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Kanjanapruthipong T, Sukphopetch P, Reamtong O, Isarangkul D, Muangkaew W, Thiangtrongjit T, Sansurin N, Fongsodsri K, Ampawong S. Cytoskeletal Alteration Is an Early Cellular Response in Pulmonary Epithelium Infected with Aspergillus fumigatus Rather than Scedosporium apiospermum. Microb Ecol 2022; 83:216-235. [PMID: 33890146 DOI: 10.1007/s00248-021-01750-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 04/02/2021] [Indexed: 06/12/2023]
Abstract
Invasive aspergillosis and scedosporiosis are life-threatening fungal infections with similar clinical manifestations in immunocompromised patients. Contrarily, Scedosporium apiospermum is susceptible to some azole derivative but often resistant to amphotericin B. Histopathological examination alone cannot diagnose these two fungal species. Pathogenesis studies could contribute to explore candidate protein markers for new diagnosis and treatment methods leading to a decrease in mortality. In the present study, proteomics was conducted to identify significantly altered proteins in A549 cells infected with or without Aspergillus fumigatus and S. apiospermum as measured at initial invasion. Protein validation was performed with immunogold labelling alongside immunohistochemical techniques in infected A549 cells and lungs from murine models. Further, cytokine production was measured, using the Bio-Plex-Multiplex immunoassay. The cytoskeletal proteins HSPA9, PA2G4, VAT1, PSMA2, PEX1, PTGES3, KRT1, KRT9, CLIP1 and CLEC20A were mainly changed during A. fumigatus infection, while the immunologically activated proteins WNT7A, GAPDH and ANXA2 were principally altered during S. apiospermum infection. These proteins are involved in fungal internalisation and structural destruction leading to pulmonary disorders. Interleukin (IL)-21, IL-1α, IL-22, IL-2, IL-8, IL-12, IL-17A, interferon-γ and tumour necrosis factor-α were upregulated in both aspergillosis and scedosporiosis, although more predominately in the latter, in accordance with chitin synthase-1 and matrix metalloproteinase levels. Our results demonstrated that during invasion, A. fumigatus primarily altered host cellular integrity, whereas S. apiospermum chiefly induced and extensively modulated host immune responses.
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Affiliation(s)
- Tapanee Kanjanapruthipong
- Department of Tropical Pathology, Faculty of Tropical Medicine, Mahidol University, Ratchawithi Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Passanesh Sukphopetch
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Ratchawithi Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Onrapak Reamtong
- Department of Molecular Tropical Medicine and Genetic, Faculty of Tropical Medicine, Mahidol University, Ratchawithi Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Duangnate Isarangkul
- Department of Microbiology, Faculty of Science, Mahidol University, 272, Rama VI Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Watcharamat Muangkaew
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Ratchawithi Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Tipparat Thiangtrongjit
- Department of Molecular Tropical Medicine and Genetic, Faculty of Tropical Medicine, Mahidol University, Ratchawithi Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Nichapa Sansurin
- Northeast Laboratory Animal Center, Khon Kaen University, Khon Kaen, 40002, Thailand
| | - Kamonpan Fongsodsri
- Department of Tropical Pathology, Faculty of Tropical Medicine, Mahidol University, Ratchawithi Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Sumate Ampawong
- Department of Tropical Pathology, Faculty of Tropical Medicine, Mahidol University, Ratchawithi Road, Ratchathewi, Bangkok, 10400, Thailand.
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Baranov MV, Kumar M, Sacanna S, Thutupalli S, van den Bogaart G. Modulation of Immune Responses by Particle Size and Shape. Front Immunol 2021; 11:607945. [PMID: 33679696 PMCID: PMC7927956 DOI: 10.3389/fimmu.2020.607945] [Citation(s) in RCA: 93] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 12/23/2020] [Indexed: 12/12/2022] Open
Abstract
The immune system has to cope with a wide range of irregularly shaped pathogens that can actively move (e.g., by flagella) and also dynamically remodel their shape (e.g., transition from yeast-shaped to hyphal fungi). The goal of this review is to draw general conclusions of how the size and geometry of a pathogen affect its uptake and processing by phagocytes of the immune system. We compared both theoretical and experimental studies with different cells, model particles, and pathogenic microbes (particularly fungi) showing that particle size, shape, rigidity, and surface roughness are important parameters for cellular uptake and subsequent immune responses, particularly inflammasome activation and T cell activation. Understanding how the physical properties of particles affect immune responses can aid the design of better vaccines.
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Affiliation(s)
- Maksim V. Baranov
- Department of Molecular Immunology and Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Manoj Kumar
- Simons Center for the Study of Living Machines, National Centre for Biological Sciences, Tata Institute for Fundamental Research, Bangalore, India
| | - Stefano Sacanna
- Molecular Design Institute, Department of Chemistry, New York University, New York, NY, United States
| | - Shashi Thutupalli
- Simons Center for the Study of Living Machines, National Centre for Biological Sciences, Tata Institute for Fundamental Research, Bangalore, India
- International Centre for Theoretical Sciences, Tata Institute for Fundamental Research, Bangalore, India
| | - Geert van den Bogaart
- Department of Molecular Immunology and Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
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Kidaj D, Krysa M, Susniak K, Matys J, Komaniecka I, Sroka-Bartnicka A. Biological activity of Nod factors. Acta Biochim Pol 2020; 67:435-440. [PMID: 33090749 DOI: 10.18388/abp.2020_5353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 07/01/2020] [Indexed: 11/10/2022]
Abstract
Chemically, the Nod factors (NFs) are lipochitooligosaccharides, produced mainly by bacteria of the Rhizobium genus. They are the main signaling molecules involved in the initiation of symbiosis between rhizobia and legume plants. Nod factors affect plant tissues at very low concentrations, even as low as 10-12 mol/L. They induce root hair deformation, cortical cell division, and root nodules' formation in the host plant. At the molecular level, the cytoskeleton is reorganized and expression of genes encoding proteins called nodulins is induced in response to Nod factors in the cell. Action of Nod factors is highly specific because it depends on the structure of a particular Nod factor involved, as well as the plant receptor reacting with it.
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Affiliation(s)
- Dominika Kidaj
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin, Poland
| | - Mikolaj Krysa
- Department of Biopharmacy, Medical University of Lublin, Chodzki 4a, 20-093 Lublin, Poland
| | - Katarzyna Susniak
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin, Poland
| | - Joanna Matys
- Department of Biopharmacy, Medical University of Lublin, Chodzki 4a, 20-093 Lublin, Poland
| | - Iwona Komaniecka
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin, Poland
| | - Anna Sroka-Bartnicka
- 1Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Maria Curie-Sklodowska University, Lublin, Poland; 2Department of Biopharmacy, Medical University of Lublin, Lublin, Poland
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Engelhardt S, Trutzenberg A, Hückelhoven R. Regulation and Functions of ROP GTPases in Plant-Microbe Interactions. Cells 2020; 9:E2016. [PMID: 32887298 PMCID: PMC7565977 DOI: 10.3390/cells9092016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 08/28/2020] [Accepted: 08/31/2020] [Indexed: 02/07/2023] Open
Abstract
Rho proteins of plants (ROPs) form a specific clade of Rho GTPases, which are involved in either plant immunity or susceptibility to diseases. They are intensively studied in grass host plants, in which ROPs are signaling hubs downstream of both cell surface immune receptor kinases and intracellular nucleotide-binding leucine-rich repeat receptors, which activate major branches of plant immune signaling. Additionally, invasive fungal pathogens may co-opt the function of ROPs for manipulation of the cytoskeleton, cell invasion and host cell developmental reprogramming, which promote pathogenic colonization. Strikingly, mammalian bacterial pathogens also initiate both effector-triggered susceptibility for cell invasion and effector-triggered immunity via Rho GTPases. In this review, we summarize central concepts of Rho signaling in disease and immunity of plants and briefly compare them to important findings in the mammalian research field. We focus on Rho activation, downstream signaling and cellular reorganization under control of Rho proteins involved in disease progression and pathogen resistance.
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Affiliation(s)
| | | | - Ralph Hückelhoven
- Phytopathology, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Emil-Ramann-Straße 2, 85354 Freising, Germany; (S.E.); (A.T.)
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Rahmani A, Corre E, Richard G, Bidault A, Lambert C, Oliveira L, Thompson C, Thompson F, Pichereau V, Paillard C. Transcriptomic analysis of clam extrapallial fluids reveals immunity and cytoskeleton alterations in the first week of Brown Ring Disease development. Fish Shellfish Immunol 2019; 93:940-948. [PMID: 31419531 DOI: 10.1016/j.fsi.2019.08.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 08/09/2019] [Accepted: 08/10/2019] [Indexed: 02/05/2023]
Abstract
The Brown Ring Disease is an infection caused by the bacterium Vibrio tapetis on the Manila clam Ruditapes philippinarum. The process of infection, in the extrapallial fluids (EPFs) of clams, involves alteration of immune functions, in particular on hemocytes which are the cells responsible of phagocytosis. Disorganization of the actin-cytoskeleton in infected clams is a part of what leads to this alteration. This study is the first transcriptomic approach based on collection of extrapallial fluids on living animals experimentally infected by V. tapetis. We performed differential gene expression analysis of EPFs in two experimental treatments (healthy-against infected-clams by V. tapetis), and showed the deregulation of 135 genes. In infected clams, a downregulation of transcripts implied in immune functions (lysosomal activity and complement- and lectin-dependent PRR pathways) was observed during infection. We also showed a deregulation of transcripts encoding proteins involved in the actin cytoskeleton organization such as an overexpression of β12-Thymosin (which is an actin sequestration protein) or a downregulation of proteins that closely interact with capping proteins such as Coactosin, that counteract action of capping proteins, or Profilin. We validated these transcriptomic results by cellular physiological analyses that showed a decrease of the lysosome amounts and the disorganization of actin cytoskeleton in infected hemocytes.
