Abstract

The purpose of this study was to express recombinant human interferon lambda3 (rhIFN-λ3) in Escherichia coli, and prepare PEGylated recombinant human interferon lambda3 (PEG-rhIFN-λ3). The rhIFN-λ3 gene was inserted into pThioHisA vector after codon optimization and transformed into E. coli top10 strain, and then it was induced with isopropyl-β-D-thio-galactoside (IPTG). The recombinant protein was subjected to mPEG-ButyrALD modification after dialysis, renaturation and chromatographic purification. Subsequently, the modified product was preliminary isolated and purified for determining its activity. Results show that the recombinant protein was expressed in the form of inclusion bodies. After ion exchange, molecular sieve and other column chromatography purification, the purity of the purified rhIFN-λ3 was as high as 90% and the purity of the mono-PEGylated rhIFN-λ3 after cation-exchange chromatography was as high as 86%. The 50% effective concentration (EC₅₀) of rhIFN-λ3 in WISH cells against vesicular stomatitis virus (VSV) was 8.43 ng/mL, while the EC₅₀ of mono-PEGylated rhIFN-λ3 was 49.19 ng/mL, which reserved 17.14% of the in vitroactivity and supported further studies of this new type of investigational interferon. Further study is needed to better understand the in vivo immunogenicity, antigenicity, stability and antiviral activity of PEG-rhIFN-λ3.

Key words: Recombinant human interferon lambda3, prokaryotic expression, purification, mPEG-ButyrALD, antiviral activity.

Abbreviation

rhIFN-λ3, Recombinant human interferon lambda3; PEG-rhIFN-λ3,PEGylated recombinant human interferon lambda3; IPTG, isopropyl-β-D-thio-galactoside; VSV, vesicular stomatitis virus; EC₅₀, 50% effective concentration.