Induction and characterization of swine beta interferon.

Newcastle Disease Virus (NDV) strain "H" and Polyinosinic-Polycytidylic acid (Poly I:C) were used for interferon (IFN) induction in secondary pig kidney cells. A functional IFN system was detected and characterized. A wide similarity with the correspondent human and bovine systems was appreciated, with particular regard to the kinetics of synthesis. A glycosylated protein was essential for activity in bovine cells, but not in swine cells. Poly I:C proved to be a very weak inducer, even in conditions which promote IFN synthesis in other cell substrata. beta IFN from secondary pig kidney cells was very effective against Swine Vesicular Disease Virus (SVDV), whereas no activity was detected against porcine Rotavirus; Aujeszky's disease virus, BUK strain, proved to be of intermediate sensitivity. The results of these latter experiments are discussed, with regard to the cells used and to the IFN sensitivity of the tested viruses.