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Hatton AA, Guerra FE. Scratching the Surface Takes a Toll: Immune Recognition of Viral Proteins by Surface Toll-like Receptors. Viruses 2022; 15:52. [PMID: 36680092 PMCID: PMC9863796 DOI: 10.3390/v15010052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 12/22/2022] [Accepted: 12/22/2022] [Indexed: 12/29/2022] Open
Abstract
Early innate viral recognition by the host is critical for the rapid response and subsequent clearance of an infection. Innate immune cells patrol sites of infection to detect and respond to invading microorganisms including viruses. Surface Toll-like receptors (TLRs) are a group of pattern recognition receptors (PRRs) that can be activated by viruses even before the host cell becomes infected. However, the early activation of surface TLRs by viruses can lead to viral clearance by the host or promote pathogenesis. Thus, a plethora of research has attempted to identify specific viral ligands that bind to surface TLRs and mediate progression of viral infection. Herein, we will discuss the past two decades of research that have identified specific viral proteins recognized by cell surface-associated TLRs, how these viral proteins and host surface TLR interactions affect the host inflammatory response and outcome of infection, and address why controversy remains regarding host surface TLR recognition of viral proteins.
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Affiliation(s)
- Alexis A. Hatton
- Department of Microbiology & Cell Biology, Montana State University, Bozeman, MT 59718, USA
| | - Fermin E. Guerra
- Department of Laboratory Medicine & Pathology, University of Washington, Seattle, WA 98195, USA
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2
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Gao P, Adachi T, Okai S, Morita N, Kitamura D, Shinkura R. Integrin CD11b provides a new marker of pre-germinal center IgA + B cells in murine Peyer's patches. Int Immunol 2021; 34:249-262. [PMID: 34971392 PMCID: PMC9020567 DOI: 10.1093/intimm/dxab113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 12/30/2021] [Indexed: 11/15/2022] Open
Abstract
Activated B cells can enter germinal centers (GCs) for affinity maturation to produce high-affinity antibodies. However, which activated B cells will enter GCs remains unknown. Here, we found a small population of CD11b+IgA+ B cells located outside of GCs in murine Peyer’s patches (PPs). After injection of the CD11b+IgA+ PP B cells into a PP of a recipient mouse, they entered GCs forty hours later. They expressed GC surface markers and pre-GC B cell genes, suggesting that CD11b provides a novel surface marker of pre-GC IgA+ B cells in murine PPs. Furthermore, independently of dendritic cell activation, CD11b expression on B cells can be induced by bacterial antigens, such as pam3CSK4 and heat-killed Escherichia coli in vitro. In addition, mice orally administered with pam3CSK4 or heat-killed E. coli increased the number of PP GC B cells within two days, and enhanced the mucosal antigen-specific IgA response. Our results demonstrate that the induction of CD11b on B cells is a promising marker for selecting an effective mucosal vaccine adjuvant.
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Affiliation(s)
- Peng Gao
- Institute for Quantitative Biosciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
- Graduate School of Frontier Science, University of Tokyo, Kashiwa-shi, Chiba 277-8561, Japan
| | - Takahiro Adachi
- Department of Precision Health, Medical Research Institute, Tokyo Medical and Dental University, Chiyoda-ku, Tokyo 101-0062, Japan
| | - Shinsaku Okai
- Department of Applied Immunology, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Naoki Morita
- Institute for Quantitative Biosciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Daisuke Kitamura
- Division of Cancer Biology, Research Institute for Biomedical Sciences (RIBS), Tokyo University of Science, Noda, Chiba 278-0022, Japan
| | - Reiko Shinkura
- Institute for Quantitative Biosciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
- Graduate School of Frontier Science, University of Tokyo, Kashiwa-shi, Chiba 277-8561, Japan
- Collaborative Research Institute for Innovative Microbiology, University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
- Correspondence to: R. Shinkura; E-mail:
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Abstract
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The development of
lipopeptides (lipidated peptides) for vaccines
is discussed, including their role as antigens and/or adjuvants. Distinct
classes of lipopeptide architectures are covered including simple
linear and ligated constructs and lipid core peptides. The design,
synthesis, and immunological responses of the important class of glycerol-based
Toll-like receptor agonist lipopeptides such as Pam3CSK4, which contains three palmitoyl chains and a CSK4 hexapeptide sequence, and many derivatives of this model immunogenic
compound are also reviewed. Self-assembled lipopeptide structures
including spherical and worm-like micelles that have been shown to
act as vaccine agents are also described. The work discussed includes
examples of lipopeptides developed with model antigens, as well as
for immunotherapies to treat many infectious diseases including malaria,
influenza, hepatitis, COVID-19, and many others, as well as cancer
immunotherapies. Some of these have proceeded to clinical development.
The research discussed highlights the huge potential of, and diversity
of roles for, lipopeptides in contemporary and future vaccine development.
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Affiliation(s)
- Ian W Hamley
- Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, U.K
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4
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Wadhawan A, Reynolds MA, Makkar H, Scott AJ, Potocki E, Hoisington AJ, Brenner LA, Dagdag A, Lowry CA, Dwivedi Y, Postolache TT. Periodontal Pathogens and Neuropsychiatric Health. Curr Top Med Chem 2021; 20:1353-1397. [PMID: 31924157 DOI: 10.2174/1568026620666200110161105] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 12/04/2019] [Accepted: 12/04/2019] [Indexed: 02/08/2023]
Abstract
Increasing evidence incriminates low-grade inflammation in cardiovascular, metabolic diseases, and neuropsychiatric clinical conditions, all important causes of morbidity and mortality. One of the upstream and modifiable precipitants and perpetrators of inflammation is chronic periodontitis, a polymicrobial infection with Porphyromonas gingivalis (P. gingivalis) playing a central role in the disease pathogenesis. We review the association between P. gingivalis and cardiovascular, metabolic, and neuropsychiatric illness, and the molecular mechanisms potentially implicated in immune upregulation as well as downregulation induced by the pathogen. In addition to inflammation, translocation of the pathogens to the coronary and peripheral arteries, including brain vasculature, and gut and liver vasculature has important pathophysiological consequences. Distant effects via translocation rely on virulence factors of P. gingivalis such as gingipains, on its synergistic interactions with other pathogens, and on its capability to manipulate the immune system via several mechanisms, including its capacity to induce production of immune-downregulating micro-RNAs. Possible targets for intervention and drug development to manage distal consequences of infection with P. gingivalis are also reviewed.
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Affiliation(s)
- Abhishek Wadhawan
- Mood and Anxiety Program, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, United States.,Department of Psychiatry, Saint Elizabeths Hospital, Washington, D.C. 20032, United States
| | - Mark A Reynolds
- Department of Advanced Oral Sciences & Therapeutics, University of Maryland School of Dentistry, Baltimore 21201, United States
| | - Hina Makkar
- Mood and Anxiety Program, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, United States
| | - Alison J Scott
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, United States
| | - Eileen Potocki
- VA Maryland Healthcare System, Baltimore VA Medical Center, Baltimore, United States
| | - Andrew J Hoisington
- Air Force Institute of Technology, Wright-Patterson Air Force Base, United States
| | - Lisa A Brenner
- Departments of Psychiatry, Neurology, and Physical Medicine & Rehabilitation, University of Colorado Anschutz Medical Campus, Aurora, United States.,Rocky Mountain Mental Illness Research Education and Clinical Center (MIRECC), Veterans Integrated Service Network (VISN) 19, Aurora, United States.,Military and Veteran Microbiome: Consortium for Research and Education (MVM-CoRE), Aurora, United States
| | - Aline Dagdag
- Mood and Anxiety Program, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, United States
| | - Christopher A Lowry
- Departments of Psychiatry, Neurology, and Physical Medicine & Rehabilitation, University of Colorado Anschutz Medical Campus, Aurora, United States.,Rocky Mountain Mental Illness Research Education and Clinical Center (MIRECC), Veterans Integrated Service Network (VISN) 19, Aurora, United States.,Military and Veteran Microbiome: Consortium for Research and Education (MVM-CoRE), Aurora, United States.,Department of Integrative Physiology, Center for Neuroscience and Center for Microbial Exploration, University of Colorado Boulder, Boulder, United States.,Rocky Mountain Mental Illness Research Education and Clinical Center (MIRECC), Rocky Mountain Regional Veterans Affairs Medical Center (RMRVAMC), Aurora, United States
| | - Yogesh Dwivedi
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Alabama, United States
| | - Teodor T Postolache
- Mood and Anxiety Program, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, United States.,Rocky Mountain Mental Illness Research Education and Clinical Center (MIRECC), Veterans Integrated Service Network (VISN) 19, Aurora, United States.,Military and Veteran Microbiome: Consortium for Research and Education (MVM-CoRE), Aurora, United States.,Mental Illness Research, Education and Clinical Center (MIRECC), Veterans Integrated Service Network (VISN) 5, VA Capitol Health Care Network, Baltimore, United States
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5
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AlQranei MS, Senbanjo LT, Aljohani H, Hamza T, Chellaiah MA. Lipopolysaccharide- TLR-4 Axis regulates Osteoclastogenesis independent of RANKL/RANK signaling. BMC Immunol 2021; 22:23. [PMID: 33765924 PMCID: PMC7995782 DOI: 10.1186/s12865-021-00409-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 03/01/2021] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Lipopolysaccharide (LPS) is an endotoxin and a vital component of gram-negative bacteria's outer membrane. During gram-negative bacterial sepsis, LPS regulates osteoclast differentiation and activity, in addition to increasing inflammation. This study aimed to investigate how LPS regulates osteoclast differentiation of RAW 264.7 cells in vitro. RESULTS Herein, we revealed that RAW cells failed to differentiate into mature osteoclasts in vitro in the presence of LPS. However, differentiation occurred in cells primed with receptor activator of nuclear factor-kappa-Β ligand (RANKL) for 24 h and then treated with LPS for 48 h (henceforth, denoted as LPS-treated cells). In cells treated with either RANKL or LPS, an increase in membrane levels of toll-like receptor 4 (TLR4) receptor was observed. Mechanistically, an inhibitor of TLR4 (TAK-242) reduced the number of osteoclasts as well as the secretion of tumor necrosis factor (TNF)-α in LPS-treated cells. RANKL-induced RAW cells secreted a very basal level TNF-α. TAK-242 did not affect RANKL-induced osteoclastogenesis. Increased osteoclast differentiation in LPS-treated osteoclasts was not associated with the RANKL/RANK/OPG axis but connected with the LPS/TLR4/TNF-α tumor necrosis factor receptor (TNFR)-2 axis. We postulate that this is because TAK-242 and a TNF-α antibody suppress osteoclast differentiation. Furthermore, an antibody against TNF-α reduced membrane levels of TNFR-2. Secreted TNF-α appears to function as an autocrine/ paracrine factor in the induction of osteoclastogenesis independent of RANKL. CONCLUSION TNF-α secreted via LPS/TLR4 signaling regulates osteoclastogenesis in macrophages primed with RANKL and then treated with LPS. Our findings suggest that TLR4/TNF-α might be a potential target to suppress bone loss associated with inflammatory bone diseases, including periodontitis, rheumatoid arthritis, and osteoporosis.
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Affiliation(s)
- Mohammed S AlQranei
- Department of Oncology and Diagnostic Sciences, School of Dentistry, University of Maryland, 650 W Baltimore Street, Baltimore, MD, 21201, USA
- Preventive Dental Sciences Department, School of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Linda T Senbanjo
- Department of Oncology and Diagnostic Sciences, School of Dentistry, University of Maryland, 650 W Baltimore Street, Baltimore, MD, 21201, USA
| | - Hanan Aljohani
- Department of Oncology and Diagnostic Sciences, School of Dentistry, University of Maryland, 650 W Baltimore Street, Baltimore, MD, 21201, USA
- Department of Oral Medicine and Diagnostics Sciences, King Saud University, School of Dentistry, Riyadh, Kingdom of Saudi Arabia
| | - Therwa Hamza
- Department of Oncology and Diagnostic Sciences, School of Dentistry, University of Maryland, 650 W Baltimore Street, Baltimore, MD, 21201, USA
| | - Meenakshi A Chellaiah
- Department of Oncology and Diagnostic Sciences, School of Dentistry, University of Maryland, 650 W Baltimore Street, Baltimore, MD, 21201, USA.
