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Wang H, Liu D, Zhou X. Effect of Mycolic Acids on Host Immunity and Lipid Metabolism. Int J Mol Sci 2023; 25:396. [PMID: 38203570 PMCID: PMC10778799 DOI: 10.3390/ijms25010396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 09/19/2023] [Accepted: 09/21/2023] [Indexed: 01/12/2024] Open
Abstract
Mycolic acids constitute pivotal constituents within the cell wall structure of Mycobacterium tuberculosis. Due to their structural diversity, the composition of mycolic acids exhibits substantial variations among different strains, endowing them with the distinctive label of being the 'signature' feature of mycobacterial species. Within Mycobacterium tuberculosis, the primary classes of mycolic acids include α-, keto-, and methoxy-mycolic acids. While these mycolic acids are predominantly esterified to the cell wall components (such as arabinogalactan, alginate, or glucose) of Mycobacterium tuberculosis, a fraction of free mycolic acids are secreted during in vitro growth of the bacterium. Remarkably, different types of mycolic acids possess varying capabilities to induce foamy macro-phages and trigger immune responses. Additionally, mycolic acids play a regulatory role in the lipid metabolism of host cells, thereby exerting influence over the progression of tuberculosis. Consequently, the multifaceted properties of mycolic acids shape the immune evasion strategy employed by Mycobacterium tuberculosis. A comprehensive understanding of mycolic acids is of paramount significance in the pursuit of developing tuberculosis therapeutics and unraveling the intricacies of its pathogenic mechanisms.
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Affiliation(s)
- Haoran Wang
- College of Veterinary Medicine, China Agricultural University, Beijing 100086, China; (H.W.); (D.L.)
- National Key Laboratory of Veterinary Public Health and Safety, Beijing 100086, China
| | - Dingpu Liu
- College of Veterinary Medicine, China Agricultural University, Beijing 100086, China; (H.W.); (D.L.)
- National Key Laboratory of Veterinary Public Health and Safety, Beijing 100086, China
| | - Xiangmei Zhou
- College of Veterinary Medicine, China Agricultural University, Beijing 100086, China; (H.W.); (D.L.)
- National Key Laboratory of Veterinary Public Health and Safety, Beijing 100086, China
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RNA Microarray-Based Comparison of Innate Immune Phenotypes between Human THP-1 Macrophages Stimulated with Two BCG Strains. Int J Mol Sci 2022; 23:ijms23094525. [PMID: 35562916 PMCID: PMC9103163 DOI: 10.3390/ijms23094525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 04/13/2022] [Indexed: 12/10/2022] Open
Abstract
Currently, the only available vaccine against tuberculosis is Mycobacterium bovis Bacille Calmette-Guérin (BCG). Pulmonary tuberculosis protection provided by the vaccine varies depending on the strain, the patient’s age and the evaluated population. Although the adaptive immune responses induced by different BCG strains have been widely studied, little conclusive data is available regarding innate immune responses, especially in macrophages. Here, we aimed to characterize the innate immune responses of human THP-1-derived macrophages at the transcriptional level following a challenge with either the BCG Mexico (M.BCG) or Phipps (P.BCG) strains. After a brief in vitro characterization of the bacterial strains and the innate immune responses, including nitric oxide production and cytokine profiles, we analyzed the mRNA expression patterns and performed pathway enrichment analysis using RNA microarrays. Our results showed that multiple biological processes were enriched, especially those associated with innate inflammatory and antimicrobial responses, including tumor necrosis factor (TNF)-α, type I interferon (IFN-I) and IFN-γ. However, four DEGs were identified in macrophages infected with M.BCG compared to P. BCG. These findings indicated the proinflammatory stimulation of macrophages induced by both BCG strains, at the cytokine level and in terms of gene expression, suggesting a differential expression pattern of innate immune transcripts depending on the mycobacterial strain.
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Synthesis of a Di-Mycoloyl Tri-Arabinofuranosyl Glycerol Fragment of the Mycobacterial Cell Wall, Based on Synthetic Mycolic Acids. Molecules 2019; 24:molecules24193596. [PMID: 31590468 PMCID: PMC6804083 DOI: 10.3390/molecules24193596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 09/24/2019] [Accepted: 10/01/2019] [Indexed: 11/24/2022] Open
Abstract
Fragments of mycobacterial cell walls such as arabinoglycerol mycolate and dimycoloyl diarabinoglycerol, comprising complex mixtures of mycolic acids, have immunostimulatory and antigenic properties. A related di-mycoloyl tri-arabinofuranosyl glycerol fragment has been isolated from cell wall hydrolysates. An effective stereoselective synthesis of tri-arabinofuranosyl glycerol, followed by coupling with stereochemically defined mycolic acids of different structural classes, to provide unique di-mycoloyl tri-arabinofuranosyl glycerols is now described.
