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  1. Article ; Online: Moxifloxacin Activates the SOS Response in Mycobacterium tuberculosis in a Dose- and Time-Dependent Manner

    Angelo Iacobino / Giovanni Piccaro / Manuela Pardini / Lanfranco Fattorini / Federico Giannoni

    Microorganisms, Vol 9, Iss 2, p

    2021  Volume 255

    Abstract: Previous studies on Escherichia coli demonstrated that sub-minimum inhibitory concentration (MIC) of fluoroquinolones induced the SOS response, increasing drug tolerance. We characterized the transcriptional response to moxifloxacin in Mycobacterium ... ...

    Abstract Previous studies on Escherichia coli demonstrated that sub-minimum inhibitory concentration (MIC) of fluoroquinolones induced the SOS response, increasing drug tolerance. We characterized the transcriptional response to moxifloxacin in Mycobacterium tuberculosis . Reference strain H37Rv was treated with moxifloxacin and gene expression studied by qRT-PCR. Five SOS regulon genes, recA , lexA , dnaE2 , Rv3074 and Rv3776, were induced in a dose- and time-dependent manner. A range of moxifloxacin concentrations induced recA , with a peak observed at 2 × MIC (0.25 μg/mL) after 16 h. Another seven SOS responses and three DNA repair genes were significantly induced by moxifloxacin. Induction of recA by moxifloxacin was higher in log-phase than in early- and stationary-phase cells, and absent in dormant bacilli. Furthermore, in an H37Rv fluoroquinolone-resistant mutant carrying the D94G mutation in the gyrA gene, the SOS response was induced at drug concentrations higher than the mutant MIC value. The 2 × MIC of moxifloxacin determined no significant changes in gene expression in a panel of 32 genes, except for up-regulation of the relK toxin and of Rv3290c and Rv2517c , two persistence-related genes. Overall, our data show that activation of the SOS response by moxifloxacin, a likely link to increased mutation rate and persister formation, is time, dose, physiological state and, possibly, MIC dependent.
    Keywords Mycobacterium tuberculosis ; SOS response ; DNA repair ; fluoroquinolone ; moxifloxacin ; Biology (General) ; QH301-705.5
    Subject code 572
    Language English
    Publishing date 2021-01-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article: Mycobacterium tuberculosis gene expression at different stages of hypoxia-induced dormancy and upon resuscitation

    Iona, Elisabetta / Manuela Pardini / Alessandro Mustazzolu / Giovanni Piccaro / Roberto Nisini / Lanfranco Fattorini / Federico Giannoni

    journal of microbiology. 2016 Aug., v. 54, no. 8

    2016  

    Abstract: The physiology of dormant Mycobacterium tuberculosis was studied in detail by examining the gene expression of 51 genes using quantitative Reverse-Transcription Polymerase Chain Reaction. A forty-day period of dormancy in the Wayne culture model depicted ...

    Abstract The physiology of dormant Mycobacterium tuberculosis was studied in detail by examining the gene expression of 51 genes using quantitative Reverse-Transcription Polymerase Chain Reaction. A forty-day period of dormancy in the Wayne culture model depicted four major transcription patterns. Some sigma factors and many metabolic genes were constant, whereas genes belonging to the dormancy regulon were activated on day 9. In particular, alpha-crystallin mRNA showed more than a 1,000-fold increase compared to replicating bacilli. Genes belonging to the enduring hypoxic response were up-regulated at day 16, notably, transcription factors sigma B and E. Early genes typical of log-phase bacilli, esat-6 and fbpB, were uniformly down-regulated during dormancy. Late stages of dormancy showed a drop in gene expression likely due to a lack of substrates in anaerobic respiration as demonstrated by the transcriptional activation observed following nitrates addition. Among genes involved in nitrate metabolism, narG was strongly up-regulated by nitrates addition. Dormant bacilli responded very rapidly when exposed to oxygen and fresh medium, showing a transcriptional activation of many genes, including resuscitation-promoting factors, within one hour. Our observations extend the current knowledge on dormant M. tuberculosis gene expression and its response to nutrients and to aerobic and anaerobic respiration.
    Keywords Mycobacterium tuberculosis ; anaerobiosis ; dormancy ; gene expression ; messenger RNA ; models ; nitrates ; nutrients ; oxygen ; regulon ; reverse transcriptase polymerase chain reaction ; sigma factors ; transcriptional activation
    Language English
    Dates of publication 2016-08
    Size p. 565-572.
    Publishing place The Microbiological Society of Korea
    Document type Article
    ZDB-ID 2012399-1
    ISSN 1225-8873
    ISSN 1225-8873
    DOI 10.1007/s12275-016-6150-4
    Database NAL-Catalogue (AGRICOLA)

