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Xuan S, Ma Y, Zhou H, Gu S, Yao X, Zeng X. The implication of dendritic cells in lung diseases: Immunological role of toll-like receptor 4. Genes Dis 2024; 11:101007. [PMID: 39238498 PMCID: PMC11375267 DOI: 10.1016/j.gendis.2023.04.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 04/11/2023] [Accepted: 04/17/2023] [Indexed: 09/07/2024] Open
Abstract
The immune responses play a profound role in the progression of lung lesions in both infectious and non-infectious diseases. Dendritic cells, as the "frontline" immune cells responsible for antigen presentation, set up a bridge between innate and adaptive immunity in the course of these diseases. Among the receptors equipped in dendritic cells, Toll-like receptors are a group of specialized receptors as one type of pattern recognition receptors, capable of sensing environmental signals including invading pathogens and self-antigens. Toll-like receptor 4, a pivotal member of the Toll-like receptor family, was formerly recognized as a receptor sensitive to the outer membrane component lipopolysaccharide derived from Gram-negative bacteria, triggering the subsequent response. Moreover, its other essential roles in immune responses have drawn significant attention in the past decade. A better understanding of the implication of Toll-like receptor 4 in dendritic cells could contribute to the management of pulmonary diseases including pneumonia, pulmonary tuberculosis, asthma, acute lung injury, and lung cancer.
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Affiliation(s)
- Shurui Xuan
- Department of Pulmonary & Critical Care Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
- Department of Respiratory Medicine, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu 210006, China
| | - Yuan Ma
- Department of Pulmonary & Critical Care Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Honglei Zhou
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Shengwei Gu
- Department of Pulmonary & Critical Care Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Xin Yao
- Department of Pulmonary & Critical Care Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Xiaoning Zeng
- Department of Pulmonary & Critical Care Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
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2
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Fioretto L, Ziaco M, Mercogliano M, Gallo C, Nuzzo G, d'Ippolito G, Castiglia D, Fontana A, Manzo E. The Janus effect of colloidal self-assembly on the biological response of amphiphilic drugs. Pharmacol Res 2024; 208:107400. [PMID: 39251100 DOI: 10.1016/j.phrs.2024.107400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2024] [Revised: 08/26/2024] [Accepted: 09/03/2024] [Indexed: 09/11/2024]
Abstract
In aqueous environment amphiphilic molecules organize themselves into supramolecular structures deeply affecting the chemo-physical properties. Supramolecular assemby is also crucial in the pharmaceutical development of bioactive lipophilic molecules whose attitude to self-aggregate is a recognized factor affecting the in vivo pharmacokinetic, but can also play a crucial role in the interaction with the biological targets in in vitro tests. In aqueous solution, amphiphilic drugs exist in a complex equilibrium involving free monomers, oligomers and larger supramolecular aggregates held together by noncovalent bonds. In this review we focus our attention on the dual effect of drugs self-assembly, which can both reduce the availability of active compounds and create multivalent scaffolds, potentially improving binding affinity and avidity to cellular targets. We examine the effect of aggregation on different classes of amphiphatic molecules with significant biological activities, such as immunomodulatory, anti-tumor, antiviral, and antibiotic. Our purpose is to provide a comprehensive overview of how supramolecular chemistry influences the pharmacological and biological responses of amphiphilic molecules, emphasizing the need to consider these effects in early-stage drug development and in vitro testing. By elucidating these phenomena, this review aims to offer insights into optimizing drug design and formulation to overcome challenges posed by self-aggregation.
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Affiliation(s)
- Laura Fioretto
- CNR-Institute of Biomolecular Chemistry, Via Paolo Gaifami 18, Catania 95126, Italy
| | - Marcello Ziaco
- Bio-Organic Chemistry Unit, CNR-Institute of Biomolecular Chemistry, Via Campi Flegrei 34, 80078 Pozzuoli, Napoli, Italy
| | - Marcello Mercogliano
- Bio-Organic Chemistry Unit, CNR-Institute of Biomolecular Chemistry, Via Campi Flegrei 34, 80078 Pozzuoli, Napoli, Italy; University of Naples Federico II, Dept. of Chemical Science, Via Cinthia, Napoli 80126, Italy
| | - Carmela Gallo
- Bio-Organic Chemistry Unit, CNR-Institute of Biomolecular Chemistry, Via Campi Flegrei 34, 80078 Pozzuoli, Napoli, Italy
| | - Genoveffa Nuzzo
- Bio-Organic Chemistry Unit, CNR-Institute of Biomolecular Chemistry, Via Campi Flegrei 34, 80078 Pozzuoli, Napoli, Italy
| | - Giuliana d'Ippolito
- Bio-Organic Chemistry Unit, CNR-Institute of Biomolecular Chemistry, Via Campi Flegrei 34, 80078 Pozzuoli, Napoli, Italy
| | - Daniela Castiglia
- Bio-Organic Chemistry Unit, CNR-Institute of Biomolecular Chemistry, Via Campi Flegrei 34, 80078 Pozzuoli, Napoli, Italy
| | - Angelo Fontana
- Bio-Organic Chemistry Unit, CNR-Institute of Biomolecular Chemistry, Via Campi Flegrei 34, 80078 Pozzuoli, Napoli, Italy; University of Naples Federico II, Dept. of Biology, Via Cinthia, Napoli 80126, Italy.
| | - Emiliano Manzo
- Bio-Organic Chemistry Unit, CNR-Institute of Biomolecular Chemistry, Via Campi Flegrei 34, 80078 Pozzuoli, Napoli, Italy.
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3
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Tang X, Fang M, Cheng R, Niu J, Huang X, Xu K, Wang G, Sun Y, Liao Z, Zhang Z, Mwangi J, Lu Q, Wang A, Lv L, Liu C, Miao Y, Lai R. Transferrin Is Up-Regulated by Microbes and Acts as a Negative Regulator of Immunity to Induce Intestinal Immunotolerance. RESEARCH (WASHINGTON, D.C.) 2024; 7:0301. [PMID: 38274126 PMCID: PMC10809841 DOI: 10.34133/research.0301] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 12/26/2023] [Indexed: 01/27/2024]
Abstract
Cross-talks (e.g., host-driven iron withdrawal and microbial iron uptake between host gastrointestinal tract and commensal microbes) regulate immunotolerance and intestinal homeostasis. However, underlying mechanisms that regulate the cross-talks remain poorly understood. Here, we show that bacterial products up-regulate iron-transporter transferrin and transferrin acts as an immunosuppressor by interacting with cluster of differentiation 14 (CD14) to inhibit pattern recognition receptor (PRR) signaling and induce host immunotolerance. Decreased intestinal transferrin is found in germ-free mice and human patients with ulcerative colitis, which are characterized by impaired intestinal immunotolerance. Intestinal transferrin and host immunotolerance are returned to normal when germ-free mice get normal microbial commensalism, suggesting an association between microbial commensalism, transferrin, and host immunotolerance. Mouse colitis models show that transferrin shortage impairs host's tolerogenic responses, while its supplementation promotes immunotolerance. Designed peptide blocking transferrin-CD14 interaction inhibits immunosuppressive effects of transferrin. In monkeys with idiopathic chronic diarrhea, transferrin shows comparable or even better therapeutic effects than hydrocortisone. Our findings reveal that by up-regulating host transferrin to silence PRR signaling, commensal bacteria counteract immune activation induced by themselves to shape host immunity and contribute for intestinal tolerance.
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Affiliation(s)
- Xiaopeng Tang
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), and Sino-African Joint Research Center, New Cornerstone Science Institute, Kunming Institute of Zoology,
the Chinese Academy of Sciences, No.17 Longxin Road, Kunming, Yunnan, 650201, China
- School of Basic Medicine,
Qingdao University, Qingdao 266071, Shandong, China
| | - Mingqian Fang
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), and Sino-African Joint Research Center, New Cornerstone Science Institute, Kunming Institute of Zoology,
the Chinese Academy of Sciences, No.17 Longxin Road, Kunming, Yunnan, 650201, China
| | - Ruomei Cheng
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), and Sino-African Joint Research Center, New Cornerstone Science Institute, Kunming Institute of Zoology,
the Chinese Academy of Sciences, No.17 Longxin Road, Kunming, Yunnan, 650201, China
| | - Junkun Niu
- Department of Gastroenterology, First Affiliated Hospital of Kunming Medical University,
Yunnan Institute of Digestive Disease, Kunming 650032, Yunnan, China
- Yunnan Province Clinical Research Center for Digestive Diseases, Kunming 650032, Yunnan, China
| | - Xiaoshan Huang
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), and Sino-African Joint Research Center, New Cornerstone Science Institute, Kunming Institute of Zoology,
the Chinese Academy of Sciences, No.17 Longxin Road, Kunming, Yunnan, 650201, China
- Kunming College of Life Science,
University of Chinese Academy of Sciences, Kunming 650204, Yunnan, China
| | - Kuanhong Xu
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences,
University of Science and Technology of China, Hefei 230027, Anhui, China
| | - Gan Wang
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), and Sino-African Joint Research Center, New Cornerstone Science Institute, Kunming Institute of Zoology,
the Chinese Academy of Sciences, No.17 Longxin Road, Kunming, Yunnan, 650201, China
| | - Yang Sun
- Department of Gastroenterology, First Affiliated Hospital of Kunming Medical University,
Yunnan Institute of Digestive Disease, Kunming 650032, Yunnan, China
- Yunnan Province Clinical Research Center for Digestive Diseases, Kunming 650032, Yunnan, China
| | - Zhiyi Liao
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), and Sino-African Joint Research Center, New Cornerstone Science Institute, Kunming Institute of Zoology,
the Chinese Academy of Sciences, No.17 Longxin Road, Kunming, Yunnan, 650201, China
- Kunming College of Life Science,
University of Chinese Academy of Sciences, Kunming 650204, Yunnan, China
| | - Zhiye Zhang
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), and Sino-African Joint Research Center, New Cornerstone Science Institute, Kunming Institute of Zoology,
the Chinese Academy of Sciences, No.17 Longxin Road, Kunming, Yunnan, 650201, China
| | - James Mwangi
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), and Sino-African Joint Research Center, New Cornerstone Science Institute, Kunming Institute of Zoology,
the Chinese Academy of Sciences, No.17 Longxin Road, Kunming, Yunnan, 650201, China
- Kunming College of Life Science,
University of Chinese Academy of Sciences, Kunming 650204, Yunnan, China
| | - Qiumin Lu
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), and Sino-African Joint Research Center, New Cornerstone Science Institute, Kunming Institute of Zoology,
the Chinese Academy of Sciences, No.17 Longxin Road, Kunming, Yunnan, 650201, China
| | - Aili Wang
- Center for Evolution and Conservation Biology, Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, Guangdong, China
| | - Longbao Lv
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), and Sino-African Joint Research Center, New Cornerstone Science Institute, Kunming Institute of Zoology,
the Chinese Academy of Sciences, No.17 Longxin Road, Kunming, Yunnan, 650201, China
| | - Chao Liu
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), and Sino-African Joint Research Center, New Cornerstone Science Institute, Kunming Institute of Zoology,
the Chinese Academy of Sciences, No.17 Longxin Road, Kunming, Yunnan, 650201, China
| | - Yinglei Miao
- Department of Gastroenterology, First Affiliated Hospital of Kunming Medical University,
Yunnan Institute of Digestive Disease, Kunming 650032, Yunnan, China
- Yunnan Province Clinical Research Center for Digestive Diseases, Kunming 650032, Yunnan, China
| | - Ren Lai
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), and Sino-African Joint Research Center, New Cornerstone Science Institute, Kunming Institute of Zoology,
the Chinese Academy of Sciences, No.17 Longxin Road, Kunming, Yunnan, 650201, China
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4
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Zou H, Ben T, Wu P, Waterhouse GI, Chen Y. Effective anti-inflammatory phenolic compounds from dandelion: identification and mechanistic insights using UHPLC-ESI-MS/MS, fluorescence quenching and anisotropy, molecular docking and dynamics simulation. FOOD SCIENCE AND HUMAN WELLNESS 2023. [DOI: 10.1016/j.fshw.2023.03.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2023]
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5
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Sidor K, Skirecki T. A Bittersweet Kiss of Gram-Negative Bacteria: The Role of ADP-Heptose in the Pathogenesis of Infection. Microorganisms 2023; 11:1316. [PMID: 37317291 DOI: 10.3390/microorganisms11051316] [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: 02/27/2023] [Revised: 05/10/2023] [Accepted: 05/15/2023] [Indexed: 06/16/2023] Open
Abstract
Due to the global crisis caused by the dramatic rise of drug resistance among Gram-negative bacteria, there is an urgent need for a thorough understanding of the pathogenesis of infections of such an etiology. In light of the limited availability of new antibiotics, therapies aimed at host-pathogen interactions emerge as potential treatment modalities. Thus, understanding the mechanism of pathogen recognition by the host and immune evasion appear to be the key scientific issues. Until recently, lipopolysaccharide (LPS) was recognized as a major pathogen-associated molecular pattern (PAMP) of Gram-negative bacteria. However, recently, ADP-L-glycero-β-D-manno-heptose (ADP-heptose), an intermediate carbohydrate metabolite of the LPS biosynthesis pathway, was discovered to activate the hosts' innate immunity. Therefore, ADP-heptose is regarded as a novel PAMP of Gram-negative bacteria that is recognized by the cytosolic alpha kinase-1 (ALPK1) protein. The conservative nature of this molecule makes it an intriguing player in host-pathogen interactions, especially in the context of changes in LPS structure or even in its loss by certain resistant pathogens. Here, we present the ADP-heptose metabolism, outline the mechanisms of its recognition and the activation of its immunity, and summarize the role of ADP-heptose in the pathogenesis of infection. Finally, we hypothesize about the routes of the entry of this sugar into cytosol and point to emerging questions that require further research.
