IFN-alpha 16

Interferon alpha-16 (IFN-α16, gene IFNA16, historically also called IFN-αH or leukocyte interferon H) is a member of the human IFN-α subtype family encoded within the type I interferon gene cluster on chromosome 9p22. The mature secreted protein is 166 amino acids in length and, like other IFN-α subtypes, binds the IFNAR1/IFNAR2 heterodimer to trigger JAK1/TYK2-STAT1/STAT2-IRF9 signaling and antiviral ISG induction. IFNA16 carries particular evolutionary and immunological interest: it is one of the primate-specific duplication products of the IFNA locus, and population genetics analyses have identified it as a target of recent positive selection, with variant haplotypes influencing systemic lupus erythematosus susceptibility. Functionally, IFN-α16-containing leukocyte interferon preparations contribute to the inhibition of lymphocyte proliferation, natural killer cell activation and upregulation of MHC antigens. Some commercial and clinical interferon preparations have included IFN-α16 among their constituent subspecies, reflecting the classical approach of using natural leukocyte-derived interferon mixtures before single-subtype recombinant products became standard.