Avaliação do impacto da temperatura e da concentração de IPTG na expressão da proteína Rzv-TSP2 derivada de Schistosoma mansoni

Abstract

Schistosomiasis is endemic in tropical countries and affects 240 million people around the world, with the poorest countries and regions being the most affected because they have poor or no sanitation conditions. In Brazil, the parasite Schistosoma mansoni is the cause of the disease, whose records point 423,117 cases in the country between the years 2009 and 2019. A vaccine would be the best way to reduce the occurrence of schistosomiasis, however, due to its chronic nature of infections, it has not yet been possible to create a vaccine that produces consistent immunogenicity. Therefore, the aim of this work is to optimize the production of the vaccine candidate SmTSP-2 (protein located in the tegument of the parasite) fused to rizavidin, aiming its use in the construction of a Multiple Antigen Presenting System (MAPS). For this, two independent variables involved in the expression process were evaluated: temperature and concentration of the expression inducer IPTG. Using the Response Surface Methodology (RSM) and analyzing the results in Western Blot, it was possible to observe that temperature has a more significant role in protein expression compared to IPTG concentration: at 22oC the expression of Rzv-TSP2 occurred in soluble and insoluble fractions, in both IPTG concentrations tested (0.1 mM and 1 mM). At 37°C, the protein was only expressed in the insoluble fraction at 1 mM IPTG concentration.