Consulta: creatorFacets:"Destoumieux-garzon, Delphine"
Registros recuperados: 25
Data/hora: 17/06/2024 02:48:28

Innate Immune Responses of a Scleractinian Coral to Vibriosis
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Vidal-dupiol, Jeremie; Ladriere, Ophelie; Destoumieux-garzon, Delphine; Sautiere, Pierre-eric; Meistertzheim, Anne-leila; Tambutte, Eric; Tambutte, Sylvie; Duval, David; Foure, Laurent; Adjeroud, Mehdi; Mitta, Guillaume.
Scleractinian corals are the most basal eumetazoan taxon and provide the biological and physical framework for coral reefs, which are among the most diverse of all ecosystems. Over the past three decades and coincident with climate change, these phototrophic symbiotic organisms have been subject to increasingly frequent and severe diseases, which are now geographically widespread and a major threat to these ecosystems. Although coral immunity has been the subject of increasing study, the available information remains fragmentary, especially with respect to coral antimicrobial responses. In this study, we characterized damicornin from Pocillopora damicornis, the first scleractinian antimicrobial peptide (AMP) to be reported. We found that its precursor has...
Tipo: Text
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00039/14996/12433.pdf

csrB Gene Duplication Drives the Evolution of Redundant Regulatory Pathways Controlling Expression of the Major Toxic Secreted Metalloproteases in Vibrio tasmaniensis LGP32
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Nguyen, An Ngoc; Disconzi, Elena; Charriere, Guillaume; Destoumieux-garzon, Delphine; Bouloc, Philippe; Le Roux, Frederique; Jacq, Annick.
CsrBs are bacterial highly conserved and multiple-copy noncoding small RNAs (sRNAs) that play major roles in cell physiology and virulence. In the Vibrio genus, they are known to be regulated by the two-component system VarSNarA. They modulate the well-characterized quorum sensing pathway controlling virulence and luminescence in Vibrio cholerae and Vibrio harveyi, respectively. Remarkably, Vibrio tasmaniensis LGP32, an oyster pathogen that belongs to the Splendidus Glade, was found to have four copies of csrB, named csrB1-4, compared to two to three copies in other Vibrio species. Here, we show that the extra csrB4 copy results from a csrB3 gene duplication, a characteristic of the Splendidus Glade. Interestingly, csrB genes are regulated in different...
Tipo: Text
Palavras-chave: Bacterial gene regulation; Bacterial sRNAs; Transcriptomics; Vibrio pathogenic to oysters; Host-pathogen interactions.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00476/58785/61319.pdf

Immune-suppression by OsHV-1 viral infection causes fatal bacteraemia in Pacific oysters
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: De Lorgeril, Julien; Lucasson, Aude; Petton, Bruno; Toulza, Eve; Montagnani, Caroline; Clerissi, Camille; Vidal-dupiol, Jeremie; Chaparro, Cristian; Galinier, Richard; Escoubas, Jean Michel; Haffner, Philippe; Degremont, Lionel; Charriere, Guillaume; Lafont, Maxime; Delort, Abigail; Vergnes, Agnes; Chiarello, Marlene; Faury, Nicole; Rubio, Tristan; Leroy, Marc; Perignon, Adeline; Regler, Denis; Morga, Benjamin; Alunno-bruscia, Marianne; Boudry, Pierre; Le Roux, Frederique; Destoumieux-garzon, Delphine; Gueguen, Yannick; Mitta, Guillaume.
Infectious diseases are mostly explored using reductionist approaches despite repeated evidence showing them to be strongly in fluenced by numerous interacting host and environmental factors. Many diseases with a complex aetiology therefore remain misunderstood. By developing a holistic approach to tackle the complexity of interactions, we decipher the complex intra-host interactions underlying Pacific oyster mortality syndrome affecting juveniles of Crassostrea gigas, the main oyster species exploited worldwide. Using experimental infections reproducing the natural route of infection and combining thorough molecular analyses of oyster families with contrasted susceptibilities, we demonstrate that the disease is caused by multiple infection with an initial...
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00461/57234/59228.pdf

