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Matziol T, Talagayev V, Slokan T, Strašek Benedik N, Holze J, Sova M, Wolber G, Weindl G. Discovery of Novel Isoxazole-Based Small-Molecule Toll-Like Receptor 8 Antagonists. J Med Chem 2025; 68:4888-4907. [PMID: 39950821 DOI: 10.1021/acs.jmedchem.4c03148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2025]
Abstract
Toll-like receptor 8 (TLR8) recognizes viral and bacterial RNA, initiating inflammatory responses that are crucial for innate immunity. Dysregulated TLR8 signaling contributes to autoimmune diseases, including systemic lupus erythematosus and rheumatoid arthritis, driving chronic inflammation and tissue damage. Therefore, targeting TLR8 has gained attention as a promising therapeutic strategy. We report a novel selective TLR8 antagonist scaffold identified through computational modeling and simulation. In silico-guided rational drug design and synthesis led to potent isoxazole-based compounds that were characterized by structure-activity relationships. The most active compounds inhibited TLR8-mediated signaling in cell lines and primary cells, reduced MyD88 recruitment, suppressed NF-κB- and IRF-dependent signaling, and decreased inflammatory responses. In silico and pharmacological analyses demonstrated competitive binding to the pocket of chemical ligands within the TLR8 dimerization interface. These highly selective and potent TLR8 antagonists possess favorable physicochemical properties, representing potential clinical candidates for TLR8-targeted therapy.
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Affiliation(s)
- Troy Matziol
- Pharmaceutical Institute, Pharmacology and Toxicology Section, University of Bonn, Gerhard-Domagk-Street 3, 53121 Bonn, Germany
| | - Valerij Talagayev
- Institute of Pharmacy, Pharmaceutical and Medicinal ChemistryFreie, Universität Berlin, Königin-Luise-Street 2 + 4, 14195 Berlin, Germany
| | - Tjaša Slokan
- Faculty of Pharmacy, the Department of Pharmaceutical Chemistry, University of Ljubljana, Aškerčeva 7, SI-1000 Ljubljana, Slovenia
| | - Nika Strašek Benedik
- Faculty of Pharmacy, the Department of Pharmaceutical Chemistry, University of Ljubljana, Aškerčeva 7, SI-1000 Ljubljana, Slovenia
| | - Janine Holze
- Pharmaceutical Institute, Pharmacology and Toxicology Section, University of Bonn, Gerhard-Domagk-Street 3, 53121 Bonn, Germany
| | - Matej Sova
- Faculty of Pharmacy, the Department of Pharmaceutical Chemistry, University of Ljubljana, Aškerčeva 7, SI-1000 Ljubljana, Slovenia
| | - Gerhard Wolber
- Institute of Pharmacy, Pharmaceutical and Medicinal ChemistryFreie, Universität Berlin, Königin-Luise-Street 2 + 4, 14195 Berlin, Germany
| | - Günther Weindl
- Pharmaceutical Institute, Pharmacology and Toxicology Section, University of Bonn, Gerhard-Domagk-Street 3, 53121 Bonn, Germany
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2
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Romero AH, Delgado F. 4-Aminoquinoline as a privileged scaffold for the design of leishmanicidal agents: structure-property relationships and key biological targets. Front Chem 2025; 12:1527946. [PMID: 39981131 PMCID: PMC11841433 DOI: 10.3389/fchem.2024.1527946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2024] [Accepted: 12/26/2024] [Indexed: 02/22/2025] Open
Abstract
Leishmaniasis is one of the most important neglected tropical diseases, with more than two million new cases annually. It is endemic in several regions worldwide, representing a public health problem for more than 88 countries, in particular in the tropical and subtropical regions of developing countries. At the moment, there are neither approved vaccines nor effective drugs for the treatment of human leishmaniasis for any of its three typical clinical manifestations, and, importantly, the drugs of clinical use have several side effects, require complex administration regimens, present high cost, and are ineffective in many populations due to pathogen resistance. Moreover, beyond the pharmacological exigencies, there are other challenges concerning its parasitic nature, such as its great genetic plasticity and adaptability, enabling it to activate a battery of genes to develop resistance quickly. All these aspects demand the identification and development of new, safe, and effective chemical systems, which must not only be focused on medicinal chemistry and pharmacological aspects but also consider key aspects relative to parasite survival. In this sense, the quinolines and, in particular, 4-aminoquinoline, represent a privileged scaffold for the design of potential leishmanicidal candidates due not only to their versatility to generate highly active and selective compounds but also to their correlation with well-defined biological targets. These facts make it possible to generate safe leishmanicidal agents targeted at key aspects of parasite survival. The current review summarizes the most current examples of leishmanicidal agents based on 4-aminoquinolines focusing the analysis on two essential aspects: (i) structure-property relationship to identify the key pharmacophores and (ii) mode of action focused on key targets in parasite survival (e.g., depolarization of potential mitochondrial, accumulation into macrophage lysosome, and immunostimulation of host cells). With that information, we seek to give useful guidelines for interested researchers to face the drug discovery and development process for selective and potent leishmanicidal agents based on 4-aminoquinolines.
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Affiliation(s)
- Angel H. Romero
- Grupo de Química Orgánica Medicinal, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
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3
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Holze J, Lauber F, Soler S, Kostenis E, Weindl G. Label-free biosensor assay decodes the dynamics of Toll-like receptor signaling. Nat Commun 2024; 15:9554. [PMID: 39532846 PMCID: PMC11558003 DOI: 10.1038/s41467-024-53770-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 10/22/2024] [Indexed: 11/16/2024] Open
Abstract
The discovery of Toll-like receptors (TLRs) represented a significant breakthrough that paved the way for the study of host-pathogen interactions in innate immunity. However, there are still major gaps in understanding TLR function, especially regarding the early dynamics of downstream TLR pathways. Here, we present a label-free optical biosensor-based assay as a method for detecting TLR activation in a native and label-free environment and defining the dynamics of TLR pathway activation. This technology is sufficiently sensitive to detect TLR signaling and readily discriminates between different TLR signaling pathways. We define pharmacological modulators of cell surface and endosomal TLRs and downstream signaling molecules and uncover TLR signaling signatures, including potential biased receptor signaling. These findings highlight that optical biosensor assays complement traditional assays that use a single endpoint and have the potential to facilitate the future design of selective drugs targeting TLRs and their downstream effector cascades.
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Affiliation(s)
- Janine Holze
- Pharmaceutical Institute, Section Pharmacology and Toxicology, University of Bonn, Bonn, Germany
| | - Felicitas Lauber
- Pharmaceutical Institute, Section Pharmacology and Toxicology, University of Bonn, Bonn, Germany
| | - Sofía Soler
- Institute of Experimental Haematology and Transfusion Medicine, University Hospital Bonn, Bonn, Germany
| | - Evi Kostenis
- Institute for Pharmaceutical Biology, Molecular, Cellular and Pharmacobiology Section, University of Bonn, Bonn, Germany
| | - Günther Weindl
- Pharmaceutical Institute, Section Pharmacology and Toxicology, University of Bonn, Bonn, Germany.
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4
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Wang M, Chen H, Zhang T, Zhang Z, Xiang X, Gao M, Guo Y, Jiang S, Yin K, Chen M, Huang J, Zhong X, Ohto U, Li J, Shimizu T, Yin H. Targeting toll-like receptor 7 as a therapeutic development strategy for systemic lupus erythematosus. Acta Pharm Sin B 2024; 14:4899-4913. [PMID: 39664432 PMCID: PMC11628833 DOI: 10.1016/j.apsb.2024.08.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Revised: 07/05/2024] [Accepted: 08/12/2024] [Indexed: 12/13/2024] Open
Abstract
Endosomal TLRs (TLR3/7/8/9) are highly analogous innate immunity sensors for various viral or bacterial RNA/DNA molecular patterns. Among them, TLR7, in particular, has been suggested to be a target for various inflammatory disorders and autoimmune diseases including systemic lupus erythematosus (SLE); but few small-molecule inhibitors with elaborated mechanism have been reported in literature. Here, we reported a well-characterized human TLR7-specific small-molecule inhibitor, TH-407b, with promising potency and negligible cytotoxicity through a novel binding mechanism. Notably, TH-407b not only effectively inhibited TLR7-mediated pro-inflammatory signaling in a variety of cultured cell lines but also demonstrated potent inflammation suppressing activities in primary peripheral blood mononuclear cells (PBMCs) derived from SLE patients. Furthermore, TH-407b showed prominent efficacy in vivo, improved survival rate and ameliorated symptoms of SLE model mice. To obtain molecular insights into the TH-407b derivatives' inhibition mechanism, we performed the structural analysis of TLR7/TH-407b complex using cryogenic electron microscopy (cryo-EM) method. As an atomistic resolution cryo-EM structure of the TLR family, it not only of value to facilitate structure-based drug design, but also shed light to methodology development of small proteins using EM. Significantly, TH-407b has unveiled an inhibition strategy for TLR7 via stabilizing its resting/inactivated state. Such a resting state could be generally applicable to all TLRs, rendering a useful method for targeting this group of important immunological receptors.