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Affiliation(s)
- Karolina Sidor
- Department of Translational Immunology and Experimental Intensive Care, Centre of Postgraduate Medical Education, Marymoncka 99/103, 01-813 Warsaw, Poland
| | - Tomasz Skirecki
- Department of Translational Immunology and Experimental Intensive Care, Centre of Postgraduate Medical Education, Marymoncka 99/103, 01-813 Warsaw, Poland
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6
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Kotlyarov S, Kotlyarova A. The Importance of the Plasma Membrane in Atherogenesis. MEMBRANES 2022; 12:1036. [PMID: 36363591 PMCID: PMC9698587 DOI: 10.3390/membranes12111036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 10/20/2022] [Accepted: 10/21/2022] [Indexed: 06/16/2023]
Abstract
Atherosclerotic cardiovascular diseases are an important medical problem due to their high prevalence, impact on quality of life and prognosis. The pathogenesis of atherosclerosis is an urgent medical and social problem, the solution of which may improve the quality of diagnosis and treatment of patients. Atherosclerosis is a complex chain of events, which proceeds over many years and in which many cells in the bloodstream and the vascular wall are involved. A growing body of evidence suggests that there are complex, closely linked molecular mechanisms that occur in the plasma membranes of cells involved in atherogenesis. Lipid transport, innate immune system receptor function, and hemodynamic regulation are linked to plasma membranes and their biophysical properties. A better understanding of these interrelationships will improve diagnostic quality and treatment efficacy.
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Affiliation(s)
- Stanislav Kotlyarov
- Department of Nursing, Ryazan State Medical University, 390026 Ryazan, Russia
| | - Anna Kotlyarova
- Department of Pharmacy Management and Economics, Ryazan State Medical University, 390026 Ryazan, Russia
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7
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Gauthier AE, Rotjan RD, Kagan JC. Lipopolysaccharide detection by the innate immune system may be an uncommon defence strategy used in nature. Open Biol 2022; 12:220146. [PMID: 36196535 PMCID: PMC9533005 DOI: 10.1098/rsob.220146] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 09/09/2022] [Indexed: 11/12/2022] Open
Abstract
Since the publication of the Janeway's Pattern Recognition hypothesis in 1989, study of pathogen-associated molecular patterns (PAMPs) and their immuno-stimulatory activities has accelerated. Most studies in this area have been conducted in model organisms, which leaves many open questions about the universality of PAMP biology across living systems. Mammals have evolved multiple proteins that operate as receptors for the PAMP lipopolysaccharide (LPS) from Gram-negative bacteria, but LPS is not immuno-stimulatory in all eukaryotes. In this review, we examine the history of LPS as a PAMP in mammals, recent data on LPS structure and its ability to activate mammalian innate immune receptors, and how these activities compare across commonly studied eukaryotes. We discuss why LPS may have evolved to be immuno-stimulatory in some eukaryotes but not others and propose two hypotheses about the evolution of PAMP structure based on the ecology and environmental context of the organism in question. Understanding PAMP structures and stimulatory mechanisms across multi-cellular life will provide insights into the evolutionary origins of innate immunity and may lead to the discovery of new PAMP variations of scientific and therapeutic interest.
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Affiliation(s)
- Anna E. Gauthier
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
- Program in Virology, Harvard Medical School, Boston, MA, USA
| | - Randi D. Rotjan
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, USA
| | - Jonathan C. Kagan
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
- Harvard Medical School, and Boston Children's Hospital, Division of Immunology, Division of Gastroenterology, USA
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8
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Peng H, Wang J, Song X, Huang J, Hua H, Wang F, Xu Z, Ma J, Gao J, Zhao J, Nong A, Huang D, Liang B. PHLDA1 Suppresses TLR4-Triggered Proinflammatory Cytokine Production by Interaction With Tollip. Front Immunol 2022; 13:731500. [PMID: 35237256 PMCID: PMC8882599 DOI: 10.3389/fimmu.2022.731500] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 01/17/2022] [Indexed: 02/05/2023] Open
Abstract
Pleckstrin homology-like domain, family A, member 1 (PHLDA1) has been reported to be expressed in many mammalian tissues and cells. However, the functions and exact mechanisms of PHLDA1 remain unclear. In this study, we found that PHLDA1 expression was significantly altered in macrophages after exposure to lipopolysaccharide (LPS) in vitro, suggesting that PHLDA1 may be involved in the regulation of TLR4 signaling pathway activated by LPS. PHLDA1 attenuated the production of LPS-stimulated proinflammatory cytokines (TNF-α, IL-6, and IL-1β). Further research showed that the phosphorylation levels of some important signal molecules in TLR4/MyD88-mediated MAPK and NF-κB signaling pathways were reduced by PHLDA1, which in turn impaired the transcription factors NF-κB and AP1 nuclear translocation and their responsive element activities. Furthermore, we found that PHLDA1 repressed LPS-induced proinflammatory cytokine production via binding to Tollip which restrained TLR4 signaling pathway. A mouse model of endotoxemia was established to confirm the above similar results. In brief, our findings demonstrate that PHLDA1 is a negative regulator of LPS-induced proinflammatory cytokine production by Tollip, suggesting that PHLDA1 plays an anti-inflammatory role through inhibiting the TLR4/MyD88 signaling pathway with the help of Tollip. PHLDA1 may be a novel therapeutic target in treating endotoxemia.
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Affiliation(s)
- Hui Peng
- Department of Cell Biology and Genetics, Key Laboratory of Molecular Biology in High Cancer Incidence Coastal Chao Shan Area of Guang Dong Higher Education Institutes, Shantou University Medical College, Shantou, China
- Department of Clinical Laboratory, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, China
| | - Juping Wang
- Department of Pathophysiology, School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, China
| | - Xuhong Song
- Department of Cell Biology and Genetics, Key Laboratory of Molecular Biology in High Cancer Incidence Coastal Chao Shan Area of Guang Dong Higher Education Institutes, Shantou University Medical College, Shantou, China
| | - Jiangni Huang
- Department of Pathophysiology, School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, China
| | - Haoming Hua
- Department of Pathophysiology, School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, China
| | - Fanlu Wang
- Department of Pathophysiology, School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, China
| | - Ziyun Xu
- Department of Pathophysiology, School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, China
| | - Jing Ma
- Department of Pathophysiology, School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, China
| | - Jie Gao
- Department of Pathophysiology, School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, China
| | - Jing Zhao
- Department of Pathophysiology, School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, China
| | - Anna Nong
- Department of Pathophysiology, School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, China
| | - Dongyang Huang
- Department of Cell Biology and Genetics, Key Laboratory of Molecular Biology in High Cancer Incidence Coastal Chao Shan Area of Guang Dong Higher Education Institutes, Shantou University Medical College, Shantou, China
- *Correspondence: Bin Liang, ; Dongyang Huang,
| | - Bin Liang
- Department of Cell Biology and Genetics, Key Laboratory of Molecular Biology in High Cancer Incidence Coastal Chao Shan Area of Guang Dong Higher Education Institutes, Shantou University Medical College, Shantou, China
- *Correspondence: Bin Liang, ; Dongyang Huang,
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Bu R, Deng X, Cao Y, Jin J, Mai B, Meng K, Liu X, Chi JC, Zhang Y, Qiu F. Effect of different sample treatment methods on Low Endotoxin Recovery Phenomenon. J Microbiol Methods 2021; 186:106241. [PMID: 33992679 DOI: 10.1016/j.mimet.2021.106241] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/12/2021] [Accepted: 05/12/2021] [Indexed: 12/17/2022]
Abstract
Endotoxin is a kind of lipopolysaccharide that exits on the cell wall of Gram-negative bacteria. It can cause fever, shock or even death when is delivered into human body. So, it is necessary to control the endotoxin contamination for biopharmaceutical products that are mainly administered by intravenous route. Limulus Amebocyte Lysate (LAL)-based tests are usually used to detect endotoxin content in biologics formulations. However, an undesirable phenomenon called "Low Endotoxin Recovery (LER)" often occurs in formulation buffers that usually contain chelating component, such as sodium citrate, and amphiphilic surfactant, such as Tween-20. The occurrence of this LER phenomenon may interfere with endotoxin detection and cause false negative results. In this study, we compared the effect of different sample treatment methods on endotoxin detection and found that the LER phenomenon was better controlled under the conditions of low pH (pH = 5.0), low temperature (2-8 °C) and in the presence of divalent cations in the solution. In addition, although the endotoxin activity was found to have decreased due to LER phenomenon, the particle size distribution of endotoxin determined by dynamic light scattering (DLS) in LER solution did not change obviously, which is different from previous hypothesis about LER phenomenon in literature that the particle size of endotoxin aggregates would decrease under LER conditions. These findings provide some insights into different sample treatment methods for endotoxin detection and give a better understanding and solution on minimizing the LER phenomenon.
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Affiliation(s)
- Ruixuan Bu
- Department of Process Development, BeiGene Guangzhou Biologics Manufacturing Co., Ltd., Guangzhou, China
| | - Xinren Deng
- Department of Process Development, BeiGene Guangzhou Biologics Manufacturing Co., Ltd., Guangzhou, China
| | - Yuan Cao
- Department of Process Development, BeiGene Guangzhou Biologics Manufacturing Co., Ltd., Guangzhou, China
| | - Jiayi Jin
- Department of Process Development, BeiGene Guangzhou Biologics Manufacturing Co., Ltd., Guangzhou, China
| | - Binliang Mai
- Department of Process Development, BeiGene Guangzhou Biologics Manufacturing Co., Ltd., Guangzhou, China
| | - Ke Meng
- Department of Process Development, BeiGene Guangzhou Biologics Manufacturing Co., Ltd., Guangzhou, China
| | - Xiaohui Liu
- Department of Process Development, BeiGene Guangzhou Biologics Manufacturing Co., Ltd., Guangzhou, China
| | - Jen-Chih Chi
- Department of Process Development, BeiGene Guangzhou Biologics Manufacturing Co., Ltd., Guangzhou, China
| | - Yujie Zhang
- Department of Process Development, BeiGene Guangzhou Biologics Manufacturing Co., Ltd., Guangzhou, China.
| | - Frank Qiu
- Department of Process Development, BeiGene Guangzhou Biologics Manufacturing Co., Ltd., Guangzhou, China
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10
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Fukuda K. Corneal fibroblasts: Function and markers. Exp Eye Res 2020; 200:108229. [PMID: 32919991 DOI: 10.1016/j.exer.2020.108229] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 09/01/2020] [Accepted: 09/03/2020] [Indexed: 02/06/2023]
Abstract
Corneal stromal keratocytes contribute to the maintenance of corneal transparency and shape by synthesizing and degrading extracellular matrix. They are quiescent in the healthy cornea, but they become activated in response to insults from the external environment that breach the corneal epithelium, with such activation being associated with phenotypic transformation into fibroblasts. Corneal fibroblasts (activated keratocytes) act as sentinel cells to sense various external stimuli-including damage-associated molecular patterns derived from injured cells, pathogen-associated molecular patterns of infectious microorganisms, and inflammatory mediators such as cytokines-under pathological conditions such as trauma, infection, and allergy. The expression of various chemokines and adhesion molecules by corneal fibroblasts determines the selective recruitment and activation of inflammatory cells in a manner dependent on the type of insult. In infectious keratitis, the interaction of corneal fibroblasts with various components of microbes and with cytokines derived from infiltrated inflammatory cells results in excessive degradation of stromal collagen and consequent corneal ulceration. Corneal fibroblasts distinguish between type 1 and type 2 inflammation through recognition of corresponding cytokines, with their activation by type 2 cytokines contributing to the pathogenesis of corneal lesions in severe ocular allergic diseases. Pharmacological targeting of corneal fibroblast function is thus a potential novel therapeutic approach to prevention of excessive corneal stromal inflammation, damage, and scarring.