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Affiliation(s)
- Alexandra Rahmani
- Univ Brest, CNRS, IRD, Ifremer, UMR 6539 LEMAR, F-29280, Plouzane, France.
| | - Erwan Corre
- Sorbonne Universités, Université Pierre et Marie Curie-Paris 6, CNRS, FR2424, Station Biologique de Roscoff, Roscoff, France
| | - Gaëlle Richard
- Univ Brest, CNRS, IRD, Ifremer, UMR 6539 LEMAR, F-29280, Plouzane, France
| | - Adeline Bidault
- Univ Brest, CNRS, IRD, Ifremer, UMR 6539 LEMAR, F-29280, Plouzane, France
| | - Christophe Lambert
- Univ Brest, CNRS, IRD, Ifremer, UMR 6539 LEMAR, F-29280, Plouzane, France
| | - Louisi Oliveira
- Centro de Ciências da Saúde, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Cristiane Thompson
- Centro de Ciências da Saúde, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fabiano Thompson
- Centro de Ciências da Saúde, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Vianney Pichereau
- Univ Brest, CNRS, IRD, Ifremer, UMR 6539 LEMAR, F-29280, Plouzane, France.
| | - Christine Paillard
- Univ Brest, CNRS, IRD, Ifremer, UMR 6539 LEMAR, F-29280, Plouzane, France.
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Morrow KA, Frank DW, Balczon R, Stevens T. The Pseudomonas aeruginosa Exoenzyme Y: A Promiscuous Nucleotidyl Cyclase Edema Factor and Virulence Determinant. Handb Exp Pharmacol 2016; 238:67-85. [PMID: 28181005 DOI: 10.1007/164_2016_5003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Exoenzyme Y (ExoY) was identified as a component of the Pseudomonas aeruginosa type 3 secretion system secretome in 1998. It is a common contributor to the arsenal of type 3 secretion system effectors, as it is present in approximately 90% of Pseudomonas isolates. ExoY has adenylyl cyclase activity that is dependent upon its association with a host cell cofactor. However, recent evidence indicates that ExoY is not just an adenylyl cyclase; rather, it is a promiscuous cyclase capable of generating purine and pyrimidine cyclic nucleotide monophosphates. ExoY's enzymatic activity causes a characteristic rounding of mammalian cells, due to microtubule breakdown. In endothelium, this cell rounding disrupts cell-to-cell junctions, leading to loss of barrier integrity and an increase in tissue edema. Microtubule breakdown seems to depend upon tau phosphorylation, where the elevation of cyclic nucleotide monophosphates activates protein kinases A and G and causes phosphorylation of endothelial microtubule associated protein tau. Phosphorylation is a stimulus for tau release from microtubules, leading to microtubule instability. Phosphorylated tau accumulates inside endothelium as a high molecular weight, oligomeric form, and is then released from the cell. Extracellular high molecular weight tau causes a transmissible cytotoxicity that significantly hinders cellular repair following infection. Thus, ExoY may contribute to bacterial virulence in at least two ways; first, by microtubule breakdown leading to loss of endothelial cell barrier integrity, and second, by promoting release of a high molecular weight tau cytotoxin that impairs cellular recovery following infection.
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Affiliation(s)
- K Adam Morrow
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, AL, 36688, USA
- The Center for Lung Biology, University of South Alabama, Mobile, AL, 36688, USA
| | - Dara W Frank
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
- Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Ron Balczon
- The Center for Lung Biology, University of South Alabama, Mobile, AL, 36688, USA
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL, 36688, USA
| | - Troy Stevens
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, AL, 36688, USA.
- The Center for Lung Biology, University of South Alabama, Mobile, AL, 36688, USA.
- Department of Medicine, University of South Alabama, Mobile, AL, 36688, USA.
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Vu K, Eigenheer RA, Phinney BS, Gelli A. Cryptococcus neoformans promotes its transmigration into the central nervous system by inducing molecular and cellular changes in brain endothelial cells. Infect Immun 2013; 81:3139-47. [PMID: 23774597 PMCID: PMC3754227 DOI: 10.1128/iai.00554-13] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 06/07/2013] [Indexed: 12/31/2022] Open
Abstract
Cryptococcus spp. cause fungal meningitis, a life-threatening infection that occurs predominately in immunocompromised individuals. In order for Cryptococcus neoformans to invade the central nervous system (CNS), it must first penetrate the brain endothelium, also known as the blood-brain barrier (BBB). Despite the importance of the interrelation between C. neoformans and the brain endothelium in establishing CNS infection, very little is known about this microenvironment. Here we sought to resolve the cellular and molecular basis that defines the fungal-BBB interface during cryptococcal attachment to, and internalization by, the human brain endothelium. In order to accomplish this by a systems-wide approach, the proteomic profile of human brain endothelial cells challenged with C. neoformans was resolved using a label-free differential quantitative mass spectrometry method known as spectral counting (SC). Here, we demonstrate that as brain endothelial cells associate with, and internalize, cryptococci, they upregulate the expression of several proteins involved with cytoskeleton, metabolism, signaling, and inflammation, suggesting that they are actively signaling and undergoing cytoskeleton remodeling via annexin A2, S100A10, transgelin, and myosin. Transmission electronic microscopy (TEM) analysis demonstrates dramatic structural changes in nuclei, mitochondria, the endoplasmic reticulum (ER), and the plasma membrane that are indicative of cell stress and cell damage. The translocation of HMGB1, a marker of cell injury, the downregulation of proteins that function in transcription, energy production, protein processing, and the upregulation of cyclophilin A further support the notion that C. neoformans elicits changes in brain endothelial cells that facilitate the migration of cryptococci across the BBB and ultimately induce endothelial cell necrosis.
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Affiliation(s)
- Kiem Vu
- Department of Pharmacology, School of Medicine, University of California, Genome and Biomedical Sciences Facility, Davis, California, USA
| | - Richard A. Eigenheer
- Proteomics Core Facility, University of California, Genome Center, Davis, California, USA
| | - Brett S. Phinney
- Proteomics Core Facility, University of California, Genome Center, Davis, California, USA
| | - Angie Gelli
- Department of Pharmacology, School of Medicine, University of California, Genome and Biomedical Sciences Facility, Davis, California, USA
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Chin E, Kirker K, Zuck M, James G, Hybiske K. Actin recruitment to the Chlamydia inclusion is spatiotemporally regulated by a mechanism that requires host and bacterial factors. PLoS One 2012; 7:e46949. [PMID: 23071671 PMCID: PMC3469565 DOI: 10.1371/journal.pone.0046949] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 09/07/2012] [Indexed: 11/18/2022] Open
Abstract
The ability to exit host cells at the end of their developmental growth is a critical step for the intracellular bacterium Chlamydia. One exit strategy, extrusion, is mediated by host signaling pathways involved with actin polymerization. Here, we show that actin is recruited to the chlamydial inclusion as a late event, occurring after 20 hours post-infection (hpi) and only within a subpopulation of cells. This event increases significantly in prevalence and extent from 20 to 68 hpi, and actin coats strongly correlated with extrusions. In contrast to what has been reported for other intracellular pathogens, actin nucleation on Chlamydia inclusions did not 'flash', but rather exhibited moderate depolymerization dynamics. By using small molecule agents to selectively disrupt host signaling pathways involved with actin nucleation, modulate actin polymerization dynamics and also to disable the synthesis and secretion of chlamydial proteins, we further show that host and bacterial proteins are required for actin coat formation. Transient disruption of either host or bacterial signaling pathways resulted in rapid loss of coats in all infected cells and a reduction in extrusion formation. Inhibition of Chlamydia type III secretion also resulted in rapid loss of actin association on inclusions, thus implicating chlamydial effector proteins(s) as being central factors for engaging with host actin nucleating factors, such as formins. In conclusion, our data illuminate the host and bacterial driven process by which a dense actin matrix is dynamically nucleated and maintained on the Chlamydia inclusion. This late stage event is not ubiquitous for all infected cells in a population, and escalates in prevalence and extent throughout the developmental cycle of Chlamydia, culminating with their exit from the host cell by extrusion. The initiation of actin recruitment by Chlamydia appears to be novel, and may serve as an upstream determinant of the extrusion mechanism.
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Affiliation(s)
- Elizabeth Chin
- Division of Infectious Diseases, School of Public Health, University of California at Berkeley, California, United States of America
| | - Kelly Kirker
- Center for Biofilm Engineering, Montana State University, Bozeman, Montana, United States of America
| | - Meghan Zuck
- Division of Infectious Diseases, School of Public Health, University of California at Berkeley, California, United States of America
| | - Garth James
- Center for Biofilm Engineering, Montana State University, Bozeman, Montana, United States of America
| | - Kevin Hybiske
- Division of Infectious Diseases, School of Public Health, University of California at Berkeley, California, United States of America
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Brulle F, Jeffroy F, Madec S, Nicolas JL, Paillard C. Transcriptomic analysis of Ruditapes philippinarum hemocytes reveals cytoskeleton disruption after in vitro Vibrio tapetis challenge. Dev Comp Immunol 2012; 38:368-76. [PMID: 22450167 DOI: 10.1016/j.dci.2012.03.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 02/28/2012] [Accepted: 03/06/2012] [Indexed: 02/08/2023]
Abstract
The Manila clam, Ruditapes philippinarum, is an economically-important, commercial shellfish; harvests are diminished in some European waters by a pathogenic bacterium, Vibrio tapetis, that causes Brown Ring disease. To identify molecular characteristics associated with susceptibility or resistance to Brown Ring disease, Suppression Subtractive Hybridization (SSH) analyzes were performed to construct cDNA libraries enriched in up- or down-regulated transcripts from clam immune cells, hemocytes, after a 3-h in vitro challenge with cultured V. tapetis. Nine hundred and ninety eight sequences from the two libraries were sequenced, and an in silico analysis identified 235 unique genes. BLAST and "Gene ontology" classification analyzes revealed that 60.4% of the Expressed Sequence Tags (ESTs) have high similarities with genes involved in various physiological functions, such as immunity, apoptosis and cytoskeleton organization; whereas, 39.6% remain unidentified. From the 235 unique genes, we selected 22 candidates based upon physiological function and redundancy in the libraries. Then, Real-Time PCR analysis identified 3 genes related to cytoskeleton organization showing significant variation in expression attributable to V. tapetis exposure. Disruption in regulation of these genes is consistent with the etiologic agent of Brown Ring disease in Manila clams.
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Affiliation(s)
- Franck Brulle
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR CNRS 6539, IUEM, Technopole Brest-Iroise, 29280 Plouzané, France
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Abstract
Fungal pathologies are seen in immunocompromised and healthy humans. C-type lectins expressed on immature dendritic cells (DC) recognize fungi. We report a novel dorsal pseudopodial protrusion, the “fungipod”, formed by DC after contact with yeast cell walls. These structures have a convoluted cell-proximal end and a smooth distal end. They persist for hours, exhibit noticeable growth and total 13.7±5.6 µm long and 1.8±0.67 µm wide at the contact. Fungipods contain clathrin and an actin core surrounded by a sheath of cortactin. The actin cytoskeleton, but not microtubules, is required for fungipod integrity and growth. An apparent rearward flow (225±55 nm/second) exists from the zymosan contact site into the distal fungipod. The phagocytic receptor Dectin-1 is not required for fungipod formation, but CD206 (Mannose Receptor) is the generative receptor for these protrusions. The human pathogen Candida parapsilosis induces DC fungipod formation strongly, but the response is species specific since the related fungal pathogens Candida tropicalis and Candida albicans induce very few and no fungipods, respectively. Our findings show that fungipods are dynamic actin-driven cellular structures involved in fungal recognition by DC. They may promote yeast particle phagocytosis by DC and are a specific response to large (i.e., 5 µm) particulate ligands. Our work also highlights the importance of this novel protrusive structure to innate immune recognition of medically significant Candida yeasts in a species specific fashion. Yeasts are normal microbial commensals of humans and a significant source of opportunistic infections, especially in immunocompromised individuals. We report a novel cellular protrusive structure, the fungipod, which participates in the host-microbe interaction between human immature dendritic cells (DC) and yeasts. The fungipod's structure is based on and propelled by a robust process of local actin cytoskeleton growth at the DC-yeast contact site, and this cytoskeletal remodeling results in a durable tubular structure over 10 µm long connecting the dorsal DC membrane and yeast. The fungal cell wall polysaccharides mannan and chitin trigger fungipod formation by stimulating the carbohydrate pattern recognition receptor CD206. Fungipods are part of a specific response to large particulate objects (i.e., yeast), and they may promote the human immature DC's relatively poor phagocytosis of yeast. The human fungal pathogen, Candida parapsilosis, induces a strong fungipod response from DC, and this response is highly species specific since the related pathogens Candida albicans and Candida tropicalis induce fungipods rarely. Our work highlights a novel cell biological element of fungal recognition by the innate immune system.
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Affiliation(s)
- Aaron K. Neumann
- Department of Cell & Developmental Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Ken Jacobson
- Department of Cell & Developmental Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail:
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Pielage JF, Powell KR, Kalman D, Engel JN. RNAi screen reveals an Abl kinase-dependent host cell pathway involved in Pseudomonas aeruginosa internalization. PLoS Pathog 2008; 4:e1000031. [PMID: 18369477 PMCID: PMC2265438 DOI: 10.1371/journal.ppat.1000031] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Accepted: 02/21/2008] [Indexed: 01/13/2023] Open
Abstract
Internalization of the pathogenic bacterium Pseudomonas aeruginosa by non-phagocytic cells is promoted by rearrangements of the actin cytoskeleton, but the host pathways usurped by this bacterium are not clearly understood. We used RNAi-mediated gene inactivation of ∼80 genes known to regulate the actin cytoskeleton in Drosophila S2 cells to identify host molecules essential for entry of P. aeruginosa. This work revealed Abl tyrosine kinase, the adaptor protein Crk, the small GTPases Rac1 and Cdc42, and p21-activated kinase as components of a host signaling pathway that leads to internalization of P. aeruginosa. Using a variety of complementary approaches, we validated the role of this pathway in mammalian cells. Remarkably, ExoS and ExoT, type III secreted toxins of P. aeruginosa, target this pathway by interfering with GTPase function and, in the case of ExoT, by abrogating P. aeruginosa–induced Abl-dependent Crk phosphorylation. Altogether, this work reveals that P. aeruginosa utilizes the Abl pathway for entering host cells and reveals unexpected complexity by which the P. aeruginosa type III secretion system modulates this internalization pathway. Our results furthermore demonstrate the applicability of using RNAi screens to identify host signaling cascades usurped by microbial pathogens that may be potential targets for novel therapies directed against treatment of antibiotic-resistant infections. Mortality from Pseudomonas aeruginosa infections, one of the leading causes of hospital acquired infections, approaches 40%, and multiple drug resistant infections are common and increasing. Internalization of P. aeruginosa by the host cell appears to play a fundamental role in the pathogenesis of this opportunistic bacterium, but the host cell factors involved in this process are incompletely understood. We used a targeted RNAi screen in Drosophila S2 cells to identify a subset of regulators of the host actin cytoskeleton that contribute to bacterial entry and confirmed their involvement in infection of mammalian cells. We found that P. aeruginosa can modulate this internalization pathway in a complex manner by injecting the bacterial toxins ExoS and ExoT into the host cell via its type III secretion system. The identified host cell molecules may serve as targets for novel drugs to treat infections resistant to conventional antibiotics and may be applicable to a wide range of pathogens.
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Affiliation(s)
- Julia F. Pielage
- Program in Microbial Pathogenesis and Host Defense, University of California San Francisco, San Francisco, California, United States of America
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Department of Microbiology & Immunology, University of California San Francisco, San Francisco, California, United States of America
| | - Kimberly R. Powell
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Daniel Kalman
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Joanne N. Engel
- Program in Microbial Pathogenesis and Host Defense, University of California San Francisco, San Francisco, California, United States of America
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Department of Microbiology & Immunology, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
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12
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Gutiérrez-Venegas G, Kawasaki-Cárdenas P, Garcés CP, Román-Alvárez P, Barajas-Torres C, Contreras-Marmolejo LA. Actinobacillus actinomycetemcomitans adheres to human gingival fibroblasts and modifies cytoskeletal organization. Cell Biol Int 2007; 31:1063-8. [PMID: 17500015 DOI: 10.1016/j.cellbi.2007.03.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2006] [Revised: 01/19/2007] [Accepted: 03/21/2007] [Indexed: 11/21/2022]
Abstract
Adherence of Actinobacillus actinomycetemcomitans to human gingival fibroblast cells induces cytoskeletal reorganization. A. actinomycetemcomitans is considered a pathogenic bacteria involved in localized aggressive periodontitis. Studies with epithelial cells have shown an adherent capacity of bacteria that is increased under anaerobic conditions. For adherence to take place, there is a need for interaction between extracellular vesicles and bacterial fimbriae. However, molecular events associated with the adherence process are still unknown. The aim of this study was to investigate whether A. actinomycetemcomitans adherence to human gingival fibroblasts promotes cytoskeletal reorganization. Adherence was determined with light microscopy and scanning electron microscopy. For F-actin visualization, cells were treated with fluorescein-isothiocyanate-phalloidin and samples were examined with epifluorescence optics. Fluorescent was recorded on Kodak T-Max 400 film. We showed that A. actinomycetemcomitans adheres to human gingival fibroblast primary cultures, this property stimulating an increase in the intracellular calcium levels. In human gingival fibroblast primary cultures, we observed that maximal A. actinomycetemcomitans adherence took place 1.5h after culture infection occurred and remained for 6h. The adherence was associated with morphologic alterations and an increased in the intracellular calcium levels. These experiments suggest that A. actinomycetemcomitans adherence cause morphological alterations, induce actin stress fibers and recruitment of intracellular calcium levels.
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Affiliation(s)
- Gloria Gutiérrez-Venegas
- Laboratorio de Bioquímica, División de Estudios de Posgrado de la Facultad de Odontología, Universidad Nacional Autónoma de México, Circuito Universitario, 04510 Mexico D.F., Mexico.