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Affiliation(s)
- Meng Wang
- Toll Biotech Co., Ltd. (Beijing), Beijing 102209, China
| | - Hekai Chen
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua-Peking Center for Life Sciences, Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing 100084, China
| | - Tuan Zhang
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua-Peking Center for Life Sciences, Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing 100084, China
| | - Zhikuan Zhang
- Graduate School of Pharmaceutical Sciences, the University of Tokyo, Tokyo 113-0033, Japan
| | - Xuwen Xiang
- Toll Biotech Co., Ltd. (Beijing), Beijing 102209, China
| | - Meng Gao
- Toll Biotech Co., Ltd. (Beijing), Beijing 102209, China
| | - Yilan Guo
- Toll Biotech Co., Ltd. (Beijing), Beijing 102209, China
| | - Shuangshuang Jiang
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua-Peking Center for Life Sciences, Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing 100084, China
| | - Kejun Yin
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua-Peking Center for Life Sciences, Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing 100084, China
| | - Mintao Chen
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua-Peking Center for Life Sciences, Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing 100084, China
| | - Jian Huang
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua-Peking Center for Life Sciences, Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing 100084, China
| | - Xincheng Zhong
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua-Peking Center for Life Sciences, Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing 100084, China
| | - Umeharu Ohto
- Graduate School of Pharmaceutical Sciences, the University of Tokyo, Tokyo 113-0033, Japan
| | - Jing Li
- Department of Rheumatology and Clinical Immunology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100032, China
| | - Toshiyuki Shimizu
- Graduate School of Pharmaceutical Sciences, the University of Tokyo, Tokyo 113-0033, Japan
| | - Hang Yin
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua-Peking Center for Life Sciences, Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing 100084, China
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5
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Liu T, Yao W, Sun W, Yuan Y, Liu C, Liu X, Wang X, Jiang H. Components, Formulations, Deliveries, and Combinations of Tumor Vaccines. ACS NANO 2024; 18:18801-18833. [PMID: 38979917 DOI: 10.1021/acsnano.4c05065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Tumor vaccines, an important part of immunotherapy, prevent cancer or kill existing tumor cells by activating or restoring the body's own immune system. Currently, various formulations of tumor vaccines have been developed, including cell vaccines, tumor cell membrane vaccines, tumor DNA vaccines, tumor mRNA vaccines, tumor polypeptide vaccines, virus-vectored tumor vaccines, and tumor-in-situ vaccines. There are also multiple delivery systems for tumor vaccines, such as liposomes, cell membrane vesicles, viruses, exosomes, and emulsions. In addition, to decrease the risk of tumor immune escape and immune tolerance that may exist with a single tumor vaccine, combination therapy of tumor vaccines with radiotherapy, chemotherapy, immune checkpoint inhibitors, cytokines, CAR-T therapy, or photoimmunotherapy is an effective strategy. Given the critical role of tumor vaccines in immunotherapy, here, we look back to the history of tumor vaccines, and we discuss the antigens, adjuvants, formulations, delivery systems, mechanisms, combination therapy, and future directions of tumor vaccines.
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Affiliation(s)
- Tengfei Liu
- State Key Laboratory of Digital Medical Engineering, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu 210096, China
| | - Wenyan Yao
- State Key Laboratory of Digital Medical Engineering, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu 210096, China
| | - Wenyu Sun
- State Key Laboratory of Digital Medical Engineering, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu 210096, China
| | - Yihan Yuan
- State Key Laboratory of Digital Medical Engineering, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu 210096, China
| | - Chen Liu
- State Key Laboratory of Digital Medical Engineering, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu 210096, China
| | - Xiaohui Liu
- State Key Laboratory of Digital Medical Engineering, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu 210096, China
| | - Xuemei Wang
- State Key Laboratory of Digital Medical Engineering, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu 210096, China
| | - Hui Jiang
- State Key Laboratory of Digital Medical Engineering, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu 210096, China
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Haseeb M, Choi YS, Patra MC, Jeong U, Lee WH, Qayyum N, Choi H, Kim W, Choi S. Discovery of Novel Small Molecule Dual Inhibitor Targeting Toll-Like Receptors 7 and 9. J Chem Inf Model 2024; 64:5090-5107. [PMID: 38904299 DOI: 10.1021/acs.jcim.4c00578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
The aberrant secretion of proinflammatory cytokines by immune cells is the principal cause of inflammatory diseases, such as systemic lupus erythematosus and rheumatoid arthritis. Toll-like receptor 7 (TLR7) and TLR9, sequestered to the endosomal compartment of dendritic cells and macrophages, are closely associated with the initiation and progression of these diseases. Therefore, the development of drugs targeting dysregulated endosomal TLRs is imperative to mitigate systemic inflammation. Here, we applied the principles of computer-aided drug discovery to identify a novel low-molecular-weight compound, TLR inhibitory compound 10 (TIC10), and its potent derivative (TIC10g), which demonstrated dual inhibition of TLR7 and TLR9 signaling pathways. Compared to TIC10, TIC10g exhibited a more pronounced inhibition of the TLR7- and TLR9-mediated secretion of the proinflammatory cytokine tumor necrosis factor-α in a mouse macrophage cell line and mouse bone marrow dendritic cells in a concentration-dependent manner. While TIC10g slightly prevented TLR3 and TLR8 activation, it had no impact on cell surface TLRs (TLR1/2, TLR2/6, TLR4, or TLR5), indicating its selectivity for TLR7 and TLR9. Additionally, mechanistic studies suggested that TIC10g interfered with TLR9 activation by CpG DNA and suppressed downstream pathways by directly binding to TLR9. Western blot analysis revealed that TIC10g downregulated the phosphorylation of the p65 subunit of nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinases (MAPKs), including extracellular-signal-regulated kinase, p38-MAPK, and c-Jun N-terminal kinase. These findings indicate that the novel ligand, TIC10g, is a specific dual inhibitor of endosomal TLRs (TLR7 and TLR9), disrupting MAPK- and NF-κB-mediated proinflammatory gene expression.
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Affiliation(s)
- Muhammad Haseeb
- S&K Therapeutics, Ajou University, Campus Plaza 418, 199 Worldcup-ro, Yeongtong-gu, Suwon 16502, Korea
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Korea
| | - Yang Seon Choi
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Korea
| | - Mahesh Chandra Patra
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Korea
| | - Uisuk Jeong
- S&K Therapeutics, Ajou University, Campus Plaza 418, 199 Worldcup-ro, Yeongtong-gu, Suwon 16502, Korea
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Korea
| | - Wang Hee Lee
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Korea
| | - Naila Qayyum
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Korea
| | - Hongjoon Choi
- S&K Therapeutics, Ajou University, Campus Plaza 418, 199 Worldcup-ro, Yeongtong-gu, Suwon 16502, Korea
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Korea
| | - Wook Kim
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Korea
| | - Sangdun Choi
- S&K Therapeutics, Ajou University, Campus Plaza 418, 199 Worldcup-ro, Yeongtong-gu, Suwon 16502, Korea
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Korea
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7
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Gaudenzi C, Schioppa T, Passari M, Zucchi G, Tiberio L, Vahidi Y, Scutera S, Musso T, Sozzani S, Del Prete A, Salvi V, Bosisio D. Extracellular microRNAs induce dendritic cell-dependent joint inflammation and potentiate osteoclast differentiation via TLR7/8 engagement. J Autoimmun 2024; 145:103189. [PMID: 38442677 DOI: 10.1016/j.jaut.2024.103189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 01/11/2024] [Accepted: 02/20/2024] [Indexed: 03/07/2024]
Abstract
OBJECTIVES Monocyte-derived dendritic cells (DCs) are key players in the induction of inflammation, autoreactive T cell activation and loss of tolerance in rheumatoid arthritis (RA), but the precise mechanisms underlying their activation remain elusive. Here, we hypothesized that extracellular microRNAs released in RA synovial fluids may represent a novel, physiological stimulus triggering unwanted immune response via TLR8-expressing DC stimulation. METHODS Human monocyte-derived DCs were stimulated with a mixture of GU-rich miRNAs upregulated in RA tissues and released in synovial fluids (Ex-miRNAs). Activation of DCs was assessed in terms of NF-κB activation by Western blot, cytokine production by ELISA, T cell proliferation and polarization by allogeneic mixed lymphocyte reaction. DC differentiation into osteoclasts was evaluated in terms of tartrate-resistant acid phosphatase production and formation of resorption pits in dentine slices. Induction of joint inflammation in vivo was evaluated using a murine model of DC-induced arthritis. TLR7/8 involvement was assessed by specific inhibitors. RESULTS Ex-miRNAs activate DCs to secrete TNFα, induce joint inflammation, start an early autoimmune response and potentiate the differentiation of DCs into aggressive osteoclasts. CONCLUSIONS This work represents a proof of concept that the pool of extracellular miRNAs overexpressed in RA joints can act as a physiological activator of inflammation via the stimulation of TLR8 expressed by human DCs, which in turn exert arthritogenic functions. In this scenario, pharmacological inhibition of TLR8 might offer a new therapeutic option to reduce inflammation and osteoclast-mediated bone destruction in RA.
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Affiliation(s)
- Carolina Gaudenzi
- Department of Molecular and Translational Medicine, University of Brescia, Italy
| | - Tiziana Schioppa
- Department of Molecular and Translational Medicine, University of Brescia, Italy; IRCCS Humanitas Research Hospital, Milan, Italy
| | - Mauro Passari
- Department of Molecular and Translational Medicine, University of Brescia, Italy
| | - Giovanni Zucchi
- Department of Molecular Medicine, Sapienza University of Rome, Laboratory Affiliated to Institute Pasteur-Italia, Rome, Italy
| | - Laura Tiberio
- Department of Molecular and Translational Medicine, University of Brescia, Italy
| | - Yasmin Vahidi
- Department of Molecular and Translational Medicine, University of Brescia, Italy
| | - Sara Scutera
- Department of Public Health and Pediatric Sciences, University of Turin, Italy
| | - Tiziana Musso
- Department of Public Health and Pediatric Sciences, University of Turin, Italy
| | - Silvano Sozzani
- Department of Molecular Medicine, Sapienza University of Rome, Laboratory Affiliated to Institute Pasteur-Italia, Rome, Italy; IRCCS Neuromed, Pozzilli (IS), Italy
| | - Annalisa Del Prete
- Department of Molecular and Translational Medicine, University of Brescia, Italy; IRCCS Humanitas Research Hospital, Milan, Italy
| | - Valentina Salvi
- Department of Molecular and Translational Medicine, University of Brescia, Italy
| | - Daniela Bosisio
- Department of Molecular and Translational Medicine, University of Brescia, Italy.
