Production of biologically active feline interferon beta in insect larvae using a recombinant baculovirus.

Feline interferon beta is a cytokine that belongs to the type I IFN family， with antitumor， antiviral and immunomodulatory functions. In this work， recombinant feline interferon beta (rFeIFNβ) was expressed in insect larvae that constitute important agronomic plagues. rFeIFNβ accumulated in the hemolymph of larvae infected with recombinant baculovirus and was purified by Blue-Sepharose chromatography directly from larval homogenates on day 4 post-infection. rFeIFNβ was recovered after purification with a specific activity of 1 × 10 IU mg. By this method， we obtained 8.9 × 10 IU of purified rFeIFNβ per larva. The product was biologically active in vitro， with an antiviral activity of 9.5 × 10 IU mL， as well as a potent antitumor activity comparable to that of the commercial FeIFNω. The glycosylation of rFeIFNβ was confirmed by peptide--glycosidase F digestion. Our findings provide a cost-effective platform for large-scale rFeIFNβ production in laboratory research or veterinary medicine applications.