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Danov A, Pollin I, Moon E, Ho M, Wilson BA, Papathanos PA, Kaplan T, Levy A. Identification of novel toxins associated with the extracellular contractile injection system using machine learning. Mol Syst Biol 2024:10.1038/s44320-024-00053-6. [PMID: 39069594 DOI: 10.1038/s44320-024-00053-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 06/06/2024] [Accepted: 06/27/2024] [Indexed: 07/30/2024] Open
Abstract
Secretion systems play a crucial role in microbe-microbe or host-microbe interactions. Among these systems, the extracellular contractile injection system (eCIS) is a unique bacterial and archaeal extracellular secretion system that injects protein toxins into target organisms. However, the specific proteins that eCISs inject into target cells and their functions remain largely unknown. Here, we developed a machine learning classifier to identify eCIS-associated toxins (EATs). The classifier combines genetic and biochemical features to identify EATs. We also developed a score for the eCIS N-terminal signal peptide to predict EAT loading. Using the classifier we classified 2,194 genes from 950 genomes as putative EATs. We validated four new EATs, EAT14-17, showing toxicity in bacterial and eukaryotic cells, and identified residues of their respective active sites that are critical for toxicity. Finally, we show that EAT14 inhibits mitogenic signaling in human cells. Our study provides insights into the diversity and functions of EATs and demonstrates machine learning capability of identifying novel toxins. The toxins can be employed in various applications dependently or independently of eCIS.
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Affiliation(s)
- Aleks Danov
- Department of Plant Pathology and Microbiology, Institute of Environmental Sciences, The Robert H. Smith Faculty of Agriculture, Food & Environment, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Inbal Pollin
- Department of Plant Pathology and Microbiology, Institute of Environmental Sciences, The Robert H. Smith Faculty of Agriculture, Food & Environment, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Eric Moon
- Department of Microbiology, University of Illinois Urbana-Champaign, 601 South Goodwin Ave, Urbana, 61801, IL, USA
| | - Mengfei Ho
- Department of Microbiology, University of Illinois Urbana-Champaign, 601 South Goodwin Ave, Urbana, 61801, IL, USA
| | - Brenda A Wilson
- Department of Microbiology, University of Illinois Urbana-Champaign, 601 South Goodwin Ave, Urbana, 61801, IL, USA
| | - Philippos A Papathanos
- Department of Entomology, Institute of Environmental Sciences, The Robert H. Smith Faculty of Agriculture, Food & Environment, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Tommy Kaplan
- School of Computer Science and Engineering, The Hebrew University of Jerusalem, Jerusalem, Israel
- Department of Developmental Biology and Cancer Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Asaf Levy
- Department of Plant Pathology and Microbiology, Institute of Environmental Sciences, The Robert H. Smith Faculty of Agriculture, Food & Environment, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel.
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Handy NB, Xu Y, Moon D, Sowizral JJ, Moon E, Ho M, Wilson BA. Hierarchical determinants in cytotoxic necrotizing factor (CNF) toxins driving Rho G-protein deamidation versus transglutamination. mBio 2024; 15:e0122124. [PMID: 38920360 PMCID: PMC11253639 DOI: 10.1128/mbio.01221-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Accepted: 05/22/2024] [Indexed: 06/27/2024] Open
Abstract
The cytotoxic necrotizing factor (CNF) family of AB-type bacterial protein toxins catalyze two types of modification on their Rho GTPase substrates: deamidation and transglutamination. It has been established that E. coli CNF1 and its close homolog proteins catalyze primarily deamidation and Bordetella dermonecrotic toxin (DNT) catalyzes primarily transglutamination. The rapidly expanding microbial genome sequencing data have revealed that there are at least 13 full-length variants of CNF1 homologs. CNFx from E. coli strain GN02091 is the most distant from all other members of the CNF family with 50%-55% sequence identity at the protein level and 0.45-0.52 nucleotide substitutions per site at the DNA level. CNFx modifies RhoA, Rac1, and Cdc42, and like CNF1, activates downstream SRE-dependent mitogenic signaling pathways in human HEK293T cells, but at a 1,000-fold higher EC50 value. Unlike other previously characterized CNF toxins, CNFx modifies Rho proteins primarily through transglutamination, as evidenced by gel-shift assay and confirmed by MALDI mass spectral analysis, when coexpressed with Rho-protein substrates in E. coli BL21 cells or through direct treatment of HEK293T cells. A comparison of CNF1 and CNFx sequences identified two critical active-site residues corresponding to positions 832 and 862 in CNF1. Reciprocal site-specific mutations at these residues in each toxin revealed hierarchical rules that define the preference for deamidase versus a transglutaminase activity in CNFs. An additional unique Cys residue at the C-terminus of CNFx was also discovered to be critical for retarding cargo delivery.IMPORTANCECytotoxic necrotizing factor (CNF) toxins not only play important virulence roles in pathogenic E. coli and other bacterial pathogens, but CNF-like genes have also been found in an expanding number of genomes from clinical isolates. Harnessing the power of evolutionary relationships among the CNF toxins enabled the deciphering of the hierarchical active-site determinants that define whether they modify their Rho GTPase substrates through deamidation or transglutamination. With our finding that a distant CNF variant (CNFx) unlike other known CNFs predominantly transglutaminates its Rho GTPase substrates, the paradigm of "CNFs deamidate and DNTs transglutaminate" could finally be attributed to two critical amino acid residues within the active site other than the previously identified catalytic Cys-His dyad residues. The significance of our approach and research findings is that they can be applied to deciphering enzyme reaction determinants and substrate specificities for other bacterial proteins in the development of precision therapeutic strategies.
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Affiliation(s)
- Nicholas B. Handy
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Yiting Xu
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Damee Moon
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Jacob J. Sowizral
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Eric Moon
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Mengfei Ho
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Brenda A. Wilson
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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Nandanwar N, Gibson JE, Neely MN. Transcriptome profiles of macrophages upon infection by morphotypic smooth and rough variants of Mycobacterium abscessus. Microbes Infect 2024; 26:105367. [PMID: 38782181 DOI: 10.1016/j.micinf.2024.105367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 05/07/2024] [Accepted: 05/17/2024] [Indexed: 05/25/2024]
Abstract
Mycobacterium abscessus (Mab) infection can be deadly in patients with chronic lung diseases like cystic fibrosis (CF). In vitro and in vivo, Mab may adopt a smooth (S) or rough (R) morphotype, the latter linked to more severe disease conditions. In vitro studies revealed differences in pathogenicity and immune response to S and R morphotypes. We propose that in vivo both morphotypes exist and may transiently switch depending on the environment, having important pathogenic and immunologic consequences. This can be modeled by morphotypic S and R variants of Mab selected based on in vitro growth conditions. Here, we report the first analysis of early transcriptional events in mouse bone marrow derived macrophages (BMDMs) upon infection with media-selected interchangeable Mab-S and Mab-R morphotypes. The early transcriptional events after infection with both morphotypes showed considerable overlap of the pro-inflammatory genes that were differentially regulated compared to the uninfected macrophages. We also observed signature genes significantly differentially regulated in macrophages during infection of media-selected morphotypic Mab-S and Mab-R variants. In conclusion, media-selected Mab-S and Mab-R behave in a similar fashion to stable S and R types with respect to pathogenesis and immune response, serving as a useful model for environmentally influenced morphotype selection.
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Affiliation(s)
- Nishant Nandanwar
- Division of Infectious Diseases, Department of Pediatrics, Children's Hospital Los Angeles, CA, 90027, USA.
| | - Joy E Gibson
- Division of Infectious Diseases, Department of Pediatrics, Children's Hospital Los Angeles, CA, 90027, USA; Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90027, USA
| | - Michael N Neely
- Division of Infectious Diseases, Department of Pediatrics, Children's Hospital Los Angeles, CA, 90027, USA; Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90027, USA
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Wong Z, Ong EBB. Unravelling bacterial virulence factors in yeast: From identification to the elucidation of their mechanisms of action. Arch Microbiol 2024; 206:303. [PMID: 38878203 DOI: 10.1007/s00203-024-04023-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 05/21/2024] [Accepted: 05/29/2024] [Indexed: 06/23/2024]
Abstract
Pathogenic bacteria employ virulence factors (VF) to establish infection and cause disease in their host. Yeasts, Saccharomyces cerevisiae and Saccharomyces pombe, are useful model organisms to study the functions of bacterial VFs and their interaction with targeted cellular processes because yeast processes and organelle structures are highly conserved and similar to higher eukaryotes. In this review, we describe the principles and applications of the yeast model for the identification and functional characterisation of bacterial VFs to investigate bacterial pathogenesis. The growth inhibition phenotype caused by the heterologous expression of bacterial VFs in yeast is commonly used to identify candidate VFs. Then, subcellular localisation patterns of bacterial VFs can provide further clues about their target molecules and functions during infection. Yeast knockout and overexpression libraries are also used to investigate VF interactions with conserved eukaryotic cell structures (e.g., cytoskeleton and plasma membrane), and cellular processes (e.g., vesicle trafficking, signalling pathways, and programmed cell death). In addition, the yeast growth inhibition phenotype is also useful for screening new drug leads that target and inhibit bacterial VFs. This review provides an updated overview of new tools, principles and applications to study bacterial VFs in yeast.
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Affiliation(s)
- ZhenPei Wong
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Penang, 11800 USM, Malaysia
| | - Eugene Boon Beng Ong
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Penang, 11800 USM, Malaysia.
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Giannuzzi D, Capra E, Bisutti V, Vanzin A, Marsan PA, Cecchinato A, Pegolo S. Methylome-wide analysis of milk somatic cells upon subclinical mastitis in dairy cattle. J Dairy Sci 2024; 107:1805-1820. [PMID: 37939836 DOI: 10.3168/jds.2023-23821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 10/18/2023] [Indexed: 11/10/2023]
Abstract
Better understanding of the molecular mechanisms behind bovine mastitis is fundamental for improving the management of this disease, which continues to be of major concern for the dairy industry, especially in its subclinical form. Disease severity and progression depend on numerous aspects, such as livestock genetics, and the interaction between the causative agent, the host, and the environment. In this context, epigenetic mechanisms have proven to have a role in controlling the response of the animal to inflammation. Therefore, in this study we aimed to explore genome-wide DNA methylation of milk somatic cells (SC) in healthy cows (n = 15) and cows affected by naturally occurring subclinical mastitis by Streptococcus agalactiae (n = 12) and Prototheca spp. (n = 11), to better understand the role of SC methylome in the host response to disease. Differentially methylated regions (DMR) were evaluated comparing: (1) Strep. agalactiae-infected versus healthy; (2) Prototheca-infected versus healthy, and (3) mastitis versus healthy and (4) Strep. agalactiae-infected versus Prototheca-infected. The functional analysis was performed at 2 levels. To begin with, we extracted differentially methylated genes (DMG) from promoter DMR, which were analyzed using the Cytoscape ClueGO plug-in. Coupled with this DMG-driven approach, all the genes associated with promoter-methylated regions were fed to the Pathifier algorithm. From the DMR analysis, we identified 1,081 hypermethylated and 361 hypomethylated promoter regions in Strep. agalactiae-infected animals, while 1,514 hypermethylated and 358 hypomethylated promoter regions were identified in Prototheca-infected animals, when compared with the healthy controls. When considering infected animals as a whole group (regardless of the pathogen), we found 1,576 hypermethylated and 460 hypomethylated promoter regions. Both pathogens were associated with methylation differences in genes involved in pathways related to meiosis, reproduction and tissue remodeling. Exploring the whole methylome, in subclinically infected cows we observed a strong deregulation of immune-related pathways, such as nuclear factor kB and toll-like receptors signaling pathways, and of energy-related pathways such as the tricarboxylic acid cycle and unsaturated fatty acid biosynthesis. In conclusion, no evident pathogen-specific SC methylome signature was detected in the present study. Overall, we observed a clear regulation of host immune response driven by DNA methylation upon subclinical mastitis. Further studies on a larger cohort of animals are needed to validate our results and to possibly identify a unique SC methylome that signifies pathogen-specific alterations.
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Affiliation(s)
- D Giannuzzi
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, 35020, Legnaro, Italy
| | - E Capra
- Institute of Agricultural Biology and Biotechnology, National Research Council (IBBA CNR), 26900, Lodi, Italy
| | - V Bisutti
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, 35020, Legnaro, Italy.
| | - A Vanzin
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, 35020, Legnaro, Italy
| | - P Ajmone Marsan
- Department of Animal Science, Food and Nutrition (DIANA), Università Cattolica del Sacro Cuore, 29122, Piacenza, Italy
| | - A Cecchinato
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, 35020, Legnaro, Italy
| | - S Pegolo
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, 35020, Legnaro, Italy
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Olney KC, de Ávila C, Todd KT, Tallant LE, Barnett JH, Gibson KA, Hota P, Pandiane AS, Durgun PC, Serhan M, Wang R, Lind ML, Forzani E, Gades NM, Thomas LF, Fryer JD. Commonly disrupted pathways in brain and kidney in a pig model of systemic endotoxemia. J Neuroinflammation 2024; 21:9. [PMID: 38178237 PMCID: PMC10765757 DOI: 10.1186/s12974-023-03002-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 12/19/2023] [Indexed: 01/06/2024] Open
Abstract
Sepsis is a life-threatening state that arises due to a hyperactive inflammatory response stimulated by infection and rarely other insults (e.g., non-infections tissue injury). Although changes in several proinflammatory cytokines and signals are documented in humans and small animal models, far less is known about responses within affected tissues of large animal models. We sought to understand the changes that occur during the initial stages of inflammation by administering intravenous lipopolysaccharide (LPS) to Yorkshire pigs and assessing transcriptomic alterations in the brain, kidney, and whole blood. Robust transcriptional alterations were found in the brain, with upregulated responses enriched in inflammatory pathways and downregulated responses enriched in tight junction and blood vessel functions. Comparison of the inflammatory response in the pig brain to a similar mouse model demonstrated some overlapping changes but also numerous differences, including oppositely dysregulated genes between species. Substantial changes also occurred in the kidneys following LPS with several enriched upregulated pathways (cytokines, lipids, unfolded protein response, etc.) and downregulated gene sets (tube morphogenesis, glomerulus development, GTPase signal transduction, etc.). We also found significant dysregulation of genes in whole blood that fell into several gene ontology categories (cytokines, cell cycle, neutrophil degranulation, etc.). We observed a strong correlation between the brain and kidney responses, with significantly shared upregulated pathways (cytokine signaling, cell death, VEGFA pathways) and downregulated pathways (vasculature and RAC1 GTPases). In summary, we have identified a core set of shared genes and pathways in a pig model of systemic inflammation.
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Affiliation(s)
- Kimberly C Olney
- Department of Neuroscience, Mayo Clinic, 13400 East Shea Boulevard, Scottsdale, AZ, USA
| | - Camila de Ávila
- Department of Neuroscience, Mayo Clinic, 13400 East Shea Boulevard, Scottsdale, AZ, USA
| | - Kennedi T Todd
- Department of Neuroscience, Mayo Clinic, 13400 East Shea Boulevard, Scottsdale, AZ, USA
| | - Lauren E Tallant
- Department of Neuroscience, Mayo Clinic, 13400 East Shea Boulevard, Scottsdale, AZ, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Scottsdale, AZ, USA
| | - J Hudson Barnett
- Department of Neuroscience, Mayo Clinic, 13400 East Shea Boulevard, Scottsdale, AZ, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Scottsdale, AZ, USA
- MD/PhD Training Program, Mayo Clinic, Scottsdale, AZ, USA
| | - Katelin A Gibson
- Department of Neuroscience, Mayo Clinic, 13400 East Shea Boulevard, Scottsdale, AZ, USA
| | - Piyush Hota
- Division of Nephrology & Hypertension, Mayo Clinic, 13400 East Shea Boulevard, Scottsdale, AZ, USA
| | | | - Pinar Cay Durgun
- School of Engineering of Matter, Transport & Energy, Arizona State University, Tempe, AZ, USA
| | - Michael Serhan
- School of Engineering of Matter, Transport & Energy, Arizona State University, Tempe, AZ, USA
| | - Ran Wang
- School of Engineering of Matter, Transport & Energy, Arizona State University, Tempe, AZ, USA
| | - Mary Laura Lind
- School of Engineering of Matter, Transport & Energy, Arizona State University, Tempe, AZ, USA
| | - Erica Forzani
- School of Engineering of Matter, Transport & Energy, Arizona State University, Tempe, AZ, USA
| | - Naomi M Gades
- Department of Comparative Medicine, Mayo Clinic, Scottsdale, AZ, USA
| | - Leslie F Thomas
- Division of Nephrology & Hypertension, Mayo Clinic, 13400 East Shea Boulevard, Scottsdale, AZ, USA.
| | - John D Fryer
- Department of Neuroscience, Mayo Clinic, 13400 East Shea Boulevard, Scottsdale, AZ, USA.
- Mayo Clinic Graduate School of Biomedical Sciences, Scottsdale, AZ, USA.
- MD/PhD Training Program, Mayo Clinic, Scottsdale, AZ, USA.
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Kirchenwitz M, Halfen J, von Peinen K, Prettin S, Kollasser J, Zur Lage S, Blankenfeldt W, Brakebusch C, Rottner K, Steffen A, Stradal TEB. RhoB promotes Salmonella survival by regulating autophagy. Eur J Cell Biol 2023; 102:151358. [PMID: 37703749 DOI: 10.1016/j.ejcb.2023.151358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 07/05/2023] [Accepted: 08/29/2023] [Indexed: 09/15/2023] Open
Abstract
Salmonella enterica serovar Typhimurium manipulates cellular Rho GTPases for host cell invasion by effector protein translocation via the Type III Secretion System (T3SS). The two Guanine nucleotide exchange (GEF) mimicking factors SopE and -E2 and the inositol phosphate phosphatase (PiPase) SopB activate the Rho GTPases Rac1, Cdc42 and RhoA, thereby mediating bacterial invasion. S. Typhimurium lacking these three effector proteins are largely invasion-defective. Type III secretion is crucial for both early and later phases of the intracellular life of S. Typhimurium. Here we investigated whether and how the small GTPase RhoB, known to localize on endomembrane vesicles and at the invasion site of S. Typhimurium, contributes to bacterial invasion and to subsequent steps relevant for S. Typhimurium lifestyle. We show that RhoB is significantly upregulated within hours of Salmonella infection. This effect depends on the presence of the bacterial effector SopB, but does not require its phosphatase activity. Our data reveal that SopB and RhoB bind to each other, and that RhoB localizes on early phagosomes of intracellular S. Typhimurium. Whereas both SopB and RhoB promote intracellular survival of Salmonella, RhoB is specifically required for Salmonella-induced upregulation of autophagy. Finally, in the absence of RhoB, vacuolar escape and cytosolic hyper-replication of S. Typhimurium is diminished. Our findings thus uncover a role for RhoB in Salmonella-induced autophagy, which supports intracellular survival of the bacterium and is promoted through a positive feedback loop by the Salmonella effector SopB.
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Affiliation(s)
- Marco Kirchenwitz
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Jessica Halfen
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Kristin von Peinen
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Silvia Prettin
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Jana Kollasser
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Susanne Zur Lage
- Department Structure and Function of Proteins, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Wulf Blankenfeldt
- Department Structure and Function of Proteins, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Cord Brakebusch
- Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
| | - Klemens Rottner
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany; Division of Molecular Cell Biology, Zoological Institute, Technische Universität Braunschweig, Spielmannstrasse 7, 38106 Braunschweig, Germany
| | - Anika Steffen
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Theresia E B Stradal
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany.
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Pai YC, Li YH, Turner JR, Yu LCH. Transepithelial Barrier Dysfunction Drives Microbiota Dysbiosis to Initiate Epithelial Clock-driven Inflammation. J Crohns Colitis 2023; 17:1471-1488. [PMID: 37004200 PMCID: PMC10588795 DOI: 10.1093/ecco-jcc/jjad064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Indexed: 04/03/2023]
Abstract
BACKGROUND Factors that contribute to inflammatory bowel disease [IBD] pathogenesis include genetic polymorphisms, barrier loss, and microbial dysbiosis. A major knowledge gap exists in the origins of the colitogenic microbiome and its relationship with barrier impairment. Epithelial myosin light chain kinase [MLCK] is a critical regulator of the paracellular barrier, but the effects of MLCK activation on the intraepithelial bacteria [IEB] and dysbiosis are incompletely understood. We hypothesise that MLCK-dependent bacterial endocytosis promotes pathobiont conversion and shapes a colitogenic microbiome. METHODS To explore this, transgenic [Tg] mice with barrier loss induced by intestinal epithelium-specific expression of a constitutively active MLCK were compared with wild-type [WT] mice. RESULTS When progeny of homozygous MLCK-Tg mice were separated after weaning by genotype [Tg/Tg, Tg/WT, WT/WT], increased IEB numbers associated with dysbiosis and more severe colitis were present in Tg/Tg and Tg/WT mice, relative to WT/WT mice. Cohousing with MLCK-Tg mice induced dysbiosis, increased IEB abundance, and exacerbated colitis in WT mice. Conversely, MLCK-Tg mice colonised with WT microbiota at birth displayed increased Escherichia abundance and greater colitis severity by 6 weeks of age. Microarray analysis revealed circadian rhythm disruption in WT mice co-housed with MLCK-Tg mice relative to WT mice housed only with WT mice. This circadian disruption required Rac1/STAT3-dependent microbial invasion but not MLCK activity, and resulted in increased proinflammatory cytokines and glucocorticoid downregulation. CONCLUSIONS The data demonstrate that barrier dysfunction induces dysbiosis and expansion of invasive microbes that lead to circadian disruption and mucosal inflammation. These results suggest that barrier-protective or bacterium-targeted precision medicine approaches may be of benefit to IBD patients.
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Affiliation(s)
- Yu-Chen Pai
- Graduate Institute of Physiology, National Taiwan University College of Medicine, Taipei, Taiwan ROC
| | - Yi-Hsuan Li
- Graduate Institute of Physiology, National Taiwan University College of Medicine, Taipei, Taiwan ROC
| | - Jerrold R Turner
- Brigham's Women Hospital, Harvard Medical School, Boston, MA, USA
| | - Linda Chia-Hui Yu
- Graduate Institute of Physiology, National Taiwan University College of Medicine, Taipei, Taiwan ROC
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9
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Li Q, Sun M, Zhou Q, Li Y, Xu J, Fan H. Integrated analysis of multi-omics data reveals T cell exhaustion in sepsis. Front Immunol 2023; 14:1110070. [PMID: 37077915 PMCID: PMC10108839 DOI: 10.3389/fimmu.2023.1110070] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 03/20/2023] [Indexed: 04/05/2023] Open
Abstract
BackgroundSepsis is a heterogeneous disease, therefore the single-gene-based biomarker is not sufficient to fully understand the disease. Higher-level biomarkers need to be explored to identify important pathways related to sepsis and evaluate their clinical significance.MethodsGene Set Enrichment Analysis (GSEA) was used to analyze the sepsis transcriptome to obtain the pathway-level expression. Limma was used to identify differentially expressed pathways. Tumor IMmune Estimation Resource (TIMER) was applied to estimate immune cell abundance. The Spearman correlation coefficient was used to find the relationships between pathways and immune cell abundance. Methylation and single-cell transcriptome data were also employed to identify important pathway genes. Log-rank test was performed to test the prognostic significance of pathways for patient survival probability. DSigDB was used to mine candidate drugs based on pathways. PyMol was used for 3-D structure visualization. LigPlot was used to plot the 2-D pose view for receptor-ligand interaction.ResultsEighty-four KEGG pathways were differentially expressed in sepsis patients compared to healthy controls. Of those, 10 pathways were associated with 28-day survival. Some pathways were significantly correlated with immune cell abundance and five pathways could be used to distinguish between systemic inflammatory response syndrome (SIRS), bacterial sepsis, and viral sepsis with Area Under the Curve (AUC) above 0.80. Seven related drugs were screened using survival-related pathways.ConclusionSepsis-related pathways can be utilized for disease subtyping, diagnosis, prognosis, and drug screening.
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Affiliation(s)
- Qiaoke Li
- Department of Respiratory and Critical Care Medicine, West China Hospital/West China School of Medicine, Sichuan University, Chengdu, China
| | - Mingze Sun
- Department of Intensive Care Unit, Sichuan Provincial Crops Hospital of Chinese People’s Armed Police Force, Leshan, China
| | - Qi Zhou
- Department of Oncology, Jiang’an Hospital of Traditional Chinese Medicine, Yibin, China
| | - Yulong Li
- Department of Intensive Care Unit, Sichuan Provincial Crops Hospital of Chinese People’s Armed Police Force, Leshan, China
| | - Jinmei Xu
- Department of Intensive Care Unit, Sichuan Provincial Crops Hospital of Chinese People’s Armed Police Force, Leshan, China
| | - Hong Fan
- Department of Respiratory and Critical Care Medicine, West China Hospital/West China School of Medicine, Sichuan University, Chengdu, China
- *Correspondence: Hong Fan,
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10
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Hartland EL, Ghosal D, Giogha C. Manipulation of epithelial cell architecture by the bacterial pathogens Listeria and Shigella. Curr Opin Cell Biol 2022; 79:102131. [PMID: 36215855 DOI: 10.1016/j.ceb.2022.102131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 08/22/2022] [Accepted: 09/06/2022] [Indexed: 01/31/2023]
Abstract
Subversion of the host cell cytoskeleton is a virulence attribute common to many bacterial pathogens. On mucosal surfaces, bacteria have evolved distinct ways of interacting with the polarised epithelium and manipulating host cell structure to propagate infection. For example, Shigella and Listeria induce cytoskeletal changes to induce their own uptake into enterocytes in order to replicate within an intracellular environment and then spread from cell-to-cell by harnessing the host actin cytoskeleton. In this review, we highlight some recent studies that advance our understanding of the role of the host cell cytoskeleton in the mechanical and molecular processes of pathogen invasion, cell-to-cell spread and the impact of infection on epithelial intercellular tension and innate mucosal defence.
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Affiliation(s)
- Elizabeth L Hartland
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Victoria, Australia; Department of Molecular and Translational Science, Monash University, Clayton, Victoria, Australia.
| | - Debnath Ghosal
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC, Australia
| | - Cristina Giogha
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Victoria, Australia; Department of Molecular and Translational Science, Monash University, Clayton, Victoria, Australia
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11
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Mangan MSJ, Gorki F, Krause K, Heinz A, Pankow A, Ebert T, Jahn D, Hiller K, Hornung V, Maurer M, Schmidt FI, Gerhard R, Latz E. Transcriptional licensing is required for Pyrin inflammasome activation in human macrophages and bypassed by mutations causing familial Mediterranean fever. PLoS Biol 2022; 20:e3001351. [PMID: 36342970 PMCID: PMC9671422 DOI: 10.1371/journal.pbio.3001351] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 11/17/2022] [Accepted: 09/23/2022] [Indexed: 11/09/2022] Open
Abstract
Pyrin is a cytosolic immune sensor that nucleates an inflammasome in response to inhibition of RhoA by bacterial virulence factors, triggering the release of inflammatory cytokines, including IL-1β. Gain-of-function mutations in the MEFV gene encoding Pyrin cause autoinflammatory disorders, such as familial Mediterranean fever (FMF) and Pyrin-associated autoinflammation with neutrophilic dermatosis (PAAND). To precisely define the role of Pyrin in pathogen detection in human immune cells, we compared initiation and regulation of the Pyrin inflammasome response in monocyte-derived macrophages (hMDM). Unlike human monocytes and murine macrophages, we determined that hMDM failed to activate Pyrin in response to known Pyrin activators Clostridioides difficile (C. difficile) toxins A or B (TcdA or TcdB), as well as the bile acid analogue BAA-473. The Pyrin inflammasome response was enabled in hMDM by prolonged priming with either LPS or type I or II interferons and required an increase in Pyrin expression. Notably, FMF mutations lifted the requirement for prolonged priming for Pyrin activation in hMDM, enabling Pyrin activation in the absence of additional inflammatory signals. Unexpectedly, in the absence of a Pyrin response, we found that TcdB activated the NLRP3 inflammasome in hMDM. These data demonstrate that regulation of Pyrin activation in hMDM diverges from monocytes and highlights its dysregulation in FMF.
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Affiliation(s)
- Matthew S. J. Mangan
- Institute of Innate Immunity, University Hospital Bonn, University of Bonn, Bonn, Germany
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Friederike Gorki
- Institute of Innate Immunity, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Karoline Krause
- Institute of Allergology, Charité–Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Allergology and Immunology, Berlin, Germany
| | - Alexander Heinz
- Department of Bioinformatics and Biochemistry, Braunschweig Integrated Center of Systems Biology (BRICS), Technische Universität Braunschweig, Braunschweig, Germany
| | - Anne Pankow
- Medizinische Klinik mit Schwerpunkt Rheumatologie und Klinische Immunologie AG Digitale Medizin in der Rheumatologie/ Rheumatologie 4.0 Charité—Universitätsmedizin Berlin (CCM), Berlin, Germany
| | - Thomas Ebert
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Dieter Jahn
- Institute for Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
- Braunschweig Integrated Center of Systems Biology (BRICS), Technische Universität Braunschweig, Braunschweig, Germany
| | - Karsten Hiller
- Department of Bioinformatics and Biochemistry, Braunschweig Integrated Center of Systems Biology (BRICS), Technische Universität Braunschweig, Braunschweig, Germany
- Computational Biology of Infection Research, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Veit Hornung
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Marcus Maurer
- Institute of Allergology, Charité–Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Allergology and Immunology, Berlin, Germany
| | - Florian I. Schmidt
- Institute of Innate Immunity, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Eicke Latz
- Institute of Innate Immunity, University Hospital Bonn, University of Bonn, Bonn, Germany
- German Center for Neurodegenerative Diseases, Bonn, Germany
- Department of Infectious Diseases & Immunology, UMass Medical School, Worcester, Massachusetts, United States of America
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway
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12
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Alqassim SS. Functional Mimicry of Eukaryotic Actin Assembly by Pathogen Effector Proteins. Int J Mol Sci 2022; 23:ijms231911606. [PMID: 36232907 PMCID: PMC9569871 DOI: 10.3390/ijms231911606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/21/2022] [Accepted: 09/22/2022] [Indexed: 11/16/2022] Open
Abstract
The actin cytoskeleton lies at the heart of many essential cellular processes. There are hundreds of proteins that cells use to control the size and shape of actin cytoskeletal networks. As such, various pathogens utilize different strategies to hijack the infected eukaryotic host actin dynamics for their benefit. These include the control of upstream signaling pathways that lead to actin assembly, control of eukaryotic actin assembly factors, encoding toxins that distort regular actin dynamics, or by encoding effectors that directly interact with and assemble actin filaments. The latter class of effectors is unique in that, quite often, they assemble actin in a straightforward manner using novel sequences, folds, and molecular mechanisms. The study of these mechanisms promises to provide major insights into the fundamental determinants of actin assembly, as well as a deeper understanding of host-pathogen interactions in general, and contribute to therapeutic development efforts targeting their respective pathogens. This review discusses mechanisms and highlights shared and unique features of actin assembly by pathogen effectors that directly bind and assemble actin, focusing on eukaryotic actin nucleator functional mimics Rickettsia Sca2 (formin mimic), Burkholderia BimA (Ena/VASP mimic), and Vibrio VopL (tandem WH2-motif mimic).
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Affiliation(s)
- Saif S Alqassim
- College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Building 14, Dubai Health Care City, Dubai P.O. Box 505055, United Arab Emirates
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13
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Rayees S, Joshi JC, Joshi B, Vellingiri V, Banerjee S, Mehta D. Protease-activated receptor 2 promotes clearance of Pseudomonas aeruginosa infection by inducing cAMP-Rac1 signaling in alveolar macrophages. Front Pharmacol 2022; 13:874197. [PMID: 36204227 PMCID: PMC9530345 DOI: 10.3389/fphar.2022.874197] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 08/22/2022] [Indexed: 11/25/2022] Open
Abstract
Efficient phagocytosis of pathogens by the innate immune system during infectious injury is vital for restoring tissue integrity. Impaired phagocytosis, such as in the case of infection with Pseudomonas aeruginosa, a broad-spectrum antibiotic-resistant Gram-negative bacterium, can lead to a life threatening lung disorder, acute lung injury (ALI). Evidence indicates that loss of protease-activated receptor 2 (PAR2) impaired Pseudomonas aeruginosa clearance leading to non-resolvable ALI, but the mechanism remains unclear. Here, we focused on the alveolar macrophages (AMs), the predominant population of lung-resident macrophages involved in sensing bacteria, to understand their role in PAR2-mediated phagocytosis of Pseudomonas aeruginosa. We found that upon binding Pseudomonas aeruginosa, PAR2-expressing but not PAR2-null AMs had increased cAMP levels, which activated Rac1 through protein kinase A. Activated Rac1 increased actin-rich protrusions to augment the phagocytosis of Pseudomonas aeruginosa. Administration of liposomes containing constitutively active Rac1 into PAR2-null mice lungs rescued phagocytosis and enhanced the survival of PAR2-null mice from pneumonia. These studies showed that PAR2 drives the cAMP-Rac1 signaling cascade that activates Pseudomonas aeruginosa phagocytosis in AMs, thereby preventing death from bacterial pneumonia.
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14
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Simvastatin Inhibits Brucella abortus Invasion into RAW 264.7 Cells through Suppression of the Mevalonate Pathway and Promotes Host Immunity during Infection in a Mouse Model. Int J Mol Sci 2022; 23:ijms23158337. [PMID: 35955474 PMCID: PMC9368445 DOI: 10.3390/ijms23158337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/20/2022] [Accepted: 07/27/2022] [Indexed: 11/16/2022] Open
Abstract
Simvastatin is an inhibitor of 3-hydroxy-3-methylglutaryl CoA reductase and has been found to have protective effects against several bacterial infections. In this study, we investigate the effects of simvastatin treatment on RAW 264.7 macrophage cells and ICR mice against Brucella (B.) abortus infections. The invasion assay revealed that simvastatin inhibited the Brucella invasion into macrophage cells by blocking the mevalonic pathway. The treatment of simvastatin enhanced the trafficking of Toll-like receptor 4 in membrane lipid raft microdomains, accompanied by the increased phosphorylation of its downstream signaling pathways, including JAK2 and MAPKs, upon =Brucella infection. Notably, the suppressive effect of simvastatin treatment on Brucella invasion was not dependent on the reduction of cholesterol synthesis but probably on the decline of farnesyl pyrophosphate and geranylgeranyl pyrophosphate synthesis. In addition to a direct brucellacidal ability, simvastatin administration showed increased cytokine TNF-α and differentiation of CD8+ T cells, accompanied by reduced bacterial survival in spleens of ICR mice. These data suggested the involvement of the mevalonate pathway in the phagocytosis of B. abortus into RAW 264.7 macrophage cells and the regulation of simvastatin on the host immune system against Brucella infections. Therefore, simvastatin is a potential candidate for studying alternative therapy against animal brucellosis.
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15
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Role of Host Small GTPases in Apicomplexan Parasite Infection. Microorganisms 2022; 10:microorganisms10071370. [PMID: 35889089 PMCID: PMC9319929 DOI: 10.3390/microorganisms10071370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 12/04/2022] Open
Abstract
The Apicomplexa are obligate intracellular parasites responsible for several important human diseases. These protozoan organisms have evolved several strategies to modify the host cell environment to create a favorable niche for their survival. The host cytoskeleton is widely manipulated during all phases of apicomplexan intracellular infection. Moreover, the localization and organization of host organelles are altered in order to scavenge nutrients from the host. Small GTPases are a class of proteins widely involved in intracellular pathways governing different processes, from cytoskeletal and organelle organization to gene transcription and intracellular trafficking. These proteins are already known to be involved in infection by several intracellular pathogens, including viruses, bacteria and protozoan parasites. In this review, we recapitulate the mechanisms by which apicomplexan parasites manipulate the host cell during infection, focusing on the role of host small GTPases. We also discuss the possibility of considering small GTPases as potential targets for the development of novel host-targeted therapies against apicomplexan infections.
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16
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Interactions of Bacterial Toxin CNF1 and Host JAK1/2 Driven by Liquid-Liquid Phase Separation Enhance Macrophage Polarization. mBio 2022; 13:e0114722. [PMID: 35766380 PMCID: PMC9426534 DOI: 10.1128/mbio.01147-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Urinary tract infections (UTIs) are a global public health concern, which is mainly caused by uropathogenic Escherichia coli (UPEC). Cytotoxic necrotizing factor 1 (CNF1) is a key UPEC toxin and regulates multiple host cellular processes through activating the Rho GTPases; however, the effect of CNF1 on macrophage polarization remains unknown. Here, we found that CNF1 promoted M1 macrophage polarization through regulating NF-κB and JAK-STAT1 signaling pathways in kidney at an early stage of acute UTIs. Notably, we identified CNF1 could directly interact with JAK1/2 through its domain without Rho GTPases activation, which induced JAK1/2 phosphorylation, subsequent STAT1 activation and M1 polarization. Moreover, CNF1 exhibited liquid-liquid phase separation (LLPS) to induce a CNF1-JAK1/2 complex, promoting macrophage reprogramming. These findings highlight the LLPS-dependent and Rho GTPase-independent effect of CNF1 as an adaptor on interfering with host cell signals.
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17
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Simonin JL, Luscher A, Losa D, Badaoui M, van Delden C, Köhler T, Chanson M. Surface Hydration Protects Cystic Fibrosis Airways from Infection by Restoring Junctional Networks. Cells 2022; 11:cells11091587. [PMID: 35563895 PMCID: PMC9105190 DOI: 10.3390/cells11091587] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 04/20/2022] [Accepted: 05/06/2022] [Indexed: 02/01/2023] Open
Abstract
Defective hydration of airway surface mucosa is associated with recurrent lung infection in cystic fibrosis (CF), a disease caused by CF transmembrane conductance regulator (CFTR) gene mutations. Whether the composition and/or presence of an airway surface liquid (ASL) is sufficient to prevent infection remains unclear. The susceptibility to infection of polarized wild type and CFTR knockdown (CFTR-KD) airway epithelial cells was determined in the presence or absence of a healthy ASL or physiological saline. CFTR-KD epithelia exhibited strong ASL volume reduction, enhanced susceptibility to infection, and reduced junctional integrity. Interestingly, the presence of an apical physiological saline alleviated disruption of the airway epithelial barrier by stimulating essential junctional protein expression. Thus, rehydrated CFTR-KD cells were protected from infection despite normally intense bacterial growth. This study indicates that an epithelial integrity gatekeeper is modulated by the presence of an apical liquid volume, irrespective of the liquid's composition and of expression of a functional CFTR.
