1
|
Manjunath P, Ahmad J, Samal J, Rani A, Sheikh JA, Zarin S, Ahuja Y, Alam A, Hasnain SE, Ehtesham NZ. Expression of a unique M. tuberculosis DNA MTase Rv1509 in M. smegmatis alters the gene expression pattern and enhances virulence. Front Microbiol 2024; 15:1344857. [PMID: 38803374 PMCID: PMC11129820 DOI: 10.3389/fmicb.2024.1344857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 04/15/2024] [Indexed: 05/29/2024] Open
Abstract
Mycobacterium tuberculosis (M. tb) genome encompasses 4,173 genes, about a quarter of which remain uncharacterized and hypothetical. Considering the current limitations associated with the diagnosis and treatment of tuberculosis, it is imperative to comprehend the pathomechanism of the disease and host-pathogen interactions to identify new drug targets for intervention strategies. Using in-silico comparative genome analysis, we identified one of the M. tb genes, Rv1509, as a signature protein exclusively present in M. tb. To explore the role of Rv1509, a likely methyl transferase, we constructed a knock-in Mycobacterium smegmatis (M. smegmatis) constitutively expressing Rv1509 (Ms_Rv1509). The Ms_Rv1509 led to differential expression of many transcriptional regulator genes as assessed by RNA-seq analysis. Further, in-vitro and in-vivo studies demonstrated an enhanced survival of Ms_Rv1509 inside the host macrophages. Ms_Rv1509 also promoted phagolysosomal escape inside macrophages to boost bacterial replication and dissemination. In-vivo infection studies revealed that Ms_Rv1509 survives better than BCG and causes pathological manifestations in the pancreas after intraperitoneal infection. Long-time survival of Ms_Rv1509 resulted in lymphocyte migration, increased T regulatory cells, giant cell formation, and likely granuloma formation in the pancreas, pointing toward the role of Rv1509 in M. tb pathogenesis.
Collapse
Affiliation(s)
- P. Manjunath
- Inflammation Biology and Cell Signaling Laboratory, National Institute of Pathology, New Delhi, India
- Department of Biotechnology, Jamia Hamdard, New Delhi, India
| | - Javeed Ahmad
- Molecular Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Jasmine Samal
- Inflammation Biology and Cell Signaling Laboratory, National Institute of Pathology, New Delhi, India
| | - Anshu Rani
- Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, India
| | | | - Sheeba Zarin
- Department of Biotechnology, Jamia Hamdard, New Delhi, India
- Department of Life Science, Sharda School of Basic Sciences and Research, Sharda University, Greater Noida, Uttar Pradesh, India
| | - Yashika Ahuja
- Department of Life Science, Sharda School of Basic Sciences and Research, Sharda University, Greater Noida, Uttar Pradesh, India
| | - Anwar Alam
- Department of Biotechnology, Sharda School of Engineering Sciences and Technology, Sharda University, Greater Noida, Uttar Pradesh, India
| | - Seyed E. Hasnain
- Department of Life Science, Sharda School of Basic Sciences and Research, Sharda University, Greater Noida, Uttar Pradesh, India
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, New Delhi, India
| | - Nasreen Z. Ehtesham
- Department of Life Science, Sharda School of Basic Sciences and Research, Sharda University, Greater Noida, Uttar Pradesh, India
| |
Collapse
|
2
|
Wei L, Liu L, Meng Z, Qi K, Gao X, Feng J, Luo J. Recognition of Mycobacterium tuberculosis by macrophage Toll-like receptor and its role in autophagy. Inflamm Res 2024; 73:753-770. [PMID: 38563966 DOI: 10.1007/s00011-024-01864-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 12/25/2023] [Accepted: 02/20/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND The pathogen responsible for tuberculosis is called Mycobacterium tuberculosis. Its interaction with macrophages has a significant impact on the onset and progression of the disease. METHODS The respiratory pathway allows Mycobacterium tuberculosis to enter the body's lungs where it battles immune cells before being infected latently or actively. In the progress of tuberculosis, Mycobacterium tuberculosis activates the body's immune system and creates inflammatory factors, which cause tissue inflammation to infiltrate and the creation of granulomas, which seriously harms the body. Toll-like receptors of macrophage can mediate host recognition of Mycobacterium tuberculosis, initiate immune responses, and participate in macrophage autophagy. New host-directed therapeutic approaches targeting autophagy for drug-resistant Mycobacterium tuberculosis have emerged, providing new ideas for the effective treatment of tuberculosis. CONCLUSIONS In-depth understanding of the mechanisms by which macrophage autophagy interacts with intracellular Mycobacterium tuberculosis, as well as the study of potent and specific autophagy-regulating molecules, will lead to much-needed advances in drug discovery and vaccine design, which will improve the prevention and treatment of human tuberculosis.