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Endotoxin Translocation and Gut Inflammation Are Increased in Broiler Chickens Receiving an Oral Lipopolysaccharide (LPS) Bolus during Heat Stress. Toxins (Basel) 2020; 12:toxins12100622. [PMID: 33003423 PMCID: PMC7601408 DOI: 10.3390/toxins12100622] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 09/24/2020] [Accepted: 09/25/2020] [Indexed: 02/06/2023] Open
Abstract
Lipopolysaccharides (LPS), also termed endotoxins, are the major component of the outer membrane of Gram-negative bacteria. In general, endotoxins in the intestine are considered harmless in healthy animals. However, different stressors, such as heat stress, can lead to a compromised gut barrier, resulting in endotoxin translocation. Chickens are considered to be less sensitive to the effects of LPS compared with other species, for example, humans, pigs, or calves, probably because of the lack of the functional-specific TRAM-TRIF signalling pathway (MyD88-independent). Therefore, six LPS preparations (three different strains with two different preparation methods each) were compared in murine macrophages and characterized according to their MyD88-dependent pathway activation. All tested LPS preparations induced a strong inflammatory response after 4 and 24 h on a murine macrophage cell line. However, there was a similar strong response in the gene expression profile as well as production of nitrite oxide and TNF-alpha from LPS of different strains and preparation methods. On the basis of the results of the in vitro study, one LPS preparation was chosen for the subsequent in vivo study with broilers to assess the effect of an oral LPS bolus (E. coli O55:B5 phenol extracted; 2 mg/kg b.w.) during heat stress conditions (10 h, 36 °C). The most pronounced effects were seen in broilers receiving the oral LPS bolus during heat stress conditions. The endotoxin activity in the intestine as well as the serum concentration of the 3-OH C14 (part of LPS) were increased. In addition, an increased expression of genes related to inflammation and stress response (e.g., IL-6, IL-1beta, HSP70) was observed, whereas the expression of genes associated with gut health (e.g., MUC2, FABP2) was decreased. To conclude, an increase of intestinal LPS combined with heat stress can pose a risk to animal health.
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7
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Inaba H, Yoshida S, Nomura R, Kato Y, Asai F, Nakano K, Matsumoto-Nakano M. Porphyromonas gulae lipopolysaccharide elicits inflammatory responses through toll-like receptor 2 and 4 in human gingivalis epithelial cells. Cell Microbiol 2020; 22:e13254. [PMID: 32827217 DOI: 10.1111/cmi.13254] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 07/12/2020] [Accepted: 07/13/2020] [Indexed: 12/29/2022]
Abstract
Porphyromonas gulae, a Gram-negative black-pigmented anaerobe, has been associated with periodontal disease in companion animals and its virulence has been attributed to various factors, including lipopolysaccharide (LPS), protease and fimbriae. Toll-like receptors (TLRs) recognise pathogen-associated molecular patterns, such as peptidoglycan, lipids, lipoproteins, nucleic acid and LPS. Following P. gulae infection, some inflammatory responses are dependent on both TLR2 and TLR4. In addition, a recent clinical study revealed that acute and persistent inflammatory responses enhance the expressions of TLR2 and TLR4 in the oral cavity. In this study, we investigated the interaction between P. gulae LPS and human gingivalis epithelial cells (Ca9-22 cells). P. gulae LPS was found to increase TLR2 and TLR4 mRNA expressions and protein productions, and enhanced inflammatory responses, such as COX2 , TNF-ɑ, IL-6 and IL-8. Stimulated Ca9-22 cells exhibited phosphorylation of ERK1/2 and p38, and their inhibitors diminished inflammatory responses, while knockdown of the TLR2 and/or TLR4 genes with small interfering RNA (siRNA) prevented inflammatory responses. Moreover, p38 and ERK1/2 phosphorylation was decreased in TLR2 and TLR4 gene knockdown cells. These findings suggest that P. gulae LPS activates p38 and ERK1/2 via TLR2 and TLR4, leading to inflammatory responses in human gingival epithelial cells.
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Affiliation(s)
- Hiroaki Inaba
- Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Sho Yoshida
- Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Ryota Nomura
- Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - Yukio Kato
- Department of Veterinary Public Health II, School of Veterinary Medicine, Azabu University, Sagamihara, Japan
| | - Fumitoshi Asai
- Department of Pharmacology, School of Veterinary Medicine, Azabu University, Sagamihara, Japan
| | - Kazuhiko Nakano
- Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - Michiyo Matsumoto-Nakano
- Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
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8
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Response of Human Mesenchymal Stromal Cells from Periodontal Tissue to LPS Depends on the Purity but Not on the LPS Source. Mediators Inflamm 2020; 2020:8704896. [PMID: 32714091 PMCID: PMC7352132 DOI: 10.1155/2020/8704896] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 05/05/2020] [Accepted: 06/08/2020] [Indexed: 12/16/2022] Open
Abstract
Human periodontal ligament stromal cells (hPDLSCs) and gingival mesenchymal stromal cells (hGMSCs) are resident mesenchymal stromal cells (MSCs) of the periodontal tissue. The lipopolysaccharide (LPS) from Porphyromonas gingivalis is structurally distinct from that of other Gram-negative bacteria, and earlier studies linked this structural difference to a distinct virulence activity and the ability to activate toll-like receptor 2 (TLR-2), besides TLR-4 as commonly occurring upon LPS challenge. Later studies, in contrast, argue that TLR-2 activation by P. gingivalis LPS is due to lipoprotein contamination. In the present study, we aimed to define the influence of structure versus purity of P. gingivalis LPS on the immune response of hPDLSCs and hGMSCs. Cells were stimulated with commercially available "standard" P. gingivalis LPS, "ultrapure" P. gingivalis LPS, or "ultrapure" Escherichia coli LPS, and the expression of interleukin- (IL-) 8, IL-6, monocyte chemoattractant protein- (MCP-) 1, TLR-2, and TLR-4 was evaluated. The contribution of TLR-4 to the LPS-induced response was assessed using the specific TLR-4 inhibitor TAK-242. "Standard" P. gingivalis LPS induced significantly higher IL-8, IL-6, and MCP-1 production compared to the "ultrapure" LPS preparations, with no significant difference detectable for "ultrapure" LPS from P. gingivalis and E. coli. By using TAK-242, the response of hPDLSCs and hGMSCs to "ultrapure" LPS preparations was effectively inhibited to the levels comparable to those of nonstimulated controls. In contrast, high levels of response to "standard" LPS were observed, even in the presence of TAK-242. Our data show that the response of MSCs from periodontal tissue to LPS depends more on the purity of the LPS preparation than on the LPS source. Even a small amount of contaminating lipoproteins can drastically enhance the hPDLSCs' and hGMSCs; responsiveness to P. gingivalis LPS, which might also contribute to the progression of periodontal disease.
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9
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Osteoclastogenesis in periodontal diseases: Possible mediators and mechanisms. J Oral Biosci 2020; 62:123-130. [PMID: 32081710 DOI: 10.1016/j.job.2020.02.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 02/01/2020] [Accepted: 02/06/2020] [Indexed: 12/31/2022]
Abstract
BACKGROUND Periodontitis is the inflammation of the tooth-supporting structures and is one of the most common diseases of the oral cavity. The outcome of periodontal infections is tooth loss due to a lack of alveolar bone support. Osteoclasts are giant, multi-nucleated, and bone-resorbing cells that are central for many osteolytic diseases, including periodontitis. Receptor activator of nuclear factor-kB ligand (RANKL) is the principal factor involved in osteoclast differentiation, activation, and survival. However, under pathological conditions, a variety of pro-inflammatory cytokines secreted by activated immune cells also contribute to osteoclast differentiation and activity. Lipopolysaccharide (LPS) is a vital component of the outer membrane of the Gram-negative bacteria. It binds to the Toll-like receptors (TLRs) expressed in many cells and elicits an immune response. HIGHLIGHTS The presence of bacterial LPS in the periodontal area stimulates the secretion of RANKL as well as other inflammatory mediators, activating the process of osteoclastogenesis. RANKL, either independently or synergistically with LPS, can regulate osteoclastogenesis, while LPS alone cannot. MicroRNA, IL-22, M1/M2 macrophages, and memory B cells have recently been shown to modulate osteoclastogenesis in periodontal diseases. CONCLUSION In this review, we summarize the mechanism of osteoclastogenesis accompanying periodontal diseases at the cellular level. We discuss a) the effects of LPS/TLR signaling and other cytokines on RANKL-dependent and -independent mechanisms involved in osteoclastogenesis; b) the recently identified role of several endogenous factors such as miRNA, IL-22, M1/M2 macrophages, and memory B cells in regulating osteoclastogenesis during periodontal pathogenesis.
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Steimle A, Michaelis L, Di Lorenzo F, Kliem T, Münzner T, Maerz JK, Schäfer A, Lange A, Parusel R, Gronbach K, Fuchs K, Silipo A, Öz HH, Pichler BJ, Autenrieth IB, Molinaro A, Frick JS. Weak Agonistic LPS Restores Intestinal Immune Homeostasis. Mol Ther 2019; 27:1974-1991. [PMID: 31416777 PMCID: PMC6838991 DOI: 10.1016/j.ymthe.2019.07.007] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 06/27/2019] [Accepted: 07/08/2019] [Indexed: 02/07/2023] Open
Abstract
Generated by gram-negative bacteria, lipopolysaccharides (LPSs) are one of the most abundant and potent immunomodulatory substances present in the intestinal lumen. Interaction of agonistic LPS with the host myeloid-differentiation-2/Toll-like receptor 4 (MD-2/TLR4) receptor complex results in nuclear factor κB (NF-κB) activation, followed by the robust induction of pro-inflammatory immune responses. Here we have isolated LPS from a common gut commensal, Bacteroides vulgatus mpk (BVMPK), which provides only weak agonistic activity. This weak agonistic activity leads to the amelioration of inflammatory immune responses in a mouse model for experimental colitis, and it was in sharp contrast to strong agonists and antagonists. In this context, the administration of BVMPK LPS into mice with severe intestinal inflammation re-established intestinal immune homeostasis within only 2 weeks, resulting in the clearance of all symptoms of inflammation. These inflammation-reducing properties of weak agonistic LPS are grounded in the induction of a special type of endotoxin tolerance via the MD-2/TLR4 receptor complex axis in intestinal lamina propria CD11c+ cells. Thus, weak agonistic LPS represents a promising agent to treat diseases involving pathological overactivation of the intestinal immune system, e.g., in inflammatory bowel diseases.
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Affiliation(s)
- Alex Steimle
- Institute of Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany
| | - Lena Michaelis
- Institute of Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany
| | - Flaviana Di Lorenzo
- Department of Chemical Sciences, University of Naples Federico II, Naples, Italy
| | - Thorsten Kliem
- Institute of Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany
| | - Tobias Münzner
- Institute of Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany
| | - Jan Kevin Maerz
- Institute of Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany
| | - Andrea Schäfer
- Institute of Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany
| | - Anna Lange
- Institute of Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany
| | - Raphael Parusel
- Institute of Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany
| | - Kerstin Gronbach
- Institute of Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany
| | - Kerstin Fuchs
- Institute of Radiology, Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, University of Tübingen, Tübingen, Germany
| | - Alba Silipo
- Department of Chemical Sciences, University of Naples Federico II, Naples, Italy
| | - Hasan Halit Öz
- Institute of Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany
| | - Bernd J Pichler
- Institute of Radiology, Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, University of Tübingen, Tübingen, Germany
| | - Ingo B Autenrieth
- Institute of Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany
| | - Antonio Molinaro
- Department of Chemical Sciences, University of Naples Federico II, Naples, Italy
| | - Julia-Stefanie Frick
- Institute of Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany.
