title: Dynamic innate immune responses of human bronchial epithelial cells to severe acute respiratory syndrome-associated coronavirus infection.
abstract: Human lung epithelial cells are likely among the first targets to encounter invading severe acute respiratory syndrome-associated coronavirus (SARS-CoV). Not only can these cells support the growth of SARS-CoV infection, but they are also capable of secreting inflammatory cytokines to initiate and, eventually, aggravate host innate inflammatory responses, causing detrimental immune-mediated pathology within the lungs. Thus, a comprehensive evaluation of the complex epithelial signaling to SARS-CoV is crucial for paving the way to better understand SARS pathogenesis. Based on microarray-based functional genomics, we report here the global gene response of 2B4 cells, a cloned bronchial epithelial cell line derived from Calu-3 cells. Specifically, we found a temporal and spatial activation of nuclear factor (NF)kappaB, activator protein (AP)-1, and interferon regulatory factor (IRF)-3/7 in infected 2B4 cells at 12-, 24-, and 48-hrs post infection (p.i.), resulting in the activation of many antiviral genes, including interferon (IFN)-beta, -lambdas, inflammatory mediators, and many IFN-stimulated genes (ISGs). We also showed, for the first time, that IFN-beta and IFN-lambdas were capable of exerting previously unrecognized, non-redundant, and complementary abilities to limit SARS-CoV replication, even though their expression could not be detected in infected 2B4 bronchial epithelial cells until 48 hrs p.i. Collectively, our results highlight the mechanics of the sequential events of antiviral signaling pathway/s triggered by SARS-CoV in bronchial epithelial cells and identify novel cellular targets for future studies, aiming at advancing strategies against SARS.
authors.affiliation: Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Terence E
authors.initials: TE
authors.lastname: Hill
authors.forename: Naoko
authors.initials: N
authors.lastname: Yoshikawa
authors.forename: Vsevolod L
authors.initials: VL
authors.lastname: Popov
authors.forename: Cristi L
authors.initials: CL
authors.lastname: Galindo
authors.forename: Harold R
authors.initials: HR
authors.lastname: Garner
authors.forename: C J
authors.initials: CJ
authors.lastname: Peters
authors.forename: Chien-Te Kent
authors.initials: CT
authors.lastname: Tseng
mesh_terms: D001980:Bronchi / Q000166:cytology / Q000276:immunology*; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000276:immunology; D015870:Gene Expression; D006801:Humans; D007113:Immunity, Innate; D050838:Interferon Regulatory Factor-3 / Q000378:metabolism; D050839:Interferon Regulatory Factor-7 / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D045473:Severe acute respiratory syndrome-related coronavirus / Q000235:genetics / Q000502:physiology; D045169:Severe Acute Respiratory Syndrome / Q000276:immunology*; D014779:Virus Replication
chemical_list: D050838:Interferon Regulatory Factor-3; D050839:Interferon Regulatory Factor-7; D016328:NF-kappa B