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N’Tcha C, Sina H, Bourobou DN, Hoteyi SMI, Boya B, Agnimonhan R, Mavoungou JF, Adjanohoun A, Babalola OO, Baba-Moussa L. Resistance and Biofilm Production Profile of Potential Isolated from Kpètè-Kpètè Used to Produce Traditional Fermented Beer. Microorganisms 2023; 11:1939. [PMID: 37630499 PMCID: PMC10459457 DOI: 10.3390/microorganisms11081939] [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: 05/25/2023] [Revised: 07/16/2023] [Accepted: 07/26/2023] [Indexed: 08/27/2023] Open
Abstract
This study aimed to characterize the pathogenicity of bacteria isolated from the starter of two traditional beers produced and consumed in Benin. After standard microbial identification, species were identified by specific biochemical tests such as catalase, coagulase, and API 20 E. Antibiotic sensitivity was tested according to the French Society of Microbiology Antibiogram Committee. The crystal violet microplate technique evaluated the biofilm production and conventional PCR was used to identify genes encoding virulence and macrolide resistance. According to our data, the traditional starter known as kpètè-kpètè that is used to produce beer is contaminated by Enterobacteriaceae and staphylococci species. Thus, 28.43% of the isolated bacteria were coagulase-negative staphylococci (CNS), and 10.93% coagulase-positive staphylococci (CPS). Six species such as Klebsiella terrigena (1.38%), Enterobacter aerogens (4.14%), Providencia rettgeri (5.51%), Chryseomonas luteola (6.89%), Serratia rubidae (15.16%), and Enterobacter cloacae (27.56%) were identified among Enterobacteriaceae. Those bacterial strains are multi-resistant to conventional antibiotics. The hight capability of produced biofilms was recorded with Enterobacter aerogens, Klebsiella terrigena (100%), Providencia rettgeri (75%), and Staphylococcus spp (60%). Enterobacter cloacae (4%) and coagulase-negative Staphylococcus (5.55%) harbor the macrolide resistance gene. For other strains, these genes were not detected. Foods contaminated with bacteria resistant to antibiotics and carrying a virulence gene could constitute a potential public health problem. There is a need to increase awareness campaigns on hygiene rules in preparing and selling these traditional beers.
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Affiliation(s)
- Christine N’Tcha
- Laboratory of Biology and Molecular Typing in Microbiology, Department of Biochemistry and Cell Biology, University of Abomey-Calavi, Abomey-Calavi 05 BP 1604, Benin; (C.N.); (H.S.); (S.M.I.H.); (B.B.); (R.A.)
| | - Haziz Sina
- Laboratory of Biology and Molecular Typing in Microbiology, Department of Biochemistry and Cell Biology, University of Abomey-Calavi, Abomey-Calavi 05 BP 1604, Benin; (C.N.); (H.S.); (S.M.I.H.); (B.B.); (R.A.)
| | - Dyana Ndiade Bourobou
- Institut de Recherches Agronomiques et Forestières (IRAF), BP.12978 Gros-Bouquet, Libreville B.P. 16 182, Gabon; (D.N.B.); (J.F.M.)
| | - S. M. Ismaël Hoteyi
- Laboratory of Biology and Molecular Typing in Microbiology, Department of Biochemistry and Cell Biology, University of Abomey-Calavi, Abomey-Calavi 05 BP 1604, Benin; (C.N.); (H.S.); (S.M.I.H.); (B.B.); (R.A.)
| | - Bawa Boya
- Laboratory of Biology and Molecular Typing in Microbiology, Department of Biochemistry and Cell Biology, University of Abomey-Calavi, Abomey-Calavi 05 BP 1604, Benin; (C.N.); (H.S.); (S.M.I.H.); (B.B.); (R.A.)
| | - Raoul Agnimonhan
- Laboratory of Biology and Molecular Typing in Microbiology, Department of Biochemistry and Cell Biology, University of Abomey-Calavi, Abomey-Calavi 05 BP 1604, Benin; (C.N.); (H.S.); (S.M.I.H.); (B.B.); (R.A.)
| | - Jacques François Mavoungou
- Institut de Recherches Agronomiques et Forestières (IRAF), BP.12978 Gros-Bouquet, Libreville B.P. 16 182, Gabon; (D.N.B.); (J.F.M.)
| | - Adolphe Adjanohoun
- National Agronomic Research Institute of Benin, Cotonou 01 BP 884, Benin;
| | - Olubukola Oluranti Babalola
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho 2735, South Africa
| | - Lamine Baba-Moussa
- Laboratory of Biology and Molecular Typing in Microbiology, Department of Biochemistry and Cell Biology, University of Abomey-Calavi, Abomey-Calavi 05 BP 1604, Benin; (C.N.); (H.S.); (S.M.I.H.); (B.B.); (R.A.)
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Lafrance AE, Chimalapati S, Garcia Rodriguez N, Kinch LN, Kaval KG, Orth K. Enzymatic Specificity of Conserved Rho GTPase Deamidases Promotes Invasion of Vibrio parahaemolyticus at the Expense of Infection. mBio 2022; 13:e0162922. [PMID: 35862776 PMCID: PMC9426531 DOI: 10.1128/mbio.01629-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 06/17/2022] [Indexed: 11/23/2022] Open
Abstract
Vibrio parahaemolyticus is among the leading causes of bacterial seafood-borne acute gastroenteritis. Like many intracellular pathogens, V. parahaemolyticus invades host cells during infection by deamidating host small Rho GTPases. The Rho GTPase deamidating activity of VopC, a type 3 secretion system (T3SS) translocated effector, drives V. parahaemolyticus invasion. The intracellular pathogen uropathogenic Escherichia coli (UPEC) invades host cells by secreting a VopC homolog, the secreted toxin cytotoxic necrotizing factor 1 (CNF1). Because of the homology between VopC and CNF1, we hypothesized that topical application of CNF1 during V. parahaemolyticus infection could supplement VopC activity. Here, we demonstrate that CNF1 improves the efficiency of V. parahaemolyticus invasion, a bottleneck in V. parahaemolyticus infection, across a range of doses. CNF1 increases V. parahaemolyticus invasion independent of both VopC and the T3SS altogether but leaves a disproportionate fraction of intracellular bacteria unable to escape the endosome and complete their infection cycle. This phenomenon holds true in the presence or absence of VopC but is particularly pronounced in the absence of a T3SS. The native VopC, by contrast, promotes a far less efficient invasion but permits the majority of internalized bacteria to escape the endosome and complete their infection cycle. These studies highlight the significance of enzymatic specificity during infection, as virulence factors (VopC and CNF1 in this instance) with similarities in function (bacterial uptake), catalytic activity (deamidation), and substrates (Rho GTPases) are not sufficiently interchangeable for mediating a successful invasion for neighboring bacterial pathogens. IMPORTANCE Many species of intracellular bacterial pathogens target host small Rho GTPases to initiate invasion, including the human pathogens Vibrio parahaemolyticus and uropathogenic Escherichia coli (UPEC). The type three secretion system (T3SS) effector VopC of V. parahaemolyticus promotes invasion through the deamidation of Rac1 and CDC42 in the host, whereas the secreted toxin cytotoxic necrotizing factor 1 (CNF1) drives UPEC's internalization through the deamidation of Rac1, CDC42, and RhoA. Despite these similarities in the catalytic activity of CNF1 and VopC, we observed that the two enzymes were not interchangeable. Although CNF1 increased V. parahaemolyticus endosomal invasion, most intracellular V. parahaemolyticus aborted their infection cycle and remained trapped in endosomes. Our findings illuminate how the precise biochemical fine-tuning of T3SS effectors is essential for efficacious pathogenesis. Moreover, they pave the way for future investigations into the biochemical mechanisms underpinning V. parahaemolyticus endosomal escape and, more broadly, the regulation of successful pathogenesis.
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Affiliation(s)
- Alexander E. Lafrance
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Suneeta Chimalapati
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Nalleli Garcia Rodriguez
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Lisa N. Kinch
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Karan Gautam Kaval
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Kim Orth
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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The Cytotoxic Necrotizing Factors (CNFs)-A Family of Rho GTPase-Activating Bacterial Exotoxins. Toxins (Basel) 2021; 13:toxins13120901. [PMID: 34941738 PMCID: PMC8709095 DOI: 10.3390/toxins13120901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 11/29/2021] [Accepted: 12/01/2021] [Indexed: 11/17/2022] Open
Abstract
The cytotoxic necrotizing factors (CNFs) are a family of Rho GTPase-activating single-chain exotoxins that are produced by several Gram-negative pathogenic bacteria. Due to the pleiotropic activities of the targeted Rho GTPases, the CNFs trigger multiple signaling pathways and host cell processes with diverse functional consequences. They influence cytokinesis, tissue integrity, cell barriers, and cell death, as well as the induction of inflammatory and immune cell responses. This has an enormous influence on host-pathogen interactions and the severity of the infection. The present review provides a comprehensive insight into our current knowledge of the modular structure, cell entry mechanisms, and the mode of action of this class of toxins, and describes their influence on the cell, tissue/organ, and systems levels. In addition to their toxic functions, possibilities for their use as drug delivery tool and for therapeutic applications against important illnesses, including nervous system diseases and cancer, have also been identified and are discussed.
