en 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 Medical Biotechnology Medical Biotechnology مقاله کامل Full Length/Original Article <p><strong>Background:</strong> Cancer immunotherapy is a promising strategy for cancer treatment. In this strategy, &nbsp;&nbsp;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. <strong>Methods:</strong> 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 <em>E. coli</em> <em>Rosetta</em> (DE3) and secreted into the periplasm. <strong>Results:</strong> The analysis of<em> in vitro </em>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. <strong>Conclusion:</strong> The current study provides an alternative strategy to extend the half-life and improve pharmacokinetic properties of rIL-2 without reducing its bioactivity <em>in vitro</em>.</p> Albumin, Albumin-binding domain, Bioactivity, Fusion protein, Interleukin 2, Pharmacokinetics, Serum half-life 77 83 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-1-634&slc_lang=en&sid=1 Elham Adabi No Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran Fateme Saebi No Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran Amin Moradi Hasan-Abad No Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran Ladan Teimoori-Toolabi No Molecular Medicine Department, Pasteur Institute of Iran, Tehran, Iran Gholam Ali Kardar gkardar@tums.ac.ir Yes Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran