title: The complement C1qA enhances retinoic acid-inducible gene-I-mediated immune signalling.
abstract: The cellular innate immune response is essential for recognizing and defending against viral infection. Retinoic acid-inducible gene-I (RIG-I) and virus-induced signaling adaptor (VISA) mediated immune signalling is critically involved in RNA-virus-induced innate immune responses. Here we demonstrate that the complement C1qA interacts with different RIG-I pathway components and enhances RIG-I-VISA-mediated signalling pathway as well as TBK1-mediated activation of interferon-β (IFN-β) promoter. Our data show that over-expression of C1qA up-regulates RIG-I-mediated activation of IFN-stimulated responsive element (ISRE) and nuclear factor-κB reporters and IFN-β transcription, but not IFN regulatory factor-3-mediated and inhibitor of κB kinase-mediated activation of ISRE and nuclear factor-κB promoter. In addition, C1qA can counteract the function of the C1q receptor gC1qR in RIG-I-mediated signalling. Our results reveal the important role of complement C1qA in the innate immune response.
authors.affiliation: Centre for Molecular Immunology, CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Yetao
authors.initials: Y
authors.lastname: Wang
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Tong
authors.forename: Junjie
authors.initials: J
authors.lastname: Zhang
authors.forename: Xin
authors.initials: X
authors.lastname: Ye
mesh_terms: D000818:Animals; D002460:Cell Line; D015922:Complement C1q / Q000276:immunology*; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D004285:Dogs; D006801:Humans; D007113:Immunity, Innate; D016899:Interferon-beta / Q000276:immunology / Q000378:metabolism; D016328:NF-kappa B / Q000276:immunology / Q000378:metabolism; D011971:Receptors, Immunologic; D015398:Signal Transduction
chemical_list: D016328:NF-kappa B; D011971:Receptors, Immunologic; D016899:Interferon-beta; D015922:Complement C1q; C452820:RIGI protein, human; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases