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Priyanka, Sharma S, Varma-Basil M, Sharma M. C-terminal region of Rv1039c (PPE15) protein of Mycobacterium tuberculosis targets host mitochondria to induce macrophage apoptosis. Apoptosis 2024:10.1007/s10495-024-01965-2. [PMID: 38615303 DOI: 10.1007/s10495-024-01965-2] [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] [Accepted: 04/04/2024] [Indexed: 04/15/2024]
Abstract
Mycobacterium tuberculosis (Mtb) genome possesses a unique family called Proline-Glutamate/Proline-Proline-Glutamate (PE/PPE) gene family, exclusive to pathogenic mycobacterium. Some of these proteins are known to play role in virulence and immune response modulation, but many are still uncharacterized. This study investigated the role of C-terminal region of Rv1039c (PPE15) in inducing mitochondrial perturbations and macrophage apoptosis. Our in-silico studies revealed the disordered, coiled, and hydrophobic C-terminal region in Rv1039c has similarity with C-terminal of mitochondria-targeting pro-apoptotic host proteins. Wild type Rv1039c and C-terminal deleted Rv1039c (Rv1039c-/-Cterm) recombinant proteins were purified and their M. smegmatis knock-in strains were constructed which were used for in-vitro experiments. Confocal microscopy showed localization of Rv1039c to mitochondria of PMA-differentiated THP1 macrophages; and reduced mitochondrial membrane depolarization and production of mitochondrial superoxides were observed in response to Rv1039c-/-Cterm in comparison to full-length Rv1039c. The C-terminal region of Rv1039c was found to activate caspases 3, 7 and 9 along with upregulated expression of pro-apoptotic genes like Bax and Bim. Rv1039c-/-Cterm also reduced the Cytochrome-C release from the mitochondria and the expression of AnnexinV/PI positive and TUNEL positive cells as compared to Rv1039c. Additionally, Rv1039c was observed to upregulate the TLR4-NF-κB-TNF-α signalling whereas the same was downregulated in response to Rv1039c-/-Cterm. These findings suggested that the C-terminal region of Rv1039c is a molecular mimic of pro-apoptotic host proteins which induce mitochondria-dependent macrophage apoptosis and evoke host immune response. These observations enhance our understanding about the role of PE/PPE proteins at host-pathogen interface.
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Affiliation(s)
- Priyanka
- DSKC BioDiscovery Laboratory, Department of Zoology, Miranda House, University of Delhi, Delhi, India
| | - Sadhna Sharma
- DSKC BioDiscovery Laboratory, Department of Zoology, Miranda House, University of Delhi, Delhi, India
| | - Mandira Varma-Basil
- Department of Microbiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Monika Sharma
- DSKC BioDiscovery Laboratory, Department of Zoology, Miranda House, University of Delhi, Delhi, India.
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Priyanka, Sharma S, Joshi H, Kumar C, Waseem R, Sharma M. Mycobacterium tuberculosis protein PPE15 (Rv1039c) possesses eukaryote-like SH3 domain that interferes with NADPH Oxidase assembly and Reactive Oxygen Species production. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119702. [PMID: 38408543 DOI: 10.1016/j.bbamcr.2024.119702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 02/19/2024] [Accepted: 02/21/2024] [Indexed: 02/28/2024]
Abstract
Inhibition of Reactive Oxygen Species (ROS) is one of the strategies that Mycobacterium tuberculosis (Mtb) employs as its defence mechanism. In this study, the role of PPE15 (Rv1039c), a late-stage protein, has been investigated in modulating the cellular ROS. We discovered PPE15 to be a secretory protein that downregulates ROS generation in THP1 macrophages. Our in-silico analysis revealed the presence of a eukaryote-like SH3 (SH3e) domain in PPE15. The predicted SH3e-domain of PPE15 was found to interact with cytosolic components of NADPH Oxidase (NOX), p67phox and p47phox through molecular docking. In-vitro experiments using THP1 macrophages showed a diminished NADP/NADPH ratio, indicating reduced NOX activity. We also observed increased levels of p67phox and p47phox in the cytoplasmic fraction of PPE15 treated macrophages as compared to the plasma membrane fraction. To understand the role of the SH3e-domain in ROS modulation, this domain was deleted from the full-length PPE15 (PPE15-/-SH3). We observed an increase in cellular ROS and NADP/NADPH ratio in response to PPE15-/-SH3 protein. The interaction of PPE15-/-SH3 with p67phox or p47phox was also reduced in the cytoplasm, indicating migration of NOX subunits to the plasma membrane. Additionally, M. smegmatis expressing PPE15 was observed to be resistant to oxidative stress with significant intracellular survival in THP1 macrophages as compared to M. smegmatis expressing PPE15-/-SH3. These observations suggest that the SH3e-domain of PPE15 interferes with ROS generation by sequestering NOX components that inhibit NOX assembly at the cell membrane. Therefore, PPE15 acts like a molecular mimic of SH3-domain carrying eukaryotic proteins that can be employed by Mtb at late stages of infection for its survival. These findings give us new insights about the pathogen evading strategy of Mtb which may help in improving the therapeutics for TB treatment.
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Affiliation(s)
- Priyanka
- DSKC BioDiscovery Laboratory and Department of Zoology, Miranda House, University of Delhi, Delhi, India.
| | - Sadhna Sharma
- DSKC BioDiscovery Laboratory and Department of Zoology, Miranda House, University of Delhi, Delhi, India.
| | - Hemant Joshi
- School of Biotechnology, Jawaharlal Nehru University, Delhi, India
| | - Chanchal Kumar
- Department of Microbiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Rashid Waseem
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
| | - Monika Sharma
- DSKC BioDiscovery Laboratory and Department of Zoology, Miranda House, University of Delhi, Delhi, India.
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Dargham T, Mallick I, Kremer L, Santucci P, Canaan S. Intrabacterial lipid inclusion-associated proteins: a core machinery conserved from saprophyte Actinobacteria to the human pathogen Mycobacterium tuberculosis. FEBS Open Bio 2023; 13:2306-2323. [PMID: 37872001 PMCID: PMC10699116 DOI: 10.1002/2211-5463.13721] [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: 09/05/2023] [Revised: 10/02/2023] [Accepted: 10/19/2023] [Indexed: 10/25/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb), the aetiologic agent of tuberculosis (TB), stores triacylglycerol (TAG) in the form of intrabacterial lipid inclusions (ILI) to survive and chronically persist within its host. These highly energetic molecules represent a major source of carbon to support bacterial persistence and reactivation, thus playing a leading role in TB pathogenesis. However, despite its physiological and clinical relevance, ILI metabolism in Mtb remains poorly understood. Recent discoveries have suggested that several ILI-associated proteins might be widely conserved across TAG-producing prokaryotes, but still very little is known regarding the nature and the biological functions of these proteins. Herein, we performed an in silico analysis of three independent ILI-associated proteomes previously reported to computationally define a potential core ILI-associated proteome, referred to as ILIome. Our investigation revealed the presence of 70 orthologous proteins that were strictly conserved, thereby defining a minimal ILIome core. We further narrowed our analysis to proteins involved in lipid metabolism and discuss here their putative biological functions, along with their molecular interactions and dynamics at the surface of these bacterial organelles. We also highlight the experimental limitations of the original proteomic investigations and of the present bioinformatic analysis, while describing new technological approaches and presenting biological perspectives in the field. The in silico investigation presented here aims at providing useful datasets that could constitute a scientific resource of broad interest for the mycobacterial community, with the ultimate goal of enlightening ILI metabolism in prokaryotes with a special emphasis on Mtb pathogenesis.