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Ali OT, Mohammed MO, Gates PJ, Baird MS, Al Dulayymi JR. The synthesis of mycobacterial dimycoloyl diarabinoglycerol based on defined synthetic mycolic acids. Chem Phys Lipids 2019; 221:207-218. [PMID: 30639038 DOI: 10.1016/j.chemphyslip.2019.01.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 12/21/2018] [Accepted: 01/08/2019] [Indexed: 11/25/2022]
Abstract
Complex mixtures of natural dimycoloyl diarabinoglycerols isolated from mycobacteria have been shown to be both potent immune signalling agents and potentially valuable antigens in the serodiagnosis of mycobacterial infections. We now report the highly stereocontrolled synthesis of diacyl l-glycerol-(1'→1)-β-d-arabinofuranosyl-α-d-arabinofuranosides based on simple fatty acids and single defined synthetic mycolic acids. NMR analysis confirmed that the synthetic core was identical to that in natural mixtures.
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Affiliation(s)
- Omar T Ali
- School of Chemistry, Bangor University, Bangor, Gwynedd, LL57 2UW, UK
| | - Mohsin O Mohammed
- School of Chemistry, Bangor University, Bangor, Gwynedd, LL57 2UW, UK
| | - Paul J Gates
- School of Chemistry, Bristol University, Bristol, BS8 1TS, UK
| | - Mark S Baird
- School of Chemistry, Bangor University, Bangor, Gwynedd, LL57 2UW, UK.
| | - Juma'a R Al Dulayymi
- School of Chemistry, Bangor University, Bangor, Gwynedd, LL57 2UW, UK; School of Natural Sciences, Bangor University, Bangor, Gwynedd, LL57 2UW, UK
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Braganza CD, Teunissen T, Timmer MSM, Stocker BL. Identification and Biological Activity of Synthetic Macrophage Inducible C-Type Lectin Ligands. Front Immunol 2018; 8:1940. [PMID: 29387054 PMCID: PMC5776103 DOI: 10.3389/fimmu.2017.01940] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Accepted: 12/15/2017] [Indexed: 11/15/2022] Open
Abstract
The macrophage inducible C-type lectin (Mincle) is a pattern recognition receptor able to recognize both damage-associated and pathogen-associated molecular patterns, and in this respect, there has been much interest in determining the scope of ligands that bind Mincle and how structural modifications to these ligands influence ensuing immune responses. In this review, we will present Mincle ligands of known chemical structure, with a focus on ligands that have been synthetically prepared, such as trehalose glycolipids, glycerol-based ligands, and 6-acylated glucose and mannose derivatives. The ability of the different classes of ligands to influence the innate, and consequently, the adaptive, immune response will be described, and where appropriate, structure-activity relationships within each class of Mincle ligands will be presented.
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Affiliation(s)
- Chriselle D. Braganza
- School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
- Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
| | - Thomas Teunissen
- School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
- Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
| | - Mattie S. M. Timmer
- School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
- Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
| | - Bridget L. Stocker
- School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
- Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
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Mohammed MO, Al Dulayymi JR, Baird MS. Preparation of the tri-arabino di-mycolate fragment of mycobacterial arabinogalactan from defined synthetic mycolic acids. Carbohydr Res 2017; 437:36-42. [DOI: 10.1016/j.carres.2016.11.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 11/07/2016] [Accepted: 11/07/2016] [Indexed: 11/30/2022]
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Tima HG, Al Dulayymi JR, Denis O, Lehebel P, Baols KS, Mohammed MO, L'Homme L, Sahb MM, Potemberg G, Legrand S, Lang R, Beyaert R, Piette J, Baird MS, Huygen K, Romano M. Inflammatory Properties and Adjuvant Potential of Synthetic Glycolipids Homologous to Mycolate Esters of the Cell Wall of Mycobacterium tuberculosis. J Innate Immun 2016; 9:162-180. [PMID: 27855374 DOI: 10.1159/000450955] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 09/21/2016] [Indexed: 12/30/2022] Open
Abstract
The cell wall of mycobacteria is characterised by glycolipids composed of different classes of mycolic acids (MAs; alpha-, keto-, and methoxy-) and sugars (trehalose, glucose, and arabinose). Studies using mutant Mtb strains have shown that the structure of MAs influences the inflammatory potential of these glycolipids. As mutant Mtb strains possess a complex mixture of glycolipids, we analysed the inflammatory potential of single classes of mycolate esters of the Mtb cell wall using 38 different synthetic analogues. Our results show that synthetic trehalose dimycolate (TDM) and trehalose, glucose, and arabinose monomycolates (TMM, GMM, and AraMM) activate bone marrow-derived dendritic cells in terms of the production of pro-inflammatory cytokines (IL-6 and TNF-α) and reactive oxygen species, upregulation of costimulatory molecules, and activation of NLRP3 inflammasome by a mechanism dependent on Mincle. These findings demonstrate that Mincle receptor can also recognise pentose esters and seem to contradict the hypothesis that production of GMM is an escape mechanism used by pathogenic mycobacteria to avoid recognition by the innate immune system. Finally, our experiments indicate that TMM and GMM, as well as TDM, can promote Th1 and Th17 responses in mice in an OVA immunisation model, and that further analysis of their potential as novel adjuvants for subunit vaccines is warranted.
