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See detailHTLV-1 clonality during chronic infection and BLV clonality during primary infection
Gillet, N.; Hlela, C.; Verdonck, T. et al

in AIDS Research and Human Retroviruses (2011, June 06), 8(1), 185

HTLV-1 clonality during chronic infection and BLV clonality during primary infection Nicolas A Gillet1,2*, Carol Hlela1, Tine Verdonck3, Eduardo Gotuzzo3, Daniel Clark3, Sabrina Rodriguez2, Nirav Malani4 ... [more ▼]

HTLV-1 clonality during chronic infection and BLV clonality during primary infection Nicolas A Gillet1,2*, Carol Hlela1, Tine Verdonck3, Eduardo Gotuzzo3, Daniel Clark3, Sabrina Rodriguez2, Nirav Malani4, Anat Melamed1, Niall Gormley5, Richard Carter5, David Bentley5, Charles Berry6, Frederic D Bushman4, Graham P Taylor7, Luc Willems2, Charles R M Bangham1 1Department of Immunology, Wright-Fleming Institute, Imperial College London, London, W2 1PG, UK. 2Molecular and Cellular Epigenetics, Interdisciplinary Cluster for Applied Genoproteomics (GIGA) of University of Liège (ULg), Liège, 4000, Belgium. 3Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru. 4Department of Microbiology, University of Pennsylvania School of Medicine, Pennsylvania, Philadelphia, PA, 19104, USA. 5Illumina, Chesterford Research Park, Essex, Little Chesterford, CB10 1XL, UK. 6University of California, California, La Jolla San Diego, CA, 92093-0901, USA. 7Department of Genitourinary Medicine and Communicable Diseases, Wright-Fleming Institute, Imperial College London, London, W2 1PG, UK. HTLV-1 persists by driving clonal proliferation of infected T-lymphocytes. A high proviral load predisposes to the inflammatory and malignant diseases associated with HTLV-1. Yet the reasons for the remarkable variation within and between individuals in the abundance of HTLV-1-infected clones remain unknown. We demonstrate that negative selection dominates during chronic infection, favouring establishment of proviruses integrated in transcriptionally silenced DNA: this selection is significantly stronger in asymptomatic carriers. We postulated that this selection occurred mainly during the primary infection. We are testing this hypothesis in an animal model by studying the BLV clonality during the primary infection in cows. By measuring the proviral load, the anti-BLV immune response and the BLV clonality we aim to quantify the impact of the immune response on the rate of infectious spread and on the selection of proviruses inserted in a particular genomic environment. Co-infection with Strongyloides stercoralis or Staphylococcus appears to be another risk factor for the development of HTLV-1 associated diseases. We observed that HTLV-1 clonality is altered by co-infection with these pathogens with an increase of both the number and the abundance of the infected T-cell clones. The genomic characteristics of the proviral integration sites in the most abundant clones differ significantly between co-infected individuals and those with HTLV-1 alone, implying the existence of different selection forces in co-infected patients. The rate of appearance of new clones in patients co-infected with Strongyloides stercoralis is higher than in patients with HTLV-1 alone. By comparing skin lesions and blood samples from patients with Infective Dermatitis associated with HTLV-1 (IDH), we observed a significant proportion of distinct infected clones between the two compartments. The skin lesions seem to be a site for HTLV-1 infectious spread. [less ▲]

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See detailHTLV-1 positive and negative T cells cloned from infected individuals display telomerase and telomere genes deregulation that predominate in activated but untransformed CD4+ T cells.
Zane, Linda; Sibon, David; CAPRARO, Valérie ULg et al

in International Journal of Cancer = Journal International du Cancer (2012), 131(4), 821-33

Untransformed HTLV-1 positive CD4(+) cells from infected individuals are selected for expressing tax and displaying morphological features consistent with telomere dysfunctions. We show that in resting ... [more ▼]

Untransformed HTLV-1 positive CD4(+) cells from infected individuals are selected for expressing tax and displaying morphological features consistent with telomere dysfunctions. We show that in resting HTLV-1 positive CD4(+) cells cloned from patients, hTERT expression parallels tax expression and cell cycling. Upon activation, these cells dramatically augment tax expression, whereas their increase in telomerase activity is about 20 times lower than that of their uninfected counterpart. Activated HTLV-1 positive CD4(+) but not uninfected CD4(+) or CD8(+) clones also repress the transcription of TRF1, TPP1, TANK1, POT1, DNA-PKc and Ku80. Both infected and uninfected lymphocytes from infected individuals shared common telomere gene deregulations toward a pattern consistent with premature senescence. ATLL cells displayed the highest telomerase activity (TA) whereas recovered a telomere gene transcriptome close to that of normal CD4(+) cells. In conclusion HTLV-1-dependent telomere modulations seem involved in clonal expansion, immunosuppression, tumor initiation and progression. [less ▲]

