IFNn

IFNn, also known as IFN-lambda or IL-29, is a member of the Type II interferon family, which is distinct from Type I (classical interferons like IFN-alpha and IFN-beta) and Type II (IFN-gamma). IFNn plays a crucial role in the innate immune response, particularly in antiviral defense at mucosal surfaces. Unlike other interferons that are produced by a wide range of cells, IFNn is primarily expressed by epithelial cells, such as those lining the respiratory and gastrointestinal tracts.

IFNn exerts its antiviral effects by inducing the expression of interferon-stimulated genes (ISGs) within target cells. These ISGs encode proteins that can inhibit viral replication through various mechanisms, including blocking viral entry, interfering with viral RNA synthesis, and promoting cellular defense pathways. A key characteristic of IFNn is its signaling pathway. It primarily signals through a receptor composed of the IL28R1 and IL10R2 subunits. This receptor complex is distinct from the receptor used by Type I interferons.

The production of IFNn is triggered by the detection of viral components by pattern recognition receptors within epithelial cells. This localized production at mucosal barriers is thought to provide an early line of defense against invading pathogens. Research into IFNn has highlighted its potential therapeutic applications, particularly in treating viral infections of the respiratory tract, such as hepatitis C virus (HCV) and respiratory syncytial virus (RSV). Its specific targeting of epithelial cells and its potent antiviral activity make it an attractive candidate for further development as an immunomodulatory drug.