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Paroha R, Wang J, Lee S. PDCD4 as a marker of mTOR pathway activation and therapeutic target in mycobacterial infections. Microbiol Spectr 2024; 12:e0006224. [PMID: 38912807 PMCID: PMC11302300 DOI: 10.1128/spectrum.00062-24] [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: 01/26/2024] [Accepted: 05/20/2024] [Indexed: 06/25/2024] Open
Abstract
Programmed cell death protein 4 (PDCD4) is instrumental in regulating a range of cellular processes such as translation, apoptosis, signal transduction, and inflammatory responses. There is a notable inverse correlation between PDCD4 and the mammalian target of rapamycin (mTOR) pathway, which is integral to cellular growth control. Activation of mTOR is associated with the degradation of PDCD4. Although the role of PDCD4 is well established in oncogenesis and immune response regulation, its function in mycobacterial infections and its interplay with the mTOR pathway necessitate further elucidation. This study investigates the modulation of PDCD4 expression in the context of mycobacterial infections, revealing a consistent pattern of downregulation across diverse mycobacterial species. This observation underscores the potential utility of PDCD4 as a biomarker for assessing mTOR pathway activation during such infections. Building on this finding, we employed a novel approach using PDCD4-based mTOR (Tor)-signal-indicator (TOSI) reporter cells for the high-throughput screening of FDA-approved drugs, focusing on mTOR inhibitors. This methodology facilitated the identification of several agents, inclusive of known mTOR inhibitors, which upregulated PDCD4 expression and concurrently exhibited efficacy in impeding mycobacterial proliferation within macrophages. These results not only reinforce the significance of PDCD4 as a pivotal marker in the understanding of infectious diseases, particularly mycobacterial infections, but also illuminate its potential in the identification of mTOR inhibitors, thereby contributing to the advancement of therapeutic strategies. IMPORTANCE This study emphasizes the critical role of the mammalian target of rapamycin (mTOR) pathway in macrophage responses to mycobacterial infections, elucidating how mycobacteria activate mTOR, resulting in PDCD4 degradation. The utilization of the (Tor)-signal-indicator (TOSI) vector for real-time monitoring of mTOR activity represents a significant advancement in understanding mTOR regulation during mycobacterial infection. These findings deepen our comprehension of mycobacteria's innate immune mechanisms and introduce PDCD4 as a novel marker for mTOR activity in infectious diseases. Importantly, this research laid the groundwork for high-throughput screening of mTOR inhibitors using FDA-approved drugs, offering the potential for repurposing treatments against mycobacterial infections. The identification of drugs that inhibit mTOR activation opens new avenues for host-directed therapies, marking a significant step forward in combating tuberculosis and other mycobacterial diseases.
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Affiliation(s)
- Ruchi Paroha
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, USA
| | - Jia Wang
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, USA
| | - Sunhee Lee
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, USA
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Ramachandran G, Yeruva CV, Swarup G, Raghunand TR. A cytoprotective role for optineurin during mycobacterial infection of macrophages. Biochem Biophys Rep 2024; 38:101672. [PMID: 38434142 PMCID: PMC10907145 DOI: 10.1016/j.bbrep.2024.101672] [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: 12/26/2023] [Revised: 02/10/2024] [Accepted: 02/20/2024] [Indexed: 03/05/2024] Open
Abstract
Autophagy has emerged as a critical innate immune mechanism for host elimination of intracellular pathogens, however, the role of the autophagy receptor Optineurin during mycobacterial infection is not fully understood. To address this lacuna, we infected bone marrow-derived macrophages (BMDMs) derived from Optn+/+ and Optn-/- mice with Mycobacterium smegmatis, and observed the infection outcome at sequential time points. While low multiplicity of infection (MOI) did not show any significant difference between BMDMs from the two groups, at high MOI Optn-/- mice-derived BMDMs showed significantly lower colony forming unit counts, as well as lower cell counts at 12 h and 24 h post-infection. Quantification of cell numbers and nuclear morphologies at various time points post-infection indicated a markedly higher cell death in the Optineurin-deficient macrophages. Optineurin-deficient BMDMs showed significantly lower levels of the autophagosomal protein LC3-II upon infection, indicating a potential role for Optineurin in regulating autophagy during mycobacterial infection. Moreover, when stimulated by bacterial LPS, Optineurin deficient macrophages, showed altered levels of the inflammatory cytokine pro-IL-1β. These observations taken together suggest a novel regulatory role for Optineurin during mycobacterial infection. Its deficiency leads to an impairment in macrophage responses, directly impacting the pathophysiology of infection.
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Affiliation(s)
| | | | - Ghanshyam Swarup
- CSIR - Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, 500007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Tirumalai R. Raghunand
- CSIR - Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, 500007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
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Wright K, Han DJ, Song R, de Silva K, Plain KM, Purdie AC, Shepherd A, Chin M, Hortle E, Wong JJL, Britton WJ, Oehlers SH. Zebrafish tsc1 and cxcl12a increase susceptibility to mycobacterial infection. Life Sci Alliance 2024; 7:e202302523. [PMID: 38307625 PMCID: PMC10837051 DOI: 10.26508/lsa.202302523] [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: 12/13/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 02/04/2024] Open
Abstract
Regulation of host miRNA expression is a contested node that controls the host immune response to mycobacterial infection. The host must counter subversive efforts of pathogenic mycobacteria to launch a protective immune response. Here, we examine the role of miR-126 in the zebrafish-Mycobacterium marinum infection model and identify a protective role for infection-induced miR-126 through multiple effector pathways. We identified a putative link between miR-126 and the tsc1a and cxcl12a/ccl2/ccr2 signalling axes resulting in the suppression of non-tnfa expressing macrophage accumulation at early M. marinum granulomas. Mechanistically, we found a detrimental effect of tsc1a expression that renders zebrafish embryos susceptible to higher bacterial burden and increased cell death via mTOR inhibition. We found that macrophage recruitment driven by the cxcl12a/ccl2/ccr2 signalling axis was at the expense of the recruitment of classically activated tnfa-expressing macrophages and increased cell death around granulomas. Together, our results delineate putative pathways by which infection-induced miR-126 may shape an effective immune response to M. marinum infection in zebrafish embryos.
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Affiliation(s)
- Kathryn Wright
- https://ror.org/0384j8v12 Tuberculosis Research Program at the Centenary Institute, The University of Sydney, Camperdown, Australia
- https://ror.org/0384j8v12 Faculty of Science, Sydney School of Veterinary Science, The University of Sydney, Sydney, Australia
- https://ror.org/0384j8v12 Directed Evolution Research Program at the Centenary Institute, The University of Sydney, Camperdown, Australia
- https://ror.org/0384j8v12 Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia
| | - Darryl Jy Han
- https://ror.org/036wvzt09 A*STAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Renhua Song
- https://ror.org/0384j8v12 Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia
- https://ror.org/0384j8v12 Epigenetics and RNA Biology Laboratory, Charles Perkins Centre, The University of Sydney, Camperdown, Australia
| | - Kumudika de Silva
- https://ror.org/0384j8v12 Faculty of Science, Sydney School of Veterinary Science, The University of Sydney, Sydney, Australia
| | - Karren M Plain
- https://ror.org/0384j8v12 Faculty of Science, Sydney School of Veterinary Science, The University of Sydney, Sydney, Australia
| | - Auriol C Purdie
- https://ror.org/0384j8v12 Faculty of Science, Sydney School of Veterinary Science, The University of Sydney, Sydney, Australia
| | - Ava Shepherd
- https://ror.org/0384j8v12 Directed Evolution Research Program at the Centenary Institute, The University of Sydney, Camperdown, Australia
| | - Maegan Chin
- https://ror.org/0384j8v12 Directed Evolution Research Program at the Centenary Institute, The University of Sydney, Camperdown, Australia
| | - Elinor Hortle
- https://ror.org/0384j8v12 Tuberculosis Research Program at the Centenary Institute, The University of Sydney, Camperdown, Australia
- https://ror.org/0384j8v12 Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia
- Faculty of Science, School of Life Sciences, Centre for Inflammation and University of Technology Sydney, Sydney, Australia
| | - Justin J-L Wong
- https://ror.org/0384j8v12 Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia
- https://ror.org/0384j8v12 Epigenetics and RNA Biology Laboratory, Charles Perkins Centre, The University of Sydney, Camperdown, Australia
| | - Warwick J Britton
- https://ror.org/0384j8v12 Tuberculosis Research Program at the Centenary Institute, The University of Sydney, Camperdown, Australia
- https://ror.org/0384j8v12 Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia
- Department of Clinical Immunology, Royal Prince Alfred Hospital, Camperdown, Australia
| | - Stefan H Oehlers
- https://ror.org/0384j8v12 Tuberculosis Research Program at the Centenary Institute, The University of Sydney, Camperdown, Australia
- https://ror.org/0384j8v12 Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia
- https://ror.org/036wvzt09 A*STAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
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Tatano Y, Shimizu T, Sano C, Tomioka H. Roles of autophagy in killing of mycobacterial pathogens by host macrophages - Effects of some medicinal plants. Eur J Microbiol Immunol (Bp) 2024; 14:26-36. [PMID: 38349363 PMCID: PMC10895364 DOI: 10.1556/1886.2023.00062] [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: 12/22/2023] [Accepted: 01/29/2024] [Indexed: 02/24/2024] Open
Abstract
Autophagy is a cellular stress-induced intracellular process, through which damaged cellular components are decomposed via lysosomal degradation. This process plays important roles in host innate immunity, particularly the elimination of intracellular pathogens inside host macrophages. A more detailed understanding of the roles of autophagic events in the effective manifestation of macrophagic antimycobacterial activity is needed. Furthermore, the effects of medicinal plants on macrophagic autophagy response to mycobacterial infection need to be clarified. We herein examined the significance of autophagic events in the manifestation of host immunity during mycobacterial infection, by performing a literature search using PubMed. Recent studies demonstrated that autophagy up-regulated macrophage functions related to the intracellular killing of mycobacteria, even when pathogens were residing within the cytoplasm of macrophages. The majority of medicinal plants potentiated macrophagic autophagy, thereby enhancing their antimycobacterial functions. In contrast, most medicinal plants down-regulate the development and activation of the Th17 cell population, which reduces macrophage antimycobacterial activity. These opposing effects of medicinal plants on macrophage autophagy (enhancement) and Th17 cell functions (inhibition) may provide a plausible explanation for the clinical observation of their modest efficacy in the treatment of mycobacterial infections.
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Affiliation(s)
- Yutaka Tatano
- 1Department of Pharmaceutical Sciences, International University of Health and Welfare, Fukuoka, Japan
| | - Toshiaki Shimizu
- 2Department of Nutrition Administration, Yasuda Women's University, Hiroshima, Japan
| | - Chiaki Sano
- 3Department of Community Medicine Management, Faculty of Medicine, Shimane University, Izumo Japan
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Sengupta S, Pattanaik KP, Mishra S, Sonawane A. Epigenetic orchestration of host immune defences by Mycobacterium tuberculosis. Microbiol Res 2023; 273:127400. [PMID: 37196490 DOI: 10.1016/j.micres.2023.127400] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 04/09/2023] [Accepted: 05/02/2023] [Indexed: 05/19/2023]
Abstract
Being among the top 10 causes of adult deaths, tuberculosis (TB) disease is considered a major global public health concern to address. The human tuberculosis pathogen, Mycobacterium tuberculosis (Mtb), is an extremely competent and well-versed pathogen that promotes pathogenesis by evading the host immune systems through numerous tactics. Investigations revealed that Mtb could evade the host defense mechanisms by reconfiguring the host gene transcription and causing epigenetic changes. Although results indicate the link between epigenetics and disease manifestation in other bacterial infections, little is known regarding the kinetics of the epigenetic alterations in mycobacterial infection. This literature review discusses the studies in Mtb-induced epigenetic alterations inside the host and its contribution in the host immune evasion strategies. It also discusses how the Mtb-induced alterations could be used as 'epibiomarkers' to diagnose TB. Additionally, this review also discusses therapeutic interventions to be enhanced through remodification by 'epidrugs'.
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Affiliation(s)
- Srabasti Sengupta
- School of Biotechnology, Campus-11, KIIT Deemed to be University, Patia, Bhubaneswar 751024, India
| | - Kali Prasad Pattanaik
- School of Biotechnology, Campus-11, KIIT Deemed to be University, Patia, Bhubaneswar 751024, India
| | - Snehasish Mishra
- School of Biotechnology, Campus-11, KIIT Deemed to be University, Patia, Bhubaneswar 751024, India
| | - Avinash Sonawane
- Discipline of Biosciences and Biomedical Engineering, Indian Institutes of Technology Indore, Khandwa Road, Simrol, Indore 453552, India.
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Okugbeni N, du Toit A, Cole-Holman V, Johnson G, Loos B, Kinnear C. Measurement of Autophagy Activity Reveals Time-Dependent, Bacteria-Specific Turnover during Mycobacterium tuberculosis Infection. Pathogens 2022; 12:pathogens12010024. [PMID: 36678372 PMCID: PMC9864524 DOI: 10.3390/pathogens12010024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 12/28/2022] Open
Abstract
The intracellular pathogen, Mycobacterium tuberculosis (M. tb) uses various mechanisms to evade its killing. One of such is phagosomal damage and cytosolic translocation which is then targeted by the host's bactericidal autophagy pathway. It is suggested that cytosolic translocation of M. tb is time-dependent, occurring at later time points of 48 to 72 h post-infection. It is, however, not known whether increased autophagic targeting correlates with these time points of infection. We investigated the time-dependent profile of autophagy activity through the course of M. tb infection in mammalian macrophages. Autophagy activity was inferred by the turnover measurement of autophagy markers and M. tb bacilli in THP-1 and RAW 264.7 macrophages. Over a period of 4 to 72 h, we observed highest autophagy turnover at 48 h of infection in M. tb-containing cells. This was evident by the highest turnover levels of p62 and intracellular M. tb. This supports observations of phagosomal damage mostly occurring at this time point and reveal the correlation of increased autophagy activity. The findings support the preservation of autophagy activity despite M. tb infection while also highlighting time-dependent differences in M. tb-infected macrophages. Future studies may explore time-dependent exogenous autophagy targeting towards host-directed anti-tuberculosis therapy.
