IFN-γ (3F1E3) Mouse mAb #3159

IFN-γ plays key roles in both the innate and adaptive immune response. IFN-γ activates the cytotoxic activity of innate immune cells, such as macrophages and NK cells (1,2). IFN-γ production by NK cells and antigen presenting cells (APCs) promotes cell-mediated adaptive immunity by inducing IFN-γ production by T lymphocytes, increasing class I and class II MHC expression, and enhancing peptide antigen presentation (1). Due to differences in the degree of glycosylation, there are three forms of IFN-γ, with approximate molecular weights of 25, 20, and 15.5 kDa by SDS-PAGE (5). The anti-viral activity of IFN-γ is due to its induction of PKR and other regulatory proteins. Binding of IFN-γ to the IFNGR1/IFNGR2 complex promotes dimerization of the receptor complexes to form the (IFNGR1/IFNGR2)₂ -IFN-γ dimer. Binding induces a conformational change in receptor intracellular domains and signaling involves Jak1, Jak2, and Stat1 (3). The critical role of IFN-γ in amplification of immune surveillance and function is supported by increased susceptibility to pathogen infection by IFN-γ or IFNGR knockout mice and in humans with inactivating mutations in IFNGR1 or IFNGR2. IFN-γ also appears to have a role in atherosclerosis (4).

IFN-γ, also known as type II interferon, is produced mainly in activated T lymphocytes and natural killer cells (4) and has broad effects on various cells of the immune system. Many signaling proteins including IL-2, FGF, and EGF induce the synthesis of IFN-γ.