title: An essential role for RIG-I in toll-like receptor-stimulated phagocytosis.
abstract: Retinoic acid-inducible gene-I (RIG-I) plays an important role in antiviral response by recognizing double-stranded RNA. Here we demonstrate an unanticipated role of RIG-I in Toll-like receptor (TLR)-stimulated phagocytosis. Stimulation with lipopolysaccharide (LPS), a ligand of TLR4, induced the expression of RIG-I in macrophages. Depletion of RIG-I by RNAi or gene targeting inhibited the LPS-induced phagocytosis of bacteria. Cellular processes involved in phagocytosis, such as small GTPase Cdc42/Rac1 activation, actin polymerization, and actin-regulator Arp2/3 recruitment, were also impaired in RIG-I-deficient macrophages activated by LPS. Moreover, RIG-I(-/-) mice were found to be more susceptible to infection with Escherichia coli as compared to wild-type mice. Thus, the regulatory functions of RIG-I are strikingly broad, including a role not only in antiviral responses but in antibacterial responses as well.
authors.affiliation: The Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences/Shanghai JiaoTong University School of Medicine, Shanghai 200025, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Kong
authors.forename: Lei
authors.initials: L
authors.lastname: Sun
authors.forename: Hongxin
authors.initials: H
authors.lastname: Zhang
authors.forename: Qin
authors.initials: Q
authors.lastname: Liu
authors.forename: Ye
authors.initials: Y
authors.lastname: Liu
authors.forename: Linhua
authors.initials: L
authors.lastname: Qin
authors.forename: Guojun
authors.initials: G
authors.lastname: Shi
authors.forename: Jun-Hao
authors.initials: JH
authors.lastname: Hu
authors.forename: Ajing
authors.initials: A
authors.lastname: Xu
authors.forename: Yue-Ping
authors.initials: YP
authors.lastname: Sun
authors.forename: Dangsheng
authors.initials: D
authors.lastname: Li
authors.forename: Yu-Fang
authors.initials: YF
authors.lastname: Shi
authors.forename: Jing-Wu
authors.initials: JW
authors.lastname: Zang
authors.forename: Jiang
authors.initials: J
authors.lastname: Zhu
authors.forename: Zhu
authors.initials: Z
authors.lastname: Chen
authors.forename: Zhu-Gang
authors.initials: ZG
authors.lastname: Wang
authors.forename: Bao-Xue
authors.initials: BX
authors.lastname: Ge
mesh_terms: D051376:Actin-Related Protein 2-3 Complex / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000276:immunology*; D004926:Escherichia coli / Q000276:immunology*; D004927:Escherichia coli Infections / Q000276:immunology; D020690:GTPase-Activating Proteins / Q000378:metabolism; D020868:Gene Silencing; D008264:Macrophages / Q000382:microbiology*; D051379:Mice; D018345:Mice, Knockout; D009479:Neuropeptides / Q000378:metabolism; D010587:Phagocytosis / Q000276:immunology*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D016019:Survival Analysis; D051197:Toll-Like Receptor 4 / Q000276:immunology*; D020744:rac GTP-Binding Proteins / Q000378:metabolism; D020830:rac1 GTP-Binding Protein
chemical_list: D051376:Actin-Related Protein 2-3 Complex; C115491:Arhgap31 protein, mouse; D020690:GTPase-Activating Proteins; D009479:Neuropeptides; D034741:RNA, Small Interfering; C484602:Rac1 protein, mouse; D051197:Toll-Like Receptor 4; C503356:Ddx58 protein, mouse; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases; D020744:rac GTP-Binding Proteins; D020830:rac1 GTP-Binding Protein