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Liu Y, Xu L, Lu B, Zhao M, Li L, Sun W, Qiu Z, Zhang B. LncRNA H19/microRNA-675/PPARα axis regulates liver cell injury and energy metabolism remodelling induced by hepatitis B X protein via Akt/mTOR signalling. Mol Immunol 2019; 116:18-28. [PMID: 31574452 DOI: 10.1016/j.molimm.2019.09.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 08/28/2019] [Accepted: 09/04/2019] [Indexed: 12/11/2022]
Abstract
Emerging evidence indicates that the lncRNAs/microRNA/mRNA axis plays important roles in a variety of diseases. This study was aimed to investigate the potential roles and underlying molecular mechanisms of lncRNA H19 and H19-derived miR-675 in regulating hepatitis B virus (HBV)-associated liver injury. mRNA and miR-675 levels were determined by quantitative real-time PCR (qRT-PCR), protein levels were determined by western blot, cell viability was measured by the MTT assay, cell apoptosis was measured by flow cytometry, inflammatory cytokine production was determined by ELISA, oxidative stress and energy metabolism were assessed by commercial kits, and the target relationship between PPARα and miR-675 was confirmed by the dual-luciferase reporter assay. The results showed that the expression of lncRNA H19 and miR-675 was up-regulated in patients with chronic hepatitis B (n = 20). Inhibition of lncRNA H19 or miR-675 in L02 cells increased cell viability, suppressed hepatitis B X protein (HBx)-induced cell apoptosis, inflammatory cytokine production, and oxidative stress, and remodelled energy metabolism. Furthermore, PPARα was found to be a target gene of miR-675. The expression of PPARα was down-regulated in patients with chronic hepatitis B, and there was a negative correlation between the expression of lncRNA H19 and PPARα, or between miR-675 and PPARα. Moreover, by knocking down the expression of PPARα, the actions (apoptosis, inflammatory factors, oxidative stress, and energy metabolism) of lncRNA H19 or miR-675 inhibition in HBx-induced L02 cells were at least partially reversed. In addition, HBx-induced elevated levels of p-AktSer473, p-AktThr308 and p-mTORSer2448 were down-regulated by lncRNA H19 or miR-675 inhibition. Furthermore, PPARα knockdown partly reversed the down-regulated effects of H19 or miR-675 inhibition. Taken together, these data indicate that the lncRNA H19/miR-675/PPARα axis regulates liver cell injury and energy metabolism remodelling induced by HBx, which may be related to the modulation of Akt/mTOR signalling.
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Affiliation(s)
- Yiqing Liu
- Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, 250021, Shandong, China
| | - Li Xu
- Department of Infection/Hepatology, The Second hospital of Shandong University, Jinan 250033, Shandong, China
| | - Bingru Lu
- Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, 250021, Shandong, China
| | - Miaoqing Zhao
- Department of Pathology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, Shandong, China
| | - Li Li
- Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, 250021, Shandong, China
| | - Wenping Sun
- Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, 250021, Shandong, China
| | - Zhanjun Qiu
- Department of Emergency and Critical Care Medicine, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan 250011, Shandong, China.
| | - Bingchang Zhang
- Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, 250021, Shandong, China.