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13
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Abstract
To infect host cells, Salmonella utilizes an intricate system to manipulate the actin cytoskeleton and promote bacterial uptake. Proteins injected into the host cell by Salmonella activate the Rho GTPases, Rac1 and Cdc42, to induce actin polymerization. Following uptake, a different set of proteins inactivates Rac1 and Cdc42, returning the cytoskeleton to normal. Although the signaling pathways allowing Salmonella to invade host cells are beginning to be understood, many of the contributing factors remain to be elucidated. IQGAP1 is a multidomain protein that influences numerous cellular functions, including modulation of Rac1/Cdc42 signaling and actin polymerization. Here, we report that IQGAP1 regulates Salmonella invasion. Through its interaction with actin, IQGAP1 co-localizes with Rac1, Cdc42, and actin at sites of bacterial uptake, whereas infection promotes the interaction of IQGAP1 with both Rac1 and Cdc42. Knockdown of IQGAP1 significantly reduces Salmonella invasion and abrogates activation of Cdc42 and Rac1 by Salmonella. Overexpression of IQGAP1 significantly increases the ability of Salmonella to enter host cells and required interaction with both actin and Cdc42/Rac1. Together, these data identify IQGAP1 as a novel regulator of Salmonella invasion.
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Affiliation(s)
- Matthew D Brown
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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14
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Okamoto K, Kanoe M, Yaguchi Y, Watanabe T, Inoue T. Effects of the collagenolytic cell wall component of Fusobacterium necrophorum subsp. necrophorum on bovine hepatocytes. Res Vet Sci 2007; 82:166-8. [PMID: 17275045 DOI: 10.1016/j.rvsc.2006.01.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2005] [Revised: 04/04/2005] [Accepted: 01/09/2006] [Indexed: 11/29/2022]
Abstract
The effects of the collagenolytic cell wall component (CCWC) of Fusobacterium necrophorum subsp. necrophorum on bovine hepatic cell and cytoskeletons were investigated. Scanning electron microscopy (SEM) demonstrated that CCWC damaged the cell surfaces, forming tiny holes on the cell membranes. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) profiles revealed that CCWC degraded bovine cytokeratin and vimentin and by indirect fluorescent antibody (IFA) method, it was shown that CCWC caused the deformation of hepatocellular vimentin. This suggested that CCWC contributes to bovine hepatic injury and it may be as important pathogenic factor in the development of bovine hepatic abscesses.
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Affiliation(s)
- K Okamoto
- Laboratory of Animal Health, Tokyo University of Agriculture, 1737 Funako, Atsugi, Kanagawa 243-0034, Japan.
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15
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Abstract
Shigella flexneri, the causative agent of bacillary dysentery, injects invasin proteins through a type III secretion apparatus upon contacting the host cell, which triggers pathogen internalization. The invasin IpaA is essential for S. flexneri pathogenesis and binds to the cytoskeletal protein vinculin to facilitate host cell entry. We report that IpaA harbors two vinculin-binding sites (VBSs) within its C-terminal domain that bind to and activate vinculin in a mutually exclusive fashion. Only the highest affinity C-terminal IpaA VBS is necessary for efficient entry and cell–cell spread of S. flexneri, whereas the lower affinity VBS appears to contribute to vinculin recruitment at entry foci of the pathogen. Finally, the crystal structures of vinculin in complex with the VBSs of IpaA reveal the mechanism by which IpaA subverts vinculin's functions, where S. flexneri utilizes a remarkable level of molecular mimicry of the talin–vinculin interaction to activate vinculin. Mimicry of vinculin's interactions may therefore be a general mechanism applied by pathogens to infect the host cell.
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Affiliation(s)
- Tina Izard
- Cell Adhesion Laboratory, Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
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16
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López V, Suárez M, Chico-Calero I, Navas J, Martínez-Suárez JV. [Foodborne Listeria monocytogenes: are all the isolates equally virulent?]. Rev Argent Microbiol 2006; 38:224-34. [PMID: 17370579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023] Open
Abstract
Listeria monocytogenes is a foodborne human pathogen responsible for invasive infections presenting overall a high mortality. Despite the ubiquity of the microorganism, the actual disease rate is quite low and the disease is most often associated with an underlying predisposition. Foodborne and environmental isolates were traditionally considered of similar pathogenicity compared to clinical isolates. But the analysis of mutations in the genes encoding specific virulence factors (internalin, hemolysin, phospholipases, surface protein ActA and regulator protein PrfA), quantitative studies with cell cultures and population genetics have raised considerable concerns about virulence differences among L. monocytogenes strains. Despite this great step forward, there is not a single marker available to test the virulence of field isolates of this species. In the future, the combination of different molecular markers will probably allow the screening of food contamination by only the virulent clones of L. monocytogenes, thus improving the prevention of foodborne human listeriosis.
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Affiliation(s)
- V López
- Departamento de Tecnología de Alimentos, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Carretera de La Coruña km 7'5, 28040 Madrid, España
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17
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Shin S, Paul-Satyaseela M, Maneesh PS, Lee JS, Romer LH, Kim KS. Focal adhesion kinase is involved in type III group B streptococcal invasion of human brain microvascular endothelial cells. Microb Pathog 2006; 41:168-73. [PMID: 16949788 DOI: 10.1016/j.micpath.2006.07.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2005] [Revised: 06/08/2006] [Accepted: 07/07/2006] [Indexed: 11/26/2022]
Abstract
Group B streptococcus (GBS), the leading cause of neonatal meningitis, has been shown to invade human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier. GBS invasion of HBMEC has been shown to require the host cell actin cytoskeleton rearrangements. The present study examined the mechanisms underlying actin cytoskeleton rearrangements that are involved in type III GBS invasion of HBMEC. We showed that type III GBS invasion was inhibited by genistein, a general tyrosine kinase inhibitor (mean 54% invasion decrease at 100 microM), and LY294002, a phosphatidylinositol 3 (PI3) kinase inhibitor (mean 70% invasion decrease at 50 microM), but not by PP2, an inhibitor of the Src family tyrosine kinases. We subsequently showed that the focal adhesion kinase (FAK) was the one of the host proteins tyrosine phosphorylated by type III GBS. Over-expression of a dominant negative form of the FAK C-terminal domain significantly decreased type III GBS invasion of HBMEC (mean 51% invasion decrease). In addition, we showed that FAK phosphorylation correlated with its association of paxillin, an adapter protein of actin filament, and PI3-kinase subunit p85. This is the first demonstration that FAK phosphorylation and its association with paxillin and PI3 kinase play a key role in type III GBS invasion of HBMEC.
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Affiliation(s)
- Sooan Shin
- Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Park 256, Baltimore, MD 21287, USA
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18
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Cortez M, Atayde V, Yoshida N. Host cell invasion mediated by Trypanosoma cruzi surface molecule gp82 is associated with F-actin disassembly and is inhibited by enteroinvasive Escherichia coli. Microbes Infect 2006; 8:1502-12. [PMID: 16697683 DOI: 10.1016/j.micinf.2006.01.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2005] [Revised: 12/13/2005] [Accepted: 01/06/2006] [Indexed: 01/21/2023]
Abstract
The target cell F-actin disassembly, induced by a Ca2+-signaling Trypanosoma cruzi factor of unknown molecular identity, has been reported to promote parasite invasion. We investigated whether the metacyclic trypomastigote stage-specific surface molecule gp82, a Ca2+-signal-inducing molecule implicated in host cell invasion, displayed the ability to induce actin cytoskeleton disruption, using a recombinant protein (J18) containing the full-length gp82 sequence fused to GST. J18, but not GST, induced F-actin disassembly in HeLa cells, significantly reducing the number as well as the length of stress fibers. The number of cells with typical stress fibers scored approximately 70% in untreated and GST-treated cells, as opposed to approximately 30% in J18-treated samples, which also showed decreased F-actin content. J18, but not GST, inhibited approximately 6-fold the HeLa cell entry of enteroinvasive Escherichia coli (EIEC), which depends on actin cytoskeleton. Not only were fewer cells infected with bacteria in the presence of J18, there were also fewer bacteria per cell. The inhibitory activity of J18 was Ca2+ dependent. In co-infection experiments, preincubation of HeLa cells with EIEC drastically reduced gp82-dependent internalization of T. cruzi metacyclic forms. All these data, plus the finding that gp82-mediated penetration of metacyclic forms was associated with disrupted HeLa cell cytoskeletal architecture, indicate that gp82 promotes parasite invasion by disassembling the cortical actin cytoskeleton.
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Affiliation(s)
- Mauro Cortez
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, R. Botucatu, 862, 6th andar, 04023-062 São Paulo, Brazil
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19
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Vlisidou I, Dziva F, La Ragione RM, Best A, Garmendia J, Hawes P, Monaghan P, Cawthraw SA, Frankel G, Woodward MJ, Stevens MP. Role of intimin-tir interactions and the tir-cytoskeleton coupling protein in the colonization of calves and lambs by Escherichia coli O157:H7. Infect Immun 2006; 74:758-64. [PMID: 16369035 PMCID: PMC1346653 DOI: 10.1128/iai.74.1.758-764.2006] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Intimin facilitates intestinal colonization by enterohemorrhagic Escherichia coli O157:H7; however, the importance of intimin binding to its translocated receptor (Tir) as opposed to cellular coreceptors is unknown. The intimin-Tir interaction is needed for optimal actin assembly under adherent bacteria in vitro, a process which requires the Tir-cytoskeleton coupling protein (TccP/EspF(U)) in E. coli O157:H7. Here we report that E. coli O157:H7 tir mutants are at least as attenuated as isogenic eae mutants in calves and lambs, implying that the role of intimin in the colonization of reservoir hosts can be explained largely by its binding to Tir. Mutation of tccP uncoupled actin assembly from the intimin-Tir-mediated adherence of E. coli O157:H7 in vitro but did not impair intestinal colonization in calves and lambs, implying that pedestal formation may not be necessary for persistence. However, an E. coli O157:H7 tccP mutant induced typical attaching and effacing lesions in a bovine ligated ileal loop model of infection, suggesting that TccP-independent mechanisms of actin assembly may operate in vivo.
