1
|
Jeyasankar S, Kalapala YC, Sharma PR, Agarwal R. Antibacterial efficacy of mycobacteriophages against virulent Mycobacterium tuberculosis. BMC Microbiol 2024; 24:320. [PMID: 39227770 PMCID: PMC11373169 DOI: 10.1186/s12866-024-03474-3] [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: 07/15/2024] [Accepted: 08/23/2024] [Indexed: 09/05/2024] Open
Abstract
Tuberculosis (TB) remains a major global health concern, with drug-resistant strains posing a significant challenge to effective treatment. Bacteriophage (phage) therapy has emerged as a potential alternative to combat antibiotic resistance. In this study, we investigated the efficacy of widely used mycobacteriophages (D29, TM4, DS6A) against Mycobacterium tuberculosis (M. tuberculosis) under pathophysiological conditions associated with TB, such as low pH and hypoxia. We found that even at low multiplicity of infection (MOI), mycobacteriophages effectively infected M. tuberculosis, got rapidly amplified, and lysed M. tuberculosis, demonstrating their potential as therapeutic agents. Furthermore, we observed a novel phage tolerance mechanism with bacteria forming aggregates after several days of phage treatment. These aggregates were enriched with biofilm components and metabolically active bacteria. However, no phage tolerance was observed upon treatment with the three-phage mixture, highlighting the dynamic interplay between phages and bacteria and emphasizing the importance of phage cocktails. We also observed that phages were effective in lysing bacteria even under low pH and low oxygen concentrations as well as antibiotic-resistant bacteria. Our results provide key insights into phage infection of slow-growing bacteria and suggest that mycobacteriophages can effectively eliminate M. tuberculosis in complex pathophysiological environments like hypoxia and acidic pH. These results can aid in developing targeted phage-based therapies to combat antibiotic-resistant mycobacterial infections.
Collapse
Affiliation(s)
| | | | - Pallavi Raj Sharma
- Department of Bioengineering, Indian Institute of Science, Bengaluru, India
| | - Rachit Agarwal
- Department of Bioengineering, Indian Institute of Science, Bengaluru, India.
| |
Collapse
|
2
|
Wang TT, Hu YL, Li YF, Kong XL, Li YM, Sun PY, Wang DX, Li YY, Zhang YZ, Han QL, Zhu XH, An QQ, Liu LL, Liu Y, Li HC. Polyketide synthases mutation in tuberculosis transmission revealed by whole genomic sequence, China, 2011-2019. Front Genet 2024; 14:1217255. [PMID: 38259610 PMCID: PMC10800454 DOI: 10.3389/fgene.2023.1217255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Accepted: 11/30/2023] [Indexed: 01/24/2024] Open
Abstract
Introduction: Tuberculosis (TB) is an infectious disease caused by a bacterium called Mycobacterium tuberculosis (Mtb). Previous studies have primarily focused on the transmissibility of multidrug-resistant (MDR) or extensively drug-resistant (XDR) Mtb. However, variations in virulence across Mtb lineages may also account for differences in transmissibility. In Mtb, polyketide synthase (PKS) genes encode large multifunctional proteins which have been shown to be major mycobacterial virulence factors. Therefore, this study aimed to identify the role of PKS mutations in TB transmission and assess its risk and characteristics. Methods: Whole genome sequences (WGSs) data from 3,204 Mtb isolates was collected from 2011 to 2019 in China. Whole genome single nucleotide polymorphism (SNP) profiles were used for phylogenetic tree analysis. Putative transmission clusters (≤10 SNPs) were identified. To identify the role of PKS mutations in TB transmission, we compared SNPs in the PKS gene region between "clustered isolates" and "non-clustered isolates" in different lineages. Results: Cluster-associated mutations in ppsA, pks12, and pks13 were identified among different lineage isolates. They were statistically significant among clustered strains, indicating that they may enhance the transmissibility of Mtb. Conclusion: Overall, this study provides new insights into the function of PKS and its localization in M. tuberculosis. The study found that ppsA, pks12, and pks13 may contribute to disease progression and higher transmission of certain strains. We also discussed the prospective use of mutant ppsA, pks12, and pks13 genes as drug targets.
Collapse
Affiliation(s)
- Ting-Ting Wang
- Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Yuan-Long Hu
- Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Yi-Fan Li
- Department of Pulmonary and Critical Care Medicine, The Third Affiliated Hospital of Shandong First Medical University (Affiliated Hospital of Shandong Academy of Medical Sciences), Jinan, China
| | - Xiang-Long Kong
- Shandong Artificial Intelligence Institute Qilu University of Technology (Shandong Academy of Sciences), Jinan, China
| | - Ya-Meng Li
- Shandong University of Traditional Chinese Medicine, Jinan, China
| | | | - Da-Xing Wang
- People’s Hospital of Huaiyin Jinan, Jinan, China
| | - Ying-Ying Li
- Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Yu-Zhen Zhang
- Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China
| | - Qi-Lin Han
- Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China
| | - Xue-Han Zhu
- Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China
| | - Qi-Qi An
- Department of Respiratory and Critical Care Medicine, Shandong Provincial Hospital Affiliated to 11 Shandong University, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
| | - Li-Li Liu
- People’s Hospital of Huaiyin Jinan, Jinan, China
| | - Yao Liu
- Department of Respiratory and Critical Care Medicine, Shandong Provincial Hospital Affiliated to 11 Shandong University, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
| | - Huai-Chen Li
- Shandong University of Traditional Chinese Medicine, Jinan, China
- Department of Respiratory and Critical Care Medicine, Shandong Provincial Hospital Affiliated to 11 Shandong University, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
| |
Collapse
|
3
|
Srivatsav AT, Kapoor S. Biophysical Interaction Landscape of Mycobacterial Mycolic Acids and Phenolic Glycolipids with Host Macrophage Membranes. ACS APPLIED BIO MATERIALS 2023; 6:5555-5562. [PMID: 38015441 DOI: 10.1021/acsabm.3c00748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Lipidic adjuvant formulations consisting of immunomodulatory mycobacterial cell wall lipids interact with host cells following administration. The impact of this cross-talk on the host membrane's structure and function is rarely given enough consideration but is imperative to rule out nonspecific perturbation underlying the adjuvant. In this work, we investigated changes in the plasma membranes of live mammalian cells after exposure to mycobacterial mycolic acid (MA) and phenolic glycolipids, two strong candidates for lipidic adjuvant therapy. We found that phenolic glycolipid 1 softened the plasma membrane, lowering membrane tension and stiffness, but MA did not significantly change the membrane characteristics. Further, phenolic glycolipid 1 had a fluidizing impact on the host plasma membrane, increasing the fluidity and the abundance of fluid-ordered-disordered coexisting lipid domains. Notably, lipid diffusion was not impacted. Overall, MA and, to a lesser extent, phenolic glycolipid 1, due to minor disruption of host cell membranes, may serve as appropriate lipids in adjuvant formulations.
Collapse
Affiliation(s)
- Aswin T Srivatsav
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Shobhna Kapoor
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| |
Collapse
|
4
|
Kumar M, Virmani T, Kumar G, Deshmukh R, Sharma A, Duarte S, Brandão P, Fonte P. Nanocarriers in Tuberculosis Treatment: Challenges and Delivery Strategies. Pharmaceuticals (Basel) 2023; 16:1360. [PMID: 37895831 PMCID: PMC10609727 DOI: 10.3390/ph16101360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 09/18/2023] [Accepted: 09/20/2023] [Indexed: 10/29/2023] Open
Abstract
The World Health Organization identifies tuberculosis (TB), caused by Mycobacterium tuberculosis, as a leading infectious killer. Although conventional treatments for TB exist, they come with challenges such as a heavy pill regimen, prolonged treatment duration, and a strict schedule, leading to multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains. The rise of MDR strains endangers future TB control. Despite these concerns, the hunt for an efficient treatment continues. One breakthrough has been the use of nanotechnology in medicines, presenting a novel approach for TB treatment. Nanocarriers, such as lipid nanoparticles, nanosuspensions, liposomes, and polymeric micelles, facilitate targeted delivery of anti-TB drugs. The benefits of nanocarriers include reduced drug doses, fewer side effects, improved drug solubility, better bioavailability, and improved patient compliance, speeding up recovery. Additionally, nanocarriers can be made even more targeted by linking them with ligands such as mannose or hyaluronic acid. This review explores these innovative TB treatments, including studies on nanocarriers containing anti-TB drugs and related patents.
Collapse
Affiliation(s)
- Mahesh Kumar
- School of Pharmaceutical Sciences, Modern Vidya Niketan University, Palwal 121105, India; (M.K.); (G.K.); (A.S.)
| | - Tarun Virmani
- School of Pharmaceutical Sciences, Modern Vidya Niketan University, Palwal 121105, India; (M.K.); (G.K.); (A.S.)
| | - Girish Kumar
- School of Pharmaceutical Sciences, Modern Vidya Niketan University, Palwal 121105, India; (M.K.); (G.K.); (A.S.)
| | - Rohitas Deshmukh
- Institute of Pharmaceutical Research, GLA University, Mathura 281406, India;
| | - Ashwani Sharma
- School of Pharmaceutical Sciences, Modern Vidya Niketan University, Palwal 121105, India; (M.K.); (G.K.); (A.S.)
| | - Sofia Duarte
- iBB—Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, University of Lisboa, 1049-001 Lisbon, Portugal; (S.D.); (P.B.)
- Associate Laboratory i4HB—Institute for Health and Bio-Economy, Instituto Superior Técnico, University of Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - Pedro Brandão
- iBB—Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, University of Lisboa, 1049-001 Lisbon, Portugal; (S.D.); (P.B.)
- Associate Laboratory i4HB—Institute for Health and Bio-Economy, Instituto Superior Técnico, University of Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
- Egas Moniz Center for Interdisciplinary Research (CiiEM), Egas Moniz School of Health & Science, 2829-511 Almada, Portugal
- CQC-IMS, Department of Chemistry, University of Coimbra, Rua Larga, 3004-535 Coimbra, Portugal
| | - Pedro Fonte
- iBB—Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, University of Lisboa, 1049-001 Lisbon, Portugal; (S.D.); (P.B.)
- Associate Laboratory i4HB—Institute for Health and Bio-Economy, Instituto Superior Técnico, University of Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
- Center for Marine Sciences (CCMar), University of Algarve, Gambelas Campus, 8005-139 Faro, Portugal
- Department of Chemistry and Pharmacy, Faculty of Sciences and Technology, University of Algarve, Gambelas Campus, 8005-139 Faro, Portugal
| |
Collapse
|
5
|
Liu Y, Kaffah N, Pandor S, Sartain MJ, Larrouy-Maumus G. Ion mobility mass spectrometry for the study of mycobacterial mycolic acids. Sci Rep 2023; 13:10390. [PMID: 37369807 DOI: 10.1038/s41598-023-37641-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 06/25/2023] [Indexed: 06/29/2023] Open
Abstract
Lipids are highly structurally diverse molecules involved in a wide variety of biological processes. The involvement of lipids is even more pronounced in mycobacteria, including the human pathogen Mycobacterium tuberculosis, which produces a highly complex and diverse set of lipids in the cell envelope. These lipids include mycolic acids, which are among the longest fatty acids in nature and can contain up to 90 carbon atoms. Mycolic acids are ubiquitously found in mycobacteria and are alpha branched and beta hydroxylated lipids. Discrete modifications, such as alpha, alpha', epoxy, methoxy, keto, and carboxy, characterize mycolic acids at the species level. Here, we used high precision ion mobility-mass spectrometry to build a database including 206 mass-resolved collision cross sections (CCSs) of mycolic acids originating from the strict human pathogen M. tuberculosis, the opportunistic strains M. abscessus, M. marinum and M. avium, and the nonpathogenic strain M. smegmatis. Primary differences between the mycolic acid profiles could be observed between mycobacterial species. Acyl tail length and modifications were the primary structural descriptors determining CCS magnitude. As a resource for researchers, this work provides a detailed catalogue of the mass-resolved collision cross sections for mycolic acids along with a workflow to generate and analyse the dataset generated.