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Chauhan N, Khatri V, Banerjee P, Kalyanasundaram R. Evaluating the Vaccine Potential of a Tetravalent Fusion Protein ( rBmHAXT) Vaccine Antigen Against Lymphatic Filariasis in a Mouse Model. Front Immunol 2018; 9:1520. [PMID: 30013570 PMCID: PMC6036175 DOI: 10.3389/fimmu.2018.01520] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 06/19/2018] [Indexed: 12/22/2022] Open
Abstract
Lymphatic filariasis (LF) is a tropical parasitic infection of human transmitted by mosquitoes. Chronic infection results in severe physical disability in the infected patients. Although several potential vaccine antigens were identified by several groups, there are no licensed prophylactic vaccine to date against this infection in the human. Previous attempts from our laboratory to develop a trivalent prophylactic vaccine against LF showed that >90% protection could be achieved in rodent models. However, this trivalent vaccine gave only 35% protection in non-human primates. The major focus of this study was to develop a tetravalent prophylactic vaccine (rBmHAXT) and test the vaccine potential in a mouse model. We evaluated three different adjuvant formulations; alum, glucopyranosyl lipid adjuvant in stable emulsion (GLA/SE) alum (AL019), and mannosylated chitosan (MCA) to determine the optimum adjuvant formulation for rBmHAXT. Results presented in this study show that rBmHAXT + AL019 gave the highest rate of protection (>88%) against challenge infection, compared to rBmHAXT + AL007 (79%), rBmHAXT + MCA (79%) and controls. Analysis of the immune correlates of protection showed that all three adjuvants elicited high titer of antigen-specific IgG1, IgG2a, and IgG2b antibodies. High number of IFN-γ-producing antigen-specific memory cells were generated in the vaccinated animals irrespective of the adjuvants used. Similarly, spleen cells from rBmHAXT-vaccinated animals secreted IL-4, IL-10, and IFN-γ in response to rBmHAXT suggesting the generation of a balanced Th1/Th2 response. There was also an increase in IL-17-secreting cells in rBmHAXT-vaccinated animals. These findings thus suggest that rBmHAXT + AL019 is a better prophylactic formulation for LF.
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Affiliation(s)
- Nikhil Chauhan
- Department of Biomedical Sciences, University of Illinois, Rockford, IL, United States
| | - Vishal Khatri
- Department of Biomedical Sciences, University of Illinois, Rockford, IL, United States
| | - Priyankana Banerjee
- Department of Biomedical Sciences, University of Illinois, Rockford, IL, United States
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Fu X, Ding Z, Fan J, Wang H, Zhou F, Cui L, Boxiang C, Wang W, Liu H. Characterization, promoter analysis and expression of the interleukin-6 gene in blunt snout bream, Megalobrama amblycephala. FISH PHYSIOLOGY AND BIOCHEMISTRY 2016; 42:1527-1540. [PMID: 27236548 DOI: 10.1007/s10695-016-0238-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 05/14/2015] [Indexed: 06/05/2023]
Abstract
Interleukin-6 (IL-6) is one of the most important multifunctional cytokines, playing essential roles in mediating the innate and adaptive immune responses. In this study, il-6 gene and its promoter from blunt snout bream, Megalobrama amblycephala, were characterized, and its expression at the transcript level in healthy fish and after bacterial infection was determined by quantitative real-time PCR. The results showed that the M. amblycephala il-6 (Mamil-6) cDNA had an ORF of 699 bp, encoding 232 amino acids, and contained 9 instable motifs in the 3' UTR. The deduced MamIL-6 possessed a 24-amino acid signal peptide and was located in the cytoplasm. Although sequence alignment and phylogenetic analysis revealed that IL-6 is poorly conserved in vertebrates, the protein and genomic structure of il-6 gene was well conserved. Analysis of the Mamil-6 promoter revealed the presence of a conserved TATA box and six major cis-regulatory elements, including C/EBPβ (NF-IL6), AP-1, CRE, GRE, GATA and NF-κB binding sites. In healthy fish, Mamil-6 was the most abundant in the spleen. After Aeromonas hydrophila infection, Mamil-6 was significantly up-regulated in all 6 immune-related tissues examined, suggesting that Mamil-6 plays an important role in the blunt snout bream immune system.
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Affiliation(s)
- Xiaoqin Fu
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
- Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China
| | - Zhujin Ding
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
- Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China
| | - Jun Fan
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
- Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China
| | - Huanling Wang
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
- Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China
| | - Fengjuan Zhou
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
- Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China
| | - Lei Cui
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
- Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China
| | - Chen Boxiang
- Animal Husbandry and Fisheries Research Center of Haid Group Co., Ltd, Guangzhou, 511400, China
| | - Weimin Wang
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hong Liu
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.
- Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China.
- College of Life Sciences, Hunan University of Arts and Science, Changde, 415006, Hunan, China.
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Shiou SR, Yu Y, Guo Y, Westerhoff M, Lu L, Petrof EO, Sun J, Claud EC. Oral administration of transforming growth factor-β1 (TGF-β1) protects the immature gut from injury via Smad protein-dependent suppression of epithelial nuclear factor κB (NF-κB) signaling and proinflammatory cytokine production. J Biol Chem 2013; 288:34757-66. [PMID: 24129565 DOI: 10.1074/jbc.m113.503946] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Inflammatory immune responses play an important role in mucosal homeostasis and gut diseases. Nuclear factor κB (NF-κB), central to the proinflammatory cascade, is activated in necrotizing enterocolitis (NEC), a devastating condition of intestinal injury with extensive inflammation in premature infants. TGF-β is a strong immune suppressor and a factor in breast milk, which has been shown to be protective against NEC. In an NEC animal model, oral administration of the isoform TGF-β1 activated the downstream effector Smad2 in intestine and significantly reduced NEC incidence. In addition, TGF-β1 suppressed NF-κB activation, maintained levels of the NF-κB inhibitor IκBα in the intestinal epithelium, and systemically decreased serum levels of IL-6 and IFN-γ. The immature human fetal intestinal epithelial cell line H4 was used as a reductionistic model of the immature enterocyte to investigate mechanism. TGF-β1 pretreatment inhibited the TNF-α-induced IκBα phosphorylation that targets the IκBα protein for degradation and inhibited NF-κB activation. Chromatin immunoprecipitation (ChIP) assays demonstrated decreased NF-κB binding to the promoters of IL-6, IL-8, and IκBα in response to TNF-α with TGF-β1 pretreatment. These TGF-β1 effects appear to be mediated through the canonical Smad pathway as silencing of the TGF-β central mediator Smad4 resulted in loss of the TGF-β1 effects. Thus, TGF-β1 is capable of eliciting anti-inflammatory effects by inhibiting NF-κB specifically in the intestinal epithelium as well as by decreasing systemic IL-6 and IFN-γ levels. Oral administration of TGF-β1 therefore can potentially be used to protect against gastrointestinal diseases.
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Affiliation(s)
- Sheng-Ru Shiou
- From the Department of Pediatrics, Section of Neonatology, and
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Wang J, Cai Y, Ji H, Feng J, Ayana DA, Niu J, Jiang Y. Serum IL-33 levels are associated with liver damage in patients with chronic hepatitis B. J Interferon Cytokine Res 2012; 32:248-53. [PMID: 22304300 DOI: 10.1089/jir.2011.0109] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
This aim of this study was to assess the potential role of IL-33 in the pathogenic process of chronic hepatitis B (CHB). The levels of serum IL-33 and soluble ST2 (sST2) in CHB patients and healthy controls (HC) were determined using enzyme-linked-immunosorbent serologic assay, and the Th1 (IFN-γ, TNF-α, IL-2) and Th2 (IL-4, IL-6, IL-10) cytokines by cytometric bead array. It was found that the levels of serum IL-33 in CHB patients were significantly higher than that of HC at the base line, but decreased after treatment with adefovir dipivoxil for 12 weeks. The levels of serum sST2, as a decoy receptor of IL-33, were significantly higher in CHB patients than the HC. There was no correlation between the levels of serum sST2 and IL-33. The concentrations of serum Th1 (IFN-γ, IL-2) and Th2 (IL-6, IL-10) cytokines in CHB patients significantly increased after treatment compared to the baseline. These results suggest that IL-33 is involved in the pathogenesis of CHB and that adefovir dipivoxil therapy can attenuate the production of IL-33 in patients with CHB.
