title: IL-9 Inhibits Viral Replication in Coxsackievirus B3-Induced Myocarditis.
abstract: Myocardial injuries in viral myocarditis (VMC) are caused by viral infection and related autoimmune disorders. Recent studies suggest that IL-9 mediated both antimicrobial immune and autoimmune responses in addition to allergic diseases. However, the role of IL-9 in viral infection and VMC remains controversial and uncertain. In this study, we infected Balb/c mice with Coxsackievirus B3 (CVB3), and found that IL-9 was enriched in the blood and hearts of VMC mice on days 5 and 7 after virus infection. Most of IL-9 was secreted by CD8+T cells on day 5 and CD4+T cells on day 7 in the myocardium. Further, IL-9 knockout exacerbated cardiac damage following CVB3 infection, along with a sharp increase in viral replication and IL-17a expression, as well as a decrease in TGF-β. In contrast, the repletion of IL-9 in Balb/c mice with CVB infection induced the opposite effect. Studiesin vitrofurther revealed that IL-9 directly inhibited viral replication in cardiomyocytes by reducing coxsackie and adenovirus receptor expression, which might be associated with upregulation of TGF-β autocrine effect in these cells. However, IL-9 had no direct effect on apoptosis in cardiomyocytes. Our data indicated that IL-9 played a protective role in disease progression by inhibiting CVB3 replication in the early stages of VMC.
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China.
authors.forename: Miao
authors.initials: M
authors.lastname: Yu
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Long
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China.
authors.forename: Huan-Huan
authors.initials: HH
authors.lastname: Li
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liang
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China.
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Liao
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yuan
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Cheng
keywords: IL-9; TGF-β; coxsackie and adenovirus receptor; coxsackievirus B3; viral myocarditis