Lin, You-ShengYou-ShengLinChang, Yung-ChiYung-ChiChangTAI-LING CHAOTsai, Ya-MinYa-MinTsaiJhuang, Shu-JhenShu-JhenJhuangHo, Yu-HsinYu-HsinHoLai, Ting-YuTing-YuLaiLiu, Yi-LingYi-LingLiuChen, Chiung-YaChiung-YaChenTsai, Ching-YenChing-YenTsaiHsueh, Yi-PingYi-PingHsuehSUI-YUAN CHANGChuang, Tsung-HsienTsung-HsienChuangCHIH-YUAN LEELI-CHUNG HSU2023-08-092023-08-092023-08-070022-10071540-9538https://scholars.lib.ntu.edu.tw/handle/123456789/634492Type I interferons are important antiviral cytokines, but prolonged interferon production is detrimental to the host. The TLR3-driven immune response is crucial for mammalian antiviral immunity, and its intracellular localization determines induction of type I interferons; however, the mechanism terminating TLR3 signaling remains obscure. Here, we show that the E3 ubiquitin ligase ZNRF1 controls TLR3 sorting into multivesicular bodies/lysosomes to terminate signaling and type I interferon production. Mechanistically, c-Src kinase activated by TLR3 engagement phosphorylates ZNRF1 at tyrosine 103, which mediates K63-linked ubiquitination of TLR3 at lysine 813 and promotes TLR3 lysosomal trafficking and degradation. ZNRF1-deficient mice and cells are resistant to infection by encephalomyocarditis virus and SARS-CoV-2 because of enhanced type I interferon production. However, Znrf1-/- mice have exacerbated lung barrier damage triggered by antiviral immunity, leading to enhanced susceptibility to respiratory bacterial superinfections. Our study highlights the c-Src-ZNRF1 axis as a negative feedback mechanism controlling TLR3 trafficking and the termination of TLR3 signaling.enThe Src-ZNRF1 axis controls TLR3 trafficking and interferon responses to limit lung barrier damagejournal article10.1084/jem.20220727371589822-s2.0-85159727903https://api.elsevier.com/content/abstract/scopus_id/85159727903