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11
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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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12
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Murdock JL, Núñez G. TLR4: The Winding Road to the Discovery of the LPS Receptor. THE JOURNAL OF IMMUNOLOGY 2018; 197:2561-2. [PMID: 27638937 DOI: 10.4049/jimmunol.1601400] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Jessica L Murdock
- Department of Pathology and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Gabriel Núñez
- Department of Pathology and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109
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13
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Garami A, Steiner AA, Romanovsky AA. Fever and hypothermia in systemic inflammation. HANDBOOK OF CLINICAL NEUROLOGY 2018; 157:565-597. [PMID: 30459026 DOI: 10.1016/b978-0-444-64074-1.00034-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Systemic inflammation-associated syndromes (e.g., sepsis and septic shock) often have high mortality and remain a challenge in emergency medicine. Systemic inflammation is usually accompanied by changes in body temperature: fever or hypothermia. In animal studies, systemic inflammation is often modeled by administering bacterial lipopolysaccharide, which triggers autonomic and behavioral thermoeffector responses and causes either fever or hypothermia, depending on the dose and ambient temperature. Fever and hypothermia are regulated changes of body temperature, which correspond to mild and severe forms of systemic inflammation, respectively. Mediators of fever and hypothermia are called endogenous pyrogens and cryogens; they are produced when the innate immune system recognizes an infectious pathogen. Upon an inflammatory challenge, hepatic and pulmonary macrophages (and later brain endothelial cells) start to release lipid mediators, of which prostaglandin (PG) E2 plays the key role, and cytokines. Blood PGE2 enters the brain and triggers fever. At later stages of fever, PGE2 synthesized within the blood-brain barrier maintains fever. In both cases, PGE2 is synthesized by cyclooxygenase-2 and microsomal PGE2synthase-1. Mediators of hypothermia are not well established. Both fever and hypothermia are beneficial host defense responses. Based on evidence from studies in laboratory animals and clinical trials in humans, fever is beneficial for fighting mild infection. Based mainly on animal studies, hypothermia is beneficial in severe systemic inflammation and infection.
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Affiliation(s)
- Andras Garami
- Institute for Translational Medicine, Medical School, University of Pécs, Pécs, Hungary.
| | - Alexandre A Steiner
- Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Andrej A Romanovsky
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, AZ, United States
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14
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Nativel B, Couret D, Giraud P, Meilhac O, d'Hellencourt CL, Viranaïcken W, Da Silva CR. Porphyromonas gingivalis lipopolysaccharides act exclusively through TLR4 with a resilience between mouse and human. Sci Rep 2017; 7:15789. [PMID: 29150625 PMCID: PMC5693985 DOI: 10.1038/s41598-017-16190-y] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 11/03/2017] [Indexed: 02/06/2023] Open
Abstract
Porphyromonas gingivalis is a key bacterium in chronic periodontitis, which is associated with several chronic inflammatory diseases. Lipopolysaccharides from P. gingivalis (Pg LPS) can activate multiple cell types via the production of pro-inflammatory cytokines. The receptors for Pg LPS have initially been reported as TLR2, contrasting with the well-studied TLR4 receptor for E. coli LPS; this observation remains controversial since synthetic Pg lipid A activates TLR4 but not TLR2. Despite this observation, the dogma of Pg LPS-mediated TLR2 activation remains the basis of many hypotheses and result interpretations. In the present work, we aimed at determining whether TLR4 or TLR2, or both, mediate Pg LPS pro-inflammatory activity using Pg LPS with different grades of purity, instead of synthetic lipid A from Pg LPS. Here we show that Pg LPS 1) acts exclusively through TLR4, and 2) are differently recognized by mouse and human TLR4 both in vitro and in vivo. Taken together, our results suggest that Pg LPS activity is mediated exclusively through TLR4 and only weakly induces proinflammatory cytokine secretion in mouse models. Caution should be taken when extrapolating data from mouse systems exposed to Pg or Pg LPS to humans.
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Affiliation(s)
- Brice Nativel
- Université de La Réunion, INSERM, UMR 1188 Diabète athérothombose Thérapies Réunion Océan Indien (DéTROI), Saint-Denis de La Réunion, France
| | - David Couret
- Université de La Réunion, INSERM, UMR 1188 Diabète athérothombose Thérapies Réunion Océan Indien (DéTROI), Saint-Denis de La Réunion, France.,CHU de La Réunion, Unité de soins intensifs neurologiques, Saint Pierre de La Réunion, France
| | - Pierre Giraud
- Université de La Réunion, INSERM, UMR 1188 Diabète athérothombose Thérapies Réunion Océan Indien (DéTROI), Saint-Denis de La Réunion, France
| | - Olivier Meilhac
- Université de La Réunion, INSERM, UMR 1188 Diabète athérothombose Thérapies Réunion Océan Indien (DéTROI), Saint-Denis de La Réunion, France
| | - Christian Lefebvre d'Hellencourt
- Université de La Réunion, INSERM, UMR 1188 Diabète athérothombose Thérapies Réunion Océan Indien (DéTROI), Saint-Denis de La Réunion, France
| | - Wildriss Viranaïcken
- Université de La Réunion, CNRS UMR9192, INSERM U1187, IRD UMR249, Unité Mixte Processus Infectieux en Milieu Insulaire Tropical (PIMIT), Plateforme Technologique CYROI, Sainte-Clotilde, La Réunion, France.
| | - Christine Robert Da Silva
- Université de La Réunion, INSERM, UMR 1188 Diabète athérothombose Thérapies Réunion Océan Indien (DéTROI), Saint-Denis de La Réunion, France.
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15
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Yang QL, Shen JQ, Jiang ZH, Shi YL, Wan XL, Yang YC. TLR2 signal influences the iNOS/NO responses and worm development in C57BL/6J mice infected with Clonorchis sinensis. Parasit Vectors 2017; 10:379. [PMID: 28784165 PMCID: PMC5547496 DOI: 10.1186/s13071-017-2318-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 08/01/2017] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Although the responses of inducible nitric oxide synthase (iNOS) and associated cytokine after Clonorchis sinensis infection have been studied recently, their mechanisms remain incompletely understood. In this study, we investigated the effects of toll-like receptor 2 (TLR2) signals on iNOS/nitric oxide (NO) responses after C. sinensis infection. We also evaluated the correlations between iNOS responses and worm development, which are possibly regulated by TLR2 signal. METHODS TLR2 wild-type and mutant C57BL/6 J mice were infected with 60 C. sinensis metacercariae, and the samples were collected at 30, 60, 90 and 120 days post-infection (dpi). The total serum NO levels were detected using Griess reagent after nitrate was reduced to nitrite. Hepatic tissue samples from the infected mice were sliced and stained with hematoxylin and eosin (HE) to observe worm development in the intrahepatic bile ducts. The iNOS mRNA transcripts in the splenocytes were examined by real time reverse transcriptase polymerase chain reaction (qRT-PCR), and iNOS expression was detected by immunohistochemistry. RESULTS Developing C. sinensis juvenile worms were more abundant in the intrahepatic bile ducts of TLR2 mutant mice than those of TLR2 wild-type mice. However, no eggs were found in the faeces of both mice samples. The serum levels of total NO significantly increased in TLR2 mutant mice infected with C. sinensis at 30 (t (5) = 2.595, P = 0.049), 60 (t (5) = 7.838, P = 0.001) and 90 dpi (t (5) = 3.032, P = 0.029). Meanwhile, no changes occurred in TLR2 wild-type mice compared with uninfected controls during the experiment. The iNOS expression in splenocytes showed unexpected higher background levels in TLR2 mutant mice than those in TLR2 wild-type mice. Furthermore, the iNOS mRNA transcripts in splenocytes were significantly increased in the TLR2 wild-type mice infected with C. sinensis at 30 (t (5) = 5.139, P = 0.004), 60 (t (5) = 6.138, P = 0.002) and 90 dpi (t (5) = 6.332, P = 0.001). However, the rising of iNOS transcripts dropped under the uninfected control level in the TLR2 mutant mice at 120 dpi (t (5) = -9.082, P < 0.0001). Both total NO and iNOS transcripts were significantly higher in the TLR2 mutant mice than those in the TLR2 wild-type mice at 30 (t (5) = 3.091/2.933, P = 0.027/0.033) and 60 dpi (t (5) = 2.667/6.331, P = 0.044/0.001), respectively. In addition, the remarkable increase of iNOS expressions was immunohistochemically detected in the splenic serial sections of TLR2 wild-type mice at 30 and 60 dpi. However, the expressions of iNOS were remarkably decreased in the splenocytes of both TLR2 wild-type and mutant mice at 120 dpi. CONCLUSIONS These results demonstrate that TLR2 signal plays an important role in the regulation of iNOS expression after C. sinensis infection. TLR2 signal is also beneficial to limiting worm growth and development and contributing to the susceptibility to C. sinensis in which the iNOS/NO reactions possibly participate.
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Affiliation(s)
- Qing-Li Yang
- Guangxi Key Laboratory for Viral Hepatitis Prevention and Control, Guangxi Zhuang Autonomous Region Center for Disease Prevention and Control, Nanning, 530028 Guangxi People’s Republic of China
| | - Ji-Qing Shen
- Department of Parasitology, Guangxi Medical University, Nanning, 530021 Guangxi People’s Republic of China
| | - Zhi-Hua Jiang
- Guangxi Key Laboratory for Viral Hepatitis Prevention and Control, Guangxi Zhuang Autonomous Region Center for Disease Prevention and Control, Nanning, 530028 Guangxi People’s Republic of China
| | - Yun-Liang Shi
- Guangxi Key Laboratory for Viral Hepatitis Prevention and Control, Guangxi Zhuang Autonomous Region Center for Disease Prevention and Control, Nanning, 530028 Guangxi People’s Republic of China
| | - Xiao-Ling Wan
- Guangxi Key Laboratory for Viral Hepatitis Prevention and Control, Guangxi Zhuang Autonomous Region Center for Disease Prevention and Control, Nanning, 530028 Guangxi People’s Republic of China
| | - Yi-Chao Yang
- Guangxi Key Laboratory for Viral Hepatitis Prevention and Control, Guangxi Zhuang Autonomous Region Center for Disease Prevention and Control, Nanning, 530028 Guangxi People’s Republic of China
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16
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Hashimoto M, Waki J, Nakayama-Imaohji H, Ozono M, Hashiguchi S, Kuwahara T. TLR2-stimulating contaminants in glycoconjugate fractions prepared from Bacteroides fragilis. Innate Immun 2017; 23:449-458. [PMID: 28606014 DOI: 10.1177/1753425917714313] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Bacteroides fragilis is a member of the normal intestinal flora and is involved in host immunostimulation via TLR2. On the bacterial cell surface, glycoconjugates, such as LPS and capsular polysaccharide A (PSA), have been reported to participate in host immunostimulation via TLR2. Previously, we identified a TLR2-stimulating lipoprotein in B. fragilis cells. In this study, we demonstrated that TLR2-stimulating principal molecules in glycoconjugate fractions prepared from B. fragilis are contaminating proteinous molecules, which may also be lipoproteins. The glycoconjugate fractions were prepared by phenol-hot water extraction of B. fragilis wild type and PSA-deficient strains, followed by hydrophobic interaction chromatography. TLR2-stimilating activities of the fractions were not affected by PSA deficiency. By in-gel TLR2-stimulation assay, molecules in high-molecular-mass area, where capsular polysaccharides were migrated, were found not to stimulate TLR2, but those in the range of 15-40 kDa were active. Further, proteinase K could digest the latter molecules and the TLR2-stimulating activities were migrated to the area of below 15 kDa. These results support that proteinous molecules, which are estimated to be lipoproteins, are responsible for almost all TLR2-stimulating activity in the glycoconjugate fractions prepared from B. fragilis.