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Affiliation(s)
- Juan Wang
- Department of Central Laboratory, the Second Part of First Hospital, Jilin University, Changchun, China
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Wang J, Zhao P, Guo H, Sun X, Jiang Z, Xu L, Feng J, Niu J, Jiang Y. Serum IL-33 levels are associated with liver damage in patients with chronic hepatitis C. Mediators Inflamm 2012; 2012:819636. [PMID: 22315510 PMCID: PMC3270460 DOI: 10.1155/2012/819636] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 10/18/2011] [Accepted: 10/19/2011] [Indexed: 12/31/2022] Open
Abstract
Interleukin-33 (IL-33) is associated with the development of Th2 responses. This study examined the potential role of IL-33 in the pathogenic process of chronic hepatitis C (CHC) in Chinese patients. The levels of serum IL-33 and sST2 in 154 patients with CHC, 24 with spontaneously resolved HCV (SR-HCV) infection and 20 healthy controls (HC), were analyzed by ELISA. The concentrations of serum IL-2, IFN-γ, TNF-α, IL-4, IL-6, and IL-10, HCV loads, ALT, AST, and HCV-Ab were measured. We found that the levels of serum IL-33 in CHC patients were significantly higher than those of SR-HCV and HC but decreased after treatment with interferon for 12 weeks. More importantly, the levels of serum IL-33 were correlated with the concentrations of ALT and AST in CHC patients. The levels of serum sST2, as a decoy receptor of IL-33, were significantly higher in CHC and SR-CHC patients than those in HC, and there was no correlation between the levels of serum sST2 and IL-33. The concentrations of serum IFN-γ and IL-6 in CHC patients were significantly lower than those of SR-HCV. These data suggest that IL-33 may be a pathogenic factor contributing to CHC-related liver injury.
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Affiliation(s)
- Juan Wang
- Department of Central Laboratory, The Second Part of First Hospital, Jilin University, Changchun 130032, China
| | - Pingwei Zhao
- Department of Central Laboratory, The Second Part of First Hospital, Jilin University, Changchun 130032, China
| | - Hui Guo
- Department of Central Laboratory, The Second Part of First Hospital, Jilin University, Changchun 130032, China
| | - Xiguang Sun
- Department of Central Laboratory, The Second Part of First Hospital, Jilin University, Changchun 130032, China
| | - Zhenyu Jiang
- Department of Central Laboratory, The Second Part of First Hospital, Jilin University, Changchun 130032, China
| | - Lijun Xu
- Department of Central Laboratory, The Second Part of First Hospital, Jilin University, Changchun 130032, China
| | - Junyan Feng
- Department of Central Laboratory, The Second Part of First Hospital, Jilin University, Changchun 130032, China
| | - Junqi Niu
- Department of Hepatology, First Hospital, Jilin University, Changchun 130032, China
- *Junqi Niu: and
| | - Yanfang Jiang
- Department of Central Laboratory, The Second Part of First Hospital, Jilin University, Changchun 130032, China
- *Yanfang Jiang:
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Gosslau A, En Jao DL, Huang MT, Ho CT, Evans D, Rawson NE, Chen KY. Effects of the black tea polyphenol theaflavin-2 on apoptotic and inflammatory pathways in vitro and in vivo. Mol Nutr Food Res 2011; 55:198-208. [PMID: 20669245 DOI: 10.1002/mnfr.201000165] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
SCOPE Theaflavin-2 (TF-2), a major component of black tea extract, induces apoptosis of human colon cancer cells and suppresses serum-induced cyclooxygenase-2 (COX-2) expression 1. Here, we explored the mechanisms for activation of apoptosis, evaluated the impact on inflammatory genes in a broader panel of cells and tested whether topical anti-inflammatory effects could be observed in vivo. METHODS AND RESULTS TF-2 triggered apoptosis in five other transformed cancer cell lines, inducing cell shrinkage, membrane blebbing, and mitochondrial clustering within 3 h of treatment. Among a set of pro-apoptotic genes, TF-2 quickly induced the up-regulation of P53 and BAX, suggesting mitochondria as the primary target. Using a cell model for inflammatory response, we showed that TF-2 suppressed the 12-O-tetradecanoylphorbol-13-acetate-induced COX-2 gene expression, and also down-regulated TNF-α, iNOS, ICAM-1, and NFκB. A reporter gene assay showed that TF-2 down-regulated COX-2 at the transcriptional level. We also demonstrated that TF-2 exhibited anti-inflammatory activity in two mouse models of inflammation. Topical application with TF-2 significantly reduced ear edema and produced a pattern of gene down-regulation similar to that observed in the cell model. CONCLUSION These results suggest that the anti-inflammatory and pro-apoptotic activity of TF-2 may be exploited therapeutically in cancer and other diseases associated with inflammation.