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Affiliation(s)
- Juliette L. Simonin
- Department of Cell Physiology & Metabolism, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland; (J.L.S.); (D.L.); (M.B.)
| | - Alexandre Luscher
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland; (A.L.); (C.v.D.); (T.K.)
| | - Davide Losa
- Department of Cell Physiology & Metabolism, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland; (J.L.S.); (D.L.); (M.B.)
| | - Mehdi Badaoui
- Department of Cell Physiology & Metabolism, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland; (J.L.S.); (D.L.); (M.B.)
| | - Christian van Delden
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland; (A.L.); (C.v.D.); (T.K.)
- Department of Medicine Specialties, Division of Infectious Diseases, Geneva University Hospitals, 1211 Geneva, Switzerland
| | - Thilo Köhler
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland; (A.L.); (C.v.D.); (T.K.)
| | - Marc Chanson
- Department of Cell Physiology & Metabolism, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland; (J.L.S.); (D.L.); (M.B.)
- Correspondence: ; Tel./Fax: +41-22-37-95-206
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18
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Smith KP, Lee W, Tonelli M, Lee Y, Light SH, Cornilescu G, Chakravarthy S. Solution structure and dynamics of the mitochondrial-targeted GTPase-activating protein (GAP) VopE by an integrated NMR/SAXS approach. Protein Sci 2022; 31:e4282. [PMID: 35137487 PMCID: PMC9047041 DOI: 10.1002/pro.4282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 01/17/2022] [Accepted: 01/27/2022] [Indexed: 11/11/2022]
Abstract
The bacterial pathogen Vibrio cholerae use a type III secretion system to inject effector proteins into a host cell. Recently, a putative Toxic GTPase Activating Protein (ToxGAP) called VopE was identified as a T3SS substrate and virulence factor that affected host mitochondrial dynamics and immune response. However, biophysical and structural characterization has been absent. Here, we describe solution NMR structure of the putative GAP domain (73-204) of VopE. Using SEC-SAXS and RDC data, we restrained the MD process to efficiently determine the overall fold and improve the quality of the output calculated structures. Comparing the structure of VopE with other ToxGAP's revealed a similar overall fold with several features unique to VopE. Specifically, the "Bulge 1", α1 helix, and noteworthy "backside linker" elements on the N-terminus are dissimilar to the other ToxGAP's. By using NMR relaxation dispersion experiments, we demonstrate that these regions undergo motions on a >6 s-1 timescale. Based on the disposition of these mobile regions relative to the putative catalytic arginine residue, we hypothesize the protein may undergo structural changes to bind cognate GTPases. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Kyle P Smith
- Current, Xilio Therapeutics, Waltham, MA, USA.,Former, Department of Cell & Developmental Biology, Northwestern University Chicago, IL, USA
| | - Woonghee Lee
- Department of Chemistry, University of Colorado-Denver, Denver, CO, USA
| | - Marco Tonelli
- National Magnetic Resonance Facility at Madison, Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Yeongjoon Lee
- Department of Chemistry, University of Colorado-Denver, Denver, CO, USA
| | - Samuel H Light
- Department of Microbiology, University of Chicago, Chicago, IL, USA
| | - Gabriel Cornilescu
- Advanced Technology Research Facility, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., National Cancer Institute, National Institutes of Health, Frederick, MD, USA
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Carlini F, Maroccia Z, Fiorentini C, Travaglione S, Fabbri A. Effects of the Escherichia coli Bacterial Toxin Cytotoxic Necrotizing Factor 1 on Different Human and Animal Cells: A Systematic Review. Int J Mol Sci 2021; 22:ijms222212610. [PMID: 34830494 PMCID: PMC8621085 DOI: 10.3390/ijms222212610] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/19/2021] [Accepted: 11/20/2021] [Indexed: 12/13/2022] Open
Abstract
Cytotoxic necrotizing factor 1 (CNF1) is a bacterial virulence factor, the target of which is represented by Rho GTPases, small proteins involved in a huge number of crucial cellular processes. CNF1, due to its ability to modulate the activity of Rho GTPases, represents a widely used tool to unravel the role played by these regulatory proteins in different biological processes. In this review, we summarized the data available in the scientific literature concerning the observed in vitro effects induced by CNF1. An article search was performed on electronic bibliographic resources. Screenings were performed of titles, abstracts, and full-texts according to PRISMA guidelines, whereas eligibility criteria were defined for in vitro studies. We identified a total of 299 records by electronic article search and included 76 original peer-reviewed scientific articles reporting morphological or biochemical modifications induced in vitro by soluble CNF1, either recombinant or from pathogenic Escherichia coli extracts highly purified with chromatographic methods. Most of the described CNF1-induced effects on cultured cells are ascribable to the modulating activity of the toxin on Rho GTPases and the consequent effects on actin cytoskeleton organization. All in all, the present review could be a prospectus about the CNF1-induced effects on cultured cells reported so far.
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Affiliation(s)
- Francesca Carlini
- Department of Cardiovascular, Endocrine-Metabolic Diseases and Ageing, Istituto Superiore di Sanità, 00161 Rome, Italy; (F.C.); (Z.M.); (S.T.)
| | - Zaira Maroccia
- Department of Cardiovascular, Endocrine-Metabolic Diseases and Ageing, Istituto Superiore di Sanità, 00161 Rome, Italy; (F.C.); (Z.M.); (S.T.)
| | - Carla Fiorentini
- Associazione Ricerca Terapie Oncologiche Integrate, ARTOI, 00165 Rome, Italy;
| | - Sara Travaglione
- Department of Cardiovascular, Endocrine-Metabolic Diseases and Ageing, Istituto Superiore di Sanità, 00161 Rome, Italy; (F.C.); (Z.M.); (S.T.)
| | - Alessia Fabbri
- Department of Cardiovascular, Endocrine-Metabolic Diseases and Ageing, Istituto Superiore di Sanità, 00161 Rome, Italy; (F.C.); (Z.M.); (S.T.)
- Correspondence: ; Tel.: +39-06-4990-2939
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Aspergillus fumigatus versus Genus Aspergillus: Conservation, Adaptive Evolution and Specific Virulence Genes. Microorganisms 2021; 9:microorganisms9102014. [PMID: 34683335 PMCID: PMC8539515 DOI: 10.3390/microorganisms9102014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 09/18/2021] [Accepted: 09/20/2021] [Indexed: 12/15/2022] Open
Abstract
Aspergillus is an important fungal genus containing economically important species, as well as pathogenic species of animals and plants. Using eighteen fungal species of the genus Aspergillus, we conducted a comprehensive investigation of conserved genes and their evolution. This also allows us to investigate the selection pressure driving the adaptive evolution in the pathogenic species A. fumigatus. Among single-copy orthologs (SCOs) for A. fumigatus and the closely related species A. fischeri, we identified 122 versus 50 positively selected genes (PSGs), respectively. Moreover, twenty conserved genes of unknown function were established to be positively selected and thus important for adaption. A. fumigatus PSGs interacting with human host proteins show over-representation of adaptive, symbiosis-related, immunomodulatory and virulence-related pathways, such as the TGF-β pathway, insulin receptor signaling, IL1 pathway and interfering with phagosomal GTPase signaling. Additionally, among the virulence factor coding genes, secretory and membrane protein-coding genes in multi-copy gene families, 212 genes underwent positive selection and also suggest increased adaptation, such as fungal immune evasion mechanisms (aspf2), siderophore biosynthesis (sidD), fumarylalanine production (sidE), stress tolerance (atfA) and thermotolerance (sodA). These genes presumably contribute to host adaptation strategies. Genes for the biosynthesis of gliotoxin are shared among all the close relatives of A. fumigatus as an ancient defense mechanism. Positive selection plays a crucial role in the adaptive evolution of A. fumigatus. The genome-wide profile of PSGs provides valuable targets for further research on the mechanisms of immune evasion, antimycotic targeting and understanding fundamental virulence processes.
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21
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Post-Translational Modification and Subcellular Compartmentalization: Emerging Concepts on the Regulation and Physiopathological Relevance of RhoGTPases. Cells 2021; 10:cells10081990. [PMID: 34440759 PMCID: PMC8393718 DOI: 10.3390/cells10081990] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/31/2021] [Accepted: 08/02/2021] [Indexed: 12/26/2022] Open
Abstract
Cells and tissues are continuously exposed to both chemical and physical stimuli and dynamically adapt and respond to this variety of external cues to ensure cellular homeostasis, regulated development and tissue-specific differentiation. Alterations of these pathways promote disease progression-a prominent example being cancer. Rho GTPases are key regulators of the remodeling of cytoskeleton and cell membranes and their coordination and integration with different biological processes, including cell polarization and motility, as well as other signaling networks such as growth signaling and proliferation. Apart from the control of GTP-GDP cycling, Rho GTPase activity is spatially and temporally regulated by post-translation modifications (PTMs) and their assembly onto specific protein complexes, which determine their controlled activity at distinct cellular compartments. Although Rho GTPases were traditionally conceived as targeted from the cytosol to the plasma membrane to exert their activity, recent research demonstrates that active pools of different Rho GTPases also localize to endomembranes and the nucleus. In this review, we discuss how PTM-driven modulation of Rho GTPases provides a versatile mechanism for their compartmentalization and functional regulation. Understanding how the subcellular sorting of active small GTPase pools occurs and what its functional significance is could reveal novel therapeutic opportunities.
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22
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Armijos-Jaramillo V, Espinosa N, Vizcaíno K, Santander-Gordón D. A Novel In Silico Method for Molecular Mimicry Detection Finds a Formin with the Potential to Manipulate the Maize Cell Cytoskeleton. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:815-825. [PMID: 33755496 DOI: 10.1094/mpmi-11-20-0332-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Molecular mimicry is one of the evolutionary strategies that parasites use to manipulate the host metabolism and perform an effective infection. This phenomenon has been observed in several animal and plant pathosystems. Despite the relevance of this mechanism in pathogenesis, little is known about it in fungus-plant interactions. For that reason, we performed an in silico method to select plausible mimicry candidates for the Ustilago maydis-maize interaction. Our methodology used a tripartite sequence comparison between the parasite, the host, and nonparasitic organisms' genomes. Furthermore, we used RNA sequencing information to identify gene coexpression, and we determined subcellular localization to detect potential cases of colocalization in the imitator-imitated pairs. With these approximations, we found a putative extracellular formin in U. maydis with the potential to rearrange the host cell cytoskeleton. In parallel, we detected at least two maize genes involved in the cytoskeleton rearrangement differentially expressed under U. maydis infection; thus, this find increases the expectation for the potential mimicry role of the fungal protein. The use of several sources of data led us to develop a strict and replicable in silico methodology to detect molecular mimicry in pathosystems with enough information available. Furthermore, this is the first time that a genomewide search has been performed to detect molecular mimicry in a U. maydis-maize system. Additionally, to allow the reproducibility of this experiment and the use of this pipeline, we created a Web server called Molecular Mimicry Finder.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Vinicio Armijos-Jaramillo
- Carrera de Ingeniería en Biotecnología, Facultad de Ingeniería y Ciencias Aplicadas, Universidad de Las Américas, Quito, Ecuador
- Grupo de Bio-Quimioinformática, Universidad de Las Américas, Quito, Ecuador
| | - Nicole Espinosa
- Carrera de Ingeniería en Biotecnología, Facultad de Ingeniería y Ciencias Aplicadas, Universidad de Las Américas, Quito, Ecuador
| | - Karla Vizcaíno
- Carrera de Ingeniería en Biotecnología, Facultad de Ingeniería y Ciencias Aplicadas, Universidad de Las Américas, Quito, Ecuador
| | - Daniela Santander-Gordón
- Carrera de Ingeniería en Biotecnología, Facultad de Ingeniería y Ciencias Aplicadas, Universidad de Las Américas, Quito, Ecuador
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Abstract
Pathogens have evolved smart strategies to invade hosts and hijack their immune responses. One such strategy is the targeting of the host RhoGTPases by toxins or virulence factors to hijack the cytoskeleton dynamic and immune processes. In response to this microbial attack, the host has evolved an elegant strategy to monitor the function of virulence factors and toxins by sensing the abnormal activity of RhoGTPases. This innate immune strategy of sensing bacterial effector targeting RhoGTPase appears to be a bona fide example of effector-triggered immunity (ETI). Here, we review recently discovered mechanisms by which the host can sense the activity of these toxins through NOD and NOD-like receptors (NLRs).
