Development of IFNβ-1a versions with reduced immunogenicity and full in vitro biological activity for the treatment of multiple sclerosis.

IFNβ (recombinant interferon Beta) has been widely used for the treatment of Multiple sclerosis for the last four decades. Despite the human origin of the IFNβ sequence, IFNβ is immunogenic, and unwanted immune responses in IFNβ-treated patients may compromise its efficacy and safety in the clinic. In this study, we applied the DeFT (De-immunization of Functional Therapeutics) approach to producing functional, de-immunized versions of IFNβ-1a. Two de-immunized versions of IFNβ-1a were produced in CHO cells and designated as IFNβ-1a(VAR1) and IFNβ-1a(VAR2). First, the secondary and tertiary protein structures were analyzed by circular dichroism spectroscopy. Then, the variants were also tested for functionality. While IFNβ-1a(VAR2) showed similar in vitro antiviral activity to the original protein, IFNβ-1a(VAR1) exhibited 40% more biological potency. Finally, in vivo assays using HLA-DR transgenic mice revealed that the de-immunized variants showed a markedly reduced immunogenicity when compared to the originator.