Collapse
Affiliation(s)
- Yi Liu
- Centre for Bacterial Resistance Biology, Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, SW7 2AZ, UK
| | - Nadhira Kaffah
- Centre for Bacterial Resistance Biology, Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, SW7 2AZ, UK
| | | | | | - Gerald Larrouy-Maumus
- Centre for Bacterial Resistance Biology, Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, SW7 2AZ, UK.
| |
Collapse
|
6
|
Wang K, Deng Y, Cui X, Chen M, Ou Y, Li D, Guo M, Li W. PatA Regulates Isoniazid Resistance by Mediating Mycolic Acid Synthesis and Controls Biofilm Formation by Affecting Lipid Synthesis in Mycobacteria. Microbiol Spectr 2023; 11:e0092823. [PMID: 37212713 PMCID: PMC10269662 DOI: 10.1128/spectrum.00928-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 05/09/2023] [Indexed: 05/23/2023] Open
Abstract
Lipids are prominent components of the mycobacterial cell wall, and they play critical roles not only in maintaining biofilm formation but also in resisting environmental stress, including drug resistance. However, information regarding the mechanism mediating mycobacterial lipid synthesis remains limited. PatA is a membrane-associated acyltransferase and synthesizes phosphatidyl-myo-inositol mannosides (PIMs) in mycobacteria. Here, we found that PatA could regulate the synthesis of lipids (except mycolic acids) to maintain biofilm formation and environmental stress resistance in Mycolicibacterium smegmatis. Interestingly, the deletion of patA significantly enhanced isoniazid (INH) resistance in M. smegmatis, although it reduced bacterial biofilm formation. This might be due to the fact that the patA deletion promoted the synthesis of mycolic acids through an unknown synthesis pathway other than the reported fatty acid synthase (FAS) pathway, which could effectively counteract the inhibition by INH of mycolic acid synthesis in mycobacteria. Furthermore, the amino acid sequences and physiological functions of PatA were highly conserved in mycobacteria. Therefore, we found a mycolic acid synthesis pathway regulated by PatA in mycobacteria. In addition, PatA also affected biofilm formation and environmental stress resistance by regulating the synthesis of lipids (except mycolic acids) in mycobacteria. IMPORTANCE Tuberculosis, caused by Mycobacterium tuberculosis, leads to a large number of human deaths every year. This is so serious, which is due mainly to the drug resistance of mycobacteria. INH kills M. tuberculosis by inhibiting the synthesis of mycolic acids, which are synthesized by the FAS pathway. However, whether there is another mycolic acid synthesis pathway is unknown. In this study, we found a PatA-mediated mycolic acid synthesis pathway that led to INH resistance of in patA-deleted mutant. In addition, we first report the regulatory effect of PatA on mycobacterial biofilm formation, which could affect the bacterial response to environmental stress. Our findings represent a new model for regulating biofilm formation by mycobacteria. More importantly, the discovery of the PatA-mediated mycolic acid synthesis pathway indicates that the study of mycobacterial lipids has entered a new stage, and the enzymes might be new targets of antituberculosis drugs.
Collapse
Affiliation(s)
- Kun Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Yimin Deng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Xujie Cui
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Mengli Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Yanzhe Ou
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Danting Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Minhao Guo
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Weihui Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| |
Collapse
|
7
|
Hailu E, Cantillon D, Madrazo C, Rose G, Wheeler PR, Golby P, Adnew B, Gagneux S, Aseffa A, Gordon SV, Comas I, Young DB, Waddell SJ, Larrouy-Maumus G, Berg S. Lack of methoxy-mycolates characterizes the geographically restricted lineage 7 of Mycobacterium tuberculosis complex. Microb Genom 2023; 9. [PMID: 37171244 PMCID: PMC10272862 DOI: 10.1099/mgen.0.001011] [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] [Indexed: 05/13/2023] Open
Abstract
Lineage 7 (L7) emerged in the phylogeny of the Mycobacterium tuberculosis complex (MTBC) subsequent to the branching of 'ancient' lineage 1 and prior to the Eurasian dispersal of 'modern' lineages 2, 3 and 4. In contrast to the major MTBC lineages, the current epidemiology suggests that prevalence of L7 is highly confined to the Ethiopian population, or when identified outside of Ethiopia, it has mainly been in patients of Ethiopian origin. To search for microbiological factors that may contribute to its restricted distribution, we compared the genome of L7 to the genomes of globally dispersed MTBC lineages. The frequency of predicted functional mutations in L7 was similar to that documented in other lineages. These include mutations characteristic of modern lineages - such as constitutive expression of nitrate reductase - as well as mutations in the VirS locus that are commonly found in ancient lineages. We also identified and characterized multiple lineage-specific mutations in L7 in biosynthesis pathways of cell wall lipids, including confirmed deficiency of methoxy-mycolic acids due to a stop-gain mutation in the mmaA3 gene that encodes a methoxy-mycolic acid synthase. We show that the abolished biosynthesis of methoxy-mycolates of L7 alters the cell structure and colony morphology on selected growth media and impacts biofilm formation. The loss of these mycolic acid moieties may change the host-pathogen dynamic for L7 isolates, explaining the limited geographical distribution of L7 and contributing to further understanding the spread of MTBC lineages across the globe.
Collapse
Affiliation(s)
- Elena Hailu
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Daire Cantillon
- Present address: Department of Tropical Biology, Liverpool School of Tropical Medicine, Liverpool, UK
- Brighton and Sussex Centre for Global Health Research, Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Falmer, UK
| | - Carlos Madrazo
- Biomedicine Institute of Valencia, Spanish Research Council (IBV-CSIC), Valencia, Spain
| | - Graham Rose
- Present address: North Thames Genomic Laboratory Hub, Great Ormond Street Hospital for Children, London, UK
- Francis Crick Institute, London, UK
| | | | - Paul Golby
- Animal and Plant Health Agency, Weybridge, UK
| | | | - Sebastien Gagneux
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Abraham Aseffa
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Stephen V Gordon
- School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - Iñaki Comas
- Biomedicine Institute of Valencia, Spanish Research Council (IBV-CSIC), Valencia, Spain
| | - Douglas B Young
- Francis Crick Institute, London, UK
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Simon J Waddell
- Brighton and Sussex Centre for Global Health Research, Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Falmer, UK
| | - Gerald Larrouy-Maumus
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Stefan Berg
- Present address: Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Animal and Plant Health Agency, Weybridge, UK
| |
Collapse
|
8
|
Kumar G, Kapoor S. Targeting mycobacterial membranes and membrane proteins: Progress and limitations. Bioorg Med Chem 2023; 81:117212. [PMID: 36804747 DOI: 10.1016/j.bmc.2023.117212] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 02/06/2023] [Accepted: 02/08/2023] [Indexed: 02/13/2023]
Abstract
Among the various bacterial infections, tuberculosis continues to hold center stage. Its causative agent, Mycobacterium tuberculosis, possesses robust defense mechanisms against most front-line antibiotic drugs and host responses due to their complex cell membranes with unique lipid molecules. It is now well-established that bacteria change their membrane composition to optimize their environment to survive and elude drug action. Thus targeting membrane or membrane components is a promising avenue for exploiting the chemical space focussed on developing novel membrane-centric anti-bacterial small molecules. These approaches are more effective, non-toxic, and can attenuate resistance phenotype. We present the relevance of targeting the mycobacterial membrane as a practical therapeutic approach. The review highlights the direct and indirect targeting of membrane structure and function. Direct membrane targeting agents cause perturbation in the membrane potential and can cause leakage of the cytoplasmic contents. In contrast, indirect membrane targeting agents disrupt the function of membrane-associated proteins involved in cell wall biosynthesis or energy production. We discuss the chronological chemical improvements in various scaffolds targeting specific membrane-associated protein targets, their clinical evaluation, and up-to-date account of their ''mechanisms of action, potency, selectivity'' and limitations. The sources of anti-TB drugs/inhibitors discussed in this work have emerged from target-based identification, cell-based phenotypic screening, drug repurposing, and natural products. We believe this review will inspire the exploration of uncharted chemical space for informing the development of new scaffolds that can inhibit novel mycobacterial membrane targets.
Collapse
Affiliation(s)
- Gautam Kumar
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India; Departemnt of Natural Products, National Institute of Pharmaceutical Education and Research-Hyderabad, Hyderabad 500037, India.
| | - Shobhna Kapoor
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India; Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima 739-8528, Japan.
| |
Collapse
|
9
|
Paik S, Kim KT, Kim IS, Kim YJ, Kim HJ, Choi S, Kim HJ, Jo EK. Mycobacterial acyl carrier protein suppresses TFEB activation and upregulates miR-155 to inhibit host defense. Front Immunol 2022; 13:946929. [PMID: 36248815 PMCID: PMC9559204 DOI: 10.3389/fimmu.2022.946929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 09/07/2022] [Indexed: 11/29/2022] Open
Abstract
Mycobacterial acyl carrier protein (AcpM; Rv2244), a key protein involved in Mycobacterium tuberculosis (Mtb) mycolic acid production, has been shown to suppress host cell death during mycobacterial infection. This study reports that mycobacterial AcpM works as an effector to subvert host defense and promote bacterial growth by increasing microRNA (miRNA)-155-5p expression. In murine bone marrow-derived macrophages (BMDMs), AcpM protein prevented transcription factor EB (TFEB) from translocating to the nucleus in BMDMs, which likely inhibited transcriptional activation of several autophagy and lysosomal genes. Although AcpM did not suppress autophagic flux in BMDMs, AcpM reduced Mtb and LAMP1 co-localization indicating that AcpM inhibits phagolysosomal fusion during Mtb infection. Mechanistically, AcpM boosted the Akt-mTOR pathway in BMDMs by upregulating miRNA-155-5p, a SHIP1-targeting miRNA. When miRNA-155-5p expression was inhibited in BMDMs, AcpM-induced increased intracellular survival of Mtb was suppressed. In addition, AcpM overexpression significantly reduced mycobacterial clearance in C3HeB/FeJ mice infected with recombinant M. smegmatis strains. Collectively, our findings point to AcpM as a novel mycobacterial effector to regulate antimicrobial host defense and a potential new therapeutic target for Mtb infection.
Collapse
Affiliation(s)
- Seungwha Paik
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, South Korea
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon, South Korea
- *Correspondence: Seungwha Paik, ; Eun-Kyeong Jo,
| | - Kyeong Tae Kim
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, South Korea
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon, South Korea
- Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, South Korea
| | - In Soo Kim
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, South Korea
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon, South Korea
- Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, South Korea
| | - Young Jae Kim
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, South Korea
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon, South Korea
- Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, South Korea
| | - Hyeon Ji Kim
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, South Korea
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon, South Korea
- Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, South Korea
| | - Seunga Choi
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, South Korea
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon, South Korea
| | - Hwa-Jung Kim
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, South Korea
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon, South Korea
- Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, South Korea
| | - Eun-Kyeong Jo
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, South Korea
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon, South Korea
- Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, South Korea
- *Correspondence: Seungwha Paik, ; Eun-Kyeong Jo,
| |
Collapse
|
10
|
Schieferdecker S, Bernal FA, Wojtas KP, Keiff F, Li Y, Dahse HM, Kloss F. Development of Predictive Classification Models for Whole Cell Antimycobacterial Activity of Benzothiazinones. J Med Chem 2022; 65:6748-6763. [PMID: 35502994 DOI: 10.1021/acs.jmedchem.2c00098] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Nitrobenzothiazinones (BTZs) are a very potent class of antibiotics against Mycobacterium tuberculosis. However, relationships between their structural properties and whole cell activity remain poorly predictable. Herein, we present the synthesis and antimycobacterial evaluation of a diverse set of BTZs. High potency was predominantly achieved by piperidine and piperazine substitutions, whereupon three compounds were identified as promising candidates, showing preferable metabolic stability. Lack of correlation between potency and calculated binding energies suggested that target inhibition is not the only requirement to obtain suitable antimycobacterial agents. In contrast, prediction of whole cell activity class was successfully accomplished by extensively validated machine learning models. The performance of the superior model was further verified by >70% correct class predictions for a large set of reported BTZs. Our generated model is thus a key prerequisite to streamline lead optimization endeavors, particularly regarding the improvement of overall hit rates in whole cell antimycobacterial assays.