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Affiliation(s)
- Ken Fukuda
- Department of Ophthalmology and Visual Science, Kochi Medical School, Kochi University, Oko-cho, Nankoku City, Kochi, 783-8505, Japan.
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11
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Huang M, Li Y, Tian T, Wang K, Wang Y, Yan W, Yang H. Knockdown of TLR4 Represses the Paraquat-Induced Neuroinflammation and Microglial M1 Polarization. Neurotox Res 2020; 38:741-750. [PMID: 32734565 DOI: 10.1007/s12640-020-00261-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 07/03/2020] [Accepted: 07/22/2020] [Indexed: 01/19/2023]
Abstract
Paraquat (PQ) is associated with multiple nervous system disorders including Parkinson's disease. Despite the evidence that PQ could induce inflammatory responses in the central nervous system and largely contribute to neurotoxicity, the mechanisms of PQ-induced neuroinflammation are not yet fully understood. Toll-like receptor 4 (TLR4) could recognize various pathogens and initiate inflammation processes. Therefore, we investigated the role of TLR4 in PQ-induced neuroinflammation by using murine microglial immortalized BV-2 cell line. Normal microglia and TLR4-knockdown microglia were treated with PQ to evaluate signal transduction molecular expression, inflammatory responses, and microglial functions. Compared with normal microglia, PQ-induced production of pro-inflammatory cytokines was significantly reduced in TLR4-knockdown microglia. Levels of M1 markers were decreased, while levels of M2 markers were increased upon PQ exposure, confirming that TLR4 depletion inhibited the microglial M1 polarization. Besides, the migration and phagocytosis capability reduced by PQ were to some extent recovered in TLR4-knockdown microglia. Taken together, our results suggested that TLR4 mediated the neuroinflammatory responses in microglia and the depletion of TLR4 protects against PQ neurotoxicity.
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Affiliation(s)
- Min Huang
- The Department of Occupational and Environmental Health, School of Public Health and Management, Ningxia Medical University, 750004, 1160 Shengli Street, Xingqing District, Yinchuan, 750004, China
| | - Yingying Li
- The Department of Occupational and Environmental Health, School of Public Health and Management, Ningxia Medical University, 750004, 1160 Shengli Street, Xingqing District, Yinchuan, 750004, China
| | - Tian Tian
- The Department of Occupational and Environmental Health, School of Public Health and Management, Ningxia Medical University, 750004, 1160 Shengli Street, Xingqing District, Yinchuan, 750004, China
| | - Kai Wang
- The Department of Occupational and Environmental Health, School of Public Health and Management, Ningxia Medical University, 750004, 1160 Shengli Street, Xingqing District, Yinchuan, 750004, China
| | - Yifan Wang
- The Department of Occupational and Environmental Health, School of Public Health and Management, Ningxia Medical University, 750004, 1160 Shengli Street, Xingqing District, Yinchuan, 750004, China
| | - Weiguang Yan
- The Department of Occupational and Environmental Health, School of Public Health and Management, Ningxia Medical University, 750004, 1160 Shengli Street, Xingqing District, Yinchuan, 750004, China
| | - Huifang Yang
- The Department of Occupational and Environmental Health, School of Public Health and Management, Ningxia Medical University, 750004, 1160 Shengli Street, Xingqing District, Yinchuan, 750004, China.
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12
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Human Toll-Like Receptor 4 (hTLR4): Structural and functional dynamics in cancer. Int J Biol Macromol 2019; 122:425-451. [DOI: 10.1016/j.ijbiomac.2018.10.142] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 10/10/2018] [Accepted: 10/18/2018] [Indexed: 12/23/2022]
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13
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Dickinson SE, Wondrak GT. TLR4-directed Molecular Strategies Targeting Skin Photodamage and Carcinogenesis. Curr Med Chem 2019; 25:5487-5502. [DOI: 10.2174/0929867324666170828125328] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 06/30/2017] [Accepted: 06/30/2017] [Indexed: 01/16/2023]
Abstract
Background:
Exposure to solar ultraviolet (UV) radiation is a causative factor in
skin photodamage and carcinogenesis, and inflammatory dysregulation is a key mechanism
underlying detrimental effects of acute and chronic UV exposure. The health and economic
burden of skin cancer treatment is substantial, creating an increasingly urgent need for the development
of improved molecular strategies for photoprotection and photochemoprevention.
Methods:
A structured search of bibliographic databases for peer-reviewed research literature
revealed 139 articles including our own that are presented and critically evaluated in this
TLR4-directed review.
Objective:
To understand the molecular role of Toll-like receptor 4 (TLR4) as a key regulator
of skin anti-microbial defense, wound healing, and cutaneous tumorigenic inflammation. The
specific focus of this review is on recent published evidence suggesting that TLR4 represents
a novel molecular target for skin photoprotection and cancer photochemoprevention.
Results:
Cumulative experimental evidence indicates that pharmacological and genetic antagonism
of TLR4 suppresses UV-induced inflammatory signaling involving the attenuation
of cutaneous NF-κB and AP-1 stress signaling observable in vitro and in vivo. TLR4-directed
small molecule pharmacological antagonists [including eritoran, (+)-naloxone, ST2825, and
resatorvid] have now been identified as a novel class of molecular therapeutics. TLR4 antagonists
are in various stages of preclinical and clinical development for the modulation of
dysregulated TLR4-dependent inflammatory signaling that may also contribute to skin photodamage
and photocarcinogenesis in human populations.
Conclusion:
Future research should explore the skin photoprotective and photochemopreventive
efficacy of topical TLR4 antagonism if employed in conjunction with other molecular
strategies including sunscreens.
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Affiliation(s)
- Sally E. Dickinson
- Department of Pharmacology, College of Medicine and The University of Arizona Cancer Center, University of Arizona, Tucson, AZ 85724, United States
| | - Georg T. Wondrak
- Department of Pharmacology and Toxicology, College of Pharmacy and The University of Arizona Cancer Center, University of Arizona, Tucson, AZ 85724, United States
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14
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Abstract
In humans and other mammals, recognition of endotoxins—abundant surface lipopolysaccharides (LPS) of Gram-negative bacteria—provides a potent stimulus for induction of inflammation and mobilization of host defenses. The structurally unique lipid A region of LPS is the principal determinant of this pro-inflammatory activity. This region of LPS is normally buried within the bacterial outer membrane and aggregates of purified LPS, making even more remarkable its picomolar potency and the ability of discrete variations in lipid A structure to markedly alter the pro-inflammatory activity of LPS. Two recognition systems—MD-2/TLR4 and “LPS-sensing” cytosolic caspases—together confer LPS responsiveness at the host cell surface, within endosomes, and at sites physically accessible to the cytosol. Understanding how the lipid A of LPS is delivered and recognized at these diverse sites is crucial to understanding how the magnitude and character of the inflammatory responses are regulated.
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Affiliation(s)
- Jerrold Weiss
- Inflammation Program and Departments of Internal Medicine and Microbiology, University of Iowa, Iowa City, Iowa, USA.,Veterans Affairs Medical Center, Iowa City, Iowa, USA
| | - Jason Barker
- Inflammation Program and Departments of Internal Medicine and Microbiology, University of Iowa, Iowa City, Iowa, USA.,Veterans Affairs Medical Center, Iowa City, Iowa, USA
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15
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Blohm-Mangone K, Burkett NB, Tahsin S, Myrdal PB, Aodah A, Ho B, Janda J, McComas M, Saboda K, Roe DJ, Dong Z, Bode AM, Petricoin EF, Calvert VS, Curiel-Lewandrowski C, Alberts DS, Wondrak GT, Dickinson SE. Pharmacological TLR4 Antagonism Using Topical Resatorvid Blocks Solar UV-Induced Skin Tumorigenesis in SKH-1 Mice. Cancer Prev Res (Phila) 2018; 11:265-278. [PMID: 29437671 DOI: 10.1158/1940-6207.capr-17-0349] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 01/02/2018] [Accepted: 01/19/2018] [Indexed: 02/06/2023]
Abstract
An urgent need exists for the development of more efficacious molecular strategies targeting nonmelanoma skin cancer (NMSC), the most common malignancy worldwide. Inflammatory signaling downstream of Toll-like receptor 4 (TLR4) has been implicated in several forms of tumorigenesis, yet its role in solar UV-induced skin carcinogenesis remains undefined. We have previously shown in keratinocyte cell culture and SKH-1 mouse epidermis that topical application of the specific TLR4 antagonist resatorvid (TAK-242) blocks acute UV-induced AP-1 and NF-κB signaling, associated with downregulation of inflammatory mediators and MAP kinase phosphorylation. We therefore explored TLR4 as a novel target for chemoprevention of UV-induced NMSC. We selected the clinical TLR4 antagonist resatorvid based upon target specificity, potency, and physicochemical properties. Here, we confirm using ex vivo permeability assays that topical resatorvid can be effectively delivered to skin, and using in vivo studies that topical resatorvid can block UV-induced AP-1 activation in mouse epidermis. We also report that in a UV-induced skin tumorigenesis model, topical resatorvid displays potent photochemopreventive activity, significantly suppressing tumor area and multiplicity. Tumors harvested from resatorvid-treated mice display reduced activity of UV-associated signaling pathways and a corresponding increase in apoptosis compared with tumors from control animals. Further mechanistic insight on resatorvid-based photochemoprevention was obtained from unsupervised hierarchical clustering analysis of protein readouts via reverse-phase protein microarray revealing a significant attenuation of key UV-induced proteomic changes by resatorvid in chronically treated high-risk SKH-1 skin prior to tumorigenesis. Taken together, our data identify TLR4 as a novel molecular target for topical photochemoprevention of NMSC. Cancer Prev Res; 11(5); 265-78. ©2018 AACRSee related editorial by Sfanos, p. 251.
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Affiliation(s)
| | | | - Shekha Tahsin
- The University of Arizona Cancer Center, Tucson, Arizona
| | - Paul B Myrdal
- Department of Pharmacy Practice and Science, The University of Arizona, Tucson, Arizona
| | - Alhassan Aodah
- Department of Pharmacy Practice and Science, The University of Arizona, Tucson, Arizona.,The National Center for Pharmaceutical Technology, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Brenda Ho
- The University of Arizona Cancer Center, Tucson, Arizona
| | - Jaroslav Janda
- The University of Arizona Cancer Center, Tucson, Arizona
| | | | | | - Denise J Roe
- The University of Arizona Cancer Center, Tucson, Arizona.,Mel and Enid Zuckerman College of Public Health, The University of Arizona, Tucson, Arizona
| | - Zigang Dong
- Department of Molecular Medicine and Biopharmaceutical Sciences, The Hormel Institute, The University of Minnesota, Austin, Minnesota
| | - Ann M Bode
- Department of Molecular Medicine and Biopharmaceutical Sciences, The Hormel Institute, The University of Minnesota, Austin, Minnesota
| | - Emanuel F Petricoin
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, Virginia
| | - Valerie S Calvert
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, Virginia
| | - Clara Curiel-Lewandrowski
- The University of Arizona Cancer Center, Tucson, Arizona.,Department of Medicine, The University of Arizona, Tucson, Arizona
| | - David S Alberts
- The University of Arizona Cancer Center, Tucson, Arizona.,Department of Medicine, The University of Arizona, Tucson, Arizona
| | - Georg T Wondrak
- The University of Arizona Cancer Center, Tucson, Arizona.,Department of Pharmacology and Toxicology, The University of Arizona, Tucson, Arizona
| | - Sally E Dickinson
- The University of Arizona Cancer Center, Tucson, Arizona. .,Department of Pharmacology, The University of Arizona, Tucson, Arizona
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16
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Recent advances on Toll-like receptor 4 modulation: new therapeutic perspectives. Future Med Chem 2018; 10:461-476. [PMID: 29380635 DOI: 10.4155/fmc-2017-0172] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Activation or inhibition of TLR4 by small molecules will provide in the next few years a new generation of therapeutics. TLR4 stimulation (agonism) by high-affinity ligands mimicking lipid A gave vaccine adjuvants with improved specificity and efficacy that have been licensed and entered into the market. TLR4 inhibition (antagonism) prevents cytokine production at a very early stage; this is in principle a more efficient method to block inflammatory diseases compared to cytokines neutralization by antibodies. Advances in TLR4 modulation by drug-like small molecules achieved in the last years are reviewed. Recently discovered TLR4 agonists and antagonists of natural and synthetic origin are presented, and their mechanism of action and structure-activity relationship are discussed.