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Affiliation(s)
- Masahito Hashimoto
- 1 Department of Chemistry, Biotechnology, and Chemical Engineering, Kagoshima University, Kagoshima, Japan
| | - Junpei Waki
- 1 Department of Chemistry, Biotechnology, and Chemical Engineering, Kagoshima University, Kagoshima, Japan
| | | | - Mami Ozono
- 1 Department of Chemistry, Biotechnology, and Chemical Engineering, Kagoshima University, Kagoshima, Japan
| | - Shuhei Hashiguchi
- 1 Department of Chemistry, Biotechnology, and Chemical Engineering, Kagoshima University, Kagoshima, Japan
| | - Tomomi Kuwahara
- 2 Department of Microbiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
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17
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Battin C, Hennig A, Mayrhofer P, Kunert R, Zlabinger GJ, Steinberger P, Paster W. A human monocytic NF-κB fluorescent reporter cell line for detection of microbial contaminants in biological samples. PLoS One 2017; 12:e0178220. [PMID: 28542462 PMCID: PMC5443541 DOI: 10.1371/journal.pone.0178220] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 05/09/2017] [Indexed: 12/16/2022] Open
Abstract
Sensing of pathogens by innate immune cells is essential for the initiation of appropriate immune responses. Toll-like receptors (TLRs), which are highly sensitive for various structurally and evolutionary conserved molecules derived from microbes have a prominent role in this process. TLR engagement results in the activation of the transcription factor NF-κB, which induces the expression of cytokines and other inflammatory mediators. The exquisite sensitivity of TLR signalling can be exploited for the detection of bacteria and microbial contaminants in tissue cultures and in protein preparations. Here we describe a cellular reporter system for the detection of TLR ligands in biological samples. The well-characterized human monocytic THP-1 cell line was chosen as host for an NF-ᴋB-inducible enhanced green fluorescent protein reporter gene. We studied the sensitivity of the resultant reporter cells for a variety of microbial components and observed a strong reactivity towards TLR1/2 and TLR2/6 ligands. Mycoplasma lipoproteins are potent TLR2/6 agonists and we demonstrate that our reporter cells can be used as reliable and robust detection system for mycoplasma contaminations in cell cultures. In addition, a TLR4-sensitive subline of our reporters was engineered, and probed with recombinant proteins expressed in different host systems. Bacterially expressed but not mammalian expressed proteins induced strong reporter activity. We also tested proteins expressed in an E. coli strain engineered to lack TLR4 agonists. Such preparations also induced reporter activation in THP-1 cells highlighting the importance of testing recombinant protein preparations for microbial contaminations beyond endotoxins. Our results demonstrate the usefulness of monocytic reporter cells for high-throughput screening for microbial contaminations in diverse biological samples, including tissue culture supernatants and recombinant protein preparations. Fluorescent reporter assays can be measured on standard flow cytometers and in contrast to established detection methods, like luciferase-based systems or Limulus Amebocyte Lysate tests, they do not require costly reagents.
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Affiliation(s)
- Claire Battin
- Division of Immune Receptors and T Cell Activation, Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Annika Hennig
- Division of Immune Receptors and T Cell Activation, Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Patrick Mayrhofer
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Renate Kunert
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Gerhard J. Zlabinger
- Division of Clinical and Experimental Immunology, Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Peter Steinberger
- Division of Immune Receptors and T Cell Activation, Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
- * E-mail: (PS); (WP), (WP)
| | - Wolfgang Paster
- Division of Immune Receptors and T Cell Activation, Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
- * E-mail: (PS); (WP), (WP)
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18
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Characterization of host responses induced by Toll-like receptor ligands in chicken cecal tonsil cells. Vet Immunol Immunopathol 2016; 174:19-25. [PMID: 27185259 DOI: 10.1016/j.vetimm.2016.04.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 03/25/2016] [Accepted: 04/04/2016] [Indexed: 11/22/2022]
Abstract
The innate responses of cecal tonsils against invading microorganisms are mediated by conserved pattern recognition receptors (PRRs) such as the Toll-like receptors (TLRs). TLRs expressed by mammalian and avian immune system cells have the capability to recognize pathogen-associated molecular patterns (PAMPs). Although, the role of TLR ligands in innate and adaptive responses in chickens has been characterized in spleen and bursa of Fabricius, considerably less is known about responses in cecal tonsils. The aim of the current study was to assess responses of mononuclear cells from cecal tonsils to treatment with the TLR2, TLR4 and TLR21 ligands, Pam3CSK4, lipopolysaccharide (LPS), and CpG oligodeoxynucleotide (ODN), respectively. All three ligands induced significant up-regulation of interferon (IFN)-γ, interleukin (IL)-1β, IL-6 and CxCLi2/IL-8, whereas no significant changes were observed in expression of IL-13 or the antimicrobial peptides, avian β-defensin (AvBD) 1, AvBD2 and cathelicidin 3 (CATHL-3). In general, CpG ODN elicited the highest cytokine responses by cecal tonsil mononuclear cells, inducing significantly higher expression compared to LPS and Pam3CSK4, for IFNγ, IL-1β, IL-6 and CxCLi2 at various time points. These findings suggest the potential use of TLR21 ligands as mucosal vaccine adjuvants, especially in the context of pathogens of the intestinal tract.
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19
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Weehuizen TAF, Prior JL, van der Vaart TW, Ngugi SA, Nepogodiev SA, Field RA, Kager LM, van ‘t Veer C, de Vos AF, Wiersinga WJ. Differential Toll-Like Receptor-Signalling of Burkholderia pseudomallei Lipopolysaccharide in Murine and Human Models. PLoS One 2015; 10:e0145397. [PMID: 26689559 PMCID: PMC4687033 DOI: 10.1371/journal.pone.0145397] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 12/03/2015] [Indexed: 11/19/2022] Open
Abstract
The Gram-negative bacterium Burkholderia pseudomallei causes melioidosis and is a CDC category B bioterrorism agent. Toll-like receptor (TLR)-2 impairs host defense during pulmonary B.pseudomallei infection while TLR4 only has limited impact. We investigated the role of TLRs in B.pseudomallei-lipopolysaccharide (LPS) induced inflammation. Purified B.pseudomallei-LPS activated only TLR2-transfected-HEK-cells during short stimulation but both HEK-TLR2 and HEK-TLR4-cells after 24 h. In human blood, an additive effect of TLR2 on TLR4-mediated signalling induced by B.pseudomallei-LPS was observed. In contrast, murine peritoneal macrophages recognized B.pseudomallei-LPS solely through TLR4. Intranasal inoculation of B.pseudomallei-LPS showed that both TLR4-knockout(-/-) and TLR2x4-/-, but not TLR2-/- mice, displayed diminished cytokine responses and neutrophil influx compared to wild-type controls. These data suggest that B.pseudomallei-LPS signalling occurs solely through murine TLR4, while in human models TLR2 plays an additional role, highlighting important differences between specificity of human and murine models that may have important consequences for B.pseudomallei-LPS sensing by TLRs and subsequent susceptibility to melioidosis.
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Affiliation(s)
- Tassili A. F. Weehuizen
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
- * E-mail: (TAFW); (WJW)
| | - Joann L. Prior
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Thomas W. van der Vaart
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
| | - Sarah A. Ngugi
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | | | - Robert A. Field
- John Innes Centre, Norwich Research Park, Colney, United Kingdom
| | - Liesbeth M. Kager
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
| | - Cornelis van ‘t Veer
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
| | - Alex F. de Vos
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
| | - W. Joost Wiersinga
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
- Department of Internal Medicine, Division of Infectious Diseases, Academic Medical Center, Amsterdam, the Netherlands
- * E-mail: (TAFW); (WJW)
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20
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Villarino Romero R, Hasan S, Faé K, Holubova J, Geurtsen J, Schwarzer M, Wiertsema S, Osicka R, Poolman J, Sebo P. Bordetella pertussis filamentous hemagglutinin itself does not trigger anti-inflammatory interleukin-10 production by human dendritic cells. Int J Med Microbiol 2015; 306:38-47. [PMID: 26699834 DOI: 10.1016/j.ijmm.2015.11.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 10/30/2015] [Accepted: 11/24/2015] [Indexed: 01/12/2023] Open
Abstract
Filamentous hemagglutinin (FHA) is an important adhesin of the whooping cough agent Bordetella pertussis and is contained in most acellular pertussis vaccines. Recently, FHA was proposed to exert an immunomodulatory activity through induction of tolerogenic IL-10 secretion from dendritic cells. We have re-evaluated the cytokine-inducing activity of FHA, placing specific emphasis on the role of the residual endotoxin contamination of FHA preparations. We show that endotoxin depletion did not affect the capacity of FHA to bind primary human monocyte-derived dendritic cells, while it abrogated the capacity of FHA to elicit TNF-α and IL-10 secretion and strongly reduced its capacity to trigger IL-6 production. The levels of cytokines induced by the different FHA preparations correlated with their residual contents of B. pertussis endotoxin. Moreover, FHA failed to trigger cytokine secretion in the presence of antibodies that block TLR2 and/or TLR4 signaling. The TLR2 signaling capacity appeared to be linked to the presence of endotoxin-associated components in FHA preparations and not to the FHA protein itself. These results show that the endotoxin-depleted FHA protein does not induce cytokine release from human dendritic cells.
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Affiliation(s)
- Rodrigo Villarino Romero
- Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Videnska 1083, 142 20 Prague, Czech Republic
| | - Shakir Hasan
- Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Videnska 1083, 142 20 Prague, Czech Republic
| | - Kellen Faé
- Bacterial Vaccine Discovery & Early Development, Janssen, Archimedesweg 4-6, 2333 CN Leiden, The Netherlands
| | - Jana Holubova
- Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Videnska 1083, 142 20 Prague, Czech Republic
| | - Jeroen Geurtsen
- Bacterial Vaccine Discovery & Early Development, Janssen, Archimedesweg 4-6, 2333 CN Leiden, The Netherlands
| | - Martin Schwarzer
- Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Videnska 1083, 142 20 Prague, Czech Republic
| | - Selma Wiertsema
- Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Videnska 1083, 142 20 Prague, Czech Republic
| | - Radim Osicka
- Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Videnska 1083, 142 20 Prague, Czech Republic
| | - Jan Poolman
- Bacterial Vaccine Discovery & Early Development, Janssen, Archimedesweg 4-6, 2333 CN Leiden, The Netherlands
| | - Peter Sebo
- Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Videnska 1083, 142 20 Prague, Czech Republic.
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21
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Bryant CE, Orr S, Ferguson B, Symmons MF, Boyle JP, Monie TP. International Union of Basic and Clinical Pharmacology. XCVI. Pattern recognition receptors in health and disease. Pharmacol Rev 2015; 67:462-504. [PMID: 25829385 DOI: 10.1124/pr.114.009928] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Since the discovery of Toll, in the fruit fly Drosophila melanogaster, as the first described pattern recognition receptor (PRR) in 1996, many families of these receptors have been discovered and characterized. PRRs play critically important roles in pathogen recognition to initiate innate immune responses that ultimately link to the generation of adaptive immunity. Activation of PRRs leads to the induction of immune and inflammatory genes, including proinflammatory cytokines and chemokines. It is increasingly clear that many PRRs are linked to a range of inflammatory, infectious, immune, and chronic degenerative diseases. Several drugs to modulate PRR activity are already in clinical trials and many more are likely to appear in the near future. Here, we review the different families of mammalian PRRs, the ligands they recognize, the mechanisms of activation, their role in disease, and the potential of targeting these proteins to develop the anti-inflammatory therapeutics of the future.