Collapse
Affiliation(s)
- Linna Wei
- Department of Immunology, Zunyi Medical University, Zunyi, 563000, China
| | - Liping Liu
- Department of Immunology, Zunyi Medical University, Zunyi, 563000, China
| | - Zudi Meng
- Department of Immunology, Zunyi Medical University, Zunyi, 563000, China
| | - Kai Qi
- Department of Immunology, Zunyi Medical University, Zunyi, 563000, China
| | - Xuehan Gao
- Department of Immunology, Zunyi Medical University, Zunyi, 563000, China
| | - Jihong Feng
- Department of Oncology, Lishui People's Hospital, Sixth Affiliated Hospital of Wenzhou Medical University, Lishui, 323000, Zhejiang, China
| | - Junmin Luo
- Department of Immunology, Zunyi Medical University, Zunyi, 563000, China.
| |
Collapse
|
3
|
Medha, Priyanka, Sharma S, Sharma M. PE_PGRS45 (Rv2615c) protein of Mycobacterium tuberculosis perturbs mitochondria of macrophages. Immunol Cell Biol 2023. [PMID: 37565603 DOI: 10.1111/imcb.12677] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 03/23/2023] [Accepted: 07/19/2023] [Indexed: 08/12/2023]
Abstract
The PE_PGRS proteins have coevolved with the antigenic ESX-V secretory system and are abundant in pathogenic Mycobacterium. Only a few PE_PGRS proteins have been characterized, and research suggests their role in organelle targeting, cell death pathways, calcium (Ca2+ ) homeostasis and disease pathogenesis. The PE_PGRS45 (Rv2615c) protein was predicted to contain mitochondria targeting sequences by in silico evaluation. Therefore, we investigated the targeting of the Rv2615c protein to host mitochondria and its effect on mitochondrial functions. In vitro experiments showed the Rv2615c protein colocalized with the mitochondria and led to morphological mitochondrial perturbations. Recombinant Rv2615c was observed to cause increased levels of intracellular reactive oxygen species and the adenosine diphosphate-to-adenosine triphosphate ratio. The Rv2615c protein also induced mitochondrial membrane depolarization and the generation of mitochondrial superoxide. We observed the release of cytochrome C into the cytoplasm and increased expression of proapoptotic genes Bax and Bim with no significant change in anti-apoptotic Bcl2 in Rv2615c-stimulated THP1 macrophages. Ca2+ is a key signaling molecule in tuberculosis pathogenesis, modulating host cell responses. As reported for other PE_PGRS proteins, Rv2615c also has Ca2+ -binding motifs and thus can modulate calcium homeostasis in the host. We also observed a high level of Ca2+ influx in THP1 macrophages stimulated with Rv2615c. Based on these findings, we suggest that Rv2615c may be an effector protein that could contribute to disease pathogenesis by targeting host mitochondria.