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Kawai T, Ikegawa M, Ori D, Akira S. Decoding Toll-like receptors: Recent insights and perspectives in innate immunity. Immunity 2024; 57:649-673. [PMID: 38599164 DOI: 10.1016/j.immuni.2024.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 02/18/2024] [Accepted: 03/05/2024] [Indexed: 04/12/2024]
Abstract
Toll-like receptors (TLRs) are an evolutionarily conserved family in the innate immune system and are the first line of host defense against microbial pathogens by recognizing pathogen-associated molecular patterns (PAMPs). TLRs, categorized into cell surface and endosomal subfamilies, recognize diverse PAMPs, and structural elucidation of TLRs and PAMP complexes has revealed their intricate mechanisms. TLRs activate common and specific signaling pathways to shape immune responses. Recent studies have shown the importance of post-transcriptional regulation in TLR-mediated inflammatory responses. Despite their protective functions, aberrant responses of TLRs contribute to inflammatory and autoimmune disorders. Understanding the delicate balance between TLR activation and regulatory mechanisms is crucial for deciphering their dual role in immune defense and disease pathogenesis. This review provides an overview of recent insights into the history of TLR discovery, elucidation of TLR ligands and signaling pathways, and their relevance to various diseases.
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Affiliation(s)
- Taro Kawai
- Laboratory of Molecular Immunobiology, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Nara 630-0192, Japan; Life Science Collaboration Center (LiSCo), Nara Institute of Science and Technology (NAIST), Nara 630-0192, Japan.
| | - Moe Ikegawa
- Laboratory of Molecular Immunobiology, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Nara 630-0192, Japan
| | - Daisuke Ori
- Laboratory of Molecular Immunobiology, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Nara 630-0192, Japan
| | - Shizuo Akira
- Center for Advanced Modalities and DSS (CAMaD), Osaka University, Osaka 565-0871, Japan; Laboratory of Host Defense, Immunology Frontier Research Center (IFReC), Osaka University, Osaka 565-0871, Japan; Department of Host Defense, Research Institute for Microbial Diseases (RIMD), Osaka University, Osaka 565-0871, Japan.
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Sadeghkhani F, Hajihassan Z, Gharaghani S. Identification of new potent agonists for toll-like receptor 8 by virtual screening methods, molecular dynamics simulation, and MM-GBSA. J Biomol Struct Dyn 2023; 41:10026-10036. [PMID: 36469705 DOI: 10.1080/07391102.2022.2152368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 11/22/2022] [Indexed: 12/12/2022]
Abstract
Toll-like receptor 8 (TLR8), as an endosomal transmembrane receptor, plays a crucial role in the innate immune response to neoplasia and viruses. Previous studies have shown that TLR8 agonists e.g. Motolimod can be used to treat patients with last-stage cancer. In this study, in order to find new suitable ligands for TLR8, 16 PBD codes related to TLR8 complexes were collected to design the pharmacophore models using the Pharmit server. Then the PubChem, and ZINC databases were screened by them. Subsequently, the ADME-Tox features of the compounds were detected using FAF-Drugs4 and the selected compounds were docked to TLR8 (PDB: 3w3j). Molecular dynamics simulation was used to compare compounds with the best docking scores, with Motolimod in complex with TLR8. Finally, two compounds were identified, PubChem: 124126919 (A) and PubChem: 18559540 (B), each with advantages over Motolimod. As the RMSD results showed that compound A has very good flexibility, in terms of energy calculated using the MM-GBSA method, complex B and TLR8 showed the lowest energy level compared to the rest of the complexes. These observations suggest that these two compounds could be used as TLR8 agonists with the desired pharmacological features in future experimental studies.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Farideh Sadeghkhani
- Department of Life Science Engineering, Faculty of New Sciences & Technologies, University of Tehran, Tehran, Iran
| | - Zahra Hajihassan
- Department of Life Science Engineering, Faculty of New Sciences & Technologies, University of Tehran, Tehran, Iran
| | - Sajjad Gharaghani
- Laboratory of Bioinformatics and Drug Design, Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
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Mahmoud IS, Jarrar YB, Febrimarsa. Modulation of IRAK enzymes as a therapeutic strategy against SARS-CoV-2 induced cytokine storm. Clin Exp Med 2023; 23:2909-2923. [PMID: 37061574 PMCID: PMC10105542 DOI: 10.1007/s10238-023-01064-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 04/02/2023] [Indexed: 04/17/2023]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the current pandemic coronavirus disease 2019 (COVID-19). Dysregulated and excessive production of cytokines and chemokines, known as cytokine storm, is frequently seen in patients with severe COVID-19 disease and it can provoke a severe systematic inflammation in the patients. The IL-1R/TLRs/IRAKs signaling network is a key pathway in immune cells that plays a central role in regulating innate immunity and inflammatory responses via stimulating the expression and production of various proinflammatory molecules including cytokines. Modulation of IRAKs activity has been proposed to be a promising strategy in the treatment of inflammatory disorders. In this review, we highlight the biochemical properties of IRAKs and their role in regulating inflammatory molecular signaling pathways and discuss the potential targeting of IRAKs to suppress the SARS-CoV-2-induced cytokine storm in COVID-19 patients.
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Affiliation(s)
- Ismail Sami Mahmoud
- Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, The Hashemite University, Zarqa, 13133, Jordan.
| | - Yazun Bashir Jarrar
- Department of Basic Medical Sciences, Faculty of Medicine, Al-Balqa Applied University, As-Salt, Jordan
| | - Febrimarsa
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway, Republic of Ireland
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11
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Verma S, Reddy P, Sowdhamini R. Integrated approaches for the recognition of small molecule inhibitors for Toll-like receptor 4. Comput Struct Biotechnol J 2023; 21:3680-3689. [PMID: 37576745 PMCID: PMC10412839 DOI: 10.1016/j.csbj.2023.07.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 07/08/2023] [Accepted: 07/19/2023] [Indexed: 08/15/2023] Open
Abstract
Toll-like receptors (TLRs) are pattern recognition receptors present on the surface of cells playing a crucial role in innate immunity. One of the TLRs, TLR4, recognizes LPS (Lipopolysaccharide) as its ligand leading to the release of anti-inflammatory mediators as well as pro-inflammatory cytokines through signal transduction and domain recruitment. TLR4 homodimerizes at its intracellular TIR (Toll/interleukin-1 receptor) domain that helps in the recruitment of the TRAM/TICAM2 (TIR domain-containing adaptor molecule 2) molecule. TRAM also contains TIR domain which in turn, dimerizes and functions as an adapter protein to further recruit TRIF/TICAM1 (TIR domain-containing adaptor molecule 1) protein for mediating downstream signaling. Apart from LPS, TLR4 also recognizes endogenous ligands like fibrinogen, HMGB1, and hyaluronan in autoimmune conditions and sepsis. We employed computational approaches to target TRAM and recognize small molecule inhibitors from small molecules of natural origin, as contained in the Super Natural II database. Finally, cell reporter assays and NMR studies enabled the identification of promising lead compounds. Hence, this study aims to attenuate the signaling of the TLR4-TRAM-TRIF cascade in these auto-inflammatory conditions.
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Affiliation(s)
- Shailya Verma
- National Centre for Biological Sciences (TIFR), GKVK campus, Bangalore 560065, India
| | - Purushotham Reddy
- National Centre for Biological Sciences (TIFR), GKVK campus, Bangalore 560065, India
- NMR-Analytical research and development, Aurobindo Pharma, Research center-II, Hyderabad, Telangana 502307, India
| | - R. Sowdhamini
- National Centre for Biological Sciences (TIFR), GKVK campus, Bangalore 560065, India
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
- Institute of Bioinformatics and Applied Biotechnology, Electronic City, 560100, India
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12
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Kim JY, Rosenberger MG, Rutledge NS, Esser-Kahn AP. Next-Generation Adjuvants: Applying Engineering Methods to Create and Evaluate Novel Immunological Responses. Pharmaceutics 2023; 15:1687. [PMID: 37376133 PMCID: PMC10300703 DOI: 10.3390/pharmaceutics15061687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 06/02/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
Adjuvants are a critical component of vaccines. Adjuvants typically target receptors that activate innate immune signaling pathways. Historically, adjuvant development has been laborious and slow, but has begun to accelerate over the past decade. Current adjuvant development consists of screening for an activating molecule, formulating lead molecules with an antigen, and testing this combination in an animal model. There are very few adjuvants approved for use in vaccines, however, as new candidates often fail due to poor clinical efficacy, intolerable side effects, or formulation limitations. Here, we consider new approaches using tools from engineering to improve next-generation adjuvant discovery and development. These approaches will create new immunological outcomes that will be evaluated with novel diagnostic tools. Potential improved immunological outcomes include reduced vaccine reactogenicity, tunable adaptive responses, and enhanced adjuvant delivery. Evaluations of these outcomes can leverage computational approaches to interpret "big data" obtained from experimentation. Applying engineering concepts and solutions will provide alternative perspectives, further accelerating the field of adjuvant discovery.
