High yield expression and secretion of the ovine pregnancy recognition hormone interferon-tau by Pichia pastoris.

The early conceptus (embryo and associated membranes) of domestic ruminats signals its presence to the maternal uterus through production of interferon-tau (IFN-tau). Production of IFN-tau ensures continued production of progesterone, the hormone of pregnancy, by the ovarian corpus luteum. This paper reports the high-level expression and efficient secretion of biologically active recombinant ovine IFN-tau (rOvIFN-tau) by Pichia pastoris. The developed method produces more than 80% pure recombinant ovine IFN-tau, obviating the need for further purification for many purposes. Initial fermentation studies produced IFN-tau at 280 mg/liter and demonstrate the potential of this system for large-scale production of IFN-tau.