1
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An Z, Ding W. Syntaxin17 Restores Lysosomal Function and Inhibits Pyroptosis Caused by Acinetobacter baumannii. J Microbiol 2024; 62:315-325. [PMID: 38451450 DOI: 10.1007/s12275-024-00109-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 12/12/2023] [Accepted: 01/04/2024] [Indexed: 03/08/2024]
Abstract
Acinetobacter baumannii (A. baumannii) causes autophagy flux disorder by degrading STX17, resulting in a serious inflammatory response. It remains unclear whether STX17 can alter the inflammatory response process by controlling autolysosome function. This study aimed to explore the role of STX17 in the regulation of pyroptosis induced by A. baumannii. Our findings indicate that overexpression of STX17 enhances autophagosome degradation, increases LAMP1 expression, reduces Cathepsin B release, and improves lysosomal function. Conversely, knockdown of STX17 suppresses autophagosome degradation, reduces LAMP1 expression, augments Cathepsin B release, and accelerates lysosomal dysfunction. In instances of A. baumannii infection, overexpression of STX17 was found to improve lysosomal function and reduce the expression of mature of GSDMD and IL-1β, along with the release of LDH, thus inhibiting pyroptosis caused by A. baumannii. Conversely, knockdown of STX17 led to increased lysosomal dysfunction and further enhanced the expression of mature of GSDMD and IL-1β, and increased the release of LDH, exacerbating pyroptosis induced by A. baumannii. These findings suggest that STX17 regulates pyroptosis induced by A. baumannii by modulating lysosomal function.
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Affiliation(s)
- Zhiyuan An
- Medical Research Center, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, People's Republic of China.
| | - Wenyi Ding
- Department of Clinical Laboratory, Chinese Academy of Medical Sciences, Peking Union Medical College Hospital, Beijing, 100730, People's Republic of China
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2
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Nasser F, Oke MT, Knezevic S, D'Costa VM. Bacterial Pathogenesis: Assessment of Intracellular Positioning of Pathogen-Containing Vacuoles During Infection. Curr Protoc 2024; 4:e1021. [PMID: 38619090 DOI: 10.1002/cpz1.1021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Intracellular bacterial pathogens implement a diverse array of strategies to target host cells and establish infection. For vacuolar pathogens, the process of pathogen-containing vacuole movement within host cells, termed intracellular trafficking, is central to both pathogen survival and infection progression. Typically a process mediated by secreted virulence factors that manipulate the host cytoskeletal machinery, internalized pathogen-containing vacuoles traffic to the site of replication to establish a unique replicative niche, and if applicable, traffic back toward the host cell periphery for cell-to-cell spread. As such, the intracellular positioning of pathogen-containing vacuoles represents a fundamental measure of infection progression. Here, we describe a fluorescence microscopy-based method to quantitatively assess bacterial intracellular positioning, using Salmonella enterica serovar Typhimurium infection of epithelial cells as a model. This experimental approach can be modified to study infection in diverse host cell types, and with a broad array of pathogens. The system can also be adapted to examine the kinetics of infection, identify secreted virulence factors that mediate host trafficking, investigate host factors that are targeted by the pathogen for trafficking, and assess functional domains within a virulence factor responsible for mediating the phenotype. Collectively, these tools can provide fundamental insight into the pathogenesis of a diverse array of intracellular bacterial pathogens, and new host factors that are hijacked to mediate infection. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Culture and preparation of host cells Alternate Protocol: Culture and preparation of host cells to assess host factor contribution to bacterial positioning Basic Protocol 2: Infection of epithelial cells with S. Typhimurium Basic Protocol 3: Fluorescence staining for analysis of bacterial positioning Basic Protocol 4: Fluorescence microscopy analysis of bacterial positioning.
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Affiliation(s)
- Farah Nasser
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
- Centre for Infection, Immunity and Inflammation, University of Ottawa, Ottawa, Canada
| | - Mosopefoluwa T Oke
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
- Centre for Infection, Immunity and Inflammation, University of Ottawa, Ottawa, Canada
- These authors contributed equally to this work
| | - Sara Knezevic
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
- Centre for Infection, Immunity and Inflammation, University of Ottawa, Ottawa, Canada
- These authors contributed equally to this work
| | - Vanessa M D'Costa
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
- Centre for Infection, Immunity and Inflammation, University of Ottawa, Ottawa, Canada
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3
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Mocăniță M, Martz K, D’Costa VM. Bacterial Pathogen-Mediated Suppression of Host Trafficking to Lysosomes: Fluorescence Microscopy-Based DQ-Red BSA Analysis. Bio Protoc 2024; 14:e4951. [PMID: 38464940 PMCID: PMC10917698 DOI: 10.21769/bioprotoc.4951] [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: 09/21/2023] [Revised: 12/04/2023] [Accepted: 02/05/2024] [Indexed: 03/12/2024] Open
Abstract
Intracellular bacterial pathogens have evolved to be adept at manipulating host cellular function for the benefit of the pathogen, often by means of secreted virulence factors that target host pathways for modulation. The lysosomal pathway is an essential cellular response pathway to intracellular pathogens and, as such, represents a common target for bacterial-mediated evasion. Here, we describe a method to quantitatively assess bacterial pathogen-mediated suppression of host cell trafficking to lysosomes, using Salmonella enterica serovar Typhimurium infection of epithelial cells as a model. This live-cell imaging assay involves the use of a BODIPY TR-X conjugate of BSA (DQ-Red BSA) that traffics to and fluoresces in functional lysosomes. This method can be adapted to study infection with a broad array of pathogens in diverse host cell types. It is capable of being applied to identify secreted virulence factors responsible for a phenotype of interest as well as domains within the bacterial protein that are important for mediating the phenotype. Collectively, these tools can provide invaluable insight into the mechanisms of pathogenesis of a diverse array of pathogenic bacteria, with the potential to uncover virulence factors that may be suitable targets for therapeutic intervention. Key features • Infection-based analysis of bacterial-mediated suppression of host trafficking to lysosomes, using Salmonella enterica serovar Typhimurium infection of human epithelial cells as a model. • Live microscopy-based analysis allows for the visualization of individually infected host cells and is amenable to phenotype quantification. • Assay can be adapted to a broad array of pathogens and diverse host cell types. • Assay can identify virulence factors mediating a phenotype and protein domains that mediate a phenotype.
