Recombinant CD137‐Fc, its synthesis, and applications for improving the immune system functions, such as tumor immunotherapy and to reduce the inflammation due to the novel coronavirus

Ajami, Maryam; Nazari, Mahboobeh; mahmoodzadeh, Habibollah; Moazzeni, Seyed Mohammad

CD137 (ILA/4‐1BB), a member of tumor necrosis factor receptor superfamily, is one of the most important T cell costimulatory molecules. Interaction of this molecule with its ligand transmits a two‐way signal that activates both T lymphocyte and antigen presenting cells. The soluble form of CD137 (sCD137) reduces the activity of its membrane isoform and is associated with T lymphocyte activation‐induced cell death. Recombinant CD137‐Fc may be used to treat cancers, autoimmune disorders and viral infections. It may also be useful for management of coronavirus infection. The 1276 bp DNA sequence encoded CD137‐Fc recombinant protein was prepared and subcloned into lentiviral vector and expressed in transduced CHO‐K1 eukaryotic cells. The sodium dodecyl sulfate–polyacrylamide gel electrophoresis, Western blot analysis, and enzyme‐linked immunosorbent assay analysis results demonstrated that the expression of the 70‐kDa CD137‐Fc molecule was detectable without any degradation. This study helps to confirm previous research suggesting the use of this recombinant protein as a promising solution for the treatment of virus infections. CD137‐Fc fusion protein could also make immunotherapy more effective for some diseases. This product is widely used in novel medical treatments, including cell‐based immunotherapy such as dendritic cell, CAR T and CAR NK therapy. Its production and usage in research and treatment is noticeable also in current coronavirus disease 2019 pandemic.