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Affiliation(s)
- Tonia Dargham
- Aix‐Marseille Univ, CNRS, LISM UMR 7255, IMM FR3479, IM2BFrance
- IHU Méditerranée InfectionAix‐Marseille Univ.France
| | - Ivy Mallick
- Aix‐Marseille Univ, CNRS, LISM UMR 7255, IMM FR3479, IM2BFrance
| | - Laurent Kremer
- Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM)Université de MontpellierFrance
- INSERM, Institut de Recherche en Infectiologie de MontpellierFrance
| | - Pierre Santucci
- Aix‐Marseille Univ, CNRS, LISM UMR 7255, IMM FR3479, IM2BFrance
| | - Stéphane Canaan
- Aix‐Marseille Univ, CNRS, LISM UMR 7255, IMM FR3479, IM2BFrance
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Bellini C, Vergara E, Bencs F, Fodor K, Bősze S, Krivić D, Bacsa B, Surguta SE, Tóvári J, Reljic R, Horváti K. Design and Characterization of a Multistage Peptide-Based Vaccine Platform to Target Mycobacterium tuberculosis Infection. Bioconjug Chem 2023; 34:1738-1753. [PMID: 37606258 PMCID: PMC10587871 DOI: 10.1021/acs.bioconjchem.3c00273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 08/09/2023] [Indexed: 08/23/2023]
Abstract
The complex immunopathology ofMycobacterium tuberculosis(Mtb) is one of the main challenges in developing a novel vaccine against this pathogen, particularly regarding eliciting protection against both active and latent stages. Multistage vaccines, which contain antigens expressed in both phases, represent a promising strategy for addressing this issue, as testified by the tuberculosis vaccine clinical pipeline. Given this approach, we designed and characterized a multistage peptide-based vaccine platform containing CD4+ and CD8+ T cell epitopes previously validated for inducing a relevant T cell response against Mtb. After preliminary screening, CFP10 (32-39), GlfT2 (4-12), HBHA (185-194), and PPE15 (1-15) were selected as promising candidates, and we proved that the PM1 pool of these peptides triggered a T cell response in Mtb-sensitized human peripheral blood mononuclear cells (PBMCs). Taking advantage of the use of thiol-maleimide chemoselective ligation, we synthesized a multiepitope conjugate (Ac-CGHP). Our results showed a structure-activity relationship between the conjugation and a higher tendency to fold and assume an ordered secondary structure. Moreover, the palmitoylated conjugate (Pal-CGHP) comprising the same peptide antigens was associated with an enhanced cellular uptake in human and murine antigen-presenting cells and a better immunogenicity profile. Immunization study, conducted in BALB/c mice, showed that Pal-CGHP induced a significantly higher T cell proliferation and production of IFNγ and TNFα over PM1 formulated in the Sigma Adjuvant System.
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Affiliation(s)
- Chiara Bellini
- MTA-TTK
Lendület “Momentum” Peptide-Based Vaccines Research
Group, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Budapest 1117, Hungary
- Hevesy
György PhD School of Chemistry, Eötvös
Loránd University, Budapest 1117, Hungary
| | - Emil Vergara
- Institute
for Infection and Immunity, St. George’s,
University of London, London SW17 0RE, U.K.
| | - Fruzsina Bencs
- Hevesy
György PhD School of Chemistry, Eötvös
Loránd University, Budapest 1117, Hungary
- Laboratory
of Structural Chemistry and Biology, Institute of Chemistry, Eötvös Loránd University, Budapest 1117, Hungary
| | - Kinga Fodor
- Department
of Laboratory Animal Science and Animal Protection, University of Veterinary Medicine, Budapest 1078, Hungary
| | - Szilvia Bősze
- ELKH-ELTE
Research Group of Peptide Chemistry, Eötvös Loránd
Research Network (ELKH), Eötvös
Loránd University, Budapest 1117, Hungary
| | - Denis Krivić
- Division
of Medical Physics and Biophysics, Gottfried Schatz Research Center, Medical University of Graz, 8010 Graz, Austria
| | - Bernadett Bacsa
- Division
of Medical Physics and Biophysics, Gottfried Schatz Research Center, Medical University of Graz, 8010 Graz, Austria
| | - Sára Eszter Surguta
- Department
of Experimental Pharmacology and National Tumor Biology Laboratory, National Institute of Oncology, Budapest 1122, Hungary
| | - József Tóvári
- Department
of Experimental Pharmacology and National Tumor Biology Laboratory, National Institute of Oncology, Budapest 1122, Hungary
| | - Rajko Reljic
- Institute
for Infection and Immunity, St. George’s,
University of London, London SW17 0RE, U.K.
| | - Kata Horváti
- MTA-TTK
Lendület “Momentum” Peptide-Based Vaccines Research
Group, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Budapest 1117, Hungary
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Anand PK, Kaur G, Saini V, Kaur J, Kaur J. N-terminal PPE domain plays an integral role in extracellular transportation and stability of the immunomodulatory Rv3539 protein of the Mycobacterium tuberculosis. Biochimie 2023; 213:30-40. [PMID: 37156406 DOI: 10.1016/j.biochi.2023.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 03/31/2023] [Accepted: 05/05/2023] [Indexed: 05/10/2023]
Abstract
Multigene PE/PPE family is exclusively present in mycobacterium species. Only few selected genes of this family have been characterized till date. Rv3539 was annotated as PPE63 with conserved PPE domain at N-terminal and PE-PPE at C-terminal. An α/β hydrolase structural fold, characteristic of lipase/esterase, was present in the PE-PPE domain. To assign the biochemical function to Rv3539, the corresponding gene was cloned in pET-32a (+) as full-length, PPE, and PE-PPE domains individually, followed by expression in E. Coli C41 (DE3). All three proteins demonstrated esterase activity. However, the enzyme activity in the N-terminal PPE domain was very low. The enzyme activity of Rv3539 and PE-PPE proteins was approximately same with the pNP-C4 as optimum substrate at 40 °C and pH 8.0. The loss of enzyme activity after mutating the predicted catalytic triad (Ser296Ala, Asp369Ala, and His395Ala) found only in the PE-PPE domain, confirmed the candidature of the bioinformatically predicted active site residue. The optimal activity and thermostability of the Rv3539 protein was altered by removing the PPE domain. CD-spectroscopy analysis confirmed the role of PPE domain to the thermostability of Rv3539 by maintaining the structural integrity at higher temperatures. The presence of the N-terminal PPE domain directed the Rv3539 protein to the cell membrane/wall and the extracellular compartment. The Rv3539 protein could generate humoral response in TB patients. Therefore, results demonstrated that Rv3539 demonstrated esterase activity. PE-PPE domain of Rv3539 is functionally automated, however, N-terminus domain played a role in protein stabilization and its transportation. Both domains participated in immunomodulation.
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Affiliation(s)
- Pradeep Kumar Anand
- Department of Biotechnology, BMS Block-1, South Campus, Panjab University, Chandigarh, 160014, India.
| | - Gagandeep Kaur
- Department of Biotechnology, BMS Block-1, South Campus, Panjab University, Chandigarh, 160014, India.
| | - Varinder Saini
- Department of Pulmonary Medicine, Government Medical College and Hospital, Chandigarh, India.
| | - Jasbinder Kaur
- Department of Biochemistry, Government Medical College and Hospital, Chandigarh, India.
| | - Jagdeep Kaur
- Department of Biotechnology, BMS Block-1, South Campus, Panjab University, Chandigarh, 160014, India.