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Affiliation(s)
- Mădălina Mocăniță
- Department of Biochemistry, Microbiology and
Immunology, University of Ottawa, Ottawa, ON, Canada
- Centre for Infection, Immunity and Inflammation,
University of Ottawa, Ottawa, ON, Canada
| | - Kailey Martz
- Department of Biochemistry, Microbiology and
Immunology, University of Ottawa, Ottawa, ON, Canada
- Centre for Infection, Immunity and Inflammation,
University of Ottawa, Ottawa, ON, Canada
| | - Vanessa M. D’Costa
- Department of Biochemistry, Microbiology and
Immunology, University of Ottawa, Ottawa, ON, Canada
- Centre for Infection, Immunity and Inflammation,
University of Ottawa, Ottawa, ON, Canada
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4
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Dwivedi R, Baindara P. Differential Regulation of TFEB-Induced Autophagy during Mtb Infection and Starvation. Microorganisms 2023; 11:2944. [PMID: 38138088 PMCID: PMC10746089 DOI: 10.3390/microorganisms11122944] [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: 10/23/2023] [Revised: 12/01/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
Through the promotion of phagolysosome formation, autophagy has emerged as a crucial mechanism to eradicate intracellular Mycobacterium tuberculosis (Mtb). A cell-autonomous host defense mechanism called lysosome biogenesis and autophagy transports cytoplasmic cargos and bacterial phagosomes to lysosomes for destruction during infection. Similar occurrences occurred in stressful or starvation circumstances and led to autophagy, which is harmful to the cell. It is interesting to note that under both hunger and infection states, the transcription factor EB (TFEB) acts as a master regulator of lysosomal activities and autophagy. This review highlighted recent research on the multitier regulation of TFEB-induced autophagy by a variety of host effectors and Mtb sulfolipid during Mtb infection and starvation. In general, the research presented here sheds light on how lysosome biogenesis and autophagy are differentially regulated by the TFEB during Mtb infection and starvation.
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Affiliation(s)
- Richa Dwivedi
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Piyush Baindara
- Radiation Oncology, NextGen Precision Health, School of Medicine, University of Missouri, Columbia, MO 65211, USA
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5
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Huang XW, Lu S, Pan W, Zhong MZ, Chai JW, Liu YH, Zeng K, Xi LY. Autophagy benefits the in vitro and in vivo clearance of Talaromyces marneffei. Microb Pathog 2023; 180:106146. [PMID: 37150309 DOI: 10.1016/j.micpath.2023.106146] [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: 04/06/2023] [Revised: 05/01/2023] [Accepted: 05/04/2023] [Indexed: 05/09/2023]
Abstract
Talaromycosis, namely Talaromyces marneffei infection, is increasing gradually and has a high mortality rate even under antifungal therapy. Although autophagy acts differently on different pathogens, it is a promising therapeutic strategy. However, information on autophagy in macrophages and animals upon infection by T. marneffei is still limited. Therefore, several models were employed here to investigate the role of autophagy in host defense against T. marneffei, including RAW264.7 macrophages as in vitro models, different types of Caenorhabditis elegans and BALB/c mice as in vivo models. We applied the clinical T. marneffei isolate SUMS0152 in this study. T. marneffei-infected macrophages exhibit increased formation of autophagosomes. Further, macrophage autophagy promoted by rapamycin or Earle's balanced salt solution (EBSS) inhibited the viability of intracellular T. marneffei. In vivo, compared with uninfected Caenorhabditis elegans, the wild-type nematodes upregulated the expression of the autophagy-related gene lgg-1 and atg-18, and nematodes carrying GFP reporter were induced to form autophagosomes (GFP::LGG-1) after T. marneffei infection. Furthermore, the knockdown of lgg-1 significantly reduced the survival rate of T. marneffei-infected nematodes. Likewise, the autophagy activator rapamycin reduced the fungal burden and suppressed lung inflammation in a mouse model of infection. In conclusion, autophagy is essential for host defense against T. marneffei in vitro and in vivo. Therefore, autophagy may be an attractive target for developing new therapeutics to treat talaromycosis.
