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The Cytolethal Distending Toxin (CDT) is a bacterial genotoxin produced by pathogenic bacteria causing major foodborne diseases worldwide. CDT activates the DNA Damage Response and modulates the host immune response, but the precise relationship between these outcomes has not been addressed so far. Here, we show that chronic exposure to CDT in HeLa cells or mouse embryonic fibroblasts promotes a strong type I interferon (IFN) response that depends on the cytoplasmic DNA sensor cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) synthase (cGAS) through the recognition of micronuclei. Indeed, despite active cell cycle checkpoints and in contrast to other DNA damaging agents, cells exposed to CDT reach mitosis where they accumulate massive DNA damage, resulting in chromosome fragmentation and micronucleus formation in daughter cells. These mitotic phenotypes are observed with CDT from various origins and in cancer or normal cell lines. Finally, we show that CDT exposure in immortalized normal colonic epithelial cells is associated to cGAS protein loss and low type I IFN response, implying that CDT immunomodulatory function may vary depending on tissue and cell type. Thus, our results establish a direct link between CDT-induced DNA damage, genetic instability and the cellular immune response that may be relevant in the context of natural infection associated to chronic inflammation or carcinogenesis.
Benoît J. Pons; Aurélie Pettes-Duler; Claire Naylies; Frédéric Taieb; Catherine Bouchenot; Saleha Hashim; Patrick Rouimi; Maxime Deslande; Yannick Lippi; Gladys Mirey; Julien Vignard. Chronic exposure to Cytolethal Distending Toxin (CDT) promotes a cGAS-dependent type I interferon response. Experientia 2021, 1 -17.
AMA StyleBenoît J. Pons, Aurélie Pettes-Duler, Claire Naylies, Frédéric Taieb, Catherine Bouchenot, Saleha Hashim, Patrick Rouimi, Maxime Deslande, Yannick Lippi, Gladys Mirey, Julien Vignard. Chronic exposure to Cytolethal Distending Toxin (CDT) promotes a cGAS-dependent type I interferon response. Experientia. 2021; ():1-17.
Chicago/Turabian StyleBenoît J. Pons; Aurélie Pettes-Duler; Claire Naylies; Frédéric Taieb; Catherine Bouchenot; Saleha Hashim; Patrick Rouimi; Maxime Deslande; Yannick Lippi; Gladys Mirey; Julien Vignard. 2021. "Chronic exposure to Cytolethal Distending Toxin (CDT) promotes a cGAS-dependent type I interferon response." Experientia , no. : 1-17.
The Cytolethal Distending Toxin (CDT) is a bacterial genotoxin produced by pathogenic bacteria causing major foodborne diseases worldwide. CDT activates the DNA damage response and induces inflammatory signatures in host cells, but the precise relationship between these outcomes has not been addressed so far. Here, we show that the cellular proinflammatory response and senescence induced by CDT depend on the cytoplasmic DNA sensor cGAS through the recognition of micronuclei. Indeed, despite active cell cycle checkpoints and in contrast to other DNA damaging agents, cells exposed to CDT reach mitosis where they accumulate massive DNA damage, resulting in chromosome fragmentation and micronucleus formation in daughter cells. These phenotypes are observed with CDT from various origins and in cancer or normal cell lines. Thus, our results establish a direct link between CDT-induced DNA damage, genetic instability and the cellular inflammatory response that may be relevant in the context of natural infection associated to chronic inflammation or carcinogenesis.
Benoît J. Pons; Aurélie Pettes-Duler; Claire Naylies; Frédéric Taieb; Catherine Bouchenot; Saleha Hashim; Soraya Tadrist; Yannick Lippi; Gladys Mirey; Julien Vignard. The proinflammatory response induced by the Cytolethal Distending Toxin depends on cGAS. 2021, 1 .
AMA StyleBenoît J. Pons, Aurélie Pettes-Duler, Claire Naylies, Frédéric Taieb, Catherine Bouchenot, Saleha Hashim, Soraya Tadrist, Yannick Lippi, Gladys Mirey, Julien Vignard. The proinflammatory response induced by the Cytolethal Distending Toxin depends on cGAS. . 2021; ():1.
Chicago/Turabian StyleBenoît J. Pons; Aurélie Pettes-Duler; Claire Naylies; Frédéric Taieb; Catherine Bouchenot; Saleha Hashim; Soraya Tadrist; Yannick Lippi; Gladys Mirey; Julien Vignard. 2021. "The proinflammatory response induced by the Cytolethal Distending Toxin depends on cGAS." , no. : 1.