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Guo F, Wei J, Song Y, Li B, Qian Z, Wang X, Wang H, Xu T. Immunological effects of the PE/PPE family proteins of Mycobacterium tuberculosis and related vaccines. Front Immunol 2023; 14:1255920. [PMID: 37841250 PMCID: PMC10569470 DOI: 10.3389/fimmu.2023.1255920] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 08/25/2023] [Indexed: 10/17/2023] Open
Abstract
Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis (Mtb), and its incidence and mortality are increasing. The BCG vaccine was developed in the early 20th century. As the most widely administered vaccine in the world, approximately 100 million newborns are vaccinated with BCG every year, which has saved tens of millions of lives. However, due to differences in region and race, the average protective rate of BCG in preventing tuberculosis in children is still not high in some areas. Moreover, because the immune memory induced by BCG will weaken with the increase of age, it is slightly inferior in preventing adult tuberculosis, and BCG revaccination cannot reduce the incidence of tuberculosis again. Research on the mechanism of Mtb and the development of new vaccines against TB are the main strategies for preventing and treating TB. In recent years, Pro-Glu motif-containing (PE) and Pro-Pro-Glu motif-containing (PPE) family proteins have been found to have an increasingly important role in the pathogenesis and chronic protracted infection observed in TB. The development and clinical trials of vaccines based on Mtb antigens are in progress. Herein, we review the immunological effects of PE/PPE proteins and the development of common PE/PPE vaccines.
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Affiliation(s)
- Fangzheng Guo
- Research Center of Laboratory, Bengbu Medical College, Bengbu, China
- Anhui Province Key Laboratory of Immunology in Chronic Diseases , Bengbu Medical College, Bengbu, China
| | - Jing Wei
- Research Center of Laboratory, Bengbu Medical College, Bengbu, China
- Anhui Province Key Laboratory of Immunology in Chronic Diseases , Bengbu Medical College, Bengbu, China
| | - Yamin Song
- Research Center of Laboratory, Bengbu Medical College, Bengbu, China
- Anhui Province Key Laboratory of Immunology in Chronic Diseases , Bengbu Medical College, Bengbu, China
| | - Baiqing Li
- Research Center of Laboratory, Bengbu Medical College, Bengbu, China
- Anhui Province Key Laboratory of Immunology in Chronic Diseases , Bengbu Medical College, Bengbu, China
- Department of Immunology, School of Laboratory, Bengbu Medical College, Bengbu, China
| | - Zhongqing Qian
- Research Center of Laboratory, Bengbu Medical College, Bengbu, China
- Anhui Province Key Laboratory of Immunology in Chronic Diseases , Bengbu Medical College, Bengbu, China
- Department of Immunology, School of Laboratory, Bengbu Medical College, Bengbu, China
| | - Xiaojing Wang
- Anhui Province Key Laboratory of Clinical and Preclinical Research in Respiratory Disease, Bengbu Medical College, Bengbu, China
| | - Hongtao Wang
- Research Center of Laboratory, Bengbu Medical College, Bengbu, China
- Anhui Province Key Laboratory of Immunology in Chronic Diseases , Bengbu Medical College, Bengbu, China
- Department of Immunology, School of Laboratory, Bengbu Medical College, Bengbu, China
| | - Tao Xu
- Research Center of Laboratory, Bengbu Medical College, Bengbu, China
- Anhui Province Key Laboratory of Immunology in Chronic Diseases , Bengbu Medical College, Bengbu, China
- Department of Clinical Laboratory, School of Laboratory, Bengbu Medical College, Bengbu, China
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Anand PK, Saini V, Kaur J, Kumar A, Kaur J. Cell wall and immune modulation by Rv1800 (PPE28) helps M. smegmatis to evade intracellular killing. Int J Biol Macromol 2023; 247:125837. [PMID: 37455004 DOI: 10.1016/j.ijbiomac.2023.125837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/27/2023] [Accepted: 07/13/2023] [Indexed: 07/18/2023]
Abstract
Rv1800 is predicted as PPE family protein found in pathogenic mycobacteria only. Under acidic stress, the rv1800 gene was expressed in M. tuberculosis H37Ra. In-silico study showed lipase/esterase activity in C-terminus PE-PPE domain having pentapeptide motif with catalytic Ser-Asp-His residue. Full-length Rv1800 and C-terminus PE-PPE domain proteins showed esterase activity with pNP-C4 at the optimum temperature of 40 °C and pH 8.0. However, the N-terminus PPE domain showed no esterase activity, but involved in thermostability of Rv1800 full-length protein. M. smegmatis expressing rv1800 (MS_Rv1800) showed altered colony morphology and a significant resistance to numerous environmental stresses, antibiotics and higher lipid content. In extracellular and membrane fraction, Rv1800 protein was detected, while C terminus PE-PPE was present in cytoplasm, suggesting the role of N-terminus PPE domain in transportation of protein. MS_Rv1800 infected macrophage showed higher intracellular survival and low production of ROS, NO and expression levels of iNOS and pro-inflammatory cytokines, while induced expression of the anti-inflammatory cytokines. The Rv1800, PPE and PE-PPE showed antibody-mediated immunity in MDR-TB and PTB patients. Overall, these results confirmed the esterase activity in the C-terminus and function of N-terminus in thermostabilization and transportation; predicting the role of Rv1800 in immune/lipid modulation to support intracellular mycobacterium survival.
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Affiliation(s)
- Pradeep Kumar Anand
- Department of Biotechnology, BMS Block-1, South Campus, Panjab University, Chandigarh, 160014, India
| | - Varinder Saini
- Department of Pulmonary Medicine, Government Medical College and Hospital, Chandigarh, India
| | - Jasbinder Kaur
- Department of Biochemistry, Government Medical College and Hospital, Chandigarh, India
| | - Arbind Kumar
- Department of Biotechnology, BMS Block-1, South Campus, Panjab University, Chandigarh, 160014, India
| | - Jagdeep Kaur
- Department of Biotechnology, BMS Block-1, South Campus, Panjab University, Chandigarh, 160014, India.
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Hüsler D, Stauffer P, Hilbi H. Tapping lipid droplets: A rich fat diet of intracellular bacterial pathogens. Mol Microbiol 2023; 120:194-209. [PMID: 37429596 DOI: 10.1111/mmi.15120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 07/12/2023]
Abstract
Lipid droplets (LDs) are dynamic and versatile organelles present in most eukaryotic cells. LDs consist of a hydrophobic core of neutral lipids, a phospholipid monolayer coat, and a variety of associated proteins. LDs are formed at the endoplasmic reticulum and have diverse roles in lipid storage, energy metabolism, membrane trafficking, and cellular signaling. In addition to their physiological cellular functions, LDs have been implicated in the pathogenesis of several diseases, including metabolic disorders, cancer, and infections. A number of intracellular bacterial pathogens modulate and/or interact with LDs during host cell infection. Members of the genera Mycobacterium, Legionella, Coxiella, Chlamydia, and Salmonella exploit LDs as a source of intracellular nutrients and membrane components to establish their distinct intracellular replicative niches. In this review, we focus on the biogenesis, interactions, and functions of LDs, as well as on their role in lipid metabolism of intracellular bacterial pathogens.
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Affiliation(s)
- Dario Hüsler
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Pia Stauffer
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Hubert Hilbi
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
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Anand PK, Kaur J. Rv3539 (PPE63) of Mycobacterium Tuberculosis Promotes Survival of Mycobacterium Smegmatis in Human Macrophages Cell Line via Cell Wall Modulation of Bacteria and Altering Host's Immune Response. Curr Microbiol 2023; 80:267. [PMID: 37401981 DOI: 10.1007/s00284-023-03360-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 05/31/2023] [Indexed: 07/05/2023]
Abstract
The modulation of host's immune response plays an important role in the intracellular survival of Mycobacterium tuberculosis. The intracellular pathogen counteracts environmental stresses with help of the expression of several genes. The M. tuberculosis genome encodes several immune-modulatory proteins including PE (proline-glutamic acid)/PPE (proline-proline-glutamic acid) superfamily proteins. It is unclear how the unique PE/PPE proteins superfamily contributes to survival under different stress and pathophysiology conditions. Previously, we showed that PPE63 (Rv3539) has C-terminal esterase extension and was localized as a membrane attached and in extracellular compartment. Therefore, the probability of these proteins interacting with the host to modulate the host immune response cannot be ruled out. The physiological role of PPE63 was characterized by expressing the PPE63 in the M. smegmatis, a non-pathogenic strain intrinsically deficient of PPE63. The recombinant M. smegmatis expressing PPE63 altered the colony morphology, lipid composition, and integrity of the cell wall. It provided resistance to multiple hostile environmental stress conditions and several antibiotics. MS_Rv3539 demonstrated higher infection and intracellular survival in comparison to the MS_Vec in the PMA-differentiated THP-1 cells. The decreased intracellular level of ROS, NO, and expression of iNOS was observed in THP-1 cells upon infection with MS_Rv3539 in comparison to MS_Vec. Further, the decrease in expression of pro-inflammatory cytokines like IL-6, TNF-α, and IL-1β and enhanced anti-inflammatory cytokines like IL-10, pointed toward its role in immune modulation. Overall this study suggested the role of Rv3539 in enhanced intracellular survival of M. smegmatis via cell wall modulation and altered immune response of host.