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Affiliation(s)
- Xiao-Wen Huang
- Department of Dermatology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Sha Lu
- Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, 107 West Yanjiang Rd., Guangzhou, 510120, China
| | - Wen Pan
- Division of Infectious Diseases, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, 02903, USA
| | - Mei-Zhen Zhong
- Department of Dermatology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Jin-Wei Chai
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Ying-Hui Liu
- Dermatology Department, Dermatology Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Kang Zeng
- Department of Dermatology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
| | - Li-Yan Xi
- Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, 107 West Yanjiang Rd., Guangzhou, 510120, China; Dermatology Department, Dermatology Hospital, Southern Medical University, Guangzhou, 510515, China.
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6
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Banday MM, Rao SB, Shankar S, Khanday MA, Finan J, O'Neill E, Coppolino A, Seyfang A, Kumar A, Rinewalt DE, Goldberg HJ, Woolley A, Mallidi HR, Visner G, Gaggar A, Patel KN, Sharma NS. IL-33 mediates Pseudomonas induced airway fibrogenesis and is associated with CLAD. J Heart Lung Transplant 2023; 42:53-63. [PMID: 37014805 PMCID: PMC10260236 DOI: 10.1016/j.healun.2022.09.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/21/2022] [Accepted: 09/22/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Long term outcomes of lung transplantation are impacted by the occurrence of chronic lung allograft dysfunction (CLAD). Recent evidence suggests a role for the lung microbiome in the occurrence of CLAD, but the exact mechanisms are not well defined. We hypothesize that the lung microbiome inhibits epithelial autophagic clearance of pro-fibrotic proteins in an IL-33 dependent manner, thereby augmenting fibrogenesis and risk for CLAD. METHODS Autopsy derived CLAD and non-CLAD lungs were collected. IL-33, P62 and LC3 immunofluorescence was performed and assessed using confocal microscopy. Pseudomonas aeruginosa (PsA), Streptococcus Pneumoniae (SP), Prevotella Melaninogenica (PM), recombinant IL-33 or PsA-lipopolysaccharide was co-cultured with primary human bronchial epithelial cells (PBEC) and lung fibroblasts in the presence or absence of IL-33 blockade. Western blot analysis and quantitative reverse transcription (qRT) PCR was performed to evaluate IL-33 expression, autophagy, cytokines and fibroblast differentiation markers. These experiments were repeated after siRNA silencing and upregulation (plasmid vector) of Beclin-1. RESULTS Human CLAD lungs demonstrated markedly increased expression of IL-33 and reduced basal autophagy compared to non-CLAD lungs. Exposure of co-cultured PBECs to PsA, SP induced IL-33, and inhibited PBEC autophagy, while PM elicited no significant response. Further, PsA exposure increased myofibroblast differentiation and collagen formation. IL-33 blockade in these co-cultures recovered Beclin-1, cellular autophagy and attenuated myofibroblast activation in a Beclin-1 dependent manner. CONCLUSION CLAD is associated with increased airway IL-33 expression and reduced basal autophagy. PsA induces a fibrogenic response by inhibiting airway epithelial autophagy in an IL-33 dependent manner.
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Affiliation(s)
- Mudassir M Banday
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | | | - Shruthi Shankar
- University of South Florida, Morsani College of Medicine/Tampa General Hospital
| | | | - Jon Finan
- University of South Florida, Morsani College of Medicine/Tampa General Hospital
| | - Edward O'Neill
- University of South Florida, Morsani College of Medicine/Tampa General Hospital
| | - Antonio Coppolino
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Andreas Seyfang
- University of South Florida, Morsani College of Medicine/Tampa General Hospital
| | - Archit Kumar
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Daniel E Rinewalt
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Hilary J Goldberg
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ann Woolley
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Hari Reddy Mallidi
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Gary Visner
- Boston Children's Hospital. Harvard Medical School
| | | | - Kapil N Patel
- University of South Florida, Morsani College of Medicine/Tampa General Hospital
| | - Nirmal S Sharma
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; Boston VA Medical Center.
