Zika virus (ZIKV) is an emerging arbovirus of the Flaviviridae family, which includes dengue, West Nile, yellow fever, and Japanese encephalitis viruses, that causes a mosquito-borne disease ...transmitted by the Aedes genus, with recent outbreaks in the South Pacific. Here we examine the importance of human skin in the entry of ZIKV and its contribution to the induction of antiviral immune responses. We show that human dermal fibroblasts, epidermal keratinocytes, and immature dendritic cells are permissive to the most recent ZIKV isolate, responsible for the epidemic in French Polynesia. Several entry and/or adhesion factors, including DC-SIGN, AXL, Tyro3, and, to a lesser extent, TIM-1, permitted ZIKV entry, with a major role for the TAM receptor AXL. The ZIKV permissiveness of human skin fibroblasts was confirmed by the use of a neutralizing antibody and specific RNA silencing. ZIKV induced the transcription of Toll-like receptor 3 (TLR3), RIG-I, and MDA5, as well as several interferon-stimulated genes, including OAS2, ISG15, and MX1, characterized by strongly enhanced beta interferon gene expression. ZIKV was found to be sensitive to the antiviral effects of both type I and type II interferons. Finally, infection of skin fibroblasts resulted in the formation of autophagosomes, whose presence was associated with enhanced viral replication, as shown by the use of Torin 1, a chemical inducer of autophagy, and the specific autophagy inhibitor 3-methyladenine. The results presented herein permit us to gain further insight into the biology of ZIKV and to devise strategies aiming to interfere with the pathology caused by this emerging flavivirus.
Zika virus (ZIKV) is an arbovirus belonging to the Flaviviridae family. Vector-mediated transmission of ZIKV is initiated when a blood-feeding female Aedes mosquito injects the virus into the skin of its mammalian host, followed by infection of permissive cells via specific receptors. Indeed, skin immune cells, including dermal fibroblasts, epidermal keratinocytes, and immature dendritic cells, were all found to be permissive to ZIKV infection. The results also show a major role for the phosphatidylserine receptor AXL as a ZIKV entry receptor and for cellular autophagy in enhancing ZIKV replication in permissive cells. ZIKV replication leads to activation of an antiviral innate immune response and the production of type I interferons in infected cells. Taken together, these results provide the first general insights into the interaction between ZIKV and its mammalian host.
Introduction The Covid-19 pandemic has severely impacted the tourism sector with a 74% drop in international arrivals in 2020, and it went from bad to worse in early 2021, declining by 85% between ...January and May 2021 when compared to the same period of 2019, according to the latest data from the World Tourism Organisation (UNWTO). Destinations around the world welcomed 1 billion fewer international arrivals in 2020 than the previous year. While many efforts have been made to revive the secto...
Parasitism and ecosystems Thomas, Frédéric; Renaud, François; Guégan, Jean-François
2005, 2005-01-06
eBook, Book
Ecologists, epidemiologists, and evolutionary biologists are increasingly aware of the significance of parasites in the study of ecosystems. This book provides a summary of the issues involved as ...well as an overview of the possibilities offered by this research topic, using well-documented case-studies to illustrate the main trends and prospects in this area. This is the first book devoted to the comprehension of both the roles and consequences of pathogens in ecosystems.
La forme enfin trouvée ? Thomas, Frédéric
Contextes (Liège),
03/2021, Letnik:
30
Journal Article
Recenzirano
Odprti dostop
Dans son étude fondatrice, Les Écrivains contre la Commune, Paul Lidsky a brillamment analysé la réaction des auteurs les plus en vue de la période face à l’insurrection parisienne : presque tous s’y ...sont opposés avec virulence, ne laissant que des minores prendre parti pour les communards, et cette condamnation massive a contribué au retour à l’ordre après la Semaine sanglante. Pour autant, comme l’écrit Bertrand Tillier, le foisonnement discursif qui émerge dans le sillage de la répression ...
Cancer risk across mammals Vincze, Orsolya; Colchero, Fernando; Lemaître, Jean-Francois ...
Nature (London),
01/2022, Letnik:
601, Številka:
7892
Journal Article
Recenzirano
Odprti dostop
Cancer is a ubiquitous disease of metazoans, predicted to disproportionately affect larger, long-lived organisms owing to their greater number of cell divisions, and thus increased probability of ...somatic mutations
. While elevated cancer risk with larger body size and/or longevity has been documented within species
, Peto's paradox indicates the apparent lack of such an association among taxa
. Yet, unequivocal empirical evidence for Peto's paradox is lacking, stemming from the difficulty of estimating cancer risk in non-model species. Here we build and analyse a database on cancer-related mortality using data on adult zoo mammals (110,148 individuals, 191 species) and map age-controlled cancer mortality to the mammalian tree of life. We demonstrate the universality and high frequency of oncogenic phenomena in mammals and reveal substantial differences in cancer mortality across major mammalian orders. We show that the phylogenetic distribution of cancer mortality is associated with diet, with carnivorous mammals (especially mammal-consuming ones) facing the highest cancer-related mortality. Moreover, we provide unequivocal evidence for the body size and longevity components of Peto's paradox by showing that cancer mortality risk is largely independent of both body mass and adult life expectancy across species. These results highlight the key role of life-history evolution in shaping cancer resistance and provide major advancements in the quest for natural anticancer defences.
Antimicrobial resistance in wildlife Vittecoq, Marion; Godreuil, Sylvain; Prugnolle, Franck ...
