after ZIKV infection. In addition, the &#916NS1 of the DENVs 1, 2 and 4 showed higher reactivity with the sera of the homologous DENV, thus indicating their potential as tools to specifically identify DENV sorotypes. The results are relevant and present novel immunobiologicals with preserved antigenicity, immunogenicity and can contribute to the development of new serological diagnostic strategies specific for dengue infection. (AU)