Induction of IL-25 Expression in Human Nasal Polyp Epithelium by Influenza Virus Infection is Abated by Interferon-Alpha Pretreatment

Haiyu Hong,1– 3,* Kai Sen Tan,3– 6,* Yan Yan,3,7,8,* Fenghong Chen,2,* Hsiao Hui Ong,3,5 Yukei Oo,4 Jing Liu,3,5 Yew Kwang Ong,3,9 Mark Thong,3,9 Richard Sugrue,10 Vincent T Chow,4,5 De Yun Wang3,5 1Allergy Center, Department of Otolaryngology, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, People’s Republic of China; 2Otorhinolaryngology Hospital, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, People’s Republic of China; 3Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore; 4Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore; 5NUHS Infectious Diseases Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 6Biosafety level 3 Core Facility, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore; 7Guangdong Provincial Key Laboratory of Biomedical and Guangdong Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, People’s Republic of China; 8Central Laboratory, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, People’s Republic of China; 9Department of Otolaryngology Head & Neck Surgery, National University Hospital, National University Health System, Singapore; 10School of Biological Sciences, Nanyang Technological University, Singapore*These authors contributed equally to this workCorrespondence: Vincent T ChowDepartment of Microbiology and Immunology, National University of Singapore, 5 Science Drive 2, Singapore, 117545, SingaporeEmail micctk@nus.edu.sgDe Yun WangDepartment of Otolaryngology, National University of Singapore, National University Health System, 1E Kent Ridge Road, Singapore, 119228, SingaporeEmail entwdy@nus.edu.sgBackground: Epithelial cytokines including IL-25, IL-33 and thymic stromal lymphopoietin (TLSP) are recently established as drivers of type 2 chronic inflammatory diseases such as chronic rhinosinusitis with nasal polyps (CRSwNP). Here, we further confirmed the increased expression of IL-25 in CRSwNP and investigated potential contributors of IL-25 in CRSwNP epithelium.Methods: Sixty CRSwNP, 25 CRSsNP and 15 healthy control tissues were examined for IL-25 expression and for the accompanying type 2 inflammatory cytokines. We then tested different respiratory virus infections on human nasal epithelial cells (hNECs) for their ability to trigger IL-25 expression. In addition, we subjected hNECs generated from CRSwNP tissues to pretreatment with recombinant interferon-alpha (IFN-α) prior to viral infection to evaluate IFN effects on IL-25 induction.Results: We confirmed that significantly enhanced levels of IL-25 were observed in CRSwNP tissues, and that IL-25 expression correlated with type 2 inflammatory cytokine expression. In vitro, we observed significantly elevated IL-25 in hNECs infected with influenza A virus as early as 24 hours post-infection (hpi), regardless of tissue origin, and IL-25 correlated positively with viral load. While other respiratory viruses exhibited increasing trends of IL-25, these were not significant at the time-points tested. IFN-α treatment of CRSwNP epithelium was found to exert bimodal effects, ie IFN-α treatment alone induced moderate IL-25 expression, whereas IFN-α pretreatment of hNECs before influenza infection significantly diminished IL-25 induction by active influenza virus infection.Conclusion: We have authenticated the observation of elevated IL-25 in CRSwNP, which is correlated with type 2 inflammatory cytokines. Notably, we identified influenza virus infection as a potential contributor of IL-25 in both control and CRSwNP epithelium during active infection. This IL-25 induction can be abated by IFN-α pretreatment which ameliorated active influenza infection.Trial Registration: Chictr.org.cn ChiCTR-BON-16010179, Registered 18 December 2016, http://www.chictr.org.cn/showproj.aspx?proj=17331. The authors agree on the sharing of deidentified participant data where it pertains to request directly related to the data in this article when contacted (Haiyu Hong; honghy@mail.sysu.edu.cn).Keywords: chronic rhinosinusitis with nasal polyps, interferon-alpha, interleukin 25, respiratory viruses, influenza virus, type 2 inflammation