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Affiliation(s)
- Isabella Vlisidou
- Institute for Animal Health, High Street, Compton, Berkshire RG20 7NN, United Kingdom
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20
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Abstract
Porphyromonas gingivalis, an important periodontal pathogen, is an effective colonizer of oral tissues. The organism successfully invades, multiplies in, and survives for extended periods in primary gingival epithelial cells (GECs). It is unknown whether P. gingivalis resides in the cytoplasm of infected cells throughout the infection or can spread to adjacent cells over time. We developed a technique based on flow cytofluorometry and fluorescence microscopy to study propagation of the organism at different stages of infection of GECs. Results showed that P. gingivalis spreads cell to cell and that the amount of spreading increases gradually over time. There was a very low level of propagation of bacteria to uninfected cells early in the infection (3 h postinfection), but there were 20-fold and 45-fold increases in the propagation rate after 24 h and 48 h, respectively, of infection. Immunofluorescence microscopy of infected cells suggested that intercellular translocation of P. gingivalis may be mediated through actin-based membrane protrusions, bypassing the need for release of bacteria into extracellular medium. Consistent with these observations, cytochalasin D treatment of infected cells resulted in significant inhibition of bacterial spreading. This study shows for the first time that P. gingivalis disseminates from cell to cell without passing through the extracellular space. This mechanism of spreading may allow P. gingivalis to colonize oral tissues without exposure to the humoral immune response.
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Affiliation(s)
- Ozlem Yilmaz
- Department of Pathobiology, University of Washington, Box 357 238, Seattle, WA 98195, USA.
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21
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Nazli A, Wang A, Steen O, Prescott D, Lu J, Perdue MH, Söderholm JD, Sherman PM, McKay DM. Enterocyte cytoskeleton changes are crucial for enhanced translocation of nonpathogenic Escherichia coli across metabolically stressed gut epithelia. Infect Immun 2006; 74:192-201. [PMID: 16368973 PMCID: PMC1346602 DOI: 10.1128/iai.74.1.192-201.2006] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Substantial data implicate the commensal flora as triggers for the initiation of enteric inflammation or inflammatory disease relapse. We have shown that enteric epithelia under metabolic stress respond to nonpathogenic bacteria by increases in epithelial paracellular permeability and bacterial translocation. Here we assessed the structural basis of these findings. Confluent filter-grown monolayers of the human colonic T84 epithelial cell line were treated with 0.1 mM dinitrophenol (which uncouples oxidative phosphorylation) and noninvasive, nonpathogenic Escherichia coli (strain HB101, 10(6) CFU) with or without pretreatment with various pharmacological agents. At 24 h later, apoptosis, tight-junction protein expression, transepithelial resistance (TER; a marker of paracellular permeability), and bacterial internalization and translocation were assessed. Treatment with stabilizers of microtubules (i.e., colchicine), microfilaments (i.e., jasplakinolide) and clathrin-coated pit endocytosis (i.e., phenylarsine oxide) all failed to block DNP+E. coli HB101-induced reductions in TER but effectively prevented bacterial internalization and translocation. Neither the TER defect nor the enhanced bacterial translocations were a consequence of increased apoptosis. These data show that epithelial paracellular and transcellular (i.e., bacterial internalization) permeation pathways are controlled by different mechanisms. Thus, epithelia under metabolic stress increase their endocytotic activity that can result in a microtubule-, microfilament-dependent internalization and transcytosis of bacteria. We speculate that similar events in vivo would allow excess unprocessed antigen and bacteria into the mucosa and could evoke an inflammatory response by, for example, the activation of resident or recruited immune cells.
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Affiliation(s)
- Aisha Nazli
- Intestinal Disease Research Programme, HSC-3N5C, McMaster University, 1200 Main Street West, Hamilton, Ontario L8N 3Z5, Canada
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22
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Marjomäki V, Schaible UE. Microbial strategies to exploit host cells. Meeting on spatial and temporal dynamics of the endomembrane system. EMBO Rep 2005; 6:408-12. [PMID: 15864291 PMCID: PMC1299315 DOI: 10.1038/sj.embor.7400409] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2005] [Accepted: 03/23/2005] [Indexed: 01/22/2023] Open
Affiliation(s)
- Varpu Marjomäki
- University of Jyväskylä, Nanoscience Center, Department of Biological and Environmental Science, Ambiotica C2, Survontie 9, FIN-40500 Jyväskylä, Finland
| | - Ulrich E. Schaible
- Max-Planck-Institute of Infection Biology, Department of Immunology, Schumannstrasse 21/22, D-10117 Berlin, Germany
- Tel: +49 030 28460575; Fax: +49 030 28460503;
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23
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Abstract
Many bacterial pathogens manipulate the host cell cytoskeleton during infection. Such cytoskeletal modulation can occur at several points of contact between the pathogen and the host, and involves extracellular receptors, intracellular signal transduction and cytoskeletal proteins themselves. The field of bacterial pathogenesis has progressed dramatically over the past decade, such that structural knowledge is both timely and essential for a full appreciation of the biology at the pathogen-host interface. Several recent examples involving bacterial proteins that target actin, Rho family GTPases and extracellular receptors have contributed to a structural understanding of eukaryotic cytoskeletal modulation by pathogens.
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Affiliation(s)
- C Erec Stebbins
- Laboratory of Structural Microbiology, Rockefeller University, New York, New York 10021, USA.
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24
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Abstract
Deciphering how Listeria monocytogenes exploits the host cell machinery to invade mammalian cells during infection isa key issue for the understanding how this food-borne pathogen causes a pleiotropic disease ranging from gastro-enteritis to meningitis and abortions. Using multidisciplinary approaches, essentially combining bacterial genetics and cell biology, we have identified two bacterial proteins critical for entry into target cells, InlA and InlB. Their cellular ligands have been also identified: InlA interacts with the adhesion molecule E-cadherin, while InlB interacts with the receptor for the globular head of the complement factor Clq (gClq-R), with the hepatocyte growth factor receptor (c-Met) and with glycosaminoglycans(including heparan sulphate). The dynamic interaction between these cellular receptors and the actin cytoskeleton is currently under investigation. Several intracellular molecules have been recognized as key effectors for Listeria entry into target cells,including catenins (implicated in the connection of E-cadherin to actin) and the actin depolymerising factor/cofilin (involved in the rearrangement of the cytoskeleton in the InlB-dependent internalisation pathway). At the organism level, species specificity has been discovered concerning the interaction between InlA and E-cadherin, leading to the generation of transgenic mice expressing the human E-cadherin, in which the critical role of InlA in the crossing of the intestinal barrier has been clearly determined. Listeria appears as an instrumental model for addressing critical questions concerning both the complex process of bacterial pathogenesis and also fundamental molecular processes, such as phagocytosis.
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Affiliation(s)
- Javier Pizarro-Cerdá
- Unité des interaction bactéries-cellules, Départment Biologie Cellulaire et Infection, Institut Pasteur, Paris, France
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25
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Mendes-Giannini MJS, Hanna SA, da Silva JLM, Andreotti PF, Vincenzi LR, Benard G, Lenzi HL, Soares CP. Invasion of epithelial mammalian cells by Paracoccidioides brasiliensis leads to cytoskeletal rearrangement and apoptosis of the host cell. Microbes Infect 2004; 6:882-91. [PMID: 15310464 DOI: 10.1016/j.micinf.2004.05.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2003] [Accepted: 05/11/2004] [Indexed: 11/26/2022]
Abstract
Paracoccidioides brasiliensis (Pb) yeast cells can enter mammalian cells and probably manipulate the host cell environment to favor their own growth and survival. We studied the uptake of strain Pb 18 into A549 lung and Vero epithelial cells, with an emphasis on the repercussions in the cytoskeleton and the apoptosis of host cells. Cytoskeleton components of the host cells, such as actin and tubulin, were involved in the P. brasiliensis invasion process. Cytochalasin D and colchicine treatment substantially reduced invasion, indicating the functional participation of microfilaments (MFs) and microtubules (MTs) in this mechanism. Cytokeratin could also play a role in the P. brasiliensis interaction with the host. Gp43 was recognized by anti-actin and anti-cytokeratin antibodies, but not by anti-tubulin. The apoptosis induced by this fungus in infected epithelial cells was demonstrated by various techniques: TUNEL, DNA fragmentation and Bak and Bcl-2 immunocytochemical expression. DNA fragmentation was observed in infected cells but not in uninfected ones, by both TUNEL and gel electrophoresis methods. Moreover, Bcl-2 and Bak did not show any differences until 24 h after infection of cells, suggesting a competitive mechanism that allows persistence of infection. Overexpression of Bak was observed after 48 h, indicating the loss of competition between death and survival signals. In conclusion, the mechanisms of invasion of host cells, persistence within them, and the subsequent induction of apoptosis of such cells may explain the efficient dissemination of P. brasiliensis.
