Cloning Of S1 Gene Of Avian Infectious Bronchitis Virus And Porcine IgGFc Gene And Their Fusion Expression In Hela Cells

Avian infectious bronchitis (IB) that mostly brings a severe respiratory disease in chicken at certain age is one of the severe diseases caused by Avian Infectious Bronchitis Virus(IBV). IB caused a great economic loss in almost all the countries where chicken was raised. The current serotypes of IBV are over 29 serotypes. New strains are continuously identified, which has brought many problems on diagnosis and control of IB. Spike(S) protein locates in the surface of virion particles and usually is cleaved into two parts designated S1 and S2, both of which are glycoproteins linking together by uncovalent bond. S1 glycoprotein participates in receptor-binding and determines the tissue tropism. S1 is also responsible for the viral hemagglutination capacity and serological taxonomy. Furthermore, S1 is the the major antigen which can induce the neutralization antibody and hemagglutination inhibition antibody, specific CTL immune response.IgG is the major antibody in humoral immunity, mostly existing in monomers in natural infection or artificial immunization. IgG is hydrolyzed into two fragments with the enzyme papain, Fragment antigen binding (Fab) and fragment crystalizable (Fc). The fragment Fc comprises of the constant region of IgG heavy chain, and determines the species specificity of each immune globulin.The strong binding capacity to SPG(streptococcus protein G) and SPA (Staphylococcal protein A) for the fragment Fc impels it to be a label in protein isolation or identification. In addition, IgG Fc fragment has a long half-life time in vivo and can be recognized by antigen presenting cell (APC). This implies the potential of IgG Fc to be a new molecular adjuvant.This study was aimed to clone S1 gene of avian infectious bronchitis virus and porcine IgG Fc gene, and express them as a fusion protein. The further purpose is to isolate the IBV cellular receptor by using the specific binding of SPA with IgG Fc and S1 with the receptor.The major work was summarized as follows:1. Cloning and bioinfomatic analysis of genes of porcine IgG Fc and S1 of IBV...