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Affiliation(s)
- Pradeep K Anand
- Department of Biotechnology, Panjab University, BMS Block-1, South Campus, Chandigarh, 160014, India
| | - Jagdeep Kaur
- Department of Biotechnology, Panjab University, BMS Block-1, South Campus, Chandigarh, 160014, India.
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10
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Ratna S, Daniel J. Stress-induced non-replicating Mycobacterium smegmatis incorporates exogenous fatty acids into glycopeptidolipids. Microb Pathog 2023; 174:105943. [PMID: 36502992 DOI: 10.1016/j.micpath.2022.105943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 11/03/2022] [Accepted: 12/08/2022] [Indexed: 12/13/2022]
Abstract
Nontuberculous mycobacteria (NTM) such as Mycobacterium smegmatis accumulate high levels of glycopeptidolipids (GPLs) on their outer surface. The biosynthesis of GPLs is critically linked to biofilm formation by NTM which also includes opportunistic pathogens such as Mycobacterium abscessus. Although GPLs have been investigated in many earlier studies, the biosynthesis of GPLs using exogenous fatty acids in M. smegmatis subjected to stresses encountered by mycobacteria during infection of the human body has not been studied. Therefore, we subjected M. smegmatis to different combinations of the three stresses of hypoxia, acidic pH and nutrient starvation and report here that the metabolic incorporation of radiolabeled long-chain fatty acids into alkali-stable GPLs was significantly increased under these stress conditions. Endogenously synthesized fatty acids were not preferred for GPL biosynthesis by M. smegmatis subjected to the triple stress combination. Our observations indicate that GPLs may play important roles in cell surface modifications associated with the non-replicating state of M. smegmatis. Our experimental model reported here would be useful in the further study of GPL biosynthesis from exogenous fatty acid sources in M. smegmatis subjected to hypoxia, nutrient starvation and acidic stress conditions and help in the screening of candidate drugs that target this biochemical pathway in pathogenic NTM.
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Affiliation(s)
- Sushanta Ratna
- Department of Biological Sciences, Purdue University Fort Wayne, Fort Wayne, IN, 46805, USA
| | - Jaiyanth Daniel
- Department of Biological Sciences, Purdue University Fort Wayne, Fort Wayne, IN, 46805, USA.
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Sánchez-Álvarez M, Del Pozo MÁ, Bosch M, Pol A. Insights Into the Biogenesis and Emerging Functions of Lipid Droplets From Unbiased Molecular Profiling Approaches. Front Cell Dev Biol 2022; 10:901321. [PMID: 35756995 PMCID: PMC9213792 DOI: 10.3389/fcell.2022.901321] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 05/17/2022] [Indexed: 11/30/2022] Open
Abstract
Lipid droplets (LDs) are spherical, single sheet phospholipid-bound organelles that store neutral lipids in all eukaryotes and some prokaryotes. Initially conceived as relatively inert depots for energy and lipid precursors, these highly dynamic structures play active roles in homeostatic functions beyond metabolism, such as proteostasis and protein turnover, innate immunity and defense. A major share of the knowledge behind this paradigm shift has been enabled by the use of systematic molecular profiling approaches, capable of revealing and describing these non-intuitive systems-level relationships. Here, we discuss these advances and some of the challenges they entail, and highlight standing questions in the field.
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Affiliation(s)
- Miguel Sánchez-Álvarez
- Cell and Developmental Biology Area, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
| | - Miguel Ángel Del Pozo
- Cell and Developmental Biology Area, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
| | - Marta Bosch
- Lipid Trafficking and Disease Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Department of Biomedical Sciences, Faculty of Medicine, Universitat de Barcelona, Barcelona, Spain
| | - Albert Pol
- Lipid Trafficking and Disease Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Department of Biomedical Sciences, Faculty of Medicine, Universitat de Barcelona, Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
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12
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Agarwal P, Gordon S, Martinez FO. Foam Cell Macrophages in Tuberculosis. Front Immunol 2022; 12:775326. [PMID: 34975863 PMCID: PMC8714672 DOI: 10.3389/fimmu.2021.775326] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 11/29/2021] [Indexed: 12/18/2022] Open
Abstract
Mycobacterium tuberculosis infects primarily macrophages in the lungs. Infected macrophages are surrounded by other immune cells in well organised structures called granulomata. As part of the response to TB, a type of macrophage loaded with lipid droplets arises which we call Foam cell macrophages. They are macrophages filled with lipid laden droplets, which are synthesised in response to increased uptake of extracellular lipids, metabolic changes and infection itself. They share the appearance with atherosclerosis foam cells, but their lipid contents and roles are different. In fact, lipid droplets are immune and metabolic organelles with emerging roles in Tuberculosis. Here we discuss lipid droplet and foam cell formation, evidence regarding the inflammatory and immune properties of foam cells in TB, and address gaps in our knowledge to guide further research.
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Affiliation(s)
- Pooja Agarwal
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Siamon Gordon
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan City, Taiwan.,Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Fernando O Martinez
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
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13
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Patil V, Jain V. Understanding Metabolic Remodeling in Mycobacterium smegmatis to Overcome Energy Exigency and Reductive Stress Under Energy-Compromised State. Front Microbiol 2021; 12:722229. [PMID: 34539614 PMCID: PMC8440910 DOI: 10.3389/fmicb.2021.722229] [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: 06/08/2021] [Accepted: 08/11/2021] [Indexed: 12/04/2022] Open
Abstract
Mycobacteria such as Mycobacterium tuberculosis, the causative agent of tuberculosis that annually kills several million people worldwide, and Mycobacterium smegmatis, the non-pathogenic fast-growing mycobacteria, require oxidative phosphorylation to meet their energy requirements. We have previously shown that deletion of one of the two copies of atpD gene that codes for the ATP synthase β-subunit establishes an energy-compromised state in M. smegmatis. Here we report that upon such deletion, a major routing of electron flux occurs through the less energy-efficient complexes of its respiratory chain. ΔatpD bacterium also shows an increased reduced state which is further confirmed by the overexpression of WhiB3, a major redox sensor. We show a substantial modulation of the biosynthesis of cell wall associated lipids and triacylglycerol (TAG). An accumulation of TAG-containing lipid bodies is further confirmed by using 14C oleate incorporation. Interestingly, the mutant also shows an overexpression of TAG-degrading lipase genes, and the intracellular lipolytic enzymes mediate TAG hydrolysis for their utilization as energy source. We believe that our in vitro energy-depleted model will allow us to explore the critical link between energy metabolism, redox homeostasis, and lipid biosynthesis during ATP-depleted state, which will enhance our understanding of the bacterial adaptation, and will allow us to identify novel drug targets to counter mycobacterial infections.