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17
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Biophysical Analysis of Lipopolysaccharide Formulations for an Understanding of the Low Endotoxin Recovery (LER) Phenomenon. Int J Mol Sci 2017; 18:ijms18122737. [PMID: 29258200 PMCID: PMC5751338 DOI: 10.3390/ijms18122737] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 12/11/2017] [Accepted: 12/13/2017] [Indexed: 12/26/2022] Open
Abstract
Lipopolysaccharides (LPS, endotoxin) are complex and indispensable components of the outer membrane of most Gram-negative bacteria. They represent stimuli for many biological effects with pathophysiological character. Recombinant therapeutic proteins that are manufactured using biotechnological processes are prone to LPS contaminations due to their ubiquitous occurrence. The maximum endotoxin load of recombinant therapeutic proteins must be below the pyrogenic threshold. Certain matrices that are commonly used for recombinant therapeutic proteins show a phenomenon called “Low Endotoxin Recovery (LER)”. LER is defined as the loss of detectable endotoxin activity over time using compendial Limulus amebocyte lysate (LAL) assays when undiluted products are spiked with known amount of endotoxin standards. Because LER poses potential risks that endotoxin contaminations in products may be underestimated or undetected by the LAL assay, the United States (U.S.) Food and Drug Administration’s (FDA’s) Center for Drug Evaluation and Research (CDER) has recently started requesting that companies conduct endotoxin spike/hold recovery studies to determine whether a given biological product causes LER. Here, we have performed an analysis of different LPS preparations with relevant detergents studying their acyl chain phase transition, their aggregate structures, their size distributions, and binding affinity with a particular anti-endotoxin peptide, and correlating it with the respective data in the macrophage activation test. In this way, we have worked out biophysical parameters that are important for an understanding of LER.
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18
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Sobocińska J, Roszczenko-Jasińska P, Zaręba-Kozioł M, Hromada-Judycka A, Matveichuk OV, Traczyk G, Łukasiuk K, Kwiatkowska K. Lipopolysaccharide Upregulates Palmitoylated Enzymes of the Phosphatidylinositol Cycle: An Insight from Proteomic Studies. Mol Cell Proteomics 2017; 17:233-254. [PMID: 29217618 DOI: 10.1074/mcp.ra117.000050] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Indexed: 12/28/2022] Open
Abstract
Lipopolysaccharide (LPS) is a component of the outer membrane of Gram-negative bacteria that induces strong proinflammatory reactions of mammals. These processes are triggered upon sequential binding of LPS to CD14, a GPI-linked plasma membrane raft protein, and to the TLR4/MD2 receptor complex. We have found earlier that upon LPS binding, CD14 triggers generation of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2], a lipid controlling subsequent proinflammatory cytokine production. Here we show that stimulation of RAW264 macrophage-like cells with LPS induces global changes of the level of fatty-acylated, most likely palmitoylated, proteins. Among the acylated proteins that were up-regulated in those conditions were several enzymes of the phosphatidylinositol cycle. Global profiling of acylated proteins was performed by metabolic labeling of RAW264 cells with 17ODYA, an analogue of palmitic acid functionalized with an alkyne group, followed by detection and enrichment of labeled proteins using biotin-azide/streptavidin and their identification with mass spectrometry. This proteomic approach revealed that 154 fatty-acylated proteins were up-regulated, 186 downregulated, and 306 not affected in cells stimulated with 100 ng/ml LPS for 60 min. The acylated proteins affected by LPS were involved in diverse biological functions, as found by Ingenuity Pathway Analysis. Detailed studies of 17ODYA-labeled and immunoprecipitated proteins revealed that LPS induces S-palmitoylation, hence activation, of type II phosphatidylinositol 4-kinase (PI4KII) β, which phosphorylates phosphatidylinositol to phosphatidylinositol 4-monophosphate, a PI(4,5)P2 precursor. Silencing of PI4KIIβ and PI4KIIα inhibited LPS-induced expression and production of proinflammatory cytokines, especially in the TRIF-dependent signaling pathway of TLR4. Reciprocally, this LPS-induced signaling pathway was significantly enhanced after overexpression of PI4KIIβ or PI4KIIα; this was dependent on palmitoylation of the kinases. However, the S-palmitoylation of PI4KIIα, hence its activity, was constitutive in RAW264 cells. Taken together the data indicate that LPS triggers S-palmitoylation and activation of PI4KIIβ, which generates PI(4)P involved in signaling pathways controlling production of proinflammatory cytokines.
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Affiliation(s)
- Justyna Sobocińska
- From the ‡Laboratory of Molecular Membrane Biology, Department of Cell Biology
| | | | - Monika Zaręba-Kozioł
- §Laboratory of Cell Biophysics, Department of Molecular and Cellular Neurobiology
| | | | - Orest V Matveichuk
- From the ‡Laboratory of Molecular Membrane Biology, Department of Cell Biology
| | - Gabriela Traczyk
- From the ‡Laboratory of Molecular Membrane Biology, Department of Cell Biology
| | - Katarzyna Łukasiuk
- ¶Laboratory of Epileptogenesis, Department of Neurophysiology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland
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19
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TLR4 Signaling Pathway Modulators as Potential Therapeutics in Inflammation and Sepsis. Vaccines (Basel) 2017; 5:vaccines5040034. [PMID: 28976923 PMCID: PMC5748601 DOI: 10.3390/vaccines5040034] [Citation(s) in RCA: 381] [Impact Index Per Article: 54.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 09/29/2017] [Accepted: 10/01/2017] [Indexed: 02/06/2023] Open
Abstract
Toll-Like Receptor 4 (TLR4) signal pathway plays an important role in initiating the innate immune response and its activation by bacterial endotoxin is responsible for chronic and acute inflammatory disorders that are becoming more and more frequent in developed countries. Modulation of the TLR4 pathway is a potential strategy to specifically target these pathologies. Among the diseases caused by TLR4 abnormal activation by bacterial endotoxin, sepsis is the most dangerous one because it is a life-threatening acute system inflammatory condition that still lacks specific pharmacological treatment. Here, we review molecules at a preclinical or clinical phase of development, that are active in inhibiting the TLR4-MyD88 and TLR4-TRIF pathways in animal models. These are low-molecular weight compounds of natural and synthetic origin that can be considered leads for drug development. The results of in vivo studies in the sepsis model and the mechanisms of action of drug leads are presented and critically discussed, evidencing the differences in treatment results from rodents to humans.
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20
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Corneal Fibroblasts as Sentinel Cells and Local Immune Modulators in Infectious Keratitis. Int J Mol Sci 2017; 18:ijms18091831. [PMID: 28832498 PMCID: PMC5618480 DOI: 10.3390/ijms18091831] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 08/21/2017] [Accepted: 08/21/2017] [Indexed: 01/13/2023] Open
Abstract
The cornea serves as a barrier to protect the eye against external insults including microbial pathogens and antigens. Bacterial infection of the cornea often results in corneal melting and scarring that can lead to severe visual impairment. Not only live bacteria but also their components such as lipopolysaccharide (LPS) of Gram-negative bacteria contribute to the development of inflammation and subsequent corneal damage in infectious keratitis. We describe the important role played by corneal stromal fibroblasts (activated keratocytes) as sentinel cells, immune modulators, and effector cells in infectious keratitis. Corneal fibroblasts sense bacterial infection through Toll-like receptor (TLR)–mediated detection of a complex of LPS with soluble cluster of differentiation 14 (CD14) and LPS binding protein present in tear fluid. The cells then initiate innate immune responses including the expression of chemokines and adhesion molecules that promote the recruitment of inflammatory cells necessary for elimination of the infecting bacteria. Infiltrated neutrophils are activated by corneal stromal collagen and release mediators that stimulate the production of pro–matrix metalloproteinases by corneal fibroblasts. Elastase produced by Pseudomonas aeruginosa (P. aeruginosa) activates these released metalloproteinases, resulting in the degradation of stromal collagen. The modulation of corneal fibroblast activation and of the interaction of these cells with inflammatory cells and bacteria is thus important to minimize corneal scarring during treatment of infectious keratitis. Pharmacological agents that are able to restrain such activities of corneal fibroblasts without allowing bacterial growth represent a potential novel treatment option for prevention of excessive scarring and tissue destruction in the cornea.
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21
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Johswich K. Innate immune recognition and inflammation in Neisseria meningitidis infection. Pathog Dis 2017; 75:3059204. [PMID: 28334203 DOI: 10.1093/femspd/ftx022] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 02/23/2017] [Indexed: 01/01/2023] Open
Abstract
Neisseria meningitidis (Nme) can cause meningitis and sepsis, diseases which are characterised by an overwhelming inflammatory response. Inflammation is triggered by host pattern recognition receptors (PRRs) which are activated by pathogen-associated molecular patterns (PAMPs). Nme contains multiple PAMPs including lipooligosaccharide, peptidoglycan, proteins and metabolites. Various classes of PRRs including Toll-like receptors, NOD-like receptors, C-type lectins, scavenger receptors, pentraxins and others are expressed by the host to respond to any given microbe. While Toll-like receptors and NOD-like receptors are pivotal in triggering inflammation, other PRRs act as modulators of inflammation or aid in functional antimicrobial responses such as phagocytosis or complement activation. This review aims to give an overview of the various Nme PAMPs reported to date, the PRRs they activate and their implications during the inflammatory response to infection.
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22
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Hoppe Parr KA, Hađina S, Kilburg-Basnyat B, Wang Y, Chavez D, Thorne PS, Weiss JP. Modification of sample processing for the Limulus amebocyte lysate assay enhances detection of inflammogenic endotoxin in intact bacteria and organic dust. Innate Immun 2017; 23:307-318. [PMID: 28359219 PMCID: PMC5814115 DOI: 10.1177/1753425917694084] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The pro-inflammatory potency and causal relationship with asthma of inhaled endotoxins have underscored the importance of accurately assessing the endotoxin content of organic dusts. The Limulus amebocyte lysate (LAL) assay has emerged as the preferred assay, but its ability to measure endotoxin in intact bacteria and organic dusts with similar sensitivity as purified endotoxin is unknown. We used metabolically radiolabeled Neisseria meningitidis and both rough and smooth Escherichia coli to compare dose-dependent activation in the LAL with purified endotoxin from these bacteria and shed outer membrane (OM) blebs. Labeled [14C]-3-OH-fatty acids were used to quantify the endotoxin content of the samples. Purified meningococcal and E. coli endotoxins and OM blebs displayed similar specific activity in the LAL assay to the purified LPS standard. In contrast, intact bacteria exhibited fivefold lower specific activity in the LAL assay but showed similar MD-2-dependent potency as purified endotoxin in inducing acute airway inflammation in mice. Pre-treatment of intact bacteria and organic dusts with 0.1 M Tris-HCl/10 mM EDTA increased by fivefold the release of endotoxin. These findings demonstrate that house dust and other organic dusts should be extracted with Tris/EDTA to more accurately assess the endotoxin content and pro-inflammatory potential of these environmental samples.