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7
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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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8
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Jiao Y, Cao S, Zhang Y, Tan Y, Zhou Y, Wang T, You Y, Chen H, Ren Y, Yang R, Du Z. Yersinia pestis-Induced Mitophagy That Balances Mitochondrial Homeostasis and mROS-Mediated Bactericidal Activity. Microbiol Spectr 2022; 10:e0071822. [PMID: 35768946 PMCID: PMC9241946 DOI: 10.1128/spectrum.00718-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 05/20/2022] [Indexed: 12/28/2022] Open
Abstract
Manipulating mitochondrial homeostasis is essential for host defense against infection and pathogen survival in cells. This study reports for the first time that Y. pestis infection caused mitochondria damage that subsequently leads to the activation of Pink1/Parkin-independent mitophagy in macrophage, and the effector YopH from the type III secretion system was required for these effects. The generation of mitochondrial reactive oxygen species (mROS) by damaged mitochondria enhances the antibacterial activity of macrophages against Y. pestis and promotes apoptosis of the infected cells. Therefore, Y. pestis-induced mitophagy was employed to eliminate dysfunctional mitochondria and relieve the mROS accumulation. This study reveals a novel role for YopH of Y. pestis in damaging host macrophage mitochondria during plague infection and underlines the vital role of mitophagy in maintaining mitochondrial homeostasis by clearing bacteria-damaged mitochondria. The results show that mitophagy or mitochondrial fission manipulation could be used as a new strategy to treat plague. IMPORTANCE Y. pestis, the pathogen of plague, also known as the "Black Death," has caused millions of deaths throughout history. This study reports that Y. pestis infection induces mitochondrial fragmentation and abnormal mROS accumulation, and releases mitochondrial contents into the cytoplasm in macrophages. mROS promotes the antibacterial activity of macrophages against Y. pestis and increases apoptosis of the infected cells. PINK-Parkin-independent mitophagy is activated to balance mitochondrial homeostasis and mROS-induced bactericidal activity in Y. pestis-infected macrophages. These findings deepen the understanding of Y. pestis pathogenesis on mitochondria damage to disturb the host cellular immune elimination. Manipulating mitophagic activity or mitochondrial fission may be a novel therapeutic approach to treat plague.
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Affiliation(s)
- Yang Jiao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Shiyang Cao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Yuan Zhang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Yafang Tan
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Yazhou Zhou
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Tong Wang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Yang You
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Hongyan Chen
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Yifan Ren
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Ruifu Yang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Zongmin Du
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
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9
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Grijmans BJM, van der Kooij SB, Varela M, Meijer AH. LAPped in Proof: LC3-Associated Phagocytosis and the Arms Race Against Bacterial Pathogens. Front Cell Infect Microbiol 2022; 11:809121. [PMID: 35047422 PMCID: PMC8762105 DOI: 10.3389/fcimb.2021.809121] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 12/10/2021] [Indexed: 01/05/2023] Open
Abstract
Cells of the innate immune system continuously patrol the extracellular environment for potential microbial threats that are to be neutralized by phagocytosis and delivery to lysosomes. In addition, phagocytes employ autophagy as an innate immune mechanism against pathogens that succeed to escape the phagolysosomal pathway and invade the cytosol. In recent years, LC3-associated phagocytosis (LAP) has emerged as an intermediate between phagocytosis and autophagy. During LAP, phagocytes target extracellular microbes while using parts of the autophagic machinery to label the cargo-containing phagosomes for lysosomal degradation. LAP contributes greatly to host immunity against a multitude of bacterial pathogens. In the pursuit of survival, bacteria have developed elaborate strategies to disarm or circumvent the LAP process. In this review, we will outline the nature of the LAP mechanism and discuss recent insights into its interplay with bacterial pathogens.
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Affiliation(s)
| | | | - Monica Varela
- Institute of Biology Leiden, Leiden University, Leiden, Netherlands
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10
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Shoubridge AP, Fourrier C, Choo JM, Proud CG, Sargeant TJ, Rogers GB. Gut Microbiome Regulation of Autophagic Flux and Neurodegenerative Disease Risks. Front Microbiol 2022; 12:817433. [PMID: 35003048 PMCID: PMC8733410 DOI: 10.3389/fmicb.2021.817433] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 12/02/2021] [Indexed: 11/21/2022] Open
Abstract
The gut microbiome-brain axis exerts considerable influence on the development and regulation of the central nervous system. Numerous pathways have been identified by which the gut microbiome communicates with the brain, falling largely into the two broad categories of neuronal innervation and immune-mediated mechanisms. We describe an additional route by which intestinal microbiology could mediate modifiable risk for neuropathology and neurodegeneration in particular. Autophagy, a ubiquitous cellular process involved in the prevention of cell damage and maintenance of effective cellular function, acts to clear and recycle cellular debris. In doing so, autophagy prevents the accumulation of toxic proteins and the development of neuroinflammation, both common features of dementia. Levels of autophagy are influenced by a range of extrinsic exposures, including nutrient deprivation, infection, and hypoxia. These relationships between exposures and rates of autophagy are likely to be mediated, as least in part, by the gut microbiome. For example, the suppression of histone acetylation by microbiome-derived short-chain fatty acids appears to be a major contributor to upregulation of autophagic function. We discuss the potential contribution of the microbiome-autophagy axis to neurological health and examine the potential of exploiting this link to predict and prevent neurodegenerative diseases.
