关键词: 牛λ3干扰素, 家蚕杆状病毒表达系统 , 抗病毒活性检测

Abstract: Bovine interferon λ3 (BoIFN-λ3) is a new type of interferon, and it can be employed to prevent and control bovine infectious diseases. Higher expression of BoIFN-λ3 can be achieved in Bombyx mori baculovirus expression system. Firstly, the Kozak sequence was inserted into upstream of optimized BoIFN-λ3 gene, which was cloned to transfer vector pVL1393, and recombinant plasmid of pVL1393-BoIFN-λ3 was constructed. The recombinant silkworm baculovirus with BoIFN-λ3 gene was acquired by employing silkworm baculovirus expression system previously constructed in our laboratory. The recombinant virus was infected with 5th instar larvae of Bombyx mori, and expression product of BoIFN-λ3 was achieved in hemolymph of silkworm. Here a recombinant vesicular stomatitis virus expressing green fluorescent protein (VSV/GFP) and MDBK cells were used to develop an antiviral assay for BoIFN-λ3, and the antiviral activity was about(2.7±0.12)×105 U/mL. Recombinant baculovirus was purified through plaque assay, and antiviral potential expressed by purified baculovirus demonstrated (8.1±0.52)×105 U/mL. The expression efficiency improved by 3 fold. Silkworm-baculovirus expression system is a novel method to produce high quality BoIFN-λ3.

Key words: bovine λ3 interferon, silkworm-baculovirus expression system, antiviral activity assay