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Affiliation(s)
| | | | | | - Aaron P. Esser-Kahn
- Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637, USA; (J.Y.K.); (M.G.R.); (N.S.R.)
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13
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Wang J, Zhang J, Wang J, Hu X, Ouyang L, Wang Y. Small-Molecule Modulators Targeting Toll-like Receptors for Potential Anticancer Therapeutics. J Med Chem 2023; 66:6437-6462. [PMID: 37163340 DOI: 10.1021/acs.jmedchem.2c01655] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Toll-like receptors (TLRs) are key components of the innate immune system and serve as a crucial link between innate and acquired immunity. In addition to immune function, TLRs are involved in other important pathological processes, including tumorigenesis. TLRs have dual regulatory effects on tumor immunity by activating nuclear factor κ-B signaling pathways, which induce tumor immune evasion or enhance the antitumor immune response. Therefore, TLRs have become a popular target for cancer prevention and treatment, and TLR agonists and antagonists offer considerable potential for drug development. The TLR7 agonist imiquimod (1) has been approved by the U.S. Food and Drug Administration as a treatment for malignant skin cancer. Herein, the structure, signaling pathways, and function of the TLR family are summarized, and the structure-activity relationships associated with TLR selective and multitarget modulators and their potential application in tumor therapy are systematically discussed.
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Affiliation(s)
- Jiayu Wang
- Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, Joint Research Institution of Altitude Health, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
- College of Life Sciences, Sichuan University, Chengdu 610064, Sichuan, China
| | - Jifa Zhang
- Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, Joint Research Institution of Altitude Health, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
| | - Jiaxing Wang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee 38163, United States
| | - Xinyue Hu
- Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, Joint Research Institution of Altitude Health, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
- College of Life Sciences, Sichuan University, Chengdu 610064, Sichuan, China
| | - Liang Ouyang
- Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, Joint Research Institution of Altitude Health, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
| | - Yuxi Wang
- Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, Joint Research Institution of Altitude Health, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
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14
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The link between rheumatic disorders and inborn errors of immunity. EBioMedicine 2023; 90:104501. [PMID: 36870198 PMCID: PMC9996386 DOI: 10.1016/j.ebiom.2023.104501] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 12/11/2022] [Accepted: 02/10/2023] [Indexed: 03/06/2023] Open
Abstract
Inborn errors of immunity (IEIs) are immunological disorders characterized by variable susceptibility to infections, immune dysregulation and/or malignancies, as a consequence of damaging germline variants in single genes. Though initially identified among patients with unusual, severe or recurrent infections, non-infectious manifestations and especially immune dysregulation in the form of autoimmunity or autoinflammation can be the first or dominant phenotypic aspect of IEIs. An increasing number of IEIs causing autoimmunity or autoinflammation, including rheumatic disease have been reported over the last decade. Despite their rarity, identification of those disorders provided insight into the pathomechanisms of immune dysregulation, which may be relevant for understanding the pathogenesis of systemic rheumatic disorders. In this review, we present novel IEIs primarily causing autoimmunity or autoinflammation along with their pathogenic mechanisms. In addition, we explore the likely pathophysiological and clinical relevance of IEIs in systemic rheumatic disorders.
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15
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O'Reilly S. Toll-like receptor triggering in systemic sclerosis: time to target. Rheumatology (Oxford) 2023; 62:SI12-SI19. [PMID: 35863054 DOI: 10.1093/rheumatology/keac421] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 07/04/2022] [Accepted: 07/08/2022] [Indexed: 02/07/2023] Open
Abstract
SSc is an autoimmune disease that has features of vascular abnormalities, inflammation and skin and lung fibrosis. Toll-like receptors (TLRs) are sentinel receptors that serve to recognize pathogens or internal danger signals leading to downstream signalling pathways that ultimately lead to inflammation and modification of adaptive immunity. Inflammation and fibrosis appear intricately connected in this disease and TLR ligation on fibroblasts can directly activate these cells to produce copious amounts of collagen, a hallmark of disease. The presence of damage-associated molecular patterns in association with fibrosis has been highlighted. Given their prominent role in disease, this review discusses the evidence of their expression and role in disease pathogenesis and possible therapeutic intervention to mitigate fibrosis.
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16
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Targeting toll-like receptors on T cells as a therapeutic strategy against tumors. Int Immunopharmacol 2022; 107:108708. [DOI: 10.1016/j.intimp.2022.108708] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 03/05/2022] [Accepted: 03/13/2022] [Indexed: 12/11/2022]
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17
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Köllisch G, Solis FV, Obermann HL, Eckert J, Müller T, Vierbuchen T, Rickmeyer T, Muche S, Przyborski JM, Heine H, Kaufmann A, Baumeister S, Lingelbach K, Bauer S. TLR8 is activated by 5'-methylthioinosine, a Plasmodium falciparum-derived intermediate of the purine salvage pathway. Cell Rep 2022; 39:110691. [PMID: 35417716 DOI: 10.1016/j.celrep.2022.110691] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 02/02/2022] [Accepted: 03/25/2022] [Indexed: 12/31/2022] Open
Abstract
The innate immune recognition of the malaria-causing pathogen Plasmodium falciparum (P. falciparum) is not fully explored. Here, we identify the nucleoside 5'-methylthioinosine (MTI), a Plasmodium-specific intermediate of the purine salvage pathway, as a pathogen-derived Toll-like receptor 8 (TLR8) agonist. Co-incubation of MTI with the TLR8 enhancer poly(dT) as well as synthetic or P. falciparum-derived RNA strongly increase its stimulatory activity. Of note, MTI generated from methylthioadenosine (MTA) by P. falciparum lysates activates TLR8 when MTI metabolism is inhibited by immucillin targeting the purine nucleoside phosphorylase (PfPNP). Importantly, P. falciparum-infected red blood cells incubated with MTI or cultivated with MTA and immucillin lead to TLR8-dependent interleukin-6 (IL-6) production in human monocytes. Our data demonstrate that the nucleoside MTI is a natural human TLR8 ligand with possible in vivo relevance for innate sensing of P. falciparum.
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Affiliation(s)
- Gabriele Köllisch
- Department of Parasitology, Philipps University Marburg, 35043 Marburg, Germany
| | | | - Hannah-Lena Obermann
- Institute for Immunology, Philipps University Marburg, BMFZ, 35043 Marburg, Germany
| | - Jeannine Eckert
- Department of Parasitology, Philipps University Marburg, 35043 Marburg, Germany
| | - Thomas Müller
- Institute for Medical Microbiology, Immunology und Hygiene, Technical University Munich, Munich, Germany
| | - Tim Vierbuchen
- Division of Innate Immunity, Research Center Borstel, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Borstel, Germany
| | - Thomas Rickmeyer
- Institute for Pharmaceutical Chemistry, Philipps University Marburg, 35043 Marburg, Germany
| | - Simon Muche
- Department of Chemistry, Philipps University Marburg, 35043 Marburg, Germany
| | - Jude M Przyborski
- Department of Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Giessen, Germany
| | - Holger Heine
- Division of Innate Immunity, Research Center Borstel, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Borstel, Germany
| | - Andreas Kaufmann
- Institute for Immunology, Philipps University Marburg, BMFZ, 35043 Marburg, Germany
| | - Stefan Baumeister
- Department of Parasitology, Philipps University Marburg, 35043 Marburg, Germany
| | - Klaus Lingelbach
- Department of Parasitology, Philipps University Marburg, 35043 Marburg, Germany
| | - Stefan Bauer
- Institute for Immunology, Philipps University Marburg, BMFZ, 35043 Marburg, Germany.
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18
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Hu Z, Zhang T, Jiang S, Yin H. Protocol for evaluation and validation of TLR8 antagonists in HEK-Blue cells via secreted embryonic alkaline phosphatase assay. STAR Protoc 2022; 3:101061. [PMID: 35005643 PMCID: PMC8715332 DOI: 10.1016/j.xpro.2021.101061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Toll-like receptor 8 (TLR8) is a pattern recognition receptor that senses RNA degradation products and initiates immune responses. TLR8 overactivation is associated with autoimmune diseases. Herein, we describe the evaluation and validation of TLR8 antagonists in HEK-Blue cells via secreted embryonic alkaline phosphatase (SEAP) assay, WST assay, ITC and immunoblotting. These assays can facilitate the development of TLR8 antagonists; this protocol can also be adapted to analyze agonists and antagonists for other TLRs. For complete details on the use and execution of this protocol, please refer to Hu et al. (2018). A protocol for secreted embryonic alkaline phosphatase assay for TLR8 inhibition Validation of TLR8 antagonist specificity Validation of TLR8 antagonist induced downstream signaling inhibition
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Affiliation(s)
- Zhenyi Hu
- School of Pharmaceutical Sciences, Tsinghua University, 100084 Beijing, China
- Corresponding author
| | - Tuan Zhang
- School of Pharmaceutical Sciences, Tsinghua University, 100084 Beijing, China
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, 100084 Beijing, China
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, 100084 Beijing, China
| | - Shuangshuang Jiang
- School of Pharmaceutical Sciences, Tsinghua University, 100084 Beijing, China
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, 100084 Beijing, China
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, 100084 Beijing, China
| | - Hang Yin
- School of Pharmaceutical Sciences, Tsinghua University, 100084 Beijing, China
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, 100084 Beijing, China
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, 100084 Beijing, China
- Corresponding author
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19
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Khan N, Halcrow PW, Afghah Z, Baral A, Geiger J, Chen X. HIV-1 Tat endocytosis and retention in endolysosomes affects HIV-1 Tat-induced LTR transactivation in astrocytes. FASEB J 2022; 36:e22184. [PMID: 35113458 PMCID: PMC9627655 DOI: 10.1096/fj.202101722r] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 01/13/2022] [Accepted: 01/18/2022] [Indexed: 11/11/2022]
Abstract
The presence of latent HIV-1 reservoirs in the periphery and brain represents a major obstacle to curing HIV-1 infection. As an essential protein for HIV-1 viral replication, HIV-1 Tat, mostly intracellular, has been implicated in latent HIV-1 infection. From HIV-1 infected cells, HIV-1 Tat is actively secreted and bystander cells uptake the released Tat whereupon it is endocytosed and internalized into endolysosomes. However, to activate the HIV-1 LTR promoter and increase HIV-1 replication, HIV-1 Tat must first escape from the endolysosomes and then enter the nucleus. Here, we tested the hypothesis that HIV-1 Tat can accumulate in endolysosomes and contribute to the activation of latent HIV-1 in astrocytes. Using U87MG astrocytoma cells expressing HIV-1 LTR-driven luciferase and primary human astrocytes we found that exogenous HIV-1 Tat enters endolysosomes, resides in endolysosomes for extended periods of time, and induces endolysosome de-acidification as well as enlargement. The weak base chloroquine promoted the release of HIV-1 Tat from endolysosomes and induced HIV-1 LTR transactivation. Similar results were observed by activating endolysosome Toll-like receptor 3 (TLR3) and TLR7/8. Conversely, pharmacological block of TLRs and knocking down expression levels of TLR3 and TLR7, but not TLR8, prevented endolysosome leakage and attenuated HIV-1 Tat-mediated HIV-1 LTR transactivation. Our findings suggest that HIV-1 Tat accumulation in endolysosomes may play an important role in controlling HIV-1 transactivation.