Collapse
Affiliation(s)
- Sebastian Schieferdecker
- Transfer Group Anti-infectives, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Beutenbergstr. 11a, 07745 Jena, Germany
| | - Freddy A Bernal
- Transfer Group Anti-infectives, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Beutenbergstr. 11a, 07745 Jena, Germany
| | - K Philip Wojtas
- Transfer Group Anti-infectives, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Beutenbergstr. 11a, 07745 Jena, Germany
| | - François Keiff
- Transfer Group Anti-infectives, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Beutenbergstr. 11a, 07745 Jena, Germany
| | - Yan Li
- Transfer Group Anti-infectives, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Beutenbergstr. 11a, 07745 Jena, Germany
| | - Hans-Martin Dahse
- Department Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Beutenbergstr. 11a, 07745 Jena, Germany
| | - Florian Kloss
- Transfer Group Anti-infectives, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Beutenbergstr. 11a, 07745 Jena, Germany
| |
Collapse
|
11
|
Noda J, Tomizawa S, Takahashi K, Morimoto K, Mitarai S. Air pollution and airborne infection with mycobacterial bioaerosols: a potential attribution of soot. INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY : IJEST 2022; 19:717-726. [PMID: 33643419 PMCID: PMC7897364 DOI: 10.1007/s13762-021-03203-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 01/10/2021] [Accepted: 01/28/2021] [Indexed: 05/07/2023]
Abstract
Atmospheric pollutants are hypothesized to enhance the viability of airborne microbes by preventing them from degradation processes, thereby enhancing their atmospheric survival. In this study, Mycobacterium smegmatis is used as a model airborne bacteria, and different amounts of soot particles are employed as model air pollutants. The toxic effects of soot on aerosolized M. smegmatis are first evaluated and excluded by introducing them separately into a chamber, being sampled on a filter, and then cultured and counted. Secondly, the bacteria-soot mixture is exposed to UV with different durations and then cultured for bacterial viability evaluations. The results show that under UV exposure, the survival rates of the low-, medium-, and high-soot groups are 1.1 (±0.8) %, 70.9 (±4.3) %, and 61.0 (±17.6) %, respectively. This evidence significantly enhanced survival rates by soot at all UV exposures, though the combinations of UV exposure and soot amounts revealed a changing pattern of survival rates. The possible influence by direct and indirect effects of UV-damaging mechanisms is proposed. This study indicates the soot-induced survival rate enhancements of M. smegmatis under UV stress conditions, representing the possible relations between air pollution and the extended pathogenic viability and, therefore, increased airborne infection probability.
Collapse
Affiliation(s)
- J. Noda
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido Japan
| | - S. Tomizawa
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido Japan
| | - K. Takahashi
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido Japan
| | - K. Morimoto
- Division of Clinical Research, Fukujuji Hospital, Japan Anti-Tuberculosis Association, Tokyo, Japan
- Department of Mycobacterium Reference and Research, Research Institute of Tuberculosis Japan Anti-Tuberculosis Association, Tokyo, Japan
| | - S. Mitarai
- Department of Mycobacterium Reference and Research, Research Institute of Tuberculosis Japan Anti-Tuberculosis Association, Tokyo, Japan
| |
Collapse
|
12
|
Wu X, Wu Y, Zheng R, Tang F, Qin L, Lai D, Zhang L, Chen L, Yan B, Yang H, Wang Y, Li F, Zhang J, Wang F, Wang L, Cao Y, Ma M, Liu Z, Chen J, Huang X, Wang J, Jin R, Wang P, Sun Q, Sha W, Lyu L, Moura‐Alves P, Dorhoi A, Pei G, Zhang P, Chen J, Gao S, Randow F, Zeng G, Chen C, Ye X, Kaufmann SHE, Liu H, Ge B. Sensing of mycobacterial arabinogalactan by galectin-9 exacerbates mycobacterial infection. EMBO Rep 2021; 22:e51678. [PMID: 33987949 PMCID: PMC8256295 DOI: 10.15252/embr.202051678] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 04/10/2021] [Accepted: 04/16/2021] [Indexed: 12/14/2022] Open
Abstract
Mycobacterial arabinogalactan (AG) is an essential cell wall component of mycobacteria and a frequent structural and bio-synthetical target for anti-tuberculosis (TB) drug development. Here, we report that mycobacterial AG is recognized by galectin-9 and exacerbates mycobacterial infection. Administration of AG-specific aptamers inhibits cellular infiltration caused by Mycobacterium tuberculosis (Mtb) or Mycobacterium bovis BCG, and moderately increases survival of Mtb-infected mice or Mycobacterium marinum-infected zebrafish. AG interacts with carbohydrate recognition domain (CRD) 2 of galectin-9 with high affinity, and galectin-9 associates with transforming growth factor β-activated kinase 1 (TAK1) via CRD2 to trigger subsequent activation of extracellular signal-regulated kinase (ERK) as well as induction of the expression of matrix metalloproteinases (MMPs). Moreover, deletion of galectin-9 or inhibition of MMPs blocks AG-induced pathological impairments in the lung, and the AG-galectin-9 axis aggravates the process of Mtb infection in mice. These results demonstrate that AG is an important virulence factor of mycobacteria and galectin-9 is a novel receptor for Mtb and other mycobacteria, paving the way for the development of novel effective TB immune modulators.
Collapse
|
13
|
Aitken JM, Phan K, Bodman SE, Sharma S, Watt A, George PM, Agrawal G, Tie ABM. A Mycobacterium species for Crohn's disease? Pathology 2021; 53:818-823. [PMID: 34158180 DOI: 10.1016/j.pathol.2021.03.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 02/18/2021] [Accepted: 03/03/2021] [Indexed: 12/13/2022]
Abstract
In ruminants Mycobacterium avium subspecies paratuberculosis (MAP) is the causative organism of a chronic granulomatous inflammatory bowel disease called Johne's disease (JD). Some researchers have hypothesised that MAP is also associated with Crohn's disease (CD), an inflammatory bowel disease in humans that shares some histological features of JD. Despite numerous attempts to demonstrate causality by researchers, direct microbiological evidence of MAP involvement in CD remains elusive. Importantly, it has not been possible to reliably and reproducibly demonstrate mycobacteria in the tissue of CD patients. Past attempts to visualise mycobacteria in tissue may have been hampered by the use of stains optimised for Mycobacterium tuberculosis complex (MTB) and the lack of reliable bacteriological culture media for both non-tuberculous mycobacteria (NTM) and cell-wall-deficient mycobacteria (CWDM). Here we describe a Ziehl-Neelsen (ZN) staining method for the demonstration of CWDM in resected tissue from patients with Crohn's disease, revealing the association of CWDM in situ with host tissue reactions, and posit this as a cause of the tissue inflammation. Using the ZN stain described we demonstrated the presence of CWDM in 18 out of 18 excised tissue samples from patients diagnosed as having Crohn's disease, and in zero samples out of 15 non-inflammatory bowel disease controls.
Collapse
Affiliation(s)
| | - Khoi Phan
- Southern Community Laboratories, Wellington Hospital, Wellington, New Zealand
| | | | | | | | | | - Gaurav Agrawal
- Guy's and St Thomas' Hospitals NHS Foundation Trust, Kings College, London, UK
| | - Andrew B M Tie
- Southern Community Laboratories, Wellington Hospital, Wellington, New Zealand
| |
Collapse
|
14
|
TREM2 is a receptor for non-glycosylated mycolic acids of mycobacteria that limits anti-mycobacterial macrophage activation. Nat Commun 2021; 12:2299. [PMID: 33863908 PMCID: PMC8052348 DOI: 10.1038/s41467-021-22620-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 03/17/2021] [Indexed: 01/10/2023] Open
Abstract
Mycobacterial cell-wall glycolipids elicit an anti-mycobacterial immune response via FcRγ-associated C-type lectin receptors, including Mincle, and caspase-recruitment domain family member 9 (CARD9). Additionally, mycobacteria harbor immuno-evasive cell-wall lipids associated with virulence and latency; however, a mechanism of action is unclear. Here, we show that the DAP12-associated triggering receptor expressed on myeloid cells 2 (TREM2) recognizes mycobacterial cell-wall mycolic acid (MA)-containing lipids and suggest a mechanism by which mycobacteria control host immunity via TREM2. Macrophages respond to glycosylated MA-containing lipids in a Mincle/FcRγ/CARD9-dependent manner to produce inflammatory cytokines and recruit inducible nitric oxide synthase (iNOS)-positive mycobactericidal macrophages. Conversely, macrophages respond to non-glycosylated MAs in a TREM2/DAP12-dependent but CARD9-independent manner to recruit iNOS-negative mycobacterium-permissive macrophages. Furthermore, TREM2 deletion enhances Mincle-induced macrophage activation in vitro and inflammation in vivo and accelerates the elimination of mycobacterial infection, suggesting that TREM2-DAP12 signaling counteracts Mincle-FcRγ-CARD9-mediated anti-mycobacterial immunity. Mycobacteria, therefore, harness TREM2 for immune evasion. Mycobacterial cell wall lipids can drive immunoevasion, but underlying mechanisms are incompletely understood. Here the authors show TREM2 is a pattern recognition receptor that binds non-glycosylated mycolic acid-containing lipids and inhibits Mincle-induced anti-mycobacterial macrophage responses.
Collapse
|
15
|
Jones A, Davies CA, Fitch S, Al Dulayymi JR, Gwenin CD, Gibbons J, Williams AP, Baird MS. Elevated serum antibody responses to synthetic mycobacterial lipid antigens among UK farmers: an indication of exposure to environmental mycobacteria? RSC Med Chem 2021; 12:213-221. [PMID: 34046610 PMCID: PMC8128033 DOI: 10.1039/d0md00325e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 10/28/2020] [Indexed: 11/21/2022] Open
Abstract
Background: mycobacterial cells contain complex mixtures of mycolic acid esters. These can be used as antigens recognised by antibodies in the serum of individuals with active tuberculosis, caused by Mycobacterium tuberculosis. In high burden populations, a significant number of false positives are observed; possibly these antigens are also recognised by antibodies generated by other mycobacterial infections, particularly ubiquitous 'environmental mycobacteria'. This suggests similar responses may be observed in a low burden TB population, particularly in groups regularly exposed to mycobacteria. Methods: ELISA using single synthetic trehalose mycolates corresponding to major classes in many mycobacteria was used to detect antibodies in serum of individuals with no known mycobacterial infection, comprising farmers, abattoir workers, and rural and urban populations. Results: serum from four Welsh or Scottish cohorts showed lower (with some antigens significantly lower) median responses than those reported for TB negatives from high-burden TB populations, and significantly lower responses than those with active TB. A small fraction, particularly older farmers, showed strong responses. A second study examined BCG vaccinated and non-vaccinated farmers and non-farmers. Farmers gave significantly higher median responses than non-farmers with three of five antigens, while there was no significant difference between vaccinated or non-vaccinated for either farmer or non-farmer groups. Conclusions: this initial study shows that serodiagnosis with mycobacterial lipid antigens can detect antibodies in a population sub-group that is significantly exposed to mycobacteria, in an assay that is not interfered with by vaccination. Given the links between mycobacterial exposure and a range of immune system diseases, further understanding such responses may provide a new opportunity for monitoring public health and directing treatment.
