Liao, Hsien-HuaHsien-HuaLiaoWang, Yao-ChenYao-ChenWangChen, Miles Chih-MingMiles Chih-MingChenTsai, Hsien-YuHsien-YuTsaiLin, JohnsonJohnsonLinChen, Shui-TeinShui-TeinChenTsay, Gregory JiazerGregory JiazerTsayCheng, Sun-LongSun-LongCheng2012-10-202018-07-062012-10-202018-07-062011http://ntur.lib.ntu.edu.tw//handle/246246/243387Background: Severe Acute Respiratory Syndrome (SARS) is a severe respiratory illness caused by a novel virus, the SARS coronavirus (SARS-CoV). 3C-like protease (3CLpro) of SARS-CoV plays a role in processing viral polypeptide precursors and is responsible of viral maturation. However, the function of 3CLproin host cells remains unknown. This study investigated how the 3CLproaffected the secretion of cytokines in the gene-transfected cells.Results: From immunofluorescence microscopy, the localization of c-myc tagged 3CLprowas detected both in the cytoplasm and nucleus of transfected A549 cells. Expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) was significantly decreased in 3CLpro-transfected cells by both RT-PCR and ELISA, but without changes in other cytokines, i.e., IL-1β, IL-6, IL-8, IL12p40, TNF-α, and TGF-β. Furthermore, the protein levels of NF-kB decreased in 3CLpro-transfected A549 cells when compared to EGFP transfected cells.Conclusions: Our results suggest that the 3CLpromay suppress expression of GM-CSF in transfected A549 cells through down-regulation of NF-kB production. ? 2011 Liao et al; licensee BioMed Central Ltd.en-US[SDGs]SDG3enhanced green fluorescent protein; granulocyte macrophage colony stimulating factor; immunoglobulin enhancer binding protein; interleukin 12p40; interleukin 1beta; interleukin 6; interleukin 8; plasmid enhanced green fluorescent protein c3 vector; plasmid vector; proteinase; transforming growth factor alpha; tumor necrosis factor alpha; unclassified drug; 3C like protease, SARS coronavirus; 3C-like protease, SARS coronavirus; cysteine proteinase; granulocyte macrophage colony stimulating factor; green fluorescent protein; immunoglobulin enhancer binding protein; interleukin 12p40; interleukin 1beta; interleukin 6; interleukin 8; transforming growth factor beta; tumor necrosis factor alpha; virus protein; article; cancer cell culture; cell nucleus; controlled study; cytokine release; cytoplasm; down regulation; enzyme linked immunosorbent assay; gene expression; gene location; genetic transfection; human; human cell; immunofluorescence microscopy; lung carcinoma; oncogene c myc; protein expression; reverse transcription polymerase chain reaction; SARS coronavirus; fluorescence microscopy; genetics; lung tumor; metabolism; mutation; pathology; tumor cell line; Western blotting; Blotting, Western; Cell Line, Tumor; Cysteine Endopeptidases; Down-Regulation; Enzyme-Linked Immunosorbent Assay; Granulocyte-Macrophage Colony-Stimulating Factor; Green Fluorescent Proteins; Humans; Interleukin-12 Subunit p40; Interleukin-1beta; Interleukin-6; Interleukin-8; Lung Neoplasms; Microscopy, Fluorescence; Mutation; NF-kappa B; Reverse Transcriptase Polymerase Chain Reaction; Transfection; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Viral Proteinsjournal article10.1186/1471-2172-12-16http://ntur.lib.ntu.edu.tw/bitstream/246246/243387/-1/82.pdf