Activates inducible nitric oxide synthase (iNOS)
Induces the production of IgG2a and IgG3 from activated plasma B cells
Causes normal cells to increase expression of class I MHC molecules as well as class II MHC on antigen-presenting cells—to be specific, through induction of antigen processing genes, including subunits of the immunoproteasome (MECL1, LMP2, LMP7), as well as TAP and ERAAP in addition possibly to the direct upregulation of MHC heavy chains and B2-microglobulin itself
Promotes adhesion and binding required for leukocyte migration
Induces the expression of intrinsic defense factors—for example, with respect to retroviruses, relevant genes include TRIM5alpha, APOBEC, and Tetherin, representing directly antiviral effects
Primes alveolar macrophages against secondary bacterial infections.IFN-γ is the primary cytokine that defines Th1 cells: Th1 cells secrete IFN-γ, which in turn causes more undifferentiated CD4+ cells (Th0 cells) to differentiate into Th1 cells
, representing a positive feedback loop—while suppressing Th2 cell differentiation. (Equivalent defining cytokines for other cells include IL-4 for Th2 cells and IL-17 for Th17 cells.) NK cells and CD8+ cytotoxic T cells also produce IFN-γ. IFN-γ suppresses osteoclast formation by rapidly degrading the RANK adaptor protein TRAF6 in the RANK-RANKL signaling pathway, which otherwise stimulates the production of NF-κB. Activity in granuloma formation
A granuloma is the bodys way of dealing with a substance it cannot remove or sterilize. Infectious causes of granulomas (infections are typically the most common cause of granulomas) include tuberculosis, leprosy, histoplasmosis, cryptococcosis, coccidioidomycosis, blastomycosis, and toxoplasmosis.
In 2002, the manufacturer InterMune issued a press release saying that phase III data demonstrated survival benefit in IPF and reduced mortality by 70% in patients with mild to moderate disease. The U.S. Department of Justice charged that the release contained false and misleading statements. InterMunes chief executive, Scott Harkonen, was accused of manipulating the trial data, was convicted in 2009 of wire fraud, and was sentenced to fines and community service. Harkonen appealed his conviction to the U.S. Court of Appeals for the Ninth Circuit, and lost. Harkonen was granted a full pardon on January 20, 2021.Preliminary research on the role of IFN-γ in treating Friedreichs ataxia (FA) conducted by Children’s Hospital of Philadelphia has found no beneficial effects in short-term (< 6-months) treatment. However, researchers in Turkey have discovered significant improvements in patients gait and stance after 6 months of treatment.Although not officially approved, Interferon-γ has also been shown to be effective in treating patients with moderate to severe atopic dermatitis. Specifically, recombinant IFN-γ therapy has shown promise in patients with lowered IFN-γ expression, such as those with predisposition to herpes simplex virus, and pediatric patients. Potential use in immunotherapy
IFN-γ increases an anti-proliferative state in cancer cells, while upregulating MHC I and MHC II expression, which increases immunorecognition and removal of pathogenic cells. IFN-γ also reduces metastasis in tumors by upregulating fibronectin, which negatively impacts tumor architecture.IFN-γ is not approved yet for the treatment in any cancer immunotherapy.