Clonagem e expressão de um antígeno quimérico contendo segmentos das glicoproteínas e1 e e2 do envelope do vírus da hepatite C

Abstract

Approximately 150 million people are infected chronically with hepatitis C virus (HCV). The development of vaccines has been hampered by the high genetic variability of the virus as well as by the lack of suitable animal models. In this study, we describe the construction of an artificial antigen containg segments of the HCV glicoproteins E1 and E2, expressed in bacterial system as a fusion protein (GST-E1E2), six and eight residues of histidine (6xhis and 8xHis). These segments we were selected by their ability to elicit neutralizing antibodies, described in scientific articles. Immunogenicity of GST-E1E2 was assessed by means of inoculation of mice and testing protein in the serum of these animals by ELISA against four synthetic peptides (I to IV) corresponding to segments E1E2 present in the sequence. Statistically significant reactivity was observed only against peptides I, II and IV compared between sera of immunized group and that GST-E1E2 immunized with GST. The serum was shown to have the highest reactivity by ELISA was used in indirect immunofluorescence (IFI) against CHO-K1 cells transfected with plasmid EFJFH c-NS2, which express the structural proteins of HCV, and also shown to be reactive, confirming that the observed ELISA was specific. These results indicate that some of the segments E1E2 present in the sequence and analyzed in this study were able to induce the production of antibodies against HCV.