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Affiliation(s)
| | - Laurent Boyer
- Université Côte d’Azur, Inserm, C3M, Nice, France
- * E-mail:
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Bonavita R, Laukkanen MO. Common Signal Transduction Molecules Activated by Bacterial Entry into a Host Cell and by Reactive Oxygen Species. Antioxid Redox Signal 2021; 34:486-503. [PMID: 32600071 DOI: 10.1089/ars.2019.7968] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Significance: An increasing number of pathogens are acquiring resistance to antibiotics. Efficient antimicrobial drug regimens are important even for the most advanced therapies, which range from cutting-edge invasive clinical protocols, such as robotic surgeries, to the treatment of harmless bacterial diseases and to minor scratches to the skin. Therefore, there is an urgent need to survey alternative antimicrobial drugs that can reinforce or replace existing antibiotics. Recent Advances: Bacterial proteins that are critical for energy metabolism, promising novel anticancer thiourea derivatives, and the use of synthetic molecules that increase the sensitivity of currently used antibiotics are among the recently discovered antimicrobial drugs. Critical Issues: In the development of new drugs, serious consideration should be given to the previous bacterial evolutionary selection caused by antibiotics, by the high proliferation rate of bacteria, and by the simple prokaryotic structure of bacteria. Future Directions: The survey of drug targets has mainly focused on bacterial proteins, although host signaling molecules involved in the treatment of various pathologies may have unknown antimicrobial characteristics. Recent data have suggested that small molecule inhibitors might enhance the effect of antibiotics, for example, by limiting bacterial entry into host cells. Phagocytosis, the mechanism by which host cells internalize pathogens through β-actin cytoskeletal rearrangement, induces calcium signaling, small GTPase activation, and phosphorylation of the phosphatidylinositol 3-kinase-serine/threonine-specific protein kinase B pathway. Antioxid. Redox Signal. 34, 486-503.
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Affiliation(s)
- Raffaella Bonavita
- Experimental Institute of Endocrinology and Oncology G. Salvatore, IEOS CNR, Naples, Italy
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25
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Non-alcoholic fatty liver disease: a metabolic burden promoting atherosclerosis. Clin Sci (Lond) 2021; 134:1775-1799. [PMID: 32677680 DOI: 10.1042/cs20200446] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 06/06/2020] [Accepted: 06/29/2020] [Indexed: 02/07/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD) has become the fastest growing chronic liver disease, with a prevalence of up to 25% worldwide. Individuals with NAFLD have a high risk of disease progression to cirrhosis, hepatocellular carcinoma (HCC), and liver failure. With the exception of intrahepatic burden, cardiovascular disease (CVD) and especially atherosclerosis (AS) are common complications of NAFLD. Furthermore, CVD is a major cause of death in NAFLD patients. Additionally, AS is a metabolic disorder highly associated with NAFLD, and individual NAFLD pathologies can greatly increase the risk of AS. It is increasingly clear that AS-associated endothelial cell damage, inflammatory cell activation, and smooth muscle cell proliferation are extensively impacted by NAFLD-induced systematic dyslipidemia, inflammation, oxidative stress, the production of hepatokines, and coagulations. In clinical trials, drug candidates for NAFLD management have displayed promising effects for the treatment of AS. In this review, we summarize the key molecular events and cellular factors contributing to the metabolic burden induced by NAFLD on AS, and discuss therapeutic strategies for the improvement of AS in individuals with NAFLD.
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26
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Wang C, Zhang H, Fu J, Wang M, Cai Y, Ding T, Jiang J, Koehler JE, Liu X, Yuan C. Bartonella type IV secretion effector BepC induces stress fiber formation through activation of GEF-H1. PLoS Pathog 2021; 17:e1009065. [PMID: 33508039 PMCID: PMC7842913 DOI: 10.1371/journal.ppat.1009065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 10/13/2020] [Indexed: 12/27/2022] Open
Abstract
Bartonella T4SS effector BepC was reported to mediate internalization of big Bartonella aggregates into host cells by modulating F-actin polymerization. After that, BepC was indicated to induce host cell fragmentation, an interesting cell phenotype that is characterized by failure of rear-end retraction during cell migration, and subsequent dragging and fragmentation of cells. Here, we found that expression of BepC resulted in significant stress fiber formation and contractile cell morphology, which depended on combination of the N-terminus FIC (filamentation induced by c-AMP) domain and C-terminus BID (Bartonellaintracellular delivery) domain of BepC. The FIC domain played a key role in BepC-induced stress fiber formation and cell fragmentation because deletion of FIC signature motif or mutation of two conserved amino acid residues abolished BepC-induced cell fragmentation. Immunoprecipitation confirmed the interaction of BepC with GEF-H1 (a microtubule-associated RhoA guanosine exchange factor), and siRNA-mediated depletion of GEF-H1 prevented BepC-induced stress fiber formation. Interaction with BepC caused the dissociation of GEF-H1 from microtubules and activation of RhoA to induce formation of stress fibers. The ROCK (Rho-associated protein kinase) inhibitor Y27632 completely blocked BepC effects on stress fiber formation and cell contractility. Moreover, stress fiber formation by BepC increased the stability of focal adhesions, which consequently impeded rear-edge detachment. Overall, our study revealed that BepC-induced stress fiber formation was achieved through the GEF-H1/RhoA/ROCK pathway. Intracellular pathogens modulate host cell actin cytoskeleton by secreting an array of effector molecules to ensure their cell invasion and intracellular survival. The zoonotic pathogen Bartonella spp trigger massive F-actin polymerization of host cells resulting the internalization of large bacterial aggregates (called “invasome” structure), which is dependent on a functional VirB/VirD4 type IV secretion system (T4SS) and its translocated Bep effector proteins. Here, we have used cell infection and ectopic expression assay to identify that Bartonella T4SS effector BepC induces stress fiber formation in infected host cells. However, BepC also disrupts the balance of stress fiber formation and focal adhesion maturation, and eventually causes cell fragmentation. Using immunoprecipitation and RNAi approaches, we identify GEF-H1 is the host factor targeted by BepC. Interaction with BepC induces the release of GEF-H1 from microtubules to plasma membrane and subsequently activates RhoA-ROCK to induce stress fiber formation. These findings shed light on our understanding of how Bartonella invade host cell and establish infection.
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Affiliation(s)
- Chunyan Wang
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai, China
| | - Haoran Zhang
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai, China
| | - Jiaqi Fu
- Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Meng Wang
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai, China
| | - Yuhao Cai
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai, China
| | - Tianyun Ding
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai, China
| | - Jiezhang Jiang
- Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Jane E. Koehler
- Department of Medicine, Division of Infectious Diseases, and the Microbial Pathogenesis and Host Defense Program, University of California, San Francisco, California, United States of America
| | - Xiaoyun Liu
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
- * E-mail: (XL); (CY)
| | - Congli Yuan
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai, China
- * E-mail: (XL); (CY)
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Lim C, Berk JM, Blaise A, Bircher J, Koleske AJ, Hochstrasser M, Xiong Y. Crystal structure of a guanine nucleotide exchange factor encoded by the scrub typhus pathogen Orientia tsutsugamushi. Proc Natl Acad Sci U S A 2020; 117:30380-30390. [PMID: 33184172 PMCID: PMC7720168 DOI: 10.1073/pnas.2018163117] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Rho family GTPases regulate an array of cellular processes and are often modulated by pathogens to promote infection. Here, we identify a cryptic guanine nucleotide exchange factor (GEF) domain in the OtDUB protein encoded by the pathogenic bacterium Orientia tsutsugamushi A proteomics-based OtDUB interaction screen identified numerous potential host interactors, including the Rho GTPases Rac1 and Cdc42. We discovered a domain in OtDUB with Rac1/Cdc42 GEF activity (OtDUBGEF), with higher activity toward Rac1 in vitro. While this GEF bears no obvious sequence similarity to known GEFs, crystal structures of OtDUBGEF alone (3.0 Å) and complexed with Rac1 (1.7 Å) reveal striking convergent evolution, with a unique topology, on a V-shaped bacterial GEF fold shared with other bacterial GEF domains. Structure-guided mutational analyses identified residues critical for activity and a mechanism for nucleotide displacement. Ectopic expression of OtDUB activates Rac1 preferentially in cells, and expression of the OtDUBGEF alone alters cell morphology. Cumulatively, this work reveals a bacterial GEF within the multifunctional OtDUB that co-opts host Rac1 signaling to induce changes in cytoskeletal structure.
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Affiliation(s)
- Christopher Lim
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520
| | - Jason M Berk
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520
| | - Alyssa Blaise
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520
| | - Josie Bircher
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520
| | - Anthony J Koleske
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520
| | - Mark Hochstrasser
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520
| | - Yong Xiong
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520
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28
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Weil T, Ometto L, Esteve-Codina A, Gómez-Garrido J, Oppedisano T, Lotti C, Dabad M, Alioto T, Vrhovsek U, Hogenhout S, Anfora G. Linking omics and ecology to dissect interactions between the apple proliferation phytoplasma and its psyllid vector Cacopsylla melanoneura. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 127:103474. [PMID: 33007407 DOI: 10.1016/j.ibmb.2020.103474] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 09/08/2020] [Accepted: 09/17/2020] [Indexed: 06/11/2023]
Abstract
Phytoplasmas are bacterial plant pathogens that are detrimental to many plants and cause devastating effects on crops. They are not viable outside their host plants and depend on specific insect vectors for their transmission. So far, research has largely focused on plant-pathogen interactions, while the complex interactions between phytoplasmas and insect vectors are far less understood. Here, we used next-generation sequencing to investigate how transcriptional profiles of the vector psyllid Cacopsylla melanoneura (Hemiptera, Psyllidae) are altered during infection by the bacterium Candidatus Phytoplasma mali (P. mali), which causes the economically important apple proliferation disease. This first de novo transcriptome assembly of an apple proliferation vector revealed that mainly genes involved in small GTPase mediated signal transduction, nervous system development, adhesion, reproduction, actin-filament based and rhythmic processes are significantly altered upon P. mali infection. Furthermore, the presence of P. mali is accompanied by significant changes in carbohydrate and polyol levels, as revealed by metabolomics analysis. Taken together, our results suggest that infection with P. mali impacts on the insect vector physiology, which in turn likely affects the ability of the vector to transmit phytoplasma.
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Affiliation(s)
- Tobias Weil
- Research and Innovation Center, Fondazione E. Mach, 38010, San Michele all'Adige (TN), Italy.
| | - Lino Ometto
- Research and Innovation Center, Fondazione E. Mach, 38010, San Michele all'Adige (TN), Italy; Department of Biology and Biotechnology, University of Pavia, 27100, Pavia, Italy
| | - Anna Esteve-Codina
- CNAG-CRG, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, 08028, Barcelona, Spain
| | - Jèssica Gómez-Garrido
- CNAG-CRG, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, 08028, Barcelona, Spain
| | - Tiziana Oppedisano
- Research and Innovation Center, Fondazione E. Mach, 38010, San Michele all'Adige (TN), Italy; Present address: Hermiston Agricultural Research and Extension Center, Oregon State University, Hermiston (OR, USA
| | - Cesare Lotti
- Research and Innovation Center, Fondazione E. Mach, 38010, San Michele all'Adige (TN), Italy
| | - Marc Dabad
- CNAG-CRG, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, 08028, Barcelona, Spain
| | - Tyler Alioto
- CNAG-CRG, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, 08028, Barcelona, Spain; Universitat Pompeu Fabra (UPF), 08003, Barcelona, Spain
| | - Urska Vrhovsek
- Research and Innovation Center, Fondazione E. Mach, 38010, San Michele all'Adige (TN), Italy
| | - Saskia Hogenhout
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Gianfranco Anfora
- Research and Innovation Center, Fondazione E. Mach, 38010, San Michele all'Adige (TN), Italy; Centre Agriculture Food Environment, University of Trento, 38010, San Michele all'Adige (TN), Italy
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29
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Nomura R, Otsugu M, Hamada M, Matayoshi S, Teramoto N, Iwashita N, Naka S, Matsumoto-Nakano M, Nakano K. Potential involvement of Streptococcus mutans possessing collagen binding protein Cnm in infective endocarditis. Sci Rep 2020; 10:19118. [PMID: 33154489 PMCID: PMC7645802 DOI: 10.1038/s41598-020-75933-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 10/22/2020] [Indexed: 12/15/2022] Open
Abstract
Streptococcus mutans, a significant contributor to dental caries, is occasionally isolated from the blood of patients with infective endocarditis. We previously showed that S. mutans strains expressing collagen-binding protein (Cnm) are present in the oral cavity of approximately 10-20% of humans and that they can effectively invade human umbilical vein endothelial cells (HUVECs). Here, we investigated the potential molecular mechanisms of HUVEC invasion by Cnm-positive S. mutans. The ability of Cnm-positive S. mutans to invade HUVECs was significantly increased by the presence of serum, purified type IV collagen, and fibrinogen (p < 0.001). Microarray analyses of HUVECs infected by Cnm-positive or -negative S. mutans strains identified several transcripts that were differentially upregulated during invasion, including those encoding the small G protein regulatory proteins ARHGEF38 and ARHGAP9. Upregulation of these proteins occurred during invasion only in the presence of serum. Knockdown of ARHGEF38 strongly reduced HUVEC invasion by Cnm-positive S. mutans. In a rat model of infective endocarditis, cardiac endothelial cell damage was more prominent following infection with a Cnm-positive strain compared with a Cnm-negative strain. These results suggest that the type IV collagen-Cnm-ARHGEF38 pathway may play a crucial role in the pathogenesis of infective endocarditis.