Cecropins as a marker of Spodoptera frugiperda immunosuppression during entomopathogenic bacterial challenge
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Duvic, B.; Jouan, V.; Essa, N.; Girard, P-a; Pages, S.; Khattar, Z. Abi; Volkoff, N-a; Givaudan, A.; Destoumieux-garzon, Delphine; Escoubas, Jean-michel.
An antimicrobial peptide (AMP) of the cecropin family was isolated by HPLC from plasma of the insect pest, Spodoptera frugiperda. Its molecular mass is 3910.9 Da as determined by mass spectrometry. Thanks to the EST database Spodobase, we were able to describe 13 cDNAs encoding six different cecropins which belong to the sub-families CecA, CecB, CecC and CecD. The purified peptide identified as CecB1 was chemically synthesized (syCecB1). It was shown to be active against Gram-positive and Gram-negative bacteria as well as fungi. Two closely related entomopathogenic bacteria, Xenorhabdus nematophila F1 and Xenorhabdus mauleonii VC01(T) showed different susceptibility to syCecB1. Indeed, X. nematophila was sensitive to syCecB1 whereas X. mauleonii had a...
Tipo: Text
Palavras-chave: Humoral immunity; Innate immunity; Immunosuppression; Lepidopteran; Invertebrate.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00086/19728/17485.pdf

An intimate link between antimicrobial peptide sequence diversity and binding to essential components of bacterial membranes
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Schmitt, Paulina; Rosa, Rafael D.; Destoumieux-garzon, Delphine.
Antimicrobial peptides and proteins (AMPs) are widespread in the living kingdom. They are key effectors of defense reactions and mediators of competitions between organisms. They are often cationic and amphiphilic, which favors their interactions with the anionic membranes of microorganisms. Several AMP families do not directly alter membrane integrity but rather target conserved components of the bacterial membranes in a process that provides them with potent and specific antimicrobial activities. Thus, lipopolysaccharides (LPS), lipoteichoic acids (LTA) or the peptidoglycan precursor Lipid II are targeted by a broad series of AMPs. Studying the functional diversity of immune effectors tells us about the essential residues involved in AMP mechanism of...
Tipo: Text
Palavras-chave: Functional diversity; Defensin; Anti-lipopolysaccharide factor; Mechanism of action; Resistance.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00286/39710/38165.pdf

Species-specific mechanisms of cytotoxicity toward immune cells determine the successful outcome of Vibrio infections
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Rubio, Tristan; Oyanedel, Daniel; Labreuche, Yannick; Toulza, Eve; Luo, Xing; Bruto, Maxime; Chaparro, Cristian; Torres, Marta; De Lorgeril, Julien; Haffner, Philippe; Vidal-dupiol, Jeremie; Lagorce, Arnaud; Petton, Bruno; Mitta, Guillaume; Jacq, Annick; Le Roux, Frederique; Charriere, Guillaume; Destoumieux-garzon, Delphine.
Vibrio species cause infectious diseases in humans and animals, but they can also live as commensals within their host tissues. How Vibrio subverts the host defenses to mount a successful infection remains poorly understood, and this knowledge is critical for predicting and managing disease. Here, we have investigated the cellular and molecular mechanisms underpinning infection and colonization of 2 virulent Vibrio species in an ecologically relevant host model, oyster, to study interactions with marine Vibrio species. All Vibrio strains were recognized by the immune system, but only nonvirulent strains were controlled. We showed that virulent strains were cytotoxic to hemocytes, oyster immune cells. By analyzing host and bacterial transcriptional...
Tipo: Text
Palavras-chave: T6SS; Toxin; Dual RNA-seq; Cytolysis; Pathogenesis.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00507/61837/65900.pdf