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  3. Article ; Online: Candida albicans Targets a Lipid Raft/Dectin-1 Platform to Enter Human Monocytes and Induce Antigen Specific T Cell Responses.

    Valeria de Turris / Raffaela Teloni / Paola Chiani / Carla Bromuro / Sabrina Mariotti / Manuela Pardini / Roberto Nisini / Antonella Torosantucci / Maria Cristina Gagliardi

    PLoS ONE, Vol 10, Iss 11, p e

    2015  Volume 0142531

    Abstract: Several pathogens have been described to enter host cells via cholesterol-enriched membrane lipid raft microdomains. We found that disruption of lipid rafts by the cholesterol-extracting agent methyl-β-cyclodextrin or by the cholesterol-binding ... ...

    Abstract Several pathogens have been described to enter host cells via cholesterol-enriched membrane lipid raft microdomains. We found that disruption of lipid rafts by the cholesterol-extracting agent methyl-β-cyclodextrin or by the cholesterol-binding antifungal drug Amphotericin B strongly impairs the uptake of the fungal pathogen Candida albicans by human monocytes, suggesting a role of raft microdomains in the phagocytosis of the fungus. Time lapse confocal imaging indicated that Dectin-1, the C-type lectin receptor that recognizes Candida albicans cell wall-associated β-glucan, is recruited to lipid rafts upon Candida albicans uptake by monocytes, supporting the notion that lipid rafts act as an entry platform. Interestingly disruption of lipid raft integrity and interference with fungus uptake do not alter cytokine production by monocytes in response to Candida albicans but drastically dampen fungus specific T cell response. In conclusion, these data suggest that monocyte lipid rafts play a crucial role in the innate and adaptive immune responses to Candida albicans in humans and highlight a new and unexpected immunomodulatory function of the antifungal drug Amphotericin B.
    Keywords Medicine ; R ; Science ; Q
    Language English
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Mycobacterium tuberculosis-induced miR-155 subverts autophagy by targeting ATG3 in human dendritic cells.

    Marilena P Etna / Alessandro Sinigaglia / Angela Grassi / Elena Giacomini / Alessandra Romagnoli / Manuela Pardini / Martina Severa / Melania Cruciani / Fabiana Rizzo / Eleni Anastasiadou / Barbara Di Camillo / Luisa Barzon / Gian Maria Fimia / Riccardo Manganelli / Eliana M Coccia

    PLoS Pathogens, Vol 14, Iss 1, p e

    2018  Volume 1006790

    Abstract: Autophagy is a primordial eukaryotic pathway, which provides the immune system with multiple mechanisms for the elimination of invading pathogens including Mycobacterium tuberculosis (Mtb). As a consequence, Mtb has evolved different strategies to hijack ...