Collapse
Affiliation(s)
- Medha
- DSKC BioDiscovery Laboratory, Department of Zoology, Miranda House, University of Delhi, Delhi, India
| | - 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
| | - Monika Sharma
- DSKC BioDiscovery Laboratory, Department of Zoology, Miranda House, University of Delhi, Delhi, India
| |
Collapse
|
4
|
D'Souza C, Kishore U, Tsolaki AG. The PE-PPE Family of Mycobacterium tuberculosis: Proteins in Disguise. Immunobiology 2023; 228:152321. [PMID: 36805109 DOI: 10.1016/j.imbio.2022.152321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 12/22/2022] [Accepted: 12/27/2022] [Indexed: 12/31/2022]
Abstract
Mycobacterium tuberculosis has thrived in parallel with humans for millennia, and despite our efforts, M. tuberculosis continues to plague us, currently infecting a third of the world's population. The success of M. tuberculosis has recently been attributed, in part, to the PE-PPE family; a unique collection of 168 proteins fundamentally involved in the pathogenesis of M. tuberculosis. The PE-PPE family proteins have been at the forefront of intense research efforts since their discovery in 1998 and whilst our knowledge and understanding has significantly advanced over the last two decades, many important questions remain to be elucidated. This review consolidates and examines the vast body of existing literature regarding the PE-PPE family proteins, with respect to the latest developments in elucidating their evolution, structure, subcellular localisation, function, and immunogenicity. This review also highlights significant inconsistencies and contradictions within the field. Additionally, possible explanations for these knowledge gaps are explored. Lastly, this review poses many important questions, which need to be addressed to complete our understanding of the PE-PPE family, as well as highlighting the challenges associated with studying this enigmatic family of proteins. Further research into the PE-PPE family, together with technological advancements in genomics and proteomics, will undoubtedly improve our understanding of the pathogenesis of M. tuberculosis, as well as identify key targets/candidates for the development of novel drugs, diagnostics, and vaccines.
Collapse
Affiliation(s)
- Christopher D'Souza
- Biosciences, Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge UB8 3PH, United Kingdom
| | - Uday Kishore
- Department of Veterinary Medicine, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Anthony G Tsolaki
- Biosciences, Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge UB8 3PH, United Kingdom.
| |
Collapse
|
5
|
Role of C-terminal domain of Mycobacterium tuberculosis PE6 (Rv0335c) protein in host mitochondrial stress and macrophage apoptosis. Apoptosis 2023; 28:136-165. [PMID: 36258102 PMCID: PMC9579591 DOI: 10.1007/s10495-022-01778-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2022] [Indexed: 11/02/2022]
Abstract
PE/PPE proteins of Mycobacterium tuberculosis (Mtb) target the host organelles to dictate the outcome of infection. This study investigated the significance of PE6/Rv0335c protein's unique C-terminal in causing host mitochondrial perturbations and apoptosis. In-silico analysis revealed that similar to eukaryotic apoptotic Bcl2 proteins, Rv0335c had disordered, hydrophobic C-terminal and two BH3-like motifs in which one was located at C-terminal. Also, Rv0335c's N terminal had mitochondrial targeting sequence. Since, C-terminal of Bcl2 proteins are crucial for mitochondria targeting and apoptosis; it became relevant to evaluate the role of Rv0335c's C-terminal domain in modulating host mitochondrial functions and apoptosis. To confirm this, in-vitro experiments were conducted with Rv0335c whole protein and Rv0335c∆Cterm (C-terminal domain deleted Rv0335c) protein. Rv0335c∆Cterm caused significant reduction in mitochondrial perturbations and Caspase-mediated apoptosis of THP1 macrophages in comparison to Rv0335c. However, the deletion of C-terminal domain didn't affect Rv0335c's ability to localize to mitochondria. Nine Ca2+ binding residues were predicted within Rv0335c and four of them were at the C-terminal. In-vitro studies confirmed that Rv0335c caused significant increase in intracellular calcium influx whereas Rv0335c∆Cterm had insignificant effect on Ca2+ influx. Rv0335c has been reported to be a TLR4 agonist and, we observed a significant reduction in the expression of TLR4-HLA-DR-TNF-α in response to Rv0335c∆Cterm protein also suggesting the role of Rv0335c's C-terminal domain in host-pathogen interaction. These findings indicate the possibility of Rv0335c as a molecular mimic of eukaryotic Bcl2 proteins which equips it to cause host mitochondrial perturbations and apoptosis that may facilitate pathogen persistence.