The Cytolethal Distending Toxin (CDT) is produced by many Gram-negative pathogenic bacteria responsible for major foodborne diseases worldwide. CDT induces DNA damage and cell cycle arrest in host-cells, eventually leading to senescence or apoptosis. According to structural and sequence comparison, the catalytic subunit CdtB is suggested to possess both nuclease and phosphatase activities, carried by a single catalytic site. However, the impact of each activity on cell-host toxicity is yet to be characterized. Here, we analyze the consequences of cell exposure to different CDT mutated on key CdtB residues, focusing on cell viability, cell cycle defects, and DNA damage induction. A first class of mutant, devoid of any activity, targets putative catalytic (H160A), metal binding (D273R), and DNA binding residues (R117A-R144A-N201A). The second class of mutants (A163R, F156-T158, and the newly identified G114T), which gathers mutations on residues potentially involved in lipid substrate binding, has only partially lost its toxic effects. However, their defects are alleviated when CdtB is artificially introduced inside cells, except for the F156-T158 double mutant that is defective in nuclear addressing. Therefore, our data reveal that CDT toxicity is mainly correlated to CdtB nuclease activity, whereas phosphatase activity may probably be involved in CdtB intracellular trafficking.
Benoît J. Pons; Nicolas Loiseau; Saleha Hashim; Soraya Tadrist; Gladys Mirey; Julien Vignard. Functional Study of Haemophilus ducreyi Cytolethal Distending Toxin Subunit B. Toxins 2020, 12, 530 .
AMA StyleBenoît J. Pons, Nicolas Loiseau, Saleha Hashim, Soraya Tadrist, Gladys Mirey, Julien Vignard. Functional Study of Haemophilus ducreyi Cytolethal Distending Toxin Subunit B. Toxins. 2020; 12 (9):530.
Chicago/Turabian StyleBenoît J. Pons; Nicolas Loiseau; Saleha Hashim; Soraya Tadrist; Gladys Mirey; Julien Vignard. 2020. "Functional Study of Haemophilus ducreyi Cytolethal Distending Toxin Subunit B." Toxins 12, no. 9: 530.
The Cytolethal Distending Toxin (CDT) is a bacterial genotoxin that activates the DNA damage response and induces inflammatory signatures in host cells, but the precise relationship between these outcomes has not been addressed so far. CDT induces a singular time-dependent increase of DNA damage and cell cycle defects, questioning on possible impaired response to this toxin over the cell cycle. Here, we identify mitosis as a crucial phase during CDT intoxination. Despite active cell cycle checkpoints and in contrast to other DNA damaging agents, CDT-exposed cells reach mitosis where they accumulate massive DNA damage, resulting in chromosome fragmentation and micronucleus formation. These micronuclei are recognized by cGAS that elicits an inflammatory signature resulting in cell distention and senescence. Our results unravel for the first time the mitotic consequences of CDT genotoxic activity and relate them to pro-inflammatory cellular response. These findings may have important implications during bacterial infection regarding CDT-mediated immunomodulatory and tumorigenic processes.
Benoît Pons; Aurélie Pettes-Duler; Claire Naylies; Frédéric Taieb; Saleha Hashim; Soraya Tadrist; Yannick Lippi; Gladys Mirey; Julien Vignard. Cytolethal Distending Toxin: from mitotic DNA damage to cGAS-dependent pro-inflammatory response. bioRxiv 2020, 1 .
AMA StyleBenoît Pons, Aurélie Pettes-Duler, Claire Naylies, Frédéric Taieb, Saleha Hashim, Soraya Tadrist, Yannick Lippi, Gladys Mirey, Julien Vignard. Cytolethal Distending Toxin: from mitotic DNA damage to cGAS-dependent pro-inflammatory response. bioRxiv. 2020; ():1.
Chicago/Turabian StyleBenoît Pons; Aurélie Pettes-Duler; Claire Naylies; Frédéric Taieb; Saleha Hashim; Soraya Tadrist; Yannick Lippi; Gladys Mirey; Julien Vignard. 2020. "Cytolethal Distending Toxin: from mitotic DNA damage to cGAS-dependent pro-inflammatory response." bioRxiv , no. : 1.
The Cytolethal Distending Toxin (CDT) is a bacterial virulence factor produced by several Gram-negative pathogenic bacteria. These bacteria, found in distinct niches, cause diverse infectious diseases and produce CDTs differing in sequence and structure. CDTs have been involved in the pathogenicity of the associated bacteria by promoting persistent infection. At the host-cell level, CDTs cause cell distension, cell cycle block and DNA damage, eventually leading to cell death. All these effects are attributable to the catalytic CdtB subunit, but its exact mode of action is only beginning to be unraveled. Sequence and 3D structure analyses revealed similarities with better characterized proteins, such as nucleases or phosphatases, and it has been hypothesized that CdtB exerts a biochemical activity close to those enzymes. Here, we review the relationships that have been established between CdtB structure and function, particularly by mutation experiments on predicted key residues in different experimental systems. We discuss the relevance of these approaches and underline the importance of further study in the molecular mechanisms of CDT toxicity, particularly in the context of different pathological conditions.
Benoît Pons; Julien Vignard; Gladys Mirey. Cytolethal Distending Toxin Subunit B: A Review of Structure–Function Relationship. Toxins 2019, 11, 595 .
AMA StyleBenoît Pons, Julien Vignard, Gladys Mirey. Cytolethal Distending Toxin Subunit B: A Review of Structure–Function Relationship. Toxins. 2019; 11 (10):595.
Chicago/Turabian StyleBenoît Pons; Julien Vignard; Gladys Mirey. 2019. "Cytolethal Distending Toxin Subunit B: A Review of Structure–Function Relationship." Toxins 11, no. 10: 595.