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Role of the Yersinia pseudotuberculosis Virulence Plasmid in Pathogen-Phagocyte Interactions in Mesenteric Lymph Nodes. EcoSal Plus 2021; 9:eESP00142021. [PMID: 34910573 DOI: 10.1128/ecosalplus.esp-0014-2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Yersinia pseudotuberculosis is an Enterobacteriaceae family member that is commonly transmitted by the fecal-oral route to cause infections. From the small intestine, Y. pseudotuberculosis can invade through Peyer's patches and lymph vessels to infect the mesenteric lymph nodes (MLNs). Infection of MLNs by Y. pseudotuberculosis results in the clinical presentation of mesenteric lymphadenitis. MLNs are important for immune responses to intestinal pathogens and microbiota in addition to their clinical relevance to Y. pseudotuberculosis infections. A characteristic of Y. pseudotuberculosis infection in MLNs is the formation of pyogranulomas. Pyogranulomas are composed of neutrophils, inflammatory monocytes, and lymphocytes surrounding extracellular microcolonies of Y. pseudotuberculosis. Key elements of the complex pathogen-host interaction in MLNs have been identified using mouse infection models. Y. pseudotuberculosis requires the virulence plasmid pYV to induce the formation of pyogranulomas in MLNs. The YadA adhesin and the Ysc-Yop type III secretion system (T3SS) are encoded on pYV. YadA mediates bacterial binding to host receptors, which engages the T3SS to preferentially translocate seven Yop effectors into phagocytes. The effectors promote pathogenesis by blocking innate immune defenses such as superoxide production, degranulation, and inflammasome activation, resulting in survival and growth of Y. pseudotuberculosis. On the other hand, certain effectors can trigger immune defenses in phagocytes. For example, YopJ triggers activation of caspase-8 and an apoptotic cell death response in monocytes within pyogranulomas that limits dissemination of Y. pseudotuberculosis from MLNs to the bloodstream. YopE can be processed as an antigen by phagocytes in MLNs, resulting in T and B cell responses to Y. pseudotuberculosis. Immune responses to Y. pseudotuberculosis in MLNs can also be detrimental to the host in the form of chronic lymphadenopathy. This review focuses on interactions between Y. pseudotuberculosis and phagocytes mediated by pYV that concurrently promote pathogenesis and host defense in MLNs. We propose that MLN pyogranulomas are immunological arenas in which opposing pYV-driven forces determine the outcome of infection in favor of the pathogen or host.
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Morgan RN, Saleh SE, Farrag HA, Aboulwafa MM. Bacterial cyclomodulins: types and roles in carcinogenesis. Crit Rev Microbiol 2021; 48:42-66. [PMID: 34265231 DOI: 10.1080/1040841x.2021.1944052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Various studies confirmed that bacterial infections contribute to carcinogenesis through the excessive accumulation of reactive oxygen species (ROS) and the expression of toxins that disrupt the cell cycle phases, cellular regulatory mechanisms and stimulate the production of tumorigenic inflammatory mediators. These toxins mimic carcinogens which act upon key cellular targets and result in mutations and genotoxicities. The cyclomodulins are bacterial toxins that incur cell cycle modulating effects rendering the expressing bacterial species of high carcinogenic potentiality. They are either cellular proliferating or cell cycle arrest cyclomodulins. Notably, cyclomodulins expressing bacterial species have been linked to different human carcinomas. For instance, Escherichia coli species producing the colibactin were highly prevalent among colorectal carcinoma patients, CagA+ Helicobacter pylori species were associated with MALT lymphomas and gastric carcinomas and Salmonella species producing CdtB were linked to hepatobiliary carcinomas. These species stimulated the overgrowth of pre-existing carcinomas and induced hyperplasia in in vivo animal models suggesting a role for the cyclomodulins in carcinogenesis. Wherefore, the prevalence and mode of action of these toxins were the focus of many researchers and studies. This review discusses different types of bacterial cyclomodulins highlighting their mode of action and possible role in carcinogenesis.
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Affiliation(s)
- Radwa N Morgan
- Drug radiation research Department, Egyptian Atomic Energy Authority (EAEA), National Center for Radiation Research and Technology (NCRRT), Cairo, Egypt
| | - Sarra E Saleh
- Faculty of Pharmacy, Microbiology and Immunology Department, Ain Shams University, Cairo, Egypt
| | - Hala A Farrag
- Drug radiation research Department, Egyptian Atomic Energy Authority (EAEA), National Center for Radiation Research and Technology (NCRRT), Cairo, Egypt
| | - Mohammad M Aboulwafa
- Faculty of Pharmacy, Microbiology and Immunology Department, Ain Shams University, Cairo, Egypt.,Faculty of Pharmacy, King Salman International University, Ras-Sedr, Egypt
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Somova LM, Antonenko FF, Timchenko NF, Lyapun IN. Far Eastern Scarlet-Like Fever is a Special Clinical and Epidemic Manifestation of Yersinia pseudotuberculosis Infection in Russia. Pathogens 2020; 9:E436. [PMID: 32498317 PMCID: PMC7350351 DOI: 10.3390/pathogens9060436] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 05/25/2020] [Accepted: 05/30/2020] [Indexed: 01/21/2023] Open
Abstract
Pseudotuberculosis in humans until the 1950s was found in different countries of the world as a rare sporadic disease that occurred in the form of acute appendicitis and mesenteric lymphadenitis. In Russia and Japan, the Yersinia pseudotuberculosis (Y. pseudotuberculosis) infection often causes outbreaks of the disease with serious systemic inflammatory symptoms, and this variant of the disease has been known since 1959 as Far Eastern Scarlet-like Fever (FESLF). Russian researchers have proven that the FESLF pathogen is associated with a concrete clonal line of Y. pseudotuberculosis, characterized by a specific plasmid profile (pVM82, pYV 48 MDa), sequence (2ST) and yadA gene allele (1st allele). This review summarized the most important achievements in the study of FESLF since its discovery in the Far East. It has been established that the FESLF causative agent is characterized by a unique phenomenon of psychrophilicity, which consists of its ability to reproduce in the environment with its biologically low and variable temperature (4-12 °C), at which the pathogen multiplies and accumulates while maintaining or increasing its virulence, which ensures the emergence and development of the epidemic process. The key genetic and biochemical mechanisms of Y. pseudotuberculosis adaptation to changing environmental conditions were characterized, and the morphological manifestations of the adaptive variability of these bacteria in different conditions of their habitat were revealed. The main features of the pathogenesis and morphogenesis of FESLF, including those associated with the Y. pseudotuberculosis toxigenicity, were presented. The pathogenetic value of the plasmid PVM82, found only in the FESLF pathogen, was shown.
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Affiliation(s)
- Larisa M. Somova
- Somov Research Institute of Epidemiology and Microbiology, Ministry of Science and Higher Education, 690087 Vladivostok, Russia; (N.F.T.); (I.N.L.)
| | - Fedor F. Antonenko
- Russian Scientific Center for Roentgen-Radiology, Ministry of Health, 117997 Moscow, Russia;
| | - Nelly F. Timchenko
- Somov Research Institute of Epidemiology and Microbiology, Ministry of Science and Higher Education, 690087 Vladivostok, Russia; (N.F.T.); (I.N.L.)
| | - Irina N. Lyapun
- Somov Research Institute of Epidemiology and Microbiology, Ministry of Science and Higher Education, 690087 Vladivostok, Russia; (N.F.T.); (I.N.L.)
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Twittenhoff C, Heroven AK, Mühlen S, Dersch P, Narberhaus F. An RNA thermometer dictates production of a secreted bacterial toxin. PLoS Pathog 2020; 16:e1008184. [PMID: 31951643 PMCID: PMC6992388 DOI: 10.1371/journal.ppat.1008184] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 01/30/2020] [Accepted: 11/01/2019] [Indexed: 02/06/2023] Open
Abstract
Frequent transitions of bacterial pathogens between their warm-blooded host and external reservoirs are accompanied by abrupt temperature shifts. A temperature of 37°C serves as reliable signal for ingestion by a mammalian host, which induces a major reprogramming of bacterial gene expression and metabolism. Enteric Yersiniae are Gram-negative pathogens accountable for self-limiting gastrointestinal infections. Among the temperature-regulated virulence genes of Yersinia pseudotuberculosis is cnfY coding for the cytotoxic necrotizing factor (CNFY), a multifunctional secreted toxin that modulates the host’s innate immune system and contributes to the decision between acute infection and persistence. We report that the major determinant of temperature-regulated cnfY expression is a thermo-labile RNA structure in the 5’-untranslated region (5’-UTR). Various translational gene fusions demonstrated that this region faithfully regulates translation initiation regardless of the transcription start site, promoter or reporter strain. RNA structure probing revealed a labile stem-loop structure, in which the ribosome binding site is partially occluded at 25°C but liberated at 37°C. Consistent with translational control in bacteria, toeprinting (primer extension inhibition) experiments in vitro showed increased ribosome binding at elevated temperature. Point mutations locking the 5’-UTR in its 25°C structure impaired opening of the stem loop, ribosome access and translation initiation at 37°C. To assess the in vivo relevance of temperature control, we used a mouse infection model. Y. pseudotuberculosis strains carrying stabilized RNA thermometer variants upstream of cnfY were avirulent and attenuated in their ability to disseminate into mesenteric lymph nodes and spleen. We conclude with a model, in which the RNA thermometer acts as translational roadblock in a two-layered regulatory cascade that tightly controls provision of the CNFY toxin during acute infection. Similar RNA structures upstream of various cnfY homologs suggest that RNA thermosensors dictate the production of secreted toxins in a wide range of pathogens. Bacterial pathogens closely survey the ambient conditions and induce virulence genes only at appropriate conditions. Upon host contact, many pathogens secrete toxins in order to subvert host defense systems. We find that such a secreted toxin in enteropathogenic Yersinia pseudotuberculosis is produced only at host body temperature. This regulation depends on a temperature-responsive RNA structure, an RNA thermometer, in the 5’-untranslated region of the toxin mRNA, which prevents translation at low temperatures when the bacterium is outside the host. Preventing melting of the RNA structure at 37°C by nucleotide substitutions that stabilize base pairing resulted in avirulent Yersinia strains unable to infect mice. Given that similar RNA thermometer-like structures exist upstream of related toxin genes in various bacterial pathogens, we propose that RNA thermometer-mediated toxin production is an evolutionary conserved mechanism. Interfering with opening of such regulatory structures might thus be a promising strategy targeting a broad spectrum of bacterial pathogens.