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Affiliation(s)
- Ryota Nomura
- Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, 1-8 Yamada-oka, Suita, Osaka, 565-0871, Japan.
| | - Masatoshi Otsugu
- Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, 1-8 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Masakazu Hamada
- Department of Oral and Maxillofacial Surgery II, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Saaya Matayoshi
- Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, 1-8 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | | | - Naoki Iwashita
- Department of Pharmacology, School of Veterinary Medicine, Azabu University, Sagamihara, Kanagawa, Japan
| | - Shuhei Naka
- Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Michiyo Matsumoto-Nakano
- Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Kazuhiko Nakano
- Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, 1-8 Yamada-oka, Suita, Osaka, 565-0871, Japan
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Giorgi Silveira R, Perelló Ferrúa C, do Amaral CC, Fernandez Garcia T, de Souza KB, Nedel F. MicroRNAs expressed in neuronal differentiation and their associated pathways: Systematic review and bioinformatics analysis. Brain Res Bull 2020; 157:140-148. [PMID: 31945407 DOI: 10.1016/j.brainresbull.2020.01.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 12/30/2019] [Accepted: 01/09/2020] [Indexed: 12/15/2022]
Abstract
MicroRNAs (miRNAs) plays an important role in the human brain from the embryonic period to adulthood. In this sense, they influence the development of neural stem cells (NSCs), regulating cellular differentiation and survival. Therefore, due to the importance of better comprehending the regulation of miRNAs in NSCs differentiation and the lack of studies that show the panorama of miRNAs and their signaling pathways studied until now we aimed to systematically review the literature to identify which miRNAs are currently being associated with neuronal differentiation and using bioinformatics analysis to identify their related pathways. A search was carried out in the following databases: Scientific Electronic Library Online (Scielo), National Library of Medicine National Institutes of Health (PubMed), Scopus, Web of Science and Science Direct, using the descriptors "(microRNA [MeSH])" and "(neurogenesis [MeSH])". From the articles found, two independent and previously calibrated reviewers, using the EndNote X7 (Thomson Reuters, New York, NY, US), selected those that concern miRNA in the development of NSCs, based on in vitro studies. After, bioinformatic analysis was performed using the software DIANA Tools, mirPath v.3. Subsequently, data was tabulated, analyzed and interpreted. Among the 106 miRNAs cited by included studies, 55 were up-regulated and 47 were down-regulated. The bioinformatics analysis revealed that among the up-regulated miRNAs there were 24 total and 6 union pathways, and 3 presented a statistically significant difference (p ≤ 0.05). Among the down-regulated miRNAs, 46 total and 13 union pathways were found, with 7 presenting a significant difference (p ≤ 0.05). The miR-125a-5p, miR-423-5p, miR-320 were the most frequently found miRNAs in the pathways determined by bioinformatics. In this study a panel of altered miRNAs in neuronal differentiation was created with their related pathways, which could be a step towards understanding the complex network of miRNAs in neuronal differentiation.
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Affiliation(s)
- Roberta Giorgi Silveira
- Graduate Program in Health and Behavior, Catholic University of Pelotas, Pelotas, RS, 96010-901, Brazil
| | - Camila Perelló Ferrúa
- Graduate Program in Health and Behavior, Catholic University of Pelotas, Pelotas, RS, 96010-901, Brazil
| | - Cainá Corrêa do Amaral
- Graduate Program in Health and Behavior, Catholic University of Pelotas, Pelotas, RS, 96010-901, Brazil
| | - Tiago Fernandez Garcia
- Graduate Program in Health and Behavior, Catholic University of Pelotas, Pelotas, RS, 96010-901, Brazil
| | - Karoline Brizola de Souza
- Graduate Program in Health and Behavior, Catholic University of Pelotas, Pelotas, RS, 96010-901, Brazil
| | - Fernanda Nedel
- Graduate Program in Health and Behavior, Catholic University of Pelotas, Pelotas, RS, 96010-901, Brazil.
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31
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Margalit A, Kavanagh K, Carolan JC. Characterization of the Proteomic Response of A549 Cells Following Sequential Exposure to Aspergillus fumigatus and Pseudomonas aeruginosa. J Proteome Res 2020; 19:279-291. [PMID: 31693381 DOI: 10.1021/acs.jproteome.9b00520] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Aspergillus fumigatus and Pseudomonas aeruginosa are the most prevalent fungal and bacterial pathogens associated with cystic-fibrosis-related infections, respectively. P. aeruginosa eventually predominates as the primary pathogen, though it is unknown why this is the case. Label-free quantitative proteomics was employed to investigate the cellular response of the alveolar epithelial cell line, A549, to coexposure of A. fumigatus and P. aeruginosa. These studies revealed a significant increase in the rate of P. aeruginosa proliferation where A. fumigatus was present. Shotgun proteomics performed on A549 cells exposed to either A. fumigatus or P. aeruginosa or to A. fumigatus and P. aeruginosa sequentially revealed distinct changes to the host cell proteome in response to either or both pathogens. While key signatures of infection were retained among all pathogen-exposed groups, including changes in mitochondrial activity and energy output, the relative abundance of proteins associated with endocytosis, phagosomes, and lysosomes was decreased in sequentially exposed cells compared to cells exposed to either pathogen. Our findings indicate that A. fumigatus renders A549 cells unable to internalize bacteria, thus providing an environment in which P. aeruginosa can proliferate. This research provides novel insights into the whole-cell proteomic response of A549 cells to A. fumigatus and P. aeruginosa and highlights distinct differences in the proteome following sequential exposure to both pathogens, which may explain why P. aeruginosa can predominate.
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Affiliation(s)
- Anatte Margalit
- Department of Biology , Maynooth University , Maynooth, Co. Kildare W23F2H6 , Ireland
| | - Kevin Kavanagh
- Department of Biology , Maynooth University , Maynooth, Co. Kildare W23F2H6 , Ireland
| | - James C Carolan
- Department of Biology , Maynooth University , Maynooth, Co. Kildare W23F2H6 , Ireland
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32
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Caven L, Carabeo RA. Pathogenic Puppetry: Manipulation of the Host Actin Cytoskeleton by Chlamydia trachomatis. Int J Mol Sci 2019; 21:ijms21010090. [PMID: 31877733 PMCID: PMC6981773 DOI: 10.3390/ijms21010090] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 12/18/2019] [Accepted: 12/19/2019] [Indexed: 12/25/2022] Open
Abstract
The actin cytoskeleton is crucially important to maintenance of the cellular structure, cell motility, and endocytosis. Accordingly, bacterial pathogens often co-opt the actin-restructuring machinery of host cells to access or create a favorable environment for their own replication. The obligate intracellular organism Chlamydia trachomatis and related species exemplify this dynamic: by inducing actin polymerization at the site of pathogen-host attachment, Chlamydiae induce their own uptake by the typically non-phagocytic epithelium they infect. The interaction of chlamydial adhesins with host surface receptors has been implicated in this effect, as has the activity of the chlamydial effector TarP (translocated actin recruitment protein). Following invasion, C. trachomatis dynamically assembles and maintains an actin-rich cage around the pathogen’s membrane-bound replicative niche, known as the chlamydial inclusion. Through further induction of actin polymerization and modulation of the actin-crosslinking protein myosin II, C. trachomatis promotes egress from the host via extrusion of the inclusion. In this review, we present the experimental findings that can inform our understanding of actin-dependent chlamydial pathogenesis, discuss lingering questions, and identify potential avenues of future study.
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Affiliation(s)
- Liam Caven
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164, USA;
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198-5900, USA
| | - Rey A. Carabeo
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198-5900, USA
- Correspondence: ; Tel.: +1-402-836-9778
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33
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Lee WY. "Hairiness" is a Facsimile of Reorganized Cytoskeletons: A Cytopathic Effect of Coxiella burnetii. Yonsei Med J 2019; 60:890-897. [PMID: 31538423 PMCID: PMC6753337 DOI: 10.3349/ymj.2019.60.10.890] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 08/20/2019] [Accepted: 08/21/2019] [Indexed: 01/14/2023] Open
Abstract
In 1993, I reported that Coxiella burnetii transforms human B cells into hairy cells (cbHCs), the first hairy cell reported outside of hairy cell leukemia (HCL). Over last few decades, advances in molecular biology have provided evidence supporting that C. burnetii induces hairiness and inhibits the apoptosis of host cells. The present review summarizes new information in support of cbHC. C. burnetii was shown to induce reorganization of the cytoskeleton and to inhibit apoptosis in host cells. Peritoneal B1a cells were found to be permissive for virulent C. burnetii Nine Mile phase I (NMI) strains in mice. C. burnetii severely impaired E-cad expression in circulating cells of Q fever patients. B-cell non-Hodgkin lymphoma was linked to C. burnetii. Mutation of BRAF V600E was pronounced in HCL, but "hairiness" was not linked to the mutation. Risk factors shared among coxiellosis and HCL in humans and animals were reported in patients with Q-fever. Accordingly, I propose that C. burnetii induces reorganization of the cytoskeleton and inhibits apoptosis as cytopathic effects that are not target cell specific. The observed hairiness in cbHC appears to be a fixed image of dynamic nature, and hairy cells in HCL are distinct among lymphoid cells in circulation. As the cytoskeleton plays key roles in maintaining cell structural integrity in health and disease, the pathophysiology of similar cytopathic effects should be addressed in other diseases, such as myopathies, B-cell dyscrasias, and autoimmune syndromes.
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Affiliation(s)
- Won Young Lee
- Emeritus Professor, Yonsei University College of Medicine, Seoul, Korea.
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34
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Abstract
Transition state theory teaches that chemically stable mimics of enzymatic transition states will bind tightly to their cognate enzymes. Kinetic isotope effects combined with computational quantum chemistry provides enzymatic transition state information with sufficient fidelity to design transition state analogues. Examples are selected from various stages of drug development to demonstrate the application of transition state theory, inhibitor design, physicochemical characterization of transition state analogues, and their progress in drug development.
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Affiliation(s)
- Vern L. Schramm
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
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35
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Zhao Z, Liu J, Deng Y, Huang W, Ren C, Call DR, Hu C. The Vibrio alginolyticus T3SS effectors, Val1686 and Val1680, induce cell rounding, apoptosis and lysis of fish epithelial cells. Virulence 2018; 9:318-330. [PMID: 29252102 PMCID: PMC5955196 DOI: 10.1080/21505594.2017.1414134] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Vibrio alginolyticus is a Gram-negative bacterium that is an opportunistic pathogen of both marine animals and people. Its pathogenesis likely involves type III secretion system (T3SS) mediated induction of rapid apoptosis, cell rounding and osmotic lysis of infected eukaryotic cells. Herein, we report that effector proteins, Val1686 and Val1680 from V. alginolyticus, were responsible for T3SS-mediated death of fish cells. Val1686 is a Fic-domain containing protein that not only contributed to cell rounding by inhibiting Rho guanosine triphosphatases (GTPases), but was requisite for the induction of apoptosis because the deletion mutant (Δval1686) was severely weakened in its ability to induce cell rounding and apoptosis in fish cells. In addition, Val1686 alone was sufficient to induce cell rounding and apoptosis as evidenced by the transfection of Val1686 into fish cells. Importantly, the Fic-domain essential for cell rounding activity was equally important to activation of apoptosis of fish cells, indicating that apoptosis is a downstream event of Val1686-dependent GTPase inhibition. V. alginolyticus infection likely activates JNK and ERK pathways with sequential activation of caspases (caspase-8/-10, -9 and -3) and subsequent apoptosis. Val1680 contributed to T3SS-dependent lysis of fish cells in V. alginolyticus, but did not induce autophagy as has been reported for its homologue (VopQ) in V. parahaemolyticus. Together, Val1686 and Val1680 work together to induce apoptosis, cell rounding and cell lysis of V. alginolyticus-infected fish cells. These findings provide new insights into the mechanism of cell death caused by T3SS of V. alginolyticus.