The classification of the fungicide captan (CAS Number: 133‐06‐2) as a carcinogen agent is presently under discussion. Despite the mutagenic effect detected by the Ames test and carcinogenic properties observed in mice, the genotoxicity of this pesticide in humans is still unclear. New information is needed about its mechanism of action in mammalian cells. Here we show that Chinese Hamster Ovary (CHO) cells exposed to captan accumulate Fpg‐sensitive DNA base alterations. In CHO and HeLa cells, such DNA lesions require the XRCC1‐dependent pathway to be repaired and induce a replicative stress that activated the ATR signalling response and resulted in double‐strand breaks and micronuclei. The replicative stress is characterized by a dramatic decrease in DNA synthesis due to a reduced replication fork progression. However, impairment of the XRCC1‐related repair process did not amplify the replicative stress, suggesting that the fork progression defect is independent from the presence of base modifications. These results support the involvement of at least two independent pathways in the genotoxic effect of captan that might play a key role in carcinogenesis. This article is protected by copyright. All rights reserved.
Anne Fernandez-Vidal; Liana C. Arnaud; Manon Maumus; Marianne Chevalier; Gladys Mirey; Bernard Salles; Julien Vignard; Elisa Boutet-Robinet. Exposure to the Fungicide Captan Induces DNA Base Alterations and Replicative Stress in Mammalian Cells. Environmental and Molecular Mutagenesis 2018, 60, 286 -297.
AMA StyleAnne Fernandez-Vidal, Liana C. Arnaud, Manon Maumus, Marianne Chevalier, Gladys Mirey, Bernard Salles, Julien Vignard, Elisa Boutet-Robinet. Exposure to the Fungicide Captan Induces DNA Base Alterations and Replicative Stress in Mammalian Cells. Environmental and Molecular Mutagenesis. 2018; 60 (3):286-297.
Chicago/Turabian StyleAnne Fernandez-Vidal; Liana C. Arnaud; Manon Maumus; Marianne Chevalier; Gladys Mirey; Bernard Salles; Julien Vignard; Elisa Boutet-Robinet. 2018. "Exposure to the Fungicide Captan Induces DNA Base Alterations and Replicative Stress in Mammalian Cells." Environmental and Molecular Mutagenesis 60, no. 3: 286-297.
ObjectiveCampylobacter jejuni produces a genotoxin, cytolethal distending toxin (CDT), which has DNAse activity and causes DNA double-strand breaks. Although C. jejuni infection has been shown to promote intestinal inflammation, the impact of this bacterium on carcinogenesis has never been examined.DesignGerm-free (GF) ApcMin/+mice, fed with 1% dextran sulfate sodium, were used to test tumorigenesis potential of CDT-producing C. jejuni. Cells and enteroids were exposed to bacterial lysates to determine DNA damage capacity via γH2AX immunofluorescence, comet assay and cell cycle assay. To examine the interplay of CDT-producing C. jejuni, gut microbiome and host in tumorigenesis, colonic RNA-sequencing and faecal 16S rDNA sequencing were performed. Rapamycin was administrated to investigate the prevention of CDT-producing C. jejuni-induced tumorigenesis.ResultsGF ApcMin/+mice colonised with human clinical isolate C. jejuni81–176 developed significantly more and larger tumours when compared with uninfected mice. C. jejuni with a mutated cdtB subunit, mutcdtB, attenuated C. jejuni-induced tumorigenesis in vivo and decreased DNA damage response in cells and enteroids. C. jejuni infection induced expression of hundreds of colonic genes, with 22 genes dependent on the presence of cdtB. The C. jejuni-infected group had a significantly different microbial gene expression profile compared with the mutcdtB group as shown by metatranscriptomic data, and different microbial communities as measured by 16S rDNA sequencing. Finally, rapamycin could diminish the tumorigenic capability of C. jejuni.ConclusionHuman clinical isolate C. jejuni 81–176 promotes colorectal cancer and induces changes in microbial composition and transcriptomic responses, a process dependent on CDT production.
Zhen He; Raad Z Gharaibeh; Rachel C Newsome; Jllian L Pope; Michael Dougherty; Sarah Tomkovich; Benoit Pons; Gladys Mirey; Julien Vignard; David R Hendrixson; Christian Jobin. Campylobacter jejuni promotes colorectal tumorigenesis through the action of cytolethal distending toxin. Gut 2018, 68, 289 -300.
AMA StyleZhen He, Raad Z Gharaibeh, Rachel C Newsome, Jllian L Pope, Michael Dougherty, Sarah Tomkovich, Benoit Pons, Gladys Mirey, Julien Vignard, David R Hendrixson, Christian Jobin. Campylobacter jejuni promotes colorectal tumorigenesis through the action of cytolethal distending toxin. Gut. 2018; 68 (2):289-300.
Chicago/Turabian StyleZhen He; Raad Z Gharaibeh; Rachel C Newsome; Jllian L Pope; Michael Dougherty; Sarah Tomkovich; Benoit Pons; Gladys Mirey; Julien Vignard; David R Hendrixson; Christian Jobin. 2018. "Campylobacter jejuni promotes colorectal tumorigenesis through the action of cytolethal distending toxin." Gut 68, no. 2: 289-300.
