Over-expression and single-step purification of human IFNα8 and human IFNα2b reveals the highest antiviral activity of human IFNα8

Background Human alpha interferons (HuIFNα) comprise a multigene family, originally identified as proteins responsible for the induction of cellular resistance to viral infections, subdivided into 13 different subtypes (IFNα1, α2, α4, α5, α6, α7, α8, α10, α13, α14, α16, α17 and α21). The genes that encode these proteins are clustered on chromosome 9 in human [1]. There have been reports of obvious differences in the relative biologicals activities among IFNα subtypes [2,3] and it was found that the activity varied greatly depending on the target cells, the IFNα subtypes and even if the proteins were compared on base of both units of biological activity or mass [4]. The HuIFNα2b and HuIFNα8 are among the IFN subtypes with highest antiviral activity. The first one was licensed by the Food and Drug Administration in 1986 (USA) for the treatment of hairy cell leukemia [5]. On the other hand, the HuIFNα8 has shown the highest biological activity in several in vitro assays [6-8].