The Immunity Power Of PRRSV Structural Proteins In Mice

Aim Compare the immune response induced by4different envelope proteins ofporcine reproductive and respirety syndrome virus (PRRSV) and the immune responsestimulated by single envelop protein or protein mixture. Identify the immunity ofthose protein and protein mixture and hope to find the efficient way to make a subunitvaccine to against PRRSV infection.Methods Express the4kinds of envelope protein of PRRSV in E.Coli.Immunize Balb/C mice with those envelope proteins and investigate the immuneresponse sitimulated by a single envelope. Mix the envelop protein by different ways,after immunize the Balb/C mice, the antibody titer of mice sera of two proeins group,three protein group and four protein group were investigated by ELISA assay.Results The result shown that the4envelop protein (GP2, GP3, GP4, GP5) ofPRRSV expressed by E.coli can be detected by SDS-PAGE and Western blotting testafter purification. After those proteins were purified, the single protein group, twoproteins combination group, three proteins combination group and four proteinscombination group were used to immunize Balb/c mice. The antibody titer ofimmunized mice sera were detected by ELISA and the result shown that, in singleprotein group, GP5has the highest power to induce immune response in mice. In twoprotein group, three proteins combination group and four proteins combination group,GP2+GP3, GP2+GP4, GP3+GP4, or GP2+GP3+GP4demonstrited significantly highertiters of antibodies against PRRSV and induced strong cellular immune responsecompared to mice immunized with GP2, GP3, or GP4alone. Forethermore, the proteincombinated group (GP5+GP4, GP5+GP3, GP5+GP2, GP5+GP4+GP3, GP5+GP4+GP2and GP5+GP3+GP2) could induce higher humerol immune response than GP2, GP3,GP4or GP5alone. It was also found that the GP5group could induce the same antibodyresponse as GP2+GP3+GP4dose.Conclusion The envelop protein can be expressed in E.Coli sussfuly. In sigleprotein group, all the envelope protein had the ablity to sitimulate immne system toresponse and GP5could induce the highest antibody response. In protein combinationgroup, the protein mixture contain the GP5could induce highest immune response andthe group without GP5(GP4+GP3+GP2group) could induce the same level of immuneresponse as sigle GP5dose.