Strategies for manufacturing soluble human alphainterferons in Escherichia coli: expression, purification, and testing.

Resumo

Escherichia coli has been the favorite expression host for the last decades when it comes to simple recombinant proteins used as biopharmaceuticals. This organism is well-characterized and capable of synthesizing enormous amounts of heterologous polypeptides, especially when no complex post-translational modifications are involved, such as the case of alphainterferons, which are small cytokines used against viral infections and tumors. A significant drawback of this bacterial system is that target molecules are commonly obtained as insoluble and inactive inclusion bodies in the cytoplasm, raising the need for laborious and expensive steps of solubilization and renaturation before the product can be purified. Here, we review past experiences and advances that have delivered IFN-α in its soluble and functional form, including optimization of culture conditions and induction, the use of engineered strains, fusion partners that enhance solubility, and translocation to the periplasm, among others. Also, we assessed downstream processing and analytical techniques that ensured the product’s purity and quality. Finally, we identified some gaps that may represent future opportunities to improve soluble yields.