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Affiliation(s)
- Hermann Giresse Tima
- Scientific Service Immunology, O.D. Communicable and Infectious Diseases, Scientific Institute of Public Health (WIV-ISP), Brussels, Belgium
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Mohammed MO, Baird MS, Al Dulayymi JR, Jones A, Gwenin CD. Arabino mycolates from synthetic mycolic acids. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.03.083] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Tima HG, Huygen K, Romano M. Innate signaling by mycobacterial cell wall components and relevance for development of adjuvants for subunit vaccines. Expert Rev Vaccines 2016; 15:1409-1420. [PMID: 27206681 DOI: 10.1080/14760584.2016.1187067] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Pathogen recognition receptors (PRRs) recognize pathogen-associated molecular patterns, triggering the induction of inflammatory innate responses and contributing to the development of specific adaptive immune responses. Novel adjuvants have been developed based on agonists of PRRs. Areas covered: Lipid pathogen-associated molecular patterns (PAMPs) present in the cell wall of mycobacteria are revised, with emphasis on agonists of C-type lectin receptors, signaling pathways, and preclinical data supporting their use as novel adjuvants inducing cell-mediated immune responses. Their potential use as lipid antigens in novel tuberculosis subunit vaccines is also discussed. Expert commentary: Few adjuvants are licensed for human use and mainly favour antibody-mediated protective immunity. Use of lipid PAMPs that trigger cell-mediated immune responses could lead to the development of adjuvants for vaccines against intracellular pathogens and cancer.
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Affiliation(s)
- Hermann Giresse Tima
- a Immunology Service, Communicable and Infectious Diseases Department , Scientific Institute of Public Health (WIV-ISP) , Brussels , Belgium
| | - Kris Huygen
- a Immunology Service, Communicable and Infectious Diseases Department , Scientific Institute of Public Health (WIV-ISP) , Brussels , Belgium
| | - Marta Romano
- a Immunology Service, Communicable and Infectious Diseases Department , Scientific Institute of Public Health (WIV-ISP) , Brussels , Belgium
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Dowling JK, Mansell A. Toll-like receptors: the swiss army knife of immunity and vaccine development. Clin Transl Immunology 2016; 5:e85. [PMID: 27350884 PMCID: PMC4910119 DOI: 10.1038/cti.2016.22] [Citation(s) in RCA: 178] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 03/31/2016] [Accepted: 04/05/2016] [Indexed: 12/27/2022] Open
Abstract
Innate immune cells have a critical role in defense against infection and disease. Central to this is the broad specificity with which they can detect pathogen-associated patterns and danger-associated patterns via the pattern recognition receptors (PRRs) they express. Several families of PRRs have been identified including: Toll-like receptors (TLRs), C-type lectin-like receptors, retinoic acid-inducible gene-like receptors and nucleotide-binding oligomerization domain-like receptors. TLRs are one of the most largely studied families of PRRs. The binding of ligands to TLRs on antigen presenting cells (APCs), mainly dendritic cells, leads to APC maturation, induction of inflammatory cytokines and the priming of naive T cells to drive acquired immunity. Therefore, activation of TLRs promotes both innate inflammatory responses and the induction of adaptive immunity. Consequently, in the last two decades mounting evidence has inextricably linked TLR activation with the pathogenesis of immune diseases and cancer. It has become advantageous to harness these aspects of TLR signaling therapeutically to accelerate and enhance the induction of vaccine-specific responses and also target TLRs with the use of biologics and small molecule inhibitors for the treatment of disease. In these respects, TLRs may be considered a 'Swiss Army' knife of the immune system, ready to respond in a multitude of infectious and disease states. Here we describe the latest advances in TLR-targeted therapeutics and the use of TLR ligands as vaccine adjuvants.