    Abstract Autophagy is a primordial eukaryotic pathway, which provides the immune system with multiple mechanisms for the elimination of invading pathogens including Mycobacterium tuberculosis (Mtb). As a consequence, Mtb has evolved different strategies to hijack the autophagy process. Given the crucial role of human primary dendritic cells (DC) in host immunity control, we characterized Mtb-DC interplay by studying the contribution of cellular microRNAs (miRNAs) in the post-transcriptional regulation of autophagy related genes. From the expression profile of de-regulated miRNAs obtained in Mtb-infected human DC, we identified 7 miRNAs whose expression was previously found to be altered in specimens of TB patients. Among them, gene ontology analysis showed that miR-155, miR-155* and miR-146a target mRNAs with a significant enrichment in biological processes linked to autophagy. Interestingly, miR-155 was significantly stimulated by live and virulent Mtb and enriched in polysome-associated RNA fraction, where actively translated mRNAs reside. The putative pair interaction among the E2 conjugating enzyme involved in LC3-lipidation and autophagosome formation-ATG3-and miR-155 arose by target prediction analysis, was confirmed by both luciferase reporter assay and Atg3 immunoblotting analysis of miR-155-transfected DC, which showed also a consistent Atg3 protein and LC3 lipidated form reduction. Late in infection, when miR-155 expression peaked, both the level of Atg3 and the number of LC3 puncta per cell (autophagosomes) decreased dramatically. In accordance, miR-155 silencing rescued autophagosome number in Mtb infected DC and enhanced autolysosome fusion, thereby supporting a previously unidentified role of the miR-155 as inhibitor of ATG3 expression. Taken together, our findings suggest how Mtb can manipulate cellular miRNA expression to regulate Atg3 for its own survival, and highlight the importance to develop novel therapeutic strategies against tuberculosis that would boost autophagy.
    Keywords Immunologic diseases. Allergy ; RC581-607 ; Biology (General) ; QH301-705.5
    Subject code 500
    Language English
    Publishing date 2018-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: The M. tuberculosis Phosphate-Binding Lipoproteins PstS1 and PstS3 Induce Th1 and Th17 Responses That Are Not Associated with Protection against M. tuberculosis Infection

    Carla Palma / Ralf Spallek / Giovanni Piccaro / Manuela Pardini / Fatima Jonas / Wulf Oehlmann / Mahavir Singh / Antonio Cassone

    Clinical and Developmental Immunology, Vol

    2011  Volume 2011

    Abstract: The M. tuberculosis phosphate-binding transporter lipoproteins PstS1 and PstS3 were good immunogens inducing CD8+ T-cell activation and both Th1 and Th17 immunity in mice. However, this antigen-specific immunity, even when amplified by administration of ... ...

    Abstract The M. tuberculosis phosphate-binding transporter lipoproteins PstS1 and PstS3 were good immunogens inducing CD8+ T-cell activation and both Th1 and Th17 immunity in mice. However, this antigen-specific immunity, even when amplified by administration of the protein with the adjuvant LTK63 or by the DNA priming/protein boosting regimen, was not able to contain M. tuberculosis replication in the lungs of infected mice. The lack of protection might be ascribed with the scarce/absent capacity of PstS1/PstS3 antigens to modulate the IFN-γ response elicited by M. tuberculosis infection during which, however, PstS1-specific IL-17 secreting cells were generated in both unvaccinated and BCG-vaccinated mice. In spite of a lack of protection by PstS1/PstS3 immunizations, our results do show that PstS1 is able to induce IL-17 response upon M. tuberculosis infection which is of interest in the study of anti-M. tuberculosis immunity and as potential immunomodulator in combined vaccines.
    Keywords Medicine ; R ; Internal medicine ; RC31-1245 ; Specialties of internal medicine ; RC581-951 ; Immunologic diseases. Allergy ; RC581-607
    Subject code 570
    Language English
    Publishing date 2011-01-01T00:00:00Z
    Publisher Hindawi Publishing Corporation
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Expression of Proinflammatory and Regulatory Cytokines via NF-κB and MAPK-Dependent and IFN Regulatory Factor-3-Independent Mechanisms in Human Primary Monocytes Infected by Mycobacterium tuberculosis

    Elena Giacomini / Maria Elena Remoli / Marta Scandurra / Valérie Gafa / Manuela Pardini / Lanfranco Fattorini / Eliana M. Coccia

    Clinical and Developmental Immunology, Vol

    2011  Volume 2011

    Abstract: Knowledge of the molecular events regulating the innate response to Mycobacterium tuberculosis (Mtb) is critical for understanding immunological pathogenesis and protection from tuberculosis. To this aim, the regulation and the expression of regulatory ... ...