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Affiliation(s)
- Naomi Okugbeni
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, US/SAMRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg 7505, South Africa
- South African Medical Research Council Genomics Centre, Tygerberg 7505, South Africa
| | - André du Toit
- Neuro Research Group, Department of Physiological Sciences, Faculty of Sciences, Stellenbosch University, Stellenbosch 7602, South Africa
| | - Victoria Cole-Holman
- South African Medical Research Council Genomics Centre, Tygerberg 7505, South Africa
| | - Glynis Johnson
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, US/SAMRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg 7505, South Africa
| | - Ben Loos
- Neuro Research Group, Department of Physiological Sciences, Faculty of Sciences, Stellenbosch University, Stellenbosch 7602, South Africa
| | - Craig Kinnear
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, US/SAMRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg 7505, South Africa
- South African Medical Research Council Genomics Centre, Tygerberg 7505, South Africa
- Correspondence:
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Nisa A, Kipper FC, Panigrahy D, Tiwari S, Kupz A, Subbian S. Different modalities of host cell death and their impact on Mycobacterium tuberculosis infection. Am J Physiol Cell Physiol 2022; 323:C1444-C1474. [PMID: 36189975 PMCID: PMC9662802 DOI: 10.1152/ajpcell.00246.2022] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 09/16/2022] [Accepted: 09/25/2022] [Indexed: 11/22/2022]
Abstract
Mycobacterium tuberculosis (Mtb) is the pathogen that causes tuberculosis (TB), a leading infectious disease of humans worldwide. One of the main histopathological hallmarks of TB is the formation of granulomas comprised of elaborately organized aggregates of immune cells containing the pathogen. Dissemination of Mtb from infected cells in the granulomas due to host and mycobacterial factors induces multiple cell death modalities in infected cells. Based on molecular mechanism, morphological characteristics, and signal dependency, there are two main categories of cell death: programmed and nonprogrammed. Programmed cell death (PCD), such as apoptosis and autophagy, is associated with a protective response to Mtb by keeping the bacteria encased within dead macrophages that can be readily phagocytosed by arriving in uninfected or neighboring cells. In contrast, non-PCD necrotic cell death favors the pathogen, resulting in bacterial release into the extracellular environment. Multiple types of cell death in the PCD category, including pyroptosis, necroptosis, ferroptosis, ETosis, parthanatos, and PANoptosis, may be involved in Mtb infection. Since PCD pathways are essential for host immunity to Mtb, therapeutic compounds targeting cell death signaling pathways have been experimentally tested for TB treatment. This review summarizes different modalities of Mtb-mediated host cell deaths, the molecular mechanisms underpinning host cell death during Mtb infection, and its potential implications for host immunity. In addition, targeting host cell death pathways as potential therapeutic and preventive approaches against Mtb infection is also discussed.
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Affiliation(s)
- Annuurun Nisa
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Franciele C Kipper
- Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
- Cancer Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Dipak Panigrahy
- Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
- Cancer Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Sangeeta Tiwari
- Department of Biological Sciences, Border Biomedical Research Center (BBRC), University of Texas, El Paso, Texas
| | - Andreas Kupz
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine (AITHM), James Cook University, Townsville, Queensland, Australia
| | - Selvakumar Subbian
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, New Jersey
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Wang J, Sha J, Strong E, Chopra AK, Lee S. FDA-Approved Amoxapine Effectively Promotes Macrophage Control of Mycobacteria by Inducing Autophagy. Microbiol Spectr 2022; 10:e0250922. [PMID: 36129262 PMCID: PMC9602717 DOI: 10.1128/spectrum.02509-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 09/03/2022] [Indexed: 01/04/2023] Open
Abstract
Antibiotic resistance poses a significant hurdle in combating global public health crises, prompting the development of novel therapeutics. Strategies to enhance the intracellular killing of mycobacteria by targeting host defense mechanisms offer numerous beneficial effects, which include reducing cytotoxicity caused by current lengthy anti-tubercular treatment regimens and slowing or circumventing the development of multidrug-resistant strains. The intracellular pathogen Mycobacterium tuberculosis infects macrophages and exploits host machinery to survive and multiply. Using a cell-based screen of FDA-approved drugs, we identified an antidepressant, Amoxapine, capable of inhibiting macrophage cytotoxicity during mycobacterial infection. Notably, this reduced cytotoxicity was related to the enhanced intracellular killing of Mycobacterium bovis BCG and M. tuberculosis within human and murine macrophages. Interestingly, we discovered that postinfection treatment with Amoxapine inhibited mTOR (mammalian target of rapamycin) activation, resulting in the induction of autophagy without affecting autophagic flux in macrophages. Also, inhibition of autophagy by chemical inhibitor 3-MA or knockdown of an essential component of the autophagic pathway, ATG16L1, significantly diminished Amoxapine's intracellular killing effects against mycobacteria in the host cells. Finally, we demonstrated that Amoxapine treatment enhanced host defense against M. tuberculosis in mice. In conclusion, our study identified Amoxapine as a novel host-directed drug that enhances the intracellular killing of mycobacteria by induction of autophagy, with concomitant protection of macrophages against death. IMPORTANCE The emergence and spread of multidrug-resistant (MDR) and extensive drug-resistant (XDR) TB urges the development of new therapeutics. One promising approach to combat drug resistance is targeting host factors necessary for the bacteria to survive or replicate while simultaneously minimizing the dosage of traditional agents. Moreover, repurposing FDA-approved drugs presents an attractive avenue for reducing the cost and time associated with new drug development. Using a cell-based screen of FDA-approved host-directed therapies (HDTs), we showed that Amoxapine inhibits macrophage cytotoxicity during mycobacterial infection and enhances the intracellular killing of mycobacteria within macrophages by activating the autophagy pathway, both in vitro and in vivo. These findings confirm targeted autophagy as an effective strategy for developing new HDT against mycobacteria.
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Affiliation(s)
- Jia Wang
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Jian Sha
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Emily Strong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Ashok K. Chopra
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Sunhee Lee
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
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Gonzalez-Orozco M, Strong EJ, Paroha R, Lee S. Reversing BCG-mediated autophagy inhibition and mycobacterial survival to improve vaccine efficacy. BMC Immunol 2022; 23:43. [PMID: 36104771 PMCID: PMC9472362 DOI: 10.1186/s12865-022-00518-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 08/31/2022] [Indexed: 01/18/2023] Open
Abstract
Background Autophagy is an important mechanism for promoting Mycobacterium clearance from macrophages. Pathogenic and non-pathogenic mycobacterium can activate the mTOR pathway while simultaneously inducing autophagy. M. tuberculosis and M. bovis BCG inhibit autophagy and favor intracellular bacteria survival. Results We observed that pre-infection of live or heat-killed BCG could prevent autophagy induced by pharmacological activators or M. smegmatis, a strong autophagy-inducing mycobacterium. BCG-derived lipids are responsible for autophagy inhibition. However, post-infection with BCG could not stop the autophagy initiated by M. smegmatis, which increases further autophagy induction and mycobacteria clearance. Coinfection with BCG and heat killed M. smegmatis enhanced antigen specific CD4+ T cell responses and reduced mycobacterial survival. Conclusion These results suggest that autophagy-inducing M. smegmatis could be used to promote better innate and consequential adaptive immune responses, improving BCG vaccine efficacy. Supplementary Information The online version contains supplementary material available at 10.1186/s12865-022-00518-z.
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Mycobacterium tuberculosis PPE51 Inhibits Autophagy by Suppressing Toll-Like Receptor 2-Dependent Signaling. mBio 2022; 13:e0297421. [PMID: 35467412 PMCID: PMC9239179 DOI: 10.1128/mbio.02974-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Autophagy is an ubiquitous homeostatic pathway in mammalian cells and plays a significant role in host immunity. Substantial evidence indicates that the ability of Mycobacterium tuberculosis (Mtb) to successfully evade immune responses is partially due to inhibition of autophagic pathways. Our previous screening of Mtb transposon mutants identified the PPE51 protein as an important autophagy-inhibiting effector. We found that expression of PPE51, either by infecting bacteria or by direct expression in host cells, suppressed responses to potent autophagy-inducing stimuli and interfered with bacterial phagocytosis. This phenotype was associated with reduced activation of extracellular signal-regulated kinase 1/2 (ERK1/2), a key component of signaling pathways that stimulate autophagy. Multiple lines of evidence demonstrated that the effects of PPE51 are attributable to signal blocking by Toll-like receptor 2 (TLR2), a receptor with known involvement of activation of ERK1/2 and autophagy. Consistent with these results, mice with intact TLR2 signaling showed striking virulence attenuation for an Mtb ppe51 deletion mutant (Δ51) compared to wild-type Mtb, whereas infection of TLR2-deficient mice showed no such attenuation. Mice infected with Δ51 also displayed increased T cell responses to Mtb antigens and increased autophagy in infected lung tissues. Together, these results suggest that TLR2 activates relevant host immune functions during mycobacterial infection, which Mtb then evades through suppression of TLR2 signaling by PPE51. In addition to its previously identified function transporting substrates across the bacterial cell wall, our results demonstrate a direct role of PPE51 for evasion of both innate and adaptive immunity to Mtb.
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Strong E, Hart B, Wang J, Orozco MG, Lee S. Induced Synthesis of Mycolactone Restores the Pathogenesis of Mycobacterium ulcerans In Vitro and In Vivo. Front Immunol 2022; 13:750643. [PMID: 35401531 PMCID: PMC8988146 DOI: 10.3389/fimmu.2022.750643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 02/22/2022] [Indexed: 11/18/2022] Open
Abstract
Mycobacterium ulcerans is the causative agent of Buruli ulcer (BU), the third most common mycobacterial infection. Virulent M. ulcerans secretes mycolactone, a polyketide toxin. Most observations of M. ulcerans infection are described as an extracellular milieu in the form of a necrotic ulcer. While some evidence exists of an intracellular life cycle for M. ulcerans during infection, the exact role that mycolactone plays in this process is poorly understood. Many previous studies have relied upon the addition of purified mycolactone to cell-culture systems to study its role in M. ulcerans pathogenesis and host-response modulation. However, this sterile system drastically simplifies the M. ulcerans infection model and assumes that mycolactone is the only relevant virulence factor expressed by M. ulcerans. Here we show that the addition of purified mycolactone to macrophages during M. ulcerans infection overcomes the bacterial activation of the mechanistic target of rapamycin (mTOR) signaling pathway that plays a substantial role in regulating different cellular processes, including autophagy and apoptosis. To further study the role of mycolactone during M. ulcerans infection, we have developed an inducible mycolactone expression system. Utilizing the mycolactone-deficient Mul::Tn118 strain that contains a transposon insertion in the putative beta-ketoacyl transferase (mup045), we have successfully restored mycolactone production by expressing mup045 in a tetracycline-inducible vector system, which overcomes in-vitro growth defects associated with constitutive complementation. The inducible mycolactone-expressing bacteria resulted in the establishment of infection in a murine footpad model of BU similar to that observed during the infection with wild-type M. ulcerans. This mycolactone inducible system will allow for further analysis of the roles and functions of mycolactone during M. ulcerans infection.
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Affiliation(s)
- Emily Strong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Bryan Hart
- Human Vaccine Institute, Duke University, Durham, NC, United States
| | - Jia Wang
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Maria Gonzalez Orozco
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Sunhee Lee
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
- Human Vaccine Institute, Duke University, Durham, NC, United States
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, United States
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Baindara P, Agrawal S, Franco OL. Host-directed therapies for malaria and tuberculosis: common infection strategies and repurposed drugs. Expert Rev Anti Infect Ther 2022; 20:849-869. [DOI: 10.1080/14787210.2022.2044794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Piyush Baindara
- Department of Molecular Microbiology & Immunology, School of Medicine, University of Missouri, Missouri, Columbia, MO, USA
| | - Sonali Agrawal
- Immunology Division, ICMR-National JALMA Institute for Leprosy and Other Mycobacterial Diseases, Agra, Uttar Pradesh, India
| | - O. L. Franco
- Proteomics Analysis and Biochemical Center, Catholic University of Brasilia, Brasilia, Brazil; S-Inova Biotech, Catholic University Dom Bosco, Campo Grande, MS, Brazil
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13
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Park EJ, Silwal P, Jo EK. Host-Pathogen Interactions Operative during Mycobacteroides abscessus Infection. Immune Netw 2022; 21:e40. [PMID: 35036027 PMCID: PMC8733189 DOI: 10.4110/in.2021.21.e40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 12/01/2021] [Accepted: 12/09/2021] [Indexed: 12/01/2022] Open
Abstract
Mycobacteroides abscessus (previously Mycobacterium abscessus; Mabc), one of rapidly growing nontuberculous mycobacteria (NTM), is an important pathogen of NTM pulmonary diseases (NTM-PDs) in both immunocompetent and immunocompromised individuals. Mabc infection is chronic and often challenging to treat due to drug resistance, motivating the development of new therapeutics. Despite this, there is a lack of understanding of the relationship between Mabc and the immune system. This review highlights recent progress in the molecular architecture of Mabc and host interactions. We discuss several microbial components that take advantage of host immune defenses, host defense pathways that can overcome Mabc pathogenesis, and how host-pathogen interactions determine the outcomes of Mabc infection. Understanding the molecular mechanisms underlying host-pathogen interactions during Mabc infection will enable the identification of biomarkers and/or drugs to control immune pathogenesis and protect against NTM infection.