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Affiliation(s)
| | - Ann Kathrin Heroven
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Sabrina Mühlen
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute of Infectiology, Center for Molecular Biology of Inflammation, University of Münster, Münster, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute of Infectiology, Center for Molecular Biology of Inflammation, University of Münster, Münster, Germany
| | - Franz Narberhaus
- Microbial Biology, Ruhr University Bochum, Bochum, Germany
- * E-mail:
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Psareva EK, Ermolaeva SA, Timchenko NF. A PCR System for Yersinia pseudotuberculosis Identification. MOLECULAR GENETICS MICROBIOLOGY AND VIROLOGY 2018. [DOI: 10.3103/s0891416818020106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Monnappa AK, Bari W, Seo JK, Mitchell RJ. The Cytotoxic Necrotizing Factor of Yersinia pseudotuberculosis (CNFy) is Carried on Extracellular Membrane Vesicles to Host Cells. Sci Rep 2018; 8:14186. [PMID: 30242257 PMCID: PMC6155089 DOI: 10.1038/s41598-018-32530-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 09/05/2018] [Indexed: 01/13/2023] Open
Abstract
In this study we show Yersinia pseudotuberculosis secretes membrane vesicles (MVs) that contain different proteins and virulence factors depending on the strain. Although MVs from Y. pseudotuberculosis YPIII and ATCC 29833 had many proteins in common (68.8% of all the proteins identified), those located in the outer membrane fraction differed significantly. For instance, the MVs from Y. pseudotuberculosis YPIII harbored numerous Yersinia outer proteins (Yops) while they were absent in the ATCC 29833 MVs. Another virulence factor found solely in the YPIII MVs was the cytotoxic necrotizing factor (CNFy), a toxin that leads to multinucleation of host cells. The ability of YPIII MVs to transport this toxin and its activity to host cells was verified using HeLa cells, which responded in a dose-dependent manner; nearly 70% of the culture was multinucleated after addition of 5 µg/ml of the purified YPIII MVs. In contrast, less than 10% were multinucleated when the ATCC 29833 MVs were added. Semi-quantification of CNFy within the YPIII MVs found this toxin is present at concentrations of 5 ~ 10 ng per µg of total MV protein, a concentration that accounts for the cellular responses seen.
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Affiliation(s)
- Ajay K Monnappa
- School of Life Sciences, Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
| | - Wasimul Bari
- School of Life Sciences, Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Jeong Kon Seo
- UNIST Central Research Facilities, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
| | - Robert J Mitchell
- School of Life Sciences, Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
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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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Heine W, Beckstette M, Heroven AK, Thiemann S, Heise U, Nuss AM, Pisano F, Strowig T, Dersch P. Loss of CNFY toxin-induced inflammation drives Yersinia pseudotuberculosis into persistency. PLoS Pathog 2018; 14:e1006858. [PMID: 29390040 PMCID: PMC5811047 DOI: 10.1371/journal.ppat.1006858] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 02/13/2018] [Accepted: 01/05/2018] [Indexed: 12/16/2022] Open
Abstract
Gastrointestinal infections caused by enteric yersiniae can become persistent and complicated by relapsing enteritis and severe autoimmune disorders. To establish a persistent infection, the bacteria have to cope with hostile surroundings when they transmigrate through the intestinal epithelium and colonize underlying gut-associated lymphatic tissues. How the bacteria gain a foothold in the face of host immune responses is poorly understood. Here, we show that the CNFY toxin, which enhances translocation of the antiphagocytic Yop effectors, induces inflammatory responses. This results in extensive tissue destruction, alteration of the intestinal microbiota and bacterial clearance. Suppression of CNFY function, however, increases interferon-γ-mediated responses, comprising non-inflammatory antimicrobial activities and tolerogenesis. This process is accompanied by a preterm reprogramming of the pathogen's transcriptional response towards persistence, which gives the bacteria a fitness edge against host responses and facilitates establishment of a commensal-type life style.
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Affiliation(s)
- Wiebke Heine
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Michael Beckstette
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ann Kathrin Heroven
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Sophie Thiemann
- Group Microbial Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ulrike Heise
- Group Mouse Pathology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Aaron Mischa Nuss
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Fabio Pisano
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Till Strowig
- Group Microbial Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
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Grabowski B, Schmidt MA, Rüter C. Immunomodulatory Yersinia outer proteins (Yops)-useful tools for bacteria and humans alike. Virulence 2017; 8:1124-1147. [PMID: 28296562 DOI: 10.1080/21505594.2017.1303588] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Human-pathogenic Yersinia produce plasmid-encoded Yersinia outer proteins (Yops), which are necessary to down-regulate anti-bacterial responses that constrict bacterial survival in the host. These Yops are effectively translocated directly from the bacterial into the target cell cytosol by the type III secretion system (T3SS). Cell-penetrating peptides (CPPs) in contrast are characterized by their ability to autonomously cross cell membranes and to transport cargo - independent of additional translocation systems. The recent discovery of bacterial cell-penetrating effector proteins (CPEs) - with the prototype being the T3SS effector protein YopM - established a new class of autonomously translocating immunomodulatory proteins. CPEs represent a vast source of potential self-delivering, anti-inflammatory therapeutics. In this review, we give an update on the characteristic features of the plasmid-encoded Yops and, based on recent findings, propose the further development of these proteins for potential therapeutic applications as natural or artificial cell-penetrating forms of Yops might be of value as bacteria-derived biologics.
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Affiliation(s)
- Benjamin Grabowski
- a Institute of Infectiology - Centre for Molecular Biology of Inflammation (ZMBE), University of Münster , Münster , Germany
| | - M Alexander Schmidt
- a Institute of Infectiology - Centre for Molecular Biology of Inflammation (ZMBE), University of Münster , Münster , Germany
| | - Christian Rüter
- a Institute of Infectiology - Centre for Molecular Biology of Inflammation (ZMBE), University of Münster , Münster , Germany
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13
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Aubert DF, Xu H, Yang J, Shi X, Gao W, Li L, Bisaro F, Chen S, Valvano MA, Shao F. A Burkholderia Type VI Effector Deamidates Rho GTPases to Activate the Pyrin Inflammasome and Trigger Inflammation. Cell Host Microbe 2016; 19:664-74. [PMID: 27133449 DOI: 10.1016/j.chom.2016.04.004] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 03/17/2016] [Accepted: 03/30/2016] [Indexed: 10/21/2022]
Abstract
Burkholderia cenocepacia is an opportunistic pathogen of the cystic fibrosis lung that elicits a strong inflammatory response. B. cenocepacia employs a type VI secretion system (T6SS) to survive in macrophages by disarming Rho-type GTPases, causing actin cytoskeletal defects. Here, we identified TecA, a non-VgrG T6SS effector responsible for actin disruption. TecA and other bacterial homologs bear a cysteine protease-like catalytic triad, which inactivates Rho GTPases by deamidating a conserved asparagine in the GTPase switch-I region. RhoA deamidation induces caspase-1 inflammasome activation, which is mediated by the familial Mediterranean fever disease protein Pyrin. In mouse infection, the deamidase activity of TecA is necessary and sufficient for B. cenocepacia-triggered lung inflammation and also protects mice from lethal B. cenocepacia infection. Therefore, Burkholderia TecA is a T6SS effector that modifies a eukaryotic target through an asparagine deamidase activity, which in turn elicits host cell death and inflammation through activation of the Pyrin inflammasome.
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Affiliation(s)
- Daniel F Aubert
- Department of Microbiology and Immunology, University of Western Ontario, London N6A 5C1, Canada
| | - Hao Xu
- National Institute of Biological Sciences, Beijing 102206, China
| | - Jieling Yang
- National Institute of Biological Sciences, Beijing 102206, China; National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xuyan Shi
- National Institute of Biological Sciences, Beijing 102206, China
| | - Wenqing Gao
- National Institute of Biological Sciences, Beijing 102206, China
| | - Lin Li
- National Institute of Biological Sciences, Beijing 102206, China
| | - Fabiana Bisaro
- Centre for Infection and Immunity, Queen's University Belfast, Belfast BT9 7AE, UK
| | - She Chen
- National Institute of Biological Sciences, Beijing 102206, China
| | - Miguel A Valvano
- Department of Microbiology and Immunology, University of Western Ontario, London N6A 5C1, Canada; Centre for Infection and Immunity, Queen's University Belfast, Belfast BT9 7AE, UK.
| | - Feng Shao
- National Institute of Biological Sciences, Beijing 102206, China; National Institute of Biological Sciences, Beijing, Collaborative Innovation Center for Cancer Medicine, Beijing 102206, China.
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14
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Antibodies against hemolysin and cytotoxic necrotizing factor type 1 (CNF1) reduce bladder inflammation in a mouse model of urinary tract infection with toxigenic uropathogenic Escherichia coli. Infect Immun 2015; 83:1661-73. [PMID: 25667267 DOI: 10.1128/iai.02848-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Uropathogenic Escherichia coli (UPEC) is the leading cause of cystitis. Cytotoxic necrotizing factor 1 (CNF1) and hemolysin (Hly) are toxins made by approximately 50% of UPEC isolates. CNF1 and Hly contribute to the robust inflammatory response in the bladders of mice challenged with UPEC strain CP9. We hypothesized that antibodies against CNF1 and/or Hly would reduce cystitis caused by CP9. To test this theory, we immunized female C3H/HeOuJ mice subcutaneously with a genetically derived Hly toxoid or genetically derived CNF1 toxoid plus sublethal doses of CNF1. We collected serum and observed increasing titers of specific and neutralizing antibodies against Hly or CNF1 over time. We challenged the mice intraurethrally with CP9 and euthanized them 24 h later. We observed 10-fold lower bacterial titers in the urine of Hly-immunized mice than in that of sham-immunized mice but no difference in kidney bacterial titers. Immunized mice also exhibited significantly less cystitis than sham-immunized mice. In CNF1-vaccinated mice, we detected neither a difference in urine or kidney bacterial titers nor a reduction in the severity of cystitis versus that of sham-immunized mice. We then passively administered an anti-CNF1 monoclonal antibody intraperitoneally to female C3H/HeOuJ mice prior to intraurethral challenge with CP9. Upon challenge, we noted no difference in colonization of the urine or kidney; however, cystitis was reduced significantly in mice treated with the anti-CNF1 antibody versus that in the bladders of mice given an isotype control antibody. Taken together, our data demonstrate that antibodies against CNF1 or Hly reduce the bladder pathology caused by UPEC.
