Human interferon alpha-2 IFNα2 is a cytokine belonging to the family of type I IFNs. IFNα2 is a protein secreted by cells infected by a virus and acting on other cells to inhibit viral infection. The first description of IFNs as a cellular agent interfering with viral replication was made by Alick Isaacs and Jean Lindenmann in 1957. The history of this finding was recently reviewed. There are 3 types of IFNs: Interferon type I, Interferon type II and Interferon type III. The type II IFN, also called IFNγ, is produced by specific cells of the immune system. Unlike type I and type III IFNs, IFNγ has only a modest role in directly restricting viral infections. Type I and type III IFNs act similarly. However, the action of type III IFNs, also known as IFNλ, is limited to epithelial cells while type I IFNs act on all bodys cells.
Type I IFNS form a family of several proteins in the human body there are 13 α subtypes, subtype 1 β 1 ω subtype and other less studied subtypes of κ and ε. Recombinant ifna2 was the first subtype is characterized in the early eighties. The result is recombinant ifna2 is widely used in basic research to elucidate biological activities, structure and mechanism of action of type I IFNS. Recombinant ifna2 was also the first IFN produced by the pharmaceutical industry for use as a drug. Thus, recombinant ifna2 is the most well-known IFN type I subtypes. Properties of recombinant ifna2 is widely shared by other type I IFNS, although there are subtle differences.