The COVID-19 pandemic and global environmental change: emerging research needs
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Barouki, Robert; Kogevinas, Manolis; Audouze, Karine; Belesova, Kristine; Bergman, Ake; Birnbaum, Linda; Boekhold, Sandra; Denys, Sebastien; Desseille, Celine; Drakvik, Elina; Frumkin, Howard; Garric, Jeanne; Destoumieux-garzon, Delphine; Haines, Andrew; Huss, Anke; Jensen, Genon; Karakitsios, Spyros; Klanova, Jana; Koskela, Iida-maria; Laden, Francine; Marano, Francelyne; Franziska Matthies-wiesler, Eva; Morris, George; Nowacki, Julia; Paloniemi, Riikka; Pearce, Neil; Peters, Annette; Rekola, Aino; Sarigiannis, Denis; Šebková, Katerina; Slama, Remy; Staatsen, Brigit; Tonne, Cathryn; Vermeulen, Roel; Vineis, Paolo.
The outbreak of COVID-19 raised numerous questions on the interactions between the occurrence of new infections, the environment, climate and health. The European Union requested the H2020 HERA project which aims at setting priorities in research on environment, climate and health, to identify relevant research needs regarding Covid-19. The emergence and spread of SARS-CoV-2 appears to be related to urbanization, habitat destruction, live animal trade, intensive livestock farming and global travel. The contribution of climate and air pollution requires additional studies. Importantly, the severity of COVID-19 depends on the interactions between the viral infection, ageing and chronic diseases such as metabolic, respiratory and cardiovascular diseases and...
Tipo: Text
Palavras-chave: SARS-COV-2; Biodiversity; Urbanization; Climate; Chemicals; Transformational change.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00659/77146/78471.pdf

Expression, tissue localization and synergy of antimicrobial peptides and proteins in the immune response of the oyster Crassostrea gigas
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Schmitt, Paulina; De Lorgeril, Julien; Gueguen, Yannick; Destoumieux-garzon, Delphine; Bachere, Evelyne.
Diverse families of antimicrobial peptides and proteins have been described in oysters. We investigated here how antimicrobials are involved in the immune response against a pathogenic strain of Vibrio splendidus. Oyster antimicrobials were shown to display a wide variety of expression profiles in hemocyte populations and tissues. Oyster defensins are constitutively expressed in specific tissues such as mantle (Cg-Defm) or hemocytes (Cg-Defhs), while Cg-BPI is inducible and Cg-Prp appears down-regulated in hemocytes upon infection. The migratory behavior of hemocytes that express the different antimicrobials was found to be involved in the oyster response to a pathogenic Vibrio infection. Indeed, it contributes to colocalize several antimicrobials that...
Tipo: Text
Palavras-chave: Pacific oyster; Bivalve mollusk; Innate immunity; Bactericidal/permeability-increasing protein; Proline-rich peptide; Defensin; Vibrio.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00093/20382/18267.pdf

Big Defensins, a Diverse Family of Antimicrobial Peptides That Follows Different Patterns of Expression in Hemocytes of the Oyster Crassostrea gigas
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Rosa, Rafael D.; Santini, Adrien; Fievet, Julie; Bulet, Philippe; Destoumieux-garzon, Delphine; Bachere, Evelyne.
Background: Big defensin is an antimicrobial peptide composed of a highly hydrophobic N-terminal region and a cationic C-terminal region containing six cysteine residues involved in three internal disulfide bridges. While big defensin sequences have been reported in various mollusk species, few studies have been devoted to their sequence diversity, gene organization and their expression in response to microbial infections. Findings: Using the high-throughput Digital Gene Expression approach, we have identified in Crassostrea gigas oysters several sequences coding for big defensins induced in response to a Vibrio infection. We showed that the oyster big defensin family is composed of three members (named Cg-BigDef1, Cg-BigDef2 and Cg-BigDef3) that are...
Tipo: Text
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00050/16096/13576.pdf

