Interferon-gamma receptor (IFNGR)

The interferon-gamma receptor (IFNGR) is a heterodimeric cell surface protein complex composed of two subunits—IFNGR1 and IFNGR2. It specifically binds interferon-gamma, a type II cytokine critical for innate and adaptive immunity. Upon ligand binding, the two subunits associate at the plasma membrane, recruiting JAK family kinases which phosphorylate downstream targets such as STAT1. Activated STAT dimers translocate into the nucleus to drive expression of genes involved in antimicrobial defense, antiviral activity, tumor surveillance, antigen presentation enhancement via MHC class I/II upregulation, macrophage activation, B-cell differentiation signals, and more. The pleiotropic nature makes it central both to host defense against pathogens/cancer and also a potential contributor to inflammatory pathology if dysregulated. Mutations affecting either chain can result in severe immunodeficiency syndromes characterized by heightened susceptibility especially to mycobacterial infections

Other names

Interferon gamma receptorIFN-γ receptorIFNGR1/IFNGR2 complexType II interferon receptor

Agonists such as interferon gamma 1b bind the extracellular domain of the receptor, triggering dimerization and activation of associated Janus kinases (JAK1/JAK2), leading to phosphorylation events that activate STAT transcription factors. This results in upregulation of interferon-stimulated genes involved in immune defense.