A monoclonal antibody as therapeutic candidate to neutralize a broad diversity of human IFN alfa subtypes

DEPETRIS, M.; OGGERO EBERHARDT, M.; CASALIS, P.; KRATJE, R. B.; ETCHEVERRIGARAY, M.

La Habana. Cuba

Simposio; BIOTECNOLOGÍA HABANA 2006: Aplicaciones Médicas de la Biotecnología; 2006

Centro de Ingeniería Genética y Biotecnología (CIGB)

Even though ytokines has a significant role in sustaining normal physiology their excessive production may cause pathological conditions Thus, the increased expression of human interferon alpha (hIFN-alfa) is associated with several autoimmune illnesses where the cytokine may be a factor of either initiating or maintaining the disease. Nowadays, several monoclonal antibodies (mAbs) have been approved for human use or are in late stages of clinical trials, representing IFN-alfa an attractive target for antibody based therapy. A panel of 11 murine mAbs was prepared using recombinant hIFN alfa2b as immunogen. All of them bound to the native form of the cytokine with affinity constants ranging from 1,7.107 M-1 to 1,4.1010 M-1. An epitope mapping protocol demonstrated four spatially distinct areas of the protein recognized by the mAbs. Taking into account the characterization of the antibodies and their ability to inhibit the IFN-alfa biological activity, four mAbs were selected to produce scFv fragments. One of these fragments (CA5E6) was able to neutralize a wide spectrum of the subtypes of IFN alfa family, including the recombinant cytokines hIFN alfa2a and hIFN alfa2b and an heterogeneous collection of IFN alfa produced by activated leukocytes and Namalwa cells. Consequently, the selected scFv CA5E6 represents an efficient molecule that neutralizes a broad diversity of IFN-alfa subtypes in order to be used in the treatment of diseases such as systemic lupus erythematosus, multiple sclerosis and rheumatoid arthritis.