Functional Divergence in Shrimp Anti-Lipopolysaccharide Factors (ALFs): From Recognition of Cell Wall Components to Antimicrobial Activity
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Rosa, Rafael Diego; Vergnes, Agnes; De Lorgeril, Julien; Goncalves, Priscila; Perazzolo, Luciane Maria; Saune, Laure; Romestand, Bernard; Fievet, Julie; Gueguen, Yannick; Bachere, Evelyne; Destoumieux-garzon, Delphine.
Antilipopolysaccharide factors (ALFs) have been described as highly cationic polypeptides with a broad spectrum of potent antimicrobial activities. In addition, ALFs have been shown to recognize LPS, a major component of the Gram-negative bacteria cell wall, through conserved amino acid residues exposed in the four-stranded beta-sheet of their three dimensional structure. In penaeid shrimp, ALFs form a diverse family of antimicrobial peptides composed by three main variants, classified as ALF Groups A to C. Here, we identified a novel group of ALFs in shrimp (Group D ALFs), which corresponds to anionic polypeptides in which many residues of the LPS binding site are lacking. Both Group B (cationic) and Group D (anionic) shrimp ALFs were produced in a...
Tipo: Text
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00160/27077/25236.pdf

Oyster Farming, Temperature, and Plankton Influence the Dynamics of Pathogenic Vibrios in the Thau Lagoon
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Lopez-joven, Maria-carmen; Rolland, Jean-luc; Haffner, Philippe; Caro, Audrey; Roques, Cecile; Carre, Claire; Travers, Marie-agnes; Abadie, Eric; Laabir, Mohamed; Bonnet, Delphine; Destoumieux-garzon, Delphine.
Vibrio species have been associated with recurrent mass mortalities of juvenile oysters Crassostrea gigas threatening oyster farming worldwide. However, knowledge of the ecology of pathogens in affected oyster farming areas remains scarce. Specifically, there are no data regarding (i) the environmental reservoirs of Vibrio populations pathogenic to oysters, (ii) the environmental factors favoring their transmission, and (iii) the influence of oyster farming on the persistence of those pathogens. This knowledge gap limits our capacity to predict and mitigate disease occurrence. To address these issues, we monitored Vibrio species potentially pathogenic to C. gigas in 2013 and 2014 in the Thau Lagoon, a major oyster farming region in the coastal French...
Tipo: Text
Palavras-chave: Vibrio; Shellfish farming; Bivalve mollusks; Mortality outbreak; Phytoplankton; Zooplankton.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00463/57479/59598.pdf

Class II Microcins
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Vassiliadis, Gaelle; Destoumieux-garzon, Delphine; Peduzzi, Jean.
Class II microcins are 4.9- to 8.9-kDa polypeptides produced by and active against enterobacteria. They are classified into two subfamilies according to their structure and their gene cluster arrangement. While class ha microcins undergo no posttranslational modification, class Jib rnicrocins show a conserved C-terminal sequence that carries a salmochelin-like siderophore motif as a posttranslational modification. Aside from this C-terminal end, which is the signature of class IIb microcins, some sequence similarities can be observed within and between class II subclasses, suggesting the existence of common ancestors. Their mechanisms of action are still under investigation, but several class II microcins use inner membrane proteins as cellular targets,...
Tipo: Text
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00073/18386/16447.pdf

Contribution of Viral Genomic Diversity to Oyster Susceptibility in the Pacific Oyster Mortality Syndrome
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Delmotte, Jean; Chaparro, Cristian; Galinier, Richard; De Lorgeril, Julien; Petton, Bruno; Stenger, Pierre-louis; Vidal-dupiol, Jeremie; Destoumieux-garzon, Delphine; Gueguen, Yannick; Montagnani, Caroline; Escoubas, Jean Michel; Mitta, Guillaume.
Juvenile Pacific oysters (Crassostrea gigas) are subjected to recurrent episodes of mass mortalities that constitute a threat for the oyster industry. This mortality syndrome named “Pacific Oyster Mortality Syndrome” (POMS) is a polymicrobial disease whose pathogenesis is initiated by a primary infection by a variant of an Ostreid herpes virus named OsHV-1 μVar. The characterization of the OsHV-1 genome during different disease outbreaks occurring in different geographic areas has revealed the existence of a genomic diversity for OsHV-1 μVar. However, the biological significance of this diversity is still poorly understood. To go further in understanding the consequences of OsHV-1 diversity on POMS, we challenged five biparental families of oysters to two...
Tipo: Text
Palavras-chave: Crassostrea gigas; Herpesvirus diversity; Genotype-genotype interactions; Oyster genetic background; Viral populations.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00643/75533/76414.pdf