Collapse
Affiliation(s)
- Alison Jones
- School of Natural Sciences, Bangor University Bangor Gwynedd LL57 2UW UK
| | - Carys A Davies
- School of Chemistry, Bangor University Bangor LL57 2UW UK
| | - Samuel Fitch
- School of Chemistry, Bangor University Bangor LL57 2UW UK
| | | | - Christopher D Gwenin
- School of Natural Sciences, Bangor University Bangor Gwynedd LL57 2UW UK
- Department of Chemistry, Xi'an Jiaotong-Liverpool University 111 Ren'ai Road, Suzhou Industrial Park Suzhou Jiangsu Province 215123 P. R. China
| | - James Gibbons
- School of Natural Sciences, Bangor University Bangor Gwynedd LL57 2UW UK
| | - A Prysor Williams
- School of Natural Sciences, Bangor University Bangor Gwynedd LL57 2UW UK
| | - Mark S Baird
- School of Chemistry, Bangor University Bangor LL57 2UW UK
| |
Collapse
|
16
|
Zhang W, Liu LL, Lun S, Wang SS, Xiao S, Gunosewoyo H, Yang F, Tang J, Bishai WR, Yu LF. Design and synthesis of mycobacterial pks13 inhibitors: Conformationally rigid tetracyclic molecules. Eur J Med Chem 2021; 213:113202. [PMID: 33516983 DOI: 10.1016/j.ejmech.2021.113202] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 11/03/2020] [Accepted: 01/12/2021] [Indexed: 10/22/2022]
Abstract
We previously reported a series of coumestans-a naturally occurring tetracyclic scaffold containing a δ-lactone-that effectively target the thioesterase domain of polyketide synthase 13 (Pks13) in Mycobacterium tuberculosis (Mtb), resulting in superior anti-tuberculosis (TB) activity. Compared to the corresponding 'open-form' ethyl benzofuran-3-carboxylates, the enhanced anti-TB effects seen with the conformationally restricted coumestan series could be attributed to the extra π-π stacking interactions between the benzene ring of coumestans and the phenyl ring of F1670 residue located in the Pks13-TE binding domain. To further probe this binding feature, novel tetracyclic analogues were synthesized and evaluated for their anti-TB activity against the Mtb strain H37Rv. Initial comparison of the 'open-form' analogueues against the tetracyclic counterparts again showed that the latter is superior in terms of anti-TB activity. In particular, the δ-lactam-containing 5H-benzofuro [3,2-c]quinolin-6-ones gave the most promising results. Compound 65 demonstrated potent activity against Mtb H37Rv with MIC value between 0.0313 and 0.0625 μg/mL, with high selectivity to Vero cells (64-128 fold). The thermal stability analysis supports the notion that the tetracyclic compounds bind to the Pks13-TE domain as measured by nano DSF, consistent with the observed SAR trends. Compound 65 also showed excellent selectivity against actinobacteria and therefore unlikely to develop potential drug resistance to nonpathogenic bacteria.
Collapse
Affiliation(s)
- Wei Zhang
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062, China
| | - Ling-Ling Liu
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062, China
| | - Shichun Lun
- Center for Tuberculosis Research, Department of Medicine, Division of Infectious Disease, Johns Hopkins School of Medicine, Baltimore, MD, 21231-1044, United States
| | - Shuang-Shuang Wang
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062, China
| | - Shiqi Xiao
- Center for Tuberculosis Research, Department of Medicine, Division of Infectious Disease, Johns Hopkins School of Medicine, Baltimore, MD, 21231-1044, United States
| | - Hendra Gunosewoyo
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley, Perth, WA, 6102, Australia
| | - Fan Yang
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062, China
| | - Jie Tang
- Shanghai Key Laboratory of Green Chemistry and Chemical Process, School of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062, China
| | - William R Bishai
- Center for Tuberculosis Research, Department of Medicine, Division of Infectious Disease, Johns Hopkins School of Medicine, Baltimore, MD, 21231-1044, United States.
| | - Li-Fang Yu
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062, China.
| |
Collapse
|
17
|
Measurement of the Intracellular Mycobacterium tuberculosis Drug Effect and Prediction of the Clinical Dose-Response Relationship Using Intracellular Pharmacodynamic Modeling (PD i). Methods Mol Biol 2021; 2296:393-408. [PMID: 33977461 DOI: 10.1007/978-1-0716-1358-0_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The human disease tuberculosis (TB) is the leading cause of death from a single infectious agent. A quarter of the world's population is estimated to be latently infected. Drug development and screening is slow and costly. We have developed a physiologically relevant assay to screen drugs against TB when inside immune cells. This chapter will describe a newly developed preclinical drug screening assay for TB, using high-content imaging and pharmacokinetic/pharmacodynamic modeling.
Collapse
|
18
|
Kumar G, Narayan R, Kapoor S. Chemical Tools for Illumination of Tuberculosis Biology, Virulence Mechanisms, and Diagnosis. J Med Chem 2020; 63:15308-15332. [PMID: 33307693 DOI: 10.1021/acs.jmedchem.0c01337] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Tuberculosis (TB) remains one of the deadliest infectious diseases and begs the scientific community to up the ante for research and exploration of completely novel therapeutic avenues. Chemical biology-inspired design of tunable chemical tools has aided in clinical diagnosis, facilitated discovery of therapeutics, and begun to enable investigation of virulence mechanisms at the host-pathogen interface of Mycobacterium tuberculosis. This Perspective highlights chemical tools specific to mycobacterial proteins and the cell lipid envelope that have furnished rapid and selective diagnostic strategies and provided unprecedented insights into the function of the mycobacterial proteome and lipidome. We discuss chemical tools that have enabled elucidating otherwise intractable biological processes by leveraging the unique lipid and metabolite repertoire of mycobacterial species. Some of these probes represent exciting starting points with the potential to illuminate poorly understood aspects of mycobacterial pathogenesis, particularly the host membrane-pathogen interactions.
Collapse
Affiliation(s)
- Gautam Kumar
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400 076, Maharashtra, India
| | - Rishikesh Narayan
- School of Chemical and Materials Sciences, Indian Institute of Technology Goa, Ponda 403 401, Goa, India
| | - Shobhna Kapoor
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400 076, Maharashtra, India.,Wadhwani Research Center for Bioengineering, Indian Institute of Technology Bombay, Mumbai 400 076, Maharashtra, India
| |
Collapse
|
19
|
Amphotericin B Inhibits Mycobacterium tuberculosis Infection of Human Alveolar Type II Epithelial A549 Cells. Antimicrob Agents Chemother 2020; 64:AAC.01164-20. [PMID: 32661004 DOI: 10.1128/aac.01164-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
20
|
Alhuwaymil ZS, Al-Araj IQM, Al Dulayymi AR, Jones A, Gates PJ, Valero-Guillén PL, Baird MS, Al Dulayymi JR. Mycobacterium alvei (ω-1)-methoxy mycolic acids: Absolute stereochemistry and synthesis. Chem Phys Lipids 2020; 233:104977. [PMID: 32961166 DOI: 10.1016/j.chemphyslip.2020.104977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/24/2020] [Accepted: 09/14/2020] [Indexed: 11/28/2022]
Abstract
Cells of Mycobacterium alvei are known to contain a unique set of mycolic acids with a (ω-1)-methoxy group; although the various enzymes in the biosynthesis of other types of mycolic acid have been widely studied, the biosynthetic route to this substituent is unclear. We now define the stereochemistry of the (ω-1)-methoxy fragment as R, and describe the synthesis of a major R-(ω-1)-methoxy-mycolic acid and its sugar esters, and of two natural M. alvei diene mycolic acids.
Collapse
Affiliation(s)
- Zamzam S Alhuwaymil
- School of Natural Sciences, Bangor University, Bangor, Gwynedd, LL57 2UW, UK
| | | | - Ahmad R Al Dulayymi
- School of Natural Sciences, Bangor University, Bangor, Gwynedd, LL57 2UW, UK
| | - Alison Jones
- School of Natural Sciences, Bangor University, Bangor, Gwynedd, LL57 2UW, UK
| | - Paul J Gates
- School of Chemistry, Bristol University, Bristol, BS8 1TS, UK
| | - Pedro L Valero-Guillén
- Departamento de Genética y Microbiología, Facultad de Medicina, Universidad de Murcia, Spain, Instituto Murciano de Investigación Biosanitaria (IMIB), Spain
| | - Mark S Baird
- School of Chemistry, Bangor University, Bangor, Gwynedd, LL57 2UW, UK
| | | |
Collapse
|
21
|
Yang X, Hu T, Yang X, Xu W, Yang H, Guddat LW, Zhang B, Rao Z. Structural Basis for the Inhibition of Mycobacterial MmpL3 by NITD-349 and SPIRO. J Mol Biol 2020; 432:4426-4434. [DOI: 10.1016/j.jmb.2020.05.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 05/13/2020] [Accepted: 05/25/2020] [Indexed: 10/24/2022]
|
22
|
Le NH, Locard-Paulet M, Stella A, Tomas N, Molle V, Burlet-Schiltz O, Daffé M, Marrakchi H. The protein kinase PknB negatively regulates biosynthesis and trafficking of mycolic acids in mycobacteria. J Lipid Res 2020; 61:1180-1191. [PMID: 32487543 DOI: 10.1194/jlr.ra120000747] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/19/2020] [Indexed: 12/13/2022] Open
Abstract
Mycobacterium tuberculosis is the causative agent of tuberculosis and remains one of the most widespread and deadliest bacterial pathogens in the world. A distinguishing feature of mycobacteria that sets them apart from other bacteria is the unique architecture of their cell wall, characterized by various species-specific lipids, most notably mycolic acids (MAs). Therefore, targeted inhibition of enzymes involved in MA biosynthesis, transport, and assembly has been extensively explored in drug discovery. Additionally, more recent evidence suggests that many enzymes in the MA biosynthesis pathway are regulated by kinase-mediated phosphorylation, thus opening additional drug-development opportunities. However, how phosphorylation regulates MA production remains unclear. Here, we used genetic strategies combined with lipidomics and phosphoproteomics approaches to investigate the role of protein phosphorylation in Mycobacterium The results of this analysis revealed that the Ser/Thr protein kinase PknB regulates the export of MAs and promotes the remodeling of the mycobacterial cell envelope. In particular, we identified the essential MmpL3 as a substrate negatively regulated by PknB. Taken together, our findings add to the understanding of how PknB activity affects the mycobacterial MA biosynthesis pathway and reveal the essential role of protein phosphorylation/dephosphorylation in governing lipid metabolism, paving the way for novel antimycobacterial strategies.
Collapse
Affiliation(s)
- Nguyen-Hung Le
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Marie Locard-Paulet
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Alexandre Stella
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Nicolas Tomas
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Virginie Molle
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université de Montpellier, CNRS, UMR 5235, Montpellier, France
| | - Odile Burlet-Schiltz
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Mamadou Daffé
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Hedia Marrakchi
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| |
Collapse
|
23
|
A re-investigation of the mycolic acids of Mycobacterium avium. Chem Phys Lipids 2020; 230:104928. [PMID: 32492381 DOI: 10.1016/j.chemphyslip.2020.104928] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 05/04/2020] [Accepted: 05/12/2020] [Indexed: 11/20/2022]
Abstract
Mycolic acid methyl esters were extracted from Mycobacterium avium by a mild saponification protocol, designed to preserve labile components. The resulting mixture of α-, keto- and wax ester mycolates was accompanied by some degraded ω-carboxymycolic acid dimethyl esters, whose overall structures were found to support previous studies. Chromatography of the mono-carboxylic mycolates gave an inseparable mixture of keto- and wax ester mycolates and separate α-mycolates. Reduction of the ketomycolate components allowed isolation and characterisation of intact wax ester mycolates for the first time. Minor α- and ω-carboxymycolates were detected in which methyl branches were located on either the proximal or distal sides of trans-alkene groups.
Collapse
|
24
|
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.
