Virus Research 197 (2015) 92–100 Contents lists available at ScienceDirect Virus Research j ourna l ho me pa g e: www.elsevier.com/locate/virusres NF-B is required for dengue virus NS5-induced RANTES expression Sasiprapa Khunchai a,b,1 , Mutita Junking a , Aroonroong Suttitheptumrong a , Suwattanee Kooptiwut c , Guy Haegeman a , Thawornchai Limjindaporn d,∗ , Pa-thai Yenchitsomanus a,∗ a Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Thailand b Graduate Program in Immunology, Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Thailand c Department of Physiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Thailand d Department of Anatomy, Faculty of Medicine Siriraj Hospital, Mahidol University, Thailand a r t i c l e i n f o Article history: Received 22 August 2014 Received in revised form 4 December 2014 Accepted 5 December 2014 Available online 16 December 2014 Keywords: Dengue virus NS5 RANTES NF-B a b s t r a c t Dengue virus (DENV) infection associates with renal disorders. Patients with dengue hemorrhagic fever and acute kidney injury have a high mortality rate. Increased levels of cytokines may contribute to the pathogenesis of DENV-induced kidney injury. Currently, molecular mechanisms how DENV induces kid- ney cell injury has not been thoroughly investigated. Excessive cytokine production may be involved in this process. Using human cytokine RT 2 Profiler PCR array, 14 genes including IP-10, RANTES, IL-8, CXCL- 9 and MIP-1 were up-regulated more than 2folds in DENV-infected HEK 293 cells compared to that of mock-infected HEK 293 cells. In the present study, RANTES was suppressed by the NF-B inhibitor, compound A (CpdA), in DENV-infected HEK 293 cells implying the role of NF-B in RANTES expression. Chromatin immunoprecipitation (ChIP) assay showed that NF-B binds more efficiently to its binding sites on the RANTES promoter in NS5-transfected HEK 293 cells than in HEK 293 cells expressing the vector lacking NS5 gene. To further examine whether the NS5-activated RANTES promoter is mediated through NF-B, the two NF-B binding sites on the RANTES promoter were mutated and this promoter was coupled to the luciferase cDNA. The result showed that when both binding sites of NF-B in the RANTES promoter were mutated, the ability of NS5 to induce the luciferase activity was significantly decreased. Therefore, DENV NS5 activates RANTES production by increasing NF-B binding to its binding sites on the RANTES promoter. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) have become an important mosquito-borne human disease worldwide. DHF/DSS are caused by the bites of Aedes mosquitoes carrying dengue virus (DENV), which is a member of the Fla- vivirus genus in the Flaviviridae family. DENV consists of 4 distinct serotypes, which are related, but are different in their antigenic properties. The genome of DENV is a positive stranded RNA with 11 kb in length, encompassing the sequences encoding structural proteins, including capsid (C), membrane protein (M), and enve- lope (E), and non-structural proteins (NS), including NS1, NS2A, ∗ Corresponding authors. Tel.: +66 2 4192777; fax: +66 2 4110169. E-mail addresses: thawornchai.lim@mahidol.ac.th (T. Limjindaporn), ptyench@gmail.com (P.-t. Yenchitsomanus). 1 Present address: Department of Anatomy, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand. NS2B, NS3, NS4A, NS4B, and NS5. DENV infection causes a spec- trum of illnesses ranging from acute febrile episode, known as dengue fever (DF), to the life-threatening DHF, which can occur in both primary and secondary infections, but is usually found in secondary infection, especially with different serotypes from the primary infection. DHF consists of serious complications, such as plasma leakage, hemorrhage, and multiple organ failure, and may lead to hypovolemic shock, known as DSS (Gubler, 1998; Halstead, 1988; Halstead, 2007). DENV infection associates with a variety of renal disorders (Lizarraga and Nayer, 2014). Patients with DHF and acute kid- ney injury have a high mortality rate (Laoprasopwattana et al., 2010; Lee et al., 2009; Mehra et al., 2012). DENV-associated glomerulonephritis with mesangial proliferation and immune complex deposition was reported both in DENV-infected patients (Boonpucknavig et al., 1981) and in a mouse model of DENV infec- tion (Barreto et al., 2004). DENV infects human embryonic kidney 293 (HEK 293) cell line, and 5 IFN-induced cellular proteins were shown to be suppressed by DENV (Jiang et al., 2010). http://dx.doi.org/10.1016/j.virusres.2014.12.007 0168-1702/© 2014 Elsevier B.V. All rights reserved.