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Affiliation(s)
- Clare E Bryant
- Departments of Veterinary Medicine (C.E.B., J.P.B., T.P.M.), Pathology (B.F.), and Biochemistry (M.F.S., J.P.B.), University of Cambridge, Cambridge, United Kingdom; and Institute of Infection and Immunity, Cardiff University, Cardiff, United Kingdom (S.O.)
| | - Selinda Orr
- Departments of Veterinary Medicine (C.E.B., J.P.B., T.P.M.), Pathology (B.F.), and Biochemistry (M.F.S., J.P.B.), University of Cambridge, Cambridge, United Kingdom; and Institute of Infection and Immunity, Cardiff University, Cardiff, United Kingdom (S.O.)
| | - Brian Ferguson
- Departments of Veterinary Medicine (C.E.B., J.P.B., T.P.M.), Pathology (B.F.), and Biochemistry (M.F.S., J.P.B.), University of Cambridge, Cambridge, United Kingdom; and Institute of Infection and Immunity, Cardiff University, Cardiff, United Kingdom (S.O.)
| | - Martyn F Symmons
- Departments of Veterinary Medicine (C.E.B., J.P.B., T.P.M.), Pathology (B.F.), and Biochemistry (M.F.S., J.P.B.), University of Cambridge, Cambridge, United Kingdom; and Institute of Infection and Immunity, Cardiff University, Cardiff, United Kingdom (S.O.)
| | - Joseph P Boyle
- Departments of Veterinary Medicine (C.E.B., J.P.B., T.P.M.), Pathology (B.F.), and Biochemistry (M.F.S., J.P.B.), University of Cambridge, Cambridge, United Kingdom; and Institute of Infection and Immunity, Cardiff University, Cardiff, United Kingdom (S.O.)
| | - Tom P Monie
- Departments of Veterinary Medicine (C.E.B., J.P.B., T.P.M.), Pathology (B.F.), and Biochemistry (M.F.S., J.P.B.), University of Cambridge, Cambridge, United Kingdom; and Institute of Infection and Immunity, Cardiff University, Cardiff, United Kingdom (S.O.)
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22
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Nijland R, Hofland T, van Strijp JAG. Recognition of LPS by TLR4: potential for anti-inflammatory therapies. Mar Drugs 2014; 12:4260-73. [PMID: 25056632 PMCID: PMC4113827 DOI: 10.3390/md12074260] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 06/10/2014] [Accepted: 07/04/2014] [Indexed: 12/29/2022] Open
Abstract
LPS molecules of marine bacteria show structures distinct from terrestrial bacteria, due to the different environment that marine bacteria live in. Because of these different structures, lipid A molecules from marine bacteria are most often poor stimulators of the Toll-like receptor 4 (TLR4) pathway. Due to their low stimulatory potential, these lipid A molecules are suggested to be applicable as antagonists of TLR4 signaling in sepsis patients, where this immune response is amplified and unregulated. Antagonizing lipid A molecules might be used for future therapies against sepsis, therapies that currently do not exist. In this review, we will discuss these differences in lipid A structures and their recognition by the immune system. The modifications present in marine lipid A structures are described, and their potential as LPS antagonists will be discussed. Finally, since clinical trials built on antagonizing lipid A molecules have proven unsuccessful, we propose to also focus on different aspects of the TLR4 signaling pathway when searching for new potential drugs. Furthermore, we put forward the notion that bacteria probably already produce inhibitors of TLR4 signaling, making these bacterial products interesting molecules to investigate for future sepsis therapies.
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Affiliation(s)
- Reindert Nijland
- Medical Microbiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
| | - Tom Hofland
- Medical Microbiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
| | - Jos A G van Strijp
- Medical Microbiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
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23
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Verbeek RE, Siersema PD, Ten Kate FJ, Fluiter K, Souza RF, Vleggaar FP, Bus P, van Baal JWPM. Toll-like receptor 4 activation in Barrett's esophagus results in a strong increase in COX-2 expression. J Gastroenterol 2014; 49:1121-34. [PMID: 23955118 DOI: 10.1007/s00535-013-0862-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 07/19/2013] [Indexed: 02/04/2023]
Abstract
BACKGROUND Barrett's esophagus (BE) is known to progress to esophageal adenocarcinoma in a setting of chronic inflammation. Toll-like receptor (TLR) 4 has been linked to inflammation-associated carcinogenesis. We aimed to determine the expression and functional activity of TLR4 in the esophagus and whether TLR4 activation in BE could promote carcinogenesis by inducing COX-2 expression. METHODS TLR4 expression in esophageal adenocarcinoma, BE, duodenum, reflux esophagitis and normal squamous esophagus biopsies was assessed using real-time PCR and validated by in situ hybridization and immunohistochemistry. Ex vivo cultures of BE, duodenum and normal squamous esophagus biopsies and a BE cell line (BAR-T) were stimulated with the TLR4 agonist lipopolysaccharide (LPS). To evaluate the effect of TLR4 activation, NF-κB activation, IL8 secretion and expression and COX-2 expression were determined. RESULTS TLR4 expression was significantly increased in esophageal adenocarcinoma, BE, duodenum and reflux esophagitis compared to normal squamous esophagus. LPS stimulation resulted in NF-κB activation and a dose-dependent increase of IL8 secretion and mRNA expression. The induction of IL8 was more evident in BE compared to normal squamous esophagus. Upon LPS stimulation, COX-2 expression increased significantly in ex vivo cultured BE biopsies, which was observed in both epithelium and lamina propria cells. However, no effect was found in duodenum and normal squamous esophagus biopsies. CONCLUSION TLR4 activation in BE results in a strong increase in COX-2 and may contribute to malignant transformation.
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Affiliation(s)
- Romy E Verbeek
- Department of Gastroenterology and Hepatology (F02.618), University Medical Center Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands,
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Basto AP, Morais J, Marcelino E, Leitão A, Santos DM. An efficient depyrogenation method for recombinant bacterial outer membrane lipoproteins. Protein Expr Purif 2014; 98:10-7. [DOI: 10.1016/j.pep.2014.02.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 02/18/2014] [Accepted: 02/21/2014] [Indexed: 12/13/2022]
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Bordetella pertussis proteins dominating the major histocompatibility complex class II-presented epitope repertoire in human monocyte-derived dendritic cells. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2014; 21:641-50. [PMID: 24599530 DOI: 10.1128/cvi.00665-13] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Knowledge of naturally processed Bordetella pertussis-specific T cell epitopes may help to increase our understanding of the basis of cell-mediated immune mechanisms to control this reemerging pathogen. Here, we elucidate for the first time the dominant major histocompatibility complex (MHC) class II-presented B. pertussis CD4(+) T cell epitopes, expressed on human monocyte-derived dendritic cells (MDDC) after the processing of whole bacterial cells by use of a platform of immunoproteomics technology. Pertussis epitopes identified in the context of HLA-DR molecules were derived from two envelope proteins, i.e., putative periplasmic protein (PPP) and putative peptidoglycan-associated lipoprotein (PAL), and from two cytosolic proteins, i.e., 10-kDa chaperonin groES protein (groES) and adenylosuccinate synthetase (ASS). No epitopes were detectable from known virulence factors. CD4(+) T cell responsiveness in healthy adults against peptide pools representing epitope regions or full proteins confirmed the immunogenicity of PAL, PPP, groES, and ASS. Elevated lymphoproliferative activity to PPP, groES, and ASS in subjects within a year after the diagnosis of symptomatic pertussis suggested immunogenic exposure to these proteins during clinical infection. The PAL-, PPP-, groES-, and ASS-specific responses were associated with secretion of functional Th1 (tumor necrosis factor alpha [TNF-α] and gamma interferon [IFN-γ]) and Th2 (interleukin 5 [IL-5] and IL-13) cytokines. Relative paucity in the natural B. pertussis epitope display of MDDC, not dominated by epitopes from known protective antigens, can interfere with the effectiveness of immune recognition of B. pertussis. A more complete understanding of hallmarks in B. pertussis-specific immunity may advance the design of novel immunological assays and prevention strategies.
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Hashimoto M, Obara K, Ozono M, Furuyashiki M, Ikeda T, Suda Y, Fukase K, Fujimoto Y, Shigehisa H. Separation and characterization of the immunostimulatory components in unpolished rice black vinegar (kurozu). J Biosci Bioeng 2013; 116:688-96. [DOI: 10.1016/j.jbiosc.2013.05.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 04/27/2013] [Accepted: 05/22/2013] [Indexed: 01/15/2023]
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Herath TDK, Darveau RP, Seneviratne CJ, Wang CY, Wang Y, Jin L. Tetra- and penta-acylated lipid A structures of Porphyromonas gingivalis LPS differentially activate TLR4-mediated NF-κB signal transduction cascade and immuno-inflammatory response in human gingival fibroblasts. PLoS One 2013; 8:e58496. [PMID: 23554896 PMCID: PMC3595299 DOI: 10.1371/journal.pone.0058496] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 02/05/2013] [Indexed: 12/21/2022] Open
Abstract
Background Porphyromonas gingivalis is a major pathogen of periodontal disease that affects a majority of adults worldwide. Increasing evidence shows that periodontal disease is linked to various systemic diseases like diabetes and cardiovascular disease, by contributing to increased systemic levels of inflammation. Lipopolysaccharides (LPS), as a key virulent attribute of P. gingivalis, possesses significant amount of lipid A heterogeneity containing tetra- (LPS1435/1449) and penta-acylated (LPS1690) structures. Hitherto, the exact molecular mechanism of P. gingivalis LPS involved in periodontal pathogenesis remains unclear, due to limited understanding of the specific receptors and signaling pathways involved in LPS-host cell interactions. Methodology/Principal Findings This study systematically investigated the effects of P. gingivalis LPS1435/1449 and LPS1690 on the expression of TLR2 and TLR4 signal transduction and the activation of pro-inflammatory cytokines IL-6 and IL-8 in human gingival fibroblasts (HGFs). We found that LPS1435/1449 and LPS1690 differentially modulated TLR2 and TLR4 expression. NF-κB pathway was significantly activated by LPS1690 but not by LPS1435/1449. In addition, LPS1690 induced significant expression of NF-κB and p38 MPAK pathways-related genes, such as NFKBIA, NFKB1, IKBKB, MAP2K4 and MAPK8. Notably, the pro-inflammatory genes including GM-CSF, CXCL10, G-CSF, IL-6, IL-8 and CCL2 were significantly upregulated by LPS1690 while down-regulated by LPS1435/1449. Blocking assays confirmed that TLR4-mediated NF-κB signaling was vital in LPS1690-induced expression of IL-6 and IL-8 in HGFs. Conclusions/Significance The present study suggests that the tetra- and penta-acylated lipid A structures of P. gingivalis LPS differentially activate TLR4-mediated NF-κB signaling pathway, and significantly modulate the expression of IL-6 and IL-8 in HGFs. The ability to alter the lipid A structure of LPS could be one of the strategies carried-out by P. gingivalis to evade innate host defense in gingival tissues, thereby contributing to periodontal pathogenesis.
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Affiliation(s)
- Thanuja D. K. Herath
- Faculty of Dentistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Richard P. Darveau
- School of Dentistry, University of Washington, Seattle, Washington, United States of America
| | - Chaminda J. Seneviratne
- Faculty of Dentistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Cun-Yu Wang
- School of Dentistry, University of California Los Angeles, Los Angeles, California, United States of America
| | - Yu Wang
- Department of Pharmacology & Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Lijian Jin
- Faculty of Dentistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
- * E-mail:
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A novel class of lipoprotein lipase-sensitive molecules mediates Toll-like receptor 2 activation by Porphyromonas gingivalis. Infect Immun 2013; 81:1277-86. [PMID: 23381996 DOI: 10.1128/iai.01036-12] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Infection by the chronic periodontitis-associated pathogen Porphyromonas gingivalis activates a Toll-like receptor 2 (TLR2) response that triggers inflammation in the host but also promotes bacterial persistence. Our aim was to define ligands on the surfaces of intact P. gingivalis cells that determine its ability to activate TLR2. Molecules previously reported as TLR2 agonists include lipopolysaccharide (LPS), fimbriae, the lipoprotein PG1828, and phosphoceramides. We demonstrate that these molecules do not comprise the major factors responsible for stimulating TLR2 by whole bacterial cells. First, P. gingivalis mutants devoid of the reported protein agonists, PG1828 and fimbriae, activate TLR2 as strongly as the wild type. Second, two-phase extraction of whole bacteria resulted in a preponderance of TLR2 agonist activity partitioning to the hydrophilic phase, demonstrating that phosphoceramides are not a major TLR2 ligand. Third, analysis of LPS revealed that TLR2 activation is independent of lipid A structural variants. Instead, activation of TLR2 and TLR2/TLR1 by LPS is in large part due to copurifying molecules that are sensitive to the action of the enzyme lipoprotein lipase. Strikingly, intact P. gingivalis bacterial cells treated with lipoprotein lipase were attenuated in their ability to activate TLR2. We propose that a novel class of molecules comprised by lipoproteins constitutes the major determinants that confer to P. gingivalis the ability to stimulate TLR2 signaling.