Collapse
|
25
|
Study of the conformational behaviour of trehalose mycolates by FT-IR spectroscopy. Chem Phys Lipids 2019; 223:104789. [DOI: 10.1016/j.chemphyslip.2019.104789] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 06/22/2019] [Accepted: 06/25/2019] [Indexed: 11/24/2022]
|
26
|
Liu K, Wang L, Guo Z. An extensive review of studies on mycobacterium cell wall polysaccharide-related oligosaccharides – part III: synthetic studies and biological applications of arabinofuranosyl oligosaccharides and their analogs, derivatives and conjugates. J Carbohydr Chem 2019. [DOI: 10.1080/07328303.2019.1630841] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Kechun Liu
- Biology Institute, Qilu University of Technology (Shandong Academy of Sciences), Ji′nan, Shandong, China
| | - Lizhen Wang
- Biology Institute, Qilu University of Technology (Shandong Academy of Sciences), Ji′nan, Shandong, China
| | - Zhongwu Guo
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| |
Collapse
|
27
|
Groenewald W, Parra-Cruz RA, Jäger CM, Croft AK. Revealing solvent-dependent folding behavior of mycolic acids from Mycobacterium tuberculosis by advanced simulation analysis. J Mol Model 2019; 25:68. [PMID: 30762132 PMCID: PMC7019640 DOI: 10.1007/s00894-019-3943-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 01/24/2019] [Indexed: 11/09/2022]
Abstract
Mycobacterium tuberculosis remains a persistent pathogen, partly due to its lipid rich cell wall, of which mycolic acids (MAs) are a major component. The fluidity and conformational flexibilities of different MAs in the bacterial cell wall significantly influence its properties, function, and observed pathogenicity; thus, a proper conformational description of different MAs in different environments (e.g., in vacuum, in solution, in monolayers) can inform about their potential role in the complex setup of the bacterial cell wall. Previously, we have shown that molecular dynamics (MD) simulations of MA folding in vacuo can be used to characterize MA conformers in seven groupings relating to bending at the functional groups (W, U and Z-conformations). Providing a new OPLS-based forcefield parameterization for the critical cyclopropyl group of MAs and extensive simulations in explicit solvents (TIP4P water, hexane), we now present a more complete picture of MA folding properties together with improved simulation analysis techniques. We show that the 'WUZ' distance-based analysis can be used to pinpoint conformers with hairpin bends at the functional groups, with these conformers constituting only a fraction of accessible conformations. Applying principle component analysis (PCA) and refinement using free energy landscapes (FELs), we are able to discriminate a complete and unique set of conformational preferences for representative alpha-, methoxy- and keto-MAs, with overall preference for folded conformations. A control backbone-MA without any mero-chain functional groups showed significantly less folding in the mero-chain, confirming the role of functionalization in directing folding. Keto-MA showed the highest percentage of WUZ-type conformations and, in particular, a tendency to fold at its alpha-methyl trans-cyclopropane group, in agreement with results from Villeneuve et al. MAs demonstrate similar folding in vacuum and water, with a majority of folded conformations around the W-conformation, although the molecules are more flexible in vacuum than in water. Exchange between conformations, with a disperse distribution that includes unfolded conformers, is common in hexane for all MAs, although with more organization for Keto-MA. Globular, folded conformations are newly defined and may be specifically relevant in biofilms. Graphical abstract Through advanced simulation analysis, including principle component analysis and free energy landscapes, we reveal detailed physical insights into the solvent-dependant folding behavior of mycolic acids from M. tb.
Collapse
Affiliation(s)
- Wilma Groenewald
- School of Chemistry, Bangor University, Bangor, Gwynedd, LL57 2UW, UK
| | - Ricardo A Parra-Cruz
- Department of Chemical and Environmental Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Christof M Jäger
- Department of Chemical and Environmental Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Anna K Croft
- Department of Chemical and Environmental Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD, UK.
| |
Collapse
|
28
|
Villeneuve M, Noguchi H. Roles of α-methyl trans-cyclopropane groups in behavior of mixed mycolic acid monolayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:441-448. [DOI: 10.1016/j.bbamem.2018.10.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 09/15/2018] [Accepted: 10/16/2018] [Indexed: 01/01/2023]
|
29
|
AlMatar M, Makky EA, AlMandeal H, Eker E, Kayar B, Var I, Köksal F. Does the Development of Vaccines Advance Solutions for Tuberculosis? Curr Mol Pharmacol 2018; 12:83-104. [PMID: 30474542 DOI: 10.2174/1874467212666181126151948] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 10/06/2018] [Accepted: 10/17/2018] [Indexed: 11/22/2022]
Abstract
BACKGROUND Mycobacterium tuberculosis (Mtb) is considered as one of the most efficacious human pathogens. The global mortality rate of TB stands at approximately 2 million, while about 8 to 10 million active new cases are documented yearly. It is, therefore, a priority to develop vaccines that will prevent active TB. The vaccines currently used for the management of TB can only proffer a certain level of protection against meningitis, TB, and other forms of disseminated TB in children; however, their effectiveness against pulmonary TB varies and cannot provide life-long protective immunity. Based on these reasons, more efforts are channeled towards the development of new TB vaccines. During the development of TB vaccines, a major challenge has always been the lack of diversity in both the antigens contained in TB vaccines and the immune responses of the TB sufferers. Current efforts are channeled on widening both the range of antigens selection and the range of immune response elicited by the vaccines. The past two decades witnessed a significant progress in the development of TB vaccines; some of the discovered TB vaccines have recently even completed the third phase (phase III) of a clinical trial. OBJECTIVE The objectives of this article are to discuss the recent progress in the development of new vaccines against TB; to provide an insight on the mechanism of vaccine-mediated specific immune response stimulation, and to debate on the interaction between vaccines and global interventions to end TB.
Collapse
Affiliation(s)
- Manaf AlMatar
- Department of Biotechnology, Institute of Natural and Applied Sciences (Fen Bilimleri Enstitusu) Cukurova University, Adana, Turkey
| | - Essam A Makky
- Department of Biotechnology, Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang (UMP), Kuantan, Malaysia
| | - Husam AlMandeal
- Freiburg Universität, Moltkestraße 90, 76133 karlsruhe Augenklinik, Germany
| | - Emel Eker
- Department of Medical Microbiology, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Begüm Kayar
- Department of Medical Microbiology, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Işıl Var
- Department of Food Engineering, Agricultural Faculty, Cukurova University, Adana, Turkey
| | - Fatih Köksal
- Department of Medical Microbiology, Faculty of Medicine, Cukurova University, Adana, Turkey
| |
Collapse
|
30
|
Man DKW, Kanno T, Manzo G, Robertson BD, Lam JKW, Mason AJ. Rifampin- or Capreomycin-Induced Remodeling of the Mycobacterium smegmatis Mycolic Acid Layer Is Mitigated in Synergistic Combinations with Cationic Antimicrobial Peptides. mSphere 2018; 3:e00218-18. [PMID: 30021876 PMCID: PMC6052339 DOI: 10.1128/msphere.00218-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 06/24/2018] [Indexed: 01/15/2023] Open
Abstract
The mycobacterial cell wall affords natural resistance to antibiotics. Antimicrobial peptides (AMPs) modify the surface properties of mycobacteria and can act synergistically with antibiotics from differing classes. Here, we investigate the response of Mycobacterium smegmatis to the presence of rifampin or capreomycin, either alone or in combination with two synthetic, cationic, α-helical AMPs that are distinguished by the presence (D-LAK120-HP13) or absence (D-LAK120-A) of a kink-inducing proline. Using a combination of high-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) metabolomics, diphenylhexatriene (DPH) fluorescence anisotropy measurements, and laurdan emission spectroscopy, we show that M. smegmatis responds to challenge with rifampin or capreomycin by substantially altering its metabolism and, in particular, by remodeling the cell envelope. Overall, the changes are consistent with a reduction of trehalose dimycolate and an increase of trehalose monomycolate and are associated with increased rigidity of the mycolic acid layer observed following challenge by capreomycin but not rifampin. Challenge with D-LAK120-A or D-LAK120-HP13 induced no or modest changes, respectively, in mycomembrane metabolites and did not induce a significant increase in the rigidity of the mycolic acid layer. Furthermore, the response to rifampin or capreomycin was significantly reduced when these were combined with D-LAK120-HP13 and D-LAK120-A, respectively, suggesting a possible mechanism for the synergy of these combinations. The remodeling of the mycomembrane in M. smegmatis is therefore identified as an important countermeasure deployed against rifampin or capreomycin, but this can be mitigated and the efficacy of rifampin or capreomycin potentiated by combining the drug with AMPs.IMPORTANCE We have used a combined NMR metabolomics/biophysical approach to better understand differences in the mechanisms of two closely related antimicrobial peptides, as well as the response of the model organism Mycobacterium smegmatis to challenge with first- or second-line antibiotics used against mycobacterial pathogens. We show that, in addition to membrane damage, the triggering of oxidative stress may be an important part of the mechanism of action of one AMP. The metabolic shift that accompanied rifampin and, particularly, capreomycin challenge was associated with modest and more dramatic changes, respectively, in the mycomembrane, providing a rationale for how the response to one antibiotic may affect bacterial penetration and, hence, the action of another. This study presents the first insights into how antimicrobial peptides may operate synergistically with existing antibiotics whose efficacy is waning or sensitize MDR mycobacteria and/or latent mycobacterial infections to them, prolonging the useful life of these drugs.
Collapse
Affiliation(s)
- DeDe Kwun-Wai Man
- Institute of Pharmaceutical Sciences, School of Cancer & Pharmaceutical Sciences, King's College London, London, United Kingdom
- Department of Pharmacology & Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Tokuwa Kanno
- Institute of Pharmaceutical Sciences, School of Cancer & Pharmaceutical Sciences, King's College London, London, United Kingdom
| | - Giorgia Manzo
- Institute of Pharmaceutical Sciences, School of Cancer & Pharmaceutical Sciences, King's College London, London, United Kingdom
| | - Brian D Robertson
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, United Kingdom
| | - Jenny K W Lam
- Department of Pharmacology & Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - A James Mason
- Institute of Pharmaceutical Sciences, School of Cancer & Pharmaceutical Sciences, King's College London, London, United Kingdom
| |
Collapse
|
31
|
Bird JH, Khan AA, Nishimura N, Yamasaki S, Timmer MSM, Stocker BL. Synthesis of Branched Trehalose Glycolipids and Their Mincle Agonist Activity. J Org Chem 2018; 83:7593-7605. [DOI: 10.1021/acs.joc.7b03269] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jessie H. Bird
- School of Chemical and Physical Sciences, Victoria University of Wellington, PO Box 600, Wellington, New Zealand
| | - Ashna A. Khan
- School of Chemical and Physical Sciences, Victoria University of Wellington, PO Box 600, Wellington, New Zealand
| | - Naoya Nishimura
- Division of Molecular Immunology, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita 565-0871, Japan
| | - Sho Yamasaki
- Division of Molecular Immunology, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita 565-0871, Japan
| | - Mattie S. M. Timmer
- School of Chemical and Physical Sciences, Victoria University of Wellington, PO Box 600, Wellington, New Zealand
| | - Bridget L. Stocker
- School of Chemical and Physical Sciences, Victoria University of Wellington, PO Box 600, Wellington, New Zealand
| |
Collapse
|
32
|
Lefebvre C, Boulon R, Ducoux M, Gavalda S, Laval F, Jamet S, Eynard N, Lemassu A, Cam K, Bousquet MP, Bardou F, Burlet-Schiltz O, Daffé M, Quémard A. HadD, a novel fatty acid synthase type II protein, is essential for alpha- and epoxy-mycolic acid biosynthesis and mycobacterial fitness. Sci Rep 2018; 8:6034. [PMID: 29662082 PMCID: PMC5902629 DOI: 10.1038/s41598-018-24380-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 04/03/2018] [Indexed: 02/05/2023] Open
Abstract
Mycolic acids (MAs) have a strategic location within the mycobacterial envelope, deeply influencing its architecture and permeability, and play a determinant role in the pathogenicity of mycobacteria. The fatty acid synthase type II (FAS-II) multienzyme system is involved in their biosynthesis. A combination of pull-downs and proteomics analyses led to the discovery of a mycobacterial protein, HadD, displaying highly specific interactions with the dehydratase HadAB of FAS-II. In vitro activity assays and homology modeling showed that HadD is, like HadAB, a hot dog folded (R)-specific hydratase/dehydratase. A hadD knockout mutant of Mycobacterium smegmatis produced only the medium-size alpha’-MAs. Data strongly suggest that HadD is involved in building the third meromycolic segment during the late FAS-II elongation cycles, leading to the synthesis of the full-size alpha- and epoxy-MAs. The change in the envelope composition induced by hadD inactivation strongly altered the bacterial fitness and capacities to aggregate, assemble into colonies or biofilms and spread by sliding motility, and conferred a hypersensitivity to the firstline antimycobacterial drug rifampicin. This showed that the cell surface properties and the envelope integrity were greatly affected. With the alarmingly increasing case number of nontuberculous mycobacterial diseases, HadD appears as an attractive target for drug development.