Through diet, people are exposed simultaneously to a variety of contaminants (e.g. heavy metals, mycotoxins, pesticides) that could have combined adverse effects on human health. A previous study identified six main mixtures of food contaminants to which French adult consumers are exposed. These complex mixtures are comprised of 11 to 19 chemicals that have numerous toxic properties. In the present study, we investigated the genotoxic effects of these food contaminants, as single molecules and in mixtures that reflect their occurrence in the French diet, using the γH2AX assay in two human cell lines (HepG2, LS‐174 T). Results of detailed analysis of the 49 individual contaminants (including 21 tested in this study) demonstrated a positive genotoxic response to 14 contaminants in HepG2 and 12 in LS‐174 T cells. Next, our results indicated that two mixtures out of six triggered significant γH2AX induction after 24 hr of treatment, at concentrations for which individual compounds did not induce any DNA damage, suggesting more than additive interactions between chemicals. γH2AX positive mixtures were then tested for mutagenicity with the innovative in vitro PIG‐A assay in HepG2 cells coupled with the soft agar colony formation assay. The two γH2AX positive mixtures led to a significant increase in the frequency of PIG‐A GPI‐deficient cells and in the number of colonies formed in soft agar. In conclusion, our study demonstrates that two mixtures of contaminants present in the French diet induce genotoxicity and mutagenicity, and that the combined effects of single molecules present in these mixtures are likely not additive, highlighting potential problems for hazard assessment of mixtures.
B. Kopp; Julien Vignard; Gladys Mirey; V. Fessard; D. Zalko; L. Le Hgarat; M. Audebert. Genotoxicity and mutagenicity assessment of food contaminant mixtures present in the French diet. Environmental and Molecular Mutagenesis 2018, 59, 742 -754.
AMA StyleB. Kopp, Julien Vignard, Gladys Mirey, V. Fessard, D. Zalko, L. Le Hgarat, M. Audebert. Genotoxicity and mutagenicity assessment of food contaminant mixtures present in the French diet. Environmental and Molecular Mutagenesis. 2018; 59 (8):742-754.
Chicago/Turabian StyleB. Kopp; Julien Vignard; Gladys Mirey; V. Fessard; D. Zalko; L. Le Hgarat; M. Audebert. 2018. "Genotoxicity and mutagenicity assessment of food contaminant mixtures present in the French diet." Environmental and Molecular Mutagenesis 59, no. 8: 742-754.
Colibactins are hybrid polyketide-nonribosomal peptides produced by Escherichia coli , Klebsiella pneumoniae , and other Enterobacteriaceae harboring the pks genomic island. These genotoxic metabolites are produced by pks -encoded peptide-polyketide synthases as inactive prodrugs called precolibactins, which are then converted to colibactins by deacylation for DNA-damaging effects. Colibactins are bona fide virulence factors and are suspected of promoting colorectal carcinogenesis when produced by intestinal E. coli . Natural active colibactins have not been isolated, and how they induce DNA damage in the eukaryotic host cell is poorly characterized. Here, we show that DNA strands are cross-linked covalently when exposed to enterobacteria producing colibactins. DNA cross-linking is abrogated in a clbP mutant unable to deacetylate precolibactins or by adding the colibactin self-resistance protein ClbS, confirming the involvement of the mature forms of colibactins. A similar DNA-damaging mechanism is observed in cellulo , where interstrand cross-links are detected in the genomic DNA of cultured human cells exposed to colibactin-producing bacteria. The intoxicated cells exhibit replication stress, activation of ataxia-telangiectasia and Rad3-related kinase (ATR), and recruitment of the DNA cross-link repair Fanconi anemia protein D2 (FANCD2) protein. In contrast, inhibition of ATR or knockdown of FANCD2 reduces the survival of cells exposed to colibactin-producing bacteria. These findings demonstrate that DNA interstrand cross-linking is the critical mechanism of colibactin-induced DNA damage in infected cells. IMPORTANCE Colorectal cancer is the third-most-common cause of cancer death. In addition to known risk factors such as high-fat diets and alcohol consumption, genotoxic intestinal Escherichia coli bacteria producing colibactin are proposed to play a role in colon cancer development. Here, by using transient infections with genotoxic E. coli , we showed that colibactins directly generate DNA cross-links in cellulo . Such lesions are converted into double-strand breaks during the repair response. DNA cross-links, akin to those induced by metabolites of alcohol and high-fat diets and by widely used anticancer drugs, are both severely mutagenic and profoundly cytotoxic lesions. This finding of a direct induction of DNA cross-links by a bacterium should facilitate delineating the role of E. coli in colon cancer and engineering new anticancer agents.
Nadège Bossuet-Greif; Julien Vignard; Frédéric Taieb; Gladys Mirey; Damien Dubois; Claude Petit; Eric Oswald; Jean-Philippe Nougayrede. The Colibactin Genotoxin Generates DNA Interstrand Cross-Links in Infected Cells. mBio 2018, 9, e02393-17 .