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Affiliation(s)
- Andrew P Shoubridge
- Microbiome and Host Health, Lifelong Health, South Australian Health and Medical Research Institute, Adelaide, SA, Australia.,Infection and Immunity, Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Célia Fourrier
- Lysosomal Health in Ageing, Hopwood Centre for Neurobiology, Lifelong Health, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| | - Jocelyn M Choo
- Microbiome and Host Health, Lifelong Health, South Australian Health and Medical Research Institute, Adelaide, SA, Australia.,Infection and Immunity, Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Christopher G Proud
- Nutrition, Diabetes and Gut Health, Lifelong Health, South Australian Health and Medical Research Institute, Adelaide, SA, Australia.,School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Timothy J Sargeant
- Lysosomal Health in Ageing, Hopwood Centre for Neurobiology, Lifelong Health, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| | - Geraint B Rogers
- Microbiome and Host Health, Lifelong Health, South Australian Health and Medical Research Institute, Adelaide, SA, Australia.,Infection and Immunity, Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
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11
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Schultz BM, Melo-Gonzalez F, Salazar GA, Porto BN, Riedel CA, Kalergis AM, Bueno SM. New Insights on the Early Interaction Between Typhoid and Non-typhoid Salmonella Serovars and the Host Cells. Front Microbiol 2021; 12:647044. [PMID: 34276584 PMCID: PMC8282409 DOI: 10.3389/fmicb.2021.647044] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 06/08/2021] [Indexed: 11/13/2022] Open
Abstract
Salmonella enterica is a common source of food and water-borne infections, causing a wide range of clinical ailments in both human and animal hosts. Immunity to Salmonella involves an interplay between different immune responses, which are rapidly initiated to control bacterial burden. However, Salmonella has developed several strategies to evade and modulate the host immune responses. In this sense, the main knowledge about the pathogenicity of this bacterium has been obtained by the study of mouse models with non-typhoidal serovars. However, this knowledge is not representative of all the pathologies caused by non-typhoidal serovars in the human. Here we review the most important features of typhoidal and non-typhoidal serovars and the diseases they cause in the human host, describing the virulence mechanisms used by these pathogens that have been identified in different models of infection.
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Affiliation(s)
- Bárbara M Schultz
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Felipe Melo-Gonzalez
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Geraldyne A Salazar
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Bárbara N Porto
- Laboratory of Clinical and Experimental Immunology, School of Medicine, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.,Program in Translational Medicine, Hospital for Sick Children, Toronto, ON, Canada
| | - Claudia A Riedel
- Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Millennium Institute on Immunology and Immunotherapy, Universidad Andrés Bello, Santiago, Chile
| | - Alexis M Kalergis
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.,Departamento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Susan M Bueno
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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12
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Ankylosing spondylitis: an autoimmune or autoinflammatory disease? Nat Rev Rheumatol 2021; 17:387-404. [PMID: 34113018 DOI: 10.1038/s41584-021-00625-y] [Citation(s) in RCA: 129] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/23/2021] [Indexed: 12/20/2022]
Abstract
Ankylosing spondylitis (AS) is a chronic inflammatory disorder of unknown aetiology. Unlike other systemic autoimmune diseases, in AS, the innate immune system has a dominant role characterized by aberrant activity of innate and innate-like immune cells, including γδ T cells, group 3 innate lymphoid cells, neutrophils, mucosal-associated invariant T cells and mast cells, at sites predisposed to the disease. The intestine is involved in disease manifestations, as it is at the forefront of the interaction between the mucosal-associated immune cells and the intestinal microbiota. Similarly, biomechanical factors, such as entheseal micro-trauma, might also be involved in the pathogenesis of the articular manifestation of AS, and sentinel immune cells located in the entheses could provide links between local damage, genetic predisposition and the development of chronic inflammation. Although these elements might support the autoinflammatory nature of AS, studies demonstrating the presence of autoantibodies (such as anti-CD74, anti-sclerostin and anti-noggin antibodies) and evidence of activation and clonal expansion of T cell populations support an autoimmune component to the disease. This Review presents the evidence for autoinflammation and the evidence for autoimmunity in AS and, by discussing the pathophysiological factors associated with each, aims to reconcile the two hypotheses.
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13
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Siegmund A, Afzal MA, Tetzlaff F, Keinhörster D, Gratani F, Paprotka K, Westermann M, Nietzsche S, Wolz C, Fraunholz M, Hübner CA, Löffler B, Tuchscherr L. Intracellular persistence of Staphylococcus aureus in endothelial cells is promoted by the absence of phenol-soluble modulins. Virulence 2021; 12:1186-1198. [PMID: 33843450 PMCID: PMC8043190 DOI: 10.1080/21505594.2021.1910455] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
A large proportion of clinical S. aureus isolates that carry an inactive Agr system are associated with persistent infection that is difficult to treat. Once S. aureus is inside the bloodstream, it can cross the endothelial barrier and invade almost every organ in the human body. Endothelial cells can either be lysed by this pathogen or they serve as a niche for its intracellular long-term survival. Following phagocytosis, several vesicles such as phagosomes and autophagosomes, target intracellular S. aureus for elimination. S. aureus can escape from these vesicles into the host cytoplasm through the activation of phenol-soluble modulins (PSMs) αβ. Thereafter, it replicates and lyses the host cell to disseminate to adjacent tissues. Herein we demonstrate that staphylococcal strains which lack the expression of PSMs employ an alternative pathway to better persist within endothelial cells. The intracellular survival of S. aureus is associated with the co-localization of the autophagy marker LC3. In cell culture infection models, we found that the absence of psmαβ decreased the host cell lysis and increased staphylococcal long-term survival. This study explains the positive selection of agr-negative strains that lack the expression of psmαβ in chronic infection due to their advantage in surviving and evading the clearance system of the host.
