Type I Interferons in the Pathogenesis and Treatment of Sjögren’s Syndrome: An Update

Type I interferons (IFN) are widely expressed cytokines that play a pivotal role in the cell-intrinsic antimicrobial process, especially in viral infections. Studies have shown an increased expression of Type I IFNs and their induced genes in peripheral blood cells and exocrine glands from patients with Sjögren’s syndrome (SS), indicating that the Type I IFN pathway a vital role in the pathogenesis of this disease. The source of upregulated Type I IFNs in patients with SS is unknown. Many cells were reported to contribute to the process, especially plasmacytoid dendritic cells and other innate immune cells. The activation of Type I IFN signalling was regulated by both genetic and epigenetic pathways, suggesting that genetic predisposition and environmental factors may affect the initiation and progression of SS. Treatments targeting the Type I IFN pathway are still under evaluation and more results are needed to see their value. The authors’ review aims to summarise the functions and regulations of Type I IFNs in the pathogenesis of SS. They also summarise current treatments (including clinical trials) targeting the Type I IFN pathway in treating SS and provide potential targets for future studies.