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Affiliation(s)
- Varsha Patil
- Microbiology and Molecular Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal, India
| | - Vikas Jain
- Microbiology and Molecular Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal, India
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14
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Mallick I, Santucci P, Poncin I, Point V, Kremer L, Cavalier JF, Canaan S. Intrabacterial lipid inclusions in mycobacteria: unexpected key players in survival and pathogenesis? FEMS Microbiol Rev 2021; 45:6283747. [PMID: 34036305 DOI: 10.1093/femsre/fuab029] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 05/21/2021] [Indexed: 12/12/2022] Open
Abstract
Mycobacterial species, including Mycobacterium tuberculosis, rely on lipids to survive and chronically persist within their hosts. Upon infection, opportunistic and strict pathogenic mycobacteria exploit metabolic pathways to import and process host-derived free fatty acids, subsequently stored as triacylglycerols under the form of intrabacterial lipid inclusions (ILI). Under nutrient-limiting conditions, ILI constitute a critical source of energy that fuels the carbon requirements and maintain redox homeostasis, promoting bacterial survival for extensive periods of time. In addition to their basic metabolic functions, these organelles display multiple other biological properties, emphasizing their central role in the mycobacterial lifecycle. However, despite of their importance, the dynamics of ILI metabolism and their contribution to mycobacterial adaptation/survival in the context of infection has not been thoroughly documented. Herein, we provide an overview of the historical ILI discoveries, their characterization, and current knowledge regarding the micro-environmental stimuli conveying ILI formation, storage and degradation. We also review new biological systems to monitor the dynamics of ILI metabolism in extra- and intracellular mycobacteria and describe major molecular actors in triacylglycerol biosynthesis, maintenance and breakdown. Finally, emerging concepts regarding to the role of ILI in mycobacterial survival, persistence, reactivation, antibiotic susceptibility and inter-individual transmission are also discuss.
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Affiliation(s)
- Ivy Mallick
- Aix-Marseille Univ, CNRS, LISM, IMM FR3479, Marseille, France.,IHU Méditerranée Infection, Aix-Marseille Univ., Marseille, France
| | - Pierre Santucci
- Aix-Marseille Univ, CNRS, LISM, IMM FR3479, Marseille, France
| | - Isabelle Poncin
- Aix-Marseille Univ, CNRS, LISM, IMM FR3479, Marseille, France
| | - Vanessa Point
- Aix-Marseille Univ, CNRS, LISM, IMM FR3479, Marseille, France
| | - Laurent Kremer
- Institut de Recherche en Infectiologie de Montpellier (IRIM), CNRS, UMR 9004, Université de Montpellier, Montpellier, France.,IRIM, INSERM, Montpellier, France
| | | | - Stéphane Canaan
- Aix-Marseille Univ, CNRS, LISM, IMM FR3479, Marseille, France
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15
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Allen PE, Martinez JJ. Modulation of Host Lipid Pathways by Pathogenic Intracellular Bacteria. Pathogens 2020; 9:pathogens9080614. [PMID: 32731350 PMCID: PMC7460438 DOI: 10.3390/pathogens9080614] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 07/17/2020] [Accepted: 07/25/2020] [Indexed: 12/22/2022] Open
Abstract
Lipids are a broad group of molecules required for cell maintenance and homeostasis. Various intracellular pathogens have developed mechanisms of modulating and sequestering host lipid processes for a large array of functions for both bacterial and host cell survival. Among the host cell lipid functions that intracellular bacteria exploit for infection are the modulation of host plasma membrane microdomains (lipid rafts) required for efficient bacterial entry; the recruitment of specific lipids for membrane integrity of intracellular vacuoles; and the utilization of host lipid droplets for the regulation of immune responses and for energy production through fatty acid β-oxidation and oxidative phosphorylation. The majority of published studies on the utilization of these host lipid pathways during infection have focused on intracellular bacterial pathogens that reside within a vacuole during infection and, thus, have vastly different requirements for host lipid metabolites when compared to those intracellular pathogens that are released into the host cytosol upon infection. Here we summarize the mechanisms by which intracellular bacteria sequester host lipid species and compare the modulation of host lipid pathways and metabolites during host cell infection by intracellular pathogens residing in either a vacuole or within the cytosol of infected mammalian cells. This review will also highlight common and unique host pathways necessary for intracellular bacterial growth that could potentially be targeted for therapeutic intervention.
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16
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Sarathy JP, Dartois V. Caseum: a Niche for Mycobacterium tuberculosis Drug-Tolerant Persisters. Clin Microbiol Rev 2020; 33:e00159-19. [PMID: 32238365 PMCID: PMC7117546 DOI: 10.1128/cmr.00159-19] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Caseum, the central necrotic material of tuberculous lesions, is a reservoir of drug-recalcitrant persisting mycobacteria. Caseum is found in closed nodules and in open cavities connecting with an airway. Several commonly accepted characteristics of caseum were established during the preantibiotic era, when autopsies of deceased tuberculosis (TB) patients were common but methodologies were limited. These pioneering studies generated concepts such as acidic pH, low oxygen tension, and paucity of nutrients being the drivers of nonreplication and persistence in caseum. Here we review widely accepted beliefs about the caseum-specific stress factors thought to trigger the shift of Mycobacterium tuberculosis to drug tolerance. Our current state of knowledge reveals that M. tuberculosis is faced with a lipid-rich diet rather than nutrient deprivation in caseum. Variable caseum pH is seen across lesions, possibly transiently acidic in young lesions but overall near neutral in most mature lesions. Oxygen tension is low in the avascular caseum of closed nodules and high at the cavity surface, and a gradient of decreasing oxygen tension likely forms toward the cavity wall. Since caseum is largely made of infected and necrotized macrophages filled with lipid droplets, the microenvironmental conditions encountered by M. tuberculosis in foamy macrophages and in caseum bear many similarities. While there remain a few knowledge gaps, these findings constitute a solid starting point to develop high-throughput drug discovery assays that combine the right balance of oxygen tension, pH, lipid abundance, and lipid species to model the profound drug tolerance of M. tuberculosis in caseum.
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Affiliation(s)
- Jansy P Sarathy
- Center for Discovery and Innovation, Hackensack Meridian School of Medicine at Seton Hall University, Nutley, New Jersey, USA
| | - Véronique Dartois
- Center for Discovery and Innovation, Hackensack Meridian School of Medicine at Seton Hall University, Nutley, New Jersey, USA
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17
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Mittal P, Sinha R, Kumar A, Singh P, Ngasainao MR, Singh A, Singh IK. Focusing on DNA Repair and Damage Tolerance Mechanisms in Mycobacterium tuberculosis: An Emerging Therapeutic Theme. Curr Top Med Chem 2020; 20:390-408. [PMID: 31924156 DOI: 10.2174/1568026620666200110114322] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 09/02/2019] [Accepted: 10/10/2019] [Indexed: 11/22/2022]
Abstract
Tuberculosis (TB) is one such disease that has become a nuisance in the world scenario and one of the most deadly diseases of the current times. The etiological agent of tuberculosis, Mycobacterium tuberculosis (M. tb) kills millions of people each year. Not only 1.7 million people worldwide are estimated to harbor M. tb in the latent form but also 5 to 15 percent of which are expected to acquire an infection during a lifetime. Though curable, a long duration of drug regimen and expense leads to low patient adherence. The emergence of multi-, extensive- and total- drug-resistant strains of M. tb further complicates the situation. Owing to high TB burden, scientists worldwide are trying to design novel therapeutics to combat this disease. Therefore, to identify new drug targets, there is a growing interest in targeting DNA repair pathways to fight this infection. Thus, this review aims to explore DNA repair and damage tolerance as an efficient target for drug development by understanding M. tb DNA repair and tolerance machinery and its regulation, its role in pathogenesis and survival, mutagenesis, and consequently, in the development of drug resistance.