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Affiliation(s)
- Anke Siegmund
- Institute of Medical Microbiology, Jena University Hospital, Jena, Germany
| | - Muhammad Awais Afzal
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller Universität, Jena, Germany
| | - Felix Tetzlaff
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller Universität, Jena, Germany
| | - Daniela Keinhörster
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen, Tübingen, Germany
| | - Fabio Gratani
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen, Tübingen, Germany
| | - Kerstin Paprotka
- Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany
| | - Martin Westermann
- Center for Electron Microscopy, Jena University Hospital, Jena, Germany
| | - Sandor Nietzsche
- Center for Electron Microscopy, Jena University Hospital, Jena, Germany
| | - Christiane Wolz
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen, Tübingen, Germany
| | - Martin Fraunholz
- Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany
| | - Christian A Hübner
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller Universität, Jena, Germany
| | - Bettina Löffler
- Institute of Medical Microbiology, Jena University Hospital, Jena, Germany
| | - Lorena Tuchscherr
- Institute of Medical Microbiology, Jena University Hospital, Jena, Germany
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14
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Abstract
Epithelia are structurally integral elements in the fabric of oral mucosa with significant functional roles. Similarly, the gingival epithelium performs uniquely critical tasks in responding to a variety of external stimuli and dangers through the regulation of specific built-in molecular mechanisms in a context-dependent fashion at cellular levels. Gingival epithelial cells form an anatomic architecture that confers defense, robustness, and adaptation toward external aggressions, most critically to colonizing microorganisms, among other functions. Accordingly, recent studies unraveled previously uncharacterized response mechanisms in gingival epithelial cells that are constructed to rapidly exert biocidal effects against invader pathobiotic bacteria, such as Porphyromonas gingivalis, through small danger molecule signaling. The host-adapted bacteria, however, have developed adroit strategies to 1) exploit the epithelia as privileged growth niches and 2) chronically target cellular bactericidal and homeostatic metabolic pathways for successful bacterial persistence. As the overgrowth of colonizing microorganisms in the gingival mucosa can shift from homeostasis to dysbiosis or a diseased state, it is crucial to understand how the innate modulatory molecules are intricately involved in antibacterial pathways and how they shape susceptibility versus resistance in the epithelium toward pathogens. Thus, in this review, we highlight recent discoveries in gingival epithelial cell research in the context of bacterial colonizers. The current knowledge outlined here demonstrates the ability of epithelial cells to possess highly organized defense machineries, which can jointly regulate host-derived danger molecule signaling and integrate specific global responses against opportunistic bacteria to combat microbial incursion and maintain host homeostatic balance. These novel examples collectively suggest that the oral epithelia are equipped with a dynamically robust and interconnected defense system encompassing sensors and various effector molecules that arrange and achieve a fine-tuned and advanced response to diverse bacteria.
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Affiliation(s)
- J.S. Lee
- Department of Oral Health Sciences, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Ö. Yilmaz
- Department of Oral Health Sciences, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC, USA
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15
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Missiakas D, Winstel V. Selective Host Cell Death by Staphylococcus aureus: A Strategy for Bacterial Persistence. Front Immunol 2021; 11:621733. [PMID: 33552085 PMCID: PMC7859115 DOI: 10.3389/fimmu.2020.621733] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 12/03/2020] [Indexed: 12/12/2022] Open
Abstract
Host cell death programs are fundamental processes that shape cellular homeostasis, embryonic development, and tissue regeneration. Death signaling and downstream host cell responses are not only critical to guide mammalian development, they often act as terminal responses to invading pathogens. Here, we briefly review and contrast how invading pathogens and specifically Staphylococcus aureus manipulate apoptotic, necroptotic, and pyroptotic cell death modes to establish infection. Rather than invading host cells, S. aureus subverts these cells to produce diffusible molecules that cause death of neighboring hematopoietic cells and thus shapes an immune environment conducive to persistence. The exploitation of cell death pathways by S. aureus is yet another virulence strategy that must be juxtaposed to mechanisms of immune evasion, autophagy escape, and tolerance to intracellular killing, and brings us closer to the true portrait of this pathogen for the design of effective therapeutics and intervention strategies.
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Affiliation(s)
- Dominique Missiakas
- Howard Taylor Ricketts Laboratory, Department of Microbiology, University of Chicago, Lemont, IL, United States
| | - Volker Winstel
- Research Group Pathogenesis of Bacterial Infections, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Hannover Medical School and the Helmholtz Centre for Infection Research, Hannover, Germany
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
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16
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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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17
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Silwal P, Paik S, Kim JK, Yoshimori T, Jo EK. Regulatory Mechanisms of Autophagy-Targeted Antimicrobial Therapeutics Against Mycobacterial Infection. Front Cell Infect Microbiol 2021; 11:633360. [PMID: 33828998 PMCID: PMC8019938 DOI: 10.3389/fcimb.2021.633360] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 01/08/2021] [Indexed: 01/25/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) is an intracellular pathogen causing human tuberculosis, an infectious disease that still remains as a global health problem. Autophagy, a lysosomal degradative process, has emerged as a critical pathway to restrict intracellular Mtb growth through enhancement of phagosomal maturation. Indeed, several autophagy-modulating agents show promise as host-directed therapeutics for Mtb infection. In this Review, we discuss recent progress in our understanding the molecular mechanisms underlying the action of autophagy-modulating agents to overcome the immune escape strategies mediated by Mtb. The factors and pathways that govern such mechanisms include adenosine 5'-monophosphate-activated protein kinase, Akt/mammalian TOR kinase, Wnt signaling, transcription factor EB, cathelicidins, inflammation, endoplasmic reticulum stress, and autophagy-related genes. A further understanding of these mechanisms will facilitate the development of host-directed therapies against tuberculosis as well as infections with other intracellular bacteria targeted by autophagic degradation.
