Identification of a Novel Regulatory Region Critical for Expression of the RANTES Chemokine in Activated T Lymphocytes
ABSTRACT The RANTES chemokine is a T cell-expressed, proinflammatory cytokine recently implicated as a suppressive agent of HIV replication. We have identified tandem kappaB-like sequences within the promoter for RANTES that are critical for RANTES promoter-reporter gene activity in both the T cell tumor line Hut78 and in PHA-activated PBL. This region binds not only Rel family members (including p50-p65 heterodimers and p50-p50 homodimers) but also non-Rel factors up-regulated in PBL 3 to 5 days following activation. The expression of these "late" expressed nuclear factors correlates with an up-regulation of RANTES message found at this point in T cell activation. These factors are also constitutively expressed in functionally mature CD8+ T cells. We hypothesize that these apparently novel proteins are responsible in part for the temporal regulation of RANTES seen in peripheral blood T cells and represent a component of transcriptional regulatory machinery newly expressed at this "late" stage of peripheral T cell development.
- SourceAvailable from: PubMed Central
[Show abstract] [Hide abstract]
- "The expression of RANTES is differentially regulated in various cell types, and a large number of putative cis-acting elements have been described in the promoter region by Nelson et al. 6, who subsequently also identified a novel regulatory region critical for its expression 30. The RANTES -28C/G polymorphism was found to be adjacent to the NF-кB binding site, which is a potent inducer of RANTES expression 31. "
ABSTRACT: Regulated upon activation, normal T-cell expressed and secreted (RANTES) is one of the most extensively studied C-C chemokines in allergic inflammation. A growing body of evidence suggests that many cell types present in asthmatic airways have the capacity to generate RANTES, which directly supported the potential role of RANTES in asthma. A number of studies have evaluated the functional polymorphism -28C/G in the RANTES promoter region, which had been found to affect the transcription of the RANTES gene, in relation to asthma susceptibility. However, the results remain conflicting rather than conclusive. This meta-analysis on 1894 asthma cases and 1766 controls for -28C/G from 9 published case-control studies showed that the variant allele -28G was associated with significantly increased risk of asthma (GG+CG vs CC: OR=1.24, 95%CI=1.08-1.41) without any between-study heterogeneity. In the stratified analysis by asthma type, age and ethnicity, we found that the increased asthma risk associated with -28G/C polymorphism was more evident in children (OR=1.24, 95%CI=1.06-1.45), Asian group (OR=1.27, 95%CI=1.04-1.56) and African group (OR=1.72, 95%CI=1.07-2.78). These results suggest that RANTES -28G/C polymorphism may contribute to asthma development, especially in children and in Asian population. Additional well-designed large studies were required for the validation of this association.International journal of medical sciences 02/2010; 7(1):55-61. DOI:10.7150/ijms.7.55 · 1.55 Impact Factor
[Show abstract] [Hide abstract]
- "Both DNA fragments were filled in using [␣- 32 P]dCTP (New England Biolabs) and Klenow fragment. Oligonucleotides containing NF-IL6 (nt Ϫ164) and A/B site (nt Ϫ131 to Ϫ103) (Nelson et al., 1996) were annealed and end-labeled with ␥- 32 P-ATP and T4 kinase. Mobility shift electrophoresis assay mixtures contained 0.25 ng of 32 Plabeled DNA fragment or double-stranded oligonucleotides (15,000 cpm), 10 mM HEPES at pH 7.9, 1 mM dithiothreitol, 1 mM EDTA, 0.5 mM MgCl 2 , 5% glycerol, 0.5 g poly(dI-dC), 0.1 g sonicated salmon sperm DNA, and 4 g of nuclear extract. "
