title: Respiratory macrophages and dendritic cells mediate respiratory syncytial virus-induced IL-33 production in TLR3- or TLR7-dependent manner.
abstract: Respiratory syncytial virus (RSV) infection can increase the production of IL-33 in lungs of mice. However, little is known about cellular source of IL-33, particularly the types of IL-33-producing cells in innate immune cells during RSV infection. In this study, by using BALB/c mice that were infected intranasally with RSV, it became clear that RSV infection can enhance not only the number of IL-33(+)-alveolar macrophages (AMs) and dendritic cells (DCs), but also the expression of IL-33 mRNA in these cells, suggesting that innate immune cells participate in the production of IL-33. Indeed, in vitro experiments by using murine cell lines found that RSV infection results in more expression of IL-33 mRNA in AMs and DCs, further confirming that these cell types may be an important source of IL-33 during RSV infection. It should be noted that the expression of mRNA for TLR3 and TLR7 was up-regulated in pulmonary AMs during RSV infection. Blockade of TLRs by TLR3 or TLR7 antagonist significantly reduces the levels of IL-33 mRNA in AMs and DCs, suggesting that RSV-induced IL-33 production might be TLRs-dependent manner. Although the expression of TLRs mRNA in pulmonary interstitial macrophages (IMs) was enhanced after RSV infection, stimulation with agonists or inactivated RSV cannot alter the expression of IL-33 mRNA in IMs, suggesting that pulmonary IMs may not be a source of IL-33 during RSV infection. Thus, these results demonstrate that during RSV infection, respiratory macrophages and dendritic cells mediate the production of IL-33 in a TLR-dependent manner.
authors.affiliation: Department of Immunology, School of Basic Medical Science, China Medical University, Shenyang, China.
authors.forename: Feifei
authors.initials: F
authors.lastname: Qi
authors.affiliation: Department of Immunology, School of Basic Medical Science, China Medical University, Shenyang, China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Immunology, School of Basic Medical Science, China Medical University, Shenyang, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Immunology, School of Basic Medical Science, China Medical University, Shenyang, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Zeng
authors.affiliation: Department of Immunology, School of Basic Medical Science, China Medical University, Shenyang, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Xu
authors.affiliation: Department of Immunology, School of Basic Medical Science, China Medical University, Shenyang, China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Hu
authors.affiliation: Department of Immunology, School of Basic Medical Science, China Medical University, Shenyang, China. Electronic address: bxliu@mail.cmu.edu.cn.
authors.forename: Beixing
authors.initials: B
authors.lastname: Liu
mesh_terms: D000818:Animals; D002460:Cell Line; D016207:Cytokines / Q000096:biosynthesis; D003713:Dendritic Cells / Q000378:metabolism*; D005260:Female; D007113:Immunity, Innate; D000067596:Interleukin-33 / Q000096:biosynthesis*; D008264:Macrophages / Q000378:metabolism; D016676:Macrophages, Alveolar / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D018357:Respiratory Syncytial Virus Infections / Q000378:metabolism*; D018113:Respiratory Syncytial Virus, Human; D051196:Toll-Like Receptor 3 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051199:Toll-Like Receptor 7 / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D016207:Cytokines; C506535:Il33 protein, mouse; D000067596:Interleukin-33; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; C519703:TLR3 protein, mouse; C477038:Tlr7 protein, mouse; D051196:Toll-Like Receptor 3; D051199:Toll-Like Receptor 7
keywords: IL-33; Innate immune cells; Respiratory syncytial virus (RSV); TLRs