46.    Characterization of an anti-interferon-alpha2b chimeric fusion protein for systemic
          lupus erythematosus therapeutic use

Systemic lupus erythematosus (SLE) is a chronic, multisystem, autoimmune disease that predominantly affects women of childbearing age. Its clinical manifestations (arthritis, rashes, alopecia, vasculitis, nephritis, serositis) lead to significant morbidity, reduced physical function, loss of employment, worse quality of life, high risk of permanent disability and shortened life span. Treatment of SLE remains challenging because of the suboptimal efficacy of standard-of-care medications and the serious adverse events associated with their use. Since the late 70’s, the interferon alpha (IFN-alpha) has been associated with SLE. From that moment, an impressive number of studies have confirmed the importance of IFNalpha in SLE, and have prompted investigation of anti IFN alpha therapeutic strategies. Indeed, several clinical trials have been initiated in SLE using monoclonal antibodies against IFN-alpha. Our group has generated a chimeric anti- IFN-alpha2b fusion protein as a strategy to develop a biotherapeutic for SLE. In this work, we have characterized the anti-IFN-alpha2b chimeric fusion protein produced in different types of mammalian cells in terms of its IFN-alpha affinity, in vitro biological activity and the ability to produce antibodies in transgenic animals. CHOK1 (Chinese Hamster Ovary), HEK293 (Human Embryonic Kidney) and NS0 (derived from murine myeloma) cells were used. The IFN-alpha affinity is in the order of 10-8 M-1. The fusion proteins produced by these different types of cellspresented the ability to neutralize the IFN-alpha antiproliferative and antiviral activities but with differences between them. The best performance was obtained to
the fusion protein produced by CHO-K1 cells. On the other hand, the proteins showed different thermal stability depending on the type of producer cells. In addition, HLA-DR1 transgenic mice inoculated with these fusion proteins generated differential response of anti-anti-IFN-alpha2b antibodies production. The highest antibody title was obtained with the protein derived from HEK293 cells. This characterization allows us to consider the use of an anti-IFN-alpha2b antibody as a potential therapeutic agent for SLE.