Targeted mutations in Val101 and Arg27 interferon beta protein increase its transcriptional and translational activities

Abstract

Interferon beta (IFN beta) is the most prescribed drug that has been used frequently for the treatment of multiple sclerosis (MS) patients. The aim of this study is to improve the production of IFN beta by induction of site directed mutagenesis. Accordingly, recombinant constructs were designed in order to enhance the expression of IFN beta mRNA and protein. The recombinant plasmids were transfected to the CHO cell line, following RNA extractions and cDNA synthesis. The effects of recombinant constructs were analyzed by real time PCR, ELISA and MTT assay. Transfected samples with either IFN beta(101) or IFN beta(101+27) have shown 11.55 and 2.26 fold elevation and over-expression compare to the wild type construct respectively. Our data also indicated that the IFN beta(101) and IFN beta(101+27) constructs increase IFN beta protein expression more than 2.2 and 4.5 fold, respectively compared to the control group. It could be concluded that the substitution of Phe in the codon 101 position, which may increase the binding activity of IFN beta with its receptors and introduction of an additional N glycosylation site (Asn-X-Thr) in the position 27 of IFN beta protein may cause such an effect. The proliferative activity of transfected cells by a recombinant IFN beta(101) decreases in comparison to the wild type, although it was not statistically significant. Over-expression of IFN beta in such a level is promising not only for the patients but also for the pharmaceutical industries. (C) 2015 Elsevier Ltd. All rights reserved.