Biological activity of recombinant bovine interferon τ using an Autographa californica nuclear polyhedrosis virus expression system

Bovine interferon (bIFN) τ which plays a key role in maternal-fetal recognition of pregnancy, was expressed by an Autographa californica nuclear polyhedrosis virus expression system. cDNA coding bIFNτ was derived from cultured trophoblast cells. The recombinant (r) bIFNτ had high antiviral activity (1 × 10⁸ IU/mg) and the molecular weight of rbIFNτ was estimated to be 23 kDa by Western blotting analysis. We investigated the biological effect of rbIFNτ on prostaglandin (PG) p_2α synthesis in cultured bovine endometrial epithelial cells in the presence or absence of oxytocin (OT, 100 nM). rbIFNτ suppressed basal and OT-induced PGF_2α production in a dose-dependent manner (1-1,000 ng/ml). These results showed that biologically active rbIFNτ was produced in the baculovirus expression system, and that rbIFNτ had the ability to suppress the synthesis of PGF_2α from bovine endometrial epithelial cells.