AMA StyleNadège Bossuet-Greif, Julien Vignard, Frédéric Taieb, Gladys Mirey, Damien Dubois, Claude Petit, Eric Oswald, Jean-Philippe Nougayrede. The Colibactin Genotoxin Generates DNA Interstrand Cross-Links in Infected Cells. mBio. 2018; 9 (2):e02393-17.
Chicago/Turabian StyleNadège Bossuet-Greif; Julien Vignard; Frédéric Taieb; Gladys Mirey; Damien Dubois; Claude Petit; Eric Oswald; Jean-Philippe Nougayrede. 2018. "The Colibactin Genotoxin Generates DNA Interstrand Cross-Links in Infected Cells." mBio 9, no. 2: e02393-17.
Vanessa Graillot; Thibault Metenier; Odile Mondesert; Julien Vignard; Valerie Lobjois; Emmanuelle Bazin; Sandrine Camus; Christiane Guguen-Guillouzo; Ruoya Li; Christophe Chesne; Bernard Ducommun; Bernard Salles; Gladys Mirey. Use of a reliable metabolically competent human RGHep + hepatocyte model engineered with biological tracers for in vitro micronucleus test associating high-content imaging. Drug Metabolism and Pharmacokinetics 2018, 33, S59 .
AMA StyleVanessa Graillot, Thibault Metenier, Odile Mondesert, Julien Vignard, Valerie Lobjois, Emmanuelle Bazin, Sandrine Camus, Christiane Guguen-Guillouzo, Ruoya Li, Christophe Chesne, Bernard Ducommun, Bernard Salles, Gladys Mirey. Use of a reliable metabolically competent human RGHep + hepatocyte model engineered with biological tracers for in vitro micronucleus test associating high-content imaging. Drug Metabolism and Pharmacokinetics. 2018; 33 (1):S59.
Chicago/Turabian StyleVanessa Graillot; Thibault Metenier; Odile Mondesert; Julien Vignard; Valerie Lobjois; Emmanuelle Bazin; Sandrine Camus; Christiane Guguen-Guillouzo; Ruoya Li; Christophe Chesne; Bernard Ducommun; Bernard Salles; Gladys Mirey. 2018. "Use of a reliable metabolically competent human RGHep + hepatocyte model engineered with biological tracers for in vitro micronucleus test associating high-content imaging." Drug Metabolism and Pharmacokinetics 33, no. 1: S59.
Within the nucleus, sub-nuclear domains define territories where specific functions occur. Nuclear bodies (NBs) are dynamic structures that concentrate nuclear factors and that can be observed microscopically. Recently, NBs containing the p53 binding protein 1 (53BP1), a key component of the DNA damage response, were defined. Interestingly, 53BP1 NBs are visualized during G1 phase, in daughter cells, while DNA damage was generated in mother cells and not properly processed. Unlike most NBs involved in transcriptional processes, replication has proven to be key for 53BP1 NBs, with replication stress leading to the formation of these large chromatin domains in daughter cells. In this review, we expose the composition and organization of 53BP1 NBs and focus on recent findings regarding their regulation and dynamics. We then concentrate on the importance of the replication stress, examine the relation of 53BP1 NBs with DNA damage and discuss their dysfunction.
Anne Fernandez-Vidal; Julien Vignard; Gladys Mirey. Around and beyond 53BP1 Nuclear Bodies. International Journal of Molecular Sciences 2017, 18, 2611 .
AMA StyleAnne Fernandez-Vidal, Julien Vignard, Gladys Mirey. Around and beyond 53BP1 Nuclear Bodies. International Journal of Molecular Sciences. 2017; 18 (12):2611.
Chicago/Turabian StyleAnne Fernandez-Vidal; Julien Vignard; Gladys Mirey. 2017. "Around and beyond 53BP1 Nuclear Bodies." International Journal of Molecular Sciences 18, no. 12: 2611.
Gladys Mirey; Vanessa Graillot; Odile Mondesert; Thibault Metenier; Julien Vignard; Valerie Lobjois; Emmanuelle Bazin; Valery Shevchenko; Christiane Guguen-Guillouzo; Christophe Chesne; Bernard Ducommun; Bernard Salles. In vitro micronucleus test in living cells associating biological tracers and high-content imaging. Toxicology Letters 2017, 280, S322 .
AMA StyleGladys Mirey, Vanessa Graillot, Odile Mondesert, Thibault Metenier, Julien Vignard, Valerie Lobjois, Emmanuelle Bazin, Valery Shevchenko, Christiane Guguen-Guillouzo, Christophe Chesne, Bernard Ducommun, Bernard Salles. In vitro micronucleus test in living cells associating biological tracers and high-content imaging. Toxicology Letters. 2017; 280 ():S322.
Chicago/Turabian StyleGladys Mirey; Vanessa Graillot; Odile Mondesert; Thibault Metenier; Julien Vignard; Valerie Lobjois; Emmanuelle Bazin; Valery Shevchenko; Christiane Guguen-Guillouzo; Christophe Chesne; Bernard Ducommun; Bernard Salles. 2017. "In vitro micronucleus test in living cells associating biological tracers and high-content imaging." Toxicology Letters 280, no. : S322.