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Affiliation(s)
- Eun-Jin Park
- Department of Microbiology, Chungnam National University College of Medicine, Daejeon 35015, Korea.,Infection Control Convergence Research Center, Chungnam National University College of Medicine, Daejeon 35015, Korea
| | - Prashanta Silwal
- Department of Microbiology, Chungnam National University College of Medicine, Daejeon 35015, Korea.,Infection Control Convergence Research Center, Chungnam National University College of Medicine, Daejeon 35015, Korea
| | - Eun-Kyeong Jo
- Department of Microbiology, Chungnam National University College of Medicine, Daejeon 35015, Korea.,Infection Control Convergence Research Center, Chungnam National University College of Medicine, Daejeon 35015, Korea
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14
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Silwal P, Kim IS, Jo EK. Autophagy and Host Defense in Nontuberculous Mycobacterial Infection. Front Immunol 2021; 12:728742. [PMID: 34552591 PMCID: PMC8450401 DOI: 10.3389/fimmu.2021.728742] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/16/2021] [Indexed: 12/12/2022] Open
Abstract
Autophagy is critically involved in host defense pathways through targeting and elimination of numerous pathogens via autophagic machinery. Nontuberculous mycobacteria (NTMs) are ubiquitous microbes, have become increasingly prevalent, and are emerging as clinically important strains due to drug-resistant issues. Compared to Mycobacterium tuberculosis (Mtb), the causal pathogen for human tuberculosis, the roles of autophagy remain largely uncharacterized in the context of a variety of NTM infections. Compelling evidence suggests that host autophagy activation plays an essential role in the enhancement of antimicrobial immune responses and controlling pathological inflammation against various NTM infections. As similar to Mtb, it is believed that NTM bacteria evolve multiple strategies to manipulate and hijack host autophagy pathways. Despite this, we are just beginning to understand the molecular mechanisms underlying the crosstalk between pathogen and the host autophagy system in a battle with NTM bacteria. In this review, we will explore the function of autophagy, which is involved in shaping host–pathogen interaction and disease outcomes during NTM infections. These efforts will lead to the development of autophagy-based host-directed therapeutics against NTM infection.
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Affiliation(s)
- Prashanta Silwal
- Department of Microbiology, Chungnam National University College of Medicine, Daejeon, South Korea.,Infection Control Convergence Research Center, Chungnam National University College of Medicine, Daejeon, South Korea
| | - In Soo Kim
- Department of Microbiology, Chungnam National University College of Medicine, Daejeon, South Korea.,Infection Control Convergence Research Center, Chungnam National University College of Medicine, Daejeon, South Korea
| | - Eun-Kyeong Jo
- Department of Microbiology, Chungnam National University College of Medicine, Daejeon, South Korea.,Infection Control Convergence Research Center, Chungnam National University College of Medicine, Daejeon, South Korea
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15
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Kotze LA, Leukes VN, Fang Z, Lutz MB, Fitzgerald BL, Belisle J, Loxton AG, Walzl G, du Plessis N. Evaluation of autophagy mediators in myeloid-derived suppressor cells during human tuberculosis. Cell Immunol 2021; 369:104426. [PMID: 34469846 DOI: 10.1016/j.cellimm.2021.104426] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 08/18/2021] [Accepted: 08/18/2021] [Indexed: 12/15/2022]
Abstract
Myeloid-derived suppressor cells (MDSC) are induced during active TB disease to restore immune homeostasis but instead exacerbate disease outcome due to chronic inflammation. Autophagy, in conventional phagocytes, ensures successful clearance of M.tb. However, autophagy has been demonstrated to induce prolonged MDSC survival. Here we investigate the relationship between autophagy mediators and MDSC in the context of active TB disease and during anti-TB therapy. We demonstrate a significant increase in MDSC frequencies in untreated active TB cases with these MDSC expressing TLR4 and significantly more mTOR and IL-6 than healthy controls, with mTOR levels decreasing during anti-TB therapy. Finally, we show that HMGB1 serum concentrations decrease in parallel with mTOR. These findings suggest a complex interplay between MDSC and autophagic mediators, potentially dependent on cellular localisation and M.tb infection state.
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Affiliation(s)
- Leigh A Kotze
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Vinzeigh N Leukes
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Zhuo Fang
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Manfred B Lutz
- Institute of Virology and Immunobiology, University of Würzburg, Würzburg, Germany
| | - Bryna L Fitzgerald
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, USA
| | - John Belisle
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, USA
| | - Andre G Loxton
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Gerhard Walzl
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Nelita du Plessis
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Cape Town, South Africa.
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16
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Abstract
Autophagy is a fundamental cellular process that has important roles in innate and adaptive immunity against a broad range of microbes. Many pathogenic microbes have evolved mechanisms to evade or exploit autophagy. It has been previously demonstrated that induction of autophagy can suppress the intracellular survival of mycobacteria, and several PE_PGRS family proteins of Mycobacterium tuberculosis have been proposed to act as inhibitors of autophagy to promote mycobacterial survival. However, the mechanisms by which these effectors inhibit autophagy have not been defined. Here, we report detailed studies of M. tuberculosis deletion mutants of two genes, pe_pgrs20 and pe_pgrs47, that we previously reported as having a role in preventing autophagy of infected host cells. These mutants resulted in increased autophagy and reduced intracellular survival of M. tuberculosis in macrophages. This phenotype was accompanied by increased cytokine production and antigen presentation by infected cells. We further demonstrated that autophagy inhibition by PE_PGRS20 and PE_PGRS47 resulted from canonical autophagy rather than autophagy flux inhibition. Using macrophages transfected to express PE_PGRS20 or PE_PGRS47, we showed that these proteins inhibited autophagy initiation directly by interacting with Ras-related protein Rab1A. Silencing of Rab1A in mammalian cells rescued the survival defects of the pe_pgrs20 and pe_pgrs47 deletion mutant strains and reduced cytokine secretion. To our knowledge, this is the first study to identify mycobacterial effectors that directly interact with host proteins responsible for autophagy initiation. IMPORTANCE Tuberculosis is a significant global infectious disease caused by infection of the lungs with Mycobacterium tuberculosis, which then resides and replicates mainly within host phagocytic cells. Autophagy is a complex host cellular process that helps control intracellular infections and enhance innate and adaptive immune responses. During coevolution with humans, M. tuberculosis has acquired various mechanisms to inhibit host cellular processes, including autophagy. We identified two related M. tuberculosis proteins, PE_PGRS20 and PE_PGRS47, as the first reported examples of specific mycobacterial effectors interfering with the initiation stage of autophagy. Autophagy regulation by these PE_PGRS proteins leads to increased bacterial survival in phagocytic cells and increased autophagic degradation of mycobacterial antigens to stimulate adaptive immune responses. A better understanding of how M. tuberculosis regulates autophagy in host cells could facilitate the design of new and more effective therapeutics or vaccines against tuberculosis.
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17
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Adikesavalu H, Gopalaswamy R, Kumar A, Ranganathan UD, Shanmugam S. Autophagy Induction as a Host-Directed Therapeutic Strategy against Mycobacterium tuberculosis Infection. MEDICINA (KAUNAS, LITHUANIA) 2021; 57:522. [PMID: 34070995 PMCID: PMC8224563 DOI: 10.3390/medicina57060522] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 05/15/2021] [Accepted: 05/21/2021] [Indexed: 12/11/2022]
Abstract
Tuberculosis (TB), a bacterialinfectious disease caused by Mycobacterium tuberculosis (M.tb), which causes significant mortality in humans worldwide. Current treatment regimen involve the administration of multiple antibiotics over the course of several months that contributes to patient non-compliance leading to relapse and the development of drug-resistant M.tb (MDR and XDR) strains. Together, these facts highlight the need for the development of shorter TB treatment regimens. Host-directed therapy (HDT) is a new and emerging concept that aims to augment host immune response using drugs/compounds with or without adjunct antibiotics against M.tb infection. Autophagy is a natural catabolic mechanism of the cell that involves delivering the cytosolic constituents to the lysosomes for degradation and recycling the components; thereby maintaining the cellular and energy homoeostasis of a cell. However, over the past decade, an improved understanding of the role of autophagy in immunity has led to autophagy activation by using drugs or agents. This autophagy manipulation may represent a promising host-directed therapeutic strategy for human TB. However, current clinical knowledge on implementing autophagy activation by drugs or agents, as a stand-alone HDT or as an adjunct with antibiotics to treat human TB is insufficient. In recent years, many reports on high-throughput drug screening and measurement of autophagic flux by fluorescence, high-content microscopy, flow cytometry, microplate reader and immunoblotting have been published for the discovery of drugs that modulate autophagy. In this review, we discuss the commonly used chemical screening approaches in mammalian cells for the discovery of autophagy activating drugs against M.tbinfection. We also summarize the various autophagy-activating agents, both pre-clinical candidates and compounds approved for advanced clinical investigation during mycobacterial infection. Finally, we discuss the opportunities and challenges in using autophagy activation as HDT strategy to improve TB outcome and shorten treatment regimen.
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Affiliation(s)
- Harresh Adikesavalu
- Department of Bacteriology, ICMR-National Institute for Research in Tuberculosis, Chetpet, Chennai 600031, India; (H.A.); (R.G.); (A.K.)
| | - Radha Gopalaswamy
- Department of Bacteriology, ICMR-National Institute for Research in Tuberculosis, Chetpet, Chennai 600031, India; (H.A.); (R.G.); (A.K.)
| | - Ashok Kumar
- Department of Bacteriology, ICMR-National Institute for Research in Tuberculosis, Chetpet, Chennai 600031, India; (H.A.); (R.G.); (A.K.)
| | - Uma Devi Ranganathan
- Department of Immunology, ICMR-National Institute for Research in Tuberculosis, Chetpet, Chennai 600031, India;
| | - Sivakumar Shanmugam
- Department of Bacteriology, ICMR-National Institute for Research in Tuberculosis, Chetpet, Chennai 600031, India; (H.A.); (R.G.); (A.K.)
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18
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Bechelli J, Rumfield CS, Walker DH, Widen S, Khanipov K, Fang R. Subversion of Host Innate Immunity by Rickettsia australis via a Modified Autophagic Response in Macrophages. Front Immunol 2021; 12:638469. [PMID: 33912163 PMCID: PMC8071864 DOI: 10.3389/fimmu.2021.638469] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 03/11/2021] [Indexed: 11/13/2022] Open
Abstract
We recently reported that the in vitro and in vivo survivals of Rickettsia australis are Atg5-dependent, in association with an inhibited level of anti-rickettsial cytokine, IL-1β. In the present study, we sought to investigate how R. australis interacts with host innate immunity via an Atg5-dependent autophagic response. We found that the serum levels of IFN-γ and G-CSF in R. australis-infected Atg5flox/floxLyz-Cre mice were significantly less compared to Atg5flox/flox mice, accompanied by significantly lower rickettsial loads in tissues with inflammatory cellular infiltrations including neutrophils. R. australis infection differentially regulated a significant number of genes in bone marrow-derived macrophages (BMMs) in an Atg5-depdent fashion as determined by RNA sequencing and Ingenuity Pathway Analysis, including genes in the molecular networks of IL-1 family cytokines and PI3K-Akt-mTOR. The secretion levels of inflammatory cytokines, such as IL-1α, IL-18, TNF-α, and IL-6, by R. australis-infected Atg5flox/floxLyz-Cre BMMs were significantly greater compared to infected Atg5flox/flox BMMs. Interestingly, R. australis significantly increased the levels of phosphorylated mTOR and P70S6K at a time when the autophagic response is induced. Rapamycin treatment nearly abolished the phosphorylated mTOR and P70S6K but did not promote significant autophagic flux during R. australis infection. These results highlight that R. australis modulates an Atg5-dependent autophagic response, which is not sensitive to regulation by mTORC1 signaling in macrophages. Overall, we demonstrate that R. australis counteracts host innate immunity including IL-1β-dependent inflammatory response to support the bacterial survival via an mTORC1-resistant autophagic response in macrophages.
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Affiliation(s)
- Jeremy Bechelli
- Department of Pathology, University of Texas Medical Branch at Galveston, Galveston, TX, United States.,Department of Biological Sciences, Sam Houston State University, Huntsville, TX, United States
| | - Claire S Rumfield
- Department of Pathology, University of Texas Medical Branch at Galveston, Galveston, TX, United States.,Laboratory of Tumor Immunology and Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - David H Walker
- Department of Pathology, University of Texas Medical Branch at Galveston, Galveston, TX, United States.,Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX, United States
| | - Steven Widen
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch at Galveston, Galveston, TX, United States
| | - Kamil Khanipov
- Department of Pharmacology and Toxicology, University of Texas Medical Branch at Galveston, Galveston, TX, United States
| | - Rong Fang
- Department of Pathology, University of Texas Medical Branch at Galveston, Galveston, TX, United States.,Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX, United States
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19
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Strong EJ, Lee S. Targeting Autophagy as a Strategy for Developing New Vaccines and Host-Directed Therapeutics Against Mycobacteria. Front Microbiol 2021; 11:614313. [PMID: 33519771 PMCID: PMC7840607 DOI: 10.3389/fmicb.2020.614313] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 12/21/2020] [Indexed: 12/16/2022] Open
Abstract
Mycobacterial disease is an immense burden worldwide. This disease group includes tuberculosis, leprosy (Hansen's disease), Buruli Ulcer, and non-tuberculous mycobacterial (NTM) disease. The burden of NTM disease, both pulmonary and ulcerative, is drastically escalating globally, especially in developed countries such as America and Australia. Mycobacteria's ability to inhibit or evade the host immune system has contributed significantly to its continued prevalence. Pre-clinical studies have highlighted promising candidates that enhance endogenous pathways and/or limit destructive host responses. Autophagy is a cell-autonomous host defense mechanism by which intracytoplasmic cargos can be delivered and then destroyed in lysosomes. Previous studies have reported that autophagy-activating agents, small molecules, and autophagy-activating vaccines may be beneficial in restricting intracellular mycobacterial infection, even with multidrug-resistant strains. This review will examine how mycobacteria evade autophagy and discusses how autophagy could be exploited to design novel TB treatment strategies, such as host-directed therapeutics and vaccines, against Mycobacterium tuberculosis and NTMs.