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Affiliation(s)
- Maria José Soares Mendes-Giannini
- Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas-UNESP, Rua Expedicionários do Brasil, 1621-CEP, 14801-902 Araraquara, SP, Brazil.
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26
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Abstract
Rickettsia conorii, the causative agent of Mediterranean spotted fever, is able to attach to and invade a variety of cell types both in vitro and in vivo. Although previous studies show that entry of R. conorii into non-phagocytic cells relies on actin polymerization, little else is known about the molecular details governing Rickettsia-host cell interactions and actin rearrangements. We determined that R. conorii recruits the Arp2/3 complex to the site of entry foci and that expression of an Arp 2/3 binding derivative of the WASP-family member, Scar, inhibited bacterial entry into Vero cells, establishing that Arp2/3 is an active component of this process. Using transient transfection with plasmids expressing dominant negative versions of small GTPases, we showed that Cdc42, but not Rac1 is involved in R. conorii invasion into Vero cells. Using pharmacological approaches, we show that this invasion is dependent on phosphoinositide (PI) 3-kinase and on protein tyrosine kinase (PTK) activities, in particular Src-family kinases. C-Src and its downstream target, p80/85 cortactin, colocalize at entry sites early in the infection process. R. conorii internalization correlated with the tyrosine phosphorylation of several other host proteins, including focal adhesion kinase (FAK), within minutes of R. conorii infection. Our results reveal that R. conorii entry into nonphagocytic cells is dependent on the Arp2/3 complex and that the interplay of pathways involving Cdc42, PI 3-kinase, c-Src, cortactin and tyrosine-phosphorylated proteins regulates Arp2/3 activation leading to the localized actin rearrangements observed during bacterial entry. This is the first report that documents the mechanism of entry of a rickettsial species into mammalian cells.
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Affiliation(s)
- Juan J Martinez
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, INSERM U604, Département de Biologie Cellulaire et Infection, 25 Rue du Dr Roux, 75724 Paris CEDEX 15, France
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27
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Alonso A, García-del Portillo F. Hijacking of eukaryotic functions by intracellular bacterial pathogens. Int Microbiol 2004; 7:181-91. [PMID: 15492932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Intracellular bacterial pathogens have evolved as a group of microorganisms endowed with weapons to hijack many biological processes of eukaryotic cells. This review discusses how these pathogens perturb diverse host cell functions, such as cytoskeleton dynamics and organelle vesicular trafficking. Alteration of the cytoskeleton is discussed in the context of the bacterial entry process (invasion), which occurs either by activation of membrane-located host receptors ("zipper" mechanism) or by injection of bacterial proteins into the host cell cytosol ("trigger" mechanism). In addition, the two major types of intracellular lifestyles, cytosolic versus intravacuolar (phagosomal), which are the consequence of alterations in the phagosome-lysosome maturation route, are compared. Specific examples illustrating known mechanisms of mimicry or hijacking of the host target are provided. Finally, recent advances in phagosome proteomics and genome expression in intracellular bacteria are described. These new technologies are yielding valuable clues as to how these specialized bacterial pathogens manipulate the mammalian host cell.
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Affiliation(s)
- Ana Alonso
- Department of Microbial Biotechnology, National Center for Biotechnology, CSIC, Madrid, Spain
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28
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Abstract
Some bacterial pathogens enter mammalian cells by injecting, directly into the host cytosol, proteins that trigger cytoskeletal rearrangements necessary for internalization. In the February 27 issue of Molecular Cell, McGhie et al. identify mechanisms by which the Salmonella protein SipA interferes with ADF/cofilin and gelsolin function. Thus Salmonella not only triggers actin polymerization but also counteracts the major F-actin destabilizing proteins.
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Affiliation(s)
- Pascale Cossart
- Unité des Interactions Bactéries Cellules, Institut Pasteur, 28 Rue du Docteur Roux, INSERM U604, Paris 75015, France
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29
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Abstract
Intracellular bacterial pathogens have evolved mechanisms to enter and exit eukaryotic cells using the power of actin polymerisation and to subvert the activity of cellular enzymes and signal transduction pathways. The proteins deployed by bacteria to subvert cellular processes often mimic eukaryotic proteins in their structure or function. Studies on the exploitation of host cells by the facultative intracellular pathogen Burkholderia pseudomallei are providing novel insights into the pathogenesis of melioidosis, a serious invasive disease of animals and humans that is endemic in tropical and subtropical areas. B. pseudomallei can invade epithelial cells, survive and proliferate inside phagocytes, escape from endocytic vesicles, form actin-based membrane protrusions and induce host cell fusion. Here we review current understanding of the molecular mechanisms underlying these processes.
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Affiliation(s)
- Mark P Stevens
- Division of Microbiology, Institute for Animal Health, Compton Laboratory, Berkshire, United Kingdom
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30
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Abstract
Helicobacter pylori causes host epithelial cell cytoskeletal rearrangements mediated by the translocation and tyrosine phosphorylation of an outer-membrane protein, CagA, and by the vacuolating cytotoxin, VacA. However, the mechanisms by which H. pylori mediates cytoskeletal rearrangements in infected host cells need to be more clearly defined. The aim of this study was to determine the effects of H. pylori isolates from children on the architecture of host gastric epithelial cells. Gastric epithelial (AGS) cells were infected with type I (cagE(+), cagA(+), VacA(+)) H. pylori, a type II H. pylori strain (cagE(-), cagA(-), VacA(-)) or a cagE isogenic mutant. Double-labelled immune fluorescence was used to detect adherent H. pylori and the distribution of F-actin, alpha-actinin and Arp3. Both type I and type II H. pylori strains induced stress fibres in gastric epithelial cells that were not observed in uninfected cells. Type I H. pylori also induced cell elongation (hummingbird phenotype) after 4 h of infection, whereas the type II H. pylori strain did not. Less elongation occurred when AGS cells were exposed to a cagE isogenic mutant, compared with the parental strain. Confocal microscopy showed Arp3 accumulation in AGS cells infected with wild-type H. pylori, but not in response to infection with the cagE mutant. These findings indicate that type I H. pylori induce a stress fibre-like phenotype in infected gastric epithelia by a mechanism that is different from the induction of host-cell elongation. In addition to CagA and VacA, cagE also impacts on the morphology of infected gastric epithelial cells.
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Affiliation(s)
- Bin Su
- Research Institute, Hospital for Sick Children, Departments of Paediatrics and Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada M5G 1X8
| | - Peter J M Ceponis
- Research Institute, Hospital for Sick Children, Departments of Paediatrics and Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada M5G 1X8
| | - Philip M Sherman
- Research Institute, Hospital for Sick Children, Departments of Paediatrics and Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada M5G 1X8
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31
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Abstract
Pathogenic microbes subvert normal host-cell processes to create a specialized niche, which enhances their survival. A common and recurring target of pathogens is the host cell's cytoskeleton, which is utilized by these microbes for purposes that include attachment, entry into cells, movement within and between cells, vacuole formation and remodelling, and avoidance of phagocytosis. Our increased understanding of these processes in recent years has not only contributed to a greater comprehension of the molecular causes of infectious diseases, but has also revealed fundamental insights into normal functions of the cytoskeleton. From the use of bacterial toxins to investigate Rho family GTPases to in vitro studies of actin polymerization using Listeria and Shigella, the study of pathogenesis has provided important tools to probe cytoskeletal function.
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Affiliation(s)
- Samantha Gruenheid
- Biotechnology Laboratory, University of British Columbia, Vancouver, Canada V6T 1Z3
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32
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Fiorentini C, Falzano L, Travaglione S, Fabbri A. Hijacking Rho GTPases by protein toxins and apoptosis: molecular strategies of pathogenic bacteria. Cell Death Differ 2003; 10:147-52. [PMID: 12700642 DOI: 10.1038/sj.cdd.4401151] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Certain bacterial toxins and type-III-translocated virulence factors have a peculiar property: they exert part of their actions by modulating Rho GTPases. These toxins target the actin cytoskeleton of host cells and reorganize it to their own advantage, either to facilitate macropinocytosis, which is required for invasive bacteria to enter cells, or to block pathogen sequestration by macrophages. In addition, by acting on Rho GTPases, bacteria may also interfere with the fate of host cells, favoring survival or death depending on their needs. Rho GTPases control the activation of NF-kappaB, which is involved in the expression of antiapoptotic proteins and mediates immunological responses as well. Here, we give a perspective on how NF-kappaB may participate in linking Rho-acting toxins and apoptosis.
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Affiliation(s)
- C Fiorentini
- Department of Ultrastructures, Istituto Superiore di Sanitá, Viale Regina Elena, Rome, Italy.