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Affiliation(s)
- Zhe Zhao
- a Institute of Marine Biology, College of Oceanography, Hohai University , Nanjing , Jiangsu, PR China.,b Key Laboratory of Marine Bio-resources Sustainable Utilization, Key Laboratory of Applied Marine Biology of Guangdong Province, South China Sea Institute of Oceanology, Chinese Academy of Sciences , Guangzhou, Guangdong , PR China
| | - Jinxin Liu
- a Institute of Marine Biology, College of Oceanography, Hohai University , Nanjing , Jiangsu, PR China.,c Paul G. Allen School for Global Animal Health, Washington State University , Pullman , WA , U.S
| | - Yiqin Deng
- b Key Laboratory of Marine Bio-resources Sustainable Utilization, Key Laboratory of Applied Marine Biology of Guangdong Province, South China Sea Institute of Oceanology, Chinese Academy of Sciences , Guangzhou, Guangdong , PR China.,d Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences , Guangzhou, Guangdong , PR China
| | - Wen Huang
- b Key Laboratory of Marine Bio-resources Sustainable Utilization, Key Laboratory of Applied Marine Biology of Guangdong Province, South China Sea Institute of Oceanology, Chinese Academy of Sciences , Guangzhou, Guangdong , PR China
| | - Chunhua Ren
- b Key Laboratory of Marine Bio-resources Sustainable Utilization, Key Laboratory of Applied Marine Biology of Guangdong Province, South China Sea Institute of Oceanology, Chinese Academy of Sciences , Guangzhou, Guangdong , PR China
| | - Douglas R Call
- c Paul G. Allen School for Global Animal Health, Washington State University , Pullman , WA , U.S
| | - Chaoqun Hu
- b Key Laboratory of Marine Bio-resources Sustainable Utilization, Key Laboratory of Applied Marine Biology of Guangdong Province, South China Sea Institute of Oceanology, Chinese Academy of Sciences , Guangzhou, Guangdong , PR China
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Stradal TEB, Schelhaas M. Actin dynamics in host-pathogen interaction. FEBS Lett 2018; 592:3658-3669. [PMID: 29935019 PMCID: PMC6282728 DOI: 10.1002/1873-3468.13173] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 06/19/2018] [Accepted: 06/19/2018] [Indexed: 02/06/2023]
Abstract
The actin cytoskeleton and Rho GTPase signaling to actin assembly are prime targets of bacterial and viral pathogens, simply because actin is involved in all motile and membrane remodeling processes, such as phagocytosis, macropinocytosis, endocytosis, exocytosis, vesicular trafficking and membrane fusion events, motility, and last but not least, autophagy. This article aims at providing an overview of the most prominent pathogen‐induced or ‐hijacked actin structures, and an outlook on how future research might uncover additional, equally sophisticated interactions.
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Affiliation(s)
- Theresia E B Stradal
- Department of Cell Biology, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - Mario Schelhaas
- Institute of Cellular Virology, ZMBE, University of Münster, Germany
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37
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Ho M, Mettouchi A, Wilson BA, Lemichez E. CNF1-like deamidase domains: common Lego bricks among cancer-promoting immunomodulatory bacterial virulence factors. Pathog Dis 2018; 76:4992304. [PMID: 29733372 DOI: 10.1093/femspd/fty045] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 05/01/2018] [Indexed: 12/28/2022] Open
Abstract
Alterations of the cellular proteome over time due to spontaneous or toxin-mediated enzymatic deamidation of glutamine (Gln) and asparagine (Asn) residues contribute to bacterial infection and might represent a source of aging-related diseases. Here, we put into perspective what is known about the mode of action of the CNF1 toxin from pathogenic Escherichia coli, a paradigm of bacterial deamidases that activate Rho GTPases, to illustrate the importance of determining whether exposure to these factors are risk factors in the etiology age-related diseases, such as cancer. In particular, through in silico analysis of the distribution of the CNF1-like deamidase active site Gly-Cys-(Xaa)n-His sequence motif in bacterial genomes, we unveil the wide distribution of the super-family of CNF-like toxins and CNF-like deamidase domains among members of the Enterobacteriacae and in association with a large variety of toxin delivery systems. We extent our discussion with recent findings concerning cellular systems that control activated Rac1 GTPase stability and provide protection against cancer. These findings point to the urgency for developing holistic approaches toward personalized medicine that include monitoring for asymptomatic carriage of pathogenic toxin-producing bacteria and that ultimately might lead to improved public health and increased lifespans.
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Affiliation(s)
- Mengfei Ho
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Illinois 61801, USA
| | - Amel Mettouchi
- Bacterial Toxins Unit, Department of Microbiology, Institut Pasteur, 25 Rue du Docteur Roux, 75724 Paris, France
| | - Brenda A Wilson
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Illinois 61801, USA
| | - Emmanuel Lemichez
- Bacterial Toxins Unit, Department of Microbiology, Institut Pasteur, 25 Rue du Docteur Roux, 75724 Paris, France
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Valera FCP, Ruffin M, Adam D, Maillé É, Ibrahim B, Berube J, Rousseau S, Brochiero E, Desrosiers MY. Staphylococcus aureus impairs sinonasal epithelial repair: Effects in patients with chronic rhinosinusitis with nasal polyps and control subjects. J Allergy Clin Immunol 2018; 143:591-603.e3. [PMID: 29935218 DOI: 10.1016/j.jaci.2018.05.035] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 05/07/2018] [Accepted: 05/19/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND The effect of Staphylococcus aureus on nasal epithelial repair has never been assessed in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). OBJECTIVE This study aimed to determine whether (1) nasal epithelial cell cultures from patients with CRSwNP and control subjects repair differently; (2) S aureus exoproducts compromise nasal epithelial repair; (3) S aureus alters lamellipodial dynamics; and (4) deleterious effects could be counteracted by the Rho-associated coiled-coil kinase inhibitor Y-27632. METHODS Primary nasal epithelial cells (pNECs) collected during surgeries were cultured and injured under 3 conditions: (1) basal conditions, (2) exposed to S aureus exoproducts, and (3) exposed to S aureus exoproducts and Y-27632. Epithelial repair, lamellipodial dynamics, and cytoskeletal organization were assessed. RESULTS Under basal conditions, pNEC cultures from patients with CRSwNP presented significantly lower repair rates and reduced lamellipodial protrusion length and velocity than those from control subjects. S aureus exoproducts significantly decreased repair rates and protrusion dynamics in both control subjects and patients with CRSwNP; however, the effect of S aureus on cell protrusions was more sustained over time in patients with CRSwNP. Under basal conditions, immunofluorescence assays showed significantly reduced percentages of cells with lamellipodia at the wound edge in patients with CRSwNP compared with control subjects. S aureus altered cell polarity and decreased the percentage of cells with lamellipodia in both groups. Finally, Y-27632 prevented the deleterious effects of S aureus exoproducts on CRSwNP repair rates, as well as on lamellipodial dynamics and formation. CONCLUSIONS S aureus exoproducts significantly alter epithelial repair and lamellipodial dynamics on pNECs, and this impairment was more pronounced in patients with CRSwNP. Importantly, Y-27632 restored epithelial repair and lamellipodial dynamics in the presence of S aureus exoproducts.
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Affiliation(s)
- Fabiana C P Valera
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada; Division of Otorhinolaryngology, Ribeirão Preto Medical School, University of São Paulo (FMRP-USP), Ribeirão Preto, Brazil
| | - Manon Ruffin
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada; Département de Médecine, Université de Montréal, Montreal, Quebec, Canada
| | - Damien Adam
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada; Département de Médecine, Université de Montréal, Montreal, Quebec, Canada
| | - Émilie Maillé
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Badr Ibrahim
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada; Department of Otolaryngology, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, Quebec, Canada
| | - Julie Berube
- Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Simon Rousseau
- Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Emmanuelle Brochiero
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada; Département de Médecine, Université de Montréal, Montreal, Quebec, Canada
| | - Martin Y Desrosiers
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada; Department of Otolaryngology, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, Quebec, Canada.
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Woida PJ, Satchell KJF. Coordinated delivery and function of bacterial MARTX toxin effectors. Mol Microbiol 2017; 107:133-141. [PMID: 29114985 DOI: 10.1111/mmi.13875] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2017] [Indexed: 12/22/2022]
Abstract
Bacteria often coordinate virulence factors to fine-tune the host response during infection. These coordinated events can include toxins counteracting or amplifying effects of another toxin or though regulating the stability of virulence factors to remove their function once it is no longer needed. Multifunctional autoprocessing repeats-in toxin (MARTX) toxins are effector delivery toxins that form a pore into the plasma membrane of a eukaryotic cell to deliver multiple effector proteins into the cytosol of the target cell. The function of these proteins includes manipulating actin cytoskeletal dynamics, regulating signal transduction pathways and inhibiting host secretory pathways. Investigations into the molecular mechanisms of these effector domains are providing insight into how the function of some effectors overlap and regulate one another during infection. Coordinated crosstalk of effector function suggests that MARTX toxins are not simply a sum of all their parts. Instead, modulation of cell function by effector domains may depend on which other effector domain are co-delivered. Future studies will elucidate how these effectors interact with each other to modulate the bacterial host interaction.
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Affiliation(s)
- Patrick J Woida
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Karla J F Satchell
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
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Aktories K, Schwan C, Lang AE. ADP-Ribosylation and Cross-Linking of Actin by Bacterial Protein Toxins. Handb Exp Pharmacol 2017; 235:179-206. [PMID: 27316913 DOI: 10.1007/164_2016_26] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Actin and the actin cytoskeleton play fundamental roles in host-pathogen interactions. Proper function of the actin cytoskeleton is crucial for innate and acquired immune defense. Bacterial toxins attack the actin cytoskeleton by targeting regulators of actin. Moreover, actin is directly modified by various bacterial protein toxins and effectors, which cause ADP-ribosylation or cross-linking of actin. Modification of actin can result in inhibition or stimulation of actin polymerization. Toxins, acting directly on actin, are reviewed.
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Affiliation(s)
- Klaus Aktories
- Institute for Experimental and Clinical Pharmacology and Toxicology, Albert-Ludwigs-Universität Freiburg, Freiburg, 79104, Germany. .,Freiburg Institute of Advanced Studies (FRIAS), Albert-Ludwigs-Universität Freiburg, Freiburg, 79104, Germany.
| | - Carsten Schwan
- Institute for Experimental and Clinical Pharmacology and Toxicology, Albert-Ludwigs-Universität Freiburg, Freiburg, 79104, Germany
| | - Alexander E Lang
- Institute for Experimental and Clinical Pharmacology and Toxicology, Albert-Ludwigs-Universität Freiburg, Freiburg, 79104, Germany
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41
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Differentiating Staphylococcus aureus from Escherichia coli mastitis: S. aureus triggers unbalanced immune-dampening and host cell invasion immediately after udder infection. Sci Rep 2017; 7:4811. [PMID: 28684793 PMCID: PMC5500526 DOI: 10.1038/s41598-017-05107-4] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 05/23/2017] [Indexed: 02/08/2023] Open
Abstract
The etiology determines quality and extent of the immune response after udder infection (mastitis). Infections with Gram negative bacteria (e.g. Escherichia coli) will quickly elicit strong inflammation of the udder, fully activate its immune defence via pathogen receptor driven activation of IκB/NF-κB signaling. This often eradicates the pathogen. In contrast, Gram-positive bacteria (e.g. Staphylococcus aureus) will slowly elicit a much weaker inflammation and immune response, frequently resulting in chronic infections. However, it was unclear which immune regulatory pathways are specifically triggered by S. aureus causing this partial immune subversion. We therefore compared in first lactating cows the earliest (1–3 h) udder responses against infection with mastitis causing pathogens of either species. Global transcriptome profiling, bioinformatics analysis and experimental validation of key aspects revealed as S. aureus infection specific features the (i) failure to activating IκB/NF-κB signaling; (ii) activation of the wnt/β-catenin cascade resulting in active suppression of NF-κB signaling and (iii) rearrangement of the actin-cytoskeleton through modulating Rho GTPase regulated pathways. This facilitates invasion of pathogens into host cells. Hence, S. aureus mastitis is characterized by eliciting unbalanced immune suppression rather than inflammation and invasion of S. aureus into the epithelial cells of the host causing sustained infection.
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The Molecular Basis of Toxins' Interactions with Intracellular Signaling via Discrete Portals. Toxins (Basel) 2017; 9:toxins9030107. [PMID: 28300784 PMCID: PMC5371862 DOI: 10.3390/toxins9030107] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 03/02/2017] [Accepted: 03/04/2017] [Indexed: 12/20/2022] Open
Abstract
An understanding of the molecular mechanisms by which microbial, plant or animal-secreted toxins exert their action provides the most important element for assessment of human health risks and opens new insights into therapies addressing a plethora of pathologies, ranging from neurological disorders to cancer, using toxinomimetic agents. Recently, molecular and cellular biology dissecting tools have provided a wealth of information on the action of these diverse toxins, yet, an integrated framework to explain their selective toxicity is still lacking. In this review, specific examples of different toxins are emphasized to illustrate the fundamental mechanisms of toxicity at different biochemical, molecular and cellular- levels with particular consideration for the nervous system. The target of primary action has been highlighted and operationally classified into 13 sub-categories. Selected examples of toxins were assigned to each target category, denominated as portal, and the modulation of the different portal’s signaling was featured. The first portal encompasses the plasma membrane lipid domains, which give rise to pores when challenged for example with pardaxin, a fish toxin, or is subject to degradation when enzymes of lipid metabolism such as phospholipases A2 (PLA2) or phospholipase C (PLC) act upon it. Several major portals consist of ion channels, pumps, transporters and ligand gated ionotropic receptors which many toxins act on, disturbing the intracellular ion homeostasis. Another group of portals consists of G-protein-coupled and tyrosine kinase receptors that, upon interaction with discrete toxins, alter second messengers towards pathological levels. Lastly, subcellular organelles such as mitochondria, nucleus, protein- and RNA-synthesis machineries, cytoskeletal networks and exocytic vesicles are also portals targeted and deregulated by other diverse group of toxins. A fundamental concept can be drawn from these seemingly different toxins with respect to the site of action and the secondary messengers and signaling cascades they trigger in the host. While the interaction with the initial portal is largely determined by the chemical nature of the toxin, once inside the cell, several ubiquitous second messengers and protein kinases/ phosphatases pathways are impaired, to attain toxicity. Therefore, toxins represent one of the most promising natural molecules for developing novel therapeutics that selectively target the major cellular portals involved in human physiology and diseases.