Use of OmpU porins for attachment and invasion of Crassostrea gigas immune cells by the oyster pathogen Vibrio splendidus
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Duperthuy, Marylise; Schmitt, Paulina; Garzon, Edwin; Caro, Audrey; Rosa, Rafael D.; Le Roux, Frederique; Lautredou-audouy, Nicole; Got, Patrice; Romestand, Bernard; De Lorgeril, Julien; Kieffer-jaquinod, Sylvie; Bachere, Evelyne; Destoumieux-garzon, Delphine.
OmpU porins are increasingly recognized as key determinants of pathogenic host Vibrio interactions. Although mechanisms remain incompletely understood, various species, including the human pathogen Vibrio cholera, require OmpU for host colonization and virulence. We have shown previously that OmpU is essential for virulence in the oyster pathogen Vibrio splendidus LGP32. Here, we showed that V. splendidus LGP32 invades the oyster immune cells, the hemocytes, through subversion of host-cell actin cytoskeleton. In this process, OmpU serves as an adhesin/invasin required for beta-integrin recognition and host cell invasion. Furthermore, the major protein of oyster plasma, the extracellular superoxide dismutase Cg-EcSOD, is used as an opsonin mediating the...
Tipo: Text
Palavras-chave: Host-pathogen interaction; Innate immunity; Invertebrate; Mollusk; Oxidative burst.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00031/14177/12166.pdf

Antimicrobial histones and DNA traps in invertebrate immunity: evidences in Crassostrea gigas.
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Poirier, Aurore C.; Schmitt, Paulina; Rosa, Rafael D.; Vanhove, Audrey S.; Kieffer-jaquinod, Sylvie; Rubio, Tristan P.; Charriere, Guillaume M.; Destoumieux-garzon, Delphine.
Although antimicrobial histones have been isolated from multiple metazoan species, their role in host defense has long remained unanswered. We found here that the hemocytes of the oyster Crassostrea gigas release antimicrobial H1-like and H5-like histones in response to tissue damage and infection. These antimicrobial histones were shown to be associated with extracellular DNA networks released by hemocytes, the circulating immune cells of invertebrates, in response to immune challenge. The hemocyte-released DNA was found to surround and entangle vibrios. This defense mechanism is reminiscent of the neutrophil extracellular traps (ETs) recently described in vertebrates. Importantly, oyster ETs were evidenced in vivo in hemocyte-infiltrated interstitial...
Tipo: Text
Palavras-chave: Antimicrobial Peptide (AMP); DNA; Innate Immunity; Invertebrate; Reactive Oxygen Species (ROS); NET; Mollusk.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00217/32866/31784.pdf

Field enhanced bacterial sample stacking in isotachophoresis using wide-bore capillaries
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Oukacine, Farid; Quirino, Joselito P.; Destoumieux-garzon, Delphine; Cottet, Herve.
The isotachophoretic analysis of different bacterial strains was studied using capillaries with different internal diameters from 50 to 250 mu m. Several injection modes were investigated and compared in order to improve the limit of detection of bacteria by capillary isotachophoresis. A system suitability test obtained from the separation voltage was developed to ensure reliable results. As expected, the use of wider bore capillaries improved the analytical sensitivity of the isotachophoretic method when compared to the 50 mu m capillary. With the optimized conditions, the isotachophoretic method presented in this work allows the quantification of Erwinia carotovora (Gram negative bacteria) with a limit of detection as low as similar to 3000 cells mL(-1)....
Tipo: Text
Palavras-chave: Capillary zone electrophoresis; Isotachophoresis; Bacteria; Electrokinetic injection; Field-enhanced sample injection.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00115/22636/20596.pdf

