Recombinant Production of IL-1Ra in Fusion to Albumin Binding Domain for Its Extended Half-Life

Background: Anakinra, a FDA approved biological drug for Rheumatoid Arthritis, must be injected daily due to its short Half-life, leads to the lower patient compliance. So, the aim of this study was to produce IL-1Ra in fusing to albumin binding domain to extend its half-life and evaluate its biological effects. Methods and Results: The expression of IL-1Ra-ABD was performed in E. coli in fusing to intein1 of pTWIN1 in soluble and purified. The affinity of IL-1Ra-ABD to HSA was determined on Native-PAGE and its release percent toward time was determined. Finally, MTT assay was used to determine the antagonizing properties of recombinant IL-1Ra-ABD against IL-1β, on A375 cells. the expression induction of intein1-IL-1Ra-ABD using 0.1mM of IPTG at 15°C, and its cleavage represented a band approximately in 50 and 23 kDa respectively. Native-PAGE results showed that about 78% of IL-1Ra-ABD attached to the HSA after 2 hours of incubation, and MTT assay results showed no significant differences between the effects of our recombinant protein and native IL-1Ra. Conclusion: the production of soluble IL-1Ra-ABD with similar antagonizing effects to IL-1Ra was successfully performed. IL-1Ra-ABD showed suitable interaction with HSA and release over the time. However, pharmacokinetics and furthur biological evaluations are required.