Marie Liamin; Elisa Boutet-Robinet; Emilien L. Jamin; Morgane Fernier; Laure Khoury; Benjamin Kopp; Eric Le Ferrec; Julien Vignard; Marc Audebert; Lydie Sparfel. Benzo[a]pyrene-induced DNA damage associated with mutagenesis in primary human activated T lymphocytes. Toxicology Letters 2017, 280, S114 .
AMA StyleMarie Liamin, Elisa Boutet-Robinet, Emilien L. Jamin, Morgane Fernier, Laure Khoury, Benjamin Kopp, Eric Le Ferrec, Julien Vignard, Marc Audebert, Lydie Sparfel. Benzo[a]pyrene-induced DNA damage associated with mutagenesis in primary human activated T lymphocytes. Toxicology Letters. 2017; 280 ():S114.
Chicago/Turabian StyleMarie Liamin; Elisa Boutet-Robinet; Emilien L. Jamin; Morgane Fernier; Laure Khoury; Benjamin Kopp; Eric Le Ferrec; Julien Vignard; Marc Audebert; Lydie Sparfel. 2017. "Benzo[a]pyrene-induced DNA damage associated with mutagenesis in primary human activated T lymphocytes." Toxicology Letters 280, no. : S114.
International audiencePolycyclic aromatic hydrocarbons (PAHs), such as benzo[a]pyrene (B[a]P), are widely distributed environmental contaminants exerting toxic effects such as genotoxicity and carcinogenicity, mainly associated with aryl hydrocarbon receptor (AhR) activation and the subsequent induction of cytochromes P-450 (CYP) 1-metabolizing enzymes. We previously reported an up-regulation of AhR expression and activity in primary cultures of human T lymphocyte by a physiological activation. Despite the suggested link between exposure to PAHs and the risk of lymphoma, the potential of activated human T lymphocytes to metabolize AhR exogenous ligands such as B[a]P, and produce DNA damage has not been investigated. In the present study, we characterized the genotoxic response of primary activated T lymphocytes to B[a] P. We demonstrated that, following T lymphocyte activation, B[a]P treatment triggers a marked increase in CYP1 expression and activity generating, upon metabolic activation, DNA adducts and double-strand breaks (DSBs) after a 48-h treatment. At this time point, B[a]P also induces a DNA damage response with ataxia telangiectasia mutated kinase activation, thus producing a p53-dependent response and T lymphocyte survival. B[a]P activates DSB repair by mobilizing homologous recombination machinery but also induces gene mutations in activated human T lymphocytes which could consequently drive a cancer process. In conclusion, primary cultures of activated human T lymphocytes represent a good model for studying genotoxic effects of environmental contaminants such as PAHs, and predicting human health issues
Marie Liamin; Elisa Boutet-Robinet; Emilien L. Jamin; Morgane Fernier; Laure Khoury; Benjamin Kopp; Eric Le Ferrec; Julien Vignard; Marc Audebert; Lydie Sparfel. Benzo[a]pyrene-induced DNA damage associated with mutagenesis in primary human activated T lymphocytes. Biochemical Pharmacology 2017, 137, 113 -124.
AMA StyleMarie Liamin, Elisa Boutet-Robinet, Emilien L. Jamin, Morgane Fernier, Laure Khoury, Benjamin Kopp, Eric Le Ferrec, Julien Vignard, Marc Audebert, Lydie Sparfel. Benzo[a]pyrene-induced DNA damage associated with mutagenesis in primary human activated T lymphocytes. Biochemical Pharmacology. 2017; 137 ():113-124.
Chicago/Turabian StyleMarie Liamin; Elisa Boutet-Robinet; Emilien L. Jamin; Morgane Fernier; Laure Khoury; Benjamin Kopp; Eric Le Ferrec; Julien Vignard; Marc Audebert; Lydie Sparfel. 2017. "Benzo[a]pyrene-induced DNA damage associated with mutagenesis in primary human activated T lymphocytes." Biochemical Pharmacology 137, no. : 113-124.
The Cytolethal Distending Toxin (CDT), produced by many bacteria, has been associated with various diseases including cancer. CDT induces DNA double-strand breaks (DSBs), leading to cell death or mutagenesis if misrepaired. At low doses of CDT, other DNA lesions precede replication-dependent DSB formation, implying that non-DSB repair mechanisms may contribute to CDT cell resistance. To address this question, we developed a proliferation assay using human cell lines specifically depleted in each of the main DNA repair pathways. Here, we validate the involvement of the two major DSB repair mechanisms, Homologous Recombination and Non Homologous End Joining, in the management of CDT-induced lesions. We show that impairment of single-strand break repair (SSBR), but not nucleotide excision repair, sensitizes cells to CDT, and we explore the interplay of SSBR with the DSB repair mechanisms. Finally, we document the role of the replicative stress response and demonstrate the involvement of the Fanconi Anemia repair pathway in response to CDT. In conclusion, our work indicates that cellular survival to CDT-induced DNA damage involves different repair pathways, in particular SSBR. This reinforces a model where CDT-related genotoxicity primarily involves SSBs rather than DSBs, underlining the importance of cell proliferation during CDT intoxication and pathogenicity.