The new insights into the oyster antimicrobial defense: Cellular, molecular and genetic view
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Bachere, Evelyne; Rosa, Rafael Diego; Schmitt, Paulina; Poirier, Aurore; Merou, Nicolas; Charriere, Guillaume; Destoumieux-garzon, Delphine.
Oysters are sessile filter feeders that live in close association with abundant and diverse communities of microorganisms that form the oyster microbiota. In such an association, cellular and molecular mechanisms have evolved to maintain oyster homeostasis upon stressful conditions including infection and changing environments. We give here cellular and molecular insights into the Crassostrea gigas antimicrobial defense system with focus on antimicrobial peptides and proteins (AMPs). This review highlights the central role of the hemocytes in the modulation and control of oyster antimicrobial response. As vehicles for AMPs and other antimicrobial effectors, including reactive oxygen species (ROS), and together with epithelia, hemocytes provide the oyster...
Tipo: Text
Palavras-chave: Mollusk; Immunity; Antimicrobial peptide; Hemocyte; Defensin.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00254/36552/35097.pdf

Inefficient immune response is associated with microbial permissiveness in juvenile oysters affected by mass mortalities on field
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: De Lorgeril, Julien; Escoubas, Jean Michel; Loubiere, Vincent; Pernet, Fabrice; Le Gall, Patrik; Vergnes, Agnes; Aujoulat, Fabien; Jeannot, Jean-luc; Jumas-bilak, Estelle; Got, Patrice; Gueguen, Yannick; Destoumieux-garzon, Delphine; Bachere, Evelyne.
Since 2008, juvenile Crassostrea gigas oysters have suffered from massive mortalities in European farming areas. This disease of complex etiology is still incompletely understood. Triggered by an elevated seawater temperature, it has been associated to infections by a herpes virus named OsHV-1 as well as pathogenic vibrios of the Splendidus clade. Ruling out the complexity of the disease, most of our current knowledge has been acquired in controlled experiments. Among the many unsolved questions, it is still ignored what role immunity plays in the capacity oysters have to survive an infectious episode. Here we show that juvenile oysters susceptible to the disease mount an inefficient immune response associated with microbial permissiveness and death. We...
Tipo: Text
Palavras-chave: Host pathogen interaction; Innate immunity; Invertebrate; Mollusk; In situ mortality; Total bacteria; Crassostrea gigas.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00433/54470/55845.pdf

A hemocyanin-derived antimicrobial peptide from the penaeid shrimp adopts an alpha-helical structure that specifically permeabilizes fungal membranes
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Petit, Vanessa W.; Rolland, Jean-luc; Blond, Alain; Cazevieille, Chantal; Djediat, Chakib; Peduzzi, Jean; Goulard, Christophe; Bachere, Evelyne; Dupont, Joelle; Destoumieux-garzon, Delphine; Rebuffat, Sylvie.
Background. Hemocyanins are respiratory proteins with multiple functions. In diverse crustaceans hemocyanins can release histidine-rich antimicrobial peptides in response to microbial challenge. In penaeid shrimp, strictly antifungal peptides are released from the C-terminus of hemocyanins.  Methods. The three-dimensional structure of the antifungal peptide PvHCt from Litopenaeus vannamei was determined by NMR. Its mechanism of action against the shrimp pathogen Fusarium oxysporum was investigated using immunochemistry, fluorescence and transmission electron microscopy.  Results. PvHCt folded into an amphipathic α-helix in membrane-mimicking media and displayed a random conformation in aqueous environment. In contact with F. oxysporum, PvHCt bound...
Tipo: Text
Palavras-chave: Antimicrobial peptide; Amphipathic helix; Fungi; Membrane bilayer; Nuclear magnetic resonance (NMR); Fluorescence microscopy.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00301/41202/40362.pdf