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Affiliation(s)
- Kimberly A. Hoppe Parr
- Department of Occupational & Environmental Health, The University of Iowa, Iowa City, IA 52242, USA
| | - Suzana Hađina
- Department of Occupational & Environmental Health, The University of Iowa, Iowa City, IA 52242, USA
| | - Brita Kilburg-Basnyat
- Department of Occupational & Environmental Health, The University of Iowa, Iowa City, IA 52242, USA
| | - Yifang Wang
- Department of Occupational & Environmental Health, The University of Iowa, Iowa City, IA 52242, USA
| | - Dulce Chavez
- Department of Occupational & Environmental Health, The University of Iowa, Iowa City, IA 52242, USA
| | - Peter S. Thorne
- Department of Occupational & Environmental Health, The University of Iowa, Iowa City, IA 52242, USA
| | - Jerrold P. Weiss
- Departments of Internal Medicine and Microbiology and Inflammation Program, The University of Iowa, Iowa City, IA 52242, USA
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23
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Borzęcka-Solarz K, Dembińska J, Hromada-Judycka A, Traczyk G, Ciesielska A, Ziemlińska E, Świątkowska A, Kwiatkowska K. Association of Lyn kinase with membrane rafts determines its negative influence on LPS-induced signaling. Mol Biol Cell 2017; 28:1147-1159. [PMID: 28228554 PMCID: PMC5391190 DOI: 10.1091/mbc.e16-09-0632] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 01/24/2017] [Accepted: 02/17/2017] [Indexed: 12/26/2022] Open
Abstract
Bacterial lipopolysaccharide activates Toll-like receptor 4 (TLR4) and triggers proinflammatory reactions of macrophages. TLR4 signaling is negatively regulated by Lyn tyrosine kinase, provided the kinase accumulates in membrane rafts as a result of palmitoylation, the catalytic activity, and SH2- and SH3-mediated intermolecular interactions. Lipopolysaccharide (LPS) is the component of Gram-negative bacteria that activates Toll-like receptor 4 (TLR4) to trigger proinflammatory responses. We examined the involvement of Lyn tyrosine kinase in TLR4 signaling of macrophages, distinguishing its catalytic activity and intermolecular interactions. For this, a series of Lyn-GFP constructs bearing point mutations in particular domains of Lyn were overexpressed in RAW264 macrophage-like cells or murine peritoneal macrophages, and their influence on LPS-induced responses was analyzed. Overproduction of wild-type or constitutively active Lyn inhibited production of TNF-α and CCL5/RANTES cytokines and down-regulated the activity of NFκB and IRF3 transcription factors in RAW264 cells. The negative influence of Lyn was nullified by point mutations of Lyn catalytic domain or Src homology 2 (SH2) or SH3 domains or of the cysteine residue that undergoes LPS-induced palmitoylation. Depending on the cell type, overproduction of those mutant forms of Lyn could even up-regulate LPS-induced responses, and this effect was reproduced by silencing of endogenous Lyn expression. Simultaneously, the Lyn mutations blocked its LPS-induced accumulation in the raft fraction of RAW264 cells. These data indicate that palmitoylation, SH2- and SH3-mediated intermolecular interactions, and the catalytic activity of Lyn are required for its accumulation in rafts, thereby determining the negative regulation of TLR4 signaling.
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Affiliation(s)
- Kinga Borzęcka-Solarz
- Laboratory of Molecular Membrane Biology, Department of Cell Biology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw 02-093, Poland
| | - Justyna Dembińska
- Laboratory of Molecular Membrane Biology, Department of Cell Biology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw 02-093, Poland
| | - Aneta Hromada-Judycka
- Laboratory of Molecular Membrane Biology, Department of Cell Biology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw 02-093, Poland
| | - Gabriela Traczyk
- Laboratory of Molecular Membrane Biology, Department of Cell Biology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw 02-093, Poland
| | - Anna Ciesielska
- Laboratory of Molecular Membrane Biology, Department of Cell Biology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw 02-093, Poland
| | - Ewelina Ziemlińska
- Laboratory of Molecular Membrane Biology, Department of Cell Biology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw 02-093, Poland
| | - Anna Świątkowska
- Laboratory of Molecular Membrane Biology, Department of Cell Biology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw 02-093, Poland
| | - Katarzyna Kwiatkowska
- Laboratory of Molecular Membrane Biology, Department of Cell Biology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw 02-093, Poland
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Wacker MA, Teghanemt A, Weiss JP, Barker JH. High-affinity caspase-4 binding to LPS presented as high molecular mass aggregates or in outer membrane vesicles. Innate Immun 2017; 23:336-344. [PMID: 28409545 DOI: 10.1177/1753425917695446] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Caspases of the non-canonical inflammasome (caspases -4, -5, and -11) directly bind endotoxin (LOS/LPS) and can be activated in the absence of any co-factors. Models of LPS-induced caspase activation have postulated that 1:1 binding of endotoxin monomers to caspase trigger caspase oligomerization and activation, analogous to that established for endotoxin-induced activation of MD-2/TLR4. However, using metabolically radiolabeled LOS and LPS, we now show high affinity and selective binding of caspase-4 to high molecular mass aggregates of purified endotoxin and to endotoxin-rich outer membrane vesicles without formation of 1:1 endotoxin:caspase complexes. Thus, our findings demonstrate markedly different endotoxin recognition properties of caspase-4 from that of MD-2/TLR4 and strongly suggest that activation of caspase-4 (and presumably caspase-5 and caspase-11) are mediated by interactions with activating endotoxin-rich membrane interfaces rather than by endotoxin monomers.
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Affiliation(s)
- Mark A Wacker
- 1 Department of Biology, Central Michigan University, Mt. Pleasant, MI, USA
| | - Athmane Teghanemt
- 2 Inflammation Program, University of Iowa, and Iowa City VA Health Care System, Iowa City, IA, USA.,3 Department of Internal Medicine, University of Iowa, and Iowa City VA Health Care System, Iowa City, IA, USA
| | - Jerrold P Weiss
- 2 Inflammation Program, University of Iowa, and Iowa City VA Health Care System, Iowa City, IA, USA.,3 Department of Internal Medicine, University of Iowa, and Iowa City VA Health Care System, Iowa City, IA, USA.,4 Department of Microbiology, University of Iowa, and Iowa City VA Health Care System, Iowa City, IA, USA
| | - Jason H Barker
- 2 Inflammation Program, University of Iowa, and Iowa City VA Health Care System, Iowa City, IA, USA.,3 Department of Internal Medicine, University of Iowa, and Iowa City VA Health Care System, Iowa City, IA, USA.,4 Department of Microbiology, University of Iowa, and Iowa City VA Health Care System, Iowa City, IA, USA
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25
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Ciesielska A, Sas-Nowosielska H, Kwiatkowska K. Bis(monoacylglycero)phosphate inhibits TLR4-dependent RANTES production in macrophages. Int J Biochem Cell Biol 2016; 83:15-26. [PMID: 27939812 DOI: 10.1016/j.biocel.2016.12.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 11/14/2016] [Accepted: 12/06/2016] [Indexed: 01/10/2023]
Abstract
Toll-like receptor 4 (TLR4) is the receptor for bacterial lipopolysaccharide (LPS) triggering production of pro-inflammatory cytokines which help eradicate the bacteria but could also be harmful when overproduced. The signaling activity of TLR4 is modulated by cholesterol level in cellular membranes, which in turn is affected by bis(monoacylglycero)phosphate (BMP), a phospholipid enriched in late endosomes. We found that exogenously added BMP isomers become incorporated into the plasma membrane and intracellular vesicles of macrophages and strongly reduced LPS-stimulated production of a chemokine RANTES, which was correlated with inhibition of interferon regulatory factor 3 (IRF3) controlling Rantes expression. To investigate the mechanism underlying the influence of BMP on TLR4 signaling we applied Laurdan and studied the impact of BMP incorporation on lipid packing, a measure for membrane order. Enrichment of model and cellular membranes with BMP significantly reduced their order and the reduction was maintained during stimulation of cells with LPS. This effect of BMP was abolished by enrichment of macrophages with cholesterol. In parallel, the inhibitory effect of BMP exerted on the TLR4-dependent phosphorylation of IRF3 was also reversed. Taken together our results indicate that BMP reduces the order of macrophage membranes which contributes to the inhibition of TLR4-dependent RANTES production.
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Affiliation(s)
- Anna Ciesielska
- Laboratory of Molecular Membrane Biology, Department of Cell Biology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland
| | - Hanna Sas-Nowosielska
- Laboratory for Imaging Tissue Structure and Function, Neurobiology Center, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland
| | - Katarzyna Kwiatkowska
- Laboratory of Molecular Membrane Biology, Department of Cell Biology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland.
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26
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Płóciennikowska A, Hromada-Judycka A, Dembinńska J, Roszczenko P, Ciesielska A, Kwiatkowska K. Contribution of CD14 and TLR4 to changes of the PI(4,5)P2
level in LPS-stimulated cells. J Leukoc Biol 2016; 100:1363-1373. [DOI: 10.1189/jlb.2vma1215-577r] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 06/12/2016] [Accepted: 06/29/2016] [Indexed: 01/09/2023] Open
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27
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Lu M, Munford R. LPS stimulates IgM production in vivo without help from non-B cells. Innate Immun 2016; 22:307-15. [DOI: 10.1177/1753425916644675] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 03/23/2016] [Indexed: 01/20/2023] Open
Abstract
Gram-negative bacterial LPS induce murine B-cell activation and innate (polyclonal) Ab production. Mouse B cells express the LPS signaling receptor (TLR4), yet how LPS activates B-cell responses in vivo is not known. Can LPS directly stimulate B cells to induce innate Ab production? Is activation of non-B cells also required? To address these questions, we transfused LPS-responsive ( Tlr4+/+) or non-responsive ( Tlr4−/−) B cells into LPS-responsive or non-responsive mice. Increased expression of the early activation markers CD69 and CD86 could be induced on transfused Tlr4−/− B cells by injecting LPS subcutaneously into Tlr4+/+ mice, demonstrating indirect activation of B cells by TLR4-responsive non-B cells in vivo, but the Tlr4−/− B cells did not increase serum IgM levels. In contrast, when Tlr4−/− recipients were transfused with Tlr4+/+ B cells, LPS induced large amounts of serum IgM and LPS could also enhance specific Ab production to a protein that was co-injected with it (adjuvant response). Thus, LPS-exposed non-B cells mediated increased surface expression of early B-cell activation markers, but this response did not predict innate Ab responses or LPS adjuvanticity in vivo. Direct stimulation of B cells by LPS via TLR4 was necessary and sufficient to induce B cells to produce Ab in vivo.
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Affiliation(s)
- Mingfang Lu
- Department of Immunology, School of Basic Medical Sciences, and Research Center on Aging and Medicine, Fudan University, Shanghai, China
- Laboratory of Clinical Infectious Diseases, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Robert Munford
- Laboratory of Clinical Infectious Diseases, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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28
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Martin T, Diaz I, Kilbourne J, Almarza O, Segovia C, Curtiss R, Santander J. Influence of lipopolysaccharide outer-core in the intrinsic resistance to antimicrobial peptides and virulence in Edwardsiella ictaluri. Microb Pathog 2016; 93:204-12. [PMID: 26945561 DOI: 10.1016/j.micpath.2016.02.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 01/10/2016] [Accepted: 02/29/2016] [Indexed: 02/06/2023]
Abstract
The genus Edwardsiella consists of bacteria with an intrinsic resistance to cyclic cationic antimicrobial peptides (CAMPs). Edwardsiella ictaluri, a pathogen of the catfish (Ictalurus punctatus) and the causative agent of a systemic infection, is highly resistant to CAMPs. Previously, we determined that the oligo-polysaccharide (O-PS) of the lipopolysaccharide (LPS) does not play a role in the E. ictaluri CAMP resistance and an intact core-lipid A structure is necessary for CAMPs resistance. Here, we evaluated the influence of the outer-core in the CAMPs resistance and fish virulence. E. ictaluri wabG, a gene that encodes for the UDP-glucuronic acid transferase that links the lipid A-inner-core to the outer-core-oligopolysaccharides, was deleted. Deletion of ΔwabG caused a pleiotropic effect, influencing LPS synthesis, CAMPs resistance, growth, and biofilm formation. E. ictaluri ΔwabG was attenuated in zebrafish indicating the important role of LPS during fish pathogenesis. Also, we evaluated the inflammatory effects of wabG LPS in catfish ligated loop model, showing a decreased inflammatory effect at the gut level respects to the E. ictaluri wild type. We conclude that E. ictaluri CAMPs resistance is related to the molecules present in the LPS outer-core and that fish gut inflammation triggered by E. ictaluri is LPS dependent, reinforcing the hypothesis that fish gut recognizes LPS in an O-PS dependent fashion.
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Affiliation(s)
- Taylor Martin
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA; School of Life and Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Ignacia Diaz
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA; Microbial Pathogenesis and Vaccinology Research Group, Faculty of Sciences, Universidad Mayor, Huechuraba 8580745, Chile
| | - Jacquelyn Kilbourne
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA
| | - Oscar Almarza
- Microbial Pathogenesis and Vaccinology Research Group, Faculty of Sciences, Universidad Mayor, Huechuraba 8580745, Chile
| | - Cristopher Segovia
- Microbial Pathogenesis and Vaccinology Research Group, Faculty of Sciences, Universidad Mayor, Huechuraba 8580745, Chile; PhD Program in Integrative Genomics, Faculty of Sciences, Universidad Mayor, Huechuraba 8580745, Chile
| | - Roy Curtiss
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA; School of Life and Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Javier Santander
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA; School of Life and Sciences, Arizona State University, Tempe, AZ 85287, USA; Microbial Pathogenesis and Vaccinology Research Group, Faculty of Sciences, Universidad Mayor, Huechuraba 8580745, Chile.
