Prokaryotic Expression of Porcine Interferon γ and Preparation of Antisera

Objective To express porcine interferon γ(poIFNγ)in prokaryotic cells and prepare the antisera. Methods The gene fragment encoding mature polypeptide of poIFNγ was amplified by PCR and cloned into prokaryotic expression vector pET28a(+). The constructed recombinant plasmid pET-28a-poIFNγ was transformed to E. coli BL21(DE3)for expression under induction of IPTG. The expressed protein was purified and inoculated to mice, and the antisera were prepared and determined for titer by ELISA. Results Both restriction analysis and sequencing proved that recombinant plasmid pET-28a-poIFNγ was constructed correctly. The expressed product, mainly existing in a form of inclusion body, contained 40% of total somatic protein and reached a purity of 90% after purification. The titer of prepared antisera was 10-5. Conclusion Porcine interferon γ was successfully expressed in E. coli, and high titer antisera was prepared.