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Affiliation(s)
- Pooja Mittal
- Molecular Biology Research Lab, Department of Zoology, Deshbandhu College, University of Delhi, Kalkaji, New Delhi, 110019, India
| | - Rajesh Sinha
- Molecular Biology Research Lab, Department of Zoology, Deshbandhu College, University of Delhi, Kalkaji, New Delhi, 110019, India
| | - Amit Kumar
- Department of Botany, Hansraj College, University of Delhi, Delhi, 110007, India
| | - Pooja Singh
- Public Health Research Institute, NJMS-Rutgers University, New Jersey, United States
| | - Moses Rinchui Ngasainao
- Department of Zoology, Deshbandhu College, University of Delhi, Kalkaji, New Delhi, 110019, India
| | - Archana Singh
- Department of Botany, Hansraj College, University of Delhi, Delhi, 110007, India.,Department of Molecular Ecology, Max-Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, D-07745 Jena, Germany
| | - Indrakant K Singh
- Molecular Biology Research Lab, Department of Zoology, Deshbandhu College, University of Delhi, Kalkaji, New Delhi, 110019, India.,Department of Molecular Ecology, Max-Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, D-07745 Jena, Germany
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18
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Lipid Droplets: A Significant but Understudied Contributor of Host⁻Bacterial Interactions. Cells 2019; 8:cells8040354. [PMID: 30991653 PMCID: PMC6523240 DOI: 10.3390/cells8040354] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 04/05/2019] [Accepted: 04/12/2019] [Indexed: 12/13/2022] Open
Abstract
Lipid droplets (LDs) are cytosolic lipid storage organelles that are important for cellular lipid metabolism, energy homeostasis, cell signaling, and inflammation. Several bacterial, viral and protozoal pathogens exploit host LDs to promote infection, thus emphasizing the importance of LDs at the host–pathogen interface. In this review, we discuss the thus far reported relation between host LDs and bacterial pathogens including obligate and facultative intracellular bacteria, and extracellular bacteria. Although there is less evidence for a LD–extracellular bacterial interaction compared to interactions with intracellular bacteria, in this review, we attempt to compare the bacterial mechanisms that target LDs, the host signaling pathways involved and the utilization of LDs by these bacteria. Many intracellular bacteria employ unique mechanisms to target host LDs and potentially obtain nutrients and lipids for vacuolar biogenesis and/or immune evasion. However, extracellular bacteria utilize LDs to either promote host tissue damage or induce host death. We also identify several areas that require further investigation. Along with identifying LD interactions with bacteria besides the ones reported, the precise mechanisms of LD targeting and how LDs benefit pathogens should be explored for the bacteria discussed in the review. Elucidating LD–bacterial interactions promises critical insight into a novel host–pathogen interaction.
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19
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Maurya RK, Bharti S, Krishnan MY. Triacylglycerols: Fuelling the Hibernating Mycobacterium tuberculosis. Front Cell Infect Microbiol 2019; 8:450. [PMID: 30687647 PMCID: PMC6333902 DOI: 10.3389/fcimb.2018.00450] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 12/18/2018] [Indexed: 01/13/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) has the remarkable ability to persist with a modified metabolic status and phenotypic drug tolerance for long periods in the host without producing symptoms of active tuberculosis. These persisters may reactivate to cause active disease when the immune system becomes disrupted or compromised. Thus, the infected hosts with the persisters serve as natural reservoir of the deadly pathogen. Understanding the host and bacterial factors contributing to Mtb persistence is important to devise strategies to tackle the Mtb persisters. Host lipids act as the major source of carbon and energy for Mtb. Fatty acids derived from the host cells are converted to triacylglycerols (triglycerides or TAG) and stored in the bacterial cytoplasm. TAG serves as a dependable, long-term energy source of lesser molecular mass than other storage molecules like glycogen. TAG are found in substantial amounts in the mycobacterial cell wall. This review discusses the production, accumulation and possible roles of TAG in mycobacteria, pointing out the aspects that remain to be explored. Finally, the essentiality of TAG synthesis for Mtb is discussed with implications for identification of intervention strategies.
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Affiliation(s)
- Rahul Kumar Maurya
- Microbiology Division, CSIR-Central Drug Research Institute, Lucknow, India
| | - Suman Bharti
- Microbiology Division, CSIR-Central Drug Research Institute, Lucknow, India
| | - Manju Y Krishnan
- Microbiology Division, CSIR-Central Drug Research Institute, Lucknow, India
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20
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Sinha R, Singh P, Nath O, Mangangcha IR, Kumar A, Singh IK. Structural and functional insights into putative TAG accumulating hydrolase protein (Rv1179c) of Mycobacterium tuberculosis H37Rv. GENE REPORTS 2018. [DOI: 10.1016/j.genrep.2018.08.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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21
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Delineating the Physiological Roles of the PE and Catalytic Domains of LipY in Lipid Consumption in Mycobacterium-Infected Foamy Macrophages. Infect Immun 2018; 86:IAI.00394-18. [PMID: 29986895 DOI: 10.1128/iai.00394-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 07/03/2018] [Indexed: 12/29/2022] Open
Abstract
Within tuberculous granulomas, a subpopulation of Mycobacterium tuberculosis resides inside foamy macrophages (FM) that contain abundant cytoplasmic lipid bodies (LB) filled with triacylglycerol (TAG). Upon fusion of LB with M. tuberculosis-containing phagosomes, TAG is hydrolyzed and reprocessed by the bacteria into their own lipids, which accumulate as intracytosolic lipid inclusions (ILI). This phenomenon is driven by many mycobacterial lipases, among which LipY participates in the hydrolysis of host and bacterial TAG. However, the functional contribution of LipY's PE domain to TAG hydrolysis remains unclear. Here, enzymatic studies were performed to compare the lipolytic activities of recombinant LipY and its truncated variant lacking the N-terminal PE domain, LipY(ΔPE). Complementarily, an FM model was used where bone marrow-derived mouse macrophages were infected with M. bovis BCG strains either overexpressing LipY or LipY(ΔPE) or carrying a lipY deletion mutation prior to being exposed to TAG-rich very-low-density lipoprotein (VLDL). Results indicate that truncation of the PE domain correlates with increased TAG hydrolase activity. Quantitative electron microscopy analyses showed that (i) in the presence of lipase inhibitors, large ILI (ILI+3) were not formed because of an absence of LB due to inhibition of VLDL-TAG hydrolysis or inhibition of LB-neutral lipid hydrolysis by mycobacterial lipases, (ii) ILI+3 profiles in the strain overexpressing LipY(ΔPE) were reduced, and (iii) the number of ILI+3 profiles in the ΔlipY mutant was reduced by 50%. Overall, these results delineate the role of LipY and its PE domain in host and mycobacterial lipid consumption and show that additional mycobacterial lipases take part in these processes.
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22
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Association of Mycobacterium Proteins with Lipid Droplets. J Bacteriol 2018; 200:JB.00240-18. [PMID: 29760207 DOI: 10.1128/jb.00240-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 05/07/2018] [Indexed: 12/27/2022] Open
Abstract
Mycobacterium tuberculosis is a global pathogen of significant medical importance. A key aspect of its life cycle is the ability to enter into an altered physiological state of nonreplicating persistence during latency and resist elimination by the host immune system. One mechanism by which M. tuberculosis facilitates its survival during latency is by producing and metabolizing intracytoplasmic lipid droplets (LDs). LDs are quasi-organelles consisting of a neutral lipid core such as triacylglycerol surrounded by a phospholipid monolayer and proteins. We previously reported that PspA (phage shock protein A) associates with LDs produced in Mycobacterium In particular, the loss or overproduction of PspA alters LD homeostasis in Mycobacterium smegmatis and attenuates the survival of M. tuberculosis during nonreplicating persistence. Here, M. tuberculosis PspA (PspAMtb) and a ΔpspA M. smegmatis mutant were used as model systems to investigate the mechanism by which PspA associates with LDs and determine if other Mycobacterium proteins associate with LDs using a mechanism similar to that for PspA. Through this work, we established that the amphipathic helix present in the first α-helical domain (H1) of PspA is both necessary and sufficient for the targeting of this protein to LDs. Furthermore, we identified other Mycobacterium proteins that also possess amphipathic helices similar to PspA H1, including a subset that localize to LDs. Altogether, our results indicate that amphipathic helices may be an important mechanism by which proteins target LDs in prokaryotes.IMPORTANCEMycobacterium spp. are one of the few prokaryotes known to produce lipid droplets (LDs), and their production has been linked to aspects of persistent infection by M. tuberculosis Unfortunately, little is known about LD production in these organisms, including how LDs are formed, their function, or the identity of proteins that associate with them. In this study, an established M. tuberculosis LD protein and a surrogate Mycobacterium host were used as model systems to study the interactions between proteins and LDs in bacteria. Through these studies, we identified a commonly occurring protein motif that is able to facilitate the association of proteins to LDs in prokaryotes.