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Affiliation(s)
- Alexander Gosslau
- WellGen Inc., Commercialization Center for Innovative Technologies, North Brunswick, NJ 08854-8087, USA.
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Liu CJ, Huang YJ, Chen HL, Lin HT, Lin HL, Kuo ML, Huang JL, Chen DS, Chen PJ, Wu HL. Characterization of interleukin 8 in woodchucks with chronic hepatitis B and hepatocellular carcinoma. Genes Immun 2008; 10:27-36. [PMID: 18971938 DOI: 10.1038/gene.2008.86] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The eastern woodchuck, Marmota monax, represents a useful animal model to study hepatitis B virus infection in humans. However, immunological studies in this model have been impeded by a lack of basic information about the components of the immune system such as cytokines and chemokines. To clarify the role(s) of interleukin 8 (IL-8) in chronic hepatitis B and hepatocellular carcinoma (HCC) in the woodchuck model, we cloned and characterized the woodchuck IL-8 cDNA and genomic DNA. Sequence analysis revealed that the organization of the wk-IL-8 gene is similar to that of the human IL-8 gene and consists of four exons and three introns. Woodchuck IL-8 protein exhibits the conserved ELRCXC motif of IL-8 and shows 87, 82, 82 and 79% similarity with rabbit, ovine, bovine and human IL-8 proteins, respectively. The biological activity of wk-IL-8 was demonstrated using neutrophil chemotaxis assays. Wk-IL-8 could be readily detected in both tumor and non-tumor tissues with higher expression in the non-tumor tissues in most cases. The results from this study will facilitate the investigation of IL-8 in the immunopathogenesis of hepadnavirus-related diseases by the woodchuck model.
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Affiliation(s)
- C-J Liu
- Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan
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Castellana B, Iliev DB, Sepulcre MP, MacKenzie S, Goetz FW, Mulero V, Planas JV. Molecular characterization of interleukin-6 in the gilthead seabream (Sparus aurata). Mol Immunol 2008; 45:3363-70. [DOI: 10.1016/j.molimm.2008.04.012] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 04/11/2008] [Accepted: 04/20/2008] [Indexed: 01/30/2023]
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Qiao H, Andrade MV, Lisboa FA, Morgan K, Beaven MA. FcepsilonR1 and toll-like receptors mediate synergistic signals to markedly augment production of inflammatory cytokines in murine mast cells. Blood 2005; 107:610-8. [PMID: 16174756 PMCID: PMC1895616 DOI: 10.1182/blood-2005-06-2271] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Mast cells mediate both IgE-dependent allergic reactions and protective responses against acute infections, possibly through the activation of Toll-like receptors (TLRs). We find that antigen interacts synergistically with TLR2 and TLR4 ligands to markedly enhance production of cytokines in murine mast cell lines. However, the TLR ligands neither stimulated degranulation and release of arachidonic acid nor influenced such responses to antigen, probably because these ligands failed to generate a necessary calcium signal. The enhanced cytokine production could be attributed to synergistic activation of mitogen-activated protein kinases in addition to the engagement of a more effective repertoire of transcription factors for cytokine gene transcription. The synergistic interactions of TLR ligands and antigen might have relevance to the exacerbation of IgE-mediated allergic diseases by infectious agents.
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Affiliation(s)
- Huihong Qiao
- Laboratory of Molecular Immunology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1760, USA
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