Collapse
Affiliation(s)
- Cyril Lefebvre
- Département Tuberculose & Biologie des Infections, Institut de Pharmacologie et de Biologie Structurale, UMR5089, Université de Toulouse, CNRS, UPS, 31077, Toulouse Cedex 04, France
| | - Richard Boulon
- Département Tuberculose & Biologie des Infections, Institut de Pharmacologie et de Biologie Structurale, UMR5089, Université de Toulouse, CNRS, UPS, 31077, Toulouse Cedex 04, France
| | - Manuelle Ducoux
- Département Biologie Structurale & Biophysique, Institut de Pharmacologie et de Biologie Structurale, UMR5089, Université de Toulouse, CNRS, UPS, 31077, Toulouse Cedex 04, France
| | - Sabine Gavalda
- Département Tuberculose & Biologie des Infections, Institut de Pharmacologie et de Biologie Structurale, UMR5089, Université de Toulouse, CNRS, UPS, 31077, Toulouse Cedex 04, France
| | - Françoise Laval
- Département Tuberculose & Biologie des Infections, Institut de Pharmacologie et de Biologie Structurale, UMR5089, Université de Toulouse, CNRS, UPS, 31077, Toulouse Cedex 04, France
| | - Stevie Jamet
- Département Tuberculose & Biologie des Infections, Institut de Pharmacologie et de Biologie Structurale, UMR5089, Université de Toulouse, CNRS, UPS, 31077, Toulouse Cedex 04, France
| | - Nathalie Eynard
- Département Tuberculose & Biologie des Infections, Institut de Pharmacologie et de Biologie Structurale, UMR5089, Université de Toulouse, CNRS, UPS, 31077, Toulouse Cedex 04, France
| | - Anne Lemassu
- Département Tuberculose & Biologie des Infections, Institut de Pharmacologie et de Biologie Structurale, UMR5089, Université de Toulouse, CNRS, UPS, 31077, Toulouse Cedex 04, France
| | - Kaymeuang Cam
- Département Tuberculose & Biologie des Infections, Institut de Pharmacologie et de Biologie Structurale, UMR5089, Université de Toulouse, CNRS, UPS, 31077, Toulouse Cedex 04, France
| | - Marie-Pierre Bousquet
- Département Biologie Structurale & Biophysique, Institut de Pharmacologie et de Biologie Structurale, UMR5089, Université de Toulouse, CNRS, UPS, 31077, Toulouse Cedex 04, France
| | - Fabienne Bardou
- Département Tuberculose & Biologie des Infections, Institut de Pharmacologie et de Biologie Structurale, UMR5089, Université de Toulouse, CNRS, UPS, 31077, Toulouse Cedex 04, France
| | - Odile Burlet-Schiltz
- Département Biologie Structurale & Biophysique, Institut de Pharmacologie et de Biologie Structurale, UMR5089, Université de Toulouse, CNRS, UPS, 31077, Toulouse Cedex 04, France
| | - Mamadou Daffé
- Département Tuberculose & Biologie des Infections, Institut de Pharmacologie et de Biologie Structurale, UMR5089, Université de Toulouse, CNRS, UPS, 31077, Toulouse Cedex 04, France
| | - Annaïk Quémard
- Département Tuberculose & Biologie des Infections, Institut de Pharmacologie et de Biologie Structurale, UMR5089, Université de Toulouse, CNRS, UPS, 31077, Toulouse Cedex 04, France.
| |
Collapse
|
33
|
Chancellor A, Tocheva AS, Cave-Ayland C, Tezera L, White A, Al Dulayymi JR, Bridgeman JS, Tews I, Wilson S, Lissin NM, Tebruegge M, Marshall B, Sharpe S, Elliott T, Skylaris CK, Essex JW, Baird MS, Gadola S, Elkington P, Mansour S. CD1b-restricted GEM T cell responses are modulated by Mycobacterium tuberculosis mycolic acid meromycolate chains. Proc Natl Acad Sci U S A 2017; 114:E10956-E10964. [PMID: 29158404 PMCID: PMC5754766 DOI: 10.1073/pnas.1708252114] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Tuberculosis (TB), caused by Mycobacterium tuberculosis, remains a major human pandemic. Germline-encoded mycolyl lipid-reactive (GEM) T cells are donor-unrestricted and recognize CD1b-presented mycobacterial mycolates. However, the molecular requirements governing mycolate antigenicity for the GEM T cell receptor (TCR) remain poorly understood. Here, we demonstrate CD1b expression in TB granulomas and reveal a central role for meromycolate chains in influencing GEM-TCR activity. Meromycolate fine structure influences T cell responses in TB-exposed individuals, and meromycolate alterations modulate functional responses by GEM-TCRs. Computational simulations suggest that meromycolate chain dynamics regulate mycolate head group movement, thereby modulating GEM-TCR activity. Our findings have significant implications for the design of future vaccines that target GEM T cells.
Collapse
Affiliation(s)
- Andrew Chancellor
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
- Public Health England, National Infections Service, Porton Down, Salisbury SP4 0JQ, United Kingdom
| | - Anna S Tocheva
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
| | - Chris Cave-Ayland
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Liku Tezera
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
| | - Andrew White
- Public Health England, National Infections Service, Porton Down, Salisbury SP4 0JQ, United Kingdom
| | - Juma'a R Al Dulayymi
- School of Chemistry, Bangor University, Bangor, Gwynedd LL57 2UW, United Kingdom
| | | | - Ivo Tews
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Susan Wilson
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
- Histochemistry Unit, University of Southampton, Southampton SO16 6YD, United Kingdom
| | | | - Marc Tebruegge
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
- NIHR Southampton Biomedical Research Centre, Southampton SO17 1BJ, United Kingdom
- Global Health Research Institute, University of Southampton, Southampton SO17 1BJ, United Kingdom
- Department of Paediatrics, Faculty of Medicine, University of Melbourne, 3052 Parkville, Australia
- Department of Paediatric Infectious Diseases & Immunology, Evelina London Children's Hospital, Guy's and St. Thomas' NHS Foundation Trust, London SE1 7EH, United Kingdom
| | - Ben Marshall
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
- NIHR Southampton Biomedical Research Centre, Southampton SO17 1BJ, United Kingdom
| | - Sally Sharpe
- Public Health England, National Infections Service, Porton Down, Salisbury SP4 0JQ, United Kingdom
| | - Tim Elliott
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
- Cancer Sciences Unit, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
| | - Chris-Kriton Skylaris
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Jonathan W Essex
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Mark S Baird
- School of Chemistry, Bangor University, Bangor, Gwynedd LL57 2UW, United Kingdom
| | - Stephan Gadola
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
- F. Hoffmann-La Roche Ltd., 4070 Basel, Switzerland
| | - Paul Elkington
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
- NIHR Southampton Biomedical Research Centre, Southampton SO17 1BJ, United Kingdom
- Global Health Research Institute, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Salah Mansour
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom;
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| |
Collapse
|
34
|
Chen W, Liu Y, Zhang L, Gu X, Liu G, Shahid M, Gao J, Ali T, Han B. Nocardia cyriacigeogica from Bovine Mastitis Induced In vitro Apoptosis of Bovine Mammary Epithelial Cells via Activation of Mitochondrial-Caspase Pathway. Front Cell Infect Microbiol 2017; 7:194. [PMID: 28573110 PMCID: PMC5435817 DOI: 10.3389/fcimb.2017.00194] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 05/03/2017] [Indexed: 11/13/2022] Open
Abstract
Nocardia is one of the causing agents of bovine mastitis and increasing prevalence of nocardial mastitis in shape of serious outbreaks has been reported from many countries. However, the mechanisms by which this pathogen damages the bovine mammary epithelial cells (bMECs) is not yet studied. Therefore, this study was designed with the aim to evaluate the apoptotic effects elicited by Nocardia and to investigate the pathway by which the Nocardia induce apoptosis in bMECs. Clinical Nocardia cyriacigeorgica strain from bovine mastitis was used to infect the bMECs for different time intervals, viz. 1, 3, 6, 12, and 18 h, and then the induced effects on bMECs were studied using adhesion and invasion assays, release of lactate dehydrogenase (LDH), apoptosis analysis by annexin V and propidium iodide (PI) double staining, morphological, and ultrastructural observations under scanning electron microscope (SEM) and transmission electron microscope (TEM), mitochondrial transmembrane potential (ΔΨm) assay using flow cytometry, and the protein quantification of mitochondrial cytochrome c and caspase-9 and caspase-3 by western blotting. The results of this study showed that N. cyriacigeorgica possessed the abilities of adhesion and invasion to bMECs. N. cyriacigeorgica was found to collapse mitochondrial transmembrane potential, significantly (p < 0.05) release mitochondrial cytochrome c and ultimately induce cell apoptosis. Additionally, it promoted casepase-9 (p < 0.01) and casepase-3 (p < 0.05) levels, significantly (p < 0.01) increased the release of LDH and promoted DNA fragmentation which further confirmed the apoptosis. Furthermore, N. cyriacigeorgica induced apoptosis/necrosis manifested specific ultrastructure features under TEM, such as swollen endoplasmic reticulum, cristae degeneration, and swelling of mitochondria, vesicle formation on the cell surface, rupturing of cell membrane and nuclear membrane, clumping, fragmentation, and margination of chromatin. The present study is the first comprehensive insight into patho-morphological ultrastructural features of apoptosis/necrosis induced by N. cyriacigeorgica, which concluded that the clinical N. cyriacigeorgica induced apoptotic changes in the bMECs through mitochondrial-caspase dependent apoptotic pathway.
Collapse
Affiliation(s)
- Wei Chen
- Department of Veterinary Clinics, College of Veterinary Medicine, China Agricultural UniversityBeijing, China
| | - Yongxia Liu
- Department of Veterinary Clinics, College of Veterinary Medicine, Shandong Agricultural UniversityTai'an, China
| | - Limei Zhang
- Department of Veterinary Clinics, College of Veterinary Medicine, China Agricultural UniversityBeijing, China
| | - Xiaolong Gu
- Department of Veterinary Clinics, College of Veterinary Medicine, China Agricultural UniversityBeijing, China
| | - Gang Liu
- Department of Veterinary Clinics, College of Veterinary Medicine, China Agricultural UniversityBeijing, China
| | - Muhammad Shahid
- Department of Veterinary Clinics, College of Veterinary Medicine, China Agricultural UniversityBeijing, China
| | - Jian Gao
- Department of Veterinary Clinics, College of Veterinary Medicine, China Agricultural UniversityBeijing, China
| | - Tariq Ali
- Department of Veterinary Clinics, College of Veterinary Medicine, China Agricultural UniversityBeijing, China
| | - Bo Han
- Department of Veterinary Clinics, College of Veterinary Medicine, China Agricultural UniversityBeijing, China
| |
Collapse
|
35
|
Abstract
R- and S-Glycerol mycolates derived from single synthetic α-, keto- and methoxy-mycolic acids are described.