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See detailHTLV-1 propels thymic human T cell development in "human immune system" Rag2(-)/(-) gamma c(-)/(-) mice.
Villaudy, Julien; Wencker, Melanie; Gadot, Nicolas et al

in PLoS Pathogens (2011), 7(9), 1002231

Alteration of early haematopoietic development is thought to be responsible for the onset of immature leukemias and lymphomas. We have previously demonstrated that Tax(HTLV-1) interferes with ss-selection ... [more ▼]

Alteration of early haematopoietic development is thought to be responsible for the onset of immature leukemias and lymphomas. We have previously demonstrated that Tax(HTLV-1) interferes with ss-selection, an important checkpoint of early thymopoiesis, indicating that human T-cell leukemia virus type 1 (HTLV-1) infection has the potential to perturb thymic human alphabeta T-cell development. To verify that inference and to clarify the impact of HTLV-1 infection on human T-cell development, we investigated the in vivo effects of HTLV-1 infection in a "Human Immune System" (HIS) Rag2(-)/(-)gamma(c)(-)/(-) mouse model. These mice were infected with HTLV-1, at a time when the three main subpopulations of human thymocytes have been detected. In all but two inoculated mice, the HTLV-1 provirus was found integrated in thymocytes; the proviral load increased with the length of the infection period. In the HTLV-1-infected mice we observed alterations in human T-cell development, the extent of which correlated with the proviral load. Thus, in the thymus of HTLV-1-infected HIS Rag2(-)/(-)gammac(-)/(-) mice, mature single-positive (SP) CD4(+) and CD8(+) cells were most numerous, at the expense of immature and double-positive (DP) thymocytes. These SP cells also accumulated in the spleen. Human lymphocytes from thymus and spleen were activated, as shown by the expression of CD25: this activation was correlated with the presence of tax mRNA and with increased expression of NF-kB dependent genes such as bfl-1, an anti-apoptotic gene, in thymocytes. Finally, hepato-splenomegaly, lymphadenopathy and lymphoma/thymoma, in which Tax was detected, were observed in HTLV-1-infected mice, several months after HTLV-1 infection. These results demonstrate the potential of the HIS Rag2(-)/(-)gamma(c)(-)/(-) animal model to elucidate the initial steps of the leukemogenic process induced by HTLV-1. [less ▲]

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See detailThe HTLV-1 Tax interactome.
Boxus, Mathieu ULg; Twizere, Jean-Claude ULg; Legros, Sebastien et al

in Retrovirology (2008), 5

The Tax1 oncoprotein encoded by Human T-lymphotropic virus type I is a major determinant of viral persistence and pathogenesis. Tax1 affects a wide variety of cellular signalling pathways leading to ... [more ▼]

The Tax1 oncoprotein encoded by Human T-lymphotropic virus type I is a major determinant of viral persistence and pathogenesis. Tax1 affects a wide variety of cellular signalling pathways leading to transcriptional activation, proliferation and ultimately transformation. To carry out these functions, Tax1 interacts with and modulates activity of a number of cellular proteins. In this review, we summarize the present knowledge of the Tax1 interactome and propose a rationale for the broad range of cellular proteins identified so far. [less ▲]

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See detailThe HTLV-1 Tax protein inhibits formation of stress granules by interacting with histone deacetylase 6.
Legros, S.; Boxus, Mathieu ULg; Gatot, J. S. et al

in Oncogene (2011)

Human T cell leukemia virus type-1 (HTLV-1) is the causative agent of a fatal adult T-cell leukemia. Through deregulation of multiple cellular signaling pathways the viral Tax protein has a pivotal role ... [more ▼]