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Affiliation(s)
- Prashanta Silwal
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, South Korea
- Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, South Korea
| | - Seungwha Paik
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, South Korea
- Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, South Korea
| | - Jin Kyung Kim
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, South Korea
- Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, South Korea
| | - Tamotsu Yoshimori
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka, Japan
- Department of Intracellular Membrane Dynamics, Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Eun-Kyeong Jo
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, South Korea
- Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, South Korea
- *Correspondence: Eun-Kyeong Jo,
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18
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Mironov T, Sabaneyeva E. A Robust Symbiotic Relationship Between the Ciliate Paramecium multimicronucleatum and the Bacterium Ca. Trichorickettsia Mobilis. Front Microbiol 2020; 11:603335. [PMID: 33324385 PMCID: PMC7721670 DOI: 10.3389/fmicb.2020.603335] [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: 09/06/2020] [Accepted: 10/28/2020] [Indexed: 12/22/2022] Open
Abstract
Close reciprocal interactions in symbiotic systems have suggested the holobiont concept, in which the host and its microbiota are considered as a single entity. Ciliates are known for their ability to form symbiotic associations with prokaryotes. Relationships between the partners in such systems vary from mutualism to parasitism and differ significantly in their robustness. We assessed the viability of the ciliate Paramecium multimicronucleatum and its ability to maintain its intranuclear endosymbiont Ca. Trichorickettsia mobilis (Rickettsiaceae) after treatment with antibiotics characterized by different mode of action, such as ampicillin, streptomycin, chloramphenicol, tetracycline. The presence of endosymbionts in the host cell was determined by means of living cell observations made using differential interference contrast or fluorescence in situ hybridization with the species-specific oligonucleotide probe (FISH). Administration of antibiotics traditionally used in treatments of rickettsioses, tetracycline and chloramphenicol, depending on the concentration used and the ciliate strain treated, either caused death of both, infected and control cells, or did not affect the ability of the host to maintain the intranuclear endosymbiont. The surviving cells always manifested motile bacteria in the macronucleus. Streptomycin treatment never led to the loss of endosymbionts in any of the four infected strains, and nearly all ciliates remained viable. Ampicillin treatment never caused host cell death, but resulted in formation of filamentous and immobile oval bacterial forms. Under repeated ampicillin treatments, a part of endosymbionts was registered in the host cytoplasm, as evidenced both by FISH and transmission electron microscopy. Endosymbionts located in the host cytoplasm were enclosed in vacuoles, apparently, corresponding to autophagosomes. Nevertheless, the bacteria seemed to persist in this compartment and might cause relapse of the infection. Although the antibiotic sensitivity profile of Trichorickettsia seems to resemble that of other representatives of Rickettsiaceae, causative agents of severe diseases in humans, neither of the antibiotic treatments used in this study resulted in an aposymbiotic cell line, apparently, due to the protists’ sensitivity to tetracyclines, the drugs of preference in rickettsiosis treatment. The observed robustness of this symbiotic system makes it a good model for further elaboration of the holobiont concept.
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Affiliation(s)
- Timofey Mironov
- Department of Cytology and Histology, Biological Faculty, Saint-Petersburg State University, Saint-Petersburg, Russia
| | - Elena Sabaneyeva
- Department of Cytology and Histology, Biological Faculty, Saint-Petersburg State University, Saint-Petersburg, Russia
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19
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Kim JK, Silwal P, Jo EK. Host-Pathogen Dialogues in Autophagy, Apoptosis, and Necrosis during Mycobacterial Infection. Immune Netw 2020; 20:e37. [PMID: 33163245 PMCID: PMC7609165 DOI: 10.4110/in.2020.20.e37] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/15/2020] [Accepted: 10/15/2020] [Indexed: 12/11/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) is an etiologic pathogen of human tuberculosis (TB), a serious infectious disease with high morbidity and mortality. In addition, the threat of drug resistance in anti-TB therapy is of global concern. Despite this, it remains urgent to research for understanding the molecular nature of dynamic interactions between host and pathogens during TB infection. While Mtb evasion from phagolysosomal acidification is a well-known virulence mechanism, the molecular events to promote intracellular parasitism remains elusive. To combat intracellular Mtb infection, several defensive processes, including autophagy and apoptosis, are activated. In addition, Mtb-ingested phagocytes trigger inflammation, and undergo necrotic cell death, potentially harmful responses in case of uncontrolled pathological condition. In this review, we focus on Mtb evasion from phagosomal acidification, and Mtb interaction with host autophagy, apoptosis, and necrosis. Elucidation of the molecular dialogue will shed light on Mtb pathogenesis, host defense, and development of new paradigms of therapeutics.
