Expressão transitória da glicoproteína S1 recombinante do vírus da bronquite infecciosa em células de mamíferos

Abstract

The infection with infectious bronchitis virus (IBV) has been the cause of significant economic losses in the poultry world. The IBV has several genotypes and serotypes that differ widely in their pathogenicity. Some strains have a worldwide distribution. Among the proteins that make up the IBV, the S glycoprotein (subdivided into S1 and S2) stands out for being highly glycosylated. The S1 subunit is the major inducer of neutralizing antibodies and protective immune response. It’s responsible for adsorption of the virus to receptors on host cells, to determine the serotype of IBV, and for being a major determinant of cell tropism. Due to the complexity of the processes that occurs during the synthesis of the glycoprotein S1, the expression system in mammalian cell has characteristics such as post-translational modifications, like glycosylation, which makes it more attractive for the synthesis of this protein. The present study aimed to clone and express transiently the synthetic gene S1 glycoprotein of IBV produced from consensus sequences of brazilian and international samples. It had been used HEK 293 (Human embrionary kidney) and HeLa (Human cervical cancer). The gene was cloned into mammalian expression vector and transfected in cell culture. After 96 hours the supernatant cell and the lysed cell were collected. Expression and purification of recombinant S1 glycoprotein (rS1-IBV) were verified using the technique of SDS-PAGE and subsequently characterized by Western blotting using hyperimmune serum anti-IBV. It had been detected rS1-IBV from the cell supernatant. There was no detection of the recombinant protein from cell lysed of both cell. The study proved that it is possible to express recombinant S1 glycoprotein in mammalian cells.