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Influence of PhoP and intra-species variations on virulence of Yersinia pseudotuberculosis during the natural oral infection route. PLoS One 2014; 9:e103541. [PMID: 25075520 PMCID: PMC4116203 DOI: 10.1371/journal.pone.0103541] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 07/03/2014] [Indexed: 01/02/2023] Open
Abstract
The two-component regulatory system PhoP/PhoQ has been shown to (i) control expression of virulence-associated traits, (ii) confer survival and growth within macrophages and (iii) play a role in Yersinia infections. However, the influence of PhoP on virulence varied greatly between different murine models of infection and its role in natural oral infections with frequently used representative isolates of Y. pseudotuberculosis was unknown. To address this issue, we constructed an isogenic set of phoP+ and phoP− variants of strain IP32953 and YPIII and analyzed the impact of PhoP using in vitro functionality experiments and a murine oral infection model, whereby we tested for bacterial dissemination and influence on the host immune response. Our results revealed that PhoP has a low impact on virulence, lymphatic and systemic organ colonization, and on immune response modulation by IP32953 and YPIII, indicating that PhoP is not absolutely essential for oral infections but may be involved in fine-tuning the outcome. Our work further revealed certain strain-specific differences in virulence properties, which do not strongly rely on the function of PhoP, but affect tissue colonization, dissemination and/or persistence of the bacteria. Highlighted intra-species variations may provide a potential means to rapidly adjust to environmental changes inside and outside of the host.
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16
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What a difference a Dalton makes: bacterial virulence factors modulate eukaryotic host cell signaling systems via deamidation. Microbiol Mol Biol Rev 2014; 77:527-39. [PMID: 24006474 DOI: 10.1128/mmbr.00013-13] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pathogenic bacteria commonly deploy enzymes to promote virulence. These enzymes can modulate the functions of host cell targets. While the actions of some enzymes can be very obvious (e.g., digesting plant cell walls), others have more subtle activities. Depending on the lifestyle of the bacteria, these subtle modifications can be crucially important for pathogenesis. In particular, if bacteria rely on a living host, subtle mechanisms to alter host cellular function are likely to dominate. Several bacterial virulence factors have evolved to use enzymatic deamidation as a subtle posttranslational mechanism to modify the functions of host protein targets. Deamidation is the irreversible conversion of the amino acids glutamine and asparagine to glutamic acid and aspartic acid, respectively. Interestingly, all currently characterized bacterial deamidases affect the function of the target protein by modifying a single glutamine residue in the sequence. Deamidation of target host proteins can disrupt host signaling and downstream processes by either activating or inactivating the target. Despite the subtlety of this modification, it has been shown to cause dramatic, context-dependent effects on host cells. Several crystal structures of bacterial deamidases have been solved. All are members of the papain-like superfamily and display a cysteine-based catalytic triad. However, these proteins form distinct structural subfamilies and feature combinations of modular domains of various functions. Based on the diverse pathogens that use deamidation as a mechanism to promote virulence and the recent identification of multiple deamidases, it is clear that this enzymatic activity is emerging as an important and widespread feature in bacterial pathogenesis.
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17
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Schweer J, Kulkarni D, Kochut A, Pezoldt J, Pisano F, Pils MC, Genth H, Huehn J, Dersch P. The cytotoxic necrotizing factor of Yersinia pseudotuberculosis (CNFY) enhances inflammation and Yop delivery during infection by activation of Rho GTPases. PLoS Pathog 2013; 9:e1003746. [PMID: 24244167 PMCID: PMC3820761 DOI: 10.1371/journal.ppat.1003746] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 09/20/2013] [Indexed: 12/19/2022] Open
Abstract
Some isolates of Yersinia pseudotuberculosis produce the cytotoxic necrotizing factor (CNFY), but the functional consequences of this toxin for host-pathogen interactions during the infection are unknown. In the present study we show that CNFY has a strong influence on virulence. We demonstrate that the CNFY toxin is thermo-regulated and highly expressed in all colonized lymphatic tissues and organs of orally infected mice. Most strikingly, we found that a cnfY knock-out variant of a naturally toxin-expressing Y. pseudotuberculosis isolate is strongly impaired in its ability to disseminate into the mesenteric lymph nodes, liver and spleen, and has fully lost its lethality. The CNFY toxin contributes significantly to the induction of acute inflammatory responses and to the formation of necrotic areas in infected tissues. The analysis of the host immune response demonstrated that presence of CNFY leads to a strong reduction of professional phagocytes and natural killer cells in particular in the spleen, whereas loss of the toxin allows efficient tissue infiltration of these immune cells and rapid killing of the pathogen. Addition of purified CNFY triggers formation of actin-rich membrane ruffles and filopodia, which correlates with the activation of the Rho GTPases, RhoA, Rac1 and Cdc42. The analysis of type III effector delivery into epithelial and immune cells in vitro and during the course of the infection further demonstrated that CNFY enhances the Yop translocation process and supports a role for the toxin in the suppression of the antibacterial host response. In summary, we highlight the importance of CNFY for pathogenicity by showing that this toxin modulates inflammatory responses, protects the bacteria from attacks of innate immune effectors and enhances the severity of a Yersinia infection. Various toxins and effector proteins of bacterial pathogens have been found to manipulate eukaryotic cell machineries to promote persistence and proliferation within their hosts. Many of these virulence factors target small Rho GTPases, but their role in pathogenesis is often unknown. Here, we addressed the expression and functional consequences of the CNFY toxin found in some isolates of Y. pseudotuberculosis. We found that CNFY besides modulating the cell cytoskeleton by activation of the GTPases RhoA, Rac1 and Cdc42, contributes to increased inflammation and tissue damage. Moreover, CNFY increases the ability of Yersinia to prevent the attack of the immune system, by enhancing the delivery of antiphagocytic and cytotoxic effectors into professional phagocytes. Our findings provide the first insights into the multi-functional action and severe consequences of the CNFY toxin on the inflammatory response and disease-associated tissue damage during the natural course of the infection.
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Affiliation(s)
- Janina Schweer
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Devesha Kulkarni
- Department of Experimental Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Annika Kochut
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Joern Pezoldt
- Department of Experimental Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Fabio Pisano
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Marina C. Pils
- Mouse Pathology, Animal Experimental Unit, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Harald Genth
- Institute for Toxicology, Medical School Hannover, Hannover, Germany
| | - Jochen Huehn
- Department of Experimental Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- * E-mail:
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18
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Wolters M, Boyle EC, Lardong K, Trülzsch K, Steffen A, Rottner K, Ruckdeschel K, Aepfelbacher M. Cytotoxic necrotizing factor-Y boosts Yersinia effector translocation by activating Rac protein. J Biol Chem 2013; 288:23543-53. [PMID: 23803609 DOI: 10.1074/jbc.m112.448662] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Pathogenic Yersinia spp. translocate the effectors YopT, YopE, and YopO/YpkA into target cells to inactivate Rho family GTP-binding proteins and block immune responses. Some Yersinia spp. also secrete the Rho protein activator cytotoxic necrotizing factor-Y (CNF-Y), but it has been unclear how the bacteria may benefit from Rho protein activation. We show here that CNF-Y increases Yop translocation in Yersinia enterocolitica-infected cells up to 5-fold. CNF-Y strongly activated RhoA and also delayed in time Rac1 and Cdc42, but when individually expressed, constitutively active mutants of Rac1, but not of RhoA, increased Yop translocation. Consistently, knock-out or knockdown of Rac1 but not of RhoA, -B, or -C inhibited Yersinia effector translocation in CNF-Y-treated and control cells. Activation or knockdown of Cdc42 also affected Yop translocation but much less efficiently than Rac. The increase in Yop translocation induced by CNF-Y was essentially independent of the presence of YopE, YopT, or YopO in the infecting Yersinia strain, indicating that none of the Yops reported to inhibit translocation could reverse the CNF-Y effect. In summary, the CNF-Y activity of Yersinia strongly enhances Yop translocation through activation of Rac.
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Affiliation(s)
- Manuel Wolters
- Institute for Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
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19
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Timchenko N, Adgamov R, Ermolaeva S. Variability in the functional domains of the rho-modifying toxins of Yersinia pseudotuberculosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 954:261-6. [PMID: 22782772 DOI: 10.1007/978-1-4614-3561-7_33] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Nelly Timchenko
- Institute of Epidemiology and Microbiology, Russian Academy of Medical Sciences Siberian Branch, Vladivostok, Russia.
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20
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21
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Mou S, Cote CK, Worsham PL. Cytotoxic necrotizing factor is an effective immunogen in a Yersinia pseudotuberculosis aerosol mouse model. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 954:179-81. [PMID: 22782762 DOI: 10.1007/978-1-4614-3561-7_23] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Sherry Mou
- Bacteriology Division, US Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD, USA
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22
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Pasteurella multocida toxin interaction with host cells: entry and cellular effects. Curr Top Microbiol Immunol 2012; 361:93-111. [PMID: 22552700 PMCID: PMC4408768 DOI: 10.1007/82_2012_219] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The mitogenic dermonecrotic toxin from Pasteurella multocida (PMT) is a 1285-residue multipartite protein that belongs to the A-B family of bacterial protein toxins. Through its G-protein-deamidating activity on the α subunits of heterotrimeric G(q)-, G(i)- and G(12/13)-proteins, PMT potently stimulates downstream mitogenic, calcium, and cytoskeletal signaling pathways. These activities lead to pleiotropic effects in different cell types, which ultimately result in cellular proliferation, while inhibiting cellular differentiation, and account for the myriad of physiological outcomes observed during infection with toxinogenic strains of P. multocida.