Collapse
Affiliation(s)
- Omar T Ali
- School of Chemistry, Bangor University, Bangor, Gwynedd, Wales, LL57 2UW, UK
| | - Mohaned M Sahb
- School of Chemistry, Bangor University, Bangor, Gwynedd, Wales, LL57 2UW, UK
| | | | - Mark S Baird
- School of Chemistry, Bangor University, Bangor, Gwynedd, Wales, LL57 2UW, UK.
| |
Collapse
|
36
|
Das I, Padhi A, Mukherjee S, Dash DP, Kar S, Sonawane A. Biocompatible chitosan nanoparticles as an efficient delivery vehicle for Mycobacterium tuberculosis lipids to induce potent cytokines and antibody response through activation of γδ T cells in mice. NANOTECHNOLOGY 2017; 28:165101. [PMID: 28206982 DOI: 10.1088/1361-6528/aa60fd] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The activation of cell-mediated and humoral immune responses to Mycobacterium tuberculosis (Mtb) is critical for protection against the pathogen and nanoparticle-mediated delivery of antigens is a more potent way to induce different immune responses. Herein, we show that mice immunized with Mtb lipid-bound chitosan nanoparticles (NPs) induce secretion of prominent type-1 T-helper (Th-1) and type-2 T-helper (Th-2) cytokines in lymph node and spleen cells, and also induces significantly higher levels of IgG, IgG1, IgG2 and IgM in comparison to control mice. Furthermore, significantly enhanced γδ-T-cell activation was observed in lymph node cells isolated from mice immunized with Mtb lipid-coated chitosan NPs as compared to mice immunized with chitosan NPs alone or Mtb lipid liposomes. In comparison to CD8+ cells, significantly higher numbers of CD4+ cells were present in both the lymph node and spleen cells isolated from mice immunized with Mtb lipid-coated chitosan NPs. In conclusion, this study represents a promising new strategy for the efficient delivery of Mtb lipids using chitosan NPs to trigger an enhanced cell-mediated and antibody response against Mtb lipids.
Collapse
Affiliation(s)
- Ishani Das
- School of Biotechnology, KIIT University, Bhubaneswar, Odisha, India
| | | | | | | | | | | |
Collapse
|
37
|
Vermeulen I, Baird M, Al-Dulayymi J, Smet M, Verschoor J, Grooten J. Mycolates of Mycobacterium tuberculosis modulate the flow of cholesterol for bacillary proliferation in murine macrophages. J Lipid Res 2017; 58:709-718. [PMID: 28193630 DOI: 10.1194/jlr.m073171] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 01/28/2017] [Indexed: 12/11/2022] Open
Abstract
The differentiation of macrophages into lipid-filled foam cells is a hallmark of the lung granuloma that forms in patients with active tuberculosis (TB). Mycolic acids (MAs), the abundant lipid virulence factors in the cell wall of Mycobacterium tuberculosis (Mtb), can induce this foam phenotype possibly as a way to perturb host cell lipid homeostasis to support the infection. It is not exactly clear how MAs allow differentiation of foam cells during Mtb infection. Here we investigated how chemically synthetic MAs, each with a defined stereochemistry similar to natural Mtb-associated mycolates, influence cell foamy phenotype and mycobacterial proliferation in murine host macrophages. Using light and laser-scanning-confocal microscopy, we assessed the influence of MA structure first on the induction of granuloma cell types, second on intracellular cholesterol accumulation, and finally on mycobacterial growth. While methoxy-MAs (mMAs) effected multi-vacuolar giant cell formation, keto-MAs (kMAs) induced abundant intracellular lipid droplets that were packed with esterified cholesterol. Macrophages from mice treated with kMA were permissive to mycobacterial growth, whereas cells from mMA treatment were not. This suggests a separate yet key involvement of oxygenated MAs in manipulating host cell lipid homeostasis to establish the state of TB.
Collapse
Affiliation(s)
- Ilke Vermeulen
- Laboratory of Molecular Immunology, Department of Biomedical Molecular Biology, Ghent University, Ghent Zwijnaarde 9052, Belgium; Department of Biochemistry, University of Pretoria, Pretoria 0002, South Africa
| | - Mark Baird
- School of Chemistry, Bangor University, Bangor LL57 2UW, United Kingdom
| | - Juma Al-Dulayymi
- School of Chemistry, Bangor University, Bangor LL57 2UW, United Kingdom
| | - Muriel Smet
- Laboratory of Molecular Immunology, Department of Biomedical Molecular Biology, Ghent University, Ghent Zwijnaarde 9052, Belgium
| | - Jan Verschoor
- Department of Biochemistry, University of Pretoria, Pretoria 0002, South Africa
| | - Johan Grooten
- Laboratory of Molecular Immunology, Department of Biomedical Molecular Biology, Ghent University, Ghent Zwijnaarde 9052, Belgium.
| |
Collapse
|
38
|
Nunes-Costa D, Maranha A, Costa M, Alarico S, Empadinhas N. Glucosylglycerate metabolism, bioversatility and mycobacterial survival. Glycobiology 2016; 27:213-227. [DOI: 10.1093/glycob/cww132] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 12/14/2016] [Indexed: 12/17/2022] Open
|
39
|
Fineran P, Lloyd-Evans E, Lack NA, Platt N, Davis LC, Morgan AJ, Höglinger D, Tatituri RVV, Clark S, Williams IM, Tynan P, Al Eisa N, Nazarova E, Williams A, Galione A, Ory DS, Besra GS, Russell DG, Brenner MB, Sim E, Platt FM. Pathogenic mycobacteria achieve cellular persistence by inhibiting the Niemann-Pick Type C disease cellular pathway. Wellcome Open Res 2016. [PMID: 28008422 DOI: 10.12688/wellcomeopenres.10036.1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Tuberculosis remains a major global health concern. The ability to prevent phagosome-lysosome fusion is a key mechanism by which intracellular mycobacteria, including Mycobacterium tuberculosis, achieve long-term persistence within host cells. The mechanisms underpinning this key intracellular pro-survival strategy remain incompletely understood. Host macrophages infected with persistent mycobacteria share phenotypic similarities with cells taken from patients suffering from Niemann-Pick Disease Type C (NPC), a rare lysosomal storage disease in which endocytic trafficking defects and lipid accumulation within the lysosome lead to cell dysfunction and cell death. We investigated whether these shared phenotypes reflected an underlying mechanistic connection between mycobacterial intracellular persistence and the host cell pathway dysfunctional in NPC. METHODS The induction of NPC phenotypes in macrophages from wild-type mice or obtained from healthy human donors was assessed via infection with mycobacteria and subsequent measurement of lipid levels and intracellular calcium homeostasis. The effect of NPC therapeutics on intracellular mycobacterial load was also assessed. RESULTS Macrophages infected with persistent intracellular mycobacteria phenocopied NPC cells, exhibiting accumulation of multiple lipid types, reduced lysosomal Ca2+ levels, and defects in intracellular trafficking. These NPC phenotypes could also be induced using only lipids/glycomycolates from the mycobacterial cell wall. These data suggest that persistent intracellular mycobacteria inhibit the NPC pathway, likely via inhibition of the NPC1 protein, and subsequently induce altered acidic store Ca2+ homeostasis. Reduced lysosomal calcium levels may provide a mechanistic explanation for the reduced levels of phagosome-lysosome fusion in mycobacterial infection. Treatments capable of correcting defects in NPC mutant cells via modulation of host cell calcium were of benefit in promoting clearance of mycobacteria from infected host cells. CONCLUSION These findings provide a novel mechanistic explanation for mycobacterial intracellular persistence, and suggest that targeting interactions between the mycobacteria and host cell pathways may provide a novel avenue for development of anti-TB therapies.
Collapse
Affiliation(s)
- Paul Fineran
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Emyr Lloyd-Evans
- Department of Pharmacology, University of Oxford, Oxford, UK.,School of Biosciences, Cardiff University, Cardiff, UK
| | - Nathan A Lack
- Department of Pharmacology, University of Oxford, Oxford, UK.,School of Medicine, Koç University, Istanbul, Turkey
| | - Nick Platt
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Lianne C Davis
- Department of Pharmacology, University of Oxford, Oxford, UK
| | | | - Doris Höglinger
- Department of Pharmacology, University of Oxford, Oxford, UK
| | | | | | - Ian M Williams
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Patricia Tynan
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Nada Al Eisa
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Evgeniya Nazarova
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, USA
| | | | - Antony Galione
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Daniel S Ory
- Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, USA
| | - Gurdyal S Besra
- School of Biosciences, University of Birmingham, Birmingham, UK
| | - David G Russell
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, USA
| | - Michael B Brenner
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, USA
| | - Edith Sim
- Department of Pharmacology, University of Oxford, Oxford, UK.,Faculty of Science Engineering and Computing, Kingston University, Kingston upon Thames, UK
| | - Frances M Platt
- Department of Pharmacology, University of Oxford, Oxford, UK
| |
Collapse
|
40
|
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.
Collapse
Affiliation(s)
- Hermann Giresse Tima
- Scientific Service Immunology, O.D. Communicable and Infectious Diseases, Scientific Institute of Public Health (WIV-ISP), Brussels, Belgium
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Fineran P, Lloyd-Evans E, Lack NA, Platt N, Davis LC, Morgan AJ, Höglinger D, Tatituri RVV, Clark S, Williams IM, Tynan P, Al Eisa N, Nazarova E, Williams A, Galione A, Ory DS, Besra GS, Russell DG, Brenner MB, Sim E, Platt FM. Pathogenic mycobacteria achieve cellular persistence by inhibiting the Niemann-Pick Type C disease cellular pathway. Wellcome Open Res 2016; 1:18. [PMID: 28008422 PMCID: PMC5172425 DOI: 10.12688/wellcomeopenres.10036.2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/14/2017] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Tuberculosis remains a major global health concern. The ability to prevent phagosome-lysosome fusion is a key mechanism by which intracellular mycobacteria, including Mycobacterium tuberculosis, achieve long-term persistence within host cells. The mechanisms underpinning this key intracellular pro-survival strategy remain incompletely understood. Host macrophages infected with persistent mycobacteria share phenotypic similarities with cells taken from patients suffering from Niemann-Pick Disease Type C (NPC), a rare lysosomal storage disease in which endocytic trafficking defects and lipid accumulation within the lysosome lead to cell dysfunction and cell death. We investigated whether these shared phenotypes reflected an underlying mechanistic connection between mycobacterial intracellular persistence and the host cell pathway dysfunctional in NPC. METHODS The induction of NPC phenotypes in macrophages from wild-type mice or obtained from healthy human donors was assessed via infection with mycobacteria and subsequent measurement of lipid levels and intracellular calcium homeostasis. The effect of NPC therapeutics on intracellular mycobacterial load was also assessed. RESULTS Macrophages infected with persistent intracellular mycobacteria phenocopied NPC cells, exhibiting accumulation of multiple lipid types, reduced lysosomal Ca2+ levels, and defects in intracellular trafficking. These NPC phenotypes could also be induced using only lipids/glycomycolates from the mycobacterial cell wall. These data suggest that persistent intracellular mycobacteria inhibit the NPC pathway, likely via inhibition of the NPC1 protein, and subsequently induce altered acidic store Ca2+ homeostasis. Reduced lysosomal calcium levels may provide a mechanistic explanation for the reduced levels of phagosome-lysosome fusion in mycobacterial infection. Treatments capable of correcting defects in NPC mutant cells via modulation of host cell calcium were of benefit in promoting clearance of mycobacteria from infected host cells. CONCLUSION These findings provide a novel mechanistic explanation for mycobacterial intracellular persistence, and suggest that targeting interactions between the mycobacteria and host cell pathways may provide a novel avenue for development of anti-TB therapies.