ABSTRACT: We had previously reported the cloning of the complete genome of an isolate of hepatitis C virus (HCV), HCV-S1, of genotype 1b. We have constructed a full-length complementary DNA (cDNA) clone of HCV-S1 using nine overlapping cDNA clones that encompassed its entire genome. HCV core, E1, E2, NS-3, -4B, -5A, and -5B proteins were detected in 293T cells by immunoblot analyses when expression of the full-length HCV-S1 was driven under a CMV promoter. Expression of full-length HCV-S1 led to induction of the CC chemokines RANTES and MCP-1 at both the mRNA and the protein levels in HeLa, Huh7, and HepG2 cells. Reporter gene assays showed that a minimal MCP-1 promoter construct containing 128 nucleotides upstream of its translational start site was sufficient for optimal HCV-mediated activation. HCV induced AP-1 binding activities to this region, as determined from electrophoretic mobility shift assays and supershifts with anti-AP-1 antibodies. Transfection of full-length HCV-S1 up-regulated both AP-1 binding activities as well as c-jun transcripts. A minimal promoter construct containing 181 nucleotides upstream of the RANTES translational start site was sufficient for maximal HCV-mediated induction. Gel mobility shift and supershift assays showed that HCV induced NF-kappaB and other unknown binding activities to the A/B-site within this region. In HeLa cells, HCV core and NS5A could separately augment promoter activities of both MCP-1 and RANTES. In Huh7 cells, only NS5A produced a similar effect, while rather surprisingly, HCV core induced a dramatic reduction in promoter activities of these two genes. This study provides the first direct evidence for the induction of CC chemokines in HCV infection and draws attention to their roles in affecting the progress and outcome of HCV-associated liver diseases.Virology 12/2002; 303(2):253-77. DOI:10.1006/viro.2002.1617 · 3.28 Impact Factor
[Show abstract] [Hide abstract]
- "IL-8, MCP-1 and RANTES gene expression are regulated by the redox responsive transcription factor NF-κB [18,20,23,25-33,41-44]. The NF-κB signaling pathways have been shown to be differentially affected by antioxidants and glucocorticoid steroids . "
ABSTRACT: Respiratory syncytial virus (RSV) infection of airway epithelial cells stimulates the expression and secretion of a variety of cytokines including the chemotactic cytokines interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), and RANTES (regulated upon activation, normal T cell expressed and secreted). Chemokines are important chemoattractants for the recruitment of distinct sets of leukocytes to airway sites of inflammation. We have shown previously that chemokine expression is regulated in airway epithelial cells (A549) in a stimulus-specific manner in part through the redox-responsive transcription factors AP-1 and NF-kappaB. In this study, we examined the NF-kappaB-mediated effects of RSV and the proinflammatory cytokine TNFalpha on the induction of IL-8, MCP-1 and RANTES chemokine gene expression in A549 epithelial cells. The results demonstrate that RSV induces chemokine expression with distinct kinetics that is associated with a specific pattern of NF-kappaB binding activity. This distinction was further demonstrated by the differential effects of the NF-kappaB inhibitors dexamethasone (DEX) and N-acetyl-L-cysteine (NAC). NAC preferentially inhibited RSV induced chemokine expression, whereas DEX preferentially inhibited TNFalpha induced chemokine expression. DNA binding studies using NF-kappaB subunit specific binding ELISA demonstrated that RSV and TNFalpha induced different NF-kappaB binding complexes containing Rel A (p65) and NF-kappaB1 (p50). Both TNFalpha and RSV strongly induced Rel A the activation subunit of NF-kappaB, whereas only TNFalpha was able to substantially induce the p50 subunit. Consistent with the expression studies, RSV but not TNFalpha induction of Rel A and p50 were markedly inhibited by NAC, providing a mechanism by which TNFalpha and RSV can differentially activate chemokine gene expression via NF-kappaB. These data suggest that RSV induction of chemokine gene expression, in contrast to TNFalpha, involves redox-sensitive NF-kappaB complexes containing predominantly Rel A.BMC Infectious Diseases 04/2002; 2:5. DOI:10.1186/1471-2334-2-5 · 2.61 Impact Factor