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Affiliation(s)
- Jennifer K Dowling
- Pattern Recognition Receptors and Inflammation Research group, Centre for Innate Immunity and Infectious Disease, Hudson Institute of Medical Research, Melbourne, Victoria, Australia; Monash University, Clayton, Victoria, Australia
| | - Ashley Mansell
- Pattern Recognition Receptors and Inflammation Research group, Centre for Innate Immunity and Infectious Disease, Hudson Institute of Medical Research, Melbourne, Victoria, Australia; Monash University, Clayton, Victoria, Australia
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Z-100, extracted from Mycobacterium tuberculosis strain Aoyama B, promotes TNF-α production via nucleotide-binding oligomerization domain containing 2 (Nod2)-dependent NF-κB activation in RAW264.7 cells. Mol Immunol 2015; 64:218-27. [DOI: 10.1016/j.molimm.2014.11.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 11/20/2014] [Accepted: 11/25/2014] [Indexed: 01/07/2023]
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Elass-Rochard E, Rombouts Y, Coddeville B, Maes E, Blervaque R, Hot D, Kremer L, Guérardel Y. Structural determination and Toll-like receptor 2-dependent proinflammatory activity of dimycolyl-diarabino-glycerol from Mycobacterium marinum. J Biol Chem 2012; 287:34432-44. [PMID: 22798072 DOI: 10.1074/jbc.m112.378083] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Although it was identified in the cell wall of several pathogenic mycobacteria, the biological properties of dimycolyl-diarabino-glycerol have not been documented yet. In this study an apolar glycolipid, presumably corresponding to dimycolyl-diarabino-glycerol, was purified from Mycobacterium marinum and subsequently identified as a 5-O-mycolyl-β-Araf-(1→2)-5-O-mycolyl-α-Araf-(1→1')-glycerol (designated Mma_DMAG) using a combination of nuclear magnetic resonance spectroscopy and mass spectrometry analyses. Lipid composition analysis revealed that mycolic acids were dominated by oxygenated mycolates over α-mycolates and devoid of trans-cyclopropane functions. Highly purified Mma_DMAG was used to demonstrate its immunomodulatory activity. Mma_DMAG was found to induce the secretion of proinflammatory cytokines (TNF-α, IL-8, IL-1β) in human macrophage THP-1 cells and to trigger the expression of ICAM-1 and CD40 cell surface antigens. This activation mechanism was dependent on TLR2, but not on TLR4, as demonstrated by (i) the use of neutralizing anti-TLR2 and -TLR4 antibodies and by (ii) the detection of secreted alkaline phosphatase in HEK293 cells co-transfected with the human TLR2 and secreted embryonic alkaline phosphatase reporter genes. In addition, transcriptomic analyses indicated that various genes encoding proinflammatory factors were up-regulated after exposure of THP-1 cells to Mma_DMAG. Importantly, a wealth of other regulated genes related to immune and inflammatory responses, including chemokines/cytokines and their respective receptors, adhesion molecules, and metalloproteinases, were found to be modulated by Mma_DMAG. Overall, this study suggests that DMAG may be an active cell wall glycoconjugate driving host-pathogen interactions and participating in the immunopathogenesis of mycobacterial infections.
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Affiliation(s)
- Elisabeth Elass-Rochard
- Université Lille Nord de France, Université Lille1, Unité de Glycobiologie Structurale et Fonctionnelle, UGSF, IFR 147, France.
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Connolly DJ, O'Neill LAJ. New developments in Toll-like receptor targeted therapeutics. Curr Opin Pharmacol 2012; 12:510-8. [PMID: 22748800 DOI: 10.1016/j.coph.2012.06.002] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2012] [Accepted: 06/06/2012] [Indexed: 02/06/2023]
Abstract
Toll-like receptors (TLRs) play a crucial role in host defence and inflammation. Given that a significant amount of evidence implicates TLRs in the pathogenesis of immune diseases and cancer, and their activation occurs early in the inflammatory cascade, they are attractive targets for novel therapeutic agents. Potential therapeutics include TLR-targeted antibodies, small molecules and nucleic acid based drugs. Agonists are being tested in vaccines against hepatitis C and influenza as well as in allergic rhinitis and certain cancers. Antagonists are being tested in ischemia/reperfusion injury, systemic lupus erythematosus and psoriasis. The prospect of targeting TLRs in multiple pathologies continues to hold much promise.
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Affiliation(s)
- Dympna J Connolly
- Trinity Biomedical Sciences Institute, School of Biochemistry and Immunology, Trinity College Dublin, Dublin 2, Ireland
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