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23
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Yu H, Kim KS. YgfZ contributes to secretion of cytotoxic necrotizing factor 1 into outer-membrane vesicles in Escherichia coli. MICROBIOLOGY-SGM 2011; 158:612-621. [PMID: 22174383 DOI: 10.1099/mic.0.054122-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cytotoxic necrotizing factor 1 (CNF1), a Rho GTPase-activating bacterial toxin, has been shown to contribute to invasion by meningitis-causing Escherichia coli K1 of human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier. However, CNF1 is a cytosolic protein and it remains unclear how its secretion occurs, contributing to E. coli invasion of HBMEC. To investigate the genetic requirement for CNF1 secretion in E. coli K1 strain RS218, we performed mini-Tn5 in vitro mutagenesis and constructed a transposon mutant library of strain NBC, in which β-lactamase was fused to the C-terminus of CNF1 in the chromosome of strain RS218. We identified a transposon mutant (NBC-1E6) that exhibited reduced β-lactamase activity in its culture supernatant and had the transposon inserted into the ygfZ gene. When ygfZ was deleted from the genome of strain RS218 (ΔygfZ), the translocation of CNF1 into HBMEC was impaired. Subcellular localization analysis of CNF1 demonstrated that YgfZ, a periplasmic protein, contributes to secretion of CNF1 into outer-membrane vesicles (OMVs). The ΔygfZ mutant was significantly defective in invasion of HBMEC compared to the parent E. coli K1 strain. The defects of the ΔygfZ mutant in CNF1 secretion into OMVs and translocation into HBMEC as well as invasion of HBMEC were abrogated by complementation with ygfZ. Taken together, our findings demonstrate that YgfZ contributes to CNF1 secretion into OMVs in meningitis-causing E. coli K1.
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Affiliation(s)
- Hao Yu
- Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, 200 North Wolfe Street, Room 3157, Baltimore, MD 21287, USA
| | - Kwang Sik Kim
- Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, 200 North Wolfe Street, Room 3157, Baltimore, MD 21287, USA
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Brothers MC, Ho M, Maharjan R, Clemons NC, Bannai Y, Waites MA, Faulkner MJ, Kuhlenschmidt TB, Kuhlenschmidt MS, Blanke SR, Rienstra CM, Wilson BA. Membrane interaction of Pasteurella multocida toxin involves sphingomyelin. FEBS J 2011; 278:4633-48. [PMID: 21951695 PMCID: PMC3220749 DOI: 10.1111/j.1742-4658.2011.08365.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pasteurella multocida toxin (PMT) is an AB toxin that causes pleiotropic effects in targeted host cells. The N-terminus of PMT (PMT-N) is considered to harbor the membrane receptor binding and translocation domains responsible for mediating cellular entry and delivery of the C-terminal catalytic domain into the host cytosol. Previous studies have implicated gangliosides as the host receptors for PMT binding. To gain further insight into the binding interactions involved in PMT binding to cell membranes, we explored the role of various membrane components in PMT binding, utilizing four different approaches: (a) TLC-overlay binding experiments with (125) I-labeled PMT, PMT-N or the C-terminus of PMT; (b) pull-down experiments using reconstituted membrane liposomes with full-length PMT; (c) surface plasmon resonance analysis of PMT-N binding to reconstituted membrane liposomes; (d) and surface plasmon resonance analysis of PMT-N binding to HEK-293T cell membranes without or with sphingomyelinase, phospholipase D or trypsin treatment. The results obtained revealed that, in our experimental system, full-length PMT and PMT-N did not bind to gangliosides, including monoasialogangliosides GM(1) , GM(2) or GM(3) , but instead bound to membrane phospholipids, primarily the abundant sphingophospholipid sphingomyelin or phosphatidylcholine with other lipid components. Collectively, these studies demonstrate the importance of sphingomyelin for PMT binding to membranes and suggest the involvement of a protein co-receptor.
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Affiliation(s)
| | - Mengfei Ho
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
- Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, USA
| | - Ram Maharjan
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
| | - Nathan C. Clemons
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
| | - Yuka Bannai
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
| | - Mark A. Waites
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
| | | | | | | | - Steven R. Blanke
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
- Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, USA
| | - Chad M. Rienstra
- Department of Chemistry, University of Illinois, Urbana, IL 61801, USA
- Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA
| | - Brenda A. Wilson
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
- Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, USA
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Abstract
Many bacterial pathogens produce protein toxins to outmanoeuvre the immune system of the host. Some of these proteins target regulatory GTPases such as those belonging to the RHO family, which control the actin cytoskeleton of the host cell. In this Review, I discuss a diversity of mechanisms that are used by bacterial effectors and toxins to modulate the activity of host GTPases, with a focus on covalent modifications such as ADP-ribosylation, glucosylation, adenylylation, proteolysis, deamidation and transglutamination.
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Affiliation(s)
- Klaus Aktories
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, 79104 Freiburg, Germany.
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26
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Samba-Louaka A, Taieb F, Nougayrède JP, Oswald E. Cif type III effector protein: a smart hijacker of the host cell cycle. Future Microbiol 2009; 4:867-77. [PMID: 19722840 DOI: 10.2217/fmb.09.60] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
During coevolution with their hosts, bacteria have developed functions that allow them to interfere with the mechanisms controlling the proliferation of eukaryotic cells. Cycle inhibiting factor (Cif) is one of these cyclomodulins, the family of bacterial effectors that interfere with the host cell cycle. Acquired early during evolution by bacteria isolated from vertebrates and invertebrates, Cif is an effector protein of type III secretion machineries. Cif blocks the host cell cycle in G1 and G2 by inducing the accumulation of the cyclin-dependent kinase inhibitors p21(waf1/cip1) and p27(kip1). The x-ray crystal structure of Cif reveals it to be a divergent member of a superfamily of enzymes including cysteine proteases and acetyltransferases. This review summarizes and discusses what we know about Cif, from the bacterial gene to the host target.
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27
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Cleavage of Escherichia coli cytotoxic necrotizing factor 1 is required for full biologic activity. Infect Immun 2009; 77:1835-41. [PMID: 19237521 DOI: 10.1128/iai.01145-08] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cytotoxic necrotizing factor 1 (CNF1) is a protein toxin produced by pathogenic Escherichia coli strains. CNF1 constitutively activates small GTPases of the Rho family by deamidation of a glutamine, which is crucial for GTP hydrolysis. The toxin is taken up into mammalian cells by receptor-mediated endocytosis and is delivered from late endosomes into the cytosol. Here, we show that an approximately 55-kDa fragment of CNF1, which contains the catalytic domain and an additional part of the toxin, is present in the cytosol. The processing of this fragment requires an acidic pH and insertion of the toxin into the endosomal membrane. We define the cleavage site region as the region located between amino acids 532 and 544 of CNF1. The data provide insight into the complex mechanism of uptake of bacterial toxins into mammalian cells.
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28
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Cytotoxic necrotizing factor type 1-neutralizing monoclonal antibody NG8 recognizes three amino acids in a C-terminal region of the toxin and reduces toxin binding to HEp-2 cells. Infect Immun 2008; 77:170-9. [PMID: 18955470 DOI: 10.1128/iai.00943-08] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Cytotoxic necrotizing factor type 1 (CNF1) and CNF2 are toxins of pathogenic Escherichia coli that share 85% identity over 1,014 amino acids. Although both of these toxins modify GTPases, CNF1 is a more potent inducer of multinucleation in HEp-2 cells, binds more efficiently to HEp-2 cells, and, despite the conservation of amino acids (C866 and H881) required for enzymatic activity of the toxins, deamidates RhoA and Cdc42 better than CNF2. Here we exploited the differences between CNF1 and CNF2 to define the epitope on CNF1 to which the CNF1-specific neutralizing monoclonal antibody (MAb) (MAb NG8) binds and to determine the mechanism by which MAb NG8 neutralizes CNF1 activity on HEp-2 cells. For these purposes, we generated a panel of 21 site-directed mutants in which amino acids in CNF1 were exchanged for the amino acids in CNF2 between amino acids 546 and 869 and vice versa. This region of CNF1 not only is recognized by MAb NG8 but also is involved in binding of this toxin to HEp-2 cells. All the mutants retained the capacity to induce multinucleation of HEp-2 cells. However, the CNF1 double mutant with D591E and F593L mutations (CNF1(D591E F593L)) and the CNF1(H661Q) single mutant displayed drastically reduced reactivity with MAb NG8. A reverse chimeric triple mutant, CNF1(E591D L593F Q661H), imparted MAb NG8 reactivity to CNF2. MAb NG8 neutralized CNF2(E591D L593F Q661H) activity in a dose-dependent manner and reduced the binding of this chimeric toxin to HEp-2 cells. Taken together, these results pinpoint three amino acids in CNF1 that are key amino acids for recognition by neutralizing MAb NG8 and further help define a region in CNF1 that is critical for full toxin binding to HEp-2 cells.
