Expression And Antiviral Activity Detection Of Porcine IFBN-α, β, γ

Interferon (IFN) is a kind of cytokine which is induced by particular inducers, secretedby cells. In the same kind of cells, it has the activities of broad-spectrum antivirus, antitumorand regulation of the immune function. Since IFN being discovered, the research of IFN hasbeen one of the most active and fastest developmental fields of cytokine researches. And it isalso the focus of researches about virology, cytology, molecular biology, immunology,oncology and some related fields. Our country has big hog areas. All kinds of porcinediseases, especially the viral diseases, have been very harmful to the development of pigindustry and reduced the economic benefits. The medicine which is efficient but low cost onantivirus and can enhance the effect of immunity will be urgently needed. Based on thefunction of broad-spectrum antivirus, antitumor and immune regulation of porcine IFN, howto be effectively applied to prevent and control porcine diseases has become a key point ofresearch. Porcine IFN is divided into type Ⅰ and type Ⅱ, and at present, α, β, γ are knownand studied widely. IFN-α, β belong to type Ⅰ, which have the effect that inhibiting the virusand antitumor. IFN-γ belongs to type Ⅱ, is also involved in the expression of the majorhistocompatibility complex (MHC) antigen of cells and reaction of immune regulation,except the antiviral effect. And it plays an important role in immune regulation.In this study, the main purpose is to explore the effect of prokaryotic and eukaryoticexpressed recombinant porcine IFN protein that inhibits the proliferation of different viruseson different cell lines. With pGEX-6p-1vector, the prokaryotic expression vectors of porcineIFN-α, β, γ genes were constructed. And after induction, the prokaryotic recombinant porcineIFN proteins were available and purified after that. After immunization of BALB/c mice withporcine IFN, the polyclonal antibodies against porcine IFN-α, β, γ were prepared, the titer ofwhich can be above1:10,000. After ligation of porcine IFN-α, β, γ genes and pFastBacTMHTB vector, porcine IFN were successfully expressed in sf9cells with Bac-To-Bacbaculovirus expression system. Then with the cytopathic effect reduction assay (CPEI), theantiviral activities of prokaryotic and eukaryotic expressed porcine IFN-α, β, γ were detectedin PRRSV/Marc-145and VSV/MDBK systems. Results show that, there are significant activities of prokaryotic and eukaryotic expressed porcine IFN-α, β, γ against PRRSV andVSV. The antiviral activities of porcine IFN-α is about2times as much as which of porcineIFN-β,2-6times as much as which of porcine IFN-γ. And the antiviral activities ofeukaryotic expressed porcine IFN in sf9cells is1-4times as much as which of prokaryoticexpressed porcine IFN. In the study of antiviral activities detection, the activities ofrecombinant porcine IFN-α, β, γ against PRRSV can reach105-106U/mg. It indicates that, theexpressed recombinant porcine IFN have the potential of becoming the protein drugs to treatporcine reproductive and respiratory syndrome and other porcine diseases.