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Affiliation(s)
| | - Sunhee Lee
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
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20
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Strong EJ, Jurcic Smith KL, Saini NK, Ng TW, Porcelli SA, Lee S. Identification of Autophagy-Inhibiting Factors of Mycobacterium tuberculosis by High-Throughput Loss-of-Function Screening. Infect Immun 2020; 88:e00269-20. [PMID: 32989037 PMCID: PMC7671894 DOI: 10.1128/iai.00269-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 09/23/2020] [Indexed: 12/19/2022] Open
Abstract
The interaction of host cells with mycobacteria is complex and can lead to multiple outcomes ranging from bacterial clearance to progressive or latent infection. Autophagy is recognized as one component of host cell responses that has an essential role in innate and adaptive immunity to intracellular bacteria. Many microbes, including Mycobacterium tuberculosis, have evolved to evade or exploit autophagy, but the precise mechanisms and virulence factors are mostly unknown. Through a loss-of-function screening of an M. tuberculosis transposon mutant library, we identified 16 genes that contribute to autophagy inhibition, six of which encoded the PE/PPE protein family. Their expression in Mycobacterium smegmatis confirmed that these PE/PPE proteins inhibit autophagy and increase intracellular bacterial persistence or replication in infected cells. These effects were associated with increased mammalian target of rapamycin (mTOR) activity and also with decreased production of tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β). We also confirmed that the targeted deletion of the pe/ppe genes in M. tuberculosis resulted in enhanced autophagy and improved intracellular survival rates compared to those of wild-type bacteria in the infected macrophages. Differential expression of these PE/PPE proteins was observed in response to various stress conditions, suggesting that they may confer advantages to M. tuberculosis by modulating its interactions with host cells under various conditions. Our findings demonstrated that multiple M. tuberculosis PE/PPE proteins are involved in inhibiting autophagy during infection of host phagocytes and may provide strategic targets in developing therapeutics or vaccines against tuberculosis.
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Affiliation(s)
- Emily J Strong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | | | - Neeraj K Saini
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Tony W Ng
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Steven A Porcelli
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Sunhee Lee
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Human Vaccine Institute, Duke University, Durham, North Carolina, USA
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, USA
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21
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Saunders EC, McConville MJ. Immunometabolism of Leishmania granulomas. Immunol Cell Biol 2020; 98:832-844. [PMID: 32780446 DOI: 10.1111/imcb.12394] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/06/2020] [Accepted: 08/06/2020] [Indexed: 12/19/2022]
Abstract
Leishmania are parasitic protists that cause a spectrum of diseases in humans characterized by the formation of granulomatous lesions in the skin or other tissues, such as liver and spleen. The extent to which Leishmania granulomas constrain or promote parasite growth is critically dependent on the host T-helper type 1/T-helper type 2 immune response and the localized functional polarization of infected and noninfected macrophages toward a classically (M1) or alternatively (M2) activated phenotype. Recent studies have shown that metabolic reprograming of M1 and M2 macrophages underpins the capacity of these cells to act as permissive or nonpermissive host reservoirs, respectively. In this review, we highlight the metabolic requirements of Leishmania amastigotes and the evidence that these parasites induce and/or exploit metabolic reprogramming of macrophage metabolism. We also focus on recent studies highlighting the role of key macrophage metabolic signaling pathways, such as mechanistic target of rapamycin, adenosine monophosphate-activated protein kinase and peroxisome proliferator receptor gamma in regulating the pathological progression of Leishmania granulomas. These studies highlight the intimate connectivity between Leishmania and host cell metabolism, the need to investigate these interactions in vivo and the potential to exploit host cell metabolic signaling pathways in developing new host-directed therapies.
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Affiliation(s)
- Eleanor C Saunders
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Malcolm J McConville
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, VIC, 3010, Australia
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22
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Kan LLY, Liu D, Chan BCL, Tsang MSM, Hou T, Leung PC, Lam CWK, Wong CK. The flavonoids of Sophora flavescens exerts anti-inflammatory activity via promoting autophagy of Bacillus Calmette-Guérin-stimulated macrophages. J Leukoc Biol 2020; 108:1615-1629. [PMID: 32794339 DOI: 10.1002/jlb.3ma0720-682rr] [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: 01/30/2020] [Revised: 07/24/2020] [Accepted: 08/04/2020] [Indexed: 11/06/2022] Open
Abstract
Tuberculosis (TB), a highly infectious air-borne disease, has remained a global health problem. Conventional treatment and preventions such as antibiotics and Bacilli Calmette-Guerin (BCG) vaccine can be unreliable. In view of the increasing prevalence of anti-TB drug resistance, adjunctive therapy may be necessary to shorten the recovery time. We have previously shown that flavonoids in the medicinal herb Sophora flavescens exhibit anti-inflammatory and bactericidal activities. The aim of this study was to investigate the molecular and cellular characteristics of flavonoids of S. flavescens (FSF) in BCG-stimulated macrophages for assessing their roles in anti-inflammation and autophagy. Mouse alveolar macrophage (MH-S) cell line and primary mouse peritoneal macrophages were stimulated in vitro with heat-inactivated BCG and treated with FSF, with or without autophagy inhibitor Bafilomycin A1 (BafA1). Gene expression was analyzed using quantitative PCR, and cytokine/chemokine release was analyzed by Milliplex assay and ELISA. Autophagy-related proteins were quantified by Western blot and flow cytometry, and autophagolysosomes were detected using fluorescence microscopy. In both MH-S cell line and mouse peritoneal macrophages stimulated by heat-inactivated BCG, FSF was found to up-regulate autophagy-related proteins microtubule-associated protein 1A/1B-light chain 3 (LC3) and protein 62 (p62), and suppress the induced proinflammatory cytokine TNF-α, CCL5, and IL-6. FSF actively modulates immune processes through suppressing BCG-mediated inflammation by promoting autophagy in MH-S cells and mouse peritoneal macrophages. We suggest that FSF may be useful as an adjunctive therapeutic agent for TB infection by modulating cell survival through autophagy and reducing inflammation.
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Affiliation(s)
- Lea Ling-Yu Kan
- Institute of Chinese Medicine and State Key Laboratory of Research on Bioactivities and Clinical Applications of Medicinal Plants, The Chinese University of Hong Kong, Hong Kong, China
| | - Dehua Liu
- Institute of Chinese Medicine and State Key Laboratory of Research on Bioactivities and Clinical Applications of Medicinal Plants, The Chinese University of Hong Kong, Hong Kong, China
| | - Ben Chung-Lap Chan
- Institute of Chinese Medicine and State Key Laboratory of Research on Bioactivities and Clinical Applications of Medicinal Plants, The Chinese University of Hong Kong, Hong Kong, China
| | - Miranda Sin-Man Tsang
- Institute of Chinese Medicine and State Key Laboratory of Research on Bioactivities and Clinical Applications of Medicinal Plants, The Chinese University of Hong Kong, Hong Kong, China.,Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - Tianheng Hou
- Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - Ping Chung Leung
- Institute of Chinese Medicine and State Key Laboratory of Research on Bioactivities and Clinical Applications of Medicinal Plants, The Chinese University of Hong Kong, Hong Kong, China
| | - Christopher Wai-Kei Lam
- Faculty of Medicine and State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Macau, China
| | - Chun Kwok Wong
- Institute of Chinese Medicine and State Key Laboratory of Research on Bioactivities and Clinical Applications of Medicinal Plants, The Chinese University of Hong Kong, Hong Kong, China.,Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China.,Li Dak Sum Yip Yio Chin R & D Centre for Chinese Medicine, The Chinese University of Hong Kong, Hong Kong, China
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23
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Trained immunity as a molecular mechanism for BCG immunotherapy in bladder cancer. Nat Rev Urol 2020; 17:513-525. [PMID: 32678343 DOI: 10.1038/s41585-020-0346-4] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/03/2020] [Indexed: 01/01/2023]
Abstract
Intravesical BCG instillation is the gold-standard adjuvant immunotherapy for patients with high-risk non-muscle-invasive bladder cancer. However, the precise mechanism of action by which BCG asserts its beneficial effects is still unclear. BCG has been shown to induce a non-specific enhancement of the biological function in cells of the innate immune system, creating a de facto heterologous immunological memory that has been termed trained immunity. Trained immunity or innate immune memory enables innate immune cells to mount a more robust response to secondary non-related stimuli after being initially primed (or trained) by a challenge such as BCG. BCG-induced trained immunity is characterized by the metabolic rewiring of monocyte intracellular metabolism and epigenetic modifications, which subsequently lead to functional reprogramming effects, such as an increased production of cytokines, on restimulation. Results from BCG vaccination studies in humans show that trained immunity might at least partly account for the heterologous beneficial effects of BCG vaccination. Additionally, immunity might have a role in the effect of BCG immunotherapy for bladder cancer. Based on these indications, we propose that trained immunity could be one of the important mechanisms mediating BCG immunotherapy and could provide a basis for further improvements towards a personalized approach to BCG therapy in non-muscle-invasive bladder cancer.
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24
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Shah JA, Lindestam Arlehamn CS, Horne DJ, Sette A, Hawn TR. Nontuberculous Mycobacteria and Heterologous Immunity to Tuberculosis. J Infect Dis 2020; 220:1091-1098. [PMID: 31165861 DOI: 10.1093/infdis/jiz285] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 06/03/2019] [Indexed: 12/25/2022] Open
Abstract
Development of an improved tuberculosis (TB) vaccine is a high worldwide public health priority. Bacillus Calmette-Guerin (BCG), the only licensed TB vaccine, provides variable efficacy against adult pulmonary TB, but why this protection varies is unclear. Humans are regularly exposed to non-tuberculous mycobacteria (NTM) that live in soil and water reservoirs and vary in different geographic regions around the world. Immunologic cross-reactivity may explain disparate outcomes of BCG vaccination and susceptibility to TB disease. Evidence supporting this hypothesis is increasing but challenging to obtain due to a lack of reliable research tools. In this review, we describe the progress and bottlenecks in research on NTM epidemiology, immunology and heterologous immunity to Mtb. With ongoing efforts to develop new vaccines for TB, understanding the effect of NTM on vaccine efficacy may be a critical determinant of success.
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Affiliation(s)
- Javeed A Shah
- Tuberculosis Research and Training Center, Department of Medicine, University of Washington, Seattle.,Veterans Affairs Puget Sound Health Care System, Seattle, Washington
| | | | - David J Horne
- Tuberculosis Research and Training Center, Department of Medicine, University of Washington, Seattle
| | - Alessandro Sette
- Division of Vaccine Discovery, La Jolla Institute for Immunology, California.,University of California San Diego, La Jolla
| | - Thomas R Hawn
- Tuberculosis Research and Training Center, Department of Medicine, University of Washington, Seattle
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25
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Xu J, Zhou Y, Yang Y, Lv C, Liu X, Wang Y. Involvement of ABC-transporters and acyltransferase 1 in intracellular cholesterol-mediated autophagy in bovine alveolar macrophages in response to the Bacillus Calmette-Guerin (BCG) infection. BMC Immunol 2020; 21:26. [PMID: 32397995 PMCID: PMC7216371 DOI: 10.1186/s12865-020-00356-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 05/04/2020] [Indexed: 02/07/2023] Open
Abstract
Background Understanding pathogenic mechanisms is imperative for developing novel treatment to the tuberculosis, an important public health burden worldwide. Recent studies demonstrated that host cholesterol levels have implications in the establishment of Mycobacterium tuberculosis (M. tuberculosis, Mtb) infection in host cells, in which the intracellular cholesterol-mediated ATP-binding cassette transporters (ABC-transporters) and cholesterol acyltransferase1 (ACAT1) exhibited abilities to regulate macrophage autophagy induced by Mycobacterium bovis bacillus Calmette–Guérin (BCG). Results The results showed that a down-regulated expression of the ABC-transporters and ACAT1 in primary bovine alveolar macrophages (AMs) and murine RAW264.7 cells in response to a BCG infection. The inhibited expression of ABC-transporters and ACAT1 was associated with the reduction of intracellular free cholesterol, which in turn induced autophagy in macrophages upon to the Mycobacterial infection. These results strongly suggest an involvement of ABC-transporters and ACAT1 in intracellular cholesterol-mediated autophagy in AMs in response to BCG infection. Conclusion This study thus provides an insight into into a mechanism by which the cholesterol metabolism regulated the autophagy in macrophages in response to mycobacterial infections.
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Affiliation(s)
- Jinrui Xu
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Yinchuan, China.,College of Life Science, Ningxia University, Yinchuan, 750021, Ningxia, China
| | - Yanbing Zhou
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Yinchuan, China.,College of Life Science, Ningxia University, Yinchuan, 750021, Ningxia, China
| | - Yi Yang
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Yinchuan, China.,College of Life Science, Ningxia University, Yinchuan, 750021, Ningxia, China
| | - Cuiping Lv
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Yinchuan, China.,College of Life Science, Ningxia University, Yinchuan, 750021, Ningxia, China
| | - Xiaoming Liu
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Yinchuan, China. .,College of Life Science, Ningxia University, Yinchuan, 750021, Ningxia, China.
| | - Yujiong Wang
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Yinchuan, China. .,College of Life Science, Ningxia University, Yinchuan, 750021, Ningxia, China.
