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Al Hamrashdi M, Brady G. Regulation of IRF3 activation in Human Antiviral Signalling Pathways. Biochem Pharmacol 2022; 200:115026. [PMID: 35367198 DOI: 10.1016/j.bcp.2022.115026] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/24/2022] [Accepted: 03/25/2022] [Indexed: 12/24/2022]
Abstract
The interferon regulatory factor (IRF) family of transcription factors play a vital role in the human innate antiviral immune responses with production of interferons (IFNs) as a hallmark outcome of activation. In recent years, IRF3 has been considered a principal early regulator of type I IFNs (TI-IFNs) directly downstream of intracellular virus sensing. Despite decades of research on IRF-activating pathways, many questions remain on the regulation of IRF3 activation. The kinases IκB kinase epsilon (IKKε) and TANK-binding kinase-1 (TBK1) and the scaffold proteins TRAF family member-associated NF-kappa-B activator (TANK), NF-kappa-B-activating kinase-associated protein 1 (NAP1) and TANK-binding kinase 1-binding protein 1 (TBKBP1)/similar to NAP1 TBK1 adaptor (SINTBAD) are believed to be core components of an IRF3-activation complex yet their contextual involvement and complex composition are still unclear. This review will give an overview of antiviral signaling pathways leading to the activation of IRF3 and discuss recent developments in our understanding of its proximal regulation.
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Affiliation(s)
- Mariya Al Hamrashdi
- Trinity Translational Medicine Institute, Trinity College Dublin, St. James' Hospital Campus, Dublin, Ireland.
| | - Gareth Brady
- Trinity Translational Medicine Institute, Trinity College Dublin, St. James' Hospital Campus, Dublin, Ireland.
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Chen Y, Lin J, Zhao Y, Ma X, Yi H. Toll-like receptor 3 (TLR3) regulation mechanisms and roles in antiviral innate immune responses. J Zhejiang Univ Sci B 2021; 22:609-632. [PMID: 34414698 PMCID: PMC8377577 DOI: 10.1631/jzus.b2000808] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 04/09/2021] [Accepted: 04/09/2021] [Indexed: 01/08/2023]
Abstract
Toll-like receptor 3 (TLR3) is a member of the TLR family, mediating the transcriptional induction of type I interferons (IFNs), proinflammatory cytokines, and chemokines, thereby collectively establishing an antiviral host response. Studies have shown that unlike other TLR family members, TLR3 is the only RNA sensor that is utterly dependent on the Toll-interleukin-1 receptor (TIR)-domain-containing adaptor-inducing IFN-β (TRIF). However, the details of how the TLR3-TRIF signaling pathway works in an antiviral response and how it is regulated are unclear. In this review, we focus on recent advances in understanding the antiviral mechanism of the TRIF pathway and describe the essential characteristics of TLR3 and its antiviral effects. Advancing our understanding of TLR3 may contribute to disease diagnosis and could foster the development of novel treatments for viral diseases.
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Affiliation(s)
- Yujuan Chen
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China
- Chongqing Veterinary Science Engineering Research Center, Chongqing 402460, China
| | - Junhong Lin
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China
- Chongqing Veterinary Science Engineering Research Center, Chongqing 402460, China
| | - Yao Zhao
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China
- Chongqing Veterinary Science Engineering Research Center, Chongqing 402460, China
| | - Xianping Ma
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China
- Chongqing Veterinary Science Engineering Research Center, Chongqing 402460, China
| | - Huashan Yi
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China.
- Chongqing Veterinary Science Engineering Research Center, Chongqing 402460, China.
- Immunology Research Center, Medical Research Institute, Southwest University, Chongqing 402460, China.
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Rajamanickam V, Yan T, Xu S, Hui J, Xu X, Ren L, Liu Z, Liang G, Wang O, Wang Y. Selective targeting of the TLR4 co-receptor, MD2, prevents colon cancer growth and lung metastasis. Int J Biol Sci 2020; 16:1288-1302. [PMID: 32210720 PMCID: PMC7085228 DOI: 10.7150/ijbs.39098] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 02/03/2020] [Indexed: 02/06/2023] Open
Abstract
Toll-like receptor (TLR) signaling is an emerging pathway in tumor cell invasion and metastasis. Myeloid differentiation protein-2 (MD2) contributes to ligand recognition and activation of TLRs in response to exogenous microbial insults or endogenous agents. We hypothesized that blocking MD2 using a specific inhibitor would prevent TLR4-mediated inflammatory responses and metastatic cancer growth. Here, we report that a MD2 inhibitor, L6H21, inhibited migration and invasion of LPS-activated colon cancer CT26.WT cells. These activities were accompanied by inhibition of nuclear factor-κB (NF-κB) activation, and thereby inhibition of the production of pro-inflammatory cytokines and adhesive molecules in colon cancer cells. Furthermore, L6H21 inhibited CT26.WT metastasis to the lung in BALB/c mice as well as suppressed colitis-induced colon cancer induced by azoxymethane/dextran sulfate sodium (AOM/DSS). Taken together, our results demonstrated that L6H21 suppressed tumor invasion and metastasis through blocking TLR4-MD2/NF-κB signaling axis. These findings reveal that inhibition of MD2 may be an important target for the development of colon cancer therapies.
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Affiliation(s)
- Vinothkumar Rajamanickam
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, P. R. China
| | - Tao Yan
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, P. R. China
| | - Shanmei Xu
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, P. R. China
| | - Junguo Hui
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, P. R. China
| | - Xiaohong Xu
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, P. R. China
| | - Luqing Ren
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, P. R. China
| | - Zhoudi Liu
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, P. R. China
| | - Guang Liang
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, P. R. China
| | - Ouchen Wang
- Department of Surgery, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325035, P. R. China
| | - Yi Wang
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, P. R. China
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Metagenomic analysis of the effects of toll-like receptors on bacterial infection in the peritoneal cavity following cecum ligation and puncture in mice. PLoS One 2019; 14:e0220398. [PMID: 31348811 PMCID: PMC6660085 DOI: 10.1371/journal.pone.0220398] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 07/14/2019] [Indexed: 12/12/2022] Open
Abstract
Objective To establish the composition of bacteria in mice following cecum ligation and puncture (CLP) through metagenomic analysis and investigate the role of TLRs on the composition of bacteria. Methods Total DNA extraction was done from the ascites, blood, and fecal samples from C57BL/6 mice sacrificed at 0, 4, 8, and 16 h, as well as from Tlr2–/–, Tlr4–/–, Tlr5–/–, and NF-κB–/–mice sacrificed at 16 h following CLP. Amplification of the V3–V4 regions of the bacterial 16S rRNA genes by PCR and the Illumina MiSeq sequencer was used for deep sequencing. Hierarchical clustering of the isolates was performed with Ward’s method using Euclidean distances. The relative abundance according to operational taxonomic unit (OTU) number or taxa was used to compare the richness among subgroups in the experiments. Results There were 18 taxa that had significantly different abundances among the different samples of the C57BL/6 mice at 16 h following CLP. Various dynamic changes in the infectious bacteria inside the peritoneal cavity after CLP were found. While knockout of Tlr5 and NF-κB impaired the ability of bacterial clearance inside the peritoneal cavity for some kinds of bacteria found in the C57BL/6 mice, the knockout of Tlr4 enhanced clearance for other kinds of bacteria, and they presented excessive abundance in the peritoneal cavity despite their scarce abundance in the stool. Conclusion NF-κB and TLRs are involved in bacterial clearance and in the expression pattern of the bacterial abundance inside the peritoneal cavity during polymicrobial infection.
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