Cloning And Expression Of Bovine, Chicken, Porcine Interferon-Gamma And Production Of Monoclonal Antibodies

Interferon(IFN), generated by specific cells induced by inducer, is a kind of glycoprotein that possesses high bioactivity and broad-spectrum antiviral activity on the homogeneity animal cells. It is mainly divided into two types, typeⅠand typeⅡ, according to its amino acid sequence, resource and different receptor. TypeⅡis interferon gamma(IFN-γ)that has distinct immunological regulation and anti-tumor function. Due to its enormous regulating function in immune system, IFN-γis a necessary composition in eliminating pathogen by organisim. Accordingly, IFN-γplays an important role in the aspects of diagnosis, therapy and detecting vaccine effect and it is one of the hot spots in the modern molecular biology, immunology and clinical medicine research.In this experiment, recombinant prokaryotic expression plasmids pET30a-IFN-γcontaining bovine,chicken and porcine IFN-γgene that was amplified by PCR were constructed. These primers were designed to eliminate signal regions of the bovine, chicken and porcine IFN-γprotein after amplification. pET30a-IFN-γwas transformed into host bacteria BL21 that were then induced by IPTG. SDS-PAGE was carried to assure recombinant protein expressed by BL21 after purification using Ni-NTA resin. The result was confirmed that bovine, chicken and porcine IFN-γwere expressed in BL21 and all the recombinant proteins were about 25 KD. Rabits were immunized with the recombinant protein emulsified with Freund adjuvant. The antibody titers of serum were determined by indirect enzyme linked immunosorbent assay (ELISA). The results were that the antibody titers of rabit serum immunized by bovine, chicken and porcine IFN-γcombinant protein were 1:1×10~4,1:1×10~6 and 1:1×10~5.