Full name: Interferon gamma

Aliases:1 IFG, IFI, and IMD69

Size:2 40–60 kDa

Family:1,3 Only member of the type II IFN class

Receptors:2,3 IFNGR1/IFNGR2

Major cellular sources:2 NK cells, NKT cells, macrophages, myelomonocytic cells, Th1 cells, cytotoxic T lymphocytes, and B cells

Major cellular targets:2 Epithelial cells, macrophages, DCs, NK cells, T cells, and B cells

Disease states associated with:2 Rheumatoid arthritis, atopic dermatitis, and pathogenic infections

Major physiologic functions:

  • High IFN-γ levels are expressed by Th1 cells, activating macrophages for direct antimicrobial and antitumor activity.2,3

  • IFN-γ regulates immunoglobulin production, class switching in B cells, NK cell activity, MHC class I and class II protein expression, and antigen presentation.2,3

  • Aside from functions in host defense, IFN-γ may contribute to autoimmune pathology. IFN-γ production is controlled most notably by IL-12 and IL-18 cytokines, which serve as a bridge to link infection with IFN-γ production in innate immune response and to further increase IFN-γ production.3

  • Negative regulators of IFN-γ production include IL-4, IL-10, transforming growth factor-β, and glucocorticoids.3

  • IFN-γ primarily signals through the JAK-STAT pathway, and IFN-γ–induced JAK-STAT signaling is considered the global paradigm for class II cytokine receptor signal transduction.3

IFG: interferon gamma; IFN: interferon; IFNGR: IFN-γ receptor; IL: interleukin; JAK: Janus kinase; MHC: major histocompatibility complex; NK: natural killer; NKT: natural killer T; STAT: signal transducer and activator of transcription; Th: T helper; DCs: dendritic cells


  • 1.

    NCBI. Gene. IFNG interferon gamma [Homo sapiens (human)]. www.ncbi.nlm.nih.gov/gene/3458. Accessed March 11, 2021.

  • 2.

    Akdis M, Aab A, Altunbulakli C, et al. J Allergy Clin Immunol. 2016;138:984-1010.

  • 3.

    Schroder K, Hertzog PJ, Ravasi T, Hume DA. J Leukoc Biol. 2004;75:163-189.