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29
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Vašl J, Oblak A, Peternelj TT, Klett J, Martín-Santamaría S, Gioannini TL, Weiss JP, Jerala R. Molecular Basis of the Functional Differences between Soluble Human Versus Murine MD-2: Role of Val135 in Transfer of Lipopolysaccharide from CD14 to MD-2. THE JOURNAL OF IMMUNOLOGY 2016; 196:2309-18. [PMID: 26826249 DOI: 10.4049/jimmunol.1502074] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 12/26/2015] [Indexed: 11/19/2022]
Abstract
Myeloid differentiation factor 2 (MD-2) is an extracellular protein, associated with the ectodomain of TLR4, that plays a critical role in the recognition of bacterial LPS. Despite high overall structural and functional similarity, human (h) and murine (m) MD-2 exhibit several species-related differences. hMD-2 is capable of binding LPS in the absence of TLR4, whereas mMD-2 supports LPS responsiveness only when mMD-2 and mTLR4 are coexpressed in the same cell. Previously, charged residues at the edge of the LPS binding pocket have been attributed to this difference. In this study, site-directed mutagenesis was used to explore the hydrophobic residues within the MD-2 binding pocket as the source of functional differences between hMD-2 and mMD-2. Whereas decreased hydrophobicity of residues 61 and 63 in the hMD-2 binding pocket retained the characteristics of wild-type hMD-2, a relatively minor change of valine to alanine at position 135 completely abolished the binding of LPS to the hMD-2 mutant. The mutant, however, retained the LPS binding in complex with TLR4 and also cell activation, resulting in a murine-like phenotype. These results were supported by the molecular dynamics simulation. We propose that the residue at position 135 of MD-2 governs the dynamics of the binding pocket and its ability to accommodate lipid A, which is allosterically affected by bound TLR4.
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Affiliation(s)
- Jožica Vašl
- Department of Biotechnology, National Institute of Chemistry, 1000 Ljubljana, Slovenia
| | - Alja Oblak
- Department of Biotechnology, National Institute of Chemistry, 1000 Ljubljana, Slovenia
| | - Tina T Peternelj
- Department of Biotechnology, National Institute of Chemistry, 1000 Ljubljana, Slovenia
| | - Javier Klett
- Center for Biological Research, Superior Council for Scientific Research, 28040 Madrid, Spain
| | | | - Theresa L Gioannini
- Inflammation Program, Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, IA 52241; Veterans Affairs Medical Center, Iowa City, IA 52246; and
| | - Jerrold P Weiss
- Inflammation Program, Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, IA 52241
| | - Roman Jerala
- Department of Biotechnology, National Institute of Chemistry, 1000 Ljubljana, Slovenia; Excellent Nuclear Magnetic Resonance-Future Innovation for Sustainable Technologies Center of Excellence, 1000 Ljubljana, Slovenia
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30
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Płóciennikowska A, Zdioruk MI, Traczyk G, Świątkowska A, Kwiatkowska K. LPS-induced clustering of CD14 triggers generation of PI(4,5)P2. J Cell Sci 2015; 128:4096-111. [PMID: 26446256 DOI: 10.1242/jcs.173104] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 09/30/2015] [Indexed: 01/08/2023] Open
Abstract
Bacterial lipopolysaccharide (LPS) induces strong pro-inflammatory reactions after sequential binding to CD14 protein and TLR4 receptor. Here, we show that CD14 controls generation of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] in response to LPS binding. In J774 cells and HEK293 cells expressing CD14 exposed to 10-100 ng/ml LPS, the level of PI(4,5)P2 rose in a biphasic manner with peaks at 5-10 min and 60 min. After 5-10 min of LPS stimulation, CD14 underwent prominent clustering in the plasma membrane, accompanied by accumulation of PI(4,5)P2 and type-I phosphatidylinositol 4-phosphate 5-kinase (PIP5K) isoforms Iα and Iγ (encoded by Pip5k1a and Pip5k1c, respectively) in the CD14 region. Clustering of CD14 with antibodies, without LPS and TLR4 participation, was sufficient to trigger PI(4,5)P2 elevation. The newly generated PI(4,5)P2 accumulated in rafts, which also accommodated CD14 and a large portion of PIP5K Iα and PIP5K Iγ. Silencing of PIP5K Iα and PIP5K Iγ, or application of drugs interfering with PI(4,5)P2 synthesis and availability, abolished the LPS-induced PI(4,5)P2 elevation and inhibited downstream pro-inflammatory reactions. Taken together, these data indicate that LPS induces clustering of CD14, which triggers PI(4,5)P2 generation in rafts that is required for maximal pro-inflammatory signaling of TLR4.
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Affiliation(s)
- Agnieszka Płóciennikowska
- Nencki Institute of Experimental Biology, Laboratory of Molecular Membrane Biology, 3 Pasteur St., Warsaw 02-093, Poland
| | - Mykola I Zdioruk
- Nencki Institute of Experimental Biology, Laboratory of Molecular Membrane Biology, 3 Pasteur St., Warsaw 02-093, Poland
| | - Gabriela Traczyk
- Nencki Institute of Experimental Biology, Laboratory of Molecular Membrane Biology, 3 Pasteur St., Warsaw 02-093, Poland
| | - Anna Świątkowska
- Nencki Institute of Experimental Biology, Laboratory of Molecular Membrane Biology, 3 Pasteur St., Warsaw 02-093, Poland
| | - Katarzyna Kwiatkowska
- Nencki Institute of Experimental Biology, Laboratory of Molecular Membrane Biology, 3 Pasteur St., Warsaw 02-093, Poland
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31
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Gioannini TL, Teghanemt A, Zhang D, Esparza G, Yu L, Weiss J. Purified monomeric ligand.MD-2 complexes reveal molecular and structural requirements for activation and antagonism of TLR4 by Gram-negative bacterial endotoxins. Immunol Res 2015; 59:3-11. [PMID: 24895101 DOI: 10.1007/s12026-014-8543-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A major focus of work in our laboratory concerns the molecular mechanisms and structural bases of Gram-negative bacterial endotoxin recognition by host (e.g., human) endotoxin-recognition proteins that mediate and/or regulate activation of Toll-like receptor (TLR) 4. Here, we review studies of wild-type and variant monomeric endotoxin.MD-2 complexes first produced and characterized in our laboratories. These purified complexes have provided unique experimental reagents, revealing both quantitative and qualitative determinants of TLR4 activation and antagonism. This review is dedicated to the memory of Dr. Theresa L. Gioannini (1949-2014) who played a central role in many of the studies and discoveries that are reviewed.
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Affiliation(s)
- Theresa L Gioannini
- The Inflammation Program, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 2501 Crosspark Rd, Coralville, IA, 52241, USA
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32
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Molecular simplification of lipid A structure: TLR4-modulating cationic and anionic amphiphiles. Mol Immunol 2015; 63:153-61. [DOI: 10.1016/j.molimm.2014.05.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 05/26/2014] [Accepted: 05/26/2014] [Indexed: 12/13/2022]
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Płóciennikowska A, Hromada-Judycka A, Borzęcka K, Kwiatkowska K. Co-operation of TLR4 and raft proteins in LPS-induced pro-inflammatory signaling. Cell Mol Life Sci 2014; 72:557-581. [PMID: 25332099 PMCID: PMC4293489 DOI: 10.1007/s00018-014-1762-5] [Citation(s) in RCA: 510] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 10/01/2014] [Accepted: 10/13/2014] [Indexed: 11/28/2022]
Abstract
Toll-like receptor 4 (TLR4) is activated by lipopolysaccharide (LPS), a component of Gram-negative bacteria to induce production of pro-inflammatory mediators aiming at eradication of the bacteria. Dysregulation of the host responses to LPS can lead to a systemic inflammatory condition named sepsis. In a typical scenario, activation of TLR4 is preceded by binding of LPS to CD14 protein anchored in cholesterol- and sphingolipid-rich microdomains of the plasma membrane called rafts. CD14 then transfers the LPS to the TLR4/MD-2 complex which dimerizes and triggers MyD88- and TRIF-dependent production of pro-inflammatory cytokines and type I interferons. The TRIF-dependent signaling is linked with endocytosis of the activated TLR4, which is controlled by CD14. In addition to CD14, other raft proteins like Lyn tyrosine kinase of the Src family, acid sphingomyelinase, CD44, Hsp70, and CD36 participate in the TLR4 signaling triggered by LPS and non-microbial endogenous ligands. In this review, we summarize the current state of the knowledge on the involvement of rafts in TLR4 signaling, with an emphasis on how the raft proteins regulate the TLR4 signaling pathways. CD14-bearing rafts, and possibly CD36-rich rafts, are believed to be preferred sites of the assembly of a multimolecular complex which mediates the endocytosis of activated TLR4.
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Affiliation(s)
- Agnieszka Płóciennikowska
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093, Warsaw, Poland
| | - Aneta Hromada-Judycka
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093, Warsaw, Poland
| | - Kinga Borzęcka
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093, Warsaw, Poland
| | - Katarzyna Kwiatkowska
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093, Warsaw, Poland.
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34
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Tan Y, Kagan JC. A cross-disciplinary perspective on the innate immune responses to bacterial lipopolysaccharide. Mol Cell 2014; 54:212-23. [PMID: 24766885 DOI: 10.1016/j.molcel.2014.03.012] [Citation(s) in RCA: 144] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The study of innate immunity to bacteria has focused heavily on the mechanisms by which mammalian cells detect lipopolysaccharide (LPS), the conserved surface component of Gram-negative bacteria. While Toll-like receptor 4 (TLR4) is responsible for all the host transcriptional responses to LPS, recent discoveries have revealed the existence of several TLR4-independent responses to LPS. These discoveries not only broaden our view of the means by which mammalian cells interact with bacteria, but they also highlight new selective pressures that may have promoted the evolution of bacterial immune evasion strategies. In this review, we highlight past and recent discoveries on host LPS sensing mechanisms and discuss bacterial countermeasures that promote infection. By looking at both sides of the host-pathogen interaction equation, we hope to provide comprehensive insights into host defense mechanisms and bacterial pathogenesis.
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Affiliation(s)
- Yunhao Tan
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Jonathan C Kagan
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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35
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Inflammatory effects of Edwardsiella ictaluri lipopolysaccharide modifications in catfish gut. Infect Immun 2014; 82:3394-404. [PMID: 24866806 DOI: 10.1128/iai.01697-14] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Bacterial lipopolysaccharides (LPS) are structural components of the outer membranes of Gram-negative bacteria and also are potent inducers of inflammation in mammals. Higher vertebrates are extremely sensitive to LPS, but lower vertebrates, like fish, are resistant to their systemic toxic effects. However, the effects of LPS on the fish intestinal mucosa remain unknown. Edwardsiella ictaluri is a primitive member of the Enterobacteriaceae family that causes enteric septicemia in channel catfish (Ictalurus punctatus). E. ictaluri infects and colonizes deep lymphoid tissues upon oral or immersion infection. Both gut and olfactory organs are the primary sites of invasion. At the systemic level, E. ictaluri pathogenesis is relatively well characterized, but our knowledge about E. ictaluri intestinal interaction is limited. Recently, we observed that E. ictaluri oligo-polysaccharide (O-PS) LPS mutants have differential effects on the intestinal epithelia of orally inoculated catfish. Here we evaluate the effects of E. ictaluri O-PS LPS mutants by using a novel catfish intestinal loop model and compare it to the rabbit ileal loop model inoculated with Salmonella enterica serovar Typhimurium LPS. We found evident differences in rabbit ileal loop and catfish ileal loop responses to E. ictaluri and S. Typhimurium LPS. We determined that catfish respond to E. ictaluri LPS but not to S. Typhimurium LPS. We also determined that E. ictaluri inhibits cytokine production and induces disruption of the intestinal fish epithelia in an O-PS-dependent fashion. The E. ictaluri wild type and ΔwibT LPS mutant caused intestinal tissue damage and inhibited proinflammatory cytokine synthesis, in contrast to E. ictaluri Δgne and Δugd LPS mutants. We concluded that the E. ictaluri O-PS subunits play a major role during pathogenesis, since they influence the recognition of the LPS by the intestinal mucosal immune system of the catfish. The LPS structure of E. ictaluri mutants is needed to understand the mechanism of interaction.