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Lemonnier M, Landraud L, Lemichez E. Rho GTPase-activating bacterial toxins: from bacterial virulence regulation to eukaryotic cell biology. FEMS Microbiol Rev 2007; 31:515-34. [PMID: 17680807 DOI: 10.1111/j.1574-6976.2007.00078.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Studies on the interactions of bacterial pathogens with their host have provided an invaluable source of information on the major functions of eukaryotic and prokaryotic cell biology. In addition, this expanding field of research, known as cellular microbiology, has revealed fascinating examples of trans-kingdom functional interplay. Bacterial factors actually exploit eukaryotic cell machineries using refined molecular strategies to promote invasion and proliferation within their host. Here, we review a family of bacterial toxins that modulate their activity in eukaryotic cells by activating Rho GTPases and exploiting the ubiquitin/proteasome machineries. This family, found in human and animal pathogenic Gram-negative bacteria, encompasses the cytotoxic necrotizing factors (CNFs) from Escherichia coli and Yersinia species as well as dermonecrotic toxins from Bordetella species. We survey the genetics, biochemistry, molecular and cellular biology of these bacterial factors from the standpoint of the CNF1 toxin, the paradigm of Rho GTPase-activating toxins produced by urinary tract infections causing pathogenic Escherichia coli. Because it reveals important connections between bacterial invasion and the host inflammatory response, the mode of action of CNF1 and its related Rho GTPase-targetting toxins addresses major issues of basic and medical research and constitutes a privileged experimental model for host-pathogen interaction.
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Affiliation(s)
- Marc Lemonnier
- INSERM U627, UNSA, Faculté de Médecine, 28 Avenue de Valombrose, 06107 Nice cedex 2, France.
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KADHUM H, FINLAY D, ROWE M, WILSON I, BALL H. Occurrence and characteristics of cytotoxic necrotizing factors, cytolethal distending toxins and other virulence factors in Escherichia coli from human blood and faecal samples. Epidemiol Infect 2007; 136:752-60. [PMID: 17678557 PMCID: PMC2870871 DOI: 10.1017/s0950268807009247] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Escherichia coli isolates from human blood (n=266) and faecal (n=237) samples were examined for cytotoxic necrotizing factors 1 and 2 (CNF 1 and 2), cytolethal distending toxin (CDT), and putative virulence factors that have been associated with disease conditions in humans and animals. PCR showed that the chromosomally encoded, Rho-activating, CNF1 (68/544, 12.5%) was more common than the transmissible plasmid-borne CNF2 (3/544, 0.6%). The relative risk of having either CNF or CDT toxin genes in blood compared to faecal isolates was 3.88 (95% CI 2.36-6.38). This was highly significant (P<0.0001) and demonstrates the importance of these factors in bloodstream infections. Fifty-one of 65 (78%) E. coli bearing CNF1 and 11 of 21 (52%) of E. coli bearing CDT also carried the pyelonephritis-associated pilus gene, papG. The S fimbrial adhesin gene, sfa, was found in 57 blood (21%) and eight faecal samples (3%). The F17 fimbrial adhesin gene and afimbrial adhesin gene afa did not occur frequently. Haemolysin (hly) was found in all of the isolates tested. Further studies must be designed to identify the clinical significance of these genes and their role in pathogenesis.
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Affiliation(s)
- H. J. KADHUM
- Department of Food Science (Food Microbiology), The Queen's University of Belfast, Newforge Lane, Belfast, UK
| | - D. FINLAY
- Agri-Food and Biosciences Institute (AFBI) Veterinary Science Division, Belfast, UK
| | - M. T. ROWE
- Department of Food Science (Food Microbiology), The Queen's University of Belfast, Newforge Lane, Belfast, UK
- Agriculture, Food and Environmental Science Division (Food Microbiology Branch), Belfast, UK
- Author for correspondence: Dr M. T. Rowe, Agriculture, Food and Environmental Science Division (Food Microbiology Branch), Newforge Lane, Belfast BT9 5PX, UK. ()
| | - I. G. WILSON
- Northern Ireland Public Health Laboratory, Belfast City Hospital, Belfast, UK
| | - H. J. BALL
- Agri-Food and Biosciences Institute (AFBI) Veterinary Science Division, Belfast, UK
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Blumenthal B, Hoffmann C, Aktories K, Backert S, Schmidt G. The cytotoxic necrotizing factors from Yersinia pseudotuberculosis and from Escherichia coli bind to different cellular receptors but take the same route to the cytosol. Infect Immun 2007; 75:3344-53. [PMID: 17438028 PMCID: PMC1932955 DOI: 10.1128/iai.01937-06] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2006] [Revised: 01/31/2007] [Accepted: 04/05/2007] [Indexed: 11/20/2022] Open
Abstract
The cytotoxic necrotizing factors CNF1 and CNF2 produced by pathogenic Escherichia coli strains and CNF(Y) of Yersinia pseudotuberculosis constitutively activate small GTPases of the Rho family. They deamidate a glutamine (Gln63 in RhoA), which is crucial for GTP hydrolysis. CNF1 and CNF(Y) exhibit 61% identity on the amino acid level, with equal distribution over the whole molecule. Although the two toxins are homologous in the receptor binding domain, we show that they bind to different cellular receptors. CNF(Y) does not enter Caco-2 and CHO-K1 cells, which are responsive to CNF1. In contrast, HeLa, Hep-2, and HEK 293 cells do respond to both toxins. Competition studies with catalytically inactive mutants of the toxins revealed that binding of CNF1 has no influence on the uptake of CNF(Y) into HeLa cells. In contrast, uptake of CNF1 is retarded after preincubation of HeLa cells with the catalytically inactive mutant of CNF(Y), suggesting that the toxin receptors overlap. Moreover, we compared the pathways of the toxins from receptor binding into the cytosol and showed that both toxins are taken up independent of the presence of clathrin or lipid rafts and are released into the cytosol from acidified endosomes.
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Affiliation(s)
- Britta Blumenthal
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität Freiburg, Albert-Strasse 25, 79104 Freiburg, Germany
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Hoffmann C, Aktories K, Schmidt G. Change in Substrate Specificity of Cytotoxic Necrotizing Factor Unmasks Proteasome-independent Down-regulation of Constitutively Active RhoA. J Biol Chem 2007; 282:10826-32. [PMID: 17296609 DOI: 10.1074/jbc.m610451200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Cytotoxic necrotizing factors CNF1 and CNF2 are produced by pathogenic Escherichia coli strains. They constitutively activate small GTPases of the Rho family by deamidation of a glutamine, which is crucial for GTP hydrolysis. Recently, a novel CNF (CNF(Y)) encompassing 65% identity to CNF1 has been identified in Yersinia pseudotuberculosis. In contrast to the E. coli toxins, which activate several isoforms of Rho family GTPases, CNF(Y) is a strong and selective activator of RhoA in vivo. By constructing chimeras between CNF1 and CNF(Y), we show that this substrate specificity is based on differences in the catalytic domains, whereas the receptor binding and translocation domains have no influence. We further define a loop element (L8) on the surface of the catalytic domains as important for substrate recognition. A single amino acid exchange in L8 is sufficient to shift substrate specificity of CNF1. Moreover, it is shown that RhoA activation by CNF1 is transient, which may be the consequence of the broader substrate specificity of the E. coli toxin, leading to cross-talk between the activated GTPases.
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Affiliation(s)
- Claudia Hoffmann
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie der Albert-Ludwigs-Universität Freiburg, Albert-Strasse 25, 79104 Freiburg, Germany
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Kouokam JC, Wai SN, Fällman M, Dobrindt U, Hacker J, Uhlin BE. Active cytotoxic necrotizing factor 1 associated with outer membrane vesicles from uropathogenic Escherichia coli. Infect Immun 2006; 74:2022-30. [PMID: 16552031 PMCID: PMC1418910 DOI: 10.1128/iai.74.4.2022-2030.2006] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cytotoxic necrotizing factor type 1 (CNF1) is one of the virulence factors produced by uropathogenic Escherichia coli (UPEC). How this toxin is translocated from the bacterial cytoplasm to the surrounding environment is not well understood. Our data suggest that CNF1 may be regarded as a secreted protein, since it could be detected in culture supernatants. Furthermore, we found that CNF1 was tightly associated to outer membrane vesicles, suggesting that such vesicles play a role in the secretion of this protein. Interestingly, vesicle samples containing CNF1 could exert the effects known for this protein on HeLa cell cultures, showing that CNF1 is transported by vesicles in its active form. Taken together, our results strongly suggest that outer membrane vesicles could be a means for the bacteria to deliver CNF1 to the environment and to the infected tissue. In addition, our results indicate that the histone-like nucleoid structuring protein H-NS has a role in the downregulation of CNF1 production and that it affects the outer membrane vesicle release in UPEC strain J96.
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Affiliation(s)
- J Clavin Kouokam
- Department of Molecular Biology, Umeå University, S-901 87 Umeå, Sweden
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Abstract
The CNF1 toxin is produced by some uropathogenic (UPECs) andmeningitis-causing Escherichia coli strains. It belongs to a large family of bacterial virulence factors and toxins modifying cellular regulators of the actin cytoskeleton, namely the Rho GTPases. CNF1 autonomously enters the host cell cytosol, where it catalyzes the constitutive activation of Rho GTPases by deamidation. This activation is, however, attenuated because of activated Rho protein ubiquitin-mediated proteasomal degradation. Both Rho protein activation and deactivation confer phagocytic properties on epithelial and endothelial cells, as well as epithelial cell motility and cell-cell junction dynamics. Transcriptome analysis using DNA microarray revealed that endothelial cells respond to high doses of CNF1 by launching a genetic program of host alarm. This host cell reaction to CNF1 intoxication also indicates that degradation of activated Rho proteins by the proteasome may lead to a lowering of the threshold of the intoxicated cell inflammatory response. These results are consistent with growing evidence that Rho proteins control the cell inflammatory responses. It is tempting to assume that Rho deregulation may participate in various immunological disorders also involved in cancer.
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Affiliation(s)
- P Munro
- Faculté de Médecine, 1/INSERM, U627, 28 Avenue de Valombrose, 06107 Nice, France
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35
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Abstract
Many bacterial cytotoxins act on eukaryotic cells by targeting the regulators that are involved in controlling the cytoskeleton or by directly modifying actin, with members of the Rho GTPase family being particularly important targets. The actin cytoskeleton, and especially the GTPase 'molecular switches' that are involved in its control, have crucial functions in innate and adaptive immunity, and have pivotal roles in the biology of infection. In this review, we briefly discuss the role of the actin cytoskeleton and the Rho GTPases in host-pathogen interactions, and review the mode of actions of bacterial protein toxins that target these components.
