Ring Finger Protein 215 Negatively Regulates Type I IFN Production via Blocking NF-κB p65 Activation

Germline-encoded pattern recognition receptors (PRRs) recognize molecules frequently found in pathogens (pathogen-associated molecular patterns [PAMPs]) during viral infection. This process induces production of IFNs, leading to expression of IFN-stimulated genes to establish a cellular antiviral state against viral infection. However, aberrant activation of the IFN system may cause immunopathological damage and systemic autoimmune diseases such as systemic lupus erythematosus. Stringent control of IFN signaling activation is critical for maintaining homoeostasis of the immune system; yet, the mechanisms responsible for its precise regulation remain to be elucidated. In this study, we identified that ring finger protein 215 (RNF215), a zinc finger protein, was upregulated by viral infection in human macrophages. In addition, we demonstrated that RNF215 inhibited the production of type I IFNs at least in part via interacting with p65, a subunit of NF-κB, and repressed the accumulation of NF-κB in the promoter region of IFNB1 Moreover, we found that the expression of RNF215 negatively correlated with type I IFNs in patients with systemic lupus erythematosus, indicating that RNF215 plays an important role in the pathogenesis of autoimmune diseases. Collectively, our data identified RNF215 as a key negative regulator of type I IFNs and suggested RNF215 as a potential target for intervention in diseases with aberrant IFN production.