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Affiliation(s)
- Nabab Khan
- Department of Biomedical Sciences University of North Dakota School of Medicine and Health Sciences Grand Forks North Dakota USA
| | - Peter W. Halcrow
- Department of Biomedical Sciences University of North Dakota School of Medicine and Health Sciences Grand Forks North Dakota USA
| | - Zahra Afghah
- Department of Biomedical Sciences University of North Dakota School of Medicine and Health Sciences Grand Forks North Dakota USA
| | - Aparajita Baral
- Department of Biomedical Sciences University of North Dakota School of Medicine and Health Sciences Grand Forks North Dakota USA
| | - Jonathan D. Geiger
- Department of Biomedical Sciences University of North Dakota School of Medicine and Health Sciences Grand Forks North Dakota USA
| | - Xuesong Chen
- Department of Biomedical Sciences University of North Dakota School of Medicine and Health Sciences Grand Forks North Dakota USA
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20
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Hansur L, Louisa M, Wuyung PE, Fadilah F. Daphnoretin from Carthamus tinctorius as a Potential Inflammatory Inhibitor in COVID-19 by Binding to Toll-like Receptor-4: An in silico Molecular Docking Study. Open Access Maced J Med Sci 2022. [DOI: 10.3889/oamjms.2022.7961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND: Cytokine storm in COVID-19 patients has contributed to many morbidities and mortalities in patients. Studies have found that toll-like receptors (TLRs) and some Fc receptors play essential roles in the hyperactivation of the immune system. Up to date, researchers are still in progress to discover effective and safe drugs to alleviate the hyperinflammatory state in COVID-19. The previous studies had shown that Carthamus tinctorius and its bioactive compounds might have anti-inflammatory activities in animal models.
AIM: We aimed to investigate the possible interactions of several flavonoids from C. tinctorius with several immune system components using a biocomputational approach.
METHODS: Molecular docking was done using the AutoDock program based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) COVID-19 pathway. The most suitable receptors found were studied to study the interactions with several flavonoids from C. tinctorius.
RESULTS: TLR4, TLR8, and FcγRIIa were found to bind with SARS CoV2 inflammatory pathway and further selected as macromolecules for potential interactions study with 22 flavonoids from C. tinctorius. Of the 22 flavonoids studied, daphnoretin showed the best binding affinity with TLR4 and Rutin was shown to attach best with FcγRIIa. Unlike its excellent binding to TLR4, daphnoretin showed weak binding to TLR8.
CONCLUSION: Daphnoretin showed an excellent affinity with TLR4 and might be a good candidate as an inhibitor in hyperinflammatory reactions in COVID-19 DTLR8.
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21
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Activation of Innate Immunity by Therapeutic Nucleic Acids. Int J Mol Sci 2021; 22:ijms222413360. [PMID: 34948156 PMCID: PMC8704878 DOI: 10.3390/ijms222413360] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 12/07/2021] [Accepted: 12/09/2021] [Indexed: 12/24/2022] Open
Abstract
Nucleic acid-based therapeutics have gained increased attention during recent decades because of their wide range of application prospects. Immunostimulatory nucleic acids represent a promising class of potential drugs for the treatment of tumoral and viral diseases due to their low toxicity and stimulation of the body’s own innate immunity by acting on the natural mechanisms of its activation. The repertoire of nucleic acids that directly interact with the components of the immune system is expanding with the improvement of both analytical methods and methods for the synthesis of nucleic acids and their derivatives. Despite the obvious progress in this area, the problem of delivering therapeutic acids to target cells as well as the unresolved issue of achieving a specific therapeutic effect based on activating the mechanism of interferon and anti-inflammatory cytokine synthesis. Minimizing the undesirable effects of excessive secretion of inflammatory cytokines remains an unsolved task. This review examines recent data on the types of immunostimulatory nucleic acids, the receptors interacting with them, and the mechanisms of immunity activation under the action of these molecules. Finally, data on immunostimulatory nucleic acids in ongoing and completed clinical trials will be summarized.
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22
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Dolšak A, Šribar D, Scheffler A, Grabowski M, Švajger U, Gobec S, Holze J, Weindl G, Wolber G, Sova M. Further hit optimization of 6-(trifluoromethyl)pyrimidin-2-amine based TLR8 modulators: Synthesis, biological evaluation and structure-activity relationships. Eur J Med Chem 2021; 225:113809. [PMID: 34488023 DOI: 10.1016/j.ejmech.2021.113809] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/13/2021] [Accepted: 08/24/2021] [Indexed: 12/26/2022]
Abstract
Toll-like receptor 8 (TLR8) is an endosomal TLR that has an important role in the innate human immune system, which is involved in numerous pathological conditions. Excessive activation of TLR8 can lead to inflammatory and autoimmune diseases, which highlights the need for development of TLR8 modulators. However, only a few small-molecule modulators that selectively target TLR8 have been developed. Here, we report the synthesis and systematic investigation of the structure-activity relationships of a series of novel TLR8 negative modulators based on previously reported 6-(trifluoromethyl)pyrimidin-2-amine derivatives. Four compounds showed low-micromolar concentration-dependent inhibition of TLR8-mediated signaling in HEK293 cells. These data confirm that the 6-trifluoromethyl group and two other substituents on positions 2 and 4 are important structural elements of pyrimidine-based TLR8 modulators. Substitution of the main scaffold at position 2 with a methylsulfonyl group or para hydroxy/hydroxymethyl substituted benzylamine is essential for potent negative modulation of TLR8. Our best-in-class TLR8-selective modulator 53 with IC50 value of 6.2 μM represents a promising small-molecule chemical probe for further optimization to a lead compound with potent immunomodulatory properties.
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Affiliation(s)
- Ana Dolšak
- Chair of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana, Aškerčeva c. 7, SI-1000, Ljubljana, Slovenia
| | - Dora Šribar
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195, Berlin, Germany
| | - Alexander Scheffler
- Pharmacology and Toxicology Section, Pharmaceutical Institute, University of Bonn, Gerhard-Domagk-Str. 3, 53121, Bonn, Germany
| | - Maria Grabowski
- Pharmacology and Toxicology, Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195, Berlin, Germany
| | - Urban Švajger
- Blood Transfusion Centre of Slovenia, Šlajmerjeva 6, 1000, Ljubljana, Slovenia
| | - Stanislav Gobec
- Chair of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana, Aškerčeva c. 7, SI-1000, Ljubljana, Slovenia
| | - Janine Holze
- Pharmacology and Toxicology Section, Pharmaceutical Institute, University of Bonn, Gerhard-Domagk-Str. 3, 53121, Bonn, Germany
| | - Günther Weindl
- Pharmacology and Toxicology Section, Pharmaceutical Institute, University of Bonn, Gerhard-Domagk-Str. 3, 53121, Bonn, Germany.
| | - Gerhard Wolber
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195, Berlin, Germany.
| | - Matej Sova
- Chair of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana, Aškerčeva c. 7, SI-1000, Ljubljana, Slovenia.
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23
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Yang Y, Luo S, Huang J, Xiao Y, Fu Y, Liu W, Yin H. Photoactivation of Innate Immunity Receptor TLR8 in Live Mammalian Cells by Genetic Encoding of Photocaged Tyrosine. Chembiochem 2021; 23:e202100344. [PMID: 34460982 DOI: 10.1002/cbic.202100344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/10/2021] [Indexed: 11/10/2022]
Abstract
The effectiveness of innate immune responses relies on an intricate balance between activation and regulation. TLR8, a member of the Toll-like receptor (TLR) family, plays a fundamental role in host defense by sensing viral single-stranded RNAs (ssRNAs). However, the molecular recognition and regulatory mechanism of TLR8 is not fully understood, especially in a whole-cell environment. Here, we engineer the first light-controllable TLR8 model by genetically encoding a photocaged tyrosine, NBY, into specific sites of TLR8. In the caged forms, the activity of TLR8 is masked but can be restored upon decaging by exposure to UV light. To explain the mechanism clearly, we divide the sites with light responsiveness into three groups. They can separately block the ligands that bind to the pockets of TLR8, change the interaction modes between two TLR8 protomers, and interfere with the interactions between TLR8 cytosolic domains with its downstream adaptor. Specifically, we use this chemical caging strategy to probe and evaluate the function of several tyrosine sites located at the interface of TLR8 homodimers with a previously unknown regulatory mode, which may provide a new strategy for TLR8 modulator development. Effects on downstream signaling pathways are monitored at the transcriptional and translational levels in various cell lines. By photoactivating specific cells within a larger population, this powerful tool can provide novel mechanistic insights, with potential in biotechnological and pharmaceutical applications.