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Affiliation(s)
- Klaus Aktories
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie der Albert-Ludwigs-Universität, Otto-Krayer-Haus, Albert-Strasse 25, D-79104 Freiburg, Germany.
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36
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Munro P, Flatau G, Anjuère F, Hofman V, Czerkinsky C, Lemichez E. The Rho GTPase activators CNF1 and DNT bacterial toxins have mucosal adjuvant properties. Vaccine 2005; 23:2551-6. [PMID: 15780436 DOI: 10.1016/j.vaccine.2004.11.042] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2004] [Revised: 10/12/2004] [Accepted: 11/11/2004] [Indexed: 10/26/2022]
Abstract
Cytotoxic necrotizing factor 1 (CNF1) from uropathogenic Escherichia coli belongs to a family of factors activating Rho GTPases. We report the in vivo effects of CNF1 in mice co-fed toxin and the soluble protein antigen ovalbumin (OVA). Similar to cholera toxin, CNF1 elicits adjuvanticity anti-OVA responses, both systemic and mucosal. In contrast, the catalytic inactive mutant CNF1-C866S demonstrated no effects. Using dermonecrotic toxin (DNT), a closely related Rho activating toxin from Bordetella, we discovered that the adjuvant property is within the DNT catalytic domain. Manipulation of Rho proteins thus provides a possible new approach for the development of effective mucosal immunoadjuvants.
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Affiliation(s)
- Patrick Munro
- INSERM, U627, Faculté de Médecine, 28 Avenue de Valombrose, F-06107 Nice Cedex 2, France
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37
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Fällman M, Gustavsson A. Cellular mechanisms of bacterial internalization counteracted by Yersinia. INTERNATIONAL REVIEW OF CYTOLOGY 2005; 246:135-88. [PMID: 16164968 DOI: 10.1016/s0074-7696(05)46004-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Upon host-cell contact, human pathogenic Yersinia species inject Yop virulence effectors into the host through a Type III secretion-and-translocation system. These virulence effectors cause a block in phagocytosis (YopE, YopT, YpkA, and YopH) and suppression of inflammatory mediators (YopJ). The Yops that block phagocytosis either interfere with the host cell actin regulation of Rho GTPases (YopE, YopT, and YpkA) or specifically and rapidly inactivate host proteins involved in signaling from the receptor to actin (YopH). The block in uptake has been shown to be activated following binding to Fc, Complement, and beta1-integrin receptors in virtually any kind of host cell. Thus, the use of Yersinia as a model system to study Yersinia-host cell interactions provides a good tool to explore signaling pathways involved in phagocytosis.
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Affiliation(s)
- Maria Fällman
- Department of Molecular Biology, Umeå University, SE-90187 Umeå, Sweden
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38
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Marini RP, Taylor NS, Liang AY, Knox KA, Peña JA, Schauer DB, Fox JG. Characterization of hemolytic Escherichia coli strains in ferrets: recognition of candidate virulence factor CNF1. J Clin Microbiol 2004; 42:5904-8. [PMID: 15583337 PMCID: PMC535218 DOI: 10.1128/jcm.42.12.5904-5908.2004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2004] [Revised: 05/06/2004] [Accepted: 07/31/2004] [Indexed: 11/20/2022] Open
Abstract
Diseases associated with Escherichia coli infection are the subject of renewed interest due to emerging conditions such as hemolytic uremia syndrome. A collection of 15 strains of beta-hemolytic E. coli was isolated from diarrheic feces and diseased tissues of ferrets. All 15 strains were positive in specific PCR assays for the presence of hlyA, pap1, and cnf1. Seven of the cnf1-positive isolates were tested and shown to have a cytopathic effect on HeLa cell monolayers. The pathogenesis of these strains warrants future study.
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Affiliation(s)
- Robert P Marini
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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39
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Cytotoxic Necrotizing Factors: Rho-Activating Toxins from Escherichia coli. EcoSal Plus 2004; 1. [PMID: 26443355 DOI: 10.1128/ecosalplus.8.7.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This article reviews the Escherichia coli toxins called cytotoxic necrotizing factors (CNFs), which cause activation of Rho GTPases. It describes their modes of action, structure-function relationships, and roles in disease. Rho GTPases, the targets of CNFs, belong to the Ras superfamily of low molecular mass GTPases and act as molecular switches in various signaling pathways. Low molecular mass GTPases of the Rho family are known as master regulators of the actin cytoskeleton. Moreover, they are involved in various signal transduction processes, from transcriptional activation, cell cycle progression, and cell transformation to apoptosis. CNFs are cytotoxic for a wide variety of cells, including 3T3 fibroblasts, Chinese hamster ovary cells, Vero cells, HeLa cells, and cell lines of neuronal origin. This implies that a commonly expressed receptor is responsible for the uptake of CNF1. Cultured mammalian cells treated with CNFs are characterized by dramatic changes in actin-containing structures, including stress fibers, lamellipodia, and filopodia. Most striking is the formation of multinucleation in these cells. Rho GTPases are increasingly recognized as essential factors in the development of cancer and metastasis. This fact has initiated a discussion as to whether activation of Rho proteins by CNFs might be involved in tumorigenesis. Moreover, CNF1 increases the expression of the cyclooxygenase 2 (Cox2) gene in fibroblasts. Increased expression of Cox2 is observed in some types of tumors, e.g., colon carcinoma. Lipid-mediators produced by the enzyme are suggested to be responsible for tumor progression.
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40
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Aepfelbacher M. Modulation of Rho GTPases by type III secretion system translocated effectors of Yersinia. Rev Physiol Biochem Pharmacol 2004; 152:65-77. [PMID: 15378389 DOI: 10.1007/s10254-004-0035-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Pathogenic species of the bacterial genus Yersinia subdue the immune system to proliferate and spread within the host organism. For this purpose yersiniae employ a type III secretion apparatus which governs injection of six effector proteins ( Y ersinia outer proteins; Yops) into host cells. Yops control various regulatory and signalling proteins in a unique and highly specific manner. YopE, YopT, and YpkA/YopO modulate the activity of Rho GTP-binding proteins, whereas YopH dephosphorylates phospho-tyrosine residues in focal adhesion proteins. Furthermore, YopP/YopJ and YopM affect cell survival/apoptosis and cell proliferation, respectively. In this review the focus will be on the biochemistry and cellular effects of YopT, YopE, YopO/YpkA, and YopH.
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Affiliation(s)
- M Aepfelbacher
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Pettenkoferstr. 9a, 80336, München, Germany.
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41
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Landraud L, Pulcini C, Gounon P, Flatau G, Boquet P, Lemichez E. E. coli CNF1 toxin: a two-in-one system for host-cell invasion. Int J Med Microbiol 2004; 293:513-8. [PMID: 15149026 DOI: 10.1078/1438-4221-00295] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The cytotoxic necrotizing factor-1 (CNF1), a bacterial toxin of uropathogenic bacteria (UPEC), hijacks cellular Rho proteins of the Ras GTPase super-family. Recently, we have made three important findings. First, we have established that, following Rho protein activation by deamidation, these cellular proteins are ubiquitylated and degraded by the proteasome. Second, the low level of activated Rho proteins which results from the dual molecular mechanism of action of CNF1 (Rho protein activation followed by their degradation), confers high invasive properties to UPECs. Finally, we have reported that ubiquitylation and degradation of Rac is lost in HEp-2 carcinoma cells, thereby suggesting a possible link between Rho protein ubiquitylation and tumor progression.
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Affiliation(s)
- Luce Landraud
- INSERM U452, Faculté de Médecine de Nice, Nice, France
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42
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Abstract
The actin cytoskeleton of mammalian cells is involved in many processes that affect the growth and colonization of bacteria, such as migration of immune cells, phagocytosis by macrophages, secretion of cytokines, maintenance of epithelial barrier functions and others. With respect to these functions, it is not surprising that many bacterial protein toxins, which are important virulence factors and causative agents of human and/or animal diseases, target the actin cytoskeleton of the host. Some toxins target actin directly, such as the C2 toxin produced by Clostridium botulinum. Moreover, bacterial toxins target the cytoskeleton indirectly by modifying actin regulators such as the low-molecular-mass guanosine triphosphate (GTP)-binding proteins of the Rho family. Remarkably, toxins affect these GTPases in a bidirectional manner. Some toxins inhibit and some activate the GTPases. Here we review the Rho-activating toxins CNF1 and CNF2 (cytotoxic necrotizing factors) from Escherichia coli, the Yersinia CNF(Y) and the dermonecrotic toxin (DNT) from Bordetella species. We describe and compare their uptake into mammalian cells, mode of action, structure-function relationship, substrate specificity and role in diseases.
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Affiliation(s)
- C Hoffmann
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie der Albert-Ludwigs-Universität Freiburg, Albert-Str. 25, 79104, Freiburg, Germany
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Horne SM, Goplin JL, Giddings CW, Dyer NW, Nolan LK. Cloning and sequencing of cnf1 from Escherichia coli incriminated in mink and bovine colibacillosis. Vet Res Commun 2004; 28:103-12. [PMID: 14992240 DOI: 10.1023/b:verc.0000012109.68007.1e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Colibacillosis is responsible for significant losses to the mink and cattle industries. Previous work in our laboratory and by others has suggested that possession of cnf1, the gene encoding cytotoxic necrotizing factor (CNF1), may contribute to the virulence of isolates of E. coli from mink and cattle. The cnf1 gene from E. coli isolated from a mink with colisepticaemia and a bovid with scours was amplified and cloned as a 3.5 kb fragment, and the fragment was sequenced. The cnf1 sequences from the mink and bovine isolates of E. coli were compared to each other and to cnf1 sequences of E. coli from urinary tract and diarrhoea-associated infections of humans. The difference was only 7 nucleotides between the cnf1 sequences of the mink and bovine isolates of E. coli, which translated into 7 differences in amino acids. The cnf1 sequence of the mink isolate of E. coli had 15 nucleotide differences from the cnf1 sequences of the human isolate of E. coli (GenBank X70670), which translated into 11 differences in amino acids between these proteins. The cnf1 sequence of the bovine isolate of E. coli had 14 nucleotide differences from the cnf1 sequence of the human isolate of E. coli (GenBank X70670), which translated into 10 differences in amino acids between these proteins. The highly conserved sequences of the amino acids of CNF1 proteins make them a promising target for detection and control of the CNF1-producing E. coli involved in disease among various host species.
