Immune regulation role of IFN-γ in Acipenser sinensis

Acipenser sinensis belongs to the cartilaginous fish, which is between the cartilaginous fishes and teleost fishes. It is an important branch point in the evolutionary tree of the biological immune system. It is a living fossil for the study of the evolution of fish and vertebrates, and plays an extremely important role in the evolutionary history of fish and vertebrates. In order to understand the immunomodulatory effect of A. sinensis IFN-γ, IFN- γ sequence was obtained by transcriptome of A. sinensis, the recombinant plasmid of pTRI-st-IFNg was constructed and transformed into the BL21 Escherichia coli for expression and expressed in competent prokaryotic cells. SDS-PAGE analysis showed that the size of IFN-γ recombinant protein was 19.17 ku, and the concentration was 0.998 mg/mL. Quantitative PCR showed that the antiviral genes Mx, Viperin, CXCL11-L1,CXCL11-L2 (CXC subfamily of chemokines) and antiviral protein Epithelioma papulosum cyprini cells (EPC) P,N,G were induced, which indicated that IFN-λ activated antiviral activity. Additionally, spring viremia of carp virus (SVCV) replication as well as the production of cytopathic effect (CPE) was significantly inhibited. Results of incubation with Aeromonas hydrophila, A. intermedia and A. veronii showed a significant inhibition on their growth and activity. In conclusion, this study provides partial theory for the understanding of IFN-γ bioactivity in A. sinensis.