ABSTRACT
Interferon-tau (IFN-tau) is a newly discovered IFN of type I. It was originally found for its role as a pregnancy recognition hormone in ruminant animals such as sheep and cows. Like the other type I IFNs, IFN-tau have the same biological activities including antiviral, antiproliferative and immunomodulatory effects. In order to clearly identify the function of IFN-tau, the coding sequence of IFN-tau was amplified by PCR from IFN-tau cDNA, this fragment digested by EcoR I and BamH I and was inserted into pBV220 to form the recombinant plasmid pBV220/IFN-tau which was then transformed into E.coli BL21. It was found that pBV220/IFN-tau was highly expressed as inclusion body in BL21. Next, the expressed protein was purified on S-100 High Resolution and the purified product was confirmed by amino acid sequence analysis. Moreover, the standard antiviral activity test indicated that the activity of IFN-tau was about 2.09?106IU/ml.