PD63-02 UROPATHOGENIC E. COLI SUPPRESSES BACTERIAL DNA-INDUCED ACTIVATION OF cGAS-STING SIGNALING AND TYPE I INTERFERON SECRETION

You have accessJournal of UrologyInfections/Inflammation/Cystic Disease of the Genitourinary Tract: Kidney & Bladder II (PD63)1 May 2024PD63-02 UROPATHOGENIC E. COLI SUPPRESSES BACTERIAL DNA-INDUCED ACTIVATION OF cGAS-STING SIGNALING AND TYPE I INTERFERON SECRETION Yan Liu, Hongying Huang, Herbert Lepor, Xue-Ru Wu, and Ellen Shapiro Yan LiuYan Liu , Hongying HuangHongying Huang , Herbert LeporHerbert Lepor , Xue-Ru WuXue-Ru Wu , and Ellen ShapiroEllen Shapiro View All Author Informationhttps://doi.org/10.1097/01.JU.0001009384.23104.ca.02AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: During urinary tract infection (UTI), urothelial cells recognize pathogen-associated molecular patterns such as nucleic acid, lipopolysaccharide, and FimH and initiate innate immune defense against uropathogenic E.coli (UPEC). As the major pathogen DNA sensing mechanism, cyclic GMP-AMP synthase (cGAS) recognizes cytosolic DNA from invading microbes and activates stimulator of interferon genes (STING), leading to the release of type I interferons (IFNs) and proinflammatory cytokines. However, whether the cGAS-STING signaling is functional in urothelial cells and how UPECs interact with the pathway remains elusive. The study investigated the role of cGAS-STING signaling in UTI. METHODS: The protein and mRNA expression of cGAS and STING in human bladder tissues was examined by immunostaining and RNA-seq. Bacterial genomic DNA was extracted by a Microbiome DNA purification kit. Pathogen DNA was transfected into T24 human urothelial cells by lipofectamine. STING gene expression was knocked down by specific siRNA. T24 cells were challenged by a UPEC strain UTI89 and lab strain HB101 at a multiplicity of infection of 10. The gene and protein expression were evaluated with qRT-PCR and ELISA. RESULTS: The cGAS and STING stained all the layers of the human urothelium. RNA-seq detected an average normalized transcript of 17.7 per million for STING and 4.1 for cGAS. Transfection with genomic DNA from a UPEC strain UTI89 into T24 cells triggered 10.8 fold higher expression of IFNβ, 6.2 fold of IFNα, 26 fold of IFNκ, and 1.7 fold of TNFα than the controls. Knockdown of STING gene expression completely abolished the basal expression of IFNβ and IFNα and drastically reduced IFNκ and TNFα expression. Following transfection of UTI89 genomic DNA, the induced expression of IFNβ, IFNα, IFNκ, and TNFα in STING-knockdown T24 cells was four, two, sixteen, and seven times lower, respectively, than that in control cells. The challenge with UTI89 reduced 75% of IFNβ expression, 96% of IFNα, and 92% of IFNκ but elicited 3.6 fold higher expression of TNFα, while a lab strain HB101 did not exert significant changes. Moreover, after bacterial DNA transfection, infection with UTI89 suppressed 90% of DNA-triggered IFNβ expression, 96% of IFNα, 76.6% of IFNκ, and 87% of TNFα in T24 cells. CONCLUSIONS: Urothelial cells recognize cytosolic UPEC DNA and activate the cGAS-STING cascade to release type I IFNs and cytokines. UPECs have evolved to suppress the cGAS-STING activation. Countering UPEC immune subversion holds the therapeutic potential for an enhanced immune defense against UTI. Source of Funding: None © 2024 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 211Issue 5SMay 2024Page: e1292 Advertisement Copyright & Permissions© 2024 by American Urological Association Education and Research, Inc.Metrics Author Information Yan Liu More articles by this author Hongying Huang More articles by this author Herbert Lepor More articles by this author Xue-Ru Wu More articles by this author Ellen Shapiro More articles by this author Expand All Advertisement PDF downloadLoading ...