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26
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Dadhich R, Mishra M, Ning S, Jana S, Sarpe VA, Mahato J, Duan M, Kulkarni SS, Kapoor S. A Virulence-Associated Glycolipid with Distinct Conformational Attributes: Impact on Lateral Organization of Host Plasma Membrane, Autophagy, and Signaling. ACS Chem Biol 2020; 15:740-750. [PMID: 32078292 DOI: 10.1021/acschembio.9b00991] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mycobacterium tuberculosis (Mtb) serves as the epitome of how lipids-next to proteins-are utilized as central effectors in pathogenesis. It synthesizes an arsenal of structurally atypical lipids (C60-C90) to impact various membrane-dependent steps involved in host interactions. There is a growing precedent to support insertion of these exposed lipids into the host membrane as part of their mode of action. However, the vital role of specific virulence-associated lipids in modulating cellular functions by altering the host membrane organization and associated signaling pathways remain unanswered questions. Here, we combined chemical synthesis, biophysics, cell biology, and molecular dynamics simulations to elucidate host membrane structure modifications and modulation of membrane-associated signaling using synthetic Mycobacterium tuberculosis sulfoglycolipids (Mtb SL). We reveal that Mtb SL reorganizes the host cell plasma membrane domains while showing higher preference for fluid membrane regions. This rearrangement is governed by the distinct conformational states sampled by SL acyl chains. Physicochemical assays with SL analogues reveal insights into their structure-function relationships, highlighting specific roles of lipid acyl chains and headgroup, along with effects on autophagy and cytokine profiles. Our findings uncover a mechanism whereby Mtb uses specific chemical moieties on its lipids to fine-tune host lipid interactions and confer control of the downstream functions by modifying the cell membrane structure and function. These findings will inspire development of chemotherapeutics against Mtb by counteracting their effects on the host-cell membrane.
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Affiliation(s)
- Ruchika Dadhich
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Manjari Mishra
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Shangbo Ning
- Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Santanu Jana
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Vikram A. Sarpe
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Jaladhar Mahato
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Mojie Duan
- Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Suvarn S. Kulkarni
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Shobhna Kapoor
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
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Bento CM, Gomes MS, Silva T. Looking beyond Typical Treatments for Atypical Mycobacteria. Antibiotics (Basel) 2020; 9:antibiotics9010018. [PMID: 31947883 PMCID: PMC7168257 DOI: 10.3390/antibiotics9010018] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 12/31/2019] [Accepted: 12/31/2019] [Indexed: 12/30/2022] Open
Abstract
The genus Mycobacterium comprises not only the deadliest of bacterial pathogens, Mycobacterium tuberculosis, but several other pathogenic species, including M. avium and M. abscessus. The incidence of infections caused by atypical or nontuberculous mycobacteria (NTM) has been steadily increasing, and is associated with a panoply of diseases, including pulmonary, soft-tissue, or disseminated infections. The treatment for NTM disease is particularly challenging, due to its long duration, to variability in bacterial susceptibility profiles, and to the lack of evidence-based guidelines. Treatment usually consists of a combination of at least three drugs taken from months to years, often leading to severe secondary effects and a high chance of relapse. Therefore, new treatment approaches are clearly needed. In this review, we identify the main limitations of current treatments and discuss different alternatives that have been put forward in recent years, with an emphasis on less conventional therapeutics, such as antimicrobial peptides, bacteriophages, iron chelators, or host-directed therapies. We also review new forms of the use of old drugs, including the repurposing of non-antibacterial molecules and the incorporation of antimicrobials into ionic liquids. We aim to stimulate advancements in testing these therapies in relevant models, in order to provide clinicians and patients with useful new tools with which to treat these devastating diseases.
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Affiliation(s)
- Clara M. Bento
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (C.M.B.); (T.S.)
- IBMC—Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Maria Salomé Gomes
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (C.M.B.); (T.S.)
- IBMC—Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
- ICBAS—Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
- Correspondence:
| | - Tânia Silva
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (C.M.B.); (T.S.)
- IBMC—Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
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28
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Singh B, Saqib M, Chakraborty A, Bhaskar S. Lipoarabinomannan from Mycobacterium indicus pranii shows immunostimulatory activity and induces autophagy in macrophages. PLoS One 2019; 14:e0224239. [PMID: 31648257 PMCID: PMC6812838 DOI: 10.1371/journal.pone.0224239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 10/08/2019] [Indexed: 01/20/2023] Open
Abstract
Mycobacterium indicus pranii (MIP) known for its immunotherapeutic potential against leprosy and tuberculosis is undergoing various clinical trials and also simultaneously being studied in animal models to get insight into the mechanistic details contributing to its protective efficacy as a vaccine candidate. Studies have shown potential immunomodulatory properties of MIP, the most significant being the ability to induce strong Th1 type of response, enhanced expression of pro-inflammatory cytokines, activation of APCs and lymphocytes, elicitation of M.tb specific poly-functional T cells. All of these form crucial components of host-immune response during M.tb infection. Also, MIP was found to be potent inducer of autophagy in macrophages which resulted in enhanced clearance of M.tb from MIP and M.tb co-infected cells. Hence, we further examined the component/s of MIP responsible for autophagy induction. Interestingly, we found that MIP lipids and DNA were able to induce autophagy but not the protein fraction. LAM being one of the crucial components of mycobacterial cell-wall lipids and possessing the ability of immunomodulation; we isolated LAM from MIP and did a comparative study with M.tb-LAM. Stimulation with MIP-LAM resulted in significantly high secretion of pro-inflammatory cytokines and displayed high autophagy inducing potential in macrophages as compared to M.tb-LAM. Treatment with MIP-LAM enhanced the co-localization of M.tb within the phago-lysosomes and increased the clearance of M.tb from the infected macrophages. This study describes LAM to be a crucial component of MIP which has significant contribution to its immunotherapeutic efficacy against TB.
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Affiliation(s)
- Bindu Singh
- Product Development Cell-1, National Institute of Immunology, New Delhi, India
| | - Mohd Saqib
- Product Development Cell-1, National Institute of Immunology, New Delhi, India
| | - Anush Chakraborty
- Product Development Cell-1, National Institute of Immunology, New Delhi, India
| | - Sangeeta Bhaskar
- Product Development Cell-1, National Institute of Immunology, New Delhi, India
- * E-mail:
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29
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Wilson JL, Mayr HK, Weichhart T. Metabolic Programming of Macrophages: Implications in the Pathogenesis of Granulomatous Disease. Front Immunol 2019; 10:2265. [PMID: 31681260 PMCID: PMC6797840 DOI: 10.3389/fimmu.2019.02265] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 09/09/2019] [Indexed: 12/16/2022] Open
Abstract
Metabolic reprogramming is rapidly gaining appreciation in the etiology of immune cell dysfunction in a variety of diseases. Tuberculosis, schistosomiasis, and sarcoidosis represent an important class of diseases characterized by the formation of granulomas, where macrophages are causatively implicated in disease pathogenesis. Recent studies support the incidence of macrophage metabolic reprogramming in granulomas of both infectious and non-infectious origin. These publications identify the mechanistic target of rapamycin (mTOR), as well as the major regulators of lipid metabolism and cellular energy balance, peroxisome proliferator receptor gamma (PPAR-γ) and adenosine monophosphate-activated protein kinase (AMPK), respectively, as key players in the pathological progression of granulomas. In this review, we present a comprehensive breakdown of emerging research on the link between macrophage cell metabolism and granulomas of different etiology, and how parallels can be drawn between different forms of granulomatous disease. In particular, we discuss the role of PPAR-γ signaling and lipid metabolism, which are currently the best-represented metabolic pathways in this context, and we highlight dysregulated lipid metabolism as a common denominator in granulomatous disease progression. This review therefore aims to highlight metabolic mechanisms of granuloma immune cell fate and open up research questions for the identification of potential therapeutic targets in the future.
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Affiliation(s)
- Jayne Louise Wilson
- Center for Pathobiochemistry and Genetics, Institute of Medical Genetics, Medical University of Vienna, Vienna, Austria
| | - Hannah Katharina Mayr
- Center for Pathobiochemistry and Genetics, Institute of Medical Genetics, Medical University of Vienna, Vienna, Austria
| | - Thomas Weichhart
- Center for Pathobiochemistry and Genetics, Institute of Medical Genetics, Medical University of Vienna, Vienna, Austria
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30
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Mishra M, Adhyapak P, Dadhich R, Kapoor S. Dynamic Remodeling of the Host Cell Membrane by Virulent Mycobacterial Sulfoglycolipid-1. Sci Rep 2019; 9:12844. [PMID: 31492926 PMCID: PMC6731295 DOI: 10.1038/s41598-019-49343-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 08/23/2019] [Indexed: 12/31/2022] Open
Abstract
Lipids dictate membrane properties to modulate lateral membrane organization, lipid/protein diffusion and lipid-protein interactions, thereby underpinning proper functioning of cells. Mycobacterium tuberculosis harnesses the power of its atypical cell wall lipids to impact immune surveillance machinery centered at the host cell membrane. However, the role of specific virulent lipids in altering host cellular functions by modulating membrane organization and the associated signaling response are still pertinent unresolved questions. Here, combining membrane biophysics and cell biology, we elucidate how virulent Mtb sulfoglycolipids hijack the host cell membrane, affecting its order, fluidity, and stiffness along with manipulating the linked cytoskeleton. The functional outcome of this perturbation was assayed by monitoring membrane-associated autophagy signaling. These actions form a part of the overall response to commandeer host membrane-associated immune processes during infection. The findings on the mechanism of action of Mtb lipids on host cell membrane structure and downstream signaling will deepen the collective understanding of their functional aspects in membrane-dictated bacterial survival, pathogenesis and drug resistance and reveal suitable membrane driven-therapeutic intervention points and diagnostic tools.
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Affiliation(s)
- Manjari Mishra
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, India
| | - Pranav Adhyapak
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, India
| | - Ruchika Dadhich
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, India
| | - Shobhna Kapoor
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, India.
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31
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Xiong W, Wen Q, Du X, Wang J, He W, Wang R, Hu S, Zhou X, Yang J, Gao Y, Ma L. Novel Function of Cyclooxygenase-2: Suppressing Mycobacteria by Promoting Autophagy via the Protein Kinase B/Mammalian Target of Rapamycin Pathway. J Infect Dis 2019; 217:1267-1279. [PMID: 29373690 DOI: 10.1093/infdis/jiy033] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 01/18/2018] [Indexed: 12/22/2022] Open
Abstract
In Mycobacterium tuberculosis-infected macrophages, cyclooxygenase-2 (COX-2) expression considerably increases to defend the body against mycobacteria by regulating adaptive immunity and restoring the mitochondrial inner membrane. Moreover, in cancer cells, COX-2 enhances the autophagy machinery, an important bactericidal mechanism. However, the association between M. tuberculosis-induced COX-2 and autophagy-mediated antimycobacterial response has not been explored. Here, COX-2 expression silencing reduced the autophagy and bactericidal activity against intracellular M. tuberculosis, while COX-2 overexpression reversed the above effects. In addition, enhancement of bactericidal activity was suppressed by inhibiting autophagy in COX-2-overexpressing cells, indicating that COX-2 accelerated mycobacterial elimination by promoting autophagy. Furthermore, the regulatory effects of COX-2 on autophagy were mediated by its catalytic products, which functioned through inhibiting the protein kinase B/mammalian target of rapamycin pathway. Thus, COX-2 contributes to host defense against mycobacterial infection by promoting autophagy, establishing the basis for development of novel therapeutic agents against tuberculosis by targeting COX-2.
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Affiliation(s)
- Wenjing Xiong
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Qian Wen
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Xialin Du
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Jinli Wang
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Wenting He
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Ruining Wang
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Shengfeng Hu
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Xinying Zhou
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Jiahui Yang
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Yuchi Gao
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Li Ma
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
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32
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Sabir N, Hussain T, Liao Y, Wang J, Song Y, Shahid M, Cheng G, Mangi MH, Yao J, Yang L, Zhao D, Zhou X. Kallikrein 12 Regulates Innate Resistance of Murine Macrophages against Mycobacterium bovis Infection by Modulating Autophagy and Apoptosis. Cells 2019; 8:cells8050415. [PMID: 31060300 PMCID: PMC6562459 DOI: 10.3390/cells8050415] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 04/29/2019] [Accepted: 04/30/2019] [Indexed: 12/27/2022] Open
Abstract
Mycobacterium bovis (M. bovis) is a member of the Mycobacterium tuberculosis (Mtb) complex causing bovine tuberculosis (TB) and imposing a high zoonotic threat to human health. Kallikreins (KLKs) belong to a subgroup of secreted serine proteases. As their role is established in various physiological and pathological processes, it is likely that KLKs expression may mediate a host immune response against the M. bovis infection. In the current study, we report in vivo and in vitro upregulation of KLK12 in the M. bovis infection. To define the role of KLK12 in immune response regulation of murine macrophages, we produced KLK12 knockdown bone marrow derived macrophages (BMDMs) by using siRNA transfection. Interestingly, the knockdown of KLK12 resulted in a significant downregulation of autophagy and apoptosis in M. bovis infected BMDMs. Furthermore, we demonstrated that this KLK12 mediated regulation of autophagy and apoptosis involves mTOR/AMPK/TSC2 and BAX/Bcl-2/Cytochrome c/Caspase 3 pathways, respectively. Similarly, inflammatory cytokines IL-1β, IL-6, IL-12 and TNF-α were significantly downregulated in KLK12 knockdown macrophages but the difference in IL-10 and IFN-β expression was non-significant. Taken together, these findings suggest that upregulation of KLK12 in M. bovis infected murine macrophages plays a substantial role in the protective immune response regulation by modulating autophagy, apoptosis and pro-inflammatory pathways. To our knowledge, this is the first report on expression and the role of KLK12 in the M. bovis infection and the data may contribute to a new paradigm for diagnosis and treatment of bovine TB.