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Affiliation(s)
- S M Horne
- Department of Veterinary and Microbiological Sciences, North Dakota State University, Fargo, ND 58105, USA
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44
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Hoffmann C, Pop M, Leemhuis J, Schirmer J, Aktories K, Schmidt G. The Yersinia pseudotuberculosis Cytotoxic Necrotizing Factor (CNFY) Selectively Activates RhoA. J Biol Chem 2004; 279:16026-32. [PMID: 14761941 DOI: 10.1074/jbc.m313556200] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The cytotoxic necrotizing factors (CNF)1 and CNF2 from pathogenic Escherichia coli strains activate RhoA, Rac1, and Cdc42 by deamidation of Gln63 (RhoA) or Gln61 (Rac and Cdc42). Recently, a novel cytotoxic necrotizing factor termed CNFY was identified in Yersinia pseudotuberculosis strains (Lockman, H. A., Gillespie, R. A., Baker, B. D., and Shakhnovich, E. (2002) Infect. Immun. 70, 2708-2714). We amplified the cnfy gene from genomic DNA of Y. pseudotuberculosis, cloned and expressed the recombinant protein, and studied its activity. Recombinant GST-CNFY induced morphological changes in HeLa cells and caused an upward shift of RhoA in SDS-PAGE, as is known for GST-CNF1 and GST-CNF2. Mass spectrometric analysis of GST-CNFY-treated RhoA confirmed deamidation at Glu63. Treatment of RhoA, Rac1, and Cdc42 with GST-CNFY decreased their GTPase activities, indicating that all of these Rho proteins could serve as substrates for GST-CNFY in vitro. In contrast, RhoA, but not Rac or Cdc42, was the substrate of GST-CNFY in culture cells. GST-CNFY caused marked stress fiber formation in HeLa cells after 2 h. In contrast to GST-CNF1, formation of filopodia or lamellipodia was not induced with GST-CNFY. Accordingly, effector pull-down experiments with lysates of toxin-treated cells revealed strong activation of RhoA but no activation of Rac1 or Cdc42 after 6 h of GST-CNFY-treatment. Moreover, in rat hippocampal neurons, GST-CNFY results in the retraction of neurites, indicating RhoA activation. In contrast, no activation of Rac or Cdc42 was found. Altogether, our data suggest that CNFY from Y. pseudotuberculosis is a strong, selective activator of RhoA, which can be used as a powerful tool for constitutive RhoA activation without concomitant activation of Rac1 or Cdc42.
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Affiliation(s)
- Claudia Hoffmann
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie der Albert-Ludwigs-Universität Freiburg, D-79104 Freiburg, Germany
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Golubov A, Heesemann J, Rakin A. Uncovering genomic differences in human pathogenic Yersinia enterocolitica. FEMS IMMUNOLOGY AND MEDICAL MICROBIOLOGY 2003; 38:107-11. [PMID: 13129644 DOI: 10.1016/s0928-8244(03)00182-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
To map out genomic differences between highly pathogenic Yersinia enterocolitica WA-314C biogroup 1B, serotype O:8 strain and low-pathogenic Y. enterocolitica Y-108C biogroup 4, serotype O:3 strain we have applied a method of suppression subtractive hybridization (SSH). In total, 428 WA-314-specific and 83 Y-108-specific sequences were uncovered by SSH. Among them were DNA fragments with similarity to known genes from several groups: (1) genes involved in O-antigen biosynthesis, (2) host-specific restriction-modification systems, (3) systems of iron and heme acquisition and storage, (4) flagellar biogenesis genes, (5) putative virulence factors, (6) drug resistance genes, and (7) mobile elements. Mapped out genomic differences may be applied in identification and development of novel therapeutic strategies for the treatment of enteropathogenic Yersinia.
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Affiliation(s)
- Andrey Golubov
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Pettenkofer Str. 9a, 80336 Munich, Germany
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Hinchliffe SJ, Isherwood KE, Stabler RA, Prentice MB, Rakin A, Nichols RA, Oyston PCF, Hinds J, Titball RW, Wren BW. Application of DNA microarrays to study the evolutionary genomics of Yersinia pestis and Yersinia pseudotuberculosis. Genome Res 2003; 13:2018-29. [PMID: 12952873 PMCID: PMC403674 DOI: 10.1101/gr.1507303] [Citation(s) in RCA: 141] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2003] [Accepted: 07/08/2003] [Indexed: 12/20/2022]
Abstract
Yersinia pestis, the causative agent of plague, diverged from Yersinia pseudotuberculosis, an enteric pathogen, an estimated 1500-20,000 years ago. Genetic characterization of these closely related organisms represents a useful model to study the rapid emergence of bacterial pathogens that threaten mankind. To this end, we undertook genome-wide DNA microarray analysis of 22 strains of Y. pestis and 10 strains of Y. pseudotuberculosis of diverse origin. Eleven Y. pestis DNA loci were deemed absent or highly divergent in all strains of Y. pseudotuberculosis. Four were regions of phage origin, whereas the other seven included genes encoding a vitamin B12 receptor and the insect toxin sepC. Sixteen differences were identified between Y. pestis strains, with biovar Antiqua and Mediaevalis strains showing most divergence from the arrayed CO92 Orientalis strain. Fifty-eight Y. pestis regions were specific to a limited number of Y. pseudotuberculosis strains, including the high pathogenicity island, three putative autotransporters, and several possible insecticidal toxins and hemolysins. The O-antigen gene cluster and one of two possible flagellar operons had high levels of divergence between Y. pseudotuberculosis strains. This study reports chromosomal differences between species, biovars, serotypes, and strains of Y. pestis and Y. pseudotuberculosis that may relate to the evolution of these species in their respective niches.
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Rakin A, Golubov A, Iwobi A, Heesemann J. Tracing acquisitions and losses in Yersinia genomes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 529:19-23. [PMID: 12756721 DOI: 10.1007/0-306-48416-1_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Alexander Rakin
- Max von Pettenkofer-Institute of Hygiene and Medical Microbiology, University of Munich, Pettenkofer Street 9a, 80336, Munich, Germany
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Abstract
In the past few years, an important question in microbiology has arisen from reports indicating that several pathogenic bacteria have evolved virulence factors directed towards a Ras subfamily of GTPases, namely the Rho GTPases. Progress made in studying both the virulence factors and the signaling pathways involving Rho GTPases has shed light on this crosstalk. One central question is raised by the findings that both activating and inactivating virulence factors that target Rho GTPases coexist in some pathogenic bacteria. Further studies on this peculiar aspect of the bacteria-host cell interactions, which leads to the outbreak of infectious diseases, might clarify whether this aspect of Rho GTPase activation or inactivation represents a finely adapted response of the pathogen for its own benefit or might lead to a reaction of the host against the bacteria.
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Affiliation(s)
- Patrice Boquet
- INSERM U452, IFR50, Faculty of Medicine 28 Avenue de Valombrose, 06107 Nice, France.
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Aktories K, Schmidt G. A new turn in Rho GTPase activation by Escherichia coli cytotoxic necrotizing factors. Trends Microbiol 2003; 11:152-5. [PMID: 12706988 DOI: 10.1016/s0966-842x(03)00042-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Various bacterial protein toxins and effectors target Rho GTPases, which are eukaryotic regulators of signal transduction pathways. Many toxins inactivate these GTPases but some, such as the cytotoxic necrotizing factors (CNFs) from Escherichia coli, activate them by deamidation. Recent studies have provided exciting new clues to the functional consequences of the activation of Rho GTPases by CNFs and its effect on the host-pathogen interaction.
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Affiliation(s)
- Klaus Aktories
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Universität Freiburg, Otto-Krayer-Haus, Albertstrasse 25, 79104 Freiburg, Germany.
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50
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Doye A, Mettouchi A, Bossis G, Clément R, Buisson-Touati C, Flatau G, Gagnoux L, Piechaczyk M, Boquet P, Lemichez E. CNF1 exploits the ubiquitin-proteasome machinery to restrict Rho GTPase activation for bacterial host cell invasion. Cell 2002; 111:553-64. [PMID: 12437928 DOI: 10.1016/s0092-8674(02)01132-7] [Citation(s) in RCA: 234] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
CNF1 toxin is a virulence factor produced by uropathogenic Escherichia coli. Upon cell binding and introduction into the cytosol, CNF1 deamidates glutamine 63 of RhoA (or 61 of Rac and Cdc42), rendering constitutively active these GTPases. Unexpectedly, we measured in bladder cells a transient CNF1-induced activation of Rho GTPases, maximal for Rac. Deactivation of Rac correlated with the increased susceptibility of its deamidated form to ubiquitin/proteasome-mediated degradation. Sensitivity to ubiquitylation could be generalized to other permanent-activated forms of Rac and to its sustained activation by Dbl. Degradation of the toxin-activated Rac allowed both host cell motility and efficient cell invasion by uropathogenic bacteria. CNF1 toxicity thus results from a restricted activation of Rho GTPases through hijacking the host cell proteasomal machinery.
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Affiliation(s)
- Anne Doye
- INSERM U452, IFR 50, Faculté de Médecine, 28 avenue de Valombrose, 06107, Nice, France
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