In vitro biological activities of Escherichia coli-derived bovine interferons-alpha, -beta, and -gamma.

The infectious yields of several bovine viruses were inhibited in bovine cells treated with purified preparations of E. coli-derived bovine interferons (BoIFNs)-alpha, -beta, and -gamma. BoIFN-beta 2, encoded by one member of the BoIFN-multigene family, had more potent antiviral and antiproliferative activities than the product of one member of the class-I IFN-alpha gene family (BoIFN-alpha I1). BoIFN-beta 2 also completed more effectively than BoIFN-alpha I1 with HuIFN-alpha I2 for cell-surface receptors on bovine cells. Despite these differences, the kinetics of maximal antiviral activity were similar for BoIFN-alpha I1, BoIFN-beta 2, and HuIFN-alpha I2. In comparison to BoIFN-alpha I1 and BoIFN-beta 2, BoIFN-gamma had the least in vitro antiviral activity and required the longest contact with cells to achieve maximal protection against virus infection, but had a dramatically greater antiproliferative activity.