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Affiliation(s)
- Jin Kyung Kim
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, Korea.,Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, Korea
| | - Prashanta Silwal
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, Korea.,Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, Korea
| | - Eun-Kyeong Jo
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, Korea.,Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, Korea
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20
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Jiao Y, Zhang YG, Lin Z, Lu R, Xia Y, Meng C, Pan Z, Xu X, Jiao X, Sun J. Salmonella Enteritidis Effector AvrA Suppresses Autophagy by Reducing Beclin-1 Protein. Front Immunol 2020; 11:686. [PMID: 32362899 PMCID: PMC7181453 DOI: 10.3389/fimmu.2020.00686] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 03/26/2020] [Indexed: 12/20/2022] Open
Abstract
Autophagy is a cellular process to clear pathogens. Salmonella enterica serovar Enteritidis (S.E) has emerged as one of the most important food-borne pathogens. However, major studies still focus on Salmonella enterica serovar Typhimurium. Here, we reported that AvrA, a S. Enteritidis effector, inhibited autophagy to promote bacterial survival in the host. We found that AvrA regulates the conversion of LC3 I into LC3 II and the enrichment of lysosomes. Beclin-1, a key molecular regulator of autophagy, was decreased after AvrA expressed strain colonization. In S.E-AvrA--infected cells, we found the increases of protein levels of p-JNK and p-c-Jun and the transcription level of AP-1. AvrA-reduction of Beclin-1 protein expression is through the JNK pathway. The JNK inhibitor abolished the AvrA-reduced Beclin-1 protein expression. Moreover, we identified that the AvrA mutation C186A abolished its regulation of Beclin-1 expression. In addition AvrA protein was found interacted with Beclin-1. In organoids and infected mice, we explored the physiologically related effects and mechanism of AvrA in reducing Beclin-1 through the JNK pathway, thus attenuating autophagic responses. This finding not only indicates an important role of S. Enteritidis effector in reducing host protein as a strategy to suppress autophagy, but also suggests manipulating autophagy as a new strategy to treat infectious diseases.
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Affiliation(s)
- Yang Jiao
- Division of Gastroenterology and Hepatology, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Yong-guo Zhang
- Division of Gastroenterology and Hepatology, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Zhijie Lin
- Division of Gastroenterology and Hepatology, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Rong Lu
- Division of Gastroenterology and Hepatology, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Yinglin Xia
- Division of Gastroenterology and Hepatology, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Chuang Meng
- Division of Gastroenterology and Hepatology, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Zhimin Pan
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China
| | - Xiulong Xu
- Department of Anatomy and Cell Biology, Rush University, Chicago, IL, United States
| | - Xinan Jiao
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China
| | - Jun Sun
- Division of Gastroenterology and Hepatology, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
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21
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Brothers KM, Stella NA, Shanks RMQ. Biologically active pigment and ShlA cytolysin of Serratia marcescens induce autophagy in a human ocular surface cell line. BMC Ophthalmol 2020; 20:120. [PMID: 32216768 PMCID: PMC7098141 DOI: 10.1186/s12886-020-01387-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 03/12/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The cellular process of autophagy is essential for maintaining the health of ocular tissue. Dysregulation of autophagy is associated with several ocular diseases including keratoconus and macular degeneration. It is known that autophagy can be used to respond to microbial infections and that certain microbes can exploit the autophagic process to their benefit. In this study, a genetic approach was used to identify surface-associated and secreted products generated by the opportunistic pathogen Serratia marcescens involved in activation of autophagy. METHODS A recombinant human corneal limbal epithelial cell line expressing a LC3-GFP fusion protein was challenged with normalized secretomes from wild-type and mutant S. marcescens derivatives. LC3-GFP fluorescence patterns were used to assess the ability of wild-type and mutant bacteria to influence autophagy. Purified prodigiosin was obtained from stationary phase bacteria and used to challenge ocular cells. RESULTS Mutations in the global regulators eepR and gumB genes highly reduced the ability of the bacteria to activate autophagy in corneal cells. This effect was further narrowed down to the secreted cytolysin ShlA and the biologically active pigment prodigiosin. Purified prodigiosin and ShlA from Escherichia coli further supported the role of these factors in activating autophagy in human corneal cells. Additional genetic data indicate a role for flagellin and type I pili, but not the nuclease, S-layer protein, or serratamolide biosurfactant in activation of autophagy. CONCLUSIONS This work identifies specific bacterial components that activate autophagy and give insight into potential host-pathogen interactions or compounds that can be used to therapeutically manipulate autophagy.
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Affiliation(s)
- Kimberly M Brothers
- The Charles T. Campbell Ophthalmic Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh School of Medicine, EEI 1020, 203 Lothrop Street, Pittsburgh, Pennsylvania, 15213, USA
| | - Nicholas A Stella
- The Charles T. Campbell Ophthalmic Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh School of Medicine, EEI 1020, 203 Lothrop Street, Pittsburgh, Pennsylvania, 15213, USA
| | - Robert M Q Shanks
- The Charles T. Campbell Ophthalmic Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh School of Medicine, EEI 1020, 203 Lothrop Street, Pittsburgh, Pennsylvania, 15213, USA.
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