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Affiliation(s)
- Yi Yang
- Department of Chemistry, School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, P. R. China
| | - Shuchen Luo
- Department of Chemistry, School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, P. R. China
| | - Jian Huang
- Department of Chemistry, School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, P. R. China
| | - Yu Xiao
- Department of Chemistry, School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, P. R. China.,Zhujiang Hospital, Laboratory of Medicine Center, Southern Medical University, Guangzhou, 510282, P. R. China
| | - Yixuan Fu
- Department of Chemistry, School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, P. R. China
| | - Wei Liu
- Department of Chemistry, School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, P. R. China
| | - Hang Yin
- Department of Chemistry, School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, P. R. China
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24
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Tetrasubstituted imidazoles as incognito Toll-like receptor 8 a(nta)gonists. Nat Commun 2021; 12:4351. [PMID: 34272380 PMCID: PMC8285539 DOI: 10.1038/s41467-021-24536-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 06/21/2021] [Indexed: 12/20/2022] Open
Abstract
Small-molecule modulators of TLR8 have drawn much interests as it plays pivotal roles in the innate immune response to single-stranded RNAs (ssRNAs) derived from viruses. However, their clinical uses are limited because they can invoke an uncontrolled, global inflammatory response. The efforts described herein culminate in the fortuitous discovery of a tetrasubstituted imidazole CU-CPD107 which inhibits R848-induced TLR8 signaling. In stark contrast, CU-CPD107 shows unexpected synergistic agonist activities in the presence of ssRNA, while CU-CPD107 alone is unable to influence TLR8 signaling. CU-CPD107’s unique, dichotomous behavior sheds light on a way to approach TLR agonists. CU-CPD107 offers the opportunity to avoid the undesired, global inflammation side effects that have rendered imidazoquinolines clinically irrelevant, providing an insight for the development of antiviral drugs. Toll-like receptor 8 (TLR8) plays essential roles in the innate immune response to viral single-stranded RNA (ssRNA), so small molecule modulators of TLR8 are of interest, however adverse effects limit their use. Here, the authors report a tetrasubstituted imidazole CU-CPD107 with dichotomous behaviour, which inhibits R848-induced TLR8 signaling, but shows synergistic activity in the presence of ssRNA, making it a potential antiviral agent.
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25
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Talukdar A, Ganguly D, Roy S, Das N, Sarkar D. Structural Evolution and Translational Potential for Agonists and Antagonists of Endosomal Toll-like Receptors. J Med Chem 2021; 64:8010-8041. [PMID: 34107682 DOI: 10.1021/acs.jmedchem.1c00300] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Toll-like receptors (TLRs) are members of a large family of evolutionarily conserved pattern recognition receptors (PRRs), which serve as key components of the innate immune system by playing a pivotal role in sensing "nonself" ligands. Endosomal TLRs (TLR3, TLR7, TLR8, and TLR9) can recognize pathogen-derived nucleic acid and initiate an innate immune response because they react against both self- and non-self-origin nucleic acid molecules. Accordingly, both receptor agonists and antagonists are potentially useful in disparate clinical contexts and thus are globally sought after. Recent research has revealed that agonists and antagonists share an overlapping binding region. This Perspective highlights rational medicinal chemistry approaches to elucidate the structural attributes of small molecules capable of agonism or antagonism or of elegantly switching between the two. The structural evolution of different chemotypes can provide the framework for the future development of endosomal TLR agonists and antagonists.
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Affiliation(s)
- Arindam Talukdar
- Department of Organic and Medicinal Chemistry, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700032, West Bengal, India.,Academy of Scientific and Innovative Research, Ghaziabad 201002, Uttar Pradesh, India
| | - Dipyaman Ganguly
- IICB-Translational Research Unit of Excellence, Department of Cancer Biology and Inflammatory Disorders, CSIR-Indian Institute of Chemical Biology, CN6, Sector V, Salt Lake, Kolkata 700091, West Bengal, India.,Academy of Scientific and Innovative Research, Ghaziabad 201002, Uttar Pradesh, India
| | - Swarnali Roy
- Department of Organic and Medicinal Chemistry, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700032, West Bengal, India
| | - Nirmal Das
- Department of Organic and Medicinal Chemistry, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700032, West Bengal, India.,Academy of Scientific and Innovative Research, Ghaziabad 201002, Uttar Pradesh, India
| | - Dipika Sarkar
- Department of Organic and Medicinal Chemistry, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700032, West Bengal, India
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26
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Wang X, Liu Y, Han X, Zou G, Zhu W, Shen H, Liu H. Small molecule approaches to treat autoimmune and inflammatory diseases (Part II): Nucleic acid sensing antagonists and inhibitors. Bioorg Med Chem Lett 2021; 44:128101. [PMID: 33984476 DOI: 10.1016/j.bmcl.2021.128101] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 05/05/2021] [Accepted: 05/05/2021] [Indexed: 02/06/2023]
Abstract
Nucleic acid sensing pathways play an important role in the innate immune system, protecting hosts against infections. However, a large body of evidence supports a close association between aberrant activation of those pathways and autoimmune and inflammatory diseases. Part II of the digest series on small molecule approaches to autoimmune and inflammatory diseases concentrates on recent advances with respect to small molecule antagonists or inhibitors of the nucleic acid sensing pathways, including endosomal TLRs, NLRP3 inflammasome and cGAS-STING.
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Affiliation(s)
- Xiaoqing Wang
- Department of Medicinal Chemistry, Roche Innovation Center Shanghai, Roche Pharma Research and Early Development, Shanghai 201203, China
| | - Yafei Liu
- Department of Medicinal Chemistry, Roche Innovation Center Shanghai, Roche Pharma Research and Early Development, Shanghai 201203, China
| | - Xingchun Han
- Department of Medicinal Chemistry, Roche Innovation Center Shanghai, Roche Pharma Research and Early Development, Shanghai 201203, China
| | - Ge Zou
- Department of Medicinal Chemistry, Roche Innovation Center Shanghai, Roche Pharma Research and Early Development, Shanghai 201203, China
| | - Wei Zhu
- Department of Medicinal Chemistry, Roche Innovation Center Shanghai, Roche Pharma Research and Early Development, Shanghai 201203, China
| | - Hong Shen
- Department of Medicinal Chemistry, Roche Innovation Center Shanghai, Roche Pharma Research and Early Development, Shanghai 201203, China
| | - Haixia Liu
- Department of Medicinal Chemistry, Roche Innovation Center Shanghai, Roche Pharma Research and Early Development, Shanghai 201203, China.
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27
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Asami J, Shimizu T. Structural and functional understanding of the toll-like receptors. Protein Sci 2021; 30:761-772. [PMID: 33576548 DOI: 10.1002/pro.4043] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 02/09/2021] [Accepted: 02/09/2021] [Indexed: 12/11/2022]
Abstract
Recognition of invading pathogens by the innate immune system is essential to initiate antimicrobial responses and trigger adaptive immunity. This is largely mediated by an array of pattern-recognition receptor families that are essential for recognizing conserved molecular motifs characteristic of pathogenic microbes. One such family is the Toll-like receptors (TLRs). Activation of TLRs induces production of pro-inflammatory cytokines and type I interferons: the former triggers the synthesis of inflammatory mediators which cause fever, pain and other inflammation, and the latter mediates antiviral responses. Over the past decade, significant progress has been made in structural elucidation of TLRs in higher eukaryotes. The TLR structures with and without agonist and antagonist have been revealed by X-ray crystallography and cryo-electron microscopy studies, demonstrating the activated dimer formation induced by the agonistic ligand and the inhibition mechanism of the antagonistic ligand. Intracellular assembled structures and the TLR-chaperone complex are also reported. As the structural understanding of TLRs becomes better integrated with biochemical and immunological studies, a more comprehensive picture of their architectural and functional properties will emerge. This review summarizes recent advances in structural biological and mechanistic studies on TLRs.
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Affiliation(s)
- Jinta Asami
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Toshiyuki Shimizu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
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28
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Knoepfel T, Nimsgern P, Jacquier S, Bourrel M, Vangrevelinghe E, Glatthar R, Behnke D, Alper PB, Michellys PY, Deane J, Junt T, Zipfel G, Limonta S, Hawtin S, Andre C, Boulay T, Loetscher P, Faller M, Blank J, Feifel R, Betschart C. Target-Based Identification and Optimization of 5-Indazol-5-yl Pyridones as Toll-like Receptor 7 and 8 Antagonists Using a Biochemical TLR8 Antagonist Competition Assay. J Med Chem 2020; 63:8276-8295. [PMID: 32786235 DOI: 10.1021/acs.jmedchem.0c00130] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Inappropriate activation of endosomal TLR7 and TLR8 occurs in several autoimmune diseases, in particular systemic lupus erythematosus (SLE). Herein, the development of a TLR8 antagonist competition assay and its application for hit generation of dual TLR7/8 antagonists are reported. The structure-guided optimization of the pyridone hit 3 using this biochemical assay in combination with cellular and TLR8 cocrystal structural data resulted in the identification of a highly potent and selective TLR7/8 antagonist (27) with in vivo efficacy. The two key steps for optimization were (i) a core morph guided by a TLR7 sequence alignment to achieve a dual TLR7/8 antagonism profile and (ii) introduction of a fluorine in the piperidine ring to reduce its basicity, resulting in attractive oral pharmacokinetic (PK) properties and improved TLR8 binding affinity.