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33
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Carabeo RA, Grieshaber SS, Fischer E, Hackstadt T. Chlamydia trachomatis induces remodeling of the actin cytoskeleton during attachment and entry into HeLa cells. Infect Immun 2002; 70:3793-803. [PMID: 12065523 PMCID: PMC128046 DOI: 10.1128/iai.70.7.3793-3803.2002] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
To elucidate the host cell machinery utilized by Chlamydia trachomatis to invade epithelial cells, we examined the role of the actin cytoskeleton in the internalization of chlamydial elementary bodies (EBs). Treatment of HeLa cells with cytochalasin D markedly inhibited the internalization of C. trachomatis serovar L2 and D EBs. Association of EBs with HeLa cells induced localized actin polymerization at the site of attachment, as visualized by either phalloidin staining of fixed cells or the active recruitment of GFP-actin in viable infected cells. The recruitment of actin to the specific site of attachment was accompanied by dramatic changes in the morphology of cell surface microvilli. Ultrastructural studies revealed a transient microvillar hypertrophy that was dependent upon C. trachomatis attachment, mediated by structural components on the EBs, and cytochalasin D sensitive. In addition, a mutant CHO cell line that does not support entry of C. trachomatis serovar L2 did not display such microvillar hypertrophy following exposure to L2 EBs, which is in contrast to infection with serovar D, to which it is susceptible. We propose that C. trachomatis entry is facilitated by an active actin remodeling process that is induced by the attachment of this pathogen, resulting in distinct microvillar reorganization throughout the cell surface and the formation of a pedestal-like structure at the immediate site of attachment and entry.
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Affiliation(s)
- Reynaldo A Carabeo
- Host-Parasite Interactions Section, Laboratory of Intracellular Parasites, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, USA
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34
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Kenny B, Ellis S, Leard AD, Warawa J, Mellor H, Jepson MA. Co-ordinate regulation of distinct host cell signalling pathways by multifunctional enteropathogenic Escherichia coli effector molecules. Mol Microbiol 2002; 44:1095-1107. [PMID: 12046591 DOI: 10.1046/j.1365-2958.2002.02952.x] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Enteropathogenic Escherichia coli (EPEC) is a major cause of paediatric diarrhoea and a model for the family of attaching and effacing (A/E) pathogens. A/E pathogens encode a type III secretion system to transfer effector proteins into host cells. The EPEC Tir effector protein acts as a receptor for the bacterial surface protein intimin and is involved in the formation of Cdc42-independent, actin-rich pedestal structures beneath the adhered bacteria. In this paper, we demonstrate that EPEC binding to HeLa cells also induces Tir-independent, cytoskeletal rearrangement evidenced by the early, transient formation of filopodia-like structures at sites of infection. Filopodia formation is dependent on expression of the EPEC Map effector molecule - a protein that targets mitochondria and induces their dysfunction. We show that Map-induced filopodia formation is independent of mitochondrial targeting and is abolished by cellular expression of the Cdc42 inhibitory WASP-CRIB domain, demonstrating that Map has at least two distinct functions in host cells. The transient nature of the filopodia is related to an ability of EPEC to downregulate Map-induced cell signalling that, like pedestal formation, was dependent on both Tir and intimin proteins. The ability of Tir to downregulate filopodia was impaired by disrupting a putative GTPase-activating protein (GAP) motif, suggesting that Tir may possess such a function, with its interaction with intimin triggering this activity. Furthermore, we also found that Map-induced cell signalling inhibits pedestal formation, revealing that the cellular effects of Tir and Map must be co-ordinately regulated during infection. Possible implications of the multifunctional nature of EPEC effector molecules in pathogenesis are discussed.
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Affiliation(s)
- Brendan Kenny
- Departmentof Pathology and Microbiology, School of Medical Sciences, University Walk, Bristol, UK.
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35
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Abstract
Bacterial enteric infections exact a heavy toll on the human population, particularly among children. Despite the explosion of knowledge on the pathogenesis of enteric diseases experienced during the past decade, the number of diarrhoeal episodes and human deaths reported worldwide remains of apocalyptic dimensions. However, our better understanding of the pathogenic mechanisms involved in the onset of diarrhoea is finally leading to preventive interventions, such as the development of enteric vaccines, that may have a significant impact on the magnitude of this human plague. The application of a multidisciplinary approach to study bacterial pathogenesis, along with the recent sequencing of entire microbial genomes, have made possible discoveries that are changing the way scientists view the bacterium-host interaction. Today, research on the molecular basis of the pathogenesis of infective diarrhoeal diseases of necessity transcends established boundaries between microbiology, cell biology, intestinal pathophysiology, and immunology. This review focuses on the most recent outcomes of this multidisciplinary effort.
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Affiliation(s)
- A Fasano
- Division of Pediatric Gastroenterology and Nutrition, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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36
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Genre A, Bonfante P. Epidermal cells of a symbiosis-defective mutant of Lotus japonicus show altered cytoskeleton organisation in the presence of a mycorrhizal fungus. Protoplasma 2002; 219:43-50. [PMID: 11926066 DOI: 10.1007/s007090200004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The influence of the mycorrhizal fungus Gigaspora margarita on cytoskeleton organisation in epidermal cells of Lotus japonicus roots was compared between plants of the wild type Gifu and the mutant Ljsym4-2, in which the fungus is confined to the epidermal cells. Immunofluorescence labelling of plant microtubules and microfilaments showed only limited alterations in the peripheral cytoskeleton of epidermal cells during early stages of fungal interaction with the wild type. Later, microtubules and microfilaments enveloped the growing hypha, while the host cell nucleus moved close to the fungus. In contrast, epidermal cells of the mutant responded with disorganisation and disassembly of microtubules and microfilaments before and during fungal penetration attempts. The fungus penetrated only as far as to epidermal cells, whose cytoplasm became devoid of tubulin and actin, suggesting cell death. The close relationship between host cytoskeleton organisation and compatibility with the fungus suggests that a functional Ljsym4 gene is necessary for correct reorganisation of the epidermal cell cytoskeleton in the presence of the fungus and for avoiding hypersensitivity-like reactions.
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Affiliation(s)
- A Genre
- Dipartimento di Biologia Vegetale, Università di Torino, Centro di Studio sulla Micologia del Terreno, Consiglio Nazionale delle Ricerche, Torino, Italy
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37
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Abstract
The bacterial pathogen Salmonella enterica has evolved a very sophisticated functional interface with its vertebrate hosts. At the center of this interface is a specialized organelle, the type III secretion system, that directs the translocation of bacterial proteins into the host cell. Salmonella spp. encode two such systems that deliver a remarkable array of bacterial proteins capable of modulating a variety of cellular functions, including actin cytoskeleton dynamics, nuclear responses, and endocytic trafficking. Many of these bacterial proteins operate by faithful mimicry of host proteins, in some cases representing the result of extensive molecular tinkering and convergent evolution. The coordinated action of these type III secreted proteins secures the replication and survival of the bacteria avoiding overt damage to the host. The study of this remarkable pathogen is not only illuminating general paradigms in microbial pathogenesis but is also providing valuable insight into host cell functions.
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Affiliation(s)
- J E Galán
- Section of Microbial Pathogenesis, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut 06536, USA.
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38
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Zhou D. Collective efforts to modulate the host actin cytoskeleton by Salmonella type III-secreted effector proteins. Trends Microbiol 2001; 9:567-9; discussion 569-70. [PMID: 11728859 DOI: 10.1016/s0966-842x(01)02227-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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39
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Abstract
Upon contact with intestinal epithelial cells, Salmonella enterica serovar spp. inject a set of bacterial proteins into host cells via the bacterial SPI-1 type III secretion system. SopE, SopE2 and SopB, activate CDC42 and Rac to initiate actin cytoskeleton rearrangements. SipA and SipC, two Salmonella actin-binding proteins, directly modulate host actin dynamics to facilitate bacterial uptake. SptP promotes the recovery of the actin cytoskeleton rearrangements by antagonizing CDC42 and Rac. Therefore, Salmonella-induced reversible actin cytoskeleton rearrangements are the result of two coordinated steps: (i) stimulation of host signal transduction to indirectly promote actin rearrangements and (ii) direct modulation of actin dynamics.
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Affiliation(s)
- D Zhou
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA.
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40
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Fernandez IM, Silva M, Schuch R, Walker WA, Siber AM, Maurelli AT, McCormick BA. Cadaverine prevents the escape of Shigella flexneri from the phagolysosome: a connection between bacterial dissemination and neutrophil transepithelial signaling. J Infect Dis 2001; 184:743-53. [PMID: 11517436 DOI: 10.1086/323035] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2001] [Revised: 06/01/2001] [Indexed: 11/04/2022] Open
Abstract
Shigella flexneri causes bacillary dysentery in humans by invading epithelial cells of the colon, which is characterized by an acute polymorphonuclear leukocyte (PMNL)-rich inflammation. Our recent studies demonstrated that cadaverine, a polyamine, specifically acts to abrogate transepithelial signaling to PMNL induced by S. flexneri. Here, insight is provided into the cellular mechanisms by which cadaverine attenuates the ability of Shigella species to induce PMNL signaling. It was found that cadaverine retards the lysis of the Shigella species-containing vacuole, suggesting that a blockade is established, in which the pathogen is prevented from adequately interacting with the cytoskeleton. Furthermore, an IcsA mutant of S. flexneri that cannot interact with the cytoskeleton and spreads intercellularly fails to induce transmigration of PMNL. Results indicate that cadaverine-induced compartmentalization of Shigella species to the phagolysosome might be a protective response of the host that directly contributes to the diminished ability of PMNL to transmigrate across model intestinal epithelia.
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Affiliation(s)
- I M Fernandez
- Mucosal Immunology Laboratories, Department of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital, Charlestown, Massachusetts 02129-4404, USA.