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Tan S, Yao J, Zhou T, Liu S, Yuan Z, Tian C, Li Q, Liu Z. Identification, annotation and expression analysis of 29 Rho GTPase genes from channel catfish (Ictalurus punctatus) after bacterial infections. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 67:445-451. [PMID: 27765605 DOI: 10.1016/j.dci.2016.10.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 10/14/2016] [Accepted: 10/14/2016] [Indexed: 06/06/2023]
Abstract
The Rho family GTPases are a group of small monomeric G proteins, which are molecular switches in signaling pathways. They have been known to regulate a diverse range of cellular processes including actin cytoskeleton rearrangement and microtubule dynamics. In particular, their participations in immune responses are also significant. However, little information of the Rho GTPases is available in teleost including channel catfish, an economically important species and one of the best teleost models forimmunological research. In this study, Rho GTPase genes were identified from channel catfish and well annotated by phylogenetic and syntenic analyses. Their expression profiles were determined in channel catfish healthy tissues and infected tissues. Altogether seven Rho GTPase genes were significantly regulated after bacterial infection, with six genes in the gill after Flavobacterium columnare challenge and two genes in the intestine in response to Edwardsiella ictaluri. All the differentially expressed genes were up-regulated soon after bacterial infection. Different expression patterns between the two experiments were observed, which may be attributed to tissue-specific regulation or pathogen-specific regulation. These results suggested that Rho GTPases play important roles in immune responses to bacterial pathogens, setting a foundation for future investigation on Rho GTPases.
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Affiliation(s)
- Suxu Tan
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
| | - Jun Yao
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
| | - Tao Zhou
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
| | - Shikai Liu
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
| | - Zihao Yuan
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
| | - Changxu Tian
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
| | - Qi Li
- The Shellfish Genetics and Breeding Laboratory, Fisheries College, Ocean University of China, Qingdao 266003, China
| | - Zhanjiang Liu
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA.
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Role of p38 alpha/beta MAP Kinase in Cell Susceptibility to Clostridium sordellii Lethal Toxin and Clostridium difficile Toxin B. Toxins (Basel) 2016; 9:toxins9010002. [PMID: 28025502 PMCID: PMC5308236 DOI: 10.3390/toxins9010002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 12/16/2016] [Accepted: 12/19/2016] [Indexed: 12/27/2022] Open
Abstract
Lethal Toxin from Clostridium sordellii (TcsL), which is casually involved in the toxic shock syndrome and in gas gangrene, enters its target cells by receptor-mediated endocytosis. Inside the cell, TcsL mono-O-glucosylates and thereby inactivates Rac/Cdc42 and Ras subtype GTPases, resulting in actin reorganization and an activation of p38 MAP kinase. While a role of p38 MAP kinase in TcsL-induced cell death is well established, data on a role of p38 MAP kinase in TcsL-induced actin reorganization are not available. In this study, TcsL-induced Rac/Cdc42 glucosylation and actin reorganization are differentially analyzed in p38alpha−/− MSCV empty vector MEFs and the corresponding cell line with reconstituted p38alpha expression (p38alpha−/− MSCV p38alpha MEFs). Genetic deletion of p38alpha results in reduced susceptibility of cells to TcsL-induced Rac/Cdc42 glucosylation and actin reorganization. Furthermore, SB203580, a pyridinyl imidazole inhibitor of p38alpha/beta MAP kinase, also protects cells from TcsL-induced effects in both p38−/− MSCV empty vector MEFs and in p38alpha−/− MSCV p38alpha MEFs, suggesting that inhibition of p38beta contributes to the protective effect of SB203580. In contrast, the effects of the related C. difficile Toxin B are responsive neither to SB203580 treatment nor to p38alpha deletion. In conclusion, the protective effects of SB203580 and of p38alpha deletion are likely not based on inhibition of the toxins’ glucosyltransferase activity rather than on inhibited endocytic uptake of specifically TcsL into target cells.
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Guven-Maiorov E, Tsai CJ, Nussinov R. Pathogen mimicry of host protein-protein interfaces modulates immunity. Semin Cell Dev Biol 2016; 58:136-45. [DOI: 10.1016/j.semcdb.2016.06.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 06/02/2016] [Accepted: 06/06/2016] [Indexed: 12/21/2022]
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Taieb F, Petit C, Nougayrède JP, Oswald E. The Enterobacterial Genotoxins: Cytolethal Distending Toxin and Colibactin. EcoSal Plus 2016; 7. [PMID: 27419387 DOI: 10.1128/ecosalplus.esp-0008-2016] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Indexed: 06/06/2023]
Abstract
While the DNA damage induced by ionizing radiation and by many chemical compounds and drugs is well characterized, the genotoxic insults inflicted by bacteria are only scarcely documented. However, accumulating evidence indicates that we are exposed to bacterial genotoxins. The prototypes of such bacterial genotoxins are the Cytolethal Distending Toxins (CDTs) produced by Escherichia coli and Salmonella enterica serovar Typhi. CDTs display the DNase structure fold and activity, and induce DNA strand breaks in the intoxicated host cell nuclei. E. coli and certain other Enterobacteriaceae species synthesize another genotoxin, colibactin. Colibactin is a secondary metabolite, a hybrid polyketide/nonribosomal peptide compound synthesized by a complex biosynthetic machinery. In this review, we summarize the current knowledge on CDT and colibactin produced by E. coli and/or Salmonella Typhi. We describe their prevalence, genetic determinants, modes of action, and impact in infectious diseases or gut colonization, and discuss the possible involvement of these genotoxigenic bacteria in cancer.
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Affiliation(s)
- Frederic Taieb
- Institut de Recherche en Santé Digestive (IRSD), INRA UMR1416, INSERM U1220, Université de Toulouse, CHU Purpan, Toulouse, FRANCE
| | - Claude Petit
- Institut de Recherche en Santé Digestive (IRSD), INRA UMR1416, INSERM U1220, Université de Toulouse, CHU Purpan, Toulouse, FRANCE
| | - Jean-Philippe Nougayrède
- Institut de Recherche en Santé Digestive (IRSD), INRA UMR1416, INSERM U1220, Université de Toulouse, CHU Purpan, Toulouse, FRANCE
| | - Eric Oswald
- Institut de Recherche en Santé Digestive (IRSD), INRA UMR1416, INSERM U1220, Université de Toulouse, CHU Purpan, Toulouse, FRANCE
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47
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Rho-modifying bacterial protein toxins from Photorhabdus species. Toxicon 2016; 116:17-22. [DOI: 10.1016/j.toxicon.2015.05.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 05/15/2015] [Accepted: 05/26/2015] [Indexed: 02/04/2023]
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Di Bella S, Ascenzi P, Siarakas S, Petrosillo N, di Masi A. Clostridium difficile Toxins A and B: Insights into Pathogenic Properties and Extraintestinal Effects. Toxins (Basel) 2016; 8:E134. [PMID: 27153087 PMCID: PMC4885049 DOI: 10.3390/toxins8050134] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 04/22/2016] [Accepted: 04/25/2016] [Indexed: 02/06/2023] Open
Abstract
Clostridium difficile infection (CDI) has significant clinical impact especially on the elderly and/or immunocompromised patients. The pathogenicity of Clostridium difficile is mainly mediated by two exotoxins: toxin A (TcdA) and toxin B (TcdB). These toxins primarily disrupt the cytoskeletal structure and the tight junctions of target cells causing cell rounding and ultimately cell death. Detectable C. difficile toxemia is strongly associated with fulminant disease. However, besides the well-known intestinal damage, recent animal and in vitro studies have suggested a more far-reaching role for these toxins activity including cardiac, renal, and neurologic impairment. The creation of C. difficile strains with mutations in the genes encoding toxin A and B indicate that toxin B plays a major role in overall CDI pathogenesis. Novel insights, such as the role of a regulator protein (TcdE) on toxin production and binding interactions between albumin and C. difficile toxins, have recently been discovered and will be described. Our review focuses on the toxin-mediated pathogenic processes of CDI with an emphasis on recent studies.
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Affiliation(s)
- Stefano Di Bella
- 2nd Infectious Diseases Division, National Institute for Infectious Diseases "L. Spallanzani", Rome 00149, Italy.
| | - Paolo Ascenzi
- Department of Science, Roma Tre University, Rome 00154, Italy.
| | - Steven Siarakas
- Department of Microbiology and Infectious Diseases, Concord Repatriation General Hospital, Sydney 2139, Australia.
| | - Nicola Petrosillo
- 2nd Infectious Diseases Division, National Institute for Infectious Diseases "L. Spallanzani", Rome 00149, Italy.
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Popa C, Coll NS, Valls M, Sessa G. Yeast as a Heterologous Model System to Uncover Type III Effector Function. PLoS Pathog 2016; 12:e1005360. [PMID: 26914889 PMCID: PMC4767418 DOI: 10.1371/journal.ppat.1005360] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Type III effectors (T3E) are key virulence proteins that are injected by bacterial pathogens inside the cells of their host to subvert cellular processes and contribute to disease. The budding yeast Saccharomyces cerevisiae represents an important heterologous system for the functional characterisation of T3E proteins in a eukaryotic environment. Importantly, yeast contains eukaryotic processes with low redundancy and are devoid of immunity mechanisms that counteract T3Es and mask their function. Expression in yeast of effectors from both plant and animal pathogens that perturb conserved cellular processes often resulted in robust phenotypes that were exploited to elucidate effector functions, biochemical properties, and host targets. The genetic tractability of yeast and its amenability for high-throughput functional studies contributed to the success of this system that, in recent years, has been used to study over 100 effectors. Here, we provide a critical view on this body of work and describe advantages and limitations inherent to the use of yeast in T3E research. “Favourite” targets of T3Es in yeast are cytoskeleton components and small GTPases of the Rho family. We describe how mitogen-activated protein kinase (MAPK) signalling, vesicle trafficking, membrane structures, and programmed cell death are also often altered by T3Es in yeast and how this reflects their function in the natural host. We describe how effector structure–function studies and analysis of candidate targeted processes or pathways can be carried out in yeast. We critically analyse technologies that have been used in yeast to assign biochemical functions to T3Es, including transcriptomics and proteomics, as well as suppressor, gain-of-function, or synthetic lethality screens. We also describe how yeast can be used to select for molecules that block T3E function in search of new antibacterial drugs with medical applications. Finally, we provide our opinion on the limitations of S. cerevisiae as a model system and its most promising future applications.
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Affiliation(s)
- Crina Popa
- Genetics Department, Universitat de Barcelona, Barcelona, Catalonia, Spain
- Centre for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Catalonia, Spain
| | - Núria S. Coll
- Centre for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Catalonia, Spain
| | - Marc Valls
- Genetics Department, Universitat de Barcelona, Barcelona, Catalonia, Spain
- Centre for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Catalonia, Spain
- * E-mail: (GS); (MV)
| | - Guido Sessa
- Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv, Israel
- * E-mail: (GS); (MV)
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Stradal TEB, Costa SCP. Type III Secreted Virulence Factors Manipulating Signaling to Actin Dynamics. Curr Top Microbiol Immunol 2016; 399:175-199. [PMID: 27744505 DOI: 10.1007/82_2016_35] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A key aspect of bacterial pathogenesis is the colonization and persistence within the host and, later on, its dissemination to new niches. During evolution, bacteria developed a myriad of virulence mechanisms to usurp the host's sophisticated defense mechanisms in order to establish their colonization niche. Elucidation of the highly dynamic and complex interactions between host and pathogens remains an important field of study. Here, we highlight the conserved manipulation of the actin cytoskeleton by some Gram-negative gastrointestinal pathogens, addressing the role of type III secreted bacterial GEFs at the different steps of pathogenesis. As a final topic, we review cytoskeleton dynamics induced by EPEC/EHEC strains for pedestal formation.
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Affiliation(s)
- Theresia E B Stradal
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstr. 7, 38124, Baunschweig, Germany.
| | - Sonia C P Costa
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstr. 7, 38124, Baunschweig, Germany
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