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Affiliation(s)
| | | | | | | | | | | | | | - Phil B Alper
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
| | - Pierre-Yves Michellys
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
| | - Jonathan Deane
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
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29
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Sakaniwa K, Shimizu T. Targeting the innate immune receptor TLR8 using small-molecule agents. Acta Crystallogr D Struct Biol 2020; 76:621-629. [PMID: 32627735 PMCID: PMC7336380 DOI: 10.1107/s2059798320006518] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 05/15/2020] [Indexed: 12/19/2022] Open
Abstract
Toll-like receptors (TLRs) are pattern-recognition receptors that initiate innate immune responses. Among the TLRs, TLR8 (and TLR7) recognizes single-stranded RNA to mediate downstream signals. In recent years, intensive X-ray crystal structural analyses have provided atomic insights into structures of TLR8 complexed with various agonists or antagonists. Here, structural knowledge of the activation and inactivation mechanisms of the ligands is reviewed. In addition, the potential clinical applications of TLR ligands are examined.
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Affiliation(s)
- Kentaro Sakaniwa
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Toshiyuki Shimizu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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30
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Wang Y, Zhang S, Li H, Wang H, Zhang T, Hutchinson MR, Yin H, Wang X. Small-Molecule Modulators of Toll-like Receptors. Acc Chem Res 2020; 53:1046-1055. [PMID: 32233400 DOI: 10.1021/acs.accounts.9b00631] [Citation(s) in RCA: 132] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Toll-like receptors (TLRs) are the "gatekeepers" of the immune system in humans and other animals to protect the host from invading bacteria, viruses, and other microorganisms. Since TLR4 was discovered as the receptor for endotoxin in the late 1990s, significant progress has been made in exploiting an understanding of the function of TLRs. The TLR-signaling pathway is crucial for the induction and progression of various diseases. Dysregulation of TLR signaling contributes to numerous pathological conditions, including chronic inflammation, sepsis, cancers, asthma, neuropathic pain, drug addiction, and autoimmune diseases. Therefore, manipulation of TLR signaling is promising to halt their activity in inflammatory diseases, to enhance their signaling to fight cancers, to modulate their role in autoimmune diseases, and to suppress them to treat drug addiction. TLR agonists have demonstrated great potential as antimicrobial agents and vaccine adjuvants, whereas TLR antagonists are being developed as reagents and drugs to dampen immune responses. Because of their pivotal potential therapeutic applications, fruitful small-molecule compounds and peptide fragments have been discovered, and many of them have advanced to various stages of clinical trials (though only two have been approved by the Food and Drug Administration (FDA): MPLA as a TLR4 agonist and imiquimod as a TLR7 agonist).In this Account, we focus on the progress in developing TLR signaling pathway modulators (mainly focused on the Yin and Wang laboratories) over the past decade and highlight the accomplishments and currently existing challenges in the development of TLR modulators. First, we briefly describe the members of the human TLR family along with their natural modulators. Second, we illustrate our endeavors to discover TLR-targeted agents using comprehensive approaches. Specifically, a discussion of identification and characterization of new chemical entities, determination of modes of action, and further applications is presented. For instance, the TLR3 antagonist was first discovered through in silico screening, and the inhibitory activity was confirmed in murine cells. Considering the glycosylation on TLR3, a new direction for TLR3 modulator design was pointed out to target asparagine glycosylation. We have particularly focused on the discovery of TLR4 antagonists and have assessed their great potential in the clinical treatment of drug addiction and alcohol use disorders. In addition, we discuss multiple other popular and robust techniques for modulator discovery. Not only small organic modulators but also stapled peptides and peptidomimetics will attract more and more attention in the future. Finally, current challenges, opportunities, and future perspectives for TLR-targeted agents are also discussed.
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Affiliation(s)
- Yibo Wang
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
| | - Shuting Zhang
- School of Pharmaceutical Sciences, Tsinghua University−Peking University Joint Center for Life Sciences, Tsinghua University, Beijing 100082, China
| | - Hongyuan Li
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
| | - Hongshuang Wang
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
| | - Tianshu Zhang
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
| | - Mark R. Hutchinson
- Discipline of Physiology, Adelaide Medical School, and ARC Centre of Excellence for Nanoscale BioPhotonics, University of Adelaide, Adelaide, South Australia 5000, Australia
| | - Hang Yin
- School of Pharmaceutical Sciences, Tsinghua University−Peking University Joint Center for Life Sciences, Tsinghua University, Beijing 100082, China
| | - Xiaohui Wang
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
- Department of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China
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31
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Jiang S, Tanji H, Yin K, Zhang S, Sakaniwa K, Huang J, Yang Y, Li J, Ohto U, Shimizu T, Yin H. Rationally Designed Small-Molecule Inhibitors Targeting an Unconventional Pocket on the TLR8 Protein-Protein Interface. J Med Chem 2020; 63:4117-4132. [PMID: 32233366 DOI: 10.1021/acs.jmedchem.9b02128] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Rational designs of small-molecule inhibitors targeting protein-protein interfaces have met little success. Herein, we have designed a series of triazole derivatives with a novel scaffold to specifically intervene with the interaction of TLR8 homomerization. In multiple assays, TH1027 was identified as a highly potent and specific inhibitor of TLR8. A successful solution of the X-ray crystal structure of TLR8 in complex with TH1027 provided an in-depth mechanistic insight into its binding mode, validating that TH1027 was located between two TLR8 monomers and recognized as an unconventional pocket, thereby preventing TLR8 from activation. Further biological evaluations showed that TH1027 dose-dependently suppressed the TLR8-mediated inflammatory responses in both human monocyte cell lines, peripheral blood mononuclear cells, and rheumatoid arthritis patient specimens, suggesting a strong therapeutic potential against autoimmune diseases.
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Affiliation(s)
| | - Hiromi Tanji
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | | | | | - Kentaro Sakaniwa
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | | | | | - Jing Li
- Department of Rheumatology and Clinical Immunology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, National Clinical Research Center for Dermatologic and Immunologic Diseases (NCRC-DID), Beijing 100730, China
| | - Umeharu Ohto
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Toshiyuki Shimizu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
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32
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Meås HZ, Haug M, Beckwith MS, Louet C, Ryan L, Hu Z, Landskron J, Nordbø SA, Taskén K, Yin H, Damås JK, Flo TH. Sensing of HIV-1 by TLR8 activates human T cells and reverses latency. Nat Commun 2020; 11:147. [PMID: 31919342 PMCID: PMC6952430 DOI: 10.1038/s41467-019-13837-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 12/02/2019] [Indexed: 12/31/2022] Open
Abstract
During HIV infection, cell-to-cell transmission results in endosomal uptake of the virus by target CD4+ T cells and potential exposure of the viral ssRNA genome to endosomal Toll-like receptors (TLRs). TLRs are instrumental in activating inflammatory responses in innate immune cells, but their function in adaptive immune cells is less well understood. Here we show that synthetic ligands of TLR8 boosted T cell receptor signaling, resulting in increased cytokine production and upregulation of surface activation markers. Adjuvant TLR8 stimulation, but not TLR7 or TLR9, further promoted T helper cell differentiation towards Th1 and Th17. In addition, we found that endosomal HIV induced cytokine secretion from CD4+ T cells in a TLR8-specific manner. TLR8 engagement also enhanced HIV-1 replication and potentiated the reversal of latency in patient-derived T cells. The adjuvant TLR8 activity in T cells can contribute to viral dissemination in the lymph node and low-grade inflammation in HIV patients. In addition, it can potentially be exploited for therapeutic targeting and vaccine development.
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Affiliation(s)
- Hany Zekaria Meås
- Centre of Molecular Inflammation Research, Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Infectious Diseases, St. Olavs Hospital, Trondheim, Norway
| | - Markus Haug
- Centre of Molecular Inflammation Research, Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Infectious Diseases, St. Olavs Hospital, Trondheim, Norway
| | - Marianne Sandvold Beckwith
- Centre of Molecular Inflammation Research, Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Claire Louet
- Centre of Molecular Inflammation Research, Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Liv Ryan
- Centre of Molecular Inflammation Research, Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Zhenyi Hu
- School of Pharmaceutical Sciences, Tsinghua University-Peking University Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, 100082, Beijing, China.,Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Johannes Landskron
- Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Svein Arne Nordbø
- Centre of Molecular Inflammation Research, Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Medical Microbiology, St. Olavs Hospital, Trondheim, Norway
| | - Kjetil Taskén
- Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of Oslo and Oslo University Hospital, Oslo, Norway.,Department of Cancer Immunology, Institute of Cancer Research, Oslo University Hospital, Oslo, Norway.,K.G. Jebsen Centre for Cancer Immunotherapy, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Hang Yin
- School of Pharmaceutical Sciences, Tsinghua University-Peking University Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, 100082, Beijing, China
| | - Jan Kristian Damås
- Centre of Molecular Inflammation Research, Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Infectious Diseases, St. Olavs Hospital, Trondheim, Norway
| | - Trude Helen Flo
- Centre of Molecular Inflammation Research, Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway. .,Department of Infectious Diseases, St. Olavs Hospital, Trondheim, Norway. .,Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of Oslo and Oslo University Hospital, Oslo, Norway.