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Identification of a TLR2-stimulating lipoprotein in Bacteroides fragilis JCM 11019 (NCTC 9343). Innate Immun 2012; 19:132-9. [DOI: 10.1177/1753425912454179] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Bacteroides fragilis is found among the normal intestinal flora and is involved in host immunostimulation via TLR2. Its cell surface components, such as LPS and capsular polysaccharides, were reported to participate in host immunostimulation. In this study, we report on the existence of a lipoprotein that acts as a TLR2 stimulant in B. fragilis. The TLR2-stimulating lipoprotein was obtained using Triton X-114-water phase partitioning followed by preparative SDS-PAGE. Its N-terminal hydrophobic peptide, which was separated from a tryptic digest, was characterized as a triacylated lipopeptide, and the lipoprotein was identified as BF1333 by mass spectrometry of Asp-N-digested peptides. These results showed that the lipoprotein acts as a TLR2-stimulating component in B. fragilis.
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Cai MS, Li ML, Zheng CF. Herpesviral infection and Toll-like receptor 2. Protein Cell 2012; 3:590-601. [PMID: 22865347 DOI: 10.1007/s13238-012-2059-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 07/02/2012] [Indexed: 12/24/2022] Open
Abstract
In the last decade, substantial progress has been made in understanding the molecular mechanisms involved in the initial host responses to viral infections. Herpesviral infections can provoke an inflammatory cytokine response, however, the innate pathogen-sensing mechanisms that transduce the signal for this response are poorly understood. In recent years, it has become increasingly evident that the Toll-like receptors (TLRs), which are germline-encoded pattern recognition receptors (PRRs), function as potent sensors for infection. TLRs can induce the activation of the innate immunity by recruiting specific intracellular adaptor proteins to initiate signaling pathways, which then culminating in activation of the nuclear factor kappa B (NF-κB) and interferon-regulatory factors (IRFs) that control the transcription of genes encoding type I interferon (IFN I) and other inflammatory cytokines. Furthermore, activation of innate immunity is critical for mounting adaptive immune responses. In parallel, common mechanisms used by viruses to counteract TLR-mediated responses or to actively subvert these pathways that block recognition and signaling through TLRs for their own benefit are emerging. Recent findings have demonstrated that TLR2 plays a crucial role in initiating the inflammatory process, and surprisingly that the response TLR2 triggers might be overzealous in its attempt to counter the attack by the virus. In this review, we summarize and discuss the recent advances about the specific role of TLR2 in triggering inflammatory responses in herpesvirus infection and the consequences of the alarms raised in the host that they are assigned to protect.
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Affiliation(s)
- Ming-sheng Cai
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
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31
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The costimulatory immunogen LPS induces the B-Cell clones that infiltrate transplanted human kidneys. Proc Natl Acad Sci U S A 2012; 109:6036-41. [PMID: 22492977 DOI: 10.1073/pnas.1202214109] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The mechanism of chronic rejection of transplanted human kidneys is unknown. An understanding of this process is important because, chronic rejection ultimately leads to loss of the kidney allograft in most transplants. One feature of chronic rejection is the infiltration of ectopic B-cell clusters that are clonal into the transplanted kidney. We now show that the antibodies produced by these B-cells react strongly with the core carbohydrate region of LPS. Since LPS is a costimulatory immunogen that can react with both the B-cell receptor (BCR) and the Toll-like receptor 4 (TLR4), these results suggest a mechanism for the selective pressure that leads to clonality of these B-cell clusters and opens the possibility that infection and the attendant exposure to LPS plays a role in the chronic rejection of human kidney transplants. If confirmed by clinical studies, these results suggest that treating patients with signs of chronic rejection with antibiotics may improve kidney allograft survival.
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Kakutani R, Adachi Y, Takata H, Kuriki T, Ohno N. Essential role of Toll-like receptor 2 in macrophage activation by glycogen. Glycobiology 2011; 22:146-59. [DOI: 10.1093/glycob/cwr122] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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van 't Veer C, van den Pangaart PS, Kruijswijk D, Florquin S, de Vos AF, van der Poll T. Delineation of the role of Toll-like receptor signaling during peritonitis by a gradually growing pathogenic Escherichia coli. J Biol Chem 2011; 286:36603-18. [PMID: 21690093 DOI: 10.1074/jbc.m110.189126] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
In a mouse model of Escherichia coli sepsis characterized by a primary peritoneal infection with 10(4) E. coli and a gradually growing bacterial load, we here show that the early cytokine response and antibacterial defense are dominated by TLR4 via a cooperative action of MyD88 and Trif. Although MyD88(-/-) mice succumbed earlier than WT mice in this E. coli peritonitis model, Trif(-/-) mice displayed a small but significant survival advantage. Despite a large early deficit in antimicrobial defense, TLR4(-/-) mice showed an unaltered survival with normal neutrophil attraction to the peritoneal cavity and normal or even elevated late cytokine release. TLR2 compensated for the lack of TLR4 because TLR2(-/-)/TLR4(-/-) mice did show decreased neutrophil attraction and increased mortality compared with WT mice. Nearly normal early peritoneal TNFα production and lack of early counterregulating systemic levels of the chemoattractant KC were associated with normal peritoneal neutrophil attraction in TLR4(-/-) mice. Late stage increased TNF, IL-1β, IFN-β, and typical IFN-γ production in TLR4(-/-) mice prompted us to evaluate expression of the negative feedback regulator SOCS-1. Lack of early hepatic SOCS-1 expression in TLR4(-/-) mice explained the late innate production of IFN-γ by the liver in TLR4(-/-) mice in this low dose E. coli peritonitis model. In contrast, early TLR4-induced IFN-γ production is described as a hallmark in high dose E. coli peritonitis models. The present study displays how the kinetics of pro- and anti-inflammatory mechanisms are regulated by TLRs during peritonitis by a gradually growing E. coli load and how these kinetics may affect outcome.
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Affiliation(s)
- Cornelis van 't Veer
- Center for Infection and Immunity Amsterdam, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands.
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Innate Immunity and Host Defense against Microbial Infection. Mol Microbiol 2011. [DOI: 10.1128/9781555816834.ch54] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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35
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Heine H. TLRs, NLRs and RLRs: innate sensors and their impact on allergic diseases--a current view. Immunol Lett 2011; 139:14-24. [PMID: 21554901 DOI: 10.1016/j.imlet.2011.04.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 04/19/2011] [Accepted: 04/20/2011] [Indexed: 12/25/2022]
Abstract
Charles Janeway first wrote 1989 about how important recognition of "certain characteristics or patterns common on infectious agents but absent from the host" would be for our immune response [1]. Surprisingly, it almost took 10 years before his ideas would lead to the revolutionary findings that fundamentally changed the view of the innate immune system over the past decade. Recognition of invading microorganisms belongs to the primary tasks of the innate immune system and is achieved through different families of innate immune sensors. Among these, Toll-like receptors (TLRs), nucleotide-binding domain and leucine-rich repeat containing receptors (NLRs) and Rig-I-like receptors (RLRs) have drawn major interests over the last decade. These receptor families are targeted by overlapping classes of pathogens and share functional domains and signal transduction pathways (see Fig. 1 and Table 1 for an overview of their structural organization, ligands, adaptors and activated pathways). This current view describes our present knowledge about these three main innate immune receptor families and their importance for adaptive immune responses such as asthma and allergy.
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Affiliation(s)
- Holger Heine
- Research Center Borstel - Leibniz-Center for Medicine and Biosciences, Division of Innate Immunity, Section of Immunoregulation, Parkallee 22, 23845 Borstel, Germany.
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Gorina R, Font-Nieves M, Márquez-Kisinousky L, Santalucia T, Planas AM. Astrocyte TLR4 activation induces a proinflammatory environment through the interplay between MyD88-dependent NFκB signaling, MAPK, and Jak1/Stat1 pathways. Glia 2010; 59:242-55. [DOI: 10.1002/glia.21094] [Citation(s) in RCA: 341] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Coffey TJ, Werling D. Therapeutic targeting of the innate immune system in domestic animals. Cell Tissue Res 2010; 343:251-61. [DOI: 10.1007/s00441-010-1054-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Accepted: 09/08/2010] [Indexed: 12/23/2022]
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Botero T, Son J, Vodopyanov D, Hasegawa M, Shelburne C, Nör J. MAPK Signaling Is Required for LPS-induced VEGF in Pulp Stem Cells. J Dent Res 2010; 89:264-9. [DOI: 10.1177/0022034509357556] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Caries-induced pulpitis is typically accompanied by an increase in dental pulp microvascular density. However, the mechanisms by which dental pulp cells recognize lipopolysaccharides (LPSs) remain unclear. We hypothesized that Porphyromonas endodontalis and Escherichia coli LPSs induce vascular endothelial growth factor (VEGF) expression in dental pulp stem cells (DPSC) and human dental pulp fibroblasts (HDPF) through mitogen-activated protein kinase (MAPK) signaling. ELISA, semi-quantitative RT-PCR, immunofluorescence, and Western blots were used. Here, we observed that LPSs induced VEGF expression in DPSC and HDPF cells, and both cell types express Toll-like receptor 4 (TLR- 4). Notably, LPS-induced VEGF is associated with phosphorylation of protein kinase C (PKC ζ) and extracellular signal-regulator kinase (ERK1/2) and is dependent upon MAPK activation. Analysis of these data, collectively, unveils a signaling pathway responsible for synthesis of VEGF by pulp cells and suggests a novel therapeutic target for the management of vascular responses in teeth with pulpitis.
