Evaluation of an Albumin-Binding Domain Protein Fused to Recombinant Human IL-2 and Its Effects on the Bioactivity and Serum Half-Life of the Cytokine

Adabi, Elham; Saebi, Fateme; Moradi Hasan-Abad, Amin; Teimoori-Toolabi, Ladan; Kardar, Gholam Ali

doi:10.18869/acadpub.ibj.21.2.77

Evaluation of an Albumin-Binding Domain Protein Fused to Recombinant Human IL-2 and Its Effects on the Bioactivity and Serum Half-Life of the Cytokine

Authors

Elham Adabi ¹

Fateme Saebi ¹

Amin Moradi Hasan-Abad ¹

Ladan Teimoori-Toolabi ²

Gholam Ali Kardar ¹

¹ Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran

² Molecular Medicine Department, Pasteur Institute of Iran, Tehran, Iran

10.18869/acadpub.ibj.21.2.77

Abstract

Background: Cancer immunotherapy is a promising strategy for cancer treatment. In this strategy, the immune system is triggered to destroy cancer cells. IL-2 is an important factor in passive cancer immunotherapy that helps modulating some important immune functions. One of the IL-2 limitations is low serum half-life; therefore, repetitive high doses of the injections are required to maintain effective concentrations. High-dose IL-2 therapy results in severe side effects; thus, improvement of its serum half-life would provide therapeutic benefits. Methods: We have investigated a strategy that is able to utilize an albumin-binding domain (ABD) from streptococcal protein G. In this strategy, the fusion protein ABD-rIL-2 binds to serum albumin, which results in improvement of the IL-2 serum half-life. PET26b+ plasmid was used as an expression vector, which encoded rIL-2 and ABD-rIL-2 both fused to pelB secretion signal under the control of the strong bacteriophage T7 promoter. The constructs were expressed in E. coli Rosetta (DE3) and secreted into the periplasm. Results: The analysis of in vitro bioactivity proved that the fusion of ABD to rIL-2 does not interfere with its bioactivity. ABD-rIL-2 fusion protein indicated higher serum half-life compared to rIL-2, when it was tested in the BALB/c mice. Conclusion: The current study provides an alternative strategy to extend the half-life and improve pharmacokinetic properties of rIL-2 without reducing its bioactivity in vitro.

Keywords

Albumin

Albumin-binding domain

Bioactivity

Fusion protein

Interleukin 2

Pharmacokinetics

Serum half-life