The Journal of applied ecology,
April 2016, Letnik:
53, Številka:
2
Journal Article
Recenzirano
Odprti dostop
1. The spread of antimicrobial resistance is of major concern for human health and leads to growing economic costs. While it is increasingly hypothesized that wildlife could play an important role in ...antimicrobial-resistant bacteria dynamics, empirical data remain scarce. 2. The present work builds on a systematic review of the available data in order to highlight the main information we have and to suggest research pathways that should be followed if we aim to fill the gaps in our current knowledge. 3. To achieve this goal, we address four questions: (i) Which resistant bacteria are the most frequently observed in wildlife? (ii) How are resistant bacteria exchanged between wildlife and the other hosts involved? (iii) In which habitats are those resistant bacteria found? (iv) Are resistances associated with certain ecological traits of the host? 4. Synthesis and applications. We highlight the strong link existing between the impact of human activities on natural habitats and the carriage of antimicrobial-resistant bacteria by wildlife. Furthermore, we underline that omnivorous, anthropophilic and carnivorous species are at high risk of being carriers and potentially spreaders of antimicrobial-resistant bacteria. Identifying among those groups key sentinel species may be of particular interest to implement ecosystem contamination surveillance. Finally, we discuss possible exchange routes for antimicrobial-resistant bacteria between humans and wildlife. Considering that water is of major importance in those exchanges, a critical way to control antimicrobial resistance spread may be to limit aquatic environment contamination by antimicrobial-resistant bacteria and antibiotics.
The ecological significance of manipulative parasites Lefèvre, Thierry; Lebarbenchon, Camille; Gauthier-Clerc, Michel ...
Trends in ecology & evolution (Amsterdam),
2009, 2009-Jan, 2009-1-00, 20090101, 2009-01, Letnik:
24, Številka:
1
Journal Article
Recenzirano
The diversity of ways in which host manipulation by parasites interferes with ecological and evolutionary processes governing biotic interactions has been recently documented, and indicates that ...manipulative parasites are full participants in the functioning of ecosystems. Phenotypic alterations in parasitised hosts modify host population ecology, apparent competition processes, food web structure and energy and nutrient flow between habitats, as well as favouring habitat creation. As is usually the case in ecology, these phenomena can be greatly amplified by a series of secondary consequences (cascade effects). Here we review the ecological relevance of manipulative parasites in ecosystems and propose directions for further research.
The characterization of circulating tumor cells (CTCs) holds promises for precision medicine because these cells are an important clinical indicator of treatment efficacy. We established the first ...and still only nine permanent colon CTC lines from peripheral blood samples of a patient with metastatic colon cancer collected at different time points during treatment and cancer progression. The study objectives were (i) to compare the gene expression profiles of these CTC lines, and (ii) to determine the main features acquired during treatment. The number of upregulated genes was higher in the CTC lines obtained after treatment, indicating that they acquired properties to escape treatment pressure. Among these upregulated genes, some are involved in the mTOR and PI3K/AKT signaling pathways. Moreover, cytidine deaminase expression was significantly increased in the CTC lines obtained after failure of the first- and second-line 5-fluorouracile-based treatments, suggesting that these CTCs can eliminate this specific drug and resist to therapy. Several enzymes involved in xenobiotic metabolism also were upregulated after treatment, suggesting the activation of detoxification mechanisms in response to chemotherapy. Finally, the significant higher expression of aldolase B in four of the six CTC lines obtained after treatment withdrawal and cancer progression indicated that these clones originated from liver metastases. In conclusion, these CTC lines generated at different time points during treatment of metastatic colon cancer in a single patient are characterized by the deregulation of different genes that promote (i) drug resistance, (ii) xenobiotic and energy metabolism, and (iii) stem cell properties and plasticity.
REVIEW: Antimicrobial resistance in wildlife Vittecoq, Marion; Godreuil, Sylvain; Prugnolle, Franck ...
The Journal of applied ecology,
04/2016, Letnik:
53, Številka:
2
Journal Article
Recenzirano
The spread of antimicrobial resistance is of major concern for human health and leads to growing economic costs. While it is increasingly hypothesized that wildlife could play an important role in ...antimicrobial‐resistant bacteria dynamics, empirical data remain scarce. The present work builds on a systematic review of the available data in order to highlight the main information we have and to suggest research pathways that should be followed if we aim to fill the gaps in our current knowledge. To achieve this goal, we address four questions: (i) Which resistant bacteria are the most frequently observed in wildlife? (ii) How are resistant bacteria exchanged between wildlife and the other hosts involved? (iii) In which habitats are those resistant bacteria found? (iv) Are resistances associated with certain ecological traits of the host? Synthesis and applications. We highlight the strong link existing between the impact of human activities on natural habitats and the carriage of antimicrobial‐resistant bacteria by wildlife. Furthermore, we underline that omnivorous, anthropophilic and carnivorous species are at high risk of being carriers and potentially spreaders of antimicrobial‐resistant bacteria. Identifying among those groups key sentinel species may be of particular interest to implement ecosystem contamination surveillance. Finally, we discuss possible exchange routes for antimicrobial‐resistant bacteria between humans and wildlife. Considering that water is of major importance in those exchanges, a critical way to control antimicrobial resistance spread may be to limit aquatic environment contamination by antimicrobial‐resistant bacteria and antibiotics.
Do malignant cells sleep at night? Cortés-Hernández, Luis Enrique; Eslami-S, Zahra; Dujon, Antoine M ...
Genome Biology,
11/2020, Letnik:
21, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Biological rhythms regulate the biology of most, if not all living creatures, from whole organisms to their constitutive cells, their microbiota, and also parasites. Here, we present the hypothesis ...that internal and external ecological variations induced by biological cycles also influence or are exploited by cancer cells, especially by circulating tumor cells, the key players in the metastatic cascade. We then discuss the possible clinical implications of the effect of biological cycles on cancer progression, and how they could be exploited to improve and standardize methods used in the liquid biopsy field.
PDF
