Effect of 3C-like proteinase on granulocyte-macrophage colony-stimulating factor gene expression in A549 human lung carcinoma cells

• Main Authors: Hsien-Hua, 廖憲華
• Other Authors: Gregory J Tsay
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/50986617874890155148

博士 === 中山醫學大學 === 醫學研究所 === 100 === 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 3CLpro in host cells remains unknown. This study investigated how the 3CLpro affected the secretion of cytokines in the gene-transfected cells. Results From immunofluorescence microscopy, the localization of c-myc tagged 3CLpro was 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 3CLpro may suppress expression of GM-CSF in transfected A549 cells through down-regulation of NF-kB production.