title: The role of C5a in acute lung injury induced by highly pathogenic viral infections.
abstract: The complement system, an important part of innate immunity, plays a critical role in pathogen clearance. Unregulated complement activation is likely to play a crucial role in the pathogenesis of acute lung injury (ALI) induced by highly pathogenic virus including influenza A viruses H5N1, H7N9, and severe acute respiratory syndrome (SARS) coronavirus. In highly pathogenic virus-induced acute lung diseases, high levels of chemotactic and anaphylatoxic C5a were produced as a result of excessive complement activaiton. Overproduced C5a displays powerful biological activities in activation of phagocytic cells, generation of oxidants, and inflammatory sequelae named "cytokine storm", and so on. Blockade of C5a signaling have been implicated in the treatment of ALI induced by highly pathogenic virus. Herein, we review the literature that links C5a and ALI, and review our understanding of the mechanisms by which C5a affects ALI during highly pathogenic viral infection. In particular, we discuss the potential of the blockade of C5a signaling to treat ALI induced by highly pathogenic viruses.
authors.affiliation: Laboratory of Immunology, Institute of Basic Medical Sciences , Beijing 100850, China.
authors.forename: Renxi
authors.initials: R
authors.lastname: Wang
authors.affiliation: Laboratory of Immunology, Institute of Basic Medical Sciences , Beijing 100850, China.
authors.forename: He
authors.initials: H
authors.lastname: Xiao
authors.affiliation: Department of Pathology, University of Michigan , Ann Arbor, Michigan 48109, USA ; InflaRx GmbH , Jena 07745, Germany.
authors.forename: Renfeng
authors.initials: R
authors.lastname: Guo
authors.affiliation: Laboratory of Immunology, Institute of Basic Medical Sciences , Beijing 100850, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Laboratory of Immunology, Institute of Basic Medical Sciences , Beijing 100850, China.
authors.forename: Beifen
authors.initials: B
authors.lastname: Shen
mesh_terms: D055371:Acute Lung Injury / Q000276:immunology* / Q000821:virology; D000818:Animals; D015936:Complement C5a / Q000378:metabolism*; D004195:Disease Models, Animal; D006801:Humans; D017382:Reactive Oxygen Species / Q000378:metabolism; D014777:Virus Diseases / Q000150:complications* / Q000276:immunology; D014780:Viruses / Q000472:pathogenicity*
chemical_list: D017382:Reactive Oxygen Species; D015936:Complement C5a
keywords: C5a; acute lung injury; pro-inflammatory cytokines