Collapse
|
6
|
Boradia V, Frando A, Grundner C. The Mycobacterium tuberculosis PE15/PPE20 complex transports calcium across the outer membrane. PLoS Biol 2022; 20:e3001906. [PMID: 36441815 PMCID: PMC9731449 DOI: 10.1371/journal.pbio.3001906] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 12/08/2022] [Accepted: 11/04/2022] [Indexed: 11/29/2022] Open
Abstract
The mechanisms by which nutrients traverse the Mycobacterium tuberculosis (Mtb) outer membrane remain mostly unknown and, in the absence of classical porins, likely involve specialized transport systems. Calcium ions (Ca2+) are an important nutrient and serve as a second messenger in eukaryotes, but whether bacteria have similar Ca2+ signaling systems is not well understood. To understand the basis for Ca2+ transport and signaling in Mtb, we determined Mtb's transcriptional response to Ca2+. Overall, only few genes changed expression, suggesting a limited role of Ca2+ as a transcriptional regulator. However, 2 of the most strongly down-regulated genes were the pe15 and ppe20 genes that code for members of a large family of proteins that localize to the outer membrane and comprise many intrinsically disordered proteins. PE15 and PPE20 formed a complex and PPE20 directly bound Ca2+. Ca2+-associated phenotypes such as increased ATP consumption and biofilm formation were reversed in a pe15/ppe20 knockout (KO) strain, suggesting a direct role in Ca2+ homeostasis. To test whether the PE15/PPE20 complex has a role in Ca2+ transport across the outer membrane, we created a fluorescence resonance energy transfer (FRET)-based Ca2+ reporter strain. A pe15/ppe20 KO in the FRET background showed a specific and selective loss of Ca2+ influx that was dependent on the presence of an intact outer cell wall. These data show that PE15/PPE20 form a Ca2+-binding protein complex that selectively imports Ca2+, show a distinct transport function for an intrinsically disordered protein, and support the emerging idea of a general family-wide role of PE/PPE proteins as idiosyncratic transporters across the outer membrane.
Collapse
Affiliation(s)
- Vishant Boradia
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
| | - Andrew Frando
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
| | - Christoph Grundner
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
- Department of Pediatrics, University of Washington, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
- * E-mail:
| |
Collapse
|
7
|
Bhatt P, Sharma M, Prakash Sharma P, Rathi B, Sharma S. Mycobacterium tuberculosis dormancy regulon proteins Rv2627c and Rv2628 as Toll like receptor agonist and as potential adjuvant. Int Immunopharmacol 2022; 112:109238. [PMID: 36116151 DOI: 10.1016/j.intimp.2022.109238] [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: 05/01/2022] [Revised: 09/02/2022] [Accepted: 09/05/2022] [Indexed: 11/19/2022]
Abstract
During latency, DosR proteins of Mycobacterium tuberculosis (M.tb) get activated and help the bacterium to remain dormant. We have shown earlier that 2 such proteins Rv2627c and Rv2628 are immunogenic and induce a TH1 kind of immune response. In this study, through in-vitro experiments we have confirmed that Rv2627c and Rv2628 proteins act as protein Toll-Like Receptor (TLR) agonist-adjuvant. Rv2627c and Rv2628 stimulated THP-1 macrophages showed an increased expression of TLR2, TLR4 and co-stimulatory molecules CD40, CD80, CD86 and antigen presenting molecule HLA-DR. Further studies also found enhanced expression of downstream signaling molecules of TLR activation like MyD88, NF-κB-p65 and pro-inflammatory cytokines. Inhibition studies using TLR blocking antibodies decreased the expression of co-stimulatory molecules, MyD88, NF-κB-p65, and pro-inflammatory cytokines. Rv2627c and Rv2628 stimulation of HEK-TLR2 reporter cell line confirmed the interaction of these proteins with TLR2. Moreover, molecular docking and simulations of Rv2627c and Rv2628 proteins with TLR2 and TLR4 showed stable interactions. The adjuvant activity of Rv2628 was further validated by a protein adjuvanted with pre-clinically validated peptides as multi-epitope vaccine construct which showed good binding with TLR2 and TLR4 and activate dendritic cells and induce sustained pro-inflammatory cytokine response by C-ImmSim analysis. We propose that our vaccine construct will produce a better immune response than BCG and can be taken up as a post-exposure therapeutic subunit vaccine along with standard TB therapy. We also anticipate that our construct can be taken up as a protein adjuvant with other vaccine candidates as these can activate macrophages through TLR signaling.