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Affiliation(s)
- Naveed Sabir
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Tariq Hussain
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Yi Liao
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Jie Wang
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Yinjuan Song
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Muhammad Shahid
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Guangyu Cheng
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Mazhar Hussain Mangi
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Jiao Yao
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Lifeng Yang
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Deming Zhao
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Xiangmei Zhou
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
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33
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Wu X, Zhang J, Ma C, Li W, Zeng J, Wang Y, Deng G. A role for Wnt/β-catenin signalling in suppressing Bacillus Calmette-Guerin-induced macrophage autophagy. Microb Pathog 2018; 127:277-287. [PMID: 30550847 DOI: 10.1016/j.micpath.2018.12.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 12/08/2018] [Accepted: 12/10/2018] [Indexed: 12/11/2022]
Abstract
Mycobacterium tuberculosis (Mtb)-induced autophagy of alveolar macrophages has been confirmed to play a central role in the pathogenesis of tuberculosis. Growing evidence indicates that excessive or uncontrolled autophagic activity, which results in type II programmed cell death, can be regulated by many factors, including Wnt/β-catenin signalling. Wnt/β-catenin signalling has been demonstrated to be involved in multiple diseases through the regulation of autophagy; however, its exact role in regulating autophagy induced by Mtb remains unclear. Accordingly, this study examined the function of the Wnt/β-catenin signalling pathway in regulating Mycobacterium bovis Bacillus Calmette-Guerin (BCG)-induced autophagy in RAW264.7 macrophage cell line. In the present study, we found that BCG induced the autophagy of RAW264.7 cells in a time- and dose-dependent manner along with an accumulation of LC3 (Microtubule-associated protein 1 light chain 3) protein. Intriguingly, Wnt3a, a Wnt/β-catenin signalling ligand, significantly inhibited autophagy, with decreased autophagy rates and autophagic flux. An immunoblot analysis further revealed that Wnt/β-catenin signalling was capable of inhibiting the expression of the LC3 and autophagy-associated gene (Atg) cascade proteins in BCG-infected cells. Mechanistically, Wnt/β-catenin signalling may inhibit autophagy in BCG-infected macrophages by activating mTOR-dependent pathways. Our findings reveal the mechanisms of Wnt/β-catenin signalling regulates cellular autophagy induced by Mtb and provide novel insights into physiological and immune control of tuberculosis by modulating autophagy processes.
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Affiliation(s)
- Xiaoling Wu
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western China, Yinchuan, 750021, Ningxia, China; College of Life Science, Ningxia University, Yinchuan, 750021, Ningxia, China
| | - Jiamei Zhang
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western China, Yinchuan, 750021, Ningxia, China; College of Life Science, Ningxia University, Yinchuan, 750021, Ningxia, China
| | - Chenjie Ma
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western China, Yinchuan, 750021, Ningxia, China; College of Life Science, Ningxia University, Yinchuan, 750021, Ningxia, China
| | - Wu Li
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western China, Yinchuan, 750021, Ningxia, China; College of Life Science, Ningxia University, Yinchuan, 750021, Ningxia, China
| | - Jin Zeng
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western China, Yinchuan, 750021, Ningxia, China; College of Life Science, Ningxia University, Yinchuan, 750021, Ningxia, China
| | - Yujiong Wang
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western China, Yinchuan, 750021, Ningxia, China; College of Life Science, Ningxia University, Yinchuan, 750021, Ningxia, China.
| | - Guangcun Deng
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western China, Yinchuan, 750021, Ningxia, China; College of Life Science, Ningxia University, Yinchuan, 750021, Ningxia, China.
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34
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Mohareer K, Asalla S, Banerjee S. Cell death at the cross roads of host-pathogen interaction in Mycobacterium tuberculosis infection. Tuberculosis (Edinb) 2018; 113:99-121. [PMID: 30514519 DOI: 10.1016/j.tube.2018.09.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 07/13/2018] [Accepted: 09/24/2018] [Indexed: 12/21/2022]
Abstract
Tuberculosis (TB) continues to be the leading cause of death by any single infectious agent, accounting for around 1.7 million annual deaths globally, despite several interventions and support programs by national and international agencies. With the development of drug resistance in Mycobacterium tuberculosis (M. tb), there has been a paradigm shift in TB research towards host-directed therapy. The potential targets include the interactions between host and bacterial proteins that are crucial for pathogenesis. Hence, collective efforts are being made to understand the molecular details of host-pathogen interaction for possible translation into host-directed therapy. The present review focuses on 'host cell death modalities' of host-pathogen interaction, which play a crucial role in determining the outcome of TB disease progression. Several cell death modalities that occur in response to mycobacterial infection have been identified in human macrophages either as host defences for bacterial clearance or as pathogen strategies for multiplication and dissemination. These cell death modalities include apoptosis, necrosis, pyroptosis, necroptosis, pyronecrosis, NETosis, and autophagy. These processes are highly overlapping with several mycobacterial proteins participating in more than one cell death pathway. Until now, reviews in M. tb and host cell death have discussed either focusing on host evasion strategies, apoptosis, autophagy, and necrosis or describing all these forms with limited discussions of their role in host-pathogen interactions. Here, we present a comprehensive review of various mycobacterial factors modulating host cell death pathways and the cross-talk between them. Besides this, we have discussed the networking of host cell death pathways including the interference of host miRNA during M. tb infection with their respective targets. Through this review, we present the host targets that overlap across several cell death modalities and the technical limitations of methodology in cell death research. Given the compelling need to discover alternative drug target(s), this review identifies these overlapping cell death factors as potential targets for host-directed therapy.
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Affiliation(s)
- Krishnaveni Mohareer
- Molecular Pathogenesis Laboratory, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, India-500046
| | - Suman Asalla
- Molecular Pathogenesis Laboratory, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, India-500046
| | - Sharmistha Banerjee
- Molecular Pathogenesis Laboratory, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, India-500046.
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Kim SW, Subhadra B, Whang J, Back YW, Bae HS, Kim HJ, Choi CH. Clinical Mycobacterium abscessus strain inhibits autophagy flux and promotes its growth in murine macrophages. Pathog Dis 2018; 75:4259640. [PMID: 29044406 DOI: 10.1093/femspd/ftx107] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 09/25/2017] [Indexed: 02/07/2023] Open
Abstract
Autophagy is known to be a vital homeostatic defense process that controls mycobacterial infection. However, the relationship between autophagy response and the virulence of Mycobacterium abscessus strain UC22 has not been reported. Here, we demonstrate that M. abscessus induces autophagy and inhibits autophagy flux in murine macrophages. Further, the rough variant of M. abscessus, UC22 that is a highly virulent clinical isolate, significantly inhibited autophagic flux than the smooth variant of M. abscessus ATCC 19977. In addition, it was noticed that the intracellular survival of UC22 is significantly enhanced by blocking the autophagosome-lysosome fusion in macrophages compared to the smooth variant. However, Mycobacterium smegmatis did not block autophagy flux in murine macrophages. Besides, we confirmed that the lipid components of M. abscessus UC22 play a role in autophagosome formation. These data suggest that the virulent M. abscessus might be able to survive and grow within autophagosomes by preventing the autophagosome-lysosome fusion and their clearance from the cells.
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Affiliation(s)
- Seong-Woo Kim
- Department of Microbiology and Medical Science, Chungnam National University School of Medicine, 266 Munwha-ro, Jung-gu, Daejeon 35015, Republic of Korea
| | - Bindu Subhadra
- Department of Microbiology and Medical Science, Chungnam National University School of Medicine, 266 Munwha-ro, Jung-gu, Daejeon 35015, Republic of Korea
| | - Jake Whang
- Department of Microbiology and Medical Science, Chungnam National University School of Medicine, 266 Munwha-ro, Jung-gu, Daejeon 35015, Republic of Korea
| | - Yong Woo Back
- Department of Microbiology and Medical Science, Chungnam National University School of Medicine, 266 Munwha-ro, Jung-gu, Daejeon 35015, Republic of Korea
| | - Hyun Shik Bae
- Department of Microbiology and Medical Science, Chungnam National University School of Medicine, 266 Munwha-ro, Jung-gu, Daejeon 35015, Republic of Korea
| | - Hwa-Jung Kim
- Department of Microbiology and Medical Science, Chungnam National University School of Medicine, 266 Munwha-ro, Jung-gu, Daejeon 35015, Republic of Korea
| | - Chul Hee Choi
- Department of Microbiology and Medical Science, Chungnam National University School of Medicine, 266 Munwha-ro, Jung-gu, Daejeon 35015, Republic of Korea
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36
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Sabir N, Hussain T, Shah SZA, Zhao D, Zhou X. IFN-β: A Contentious Player in Host-Pathogen Interaction in Tuberculosis. Int J Mol Sci 2017; 18:ijms18122725. [PMID: 29258190 PMCID: PMC5751326 DOI: 10.3390/ijms18122725] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 12/08/2017] [Accepted: 12/12/2017] [Indexed: 12/03/2022] Open
Abstract
Tuberculosis (TB) is a major health threat to the human population worldwide. The etiology of the disease is Mycobacterium tuberculosis (Mtb), a highly successful intracellular pathogen. It has the ability to manipulate the host immune response and to make the intracellular environment suitable for its survival. Many studies have addressed the interactions between the bacteria and the host immune cells as involving many immune mediators and other cellular players. Interferon-β (IFN-β) signaling is crucial for inducing the host innate immune response and it is an important determinant in the fate of mycobacterial infection. The role of IFN-β in protection against viral infections is well established and has been studied for decades, but its role in mycobacterial infections remains much more complicated and debatable. The involvement of IFN-β in immune evasion mechanisms adopted by Mtb has been an important area of investigation in recent years. These advances have widened our understanding of the pro-bacterial role of IFN-β in host–pathogen interactions. This pro-bacterial activity of IFN-β appears to be correlated with its anti-inflammatory characteristics, primarily by antagonizing the production and function of interleukin 1β (IL-1β) and interleukin 18 (IL-18) through increased interleukin 10 (IL-10) production and by inhibiting the nucleotide-binding domain and leucine-rich repeat protein-3 (NLRP3) inflammasome. Furthermore, it also fails to provoke a proper T helper 1 (Th1) response and reduces the expression of major histocompatibility complex II (MHC-II) and interferon-γ receptors (IFNGRs). Here we will review some studies to provide a paradigm for the induction, regulation, and role of IFN-β in mycobacterial infection. Indeed, recent studies suggest that IFN-β plays a role in Mtb survival in host cells and its downregulation may be a useful therapeutic strategy to control Mtb infection.
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Affiliation(s)
- Naveed Sabir
- State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Tariq Hussain
- State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Syed Zahid Ali Shah
- State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Deming Zhao
- State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Xiangmei Zhou
- State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
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Autophagy induction by Mycobacterium indicus pranii promotes Mycobacterium tuberculosis clearance from RAW 264.7 macrophages. PLoS One 2017; 12:e0189606. [PMID: 29236768 PMCID: PMC5728553 DOI: 10.1371/journal.pone.0189606] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 11/29/2017] [Indexed: 12/11/2022] Open
Abstract
Mycobacterium indicus pranii (MIP) is a potent vaccine candidate against tuberculosis (TB) as it has demonstrated significant protection in animal models of tuberculosis as well as in clinical trials. Higher protective efficacy of MIP against TB as compared to BCG provoked the efforts to gain insight into the molecular mechanisms underlying MIP mediated protection against Mycobacterium tuberculosis (M.tb). Autophagy, initially described as a cell survival mechanism during starvation, also plays a key role in host resistance to M.tb. Virulent mycobacteria like M.tb, suppresses host autophagy response to increase its survival in macrophages. Since mycobacterial species have been shown to vary widely in their autophagy-inducing properties, in the present study, we examined the autophagy inducing efficacy of MIP and its role in MIP-mediated protection against M.tb. MIP was found to be potent inducer of autophagy in macrophages. Induced autophagy was responsible for reversal of the phagosome maturation block and phagolysosome fusion inhibition in M.tb infected macrophages, which ultimately lead to significantly enhanced clearance of M.tb from the macrophages. This is an important study which further delineated the underlying mechanisms for significant immunotherapeutic activity observed in TB patients / animal models of tuberculosis, given MIP therapy along with chemotherapy.
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Roux AL, Viljoen A, Bah A, Simeone R, Bernut A, Laencina L, Deramaudt T, Rottman M, Gaillard JL, Majlessi L, Brosch R, Girard-Misguich F, Vergne I, de Chastellier C, Kremer L, Herrmann JL. The distinct fate of smooth and rough Mycobacterium abscessus variants inside macrophages. Open Biol 2017; 6:rsob.160185. [PMID: 27906132 PMCID: PMC5133439 DOI: 10.1098/rsob.160185] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 10/31/2016] [Indexed: 02/07/2023] Open
Abstract
Mycobacterium abscessus is a pathogenic, rapidly growing mycobacterium responsible for pulmonary and cutaneous infections in immunocompetent patients and in patients with Mendelian disorders, such as cystic fibrosis (CF). Mycobacterium abscessus is known to transition from a smooth (S) morphotype with cell surface-associated glycopeptidolipids (GPL) to a rough (R) morphotype lacking GPL. Herein, we show that M. abscessus S and R variants are able to grow inside macrophages and are present in morphologically distinct phagosomes. The S forms are found mostly as single bacteria within phagosomes characterized by a tightly apposed phagosomal membrane and the presence of an electron translucent zone (ETZ) surrounding the bacilli. By contrast, infection with the R form leads to phagosomes often containing more than two bacilli, surrounded by a loose phagosomal membrane and lacking the ETZ. In contrast to the R variant, the S variant is capable of restricting intraphagosomal acidification and induces less apoptosis and autophagy. Importantly, the membrane of phagosomes enclosing the S forms showed signs of alteration, such as breaks or partial degradation. Although not frequently encountered, these events suggest that the S form is capable of provoking phagosome-cytosol communication. In conclusion, M. abscessus S exhibits traits inside macrophages that are reminiscent of slow-growing mycobacterial species.