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Affiliation(s)
- T.M. Botero
- Department of Cariology, Restorative Sciences, and Endodontics, University of Michigan School of Dentistry, 1011 N. University, Rm. 1376 D, Ann Arbor, Michigan 48109-1078, USA
- Department of Pathology, University of Michigan Medical School,
- Department of Biology and Materials Sciences, University of Michigan School of Dentistry,
- Department of Biomedical Engineering, University of Michigan College of Engineering,
- University of Michigan Comprehensive Cancer Center, Ann Arbor, Michigan 48109, USA
| | - J.S. Son
- Department of Cariology, Restorative Sciences, and Endodontics, University of Michigan School of Dentistry, 1011 N. University, Rm. 1376 D, Ann Arbor, Michigan 48109-1078, USA
- Department of Pathology, University of Michigan Medical School,
- Department of Biology and Materials Sciences, University of Michigan School of Dentistry,
- Department of Biomedical Engineering, University of Michigan College of Engineering,
- University of Michigan Comprehensive Cancer Center, Ann Arbor, Michigan 48109, USA
| | - D. Vodopyanov
- Department of Cariology, Restorative Sciences, and Endodontics, University of Michigan School of Dentistry, 1011 N. University, Rm. 1376 D, Ann Arbor, Michigan 48109-1078, USA
- Department of Pathology, University of Michigan Medical School,
- Department of Biology and Materials Sciences, University of Michigan School of Dentistry,
- Department of Biomedical Engineering, University of Michigan College of Engineering,
- University of Michigan Comprehensive Cancer Center, Ann Arbor, Michigan 48109, USA
| | - M. Hasegawa
- Department of Cariology, Restorative Sciences, and Endodontics, University of Michigan School of Dentistry, 1011 N. University, Rm. 1376 D, Ann Arbor, Michigan 48109-1078, USA
- Department of Pathology, University of Michigan Medical School,
- Department of Biology and Materials Sciences, University of Michigan School of Dentistry,
- Department of Biomedical Engineering, University of Michigan College of Engineering,
- University of Michigan Comprehensive Cancer Center, Ann Arbor, Michigan 48109, USA
| | - C.E. Shelburne
- Department of Cariology, Restorative Sciences, and Endodontics, University of Michigan School of Dentistry, 1011 N. University, Rm. 1376 D, Ann Arbor, Michigan 48109-1078, USA
- Department of Pathology, University of Michigan Medical School,
- Department of Biology and Materials Sciences, University of Michigan School of Dentistry,
- Department of Biomedical Engineering, University of Michigan College of Engineering,
- University of Michigan Comprehensive Cancer Center, Ann Arbor, Michigan 48109, USA
| | - J.E. Nör
- Department of Cariology, Restorative Sciences, and Endodontics, University of Michigan School of Dentistry, 1011 N. University, Rm. 1376 D, Ann Arbor, Michigan 48109-1078, USA
- Department of Pathology, University of Michigan Medical School,
- Department of Biology and Materials Sciences, University of Michigan School of Dentistry,
- Department of Biomedical Engineering, University of Michigan College of Engineering,
- University of Michigan Comprehensive Cancer Center, Ann Arbor, Michigan 48109, USA
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Structural and biological diversity of lipopolysaccharides from Burkholderia pseudomallei and Burkholderia thailandensis. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2009; 16:1420-8. [PMID: 19692625 DOI: 10.1128/cvi.00472-08] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Burkholderia pseudomallei, the etiological agent of melioidosis, is a facultative intracellular pathogen. As B. pseudomallei is a gram-negative bacterium, its outer membrane contains lipopolysaccharide (LPS) molecules, which have been shown to have low-level immunological activities in vitro. In this study, the biological activities of B. pseudomallei LPS were compared to those of Burkholderia thailandensis LPS, and it was found that both murine and human macrophages produced levels of tumor necrosis factor alpha, interleukin-6 (IL-6), and IL-10 in response to B. pseudomallei LPS that were lower than those in response to B. thailandensis LPS in vitro. In order to elucidate the molecular mechanisms underlying the low-level immunological activities of B. pseudomallei LPS, its lipid A moiety was characterized using mass spectrometry. The major lipid A species identified in B. pseudomallei consists of a biphosphorylated disaccharide backbone, which is modified with 4-amino-4-deoxy-arabinose (Ara4N) at both phosphates and penta-acylated with fatty acids (FA) C(14:0)(3-OH), C(16:0)(3-OH), and either C(14:0) or C(14:0)(2-OH). In contrast, the major lipid A species identified in B. thailandensis was a mixture of tetra- and penta-acylated structures with differing amounts of Ara4N and FA C(14:0)(3-OH). Lipid A species acylated with FA C(14:0)(2-OH) were unique to B. pseudomallei and not found in B. thailandensis. Our data thus indicate that B. pseudomallei synthesizes lipid A species with long-chain FA C(14:0)(2-OH) and Ara4N-modified phosphate groups, allowing it to evade innate immune recognition.
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Alhawi M, Stewart J, Erridge C, Patrick S, Poxton IR. Bacteroides fragilis signals through Toll-like receptor (TLR) 2 and not through TLR4. J Med Microbiol 2009; 58:1015-1022. [PMID: 19528164 DOI: 10.1099/jmm.0.009936-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Although it is desirable to identify the interactions between endotoxin/LPS and the innate immune mechanism, it is often not possible to isolate these interactions from other cell wall-related structures of protein or polysaccharide origin. There is no universally accepted method to extract different LPSs from different bacteria, and their natural state will be influenced by their interactions with the associated molecules in the bacterial outer membrane. It is now believed that Toll-like receptor (TLR) 4 is the main signal transducer of classical LPS (i.e. Escherichia coli LPS), while TLR2 is used by certain non-classical LPSs. There are contradictory reports as to whether Bacteroides fragilis LPS, a non-classical LPS, signals primarily through TLR2 or TLR4. This study was designed to address this problem. Different non-purified and purified B. fragilis LPSs extracted by different methods together with different heat-killed, whole-cell populations of B. fragilis were used to elucidate the TLR specificity. All of these B. fragilis preparations showed a significant signalling specificity for TLR2 but not for TLR4. This indicates that changing the extraction methods, with or without applying a repurification procedure, and varying the cell populations do not alter the TLR specificity of B. fragilis LPS.
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Affiliation(s)
- Mohammad Alhawi
- Medical Microbiology, Centre for Infectious Diseases, University of Edinburgh College of Medicine and Veterinary Medicine, Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK
| | - John Stewart
- Medical Microbiology, Centre for Infectious Diseases, University of Edinburgh College of Medicine and Veterinary Medicine, Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK
| | - Clett Erridge
- Department of Cardiovascular Sciences, University of Leicester, Clinical Science Wing, Glenfield General Hospital, Leicester LE3 9QP, UK
| | - Sheila Patrick
- Centre for Infection and Immunity, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Ian R Poxton
- Medical Microbiology, Centre for Infectious Diseases, University of Edinburgh College of Medicine and Veterinary Medicine, Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK
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O'Neill LAJ, Bryant CE, Doyle SL. Therapeutic targeting of Toll-like receptors for infectious and inflammatory diseases and cancer. Pharmacol Rev 2009; 61:177-97. [PMID: 19474110 DOI: 10.1124/pr.109.001073] [Citation(s) in RCA: 333] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Since first being described in the fruit fly Drosophila melanogaster, Toll-like receptors (TLRs) have proven to be of great interest to immunologists and investigators interested in the molecular basis to inflammation. They recognize pathogen-derived factors and also products of inflamed tissue, and trigger signaling pathways that lead to activation of transcription factors such as nuclear factor-kappaB and the interferon regulatory factors. These in turn lead to induction of immune and inflammatory genes, including such important cytokines as tumor necrosis factor-alpha and type I interferon. Much evidence points to a role for TLRs in immune and inflammatory diseases and increasingly in cancer. Examples include clear roles for TLR4 in sepsis, rheumatoid arthritis, ischemia/reperfusion injury, and allergy. TLR2 has been implicated in similar pathologic conditions and also in systemic lupus erythematosus (SLE) and tumor metastasis. TLR7 has also been shown to be important in SLE. TLR5 has been shown to be radioprotective. Recent advances in our understanding of signaling pathways activated by TLRs, structural insights into TLRs bound to their ligands and antagonists, and approaches to inhibit TLRs (including antibodies, peptides, and small molecules) are providing possiblemeans by which to interfere with TLRs clinically. Here we review these recent advances and speculate about whether manipulating TLRs is likely to be successful in fighting off different diseases.
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Affiliation(s)
- Luke A J O'Neill
- School of Biochemistry and Immunology, Trinity College Dublin, Ireland.
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Lotter H, González-Roldán N, Lindner B, Winau F, Isibasi A, Moreno-Lafont M, Ulmer AJ, Holst O, Tannich E, Jacobs T. Natural killer T cells activated by a lipopeptidophosphoglycan from Entamoeba histolytica are critically important to control amebic liver abscess. PLoS Pathog 2009; 5:e1000434. [PMID: 19436711 PMCID: PMC2674934 DOI: 10.1371/journal.ppat.1000434] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Accepted: 04/16/2009] [Indexed: 02/06/2023] Open
Abstract
The innate immune response is supposed to play an essential role in the control of amebic liver abscess (ALA), a severe form of invasive amoebiasis due to infection with the protozoan parasite Entamoeba histolytica. In a mouse model for the disease, we previously demonstrated that Jalpha18(-/-) mice, lacking invariant natural killer T (iNKT) cells, suffer from more severe abscess development. Here we show that the specific activation of iNKT cells using alpha-galactosylceramide (alpha-GalCer) induces a significant reduction in the sizes of ALA lesions, whereas CD1d(-/-) mice develop more severe abscesses. We identified a lipopeptidophosphoglycan from E. histolytica membranes (EhLPPG) as a possible natural NKT cell ligand and show that the purified phosphoinositol (PI) moiety of this molecule induces protective IFN-gamma but not IL-4 production in NKT cells. The main component of EhLPPG responsible for NKT cell activation is a diacylated PI, (1-O-[(28:0)-lyso-glycero-3-phosphatidyl-]2-O-(C16:0)-Ins). IFN-gamma production by NKT cells requires the presence of CD1d and simultaneously TLR receptor signalling through MyD88 and secretion of IL-12. Similar to alpha-GalCer application, EhLPPG treatment significantly reduces the severity of ALA in ameba-infected mice. Our results suggest that EhLPPG is an amebic molecule that is important for the limitation of ALA development and may explain why the majority of E. histolytica-infected individuals do not develop amebic liver abscess.
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Affiliation(s)
- Hannelore Lotter
- Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany
- * E-mail: (HL); (OH)
| | - Nestor González-Roldán
- Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany
- Division of Structural Biochemistry, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Borstel, Germany
- Unidad de Investigación Médica en Inmunoquímica, Hospital de Especialidades del Centro Médico Nacional Siglo XXI del Instituto Mexicano del Seguro Social (IMSS), Mexico City, Mexico
- Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Buko Lindner
- Division of Immunochemistry, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Borstel, Germany
| | - Florian Winau
- Immune Disease Institute and Department of Pathology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Armando Isibasi
- Unidad de Investigación Médica en Inmunoquímica, Hospital de Especialidades del Centro Médico Nacional Siglo XXI del Instituto Mexicano del Seguro Social (IMSS), Mexico City, Mexico
| | - Martha Moreno-Lafont
- Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Artur J. Ulmer
- Division of Immunology and Cell Biology, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Borstel, Germany
| | - Otto Holst
- Division of Structural Biochemistry, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Borstel, Germany
- * E-mail: (HL); (OH)
| | - Egbert Tannich
- Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany
| | - Thomas Jacobs
- Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany
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Slevogt H, Zabel S, Opitz B, Hocke A, Eitel J, N'Guessan PD, Lucka L, Riesbeck K, Zimmermann W, Zweigner J, Temmesfeld-Wollbrueck B, Suttorp N, Singer BB. CEACAM1 inhibits Toll-like receptor 2–triggered antibacterial responses of human pulmonary epithelial cells. Nat Immunol 2008; 9:1270-8. [DOI: 10.1038/ni.1661] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Accepted: 09/02/2008] [Indexed: 01/11/2023]
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West TE, Ernst RK, Jansson-Hutson MJ, Skerrett SJ. Activation of Toll-like receptors by Burkholderia pseudomallei. BMC Immunol 2008; 9:46. [PMID: 18691413 PMCID: PMC2527550 DOI: 10.1186/1471-2172-9-46] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2008] [Accepted: 08/08/2008] [Indexed: 12/13/2022] Open
Abstract
Background Melioidosis, a lethal tropical infection that is endemic in southeast Asia and northern Australia, is caused by the saprophytic Gram-negative bacterium Burkholderia pseudomallei. Overall mortality approaches 40% yet little is known about mechanisms of host defense. Toll-like receptors (TLRs) are host transmembrane receptors that recognize conserved pathogen molecular patterns and induce an inflammatory response. The lipopolysaccharide (LPS) of Gram-negative bacteria is a potent inducer of the host innate immune system. TLR4, in association with MD-2, is the archetype receptor for LPS although B. pseudomallei LPS has been previously identified as a TLR2 agonist. We examined TLR signaling induced by B. pseudomallei, B. pseudomallei LPS, and B. pseudomallei lipid A using gain-of-function transfection assays of NF-κB activation and studies of TLR-deficient macrophages. Results In HEK293 cells transfected with murine or human TLRs, CD14, and MD-2, heat-killed B. pseudomallei activated TLR2 (in combination with TLR1 or TLR6) and TLR4. B. pseudomallei LPS and lipid A activated TLR4 and this TLR4-mediated signaling required MD-2. In TLR2-/- macrophages, stimulation with heat-killed B. pseudomallei augmented TNF-α and MIP-2 production whereas in TLR4-/- cells, TNF-α, MIP-2, and IL-10 production was reduced. Cytokine production by macrophages stimulated with B. pseudomallei LPS or lipid A was entirely dependent on TLR4 but was increased in the absence of TLR2. TLR adaptor molecule MyD88 strongly regulated TNF-α production in response to heat-killed B. pseudomallei. Conclusion B. pseudomallei activates TLR2 and TLR4. In the presence of MD-2, B. pseudomallei LPS and lipid A are TLR4 ligands. Although the macrophage cytokine response to B. pseudomallei LPS or lipid A is completely dependent on TLR4, in TLR2-/- macrophages stimulated with B. pseudomallei, B. pseudomallei LPS or lipid A, cytokine production is augmented. Other MyD88-dependent signaling pathways may also be important in the host response to B. pseudomallei infection. These findings provide new insights into critical mechanisms of host defense in melioidosis.
