Endothelial cell surface expression of protein disulfide isomerase activates β1 and β3 integrins and facilitates dengue virus infection

• Published in: Journal of cellular biochemistry 2012-05, Vol.113 (5), p.1681-1691
• Main Authors: Wan, Shu-Wen, Lin, Chiou-Feng, Lu, Yi-Tien, Lei, Huan-Yao, Anderson, Robert, Lin, Yee-Shin
• Format: Article
• Language: English
• Subjects: Cell Line; Cell Membrane - metabolism; Cell Membrane - virology; Dengue - etiology; Dengue - metabolism; Dengue - virology; Dengue Virus - pathogenicity; Endoplasmic Reticulum - metabolism; Endothelial Cells - drug effects; Endothelial Cells - metabolism; Endothelial Cells - virology; Gene Knockdown Techniques; Golgi Apparatus - metabolism; Humans; Integrin beta1 - metabolism; Integrin beta3 - metabolism; INTEGRINS; Phosphines - pharmacology; PROTEIN DISULFIDE ISOMERASE; Protein Disulfide-Isomerases - antagonists & inhibitors; Protein Disulfide-Isomerases - genetics; Protein Disulfide-Isomerases - metabolism; Receptors, Peptide - antagonists & inhibitors; Receptors, Peptide - genetics; Receptors, Peptide - metabolism; Reducing Agents - pharmacology; RNA, Small Interfering - genetics; Signal Transduction; VIRAL INFECTION; Virus Internalization - drug effects
• ISSN: 0730-2312; 1097-4644
• DOI: 10.1002/jcb.24037

Infection with dengue virus (DENV) causes diseases ranging from mild dengue fever to severe hemorrhage or shock syndrome. DENV infection of endothelial cells may cause cell apoptosis or vascular leakage and result in clinical illness of hemorrhage. However, the endothelial cell molecules involved in DENV infection and the mechanisms governing virus–cell interactions are still uncertain. Since protein disulfide isomerase (PDI) reducing function at the cell surface was shown to be required for entry of certain viruses and bacteria, we explored the role of PDI expressed on endothelial cell surface in DENV infection. Using siRNA to knock down PDI, DENV infection was reduced which could be reversed by treating cells with a reducing agent Tris(2‐carboxyethyl)phosphine hydrochloride (TCEP). DENV‐induced PDI surface expression was mediated through the Lys‐Asp‐Glu‐Leu (KDEL) receptor‐Src family kinase signal pathway. Furthermore, cell surface PDI colocalized with β1 and β3 integrins after DENV infection, and the activation of integrins was blocked by PDI inhibition. Finally, blockade of PDI inhibited DENV entry into endothelial cells. Our findings suggest a novel mechanism whereby surface PDI which causes integrin activation is involved in DENV entry, and DENV infection further increases PDI surface expression at later time points. These findings may have implications for anti‐DENV drug design. J. Cell. Biochem. 113: 1681–1691, 2012. © 2011 Wiley Periodicals, Inc.