Cloning and biologic activities of a bovine interferon-alpha isolated from the epithelium of a rotavirus-infected calf

A cDNA encoding a distinct bovine (Be) interferon (IFN) alpha, designated BoIFN-alpha E, was generated from gut epithelial cells isolated from a rotavirus-infected calf. The BoIFN-alpha E cDNA sequence shared a greater than 90% identity with the other BoIFN-alpha subtypes, The cDNA encoding BolFN-alpha E has been expressed in insect cells using the baculovirus Autographa californica nuclear polyhedrosis virus (AcMNPV) as a vector. Insect cells infected with recombinant virus secreted a protein with a relative molecular mass of 19,500 into the culture medium not observed in cells infected with wild-type AcMNPV, Supernatants harvested from cultures of insect cells infected with the recombinant AcMNPV encoding IFN-alpha E inhibited the replication of Semliki Forest virus in a bovine cell line and typically showed 10(6) dilution units/ml of antiviral activity, However, differences were observed between the activities of recombinant BoIFN-alpha E and BoIFN-alpha(1) 1 on the proliferation of WC1(+) gamma/delta T cells, Purified (> 99%) WC1(+) gamma/delta T cells failed to proliferate to IFN-alpha(1) 1 or concanavalin A and IFN-alpha E acted as a weak proliferative signal to these cells, demonstrating a functional difference between two closely related BoIFN-alpha subtypes.