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Affiliation(s)
- Anne-Laure Roux
- UMR1173, Inserm and UFR Des Sciences de la Santé Simone Veil, Université de Versailles Saint Quentin, Montigny, France
| | - Albertus Viljoen
- Centre National de la Recherche Scientifique FRE 3689, Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé, Université de Montpellier, 1919, Route de Mende, 34293, Montpellier, France.,Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université UM 2, Inserm, U1104, CNRS UMR7280, 13288, Marseille, France
| | - Aïcha Bah
- CNRS, Institut de Pharmacologie et de Biologie Structurale (IPBS), UMR 5089 CNRS/Université Paul Sabatier, 205 route de Narbonne, BP 64182, 31077 Toulouse Cedex 4, France
| | - Roxane Simeone
- Unité de Pathogénomique mycobactérienne, Institut Pasteur, 25 rue du Dr Roux, 75724 Paris Cedex 15, Paris, France
| | - Audrey Bernut
- Centre National de la Recherche Scientifique FRE 3689, Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé, Université de Montpellier, 1919, Route de Mende, 34293, Montpellier, France
| | - Laura Laencina
- UMR1173, Inserm and UFR Des Sciences de la Santé Simone Veil, Université de Versailles Saint Quentin, Montigny, France
| | - Therese Deramaudt
- UMR1179, Inserm and UFR Des Sciences de la Santé Simone Veil, Université de Versailles Saint Quentin, Montigny, France
| | - Martin Rottman
- UMR1173, Inserm and UFR Des Sciences de la Santé Simone Veil, Université de Versailles Saint Quentin, Montigny, France
| | - Jean-Louis Gaillard
- UMR1173, Inserm and UFR Des Sciences de la Santé Simone Veil, Université de Versailles Saint Quentin, Montigny, France
| | - Laleh Majlessi
- Unité de Pathogénomique mycobactérienne, Institut Pasteur, 25 rue du Dr Roux, 75724 Paris Cedex 15, Paris, France
| | - Roland Brosch
- Unité de Pathogénomique mycobactérienne, Institut Pasteur, 25 rue du Dr Roux, 75724 Paris Cedex 15, Paris, France
| | - Fabienne Girard-Misguich
- UMR1173, Inserm and UFR Des Sciences de la Santé Simone Veil, Université de Versailles Saint Quentin, Montigny, France
| | - Isabelle Vergne
- CNRS, Institut de Pharmacologie et de Biologie Structurale (IPBS), UMR 5089 CNRS/Université Paul Sabatier, 205 route de Narbonne, BP 64182, 31077 Toulouse Cedex 4, France
| | - Chantal de Chastellier
- Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université UM 2, Inserm, U1104, CNRS UMR7280, 13288, Marseille, France
| | - Laurent Kremer
- Centre National de la Recherche Scientifique FRE 3689, Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé, Université de Montpellier, 1919, Route de Mende, 34293, Montpellier, France .,INSERM, CPBS, 34293 Montpellier, France
| | - Jean-Louis Herrmann
- UMR1173, Inserm and UFR Des Sciences de la Santé Simone Veil, Université de Versailles Saint Quentin, Montigny, France
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Radomski N, Rebbig A, Leonhardt RM, Knittler MR. Xenophagic pathways and their bacterial subversion in cellular self-defense - παντα ρει - everything is in flux. Int J Med Microbiol 2017; 308:185-196. [PMID: 29126745 DOI: 10.1016/j.ijmm.2017.10.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 10/24/2017] [Accepted: 10/29/2017] [Indexed: 01/09/2023] Open
Abstract
Autophagy is an evolutionarily ancient and highly conserved eukaryotic mechanism that targets cytoplasmic material for degradation. Autophagic flux involves the formation of autophagosomes and their degradation by lysosomes. The process plays a crucial role in maintaining cellular homeostasis and responds to various environmental conditions. While autophagy had previously been thought to be a non-selective process, it is now clear that it can also selectively target cellular organelles, such as mitochondria (referred to as mitophagy) and/or invading pathogens (referred to as xenophagy). Selective autophagy is characterized by specific substrate recognition and requires distinct cellular adaptor proteins. Here we review xenophagic mechanisms involved in the recognition and autolysosomal or autophagolysosomal degradation of different intracellular bacteria. In this context, we also discuss a recently discovered cellular self-defense pathway, termed mito-xenophagy, which occurs during bacterial infection of dendritic cells and depends on a TNF-α-mediated metabolic switch from oxidative phosphorylation to glycolysis.
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Affiliation(s)
- Nadine Radomski
- Institute of Immunology, Friedrich-Loeffler-Institut, Institute of Immunology, Federal Research Institute of Animal Health, D-17493 Greifswald, Isle of Riems, Germany
| | - Annica Rebbig
- Institute of Immunology, Friedrich-Loeffler-Institut, Institute of Immunology, Federal Research Institute of Animal Health, D-17493 Greifswald, Isle of Riems, Germany
| | - Ralf M Leonhardt
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06519, USA
| | - Michael R Knittler
- Institute of Immunology, Friedrich-Loeffler-Institut, Institute of Immunology, Federal Research Institute of Animal Health, D-17493 Greifswald, Isle of Riems, Germany.
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40
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Khan A, Jagannath C. Analysis of host-pathogen modulators of autophagy during Mycobacterium Tuberculosis infection and therapeutic repercussions. Int Rev Immunol 2017; 36:271-286. [PMID: 28976784 DOI: 10.1080/08830185.2017.1356924] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mycobacterium tuberculosis is one of the most deadly human pathogens known today in modern world, responsible for about 1.5 million deaths annually. Development of TB disease occurs only in 1 out of 10 individuals exposed to the pathogen which indicates that the competent host defense mechanisms exist in majority of the hosts to control the infection. In the last decade, autophagy has emerged as a key host immune defense mechanism against intracellular M. tuberculosis infection. Autophagy has been demonstrated not only as an effective antimicrobial mechanism for the clearance of M. tuberculosis, but the process has also been suggested to prevent excessive inflammation to avoid the adverse effects of infection on host. Nevertheless, increasing evidences also show that in order to enhance its intracellular survival, M. tuberculosis has also evolved multiple strategies to compromise the optimal functioning of host autophagic machinery. This review describes an overview of the various host signaling pathways such as pattern recognition receptors, cytokines, nutrient starvation and other cellular stress that have been implicated in induction of autophagy during M. tuberculosis infection. The review also chalk out the complex interplay of several bacterial factors of M. tuberculosis that are known to be involved in compromising autophagy mediated defense of the host. A comprehensive understanding of the interaction of bacterial and host factors at the intersections of autophagic pathways could provide integrative insights for the development of autophagy-based prophylactics and novel therapeutic interventions for TB.
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Affiliation(s)
- Arshad Khan
- a Department of Pathology and Laboratory Medicine, McGovern Medical School , University of Texas Health Sciences Center-Houston , Houston TX
| | - Chinnaswamy Jagannath
- a Department of Pathology and Laboratory Medicine, McGovern Medical School , University of Texas Health Sciences Center-Houston , Houston TX
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Wang J, Wang R, Wang H, Yang X, Yang J, Xiong W, Wen Q, Ma L. Glucocorticoids Suppress Antimicrobial Autophagy and Nitric Oxide Production and Facilitate Mycobacterial Survival in Macrophages. Sci Rep 2017; 7:982. [PMID: 28428627 PMCID: PMC5430514 DOI: 10.1038/s41598-017-01174-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 03/22/2017] [Indexed: 01/21/2023] Open
Abstract
Chronic administration of glucocorticoids has been shown to render individuals highly susceptible to mycobacterial infection and lead to reactivation of latent bacilli. However, the effect of glucocorticoids on innate anti-mycobacterial defense, especially in macrophages remains largely unknown. Here, we found that glucocorticoids inhibited the innate immune response, antimicrobial nitric oxide production and autophagy in mycobacteria-challenged macrophages. Meanwhile, maturation and acidification of mycobacterial phagosomes were attenuated in RAW264.7 cells after glucocorticoids treatment. Consequently, we observed a glucocorticoid-induced increase in the survival of intracellular mycobacteria in both primary macrophages and cell lines. Glucocorticoids treatment decreased the activation of TBK1 kinase, which promotes the maturation of autophagosomes. Inhibition of TBK1 also decreased the production of nitric oxide. Furthermore, several autophagy-related genes were down-regulated, while activation of the Akt/mTOR signaling pathway was increased after glucocorticoids treatment, which may account for autophagy inhibition during mycobacterial infection. Restoration of autophagy with the agonist rapamycin abolished glucocorticoid-mediated enhancement of mycobacterial survival, suggesting that glucocorticoids blocked anti-mycobacterial defense via autophagy inhibition. Collectively, this study demonstrates that glucocorticoids impair innate antimicrobial autophagy and promote mycobacterial survival in macrophages, which is a novel mechanism for glucocorticoid-mediated immunosuppression. Our findings may provide important clues for tuberculosis prevention.
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Affiliation(s)
- Jinli Wang
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, 510515, China
| | - Ruining Wang
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, 510515, China
| | - Hui Wang
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, 510515, China
| | - Xiaofan Yang
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, 510515, China
| | - Jiahui Yang
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, 510515, China
| | - Wenjing Xiong
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, 510515, China
| | - Qian Wen
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, 510515, China
| | - Li Ma
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, 510515, China.
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Mycobacterium marinum antagonistically induces an autophagic response while repressing the autophagic flux in a TORC1- and ESX-1-dependent manner. PLoS Pathog 2017; 13:e1006344. [PMID: 28414774 PMCID: PMC5407849 DOI: 10.1371/journal.ppat.1006344] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 04/27/2017] [Accepted: 04/11/2017] [Indexed: 12/18/2022] Open
Abstract
Autophagy is a eukaryotic catabolic process also participating in cell-autonomous defence. Infected host cells generate double-membrane autophagosomes that mature in autolysosomes to engulf, kill and digest cytoplasmic pathogens. However, several bacteria subvert autophagy and benefit from its machinery and functions. Monitoring infection stages by genetics, pharmacology and microscopy, we demonstrate that the ESX-1 secretion system of Mycobacterium marinum, a close relative to M. tuberculosis, upregulates the transcription of autophagy genes, and stimulates autophagosome formation and recruitment to the mycobacteria-containing vacuole (MCV) in the host model organism Dictyostelium. Antagonistically, ESX-1 is also essential to block the autophagic flux and deplete the MCV of proteolytic activity. Activators of the TORC1 complex localize to the MCV in an ESX-1-dependent manner, suggesting an important role in the manipulation of autophagy by mycobacteria. Our findings suggest that the infection by M. marinum activates an autophagic response that is simultaneously repressed and exploited by the bacterium to support its survival inside the MCV. One of the cell-autonomous defence pathways against intracellular pathogens is autophagy, an ancestral eukaryotic process surprisingly conserved throughout evolution. Recent studies have highlighted contradictory roles for autophagy during mycobacterial infection. Whereas some studies revealed a role for autophagy to control intracellular bacterial growth, others brought evidence that mycobacteria somehow inhibit autophagic killing. Here, we demonstrate for the first time that Mycobacterium marinum induces both an early autophagic response and its simultaneous repression by blocking the autophagic digestion. This antagonistic manipulation of autophagy is dependent on a functional ESX-1-secretion system, which secretes the membrane-damaging factor ESAT-6, proposed to participate in the perforation of the M. marinum-containing vacuole (MCV). We show here that these membrane damages activate the formation of autophagosomes and their recruitment to the MCV. However, M. marinum also utilizes its ESX-1 secretion system to avoid killing inside autolysosomes by blocking the autophagic flux. In addition, we bring evidence that this manipulation of autophagy is orchestrated via the regulation of TORC1, the major eukaryotic kinase complex controlling nutrient-sensing and cell metabolism.
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Brown RE, Hunter RL, Hwang SA. Morphoproteomic-Guided Host-Directed Therapy for Tuberculosis. Front Immunol 2017; 8:78. [PMID: 28210262 PMCID: PMC5288338 DOI: 10.3389/fimmu.2017.00078] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 01/17/2017] [Indexed: 01/08/2023] Open
Abstract
In an effort to develop more effective therapy for tuberculosis (TB), research efforts are looking toward host-directed therapy, reprograming the body's natural defenses to better control the infection. While significant progress is being made, the efforts are limited by lack of understanding of the pathology and pathogenesis of adult type TB disease. We have recently published evidence that the developing lesions in human lungs are focal endogenous lipid pneumonia that constitutes a region of local susceptibility in a person with strong systemic immunity. Since most such lesions regress spontaneously, the ability to study them directly with immunohistochemistry provides means to investigate why some progress to clinical disease while others asymptomatically regress. Furthermore, this should enable us to develop more effective host-directed therapies. Morphoproteomics has proven to be an effective means of characterizing protein expression that can be used to identify metabolic pathways, which can lead to more effective therapies. The purpose of this perspective will argue that using morphoproteomics on human TB lung tissue is a particularly promising method to direct selection of host-directed therapeutics.