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Chen YF, Shiau AL, Wang SH, Yang JS, Chang SJ, Wu CL, Wu TS. Zhankuic acid A isolated from Taiwanofungus camphoratus is a novel selective TLR4/MD-2 antagonist with anti-inflammatory properties. THE JOURNAL OF IMMUNOLOGY 2014; 192:2778-86. [PMID: 24532584 DOI: 10.4049/jimmunol.1301931] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
TLR4, a membrane receptor that functions in complex with its accessory protein myeloid differentiation factor-2 (MD-2), is a therapeutic target for bacterial infections. Taiwanofungus camphoratus is highly valued as a medicinal mushroom for cancer, hypertension, and inflammation in traditional medicine. Zhankuic acid A (ZAA) is the major pharmacologically active compound of T. camphoratus. The mechanism of action of T. camphoratus or ZAA has not been fully elucidated. We analyzed the structure of human TLR4/MD-2 complex with ZAA by X-score and HotLig modeling approaches. Two Abs against MD-2 were used to verify the MD-2/ZAA interaction. The inflammation and survival of the mice pretreated with ZAA and injected with LPS were monitored. The modeling structure shows that ZAA binds the MD-2 hydrophobic pocket exclusively via specific molecular recognition; the contact interface is dominated by hydrophobic interactions. Binding of ZAA to MD-2 reduced Ab recognition to native MD-2, similar to the effect of LPS binding. Furthermore, ZAA significantly ameliorated LPS-induced endotoxemia and Salmonella-induced diarrhea in mice. Our results suggest that ZAA, which can compete with LPS for binding to MD-2 as a TLR4/MD-2 antagonist, may be a potential therapeutic agent for gram-negative bacterial infections.
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Affiliation(s)
- Yu-Fon Chen
- Institute of Life Sciences, National Cheng Kung University, Tainan 70101, Taiwan
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37
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Teghanemt A, Weiss JP, Gioannini TL. Radioiodination of an endotoxin·MD-2 complex generates a novel sensitive, high-affinity ligand for TLR4. Innate Immun 2013; 19:545-60. [PMID: 23439691 DOI: 10.1177/1753425913475688] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A purified complex of metabolically labeled [(3)H]lipooligosaccharide (LOS) and recombinant human myeloid differentiation factor 2 (MD-2), [(3)H]LOS·MD-2, has been used to demonstrate pM affinity binding interactions with soluble TLR4 ectodomain (TLR4ecd). For measurement of the binding parameters of membrane-bound TLR4, we took advantage of the stability of endotoxin·MD-2 and tyrosine(s) present on the surface of MD-2 to radioiodinate LOS·MD-2. Radioiodinated LOS·MD-2 generated a reagent with an estimated 1:1 molar ratio of [(125)I] to sMD-2 with 20-fold higher specific radioactivity and TLR4-activating properties comparable to metabolically-labeled LOS·MD-2. LOS·MD-2[(125)I] and [(3)H]LOS·MD-2 have similar affinities for soluble (FLAG) TLR4ecd and for membrane-bound TLR4 in HEK293T/TLR4 cells. In a similar dose-dependent manner, sMD-2 and LOS·MD-2 inhibit LOS·MD-2[(125)I] binding to TLR4 indicating the pM affinity binding of LOS·MD-2[(125)I] is agonist-independent. LOS·MD-2[(125)I] allowed measurement of low levels of cell-surface human or murine TLR4 expressed by stable cell lines (2000-3000 sites/cell) and quantitatively measures low levels of 'MD-2-free' TLR4 (est. 250 molecules/cell) in cells co-expressing TLR4 and MD-2. Occupation of 50-100 TLR4/cell by LOS·MD-2 is sufficient to trigger measurable TLR4-dependent cell activation. LOS·MD-2[(125)I] provides a powerful reagent to measure quantitatively functional human and murine cell-surface TLR4, including in cells where surface TLR4 is potentially functionally significant but not detectable by other methods.
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Affiliation(s)
- Athmane Teghanemt
- 1Inflammation Program, Department of Internal Medicine, Roy A. and Lucille J. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
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Ranoa DRE, Kelley SL, Tapping RI. Human lipopolysaccharide-binding protein (LBP) and CD14 independently deliver triacylated lipoproteins to Toll-like receptor 1 (TLR1) and TLR2 and enhance formation of the ternary signaling complex. J Biol Chem 2013; 288:9729-9741. [PMID: 23430250 DOI: 10.1074/jbc.m113.453266] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bacterial lipoproteins are the most potent microbial agonists for the Toll-like receptor 2 (TLR2) subfamily, and this pattern recognition event induces cellular activation, leading to host immune responses. Triacylated bacterial lipoproteins coordinately bind TLR1 and TLR2, resulting in a stable ternary complex that drives intracellular signaling. The sensitivity of TLR-expressing cells to lipoproteins is greatly enhanced by two lipid-binding serum proteins known as lipopolysaccharide-binding protein (LBP) and soluble CD14 (sCD14); however, the physical mechanism that underlies this increased sensitivity is not known. To address this, we measured the ability of LBP and sCD14 to drive ternary complex formation between soluble extracellular domains of TLR1 and TLR2 and a synthetic triacylated lipopeptide agonist. Importantly, addition of substoichiometric amounts of either LBP or sCD14 significantly enhanced formation of a TLR1·TLR2 lipopeptide ternary complex as measured by size exclusion chromatography. However, neither LBP nor sCD14 was physically associated with the final ternary complex. Similar results were obtained using outer surface protein A (OspA), a naturally occurring triacylated lipoprotein agonist from Borrelia burgdorferi. Activation studies revealed that either LBP or sCD14 sensitized TLR-expressing cells to nanogram levels of either the synthetic lipopeptide or OspA lipoprotein agonist. Together, our results show that either LBP or sCD14 can drive ternary complex formation and TLR activation by acting as mobile carriers of triacylated lipopeptides or lipoproteins.
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Affiliation(s)
- Diana Rose E Ranoa
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Stacy L Kelley
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Richard I Tapping
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801; Department of College of Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801.
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Cellular distribution of lipid A and LPS R595 after in vitro application to isolated human monocytes by freeze-fracture replica immunogold-labelling. Innate Immun 2013; 19:588-95. [DOI: 10.1177/1753425912473851] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We have performed freeze-fracture replica immunogold labelling of endotoxin preparations (lipid A and deep rough mutant LPS Re from Salmonella enterica sv. Minnesota), i.e. adding the endotoxins to human monocytes, labelling with monoclonal Abs recognizing either lipid A or LPS Re (A6 and A20 respectively), and fixing with immunogold secondary Ab. We have found that the endotoxins intercalated into the cell membranes with subsequent internalization by the cells. Surprisingly, membrane uptake took place only in the inner, plasmic leaflet of the plasma membrane, but there was no uptake of the outer leaflet for both compounds. Remarkable labelling could be also found for the two membranes of the nuclear envelope—in the case of lipid A only at the plasmic leaflet, but in the case of LPS Re on both leaflets. Isothermal calorimetric titration of the AB A20 with LPS and phospholipids showed that the Ab may bind not only to LPS but also to negatively charged phosphatidylserine. These results are discussed in the frame of the published concepts of cell activation induced by the endotoxins, i.e. how they are able to cause a conformational change of signalling proteins, such as the TLR4/MD2 complex.
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40
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Abstract
There are at least five families of microbe-detection receptors that function to detect and eradicate potentially infectious microorganisms that enter multicellular eukaryotes. While a multitude of proteins regulating innate immune signal transduction have already been defined, continuous genetic screening for regulators of innate immunity may not yield as significant insight into the operation of these pathways as was obtained in the past. This diminished return on experimental investment suggests that we are approaching the asymptote of genetics-only approaches to study innate immunity. In contrast, it remains unclear how known regulators of innate immunity interact within the infrastructure of mammalian cells to execute their signaling functions. In this Perspective, I first highlight the locations within mammalian cells that permit innate immune signal transduction and then offer a model whereby structurally distinct proteins can be grouped functionally through their ability to assemble platforms of regulators on the signaling organelles of the innate immune system.
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Affiliation(s)
- Jonathan C Kagan
- Harvard Medical School and Division of Gastroenterology, Children's Hospital Boston, Boston, MA 02115, USA.
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41
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Schlatzer DM, Dazard JE, Ewing RM, Ilchenko S, Tomcheko SE, Eid S, Ho V, Yanik G, Chance MR, Cooke KR. Human biomarker discovery and predictive models for disease progression for idiopathic pneumonia syndrome following allogeneic stem cell transplantation. Mol Cell Proteomics 2012; 11:M111.015479. [PMID: 22337588 PMCID: PMC3433920 DOI: 10.1074/mcp.m111.015479] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 02/10/2012] [Indexed: 11/06/2022] Open
Abstract
Allogeneic hematopoietic stem cell transplantation (SCT) is the only curative therapy for many malignant and nonmalignant conditions. Idiopathic pneumonia syndrome (IPS) is a frequently fatal complication that limits successful outcomes. Preclinical models suggest that IPS represents an immune mediated attack on the lung involving elements of both the adaptive and the innate immune system. However, the etiology of IPS in humans is less well understood. To explore the disease pathway and uncover potential biomarkers of disease, we performed two separate label-free, proteomics experiments defining the plasma protein profiles of allogeneic SCT patients with IPS. Samples obtained from SCT recipients without complications served as controls. The initial discovery study, intended to explore the disease pathway in humans, identified a set of 81 IPS-associated proteins. These data revealed similarities between the known IPS pathways in mice and the condition in humans, in particular in the acute phase response. In addition, pattern recognition pathways were judged to be significant as a function of development of IPS, and from this pathway we chose the lipopolysaccaharide-binding protein (LBP) protein as a candidate molecular diagnostic for IPS, and verified its increase as a function of disease using an ELISA assay. In a separately designed study, we identified protein-based classifiers that could predict, at day 0 of SCT, patients who: 1) progress to IPS and 2) respond to cytokine neutralization therapy. Using cross-validation strategies, we built highly predictive classifier models of both disease progression and therapeutic response. In sum, data generated in this report confirm previous clinical and experimental findings, provide new insights into the pathophysiology of IPS, identify potential molecular classifiers of the condition, and uncover a set of markers potentially of interest for patient stratification as a basis for individualized therapy.
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Affiliation(s)
| | | | - Rob M. Ewing
- From the ‡Center for Proteomics and Bioinformatics
- §Department of Genetics
| | | | | | - Saada Eid
- ¶Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106
| | - Vincent Ho
- ‖Department of Pediatrics, Blood and Marrow Transplantation Program, University of Michigan, Ann Arbor, MI
| | - Greg Yanik
- **Department of Medical Oncology, Blood and Marrow Transplantation Program, Dana-Farber Cancer Institute, Boston, MA
| | - Mark R. Chance
- From the ‡Center for Proteomics and Bioinformatics
- §Department of Genetics
| | - Kenneth R. Cooke
- ¶Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106
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42
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Yu L, Phillips RL, Zhang D, Teghanemt A, Weiss JP, Gioannini TL. NMR studies of hexaacylated endotoxin bound to wild-type and F126A mutant MD-2 and MD-2·TLR4 ectodomain complexes. J Biol Chem 2012; 287:16346-55. [PMID: 22433852 DOI: 10.1074/jbc.m112.343467] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Host response to invasion by many gram-negative bacteria depends upon activation of Toll-like receptor 4 (TLR4) by endotoxin presented as a monomer bound to myeloid differentiation factor 2 (MD-2). Metabolic labeling of hexaacylated endotoxin (LOS) from Neisseria meningitidis with [(13)C]acetate allowed the use of NMR to examine structural properties of the fatty acyl chains of LOS present in TLR4-agonistic and -antagonistic binary and ternary complexes with, respectively, wild-type or mutant (F126A) MD-2 ± TLR4 ectodomain. Chemical shift perturbation indicates that Phe(126) affects the environment and/or position of each of the bound fatty acyl chains both in the binary LOS·MD-2 complex and in the ternary LOS·MD-2·TLR4 ectodomain complex. In both wild-type and mutant LOS·MD-2 complexes, one of the six fatty acyl chains of LOS is more susceptible to paramagnetic attenuation, suggesting protrusion of that fatty acyl chain from the hydrophobic pocket of MD-2, independent of association with TLR4. These findings indicate that re-orientation of the aromatic side chain of Phe(126) is induced by binding of hexaacylated E, preceding interaction with TLR4. This re-arrangement of Phe(126) may act as a "hydrophobic switch," driving agonist-dependent contacts needed for TLR4 dimerization and activation.