Collapse
Affiliation(s)
- Parul Bhatt
- DSKC BioDiscovery Lab, Department of Zoology, Miranda House, University of Delhi, Delhi 110007, India.
| | - Monika Sharma
- DSKC BioDiscovery Lab, Department of Zoology, Miranda House, University of Delhi, Delhi 110007, India
| | - Prem Prakash Sharma
- Laboratory for Translational Chemistry and Drug Discovery, Department of Chemistry, Hansraj College, University of Delhi, Delhi 110007, India
| | - Brijesh Rathi
- Laboratory for Translational Chemistry and Drug Discovery, Department of Chemistry, Hansraj College, University of Delhi, Delhi 110007, India
| | - Sadhna Sharma
- DSKC BioDiscovery Lab, Department of Zoology, Miranda House, University of Delhi, Delhi 110007, India.
| |
Collapse
|
8
|
Cellular and Molecular Mechanisms in Mycobacterial Infection. Int J Mol Sci 2022; 23:ijms23137205. [PMID: 35806210 PMCID: PMC9266448 DOI: 10.3390/ijms23137205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 06/27/2022] [Indexed: 01/27/2023] Open
Abstract
Tuberculosis (TB), caused by the bacillus Mycobacterium tuberculosis (Mtb), remains a leading cause of death by infectious disease, overshadowed only recently by the COVID-19 pandemic [...]
Collapse
|
9
|
The Mycobacterium tuberculosis PE_PGRS Protein Family Acts as an Immunological Decoy to Subvert Host Immune Response. Int J Mol Sci 2022; 23:ijms23010525. [PMID: 35008950 PMCID: PMC8745494 DOI: 10.3390/ijms23010525] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/03/2021] [Accepted: 12/15/2021] [Indexed: 02/04/2023] Open
Abstract
Mycobacterium tuberculosis (M.tb) is a successful pathogen that can reside within the alveolar macrophages of the host and can survive in a latent stage. The pathogen has evolved and developed multiple strategies to resist the host immune responses. M.tb escapes from host macrophage through evasion or subversion of immune effector functions. M.tb genome codes for PE/PPE/PE_PGRS proteins, which are intrinsically disordered, redundant and antigenic in nature. These proteins perform multiple functions that intensify the virulence competence of M.tb majorly by modulating immune responses, thereby affecting immune mediated clearance of the pathogen. The highly repetitive, redundant and antigenic nature of PE/PPE/PE_PGRS proteins provide a critical edge over other M.tb proteins in terms of imparting a higher level of virulence and also as a decoy molecule that masks the effect of effector molecules, thereby modulating immuno-surveillance. An understanding of how these proteins subvert the host immunological machinery may add to the current knowledge about M.tb virulence and pathogenesis. This can help in redirecting our strategies for tackling M.tb infections.
Collapse
|