Interferon alpha receptor 1 (IFNAR1)

Interferon alpha receptor 1 (IFNAR1) is a critical subunit of the heterodimeric Type I Interferon Receptor complex, which also includes IFNAR2. This receptor is expressed on the surface of most nucleated cells and serves as the primary docking site for type I interferons, including IFN-alpha and IFN-beta. Upon ligand binding, IFNAR1 associates with Janus kinase 1 (JAK1) and Tyrosine kinase 2 (TYK2), triggering the JAK-STAT signaling pathway to induce an antiviral state and modulate immune responses. In many autoimmune diseases, particularly systemic lupus erythematosus (SLE), there is a chronic overproduction of type I interferons leading to persistent receptor activation and tissue damage. Therapeutic targeting of IFNAR1, most notably by the monoclonal antibody anifrolumab, allows for the broad inhibition of all type I interferon signaling, providing a potent mechanism to reduce disease activity in patients with interferon-mediated pathologies.

Other names

Interferon-alpha/beta receptor alpha chainIFN-alpha/beta receptor 1Type I interferon receptor 1Cytokine receptor class-II member 1CRF2-1

Anifrolumab is a human monoclonal antibody that binds to the IFNAR1 subunit of the type I interferon receptor, thereby inhibiting the signaling of all type I interferons (IFN-alpha, IFN-beta, IFN-kappa, IFN-omega, and IFN-epsilon). By blocking this receptor, the drug prevents the activation of the JAK-STAT pathway and the subsequent transcription of interferon-responsive genes, which are often overexpressed in autoimmune conditions like systemic lupus erythematosus (SLE).