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33
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Padilla-Salinas R, Anderson R, Sakaniwa K, Zhang S, Nordeen P, Lu C, Shimizu T, Yin H. Discovery of Novel Small Molecule Dual Inhibitors Targeting Toll-Like Receptors 7 and 8. J Med Chem 2019; 62:10221-10244. [DOI: 10.1021/acs.jmedchem.9b01201] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Rosaura Padilla-Salinas
- Department of Chemistry and Biochemistry and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Rachel Anderson
- Department of Chemistry and Biochemistry and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Kentaro Sakaniwa
- Graduate School of Pharmaceuticals Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Shuting Zhang
- School of Pharmaceutical Sciences, Tsinghua University-Peking University Joint Center of Life Science, Tsinghua University, Beijing 100082, China
| | - Patrick Nordeen
- Department of Chemistry and Biochemistry and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Chuanjun Lu
- Department of Chemistry and Biochemistry and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Toshiyuki Shimizu
- Graduate School of Pharmaceuticals Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Hang Yin
- Department of Chemistry and Biochemistry and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80309, United States
- School of Pharmaceutical Sciences, Tsinghua University-Peking University Joint Center of Life Science, Tsinghua University, Beijing 100082, China
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34
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Šribar D, Grabowski M, Murgueitio MS, Bermudez M, Weindl G, Wolber G. Identification and characterization of a novel chemotype for human TLR8 inhibitors. Eur J Med Chem 2019; 179:744-752. [DOI: 10.1016/j.ejmech.2019.06.084] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 06/27/2019] [Accepted: 06/28/2019] [Indexed: 10/26/2022]
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35
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The Bacterial Product Violacein Exerts an Immunostimulatory Effect Via TLR8. Sci Rep 2019; 9:13661. [PMID: 31541142 PMCID: PMC6754391 DOI: 10.1038/s41598-019-50038-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 07/19/2019] [Indexed: 12/28/2022] Open
Abstract
Violacein, an indole-derived, purple-colored natural pigment isolated from Chromobacterium violaceum has shown multiple biological activities. In this work, we studied the effect of violacein in different immune cell lines, namely THP-1, MonoMac 6, ANA-1, Raw 264.7 cells, as well as in human peripheral blood mononuclear cells (PBMCs). A stimulation of TNF-α production was observed in murine macrophages (ANA-1 and Raw 264.7), and in PBMCs, IL-6 and IL-1β secretion was detected. We obtained evidence of the molecular mechanism of activation by determining the mRNA expression pattern upon treatment with violacein in Raw 264.7 cells. Incubation with violacein caused activation of pathways related with an immune and inflammatory response. Our data utilizing TLR-transfected HEK-293 cells indicate that violacein activates the human TLR8 (hTLR8) receptor signaling pathway and not human TLR7 (hTLR7). Furthermore, we found that the immunostimulatory effect of violacein in PBMCs could be suppressed by the specific hTLR8 antagonist, CU-CPT9a. Finally, we studied the interaction of hTLR8 with violacein in silico and obtained evidence that violacein could bind to hTLR8 in a similar fashion to imidazoquinoline compounds. Therefore, our results indicate that violacein may have some potential in contributing to future immune therapy strategies.
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36
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Biber K, Bhattacharya A, Campbell BM, Piro JR, Rohe M, Staal RGW, Talanian RV, Möller T. Microglial Drug Targets in AD: Opportunities and Challenges in Drug Discovery and Development. Front Pharmacol 2019; 10:840. [PMID: 31507408 PMCID: PMC6716448 DOI: 10.3389/fphar.2019.00840] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 07/01/2019] [Indexed: 12/20/2022] Open
Abstract
Alzheimer’s disease (AD) is a large and increasing unmet medical need with no disease-modifying treatment currently available. Genetic evidence from genome-wide association studies (GWASs) and gene network analysis has clearly revealed a key role of the innate immune system in the brain, of which microglia are the most important element. Single-nucleotide polymorphisms (SNPs) in genes predominantly expressed in microglia have been associated with altered risk of developing AD. Furthermore, microglia-specific pathways are affected on the messenger RNA (mRNA) expression level in post-mortem AD tissue and in mouse models of AD. Together these findings have increased the interest in microglia biology, and numerous scientific reports have proposed microglial molecules and pathways as drug targets for AD. Target identification and validation are generally the first steps in drug discovery. Both target validation and drug lead identification for central nervous system (CNS) targets and diseases entail additional significant obstacles compared to peripheral targets and diseases. This makes CNS drug discovery, even with well-validated targets, challenging. In this article, we will illustrate the special challenges of AD drug discovery by discussing the viability/practicality of possible microglia drug targets including cluster of differentiation 33 (CD33), KCa3.1, kynurenines, ionotropic P2 receptor 7 (P2X7), programmed death-1 (PD-1), Toll-like receptors (TLRs), and triggering receptor expressed in myeloid cells 2 (TREM2).
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Affiliation(s)
- Knut Biber
- AbbVie Deutschland GmbH & Co. KG, Neuroscience Research, Ludwigshafen, Germany
| | | | | | - Justin R Piro
- AbbVie Foundational Neuroscience Center, Cambridge, MA, United States
| | - Michael Rohe
- AbbVie Deutschland GmbH & Co. KG, Neuroscience Research, Ludwigshafen, Germany
| | | | - Robert V Talanian
- AbbVie Foundational Neuroscience Center, Cambridge, MA, United States
| | - Thomas Möller
- AbbVie Foundational Neuroscience Center, Cambridge, MA, United States
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37
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Huang S, Mei H, Zhang D, Shi T, Chen L, Kuang Z, Heng Y, Pan X, Lu L. Subtle differences in chemical pattern between human toll-like receptor 8 agonists and antagonists: Emerging chemical patterns analysis. Chem Biol Drug Des 2019; 94:1824-1834. [PMID: 31293023 DOI: 10.1111/cbdd.13590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 06/17/2019] [Accepted: 07/03/2019] [Indexed: 12/18/2022]
Abstract
Due to the potencies in the treatments of cancer, infectious diseases, and autoimmune diseases, the developments of human TLR8 (hTLR8) agonists and antagonists have attracted widespread attentions. The hTLR8 agonists and antagonists have similar structures but with completely opposite biological effects. Up to date, the subtle differences in the structures between the hTLR8 agonists and antagonists are still unknown. In this work, emerging chemical pattern (ECP) was successfully used to extract the key chemical patterns of the hTLR8 agonists and antagonists. By using CAEP classifier, an optimal ECP model with only 3 descriptors was established with the overall prediction accuracy larger than 90%. Further hierarchical cluster analysis and molecular docking showed that the H-bond and hydrophobic properties are the key features distinguishing the hTLR8 agonists from antagonists. Comparing with the antagonists, the agonists show stronger specific H-bond properties, while antagonists have stronger non-specific hydrophobic properties. The significant differences in the structural properties may be closely related to the activation/inhibition mechanism of hTLR8.
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Affiliation(s)
- Shuheng Huang
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), Chongqing University, Chongqing, China.,College of Bioengineering, Chongqing University, Chongqing, China
| | - Hu Mei
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), Chongqing University, Chongqing, China.,College of Bioengineering, Chongqing University, Chongqing, China
| | - Duo Zhang
- College of Bioengineering, Chongqing University, Chongqing, China
| | - Tingting Shi
- College of Bioengineering, Chongqing University, Chongqing, China
| | - Linxin Chen
- College of Bioengineering, Chongqing University, Chongqing, China
| | - Zuyin Kuang
- College of Bioengineering, Chongqing University, Chongqing, China
| | - Yu Heng
- College of Bioengineering, Chongqing University, Chongqing, China
| | - Xianchao Pan
- College of Bioengineering, Chongqing University, Chongqing, China.,Department of Medicinal Chemistry, College of Pharmacy, Southwest Medical University, Luzhou, China
| | - Laichun Lu
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), Chongqing University, Chongqing, China.,College of Bioengineering, Chongqing University, Chongqing, China
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Vierbuchen T, Stein K, Heine H. RNA is taking its Toll: Impact of RNA-specific Toll-like receptors on health and disease. Allergy 2019; 74:223-235. [PMID: 30475385 DOI: 10.1111/all.13680] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 11/08/2018] [Accepted: 11/20/2018] [Indexed: 12/13/2022]
Abstract
RNA-sensing Toll-like receptors (TLRs) are often described as antiviral receptors of the innate immune system. However, the past decade has shown that the function and relevance of these receptors are far more complex. They were found to be essential for the detection of various bacterial, archaeal, and eukaryotic microorganisms and facilitate the discrimination between dead and living microbes. The cytokine and interferon response profile that is triggered has the potential to improve the efficacy of next-generation vaccines and may prevent the development of asthma and allergy. Nevertheless, the ability to recognize foreign RNA comes with a cost as also damaged host cells can release nucleic acids that might induce an inappropriate immune response. Thus, it is not surprising that RNA-sensing TLRs play a key role in various autoimmune diseases. However, promising new inhibitors and antagonists are on the horizon to improve their treatment.
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Affiliation(s)
- Tim Vierbuchen
- Division of Innate Immunity Research Center Borstel – Leibniz Lung Center Borstel Germany
| | - Karina Stein
- Division of Innate Immunity Research Center Borstel – Leibniz Lung Center Borstel Germany
- Airway Research Center North (ARCN) German Center for Lung Research (DZL) Borstel Germany
| | - Holger Heine
- Division of Innate Immunity Research Center Borstel – Leibniz Lung Center Borstel Germany
- Airway Research Center North (ARCN) German Center for Lung Research (DZL) Borstel Germany
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