Elisabeth Bezine; Yann Malaisé; Aurore Loeuillet; Marianne Chevalier; Elisa Boutet-Robinet; Bernard Salles; Gladys Mirey; Julien Vignard. Cell resistance to the Cytolethal Distending Toxin involves an association of DNA repair mechanisms. Scientific Reports 2016, 6, 36022 .
AMA StyleElisabeth Bezine, Yann Malaisé, Aurore Loeuillet, Marianne Chevalier, Elisa Boutet-Robinet, Bernard Salles, Gladys Mirey, Julien Vignard. Cell resistance to the Cytolethal Distending Toxin involves an association of DNA repair mechanisms. Scientific Reports. 2016; 6 (1):36022.
Chicago/Turabian StyleElisabeth Bezine; Yann Malaisé; Aurore Loeuillet; Marianne Chevalier; Elisa Boutet-Robinet; Bernard Salles; Gladys Mirey; Julien Vignard. 2016. "Cell resistance to the Cytolethal Distending Toxin involves an association of DNA repair mechanisms." Scientific Reports 6, no. 1: 36022.
V. Graillot; O. Mondesert; T. Méténier; J. Vignard; V. Lobjois; E. Bazin; V. Shevchenko; C. Guillouzo; C. Chesné; B. Ducommun; B. Salles; G. Mirey. A new in vitro micronucleus test in living cells associating biological tracers and high-content imaging. Toxicology Letters 2016, 258, S146 .
AMA StyleV. Graillot, O. Mondesert, T. Méténier, J. Vignard, V. Lobjois, E. Bazin, V. Shevchenko, C. Guillouzo, C. Chesné, B. Ducommun, B. Salles, G. Mirey. A new in vitro micronucleus test in living cells associating biological tracers and high-content imaging. Toxicology Letters. 2016; 258 ():S146.
Chicago/Turabian StyleV. Graillot; O. Mondesert; T. Méténier; J. Vignard; V. Lobjois; E. Bazin; V. Shevchenko; C. Guillouzo; C. Chesné; B. Ducommun; B. Salles; G. Mirey. 2016. "A new in vitro micronucleus test in living cells associating biological tracers and high-content imaging." Toxicology Letters 258, no. : S146.
The composition of the human microbiota influences tumorigenesis, notably in colorectal cancer (CRC). Pathogenic Escherichia coli possesses a variety of virulent factors, among them the Cytolethal Distending Toxin (CDT). CDT displays dual DNase and phosphatase activities and induces DNA double strand breaks, cell cycle arrest and apoptosis in a broad range of mammalian cells. As CDT could promote malignant transformation, we investigated the cellular outcomes induced by acute and chronic exposures to E. coli CDT in normal human colon epithelial cells (HCECs). Moreover, we conducted a comparative study between isogenic derivatives cell lines of the normal HCECs in order to mimic the mutation of three major genes found in CRC genetic models: APC, KRAS, and TP53. Our results demonstrate that APC and p53 deficient cells showed impaired DNA damage response after CDT exposure, whereas HCECs expressing oncogenic KRASV12 were more resistant to CDT. Compared to normal HCECs, the precancerous derivatives exhibit hallmarks of malignant transformation after a chronic exposure to CDT. HCECs defective in APC and p53 showed enhanced anchorage independent growth and genetic instability, assessed by the micronucleus formation assay. In contrast, the ability to grow independently of anchorage was not impacted by CDT chronic exposure in KRASV12 HCECs, but micronucleus formation is dramatically increased. Thus, CDT does not initiate CRC by itself, but may have promoting effects in premalignant HCECs, involving different mechanisms in function of the genetic alterations associated to CRC.
Vanessa Graillot; Inge Dormoy; Jacques Dupuy; Jerry W. Shay; Laurence Huc; Gladys Mirey; Julien Vignard. Genotoxicity of Cytolethal Distending Toxin (CDT) on Isogenic Human Colorectal Cell Lines: Potential Promoting Effects for Colorectal Carcinogenesis. Frontiers in Cellular and Infection Microbiology 2016, 6, 34 .
AMA StyleVanessa Graillot, Inge Dormoy, Jacques Dupuy, Jerry W. Shay, Laurence Huc, Gladys Mirey, Julien Vignard. Genotoxicity of Cytolethal Distending Toxin (CDT) on Isogenic Human Colorectal Cell Lines: Potential Promoting Effects for Colorectal Carcinogenesis. Frontiers in Cellular and Infection Microbiology. 2016; 6 ():34.
Chicago/Turabian StyleVanessa Graillot; Inge Dormoy; Jacques Dupuy; Jerry W. Shay; Laurence Huc; Gladys Mirey; Julien Vignard. 2016. "Genotoxicity of Cytolethal Distending Toxin (CDT) on Isogenic Human Colorectal Cell Lines: Potential Promoting Effects for Colorectal Carcinogenesis." Frontiers in Cellular and Infection Microbiology 6, no. : 34.