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23
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Identification and Evaluation of Novel Protective Antigens for the Development of a Candidate Tuberculosis Subunit Vaccine. Infect Immun 2018; 86:IAI.00014-18. [PMID: 29661928 PMCID: PMC6013653 DOI: 10.1128/iai.00014-18] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 04/06/2018] [Indexed: 12/03/2022] Open
Abstract
The development of a vaccine against tuberculosis (TB), a disease caused by Mycobacterium tuberculosis, is urgently needed. The only currently available vaccine, M. bovis BCG, has variable efficacy. One approach in the global vaccine development effort is focused on boosting BCG using subunit vaccines. The identification of novel antigens for inclusion in subunit vaccines is a critical step in the TB vaccine development pathway. We selected four novel mycobacterial antigens recognized during the course of human infection. A replication-deficient chimpanzee adenovirus (ChAdOx1) was constructed to express each antigen individually, and these vectors were evaluated for protective efficacy in murine M. tuberculosis challenge experiments. One antigen, PPE15 (Rv1039c), conferred significant and reproducible protection when administered alone and as a boost to BCG vaccination. We identified immunodominant epitopes to define the protective immune responses using tetramers and intravascular staining. Lung parenchymal CD4+ and CD8+ CXCR3+ KLRG1− T cells, previously associated with protection against M. tuberculosis, were enriched in the vaccinated groups compared to the control groups. Further work to evaluate the protective efficacy of PPE15 in more stringent preclinical animal models, together with the identification of further novel protective antigens using this selection strategy, is now merited.
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24
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Bothra A, Arumugam P, Panchal V, Menon D, Srivastava S, Shankaran D, Nandy A, Jaisinghani N, Singh A, Gokhale RS, Gandotra S, Rao V. Phospholipid homeostasis, membrane tenacity and survival of Mtb in lipid rich conditions is determined by MmpL11 function. Sci Rep 2018; 8:8317. [PMID: 29844505 PMCID: PMC5974182 DOI: 10.1038/s41598-018-26710-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 05/18/2018] [Indexed: 11/09/2022] Open
Abstract
The mycobacterial cell wall is a chemically complex array of molecular entities that dictate the pathogenesis of Mycobacterium tuberculosis. Biosynthesis and maintenance of this dynamic entity in mycobacterial physiology is still poorly understood. Here we demonstrate a requirement for M. tuberculosis MmpL11 in the maintenance of the cell wall architecture and stability in response to surface stress. In the presence of a detergent like Tyloxapol, a mmpL11 deletion mutant suffered from a severe growth attenuation as a result of altered membrane polarity, permeability and severe architectural damages. This mutant failed to tolerate permissible concentrations of cis-fatty acids suggesting its increased sensitivity to surface stress, evident as smaller colonies of the mutant outgrown from lipid rich macrophage cultures. Additionally, loss of MmpL11 led to an altered cellular fatty acid flux in the mutant: reduced incorporation into membrane cardiolipin was associated with an increased flux into the cellular triglyceride pool. This increase in storage lipids like triacyl glycerol (TAG) was associated with the altered metabolic state of higher dormancy-associated gene expression and decreased sensitivity to frontline TB drugs. This study provides a detailed mechanistic insight into the function of mmpL11 in stress adaptation of mycobacteria.
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Affiliation(s)
- Ankur Bothra
- CSIR- Institute of Genomics and Integrative Biology, New Delhi, India
| | | | - Vipul Panchal
- CSIR- Institute of Genomics and Integrative Biology, New Delhi, India
| | - Dilip Menon
- CSIR- Institute of Genomics and Integrative Biology, New Delhi, India
| | - Sonali Srivastava
- CSIR- Institute of Genomics and Integrative Biology, New Delhi, India
| | - Deepthi Shankaran
- CSIR- Institute of Genomics and Integrative Biology, New Delhi, India
| | - Ananya Nandy
- CSIR- Institute of Genomics and Integrative Biology, New Delhi, India
| | | | - Archana Singh
- CSIR- Institute of Genomics and Integrative Biology, New Delhi, India
| | - Rajesh S Gokhale
- CSIR- Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research, CSIR-Central Road Research Institute, New Delhi, India.,National Institute of Immunology, New Delhi, India
| | - Sheetal Gandotra
- CSIR- Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research, CSIR-Central Road Research Institute, New Delhi, India
| | - Vivek Rao
- CSIR- Institute of Genomics and Integrative Biology, New Delhi, India. .,Academy of Scientific and Innovative Research, CSIR-Central Road Research Institute, New Delhi, India.
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25
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Liang YS, Qi WT, Guo W, Wang CL, Hu ZB, Li AK. Genistein and daidzein induce apoptosis of colon cancer cells by inhibiting the accumulation of lipid droplets. Food Nutr Res 2018; 62:1384. [PMID: 29849534 PMCID: PMC5965345 DOI: 10.29219/fnr.v62.1384] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 03/19/2018] [Accepted: 04/04/2018] [Indexed: 01/05/2023] Open
Abstract
Aim The purpose of this study was to investigate the possible mechanisms of genistein (GEN) and daidzein (DAI) in inducing apoptosis of colon cancer cells by inhibition of lipid droplets (LDs) accumulation. Methods HT-29 cells were used and treated by GEN or DAI in this paper. LDs accumulation was induced and inhibited by oleic acid (OA) and C75, respectively. The expression changes of LDs-related markers were confirmed by semiquantitative real time-PCR (RT–PCR), Western blotting, and immunofluorescence staining. Results GEN and DAI effectively reduced the LDs accumulation and downregulated the expression of Perilipin-1, ADRP and Tip-47 family proteins and vimentin levels. GEN and DAI significantly induced the mRNA expression of PPAR-γ, Fas, FABP, glycerol-3-phosphate acyltransferase (GPAT3), and microsomal TG transfer protein (MTTP), and reduced the mRNA expression of UCP2. Furthermore, the results showed a decrease of PI3K expression by GEN and DAI when compared with OA treatment, and both GEN and DAI can increase the expression of FOXO3a and caspase-8 significantly when these proteins were decreased by OA treatment. GEN is more effective than DAI in inducing cell apoptosis. Conclusion Our results demonstrated that GEN and DAI inhibit the accumulation of LDs by regulating LDs-related factors and lead to a final apoptosis of colon cancer cells. These results may provide important new insights into the possible molecular mechanisms of isoflavones in anti-obesity and anti-tumor functions.