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41
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Abstract
A number of unrelated bacterial species as well as vaccinia virus (ab)use the process of actin polymerization to facilitate and enhance their infection cycle. Studies into the mechanism by which these pathogens hijack and control the actin cytoskeleton have provided many interesting insights into the regulation of actin polymerization in migrating cells. This review focuses on what we have learnt from the actin-based motilities of Listeria, Shigella and vaccinia and discusses what we would still like to learn from our nasty friends, including enteropathogenic Escherichia coli and Rickettsia
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Affiliation(s)
- F Frischknecht
- Cell Biology and Biophysics Programme, European Molecular Biology Laboratory, Meyerhofstrabetae 1, 69117, Heidelberg, Germany
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42
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Ashorn M, Cantet F, Mayo K, Megraud F. Cytoskeletal rearrangements induced by Helicobacter pylori strains in epithelial cell culture: possible role of the cytotoxin. Dig Dis Sci 2000; 45:1774-80. [PMID: 11052319 DOI: 10.1023/a:1005578110764] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The relationship between Helicobacter pylori adherence, cytotoxin production, and modification of the cytoskeletal structure was investigated by studying the effects of 12 H. pylori strains cocultured with Hep-2 epithelial cells. Bacterial strains were isolated from patients with peptic ulcer disease or nonulcer dyspepsia. Presence of the cag pathogenicity island and vacA subtypes of the strains were determined as was the production of vacuolating cytotoxin. We found that cytoskeletal rearrangements, as observed by confocal microscopy after double staining of the bacteria and the cell actin with Texas red and fluorescein-conjugated phalloidin, respectively, occurred essentially when the strains were cytotoxin producers and that the supernatants alone could also lead to these modifications.
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Affiliation(s)
- M Ashorn
- Laboratoire de Bactériologie, Université Victor Ségalen Bordeaux II, France
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43
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Abstract
Salmonella spp. have evolved the ability to enter into cells that are normally nonphagocytic. The internalization process is the result of a remarkable interaction between the bacteria and the host cells. Immediately on contact, Salmonella delivers a number of bacterial effector proteins into the host cell cytosol through the function of a specialized organelle termed the type III secretion system. Initially, two of the delivered proteins, SopE and SopB, stimulate the small GTP-binding proteins Cdc42 and Rac. SopE is an exchange factor for these GTPases, and SopB is an inositol polyphosphate phosphatase. Stimulation of Cdc42 and Rac leads to marked actin cytoskeleton rearrangements, which are further enhanced by SipA, a Salmonella protein also delivered into the host cell by the type III secretion system. SipA lowers the critical concentration of G-actin, stabilizes F-actin at the site of bacterial entry, and increases the bundling activity of the host-cell protein T-plastin (fimbrin). The cellular responses stimulated by Salmonella are short-lived; therefore, immediately after bacterial entry, the cell regains its normal architecture. Remarkably, this process is mediated by SptP, another target of the type III secretion system. SptP exert its function by serving as a GTPase-activating protein for Cdc42 and Rac, turning these G proteins off after their stimulation by the bacterial effectors SopE and SopB. The balanced interaction of Salmonella with host cells constitutes a remarkable example of the sophisticated nature of a pathogen/host relationship shaped by evolution through a longstanding coexistence.
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Affiliation(s)
- J E Galan
- Section of Microbial Pathogenesis, Boyer Center for Molecular Medicine, Yale School of Medicine, New Haven, CT 06536-0812, USA.
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44
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Abstract
The ability of the widespread avian pathogen Mycoplasma gallisepticum to invade cultured human epithelial cells (HeLa-229) and chicken embryo fibroblasts (CEF) was investigated by using the gentamicin invasion assay and a double immunofluorescence microscopic technique for accurate localization of cell-associated mycoplasmas. The presence of intracellular mycoplasmas in both cell lines was clearly demonstrated, with organisms entering the eukaryotic cells within 20 min. Internalized mycoplasmas have the ability to leave the cell, but also to survive within the intracellular space over a 48-h period. Frequencies of invasion were shown to differ between the two cell lines, but were also considerably dependent on the mycoplasma input population. Of the prototype strain R, a low-passage population in artificial medium, R(low), was capable of active cell invasion, while a high-passage population, R(high), showed adherence to but nearly no uptake into HeLa-229 and CEF. By passaging R(low) and R(high) multiple times through HeLa-229 cells, the invasion frequency was significantly increased. Taken together, these findings demonstrate that M. gallisepticum has the capability of entering nonphagocytic host cells that may provide this pathogen with the opportunity for resisting host defenses and selective antibiotic therapy, establishing chronic infections, and passing through the respiratory mucosal barrier to cause systemic infections.
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Affiliation(s)
- F Winner
- Institute of Bacteriology, Mycology and Hygiene, University of Veterinary Medicine Vienna, A-1210 Vienna, Austria
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45
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Affiliation(s)
- C F Lesser
- Depts. of Microbiology and Medicine, University of Washington, 1959 NE Pacific St, Seattle, WA 98195, USA
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46
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Scragg MA, Kelly MJ, Williams DM. Porphyromonas gingivalis induces ultrastructural and cytoskeletal changes in adherent human polymorphonuclear leucocytes. J Submicrosc Cytol Pathol 2000; 32:221-8. [PMID: 11085211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
The response of polymorphonuclear leucocytes (PMN) from healthy humans to culture supernatant from the periodontopathogen, Porphyromonas gingivalis, was examined using light, fluorescence and electron microscopy. Exposure of adherent cells to bacterial culture supernatant resulted in a 4-fold increase in the proportion of spread, flattened PMN. Scanning and transmission electron microscopy demonstrated that these cells had long dendritic cytoplasmic projections closely adherent to the substratum, in contrast with the more rounded, less adherent, control PMN. These shape changes were accompanied by a mean reduction in granule density to 57% compared with control cells (p<0.05) and a reduction in F-actin levels to 62% of controls (p<0.001), but no loss of viability and suggest a bacterially-induced mechanism of suppression of PMN motility which is likely to contribute to the pathogenic potential of P. gingivalis.
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Affiliation(s)
- M A Scragg
- Department of Oral Pathology, St. Bartholomew's and the Royal London School of Medicine and Dentistry, UK.
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47
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Affiliation(s)
- C Lammel
- Department of Laboratory Medicine, University of California, San Francisco 94143, USA.
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48
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Abstract
Some periodontal pathogens disrupt epithelial barriers and cellular adhesion to the extracellular matrix, which affects the cytoskeleton. Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans exploit the cytoskeleton during their uptake by epithelial cells. Treponema denticola perturbs actin and actin-regulating pathways in host cells. Cytoskeletal dysfunction due to pathogenic bacteria may impair physiologic remodeling and wound repair in the periodontium.
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Affiliation(s)
- R P Ellen
- University of Toronto, Faculty of Dentistry, 124 Edward Street, Toronto M5G 1G6, Canada
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49
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Skoudy A, Nhieu GT, Mantis N, Arpin M, Mounier J, Gounon P, Sansonetti P. A functional role for ezrin during Shigella flexneri entry into epithelial cells. J Cell Sci 1999; 112 ( Pt 13):2059-68. [PMID: 10362536 DOI: 10.1242/jcs.112.13.2059] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Shigella flexneri is an enteroinvasive bacterium responsible for bacillary dysentery in humans. Bacterial entry into epithelial cells is a crucial step for the establishment of the infection. It is characterized by a transient reorganization of the host cell cytoskeleton at the site of bacterial interaction with the cell membrane, which leads to bacterial engulfment by a macropinocytic process. We show in this study that the membrane-cytoskeleton linker, ezrin, a member of the ERM (ezrin, radixin, moesin) family, plays an active role in the process of Shigella uptake. Ezrin is highly enriched in cellular protrusions induced by the bacterium and is found in close association with the plasma membrane. In addition, Shigella entry is significantly reduced in cells transfected with a dominant negative allele of ezrin with entry foci showing much shorter cellular protrusions. These results indicate that ezrin not only acts as a membrane-cytoskeleton linker, but may also mediate extension of cellular projections in the presence of signals such as those elicited by invading microorganisms.
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Affiliation(s)
- A Skoudy
- Unité de Pathogénie Microbienne Moléculaire, INSERM U389, France
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50
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Dombek PE, Cue D, Sedgewick J, Lam H, Ruschkowski S, Finlay BB, Cleary PP. High-frequency intracellular invasion of epithelial cells by serotype M1 group A streptococci: M1 protein-mediated invasion and cytoskeletal rearrangements. Mol Microbiol 1999; 31:859-70. [PMID: 10048029 DOI: 10.1046/j.1365-2958.1999.01223.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A clonal variant of serotype M1 group A streptococcus (designated M1inv+) has been linked to severe and invasive infections, including sepsis, necrotizing fasciitis and toxic shock. High frequency internalization of cultured epithelial cells by the M1inv+ strain 90-226 is dependent upon the M1 protein. Invasion of HeLa cells was blocked by an anti-M1 antibody, invasion by an M1- strain (90-226 emm1::km) was greatly reduced, and latex beads bound to M1 protein were readily internalized by HeLa cells. Beads coated with a truncated M1 protein were internalized far less frequently. Scanning electron microscopy indicated that streptococci invade by a zipper-like mechanism, that may be mediated by interactions with host cell microvilli. Initially, internalized streptococci and streptococci undergoing endocytosis are associated with polymerized actin. Later in the internalization process, streptococcal-containing vacuoles are associated with the lysosomal membrane glycoprotein, LAMP-1.
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Affiliation(s)
- P E Dombek
- Department of Microbiology, University of Minnesota 55455, USA
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