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Affiliation(s)
- Liping Yu
- NMR Core Facility, Roy A. and Lucille J. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52241, USA
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43
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Esparza GA, Teghanemt A, Zhang D, Gioannini TL, Weiss JP. Endotoxin{middle dot}albumin complexes transfer endotoxin monomers to MD-2 resulting in activation of TLR4. Innate Immun 2011; 18:478-91. [PMID: 21994253 DOI: 10.1177/1753425911422723] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Response to Gram-negative bacteria (GNB) is partially mediated by the recognition of GNB-derived endotoxin by host cells. Potent host response to endotoxin depends on the sequential interaction of endotoxin with lipopolysaccharide binding protein (LBP), CD14, MD-2 and TLR4. While CD14 facilitates the efficient transfer of endotoxin monomers to MD-2 and MD-2·TLR4, activation of MD-2·TLR4 can occur in the absence of CD14 through an unknown mechanism. Here, we show that incubation of purified endotoxin (E) aggregates (E(agg), M ( r ) ≥ 20 million) in PBS with ≥ 0.1% albumin in the absence of divalent cations Ca(2+) and Mg(2+), yields E·albumin complexes (M ( r ) ∼70,000). E·albumin transfers E monomers to sMD-2 or sMD-2·TLR4 ectodomain (TLR4(ecd)) with a 'K (d)' of ∼4 nM and induces MD-2·TLR4-dependent, CD14-independent cell activation with a potency only 10-fold less than that of monomeric E·CD14 complexes. Our findings demonstrate, for the first time, a mechanistic basis for delivery of endotoxin monomers to MD-2 and for activation of TLR4 that is independent of CD14.
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Affiliation(s)
- Gregory A Esparza
- Immunology Program, University of Iowa Graduate College, Iowa City, Iowa, USA
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44
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DeMarco ML, Woods RJ. From agonist to antagonist: structure and dynamics of innate immune glycoprotein MD-2 upon recognition of variably acylated bacterial endotoxins. Mol Immunol 2011; 49:124-33. [PMID: 21924775 DOI: 10.1016/j.molimm.2011.08.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Revised: 08/01/2011] [Accepted: 08/06/2011] [Indexed: 11/17/2022]
Abstract
The human immune response to an infection by Gram-negative bacteria involves detection of lipopolysaccharides (LPS), also known as endotoxins, which comprise the bacterial outer cell wall. Distinct from mammalian glycolipid structures, LPS have a conserved chemical pattern that is recognized by the pattern recognition receptor complex formed by myeloid differentiation protein 2 (MD-2) and toll-like receptor 4 (TLR4). A remarkable immune-mediated structure-toxicity relationship has been defined that relates to the number of acyl chains in the endotoxin. While there is a clear correlation between endotoxin acylation and elicited agonist or antagonist responses, the 3D structural basis of this relationship remains unclear. In order to explore, at atomic-resolution, the effects of a range of chemically distinct endotoxins on the structure and dynamics of their MD-2·endotoxin complexes, we examined a series of variably acylated lipid A molecules from Escherichia coli and Neisseria meningitidis in complex with human MD-2. Through the application of molecular dynamics simulations, in concert with experimental data, we have identified specific structural and dynamic features of the MD-2-endotoxin complexes that may control dimerization of TLR4 molecules. As dimerization is central to the release of downstream chemical mediators, the results provide a structural foundation for the ability of endotoxins to act as either agonists or antagonists of the TLR4 pathway.
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Affiliation(s)
- Mari L DeMarco
- Complex Carbohydrate Research Center, University of Georgia, GA 30602, USA.
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45
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Richter W, Vogel V, Howe J, Steiniger F, Brauser A, Koch MH, Roessle M, Gutsmann T, Garidel P, Mäntele W, Brandenburg K. Morphology, size distribution, and aggregate structure of lipopolysaccharide and lipid A dispersions from enterobacterial origin. Innate Immun 2010; 17:427-38. [PMID: 20682588 DOI: 10.1177/1753425910372434] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Lipopolysaccharides (LPSs) from Gram-negative bacteria are strong elicitors of the human immune systems. There is strong evidence that aggregates and not monomers of LPS play a decisive role at least in the initial stages of cell activation of immune cells such as mononuclear cells. In previous reports, it was shown that the biologically most active part of enterobacterial LPS, hexa-acyl bisphosphorylated lipid A, adopts a particular supramolecular conformation, a cubic aggregate structure. However, little is known about the size and morphology of these aggregates, regarding the fact that LPS may have strong variations in the length of the saccharide chains (various rough mutant and smooth-form LPS). Thus, in the present paper, several techniques for the determination of details of the aggregate morphology such as freeze-fracture and cryo-electron microscopy, analytical ultracentrifugation, laser backscattering analysis, and small-angle X-ray scattering were applied for various endotoxin (lipid A and different LPS) preparations. The data show a variety of different morphologies not only for different endotoxins but also when comparing different applied techniques. The data are interpreted with respect to the suitability of the single techniques, in particular on the basis of available literature data.
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Affiliation(s)
- Walter Richter
- Elektronenmikroskopisches Zentrum, Friedrich-Schiller-Universität Jena, Germany
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Vasl J, Oblak A, Gioannini TL, Weiss JP, Jerala R. Novel roles of lysines 122, 125, and 58 in functional differences between human and murine MD-2. THE JOURNAL OF IMMUNOLOGY 2009; 183:5138-45. [PMID: 19783674 DOI: 10.4049/jimmunol.0901544] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The MD-2/TLR4 complex provides a highly robust mechanism for recognition and response of mammalian innate immunity to Gram-negative bacterial endotoxins. Despite overall close structural and functional similarity, human (h) and murine (m) MD-2 show several species-related differences, including the ability of hMD-2, but not mMD-2, to bind endotoxin (E) in the absence of TLR4. Wild-type mMD-2 can support TLR4-dependent cell activation by E only when mMD-2 and mTLR4 are coexpressed in the same cell. However, replacement of Glu122, Leu125, and/or Asn58 of mMD-2 with the corresponding residues (lysines) of hMD-2 was sufficient to yield soluble extracellular MD-2 that reacted with monomeric E . sCD14 complex to form extracellular monomeric E . MD-2 that activated cells expressing TLR4 without MD-2. Moreover, in contrast to wild-type mMD-2, double and triple mMD-2 mutants also supported E-triggered signaling in combination with human TLR4. Conversely, a K125L mutant of hMD-2 reacted with E . CD14 and activated TLR4 only when coexpressed with TLR4, and not when secreted without TLR4. These findings reveal novel roles of lysines 122, 125, and 58 in human MD-2 that contribute to the functional differences between human and murine MD-2 and, potentially, to differences in the sensitivity of humans and mice to endotoxin.
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Affiliation(s)
- Jozica Vasl
- Department of Biotechnology, National Institute of Chemistry, Ljubljana, Slovenia
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47
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NATHE KATHERYNE, PARAD RICHARD, VAN MARTER LINDAJ, LUND CARAA, SUTER EUGÉNIEE, HERNANDEZ-DIAZ SONIA, BOUSH ELIZABETHBG, IKONOMU EVA, MOREY JOANN, ZEMAN ALENKAM, MCNAMARA MEAGHAN, LEVY OFER, Levy O. Endotoxin-directed innate immunity in tracheal aspirates of mechanically ventilated human neonates. Pediatr Res 2009; 66:191-6. [PMID: 19390484 PMCID: PMC3992717 DOI: 10.1203/pdr.0b013e3181aa33d7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Mechanical ventilation of preterm infants is associated with pulmonary inflammation. Intubated infants often develop bacterial tracheal colonization, but little is known about endotoxin in tracheal aspirates (TAs) or the mobilization of innate immunity toward endotoxin, a potent stimulus that contributes to inflammatory disease. We characterized mobilization of endotoxin-directed innate immunity in TAs from an observational cohort of mechanically ventilated neonates. TA supernatants (n = 42; GA = 23-40 wk, postnatal age = 1-71 d) were assayed for endotoxin (Limulus amoebocyte lysate assay) and endotoxin-modulating proteins: bactericidal/ permeability-increasing protein (BPI), LPS-binding protein (LBP), and soluble cell differentiation antigen 14 (sCD14). TA cellular BPI was measured by ELISA, Western blot, flow cytometry, and bactericidal assay. TA mRNAs encoding endotoxin-modulating proteins were measured by quantitative real-time PCR (qRT-PCR). Endotoxin in TA supernatants was proportional to both postnatal age and polymorphonuclear leukocytes (PMN). Neonatal TAs were rich in PMN containing BPI and expressed mRNAs encoding Toll-like receptor (TLR) 4, CD14, and myeloid differentiation protein 2 (MD-2). Extracellular BPI was consistently detectable and correlated with TA PMN and GA. Both extracellular- and cellular-BPI increased during the first postnatal week. TA extracellular BPI, LBP, and sCD14 were positively correlated. TAs from intubated neonates demonstrate endotoxin accumulation and mobilization of endotoxin-directed innate immunity, potentially contributing to pulmonary inflammation.
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Affiliation(s)
- KATHERYN E. NATHE
- Division of Newborn Medicine, Children's Hospital Boston, Boston, MA 02115, USA, Department of Newborn Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA, Harvard Medical School, Boston, MA 02115, USA
| | - RICHARD PARAD
- Division of Newborn Medicine, Children's Hospital Boston, Boston, MA 02115, USA, Department of Newborn Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA, Harvard Medical School, Boston, MA 02115, USA
| | - LINDA J. VAN MARTER
- Division of Newborn Medicine, Children's Hospital Boston, Boston, MA 02115, USA, Department of Newborn Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA, Harvard Medical School, Boston, MA 02115, USA
| | - CARA A. LUND
- Division of Infectious Diseases, Children's Hospital Boston, Boston, MA 02115, USA
| | - EUGÉNIE E. SUTER
- Division of Infectious Diseases, Children's Hospital Boston, Boston, MA 02115, USA
| | - SONIA HERNANDEZ-DIAZ
- Division of Pharmacoepidemiology, Harvard School of Public Health, Boston, MA, 02115, USA., Harvard Medical School, Boston, MA 02115, USA
| | | | - EVA IKONOMU
- Division of Infectious Diseases, Children's Hospital Boston, Boston, MA 02115, USA
| | - JO ANN MOREY
- Department of Newborn Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - ALENKA M. ZEMAN
- Department of Newborn Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - MEAGHAN MCNAMARA
- Department of Newborn Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - OFER LEVY
- Division of Infectious Diseases, Children's Hospital Boston, Boston, MA 02115, USA, Harvard Medical School, Boston, MA 02115, USA,Correspondence and requests for reprints should be addressed to: Ofer Levy M.D., Ph.D. Harvard Medical School Department of Medicine, Division of Infectious Diseases Children's Hospital Boston 300 Longwood Avenue, Enders 854 Boston, MA 02115 Office phone: (617) 919-2904 FAX: (617) 730-0255
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48
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Piazza M, Rossini C, Della Fiorentina S, Pozzi C, Comelli F, Bettoni I, Fusi P, Costa B, Peri F. Glycolipids and benzylammonium lipids as novel antisepsis agents: synthesis and biological characterization. J Med Chem 2009; 52:1209-13. [PMID: 19161283 DOI: 10.1021/jm801333m] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
New glycolipids and a benzylammonium lipid were rationally designed by varying the chemical structure of a D-glucose-derived hit compound active as lipid A antagonist. We report the synthesis of these compounds, their in vitro activity as lipid A antagonists on HEK cells, and the capacity to inhibit LPS-induced septic shock in vivo. The lack of toxicity and the good in vivo activity suggest the use of some compounds of the panel as hits for antisepsis drug development.
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Affiliation(s)
- Matteo Piazza
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milano, Italy
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49
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Kobayashi H, Kobayashi O, Kawai S. Pathogenesis and clinical manifestations of chronic colonization by Pseudomonas aeruginosa and its biofilms in the airway tract. J Infect Chemother 2009; 15:125-42. [PMID: 19554398 DOI: 10.1007/s10156-008-0691-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Indexed: 10/20/2022]
Affiliation(s)
- Hiroyuki Kobayashi
- First Department of Internal Medicine, Kyorin University, School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan
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50
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Brandenburg K, Seydel U. Conformation and Supramolecular Structure of Lipid A. LIPID A IN CANCER THERAPY 2009; 667:25-38. [DOI: 10.1007/978-1-4419-1603-7_3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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