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Affiliation(s)
- Yu-Si Liang
- 1Cereals & Oils Nutrition Research Group, Academy of State Administration of Grain (ASAG), Beijing, The People's Republic of China.,2Key Laboratory of Food Safety and Sanitation, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin, The People's Republic of China
| | - Wen-Tao Qi
- 1Cereals & Oils Nutrition Research Group, Academy of State Administration of Grain (ASAG), Beijing, The People's Republic of China
| | - Weiqun Guo
- 1Cereals & Oils Nutrition Research Group, Academy of State Administration of Grain (ASAG), Beijing, The People's Republic of China
| | - Chun-Ling Wang
- 2Key Laboratory of Food Safety and Sanitation, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin, The People's Republic of China
| | - Ze-Bin Hu
- 3Institute for In Vitro Diagnostic Reagents Control, The National Institutes for Food and Drug Control (NIFDC), Beijing, The People's Republic of China
| | - Ai-Ke Li
- 1Cereals & Oils Nutrition Research Group, Academy of State Administration of Grain (ASAG), Beijing, The People's Republic of China
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Martin A, Daniel J. The ABC transporter Rv1272c of Mycobacterium tuberculosis enhances the import of long-chain fatty acids in Escherichia coli. Biochem Biophys Res Commun 2018; 496:667-672. [DOI: 10.1016/j.bbrc.2018.01.115] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 01/17/2018] [Indexed: 10/18/2022]
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The mycobacterial Rv1551 glycerol-3-phosphate acyltransferase enhances phospholipid biosynthesis in cell lysates of Escherichia coli. Microb Pathog 2017; 113:269-275. [DOI: 10.1016/j.micpath.2017.10.050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 09/27/2017] [Accepted: 10/26/2017] [Indexed: 01/03/2023]
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Gupta VK, Kumar MM, Singh D, Bisht D, Sharma S. Drug targets in dormant Mycobacterium tuberculosis: can the conquest against tuberculosis become a reality? Infect Dis (Lond) 2017; 50:81-94. [DOI: 10.1080/23744235.2017.1377346] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Affiliation(s)
- Vivek Kumar Gupta
- Department of Biochemistry, National JALMA Institute for Leprosy and Other Mycobacterial Diseases (ICMR), Agra, India
| | - M. Madhan Kumar
- Department of Immunology, National JALMA Institute for Leprosy and Other Mycobacterial Diseases (ICMR), Agra, India
| | - Dharmendra Singh
- Department of Biochemistry, National JALMA Institute for Leprosy and Other Mycobacterial Diseases (ICMR), Agra, India
| | - Deepa Bisht
- Department of Biochemistry, National JALMA Institute for Leprosy and Other Mycobacterial Diseases (ICMR), Agra, India
| | - Shweta Sharma
- Department of Biochemistry, National JALMA Institute for Leprosy and Other Mycobacterial Diseases (ICMR), Agra, India
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Yang G, Luo T, Sun C, Yuan J, Peng X, Zhang C, Zhai X, Bao L. PPE27 in Mycobacterium smegmatis Enhances Mycobacterial Survival and Manipulates Cytokine Secretion in Mouse Macrophages. J Interferon Cytokine Res 2017; 37:421-431. [PMID: 28829246 DOI: 10.1089/jir.2016.0126] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Guoping Yang
- Laboratory of Infection and Immunity, School of Basic Medical Science, West China Center of Medical Sciences, Sichuan University, Chengdu, China
| | - Tao Luo
- Laboratory of Infection and Immunity, School of Basic Medical Science, West China Center of Medical Sciences, Sichuan University, Chengdu, China
| | - Changfeng Sun
- Laboratory of Infection and Immunity, School of Basic Medical Science, West China Center of Medical Sciences, Sichuan University, Chengdu, China
| | - Jinning Yuan
- Laboratory of Infection and Immunity, School of Basic Medical Science, West China Center of Medical Sciences, Sichuan University, Chengdu, China
| | - Xuan Peng
- Laboratory of Infection and Immunity, School of Basic Medical Science, West China Center of Medical Sciences, Sichuan University, Chengdu, China
| | - Chunxi Zhang
- Laboratory of Infection and Immunity, School of Basic Medical Science, West China Center of Medical Sciences, Sichuan University, Chengdu, China
| | - Xiaoqian Zhai
- Laboratory of Infection and Immunity, School of Basic Medical Science, West China Center of Medical Sciences, Sichuan University, Chengdu, China
| | - Lang Bao
- Laboratory of Infection and Immunity, School of Basic Medical Science, West China Center of Medical Sciences, Sichuan University, Chengdu, China
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Daniel J, Kapoor N, Sirakova T, Sinha R, Kolattukudy P. The perilipin-like PPE15 protein inMycobacterium tuberculosisis required for triacylglycerol accumulation under dormancy-inducing conditions. Mol Microbiol 2016. [DOI: 10.1111/mmi.13560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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31
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Santucci P, Bouzid F, Smichi N, Poncin I, Kremer L, De Chastellier C, Drancourt M, Canaan S. Experimental Models of Foamy Macrophages and Approaches for Dissecting the Mechanisms of Lipid Accumulation and Consumption during Dormancy and Reactivation of Tuberculosis. Front Cell Infect Microbiol 2016; 6:122. [PMID: 27774438 PMCID: PMC5054039 DOI: 10.3389/fcimb.2016.00122] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 09/22/2016] [Indexed: 12/11/2022] Open
Abstract
Despite a slight decline since 2014, tuberculosis (TB) remains the major deadly infectious disease worldwide with about 1.5 million deaths each year and with about one-third of the population being latently infected with Mycobacterium tuberculosis, the etiologic agent of TB. During primo-infection, the recruitment of immune cells leads to the formation of highly organized granulomas. Among the different cells, one outstanding subpopulation is the foamy macrophage (FM), characterized by the abundance of triacylglycerol-rich lipid bodies (LB). M. tuberculosis can reside in FM, where it acquires, from host LB, the neutral lipids which are subsequently processed and stored by the bacilli in the form of intracytosolic lipid inclusions (ILI). Although host LB can be viewed as a reservoir of nutrients for the pathogen during latency, the molecular mechanisms whereby intraphagosomal mycobacteria interact with LB and assimilate the LB-derived lipids are only beginning to be understood. Past studies have emphasized that these physiological processes are critical to the M. tuberculosis infectious-life cycle, for propagation of the infection, establishment of the dormancy state and reactivation of the disease. In recent years, several animal and cellular models have been developed with the aim of dissecting these complex processes and of determining the nature and contribution of their key players. Herein, we review some of the in vitro and in vivo models which allowed to gain significant insight into lipid accumulation and consumption in M. tuberculosis, two important events that are directly linked to pathogenicity, granuloma formation/maintenance and survival of the tubercle bacillus under non-replicative conditions. We also discuss the advantages and limitations of each model, hoping that this will serve as a guide for future investigations dedicated to persistence and innovative therapeutic approaches against TB.
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Affiliation(s)
- Pierre Santucci
- Aix-Marseille Université, Centre National de la Recherche Scientifique, EIPL Marseille, France
| | - Feriel Bouzid
- Aix-Marseille Université, Centre National de la Recherche Scientifique, EIPLMarseille, France; Aix-Marseille Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Institut de Recherche pour le Développement, URMITEMarseille, France
| | - Nabil Smichi
- Aix-Marseille Université, Centre National de la Recherche Scientifique, EIPLMarseille, France; Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé, Centre National de la Recherche Scientifique FRE3689, Université de MontpellierMontpellier, France
| | - Isabelle Poncin
- Aix-Marseille Université, Centre National de la Recherche Scientifique, EIPL Marseille, France
| | - Laurent Kremer
- Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé, Centre National de la Recherche Scientifique FRE3689, Université de MontpellierMontpellier, France; Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé, Institut National de la Santé et de la Recherche MédicaleMontpellier, France
| | - Chantal De Chastellier
- Aix-Marseille Université, Centre National de la Recherche Scientifique, EIPL Marseille, France
| | - Michel Drancourt
- Aix-Marseille Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Institut de Recherche pour le Développement, URMITE Marseille, France
| | - Stéphane Canaan
- Aix-Marseille Université, Centre National de la Recherche Scientifique, EIPL Marseille, France
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