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Affiliation(s)
- Robert E Brown
- Department of Pathology and Laboratory Medicine, McGovern Medical School, University of Texas Health Science Center at Houston , Houston, TX , USA
| | - Robert L Hunter
- Department of Pathology and Laboratory Medicine, McGovern Medical School, University of Texas Health Science Center at Houston , Houston, TX , USA
| | - Shen-An Hwang
- Department of Pathology and Laboratory Medicine, McGovern Medical School, University of Texas Health Science Center at Houston , Houston, TX , USA
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44
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Silva BJDA, Barbosa MGDM, Andrade PR, Ferreira H, Nery JADC, Côrte-Real S, da Silva GMS, Rosa PS, Fabri M, Sarno EN, Pinheiro RO. Autophagy Is an Innate Mechanism Associated with Leprosy Polarization. PLoS Pathog 2017; 13:e1006103. [PMID: 28056107 PMCID: PMC5215777 DOI: 10.1371/journal.ppat.1006103] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/29/2016] [Indexed: 01/04/2023] Open
Abstract
Leprosy is a chronic infectious disease that may present different clinical forms according to the immune response of the host. Levels of IFN-γ are significantly raised in paucibacillary tuberculoid (T-lep) when compared with multibacillary lepromatous (L-lep) patients. IFN-γ primes macrophages for inflammatory activation and induces the autophagy antimicrobial mechanism. The involvement of autophagy in the immune response against Mycobacterium leprae remains unexplored. Here, we demonstrated by different autophagic assays that LC3-positive autophagosomes were predominantly observed in T-lep when compared with L-lep lesions and skin-derived macrophages. Accumulation of the autophagic receptors SQSTM1/p62 and NBR1, expression of lysosomal antimicrobial peptides and colocalization analysis of autolysosomes revealed an impairment of the autophagic flux in L-lep cells, which was restored by IFN-γ or rapamycin treatment. Autophagy PCR array gene-expression analysis revealed a significantly upregulation of autophagy genes (BECN1, GPSM3, ATG14, APOL1, and TPR) in T-lep cells. Furthermore, an upregulation of autophagy genes (TPR, GFI1B and GNAI3) as well as LC3 levels was observed in cells of L-lep patients that developed type 1 reaction (T1R) episodes, an acute inflammatory condition associated with increased IFN-γ levels. Finally, we observed increased BCL2 expression in L-lep cells that could be responsible for the blockage of BECN1-mediated autophagy. In addition, in vitro studies demonstrated that dead, but not live M. leprae can induce autophagy in primary and lineage human monocytes, and that live mycobacteria can reduce the autophagy activation triggered by dead mycobacteria, suggesting that M. leprae may hamper the autophagic machinery as an immune escape mechanism. Together, these results indicate that autophagy is an important innate mechanism associated with the M. leprae control in skin macrophages. Leprosy is an interesting model to study immune responses in humans due to the dichotomy observed among the poles of the disease. While in the self-limited tuberculoid form (T-lep) there are high systemic levels of the cytokine IFN-γ, in the clinically progressive lepromatous form (L-lep) low IFN-γ levels are found. IFN-γ activates an antimicrobial mechanism called autophagy, which has been implicated in control of Mycobacterium tuberculosis infection. However, the role played by autophagy in the immunopathogenesis of leprosy remains unknown. Here we show that autophagy was differentially regulated in T-lep and L-lep patients. In T-lep skin lesion cells autophagy contributes for bacilli control, whereas in L-lep cells the BCL2-mediated block of autophagy promotes the mycobacterial persistence. We also observed that IFN-γ may counteract the inhibition of autophagy triggered by M. leprae infection in L-lep macrophages. In addition, the levels of autophagy were restored in L-lep patients who developed the reversal reaction, an inflammatory state associated with augmented IFN-γ, which is the most important cause of nerve damage and deformities in leprosy. These findings suggest that the modulation of autophagy has the potential to be useful in the treatment of the disease, and provides new insights to prevent leprosy reactional episodes.
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Affiliation(s)
| | | | - Priscila Ribeiro Andrade
- Leprosy Laboratory; Oswaldo Cruz Institute; Oswaldo Cruz Foundation, FIOCRUZ; Rio de Janeiro, Brazil
| | - Helen Ferreira
- Leprosy Laboratory; Oswaldo Cruz Institute; Oswaldo Cruz Foundation, FIOCRUZ; Rio de Janeiro, Brazil
| | | | - Suzana Côrte-Real
- Structural Biology Laboratory; Oswaldo Cruz Institute; Oswaldo Cruz Foundation, FIOCRUZ; Rio de Janeiro, Brazil
| | | | | | - Mario Fabri
- Department of Dermatology; University of Cologne; Cologne, Germany
- Center for Molecular Medicine; University of Cologne; Cologne, Germany
| | - Euzenir Nunes Sarno
- Leprosy Laboratory; Oswaldo Cruz Institute; Oswaldo Cruz Foundation, FIOCRUZ; Rio de Janeiro, Brazil
| | - Roberta Olmo Pinheiro
- Leprosy Laboratory; Oswaldo Cruz Institute; Oswaldo Cruz Foundation, FIOCRUZ; Rio de Janeiro, Brazil
- * E-mail:
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Guo L, Zhao J, Qu Y, Yin R, Gao Q, Ding S, Zhang Y, Wei J, Xu G. microRNA-20a Inhibits Autophagic Process by Targeting ATG7 and ATG16L1 and Favors Mycobacterial Survival in Macrophage Cells. Front Cell Infect Microbiol 2016; 6:134. [PMID: 27803889 PMCID: PMC5067373 DOI: 10.3389/fcimb.2016.00134] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 10/03/2016] [Indexed: 12/04/2022] Open
Abstract
Autophagy plays important roles in the host immune response against mycobacterial infection. Mycobacterium tuberculosis (M. tuberculosis) can live in macrophages owing to its ability to evade attacks by regulating autophagic response. MicroRNAs (miRNAs) are small noncoding, endogenously encoded RNA which plays critical roles in precise regulation of macrophage functions. Whether miRNAs specifically influence the activation of macrophage autophagy during M. tuberculosis infection are largely unknown. In this study, we demonstrate that BCG infection of macrophages resulted in enhanced expression of miRNA-20a, which inhibits autophagic process by targeting ATG7 and ATG16L1 and promotes BCG survival in macrophages. Forced overexpression of miR-20a decreased the expression levels of LC3-II and the number of LC3 puncta in macrophages, and promoted BCG survival in macrophages, while transfection with miR-20a inhibitor had the opposite effect. Moreover, the inhibitory effect of miR-20a on autophagy was further confirmed by transmission electron microscopy (TEM) analysis. Quantification of autophagosomes per cellular cross-section revealed a significant reduction upon transfection with miR-20a mimic, but transfection with miR-20a inhibitor increased the number of autophagosomes per cellular cross-section. Moreover, silencing of ATG7 significantly inhibited autophagic response, and transfection with ATG7 siRNA plus miR-20a mimic could further decrease autophagic response. Collectively, our data reveal that miR-20a inhibits autophagic response and promotes BCG survival in macrophages by targeting ATG7 and ATG16L1, which may have implications for a better understanding of pathogenesis of M. tuberculosis infection.
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Affiliation(s)
- Le Guo
- Ningxia Key Laboratory of Clinical and Pathogenic Microbiology, General Hospital of Ningxia Medical UniversityYinchuan, China; Department of Medical Laboratory, School of Clinical Medicine, Ningxia Medical UniversityYinchuan, China; Ningxia Key Laboratory of Clinical and Pathogenic MicrobiologyYinchuan, China
| | - Jin Zhao
- Department of Medical Laboratory, School of Clinical Medicine, Ningxia Medical UniversityYinchuan, China; Ningxia Key Laboratory of Clinical and Pathogenic MicrobiologyYinchuan, China; Clinical Laboratory, General Hospital of Tianjin Medical UniversityTianjin, China
| | - Yuliang Qu
- Department of Medical Laboratory, School of Clinical Medicine, Ningxia Medical UniversityYinchuan, China; Ningxia Key Laboratory of Clinical and Pathogenic MicrobiologyYinchuan, China
| | - Runting Yin
- Medical School of Nantong University, Nantong University Nantong, China
| | - Qian Gao
- Department of Medical Laboratory, School of Clinical Medicine, Ningxia Medical UniversityYinchuan, China; Ningxia Key Laboratory of Clinical and Pathogenic MicrobiologyYinchuan, China
| | - Shuqin Ding
- Department of Medical Laboratory, School of Clinical Medicine, Ningxia Medical UniversityYinchuan, China; Ningxia Key Laboratory of Clinical and Pathogenic MicrobiologyYinchuan, China
| | - Ying Zhang
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University Baltimore, MD, USA
| | - Jun Wei
- Ningxia Key Laboratory of Clinical and Pathogenic Microbiology, General Hospital of Ningxia Medical UniversityYinchuan, China; Department of Medical Laboratory, School of Clinical Medicine, Ningxia Medical UniversityYinchuan, China; Ningxia Key Laboratory of Clinical and Pathogenic MicrobiologyYinchuan, China
| | - Guangxian Xu
- Ningxia Key Laboratory of Clinical and Pathogenic Microbiology, General Hospital of Ningxia Medical UniversityYinchuan, China; Department of Medical Laboratory, School of Clinical Medicine, Ningxia Medical UniversityYinchuan, China; Ningxia Key Laboratory of Clinical and Pathogenic MicrobiologyYinchuan, China
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Deretic V. Autophagy in leukocytes and other cells: mechanisms, subsystem organization, selectivity, and links to innate immunity. J Leukoc Biol 2016; 100:969-978. [PMID: 27493243 DOI: 10.1189/jlb.4mr0216-079r] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 07/06/2016] [Indexed: 12/20/2022] Open
Abstract
Autophagy is a fundamental biologic process that fulfills general and specialized roles in cytoplasmic homeostasis. The cell-autonomous antimicrobial functions of autophagy have been established in the macrophage. These cells and other leukocytes continue to be the cells of choice in studying autophagy in immunity and inflammation. This review uses several model examples that will be of interest to leukocyte and cell biologists alike. Furthermore, it comprehensively covers the subsystems in autophagy as they apply to all mammalian cells and incorporates the recent progress in our understanding of how these modules come together-a topic that should be of interest to all readers.
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Affiliation(s)
- Vojo Deretic
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
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Autophagy induction targeting mTORC1 enhances Mycobacterium tuberculosis replication in HIV co-infected human macrophages. Sci Rep 2016; 6:28171. [PMID: 27302320 PMCID: PMC4908603 DOI: 10.1038/srep28171] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 05/31/2016] [Indexed: 12/30/2022] Open
Abstract
To survive and replicate in macrophages Mycobacterium tuberculosis (Mtb) has developed strategies to subvert host defence mechanisms, including autophagy. Autophagy induction has the potential to clear Mtb, but little is known about its effect during controlled tuberculosis and HIV co-infection. Mammalian target of rapamycin complex1 (mTORC1) inhibitors were used to induce autophagy in human macrophages pre-infected with HIV-1BaL and infected with a low dose of Mtb (co-infected), or single Mtb infected (single infected). The controlled Mtb infection was disrupted upon mTOR inhibition resulting in increased Mtb replication in a dose-dependent manner which was more pronounced during co-infection. The increased Mtb replication could be explained by the marked reduction in phagosome acidification upon mTOR inhibition. Autophagy stimulation targeting mTORC1 clearly induced a basal autophagy with flux that was unlinked to the subcellular environment of the Mtb vacuoles, which showed a concurrent suppression in acidification and maturation/flux. Overall our findings indicate that mTOR inhibition during Mtb or HIV/Mtb co-infection interferes with phagosomal maturation, thereby supporting mycobacterial growth during low-dose and controlled infection. Therefore pharmacological induction of autophagy through targeting of the canonical mTORC1-pathway should be handled with caution during controlled tuberculosis, since this could have serious consequences for patients with HIV/Mtb co-infection.
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48
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Bah A, Lacarrière C, Vergne I. Autophagy-Related Proteins Target Ubiquitin-Free Mycobacterial Compartment to Promote Killing in Macrophages. Front Cell Infect Microbiol 2016; 6:53. [PMID: 27242971 PMCID: PMC4863073 DOI: 10.3389/fcimb.2016.00053] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 04/26/2016] [Indexed: 01/02/2023] Open
Abstract
Autophagy is a lysosomal degradative process that plays essential functions in innate immunity, particularly, in the clearance of intracellular bacteria such as Mycobacterium tuberculosis. The molecular mechanisms involved in autophagy activation and targeting of mycobacteria, in innate immune responses of macrophages, are only partially characterized. Autophagy targets pathogenic M. tuberculosis via a cytosolic DNA recognition- and an ubiquitin-dependent pathway. In this report, we show that non-pathogenic M. smegmatis induces a robust autophagic response in THP-1 macrophages with an up regulation of several autophagy-related genes. Autophagy activation relies in part on recognition of mycobacteria by Toll-like receptor 2 (TLR2). Notably, LC3 targeting of M. smegmatis does not rely on membrane damage, ubiquitination, or autophagy receptor recruitment. Lastly, M. smegmatis promotes recruitment of several autophagy proteins, which are required for mycobacterial killing. In conclusion, our study uncovered an alternative autophagic pathway triggered by mycobacteria which involves cell surface recognition but not bacterial ubiquitination.
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Affiliation(s)
- Aïcha Bah
- Tuberculosis and Infection Biology, Institut de Pharmacologie et de Biologie Structurale, UMR 5089 Centre National de la Recherche Scientifique - Université de Toulouse Toulouse, France
| | - Camille Lacarrière
- Tuberculosis and Infection Biology, Institut de Pharmacologie et de Biologie Structurale, UMR 5089 Centre National de la Recherche Scientifique - Université de Toulouse Toulouse, France
| | - Isabelle Vergne
- Tuberculosis and Infection Biology, Institut de Pharmacologie et de Biologie Structurale, UMR 5089 Centre National de la Recherche Scientifique - Université de Toulouse Toulouse, France
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Kadir NA, Sarmiento ME, Acosta A, Norazmi MN. Cellular and humoral immunogenicity of recombinant Mycobacterium smegmatis expressing Ag85B epitopes in mice. Int J Mycobacteriol 2016; 5:7-13. [DOI: 10.1016/j.ijmyco.2015.09.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Revised: 09/22/2015] [Accepted: 09/27/2015] [Indexed: 10/22/2022] Open
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50
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Au KY, Pong JCH, Ling WL, Li JCB. MiR-1303 Regulates Mycobacteria Induced Autophagy by Targeting Atg2B. PLoS One 2016; 11:e0146770. [PMID: 26771516 PMCID: PMC4714759 DOI: 10.1371/journal.pone.0146770] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 12/22/2015] [Indexed: 12/19/2022] Open
Abstract
MicroRNAs are emerging post-transcriptional regulators of gene expressions in both innate immunity and adaptive immunity. In mycobacteria infection, autophagy plays an important role in innate defense mechanism and is tightly regulated by the autophagy-related proteins. Here, we show that Atg2B is involved in the regulation of mycobacteria-induced autophagy. MiR-1303, which function is not defined yet, is found to negatively regulate mycobacteria-induced Atg2B protein production, ultimately down-regulate mycobacteria-induced autophagy. MiR-1303 production is shown to be upregulated during BCG infection and its production is regulated by PI3K and NFκB. It is also demonstrated that miR-1303 targets putative target sites on Atg2B and possibly represses its translation.
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Affiliation(s)
- Kin Yi Au
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - John C. H. Pong
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Wai Lim Ling
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - James C. B. Li
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- * E-mail:
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