Chromatin function is involved in many cellular processes, its visualization or modification being essential in many developmental or cellular studies. Here, we present the characterization of chromatibody, a chromatin-binding single-domain, and explore its use in living cells. This non-intercalating tool specifically binds the heterodimer of H2A-H2B histones and displays a versatile reactivity, specifically labeling chromatin from yeast to mammals. We show that this genetically-encoded probe, when fused to fluorescent proteins, allows non–invasive real-time chromatin imaging. Chromatibody is a dynamic chromatin probe that can be modulated. Finally, chromatibody is an efficient tool to target an enzymatic activity to the nucleosome, such as the DNA damage-dependent H2A ubiquitination, modifying this epigenetic mark at the scale of the genome and resulting in DNA damage signaling and repair defects. Altogether, these results identify chromatibody as a universal non-invasive tool for either in vivo chromatin imaging or to manipulate the chromatin landscape.
Denis Jullien; Julien Vignard; Yoann Fedor; Nicolas Bery; Aurelien Olichon; Michèle Crozatier; Monique Erard; Hervé Cassard; Bernard Ducommun; Bernard Salles; Gladys Mirey. Chromatibody, a novel non-invasive molecular tool to explore and manipulate chromatin in living cells. Journal of Cell Science 2016, 129, 2673 -2683.
AMA StyleDenis Jullien, Julien Vignard, Yoann Fedor, Nicolas Bery, Aurelien Olichon, Michèle Crozatier, Monique Erard, Hervé Cassard, Bernard Ducommun, Bernard Salles, Gladys Mirey. Chromatibody, a novel non-invasive molecular tool to explore and manipulate chromatin in living cells. Journal of Cell Science. 2016; 129 (13):2673-2683.
Chicago/Turabian StyleDenis Jullien; Julien Vignard; Yoann Fedor; Nicolas Bery; Aurelien Olichon; Michèle Crozatier; Monique Erard; Hervé Cassard; Bernard Ducommun; Bernard Salles; Gladys Mirey. 2016. "Chromatibody, a novel non-invasive molecular tool to explore and manipulate chromatin in living cells." Journal of Cell Science 129, no. 13: 2673-2683.
The cytolethal distending toxin (CDT) is produced by many pathogenic Gram-negative bacteria and is considered as a virulence factor. In human cells, CDT exposure leads to a unique cytotoxicity associated with a characteristic cell distension and induces a cell cycle arrest dependent on the DNA damage response (DDR) triggered by DNA double-strand breaks (DSBs). CDT has thus been classified as a cyclomodulin and a genotoxin. Whereas unrepaired damage can lead to cell death, effective, but improper repair may be detrimental. Indeed, improper repair of DNA damage may allow cells to resume the cell cycle and induce genetic instability, a hallmark in cancer. In vivo, CDT has been shown to induce the development of dysplastic nodules and to lead to genetic instability, defining CDT as a potential carcinogen. It is therefore important to characterize the outcome of the CDT-induced DNA damage and the consequences for intoxicated cells and organisms. Here, we review the latest results regarding the host cell response to CDT intoxication and focus on DNA damage characteristics, cell cycle modulation and cell outcomes.
Elisabeth Bezine; Julien Vignard; Gladys Mirey. The Cytolethal Distending Toxin Effects on Mammalian Cells: A DNA Damage Perspective. Cells 2014, 3, 592 -615.
AMA StyleElisabeth Bezine, Julien Vignard, Gladys Mirey. The Cytolethal Distending Toxin Effects on Mammalian Cells: A DNA Damage Perspective. Cells. 2014; 3 (2):592-615.
Chicago/Turabian StyleElisabeth Bezine; Julien Vignard; Gladys Mirey. 2014. "The Cytolethal Distending Toxin Effects on Mammalian Cells: A DNA Damage Perspective." Cells 3, no. 2: 592-615.
The occurrence of DNA double-strand breaks (DSBs) induced by ionizing radiation has been extensively studied by biochemical or cell imaging techniques. Cell imaging development relies on technical advances as well as our knowledge of the cell DNA damage response (DDR) process. The DDR involves a complex network of proteins that initiate and coordinate DNA damage signaling and repair activities. As some DDR proteins assemble at DSBs in an established spatio-temporal pattern, visible nuclear foci are produced. In addition, post-translational modifications are important for the signaling and the recruitment of specific partners at damaged chromatin foci. We briefly review here the most widely used methods to study DSBs. We also discuss the development of indirect methods, using reporter expression or intra-nuclear antibodies, to follow the production of DSBs in real time and in living cells
Julien Vignard; Gladys Mirey; Bernard Salles. Ionizing-radiation induced DNA double-strand breaks: A direct and indirect lighting up. Radiotherapy and Oncology 2013, 108, 362 -369.
AMA StyleJulien Vignard, Gladys Mirey, Bernard Salles. Ionizing-radiation induced DNA double-strand breaks: A direct and indirect lighting up. Radiotherapy and Oncology. 2013; 108 (3):362-369.
Chicago/Turabian StyleJulien Vignard; Gladys Mirey; Bernard Salles. 2013. "Ionizing-radiation induced DNA double-strand breaks: A direct and indirect lighting up." Radiotherapy and Oncology 108, no. 3: 362-369.