The One Health Concept: 10 Years Old and a Long Road Ahead
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Destoumieux-garzon, Delphine; Mavingui, Patrick; Boetsch, Gilles; Boissier, Jerome; Darriet, Frederic; Duboz, Priscilla; Fritsch, Clementine; Giraudoux, Patrick; Le Roux, Frederique; Morand, Serge; Paillard, Christine; Pontier, Dominique; Sueur, Cedric; Voituron, Yann.
Over the past decade, a significant increase in the circulation of infectious agents was observed. With the spread and emergence of epizootics, zoonoses, and epidemics, the risks of pandemics became more and more critical. Human and animal health has also been threatened by antimicrobial resistance, environmental pollution, and the development of multifactorial and chronic diseases. This highlighted the increasing globalization of health risks and the importance of the human–animal–ecosystem interface in the evolution and emergence of pathogens. A better knowledge of causes and consequences of certain human activities, lifestyles, and behaviors in ecosystems is crucial for a rigorous interpretation of disease dynamics and to drive public policies. As a...
Tipo: Text
Palavras-chave: One health; EcoHealth; Infectious disease; Non-communicable disease; Multifactorial disease; Ecotoxicology; Interdisciplinary research; Public health.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00425/53676/54518.pdf

A Sustained Immune Response Supports Long-Term Antiviral Immune Priming in the Pacific Oyster,  Crassostrea gigas
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Lafont, Maxime; Vergnes, Agnes; Vidal-dupiol, Jeremie; De Lorgeril, Julien; Gueguen, Yannick; Haffner, Philippe; Petton, Bruno; Chaparro, Cristian; Barrachina, Celia; Destoumieux-garzon, Delphine; Mitta, Guillaume; Gourbal, Benjamin; Montagnani, Caroline.
Over the last decade, innate immune priming has been evidenced in many invertebrate phyla. If mechanistic models have been proposed, molecular studies aiming to substantiate these models have remained scarce. We reveal here the transcriptional signature associated with immune priming in the oyster Crassostrea gigas. Oysters were fully protected against Ostreid herpesvirus 1 (OsHV-1), a major oyster pathogen, after priming with poly(I·C), which mimics viral double-stranded RNA. Global analysis through RNA sequencing of oyster and viral genes after immune priming and viral infection revealed that poly(I·C) induces a strong antiviral response that impairs OsHV-1 replication. Protection is based on a sustained upregulation of immune genes, notably genes...
Tipo: Text
Palavras-chave: Innate immunity; Priming; OsHV-1; Antiviral response; Immune memory; Oyster; POMS; Poly(I·C); Interferon; Transcriptomic.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00614/72580/71541.pdf

The paralytic shellfish toxin, saxitoxin, enters the cytoplasm and induces apoptosis of oyster immune cells through a caspase-dependent pathway
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Abikhalil, Celina; Finkelstein, Darren S.; Conejero, Genevieve; Du Bois, Justin; Destoumieux-garzon, Delphine; Rolland, Jean-luc.
Exposure of the toxin-producing dinoflagellate Alexandrium catenella (A. catenella) was previously demonstrated to cause apoptosis of hemocytes in the oyster species Crassostrea gigas. In this work, a coumarin-labeled saxitoxin appeared to spread throughout the cytoplasm of the hemocytes. PSTs, including saxitoxin, were also shown to be directly responsible for inducing apoptosis in hemocytes, a process dependent on caspase activation and independent of reactive oxygen species (ROS) production. A series of in vitro labeling and microscopy experiments revealed that STX and analogs there of induced nuclear condensation, phosphatidylserine exposure, membrane permeability, and DNA fragmentation of hemocytes. Unlike in vertebrates, gonyautoxin-5 (GTX5), which...
Tipo: Text
Palavras-chave: Shellfish; Toxin; Harmful algae; Phytoplankton.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00391/50272/50905.pdf