Collapse
Affiliation(s)
- Paul Fineran
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Emyr Lloyd-Evans
- Department of Pharmacology, University of Oxford, Oxford, UK
- School of Biosciences, Cardiff University, Cardiff, UK
| | - Nathan A. Lack
- Department of Pharmacology, University of Oxford, Oxford, UK
- School of Medicine, Koç University, Istanbul, Turkey
| | - Nick Platt
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Lianne C. Davis
- Department of Pharmacology, University of Oxford, Oxford, UK
| | | | - Doris Höglinger
- Department of Pharmacology, University of Oxford, Oxford, UK
| | | | | | - Ian M. Williams
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Patricia Tynan
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Nada Al Eisa
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Evgeniya Nazarova
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, USA
| | | | - Antony Galione
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Daniel S. Ory
- Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, USA
| | | | - David G. Russell
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, USA
| | - Michael B. Brenner
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, USA
| | - Edith Sim
- Department of Pharmacology, University of Oxford, Oxford, UK
- Faculty of Science Engineering and Computing, Kingston University, Kingston upon Thames, UK
| | | |
Collapse
|
42
|
Ali HM, Koza G, Hameed RT, Rowles R, Davies C, Al Dulayymi JR, Gwenin CD, Baird MS. The synthesis of single enantiomers of trans-alkene containing mycolic acids and related sugar esters. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.08.089] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
43
|
Quémard A. New Insights into the Mycolate-Containing Compound Biosynthesis and Transport in Mycobacteria. Trends Microbiol 2016; 24:725-738. [DOI: 10.1016/j.tim.2016.04.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 04/14/2016] [Accepted: 04/29/2016] [Indexed: 12/15/2022]
|
44
|
Smet M, Pollard C, De Beuckelaer A, Van Hoecke L, Vander Beken S, De Koker S, Al Dulayymi JR, Huygen K, Verschoor J, Baird MS, Grooten J. Mycobacterium tuberculosis-associated synthetic mycolates differentially exert immune stimulatory adjuvant activity. Eur J Immunol 2016; 46:2149-54. [PMID: 27349218 DOI: 10.1002/eji.201646357] [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] [Received: 02/14/2016] [Revised: 05/14/2016] [Accepted: 06/23/2016] [Indexed: 12/12/2022]
Abstract
Mycolic acids (MAs) are highly hydrophobic long-chain α-alkyl β-hydroxy fatty acids present in the cell wall of Mycobacterium tuberculosis (Mtb) as a complex mixture of molecules with a common general structure but with variable functional groups in the meromycolate chain. In this study, we addressed the relationship between the MA molecular structure and their contribution to the development of T-cell immune responses. Hereto, we used the model antigen ovalbumin and single synthetic MAs, differing in oxygenation class and cis versus trans proximal cyclopropane configuration, as immune stimulatory agents. Subcutaneous delivery of liposome-formulated MAs with a proximal cis cyclopropane elicited antigen-specific Th1 and cytotoxic T-cell immune responses, whereas intratracheal immunization elicited pulmonary Th17 responses. These immune stimulatory activities depended not only on the cis versus trans proximal cyclopropane configuration but also on the MA oxygenation class. Our study thus shows that both the presence and nature of the functional groups in the meromycolate chain affect the immune stimulatory adjuvant activity of Mtb mycolates and suggests that Mtb bacilli may impact on the host protective immune response by modulating the cis versus trans stereochemistry of its mycolates as well as by altering the oxygenation class of the meromycolate functional group.
Collapse
Affiliation(s)
- Muriel Smet
- Laboratory of Molecular Immunology, Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Charlotte Pollard
- Laboratory of Molecular Immunology, Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Ans De Beuckelaer
- Laboratory of Molecular Immunology, Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Lien Van Hoecke
- Laboratory of Molecular Immunology, Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,Medical Biotechnology Center, Flanders Institute for Biotechnology, Ghent, Belgium
| | - Seppe Vander Beken
- Laboratory of Molecular Immunology, Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Stefaan De Koker
- Laboratory of Molecular Immunology, Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | | | - Kris Huygen
- Immunology Department, Scientific Institute of Public Health, Brussels, Belgium
| | - Jan Verschoor
- Department of Biochemistry, University of Pretoria, Pretoria, South Africa
| | - Mark S Baird
- School of Chemistry, Bangor University, Bangor, United Kingdom
| | - Johan Grooten
- Laboratory of Molecular Immunology, Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
| |
Collapse
|
45
|
Deletion of a dehydratase important for intracellular growth and cording renders rough Mycobacterium abscessus avirulent. Proc Natl Acad Sci U S A 2016; 113:E4228-37. [PMID: 27385830 PMCID: PMC4961194 DOI: 10.1073/pnas.1605477113] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Mycobacterium abscessus (Mabs) is a rapidly growing Mycobacterium and an emerging pathogen in humans. Transitioning from a smooth (S) high-glycopeptidolipid (GPL) producer to a rough (R) low-GPL producer is associated with increased virulence in zebrafish, which involves the formation of massive serpentine cords, abscesses, and rapid larval death. Generating a cord-deficient Mabs mutant would allow us to address the contribution of cording in the physiopathological signs of the R variant. Herein, a deletion mutant of MAB_4780, encoding a dehydratase, distinct from the β-hydroxyacyl-ACP dehydratase HadABC complex, was constructed in the R morphotype. This mutant exhibited an alteration of the mycolic acid composition and a pronounced defect in cording. This correlated with an extremely attenuated phenotype not only in wild-type but also in immunocompromised zebrafish embryos lacking either macrophages or neutrophils. The abolition of granuloma formation in embryos infected with the dehydratase mutant was associated with a failure to replicate in macrophages, presumably due to limited inhibition of the phagolysosomal fusion. Overall, these results indicate that MAB_4780 is required for Mabs to successfully establish acute and lethal infections. Therefore, targeting MAB_4780 may represent an attractive antivirulence strategy to control Mabs infections, refractory to most standard chemotherapeutic interventions. The combination of a dehydratase assay with a high-resolution crystal structure of MAB_4780 opens the way to identify such specific inhibitors.
Collapse
|
46
|
Taher SG, Al Dulayymi JR, Tima HG, Ali HM, Romano M, Baird MS. Synthesis of wax esters and related trehalose esters from Mycobacterium avium and other mycobacteria. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.05.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
47
|
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]
|
48
|
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.
Collapse
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
| |
Collapse
|
49
|
Ndlandla FL, Ejoh V, Stoltz AC, Naicker B, Cromarty AD, van Wyngaardt S, Khati M, Rotherham LS, Lemmer Y, Niebuhr J, Baumeister CR, Al Dulayymi JR, Swai H, Baird MS, Verschoor JA. Standardization of natural mycolic acid antigen composition and production for use in biomarker antibody detection to diagnose active tuberculosis. J Immunol Methods 2016; 435:50-9. [PMID: 27247168 DOI: 10.1016/j.jim.2016.05.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 04/21/2016] [Accepted: 05/24/2016] [Indexed: 10/21/2022]
Abstract
Mycobacterium tuberculosis, the causative agent of tuberculosis, is characterized by the abundance of species specific, antigenic cell wall lipids called mycolic acids. These wax-like molecules all share an identical, amphiphilic mycolic motif, but have different functional groups in a long hydrophobic hydrocarbon mero-chain that divide them into three main classes: alpha-, keto- and methoxy-mycolic acids. Whereas alpha-mycolic acids constitutively maintain an abundance of around 50%, the ratio of methoxy- to keto-mycolic acid types may vary depending on, among other things, the growth stage of M. tuberculosis. In human patients, antibodies to mycolic acids have shown potential as diagnostic serum biomarkers for active TB. Variations in mycolic acid composition affect the antigenic properties and can potentially compromise the precision of detection of anti-mycolic acids antibodies in patient sera to natural mixtures. We demonstrate this here with combinations of synthetic mycolic acid antigens, tested against TB patient and control sera. Combinations of methoxy- and α-mycolic acids are more antigenic than combinations of keto- and α-mycolic acids, showing the former to give a more sensitive test for TB biomarker antibodies. Natural mixtures of mycolic acids isolated from mature cultures of M. tuberculosis H37Rv give the same sensitivity as that with synthetic methoxy- and α-mycolic acids in combination, in a surface plasmon resonance inhibition biosensor test. To ensure that the antigenic activity of isolates of natural mycolic acids is reproducible, we cultured M. tuberculosis H37Rv on Middlebrook 7H10 solid agar plates to stationary growth phase in a standardized, optimal way. The proportions of mycolic acid classes in various batches of the isolates prepared from these cultures were compared to a commercially available natural mycolic acid isolate. LC-MS/MS and NMR data for quantitation of mycolic acids class compositions show that the variation in batches is small, suggesting that the quality of the results for anti-mycolic acid antibody detection in the TB patients should not be affected by different batches of natural mycolic acid antigens if prepared in a standard way.
Collapse
Affiliation(s)
- F L Ndlandla
- Polymers and Composites, Council for Scientific and Industrial Research, Pretoria, South Africa; Department of Biochemistry, University of Pretoria, South Africa
| | - V Ejoh
- Department of Biochemistry, University of Pretoria, South Africa
| | - A C Stoltz
- Division of Infectious Diseases, Faculty of Health Sciences, University of Pretoria, South Africa
| | - B Naicker
- Polymers and Composites, Council for Scientific and Industrial Research, Pretoria, South Africa; Department of Pharmacology, Faculty of Health Sciences, University of Pretoria, South Africa
| | - A D Cromarty
- Department of Pharmacology, Faculty of Health Sciences, University of Pretoria, South Africa
| | - S van Wyngaardt
- Department of Biochemistry, University of Pretoria, South Africa
| | - M Khati
- Biosciences, Council for Scientific and Industrial Research, Pretoria, South Africa
| | - L S Rotherham
- Biosciences, Council for Scientific and Industrial Research, Pretoria, South Africa
| | - Y Lemmer
- Polymers and Composites, Council for Scientific and Industrial Research, Pretoria, South Africa
| | - J Niebuhr
- Department of Biochemistry, University of Pretoria, South Africa
| | - C R Baumeister
- Department of Biochemistry, University of Pretoria, South Africa
| | | | - H Swai
- Polymers and Composites, Council for Scientific and Industrial Research, Pretoria, South Africa
| | - M S Baird
- School of Chemistry, Bangor University, Wales, UK
| | - J A Verschoor
- Department of Biochemistry, University of Pretoria, South Africa
| |
Collapse
|
50
|
In Vitro Investigation of Influences of Chitosan Nanoparticles on Fluorescein Permeation into Alveolar Macrophages. Pharm Res 2016; 33:1497-508. [PMID: 26951565 DOI: 10.1007/s11095-016-1893-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 02/24/2016] [Indexed: 02/04/2023]
Abstract
PURPOSE Pulmonary infection namely tuberculosis is characterized by alveolar macrophages harboring a large microbe population. The chitosan nanoparticles exhibit fast extracellular drug release in aqueous biological milieu. This study investigated the matrix effects of chitosan nanoparticles on extracellular drug diffusion into macrophages. METHODS Oligo, low, medium and high molecular weight chitosan nanoparticles were prepared by nanospray drying technique. These nanoparticles were incubated with alveolar macrophages in vitro and had model drug sodium fluorescein added into the same cell culture. The diffusion characteristics of sodium fluorescein and nanoparticle behavior were investigated using fluorescence microscopy, scanning electron microscopy, differential scanning calorimetry and Fourier transform infrared spectroscopy techniques. RESULTS The oligochitosan nanoparticles enabled macrophage membrane fluidization with the extent of sodium fluorescein entry into macrophages being directly governed by the nanoparticle loading. Using nanoparticles made of higher molecular weight chitosan, sodium fluorescein permeation into macrophages was delayed due to viscous chitosan diffusion barrier at membrane boundary. CONCLUSION Macrophage-chitosan nanoparticle interaction at membrane interface dictates drug migration into cellular domains.
Collapse
|