Immune (γ) interferon produced by a human T-lymphoblast cell line

Interferons (IFNs) are glycoproteins with antiviral, immunomodulatory and antiproliferative properties. They are classified on the basis of their acid stability, antigenic properties, stimuli for production and cellular origin. IFN-α and IFN-β are acid-stable and derived from leukocytes and fibroblasts. IFN-γ (immune, type II) is acid-labile and generally derived from T lymphocytes. Elaboration of IFN-γ occurs either after sensitized T lymphocytes are exposed to specific antigen or on induction of T lymphocytes with mitogens^1,2. IFN-α and IFN-β have been extensively characterized and much is known about their biochemical properties and gene structure^3-11. In contrast, there is relatively little information available regarding the physical and biological properties of human IFN-γ (refs 1, 2, 12-17). Particular interest in IFN-γ derives from in vitro and in vivo studies which indicate that IFN-γ has greater antiproliferative effects on neoplastic cells than IFN-α and IFN-β (refs 18-21). We report here the production and characteristics of IFN-γ elaborated by a unique human T-lymphoblast cell line.