Journal of Experimental Pharmacology (Nov 2023)
Synergistic Effects of Azithromycin and STING Agonist Promote IFN-I Production by Enhancing the Activation of STING-TBK1 Signaling
Abstract
Kanoktip Petcharat,1 Narongsuk Munkong,2 Rungthip Thongboontho,1 Widsanusan Chartarrayawadee,3 Arthid Thim-Uam1 1Division of Biochemistry, School of Medical Sciences, University of Phayao, Phayao, 56000, Thailand; 2Department of Pathology, School of Medicine, University of Phayao, Phayao, 56000, Thailand; 3Division of Chemistry, School of Science, University of Phayao, Phayao, 56000, ThailandCorrespondence: Arthid Thim-Uam, Division of Biochemistry, School of Medical Sciences, University of Phayao, Phayao, 56000, Thailand, Tel +668 6 216 26 33, Email [email protected]; [email protected]: Azithromycin (AZM) is a macrolide antibiotic that exhibits anti-inflammatory and anti-viral infection properties by enhancing type-I interferon (IFN-I) responses. The stimulator of interferon genes (STING) can directly induce IFN-I production. However, elevated IFN-I induces auto-immune phenotypes such as systemic lupus erythematosus (SLE). The effects of AZM and STING on the production of IFN-I are unclear.Objective: Therefore, this study aims to evaluate the role of AZM and STING on IFN-I responses in macrophages.Methods: RAW 264.7 macrophages were treated with AZM with and without a STING-agonist (DMXAA), and the maturation of macrophages was determined using flow cytometry. Gene expression and pro-inflammatory cytokines were analyzed using qPCR and ELISA, respectively. Moreover, protein expression was investigated using Western blot assays and immunofluorescence.Results: Our results show that AZM significantly induced M1 phenotypes, promoting surface molecule expansion of CD80 and MHC-II and production of IL-6 and TNF-α cytokines on DMXAA-stimulated macrophages. Furthermore, we found that AZM-increased mRNA levels of interferon-stimulated genes (ISGs) could be due to the high expression of STNG-TBK1 signaling in the presence of DMXAA.Conclusion: Our data suggest that AZM enhancement of IFN-I responses was STING dependent in DMXAA-stimulated macrophages. These data underline a novel approach to AZM action-mediated STING-TBK1 signaling for regulating IFN-I responses and may further augment the scientific basis and potential use of AZM in clinical applications.Keywords: azithromycin, stimulator of interferon genes, TANK binding kinase 1, type-I interferon