Insight into Invertebrate Defensin Mechanism of Action OYSTER DEFENSINS INHIBIT PEPTIDOGLYCAN BIOSYNTHESIS BY BINDING TO LIPID II
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Schmitt, Paulina; Wilmes, Miriam; Pugniere, Martine; Aumelas, Andre; Bachere, Evelyne; Sahl, Hans-georg; Schneider, Tanja; Destoumieux-garzon, Delphine.
Three oyster defensin variants (Cg-Defh1, Cg-Defh2, and Cg-Defm) were produced as recombinant peptides and characterized in terms of activities and mechanism of action. In agreement with their spectrum of activity almost specifically directed against Gram-positive bacteria, oyster defensins were shown here to be specific inhibitors of a bacterial biosynthesis pathway rather than mere membrane-active agents. Indeed, at lethal concentrations, the three defensins did not compromise Staphylococcus aureus membrane integrity but inhibited the cell wall biosynthesis as indicated by the accumulation of the UDP-N-acetylmuramyl-pentapeptide cell wall precursor. In addition, a combination of antagonization assays, thin layer chromatography, and surface plasmon...
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00014/12503/9369.pdf

The emergence of Vibrio pathogens in Europe: ecology, evolution, and pathogenesis (Paris, 11-12th March 2015)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Le Roux, Frederique; Wegner, K. Mathias; Baker-austin, Craig; Vezzulli, Luigi; Osorio, Carlos R.; Amaro, Carmen; Ritchie, Jennifer M.; Defoirdt, Tom; Destoumieux-garzon, Delphine; Blokesch, Melanie; Mazel, Didier; Jacq, Annick; Cava, Felipe; Gram, Lone; Wendling, Carolin C.; Strauch, Eckhard; Kirschner, Alexander; Huehn, Stephan.
Global change has caused a worldwide increase in reports of Vibrio-associated diseases with ecosystem-wide impacts on humans and marine animals. In Europe, higher prevalence of human infections followed regional climatic trends with outbreaks occurring during episodes of unusually warm weather. Similar patterns were also observed in Vibrio-associated diseases affecting marine organisms such as fish, bivalves and corals. Basic knowledge is still lacking on the ecology and evolutionary biology of these bacteria as well as on their virulence mechanisms. Current limitations in experimental systems to study infection and the lack of diagnostic tools still prevent a better understanding of Vibrio emergence. A major challenge is to foster cooperation between...
Tipo: Text
Palavras-chave: Global warming; Human health; Aquaculture; Interactions; Animal model; Bacterial disease; Genome plasticity; European network.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00278/38952/37494.pdf

Outer membrane vesicles are vehicles for the delivery of Vibrio tasmaniensis virulence factors to oyster immune cells
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Vanhove, Audrey; Duperthuy, Marylise; Charriere, Guillaume; Le Roux, Frederique; Goudenege, David; Gourbal, Benjamin; Kieffer-jaquinod, Sylvie; Coute, Yohann; Wai, Sun Nyunt; Destoumieux-garzon, Delphine.
Vibrio tasmaniensis LGP32, a facultative intracellular pathogen of oyster haemocytes, was shown here to release outer membrane vesicles (OMVs) both in the extracellular milieu and inside haemocytes. Intracellular release of OMVs occurred inside phagosomes of intact haemocytes having phagocytosed few vibrios as well as in damaged haemocytes containing large vacuoles heavily loaded with LGP32. The OMV proteome of LGP32 was shown to be rich in hydrolases (25%) including potential virulence factors such as proteases, lipases, phospholipases, haemolysins and nucleases. One major caseinase/gelatinase named Vsp for vesicular serine protease was found to be specifically secreted through OMVs in which it is enclosed. Vsp was shown to participate in the virulence...
Tipo: Text
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00199/31009/29459.pdf