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Affiliation(s)
- T Eoin West
- Department of Medicine, University of Washington, Seattle, Washington, USA.
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Ikeda Y, Adachi Y, Ishii T, Miura N, Tamura H, Ohno N. Dissociation of Toll-like receptor 2-mediated innate immune response to Zymosan by organic solvent-treatment without loss of Dectin-1 reactivity. Biol Pharm Bull 2008; 31:13-8. [PMID: 18175935 DOI: 10.1248/bpb.31.13] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Zymosan activates phagocytes through the innate immune system and causes inflammatory responses in animals. Because of the complexity of the active substances included in Zymosan preparations, simplifying the active moiety actually responsible for innate immune recognition is needed. One way to remove possible active substances from commercially available Zymosan preparations is to wash then with pyrogen-free water to obtain a ZWIS (Zymosan water insoluble fraction), ethanol insoluble (EtIS), or chloroform/methanol insoluble (CMIS) preparation. The effects of various washed Zymosan preparations on nuclear factor (NF)-kappaB activation and binding to beta-glucan recognition protein were examined. Significant NF-kappaB activation by Toll-like receptor (TLR) 2-expressing HEK293 cells and enhanced NF-kappaB activity via the co-expression of TLR2 and Dectin-1, a functional beta-glucan receptor, was only observed in response to ZWIS. However, the ability of Zymosan preparations to bind Dectin-1 protein was not altered even after treatment with the organic solvents by which the TLR2-mediated NF-kappaB activity was abolished. Another NF-kappaB activation pathway involving CARD9/Bcl10 was triggered by these Zymosan preparations in the presence of Dectin-1. The results suggest that the beta-glucan-dependent characteristics of Zymosan were not affected by the washing with chloroform/methanol or ethanol, and that TLR2-mediated activity was easily eliminated with these organic solvents. This treatment might be useful for distinguishing natural ligands for TLR2 and beta-glucan receptors when studying the innate immune response to fungal macromolecules.
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Affiliation(s)
- Yoshihiko Ikeda
- Laboratory for Immunopharmacology of Microbial Products, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
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Koch A, Boehm O, Zacharowski PA, Loer SA, Weimann J, Rensing H, Foster SJ, Schmidt R, Berkels R, Reingruber S, Zacharowski K. Inducible nitric oxide synthase and heme oxygenase-1 in the lung during lipopolysaccharide tolerance and cross tolerance. Crit Care Med 2007; 35:2775-84. [PMID: 17901834 DOI: 10.1097/01.ccm.0000288122.24212.40] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
OBJECTIVE Pretreatment with low-dose lipopolysaccharide protects cells/organs against a subsequent lethal Gram-negative (lipopolysaccharide tolerance) or Gram-positive (cross tolerance) stimulus. We determined whether this occurs in the rat lung. The involvement of inducible nitric oxide synthase and heme oxygenase-1 was evaluated. DESIGN Laboratory study. SETTING University hospital laboratory. SUBJECTS Anesthetized male Wistar rats. INTERVENTIONS To test the hypothesis, rats received saline or lipopolysaccharide (1 mg/kg). At 2, 4, 8, 16, or 24 hrs later, blood samples and lung tissue were taken to determine messenger RNA, protein concentration, and activity of inducible nitric oxide synthase and heme oxygenase-1. In additional experiments, rats were challenged with lipopolysaccharide (1 mg/kg) and subjected to Gram-negative (lipopolysaccharide) or Gram-positive (lipoteichoic acid and peptidoglycan) shock 24 hrs later. These studies were carried out in the presence and absence of inducible nitric oxide synthase or heme oxygenase-1 inhibitors (1400W or tin protoporphyrin IX). Following 6 hrs of shock, lung tissue was taken to determine lung damage and heme oxygenase-1 concentration and activity. MEASUREMENTS AND MAIN RESULTS In the rat lung, lipopolysaccharide (1 mg/kg) induced a significant increase in inducible nitric oxide synthase protein at 8 hrs with a corresponding increase in plasma nitrate/nitrite at 8-16 hrs. Simultaneously, heme oxygenase-1 messenger RNA transcripts were observed at 8-16 hrs, and maximal expression of the protein followed (24 hrs). Pretreatment with low-dose lipopolysaccharide reduced myeloperoxidase activity (neutrophil infiltration) and wet-dry ratio (pulmonary edema) in the lungs of animals subjected to Gram-negative or Gram-positive shock, demonstrating tolerance. Pretreatment with low-dose lipopolysaccharide and the selective inducible nitric oxide synthase inhibitor 1400W reduced heme oxygenase-1 protein expression, and lung protection was abolished. Tin protoporphyrin IX did not affect heme oxygenase-1 expression, but heme oxygenase activity and lung protection were significantly reduced. CONCLUSIONS We propose that nitric oxide (most likely inducible nitric oxide synthase derived) regulates the induction of heme oxygenase-1 in the lung, which in turn plays an important part in pulmonary protection during lipopolysaccharide tolerance and cross tolerance.
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Affiliation(s)
- Alexander Koch
- Molecular Cardioprotection and Inflammation Group, Department of Anesthesia, Bristol University, Bristol, UK
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Thakran S, Li H, Lavine CL, Miller MA, Bina JE, Bina XR, Re F. Identification of Francisella tularensis lipoproteins that stimulate the toll-like receptor (TLR) 2/TLR1 heterodimer. J Biol Chem 2007; 283:3751-60. [PMID: 18079113 DOI: 10.1074/jbc.m706854200] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The innate immune response to Francisella tularensis is primarily mediated by TLR2, though the bacterial products that stimulate this receptor remain unknown. Here we report the identification of two Francisella lipoproteins, TUL4 and FTT1103, which activate TLR2. We demonstrate that TUL4 and FTT1103 stimulate chemokine production in human and mouse cells in a TLR2-dependent way. Using an assay that relies on chimeric TLR proteins, we show that TUL4 and FTT1103 stimulate exclusively the TLR2/TLR1 heterodimer. Our results also show that yet unidentified Francisella proteins, possibly unlipi-dated, have the ability to stimulate the TLR2/TLR6 heterodimer. Through domain-exchange analysis, we determined that an extended region that comprises LRR 9-17 in the extra-cellular portion of TLR1 mediates response to Francisella lipoproteins and triacylated lipopeptide. Substitution of the corresponding LRR of TLR6 with the LRR derived from TLR1 enables TLR6 to recognize TUL4, FTT1103, and triacylated lipopeptide. This study identifies for the first time specific Fran-cisella products capable of stimulating a proinflammatory response and the cellular receptors they trigger.
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Affiliation(s)
- Shalini Thakran
- Department of Molecular Sciences, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
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Inducible nitric oxide synthase and heme oxygenase-1 in the lung during lipopolysaccharide tolerance and cross tolerance. Crit Care Med 2007. [DOI: 10.1097/00003246-200712000-00016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Spiller S, Dreher S, Meng G, Grabiec A, Thomas W, Hartung T, Pfeffer K, Hochrein H, Brade H, Bessler W, Wagner H, Kirschning CJ. Cellular recognition of trimyristoylated peptide or enterobacterial lipopolysaccharide via both TLR2 and TLR4. J Biol Chem 2007; 282:13190-8. [PMID: 17353199 DOI: 10.1074/jbc.m610340200] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Evidence for specific and direct bacterial product recognition through toll-like receptors (TLRs) has been emphasized recently. We analyzed lipopeptide analogues and enterobacterial lipopolysaccharide (eLPS) for their potential to activate cells through TLR2 and TLR4. Whereas bacterial protein palmitoylated at its N-terminal cysteine and N-terminal peptides derived thereof are known to induce TLR2-mediated cell activation, a synthetic acylhexapeptide mimicking a bacterial lipoprotein subpopulation for which N-terminal trimyristoylation is characteristic (Myr(3)CSK(4)) activated cells not only through TLR2 but also through TLR4. Conversely, highly purified eLPS triggered cell activation through overexpressed TLR2 in the absence of TLR4 expression if CD14 was coexpressed. Accordingly, TLR2(-/-) macrophages prepared upon gene targeting responded to Myr(3)CSK(4) challenge, whereas TLR2(-/-)/TLR4(d/d) cells were unresponsive. Through interferon-gamma (IFNgamma) priming, macrophages lacking expression of functional TLR4 and/or MD-2 acquired sensitivity to eLPS, whereas TLR2/TLR4 double deficient cells did not. Not only TLR2(-/-) mice but also TLR4(-/-) mice were resistant to Myr(3)CSK(4) challenge-induced fatal shock. d-Galactosamine-sensitized mice expressing defective TLR4 or lacking TLR4 expression acquired susceptibility to eLPS-driven toxemia upon IFNgamma priming, whereas double deficient mice did not. Immunization toward ovalbumin using Myr(3)CSK(4) as adjuvant was ineffective in TLR2(-/-)/TLR4(-/-) mice yet effective in wild-type, TLR2(-/-), or TLR4(-/-) mice as shown by analysis of ovalbumin-specific serum Ig concentration. A compound such as Myr(3)CSK(4) whose stimulatory activity is mediated by both TLR2 and TLR4 might constitute a preferable adjuvant. On the other hand, simultaneous blockage of both of the two TLRs might effectively inhibit infection-induced pathology.
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Affiliation(s)
- Stephan Spiller
- Institute of Medical Microbiology, Immunology, and Hygiene, Technical University of Munich, 81675 Munich, Germany
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Hashimoto M, Furuyashiki M, Kaseya R, Fukada Y, Akimaru M, Aoyama K, Okuno T, Tamura T, Kirikae T, Kirikae F, Eiraku N, Morioka H, Fujimoto Y, Fukase K, Takashige K, Moriya Y, Kusumoto S, Suda Y. Evidence of immunostimulating lipoprotein existing in the natural lipoteichoic acid fraction. Infect Immun 2007; 75:1926-32. [PMID: 17283098 PMCID: PMC1865665 DOI: 10.1128/iai.02083-05] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Lipoteichoic acid (LTA) is a cell surface glycoconjugate of gram-positive bacteria and is reported to activate the innate immune system. We previously reported that purified LTA obtained from Enterococcus hirae has no immunostimulating activity, but a subfraction (Eh-AF) in an LTA fraction possesses activity. In this study, we established a mouse monoclonal antibody neutralizing the activity of Eh-AF and investigated its inhibitory effects. Monoclonal antibody (MAbEh1) was established by the immunization of BALB/c mice with Eh-AF, followed by hybridoma screening based on its inhibitory effect for the production of interleukin-6 (IL-6) induced by Eh-AF. MAbEh1 neutralized the production of IL-6 by LTA fraction from not only E. hirae but also Staphylococcus aureus, while it failed to block that of lipopolysaccharide, suggesting that the antibody recognized a common active structure(s) in LTA fractions. Synthetic glycolipids in these LTAs did not induce cytokine production, at least in our system. Interestingly, the antibody was found to inhibit the activity of immunostimulating synthetic lipopeptides, Pam(3)CSK(4) and FSL-1. These results suggest that MAbEh1 neutralizes the activity of lipoprotein-like compounds which is responsible for the activity of the LTA fraction of E. hirae and S. aureus.
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Affiliation(s)
- Masahito Hashimoto
- Department of Nanostructure and Advanced Materials, Kagoshima University, Korimoto 1-21-40, Kagoshima 890-0065, Japan
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