    Abstract Knowledge of the molecular events regulating the innate response to Mycobacterium tuberculosis (Mtb) is critical for understanding immunological pathogenesis and protection from tuberculosis. To this aim, the regulation and the expression of regulatory and proinflammatory cytokines were investigated in human primary monocytes upon Mtb infection. We found that Mtb-infected monocytes preferentially express a proinflammatory cytokine profile, including IL-6, TNF-α, and IL-1β. Conversely, among the regulatory cytokines, Mtb elicited IL-10 and IL-23 release while no expression of IL-12p70, IL-27, and IFN-β was observed. The analysis of the signalling pathways leading to this selective cytokine expression showed that in monocytes Mtb activates MAPK and NF-κB but is unable to stimulate IRF-3 phosphorylation, a transcription factor required for IL-12p35 and IFN-β gene expression. Thus, by inducing a specific cytokine profile, Mtb can influence the immunoregulatory properties of monocytes, which represent important target of novel vaccinal strategies against Mtb infection.
    Keywords Medicine ; R ; Internal medicine ; RC31-1245 ; Specialties of internal medicine ; RC581-951 ; Immunologic diseases. Allergy ; RC581-607
    Subject code 570
    Language English
    Publishing date 2011-01-01T00:00:00Z
    Publisher Hindawi Publishing Corporation
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Mycobacterium tuberculosis Drug Resistance, Abkhazia

    Manuela Pardini / Elisabetta Iona / Francis Varaine / Hayk Karakozian / Herchanik Arzumanian / Lara Brunori / Graziella Orefici / Lanfranco Fattorini

    Emerging Infectious Diseases, Vol 11, Iss 3, Pp 501-

    2005  Volume 503

    Keywords drug resistance ; Mycobacterium tuberculosis ; tuberculosis ; Abkhazia ; antituberculous agents ; letter ; Medicine ; R ; Infectious and parasitic diseases ; RC109-216
    Language English
    Publishing date 2005-03-01T00:00:00Z
    Publisher Centers for Disease Control and Prevention
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article ; Online: Treatment of tuberculosis in a region with high drug resistance

    Maryline Bonnet / Manuela Pardini / Francesca Meacci / Germano Orrù / Hasan Yesilkaya / Thierry Jarosz / Peter W Andrew / Mike Barer / Francesco Checchi / Heinz Rinder / Graziella Orefici / Sabine Rüsch-Gerdes / Lanfranco Fattorini / Marco Rinaldo Oggioni / Juliet Melzer / Stefan Niemann / Francis Varaine

    PLoS ONE, Vol 6, Iss 8, p e

    outcomes, drug resistance amplification and re-infection.

    2011  Volume 23081

    Abstract: Introduction Emerging antituberculosis drug resistance is a serious threat for tuberculosis (TB) control, especially in Eastern European countries. Methods We combined drug susceptibility results and molecular strain typing data with treatment outcome ... ...

    Abstract Introduction Emerging antituberculosis drug resistance is a serious threat for tuberculosis (TB) control, especially in Eastern European countries. Methods We combined drug susceptibility results and molecular strain typing data with treatment outcome reports to assess the influence of drug resistance on TB treatment outcomes in a prospective cohort of patients from Abkhazia (Georgia). Patients received individualized treatment regimens based on drug susceptibility testing (DST) results. Definitions for antituberculosis drug resistance and treatment outcomes were in line with current WHO recommendations. First and second line DST, and molecular typing were performed in a supranational laboratory for Mycobacterium tuberculosis (MTB) strains from consecutive sputum smear-positive TB patients at baseline and during treatment. Results At baseline, MTB strains were fully drug-susceptible in 189/326 (58.0%) of patients. Resistance to at least H or R (PDR-TB) and multidrug-resistance (MDR-TB) were found in 69/326 (21.2%) and 68/326 (20.9%) of strains, respectively. Three MDR-TB strains were also extensively resistant (XDR-TB). During treatment, 3/189 (1.6%) fully susceptible patients at baseline were re-infected with a MDR-TB strain and 2/58 (3.4%) PDR-TB patients became MDR-TB due to resistance amplification. 5/47 (10.6%) MDR- patients became XDR-TB during treatment. Treatment success was observed in 161/189 (85.2%), 54/69 (78.3%) and 22/68 (32.3%) of patients with fully drug susceptible, PDR- and MDR-TB, respectively. Development of ofloxacin resistance was significantly associated with a negative treatment outcome. Conclusion In Abkhazia, a region with high prevalence of drug resistant TB, the use of individualized MDR-TB treatment regimens resulted in poor treatment outcomes and XDR-TB amplification. Nosocomial transmission of MDR-TB emphasizes the importance of infection control in hospitals.
    Keywords Medicine ; R ; Science ; Q
    Language English
    Publishing date 2011-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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