Human T cell leukemia virus type-1 (HTLV-1) is the causative agent of a fatal adult T-cell leukemia. Through deregulation of multiple cellular signaling pathways the viral Tax protein has a pivotal role in T-cell transformation. In response to stressful stimuli, cells mount a cellular stress response to limit the damage that environmental forces inflict on DNA or proteins. During stress response, cells postpone the translation of most cellular mRNAs, which are gathered into cytoplasmic mRNA-silencing foci called stress granules (SGs) and allocate their available resources towards the production of dedicated stress-management proteins. Here we demonstrate that Tax controls the formation of SGs and interferes with the cellular stress response pathway. In agreement with previous reports, we observed that Tax relocates from the nucleus to the cytoplasm in response to environmental stress. We found that the presence of Tax in the cytoplasm of stressed cells prevents the formation of SGs and counteracts the shutoff of specific host proteins. Unexpectedly, nuclear localization of Tax promotes spontaneous aggregation of SGs, even in the absence of stress. Mutant analysis revealed that the SG inhibitory capacity of Tax is independent of its transcriptional abilities but relies on its interaction with histone deacetylase 6, a critical component of SGs. Importantly, the stress-protective effect of Tax was also observed in the context of HTLV-1 infected cells, which were shown to be less prone to form SGs and undergo apoptosis under arsenite exposure. These observations identify Tax as the first virally encoded inhibitory component of SGs and unravel a new strategy developed by HTLV-1 to deregulate normal cell processes. We postulate that inhibition of the stress response pathway by Tax would favor cell survival under stressful conditions and may have an important role in HTLV-1-induced cellular transformation.Oncogene advance online publication, 2 May 2011; doi:10.1038/onc.2011.120. [less ▲]

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See detailHu, Luojia , Estimation of a censored dynamic panel data model,Econometrica. Journal of the Econometric Society
Rochus, Pierre ULg

in Mathematical Reviews [=MR] (2002), 70(6), 2499--2517

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See detailHubble observations of Jupiter’s north–south conjugate ultraviolet aurora
Gérard, Jean-Claude ULg; Grodent, Denis ULg; Radioti, Aikaterini ULg et al

in Icarus (2013), 226

Comparisons of the northern and southern far ultraviolet (UV) auroral emissions of Jupiter from the Hubble Space Telescope (HST) or any other ultraviolet imager have mostly been made so far on a ... [more ▼]

Comparisons of the northern and southern far ultraviolet (UV) auroral emissions of Jupiter from the Hubble Space Telescope (HST) or any other ultraviolet imager have mostly been made so far on a statistical basis or were not obtained with high sensitivity and resolution. Such observations are important to discriminate between different mechanisms responsible for the electron acceleration of the different components of the aurora such as the satellite footprints, the «main oval» or the polar emissions. The field of view of the ACS and STIS cameras on board HST is not wide enough to provide images of the full jovian disk. We thus compare the morphology of the north and south aurora observed 55 min apart and we point out similarities and differences. On one occasion HST pointed successively the two polar regions and auroral images were seen separated by only 3 min. This makes it possible to compare the emission structure and the emitted FUV power of corresponding regions. We find that most morphological features identified in one hemisphere have a conjugate counterpart in the other hemisphere. However, the power associated with conjugate regions of the main oval, diffuse or discrete equatoward emission observed quasi-simultaneously may be different in the two hemispheres. It is not directly nor inversely proportional to the strength of the B-field as one might expect for diffuse precipitation or field-aligned acceleration with equal ionospheric electron density in both hemispheres. Finally, the lack of symmetry of some polar emissions suggests that some of them could be located on open magnetic field lines. [less ▲]

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See detailHubble sans COSTAR
Grodent, Denis ULg; Dols, Vincent

Scientific conference (1994, June 23)

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See detailHubble Space Telescope far-ultraviolet imaging of Jupiter during the impacts of Comet Shoemaker-Levy 9
Clarke, J. T.; Prange, R.; Ballester, G. E. et al

in Highlights of Astronomy, Vol. 10 (1995)

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See detailHubble Space Telescope Goddard high-resolution spectrograph H2 rotational spectra of Jupiter's aurora
Clarke, John T; Ben Jaffel, Lotfi; Vidal-Madjar, Alfred et al

in Astrophysical Journal (1994), 430

We have observed the emission spectrum from Jupiter's north auroral atmosphere with 0.57 A spectral resolution over 1204-1241 A. Bright emissions have been detected from 50 deg to 60 deg latitude at ... [more ▼]

We have observed the emission spectrum from Jupiter's north auroral atmosphere with 0.57 A spectral resolution over 1204-1241 A. Bright emissions have been detected from 50 deg to 60 deg latitude at locations consistent with 6 to 30 R [SUB]J[/SUB] auroral ovals, with much fainter emissions away form the auroral ovals. The emission spectrum is well fitted by both laboratory spectra and theoretical models of optically thin electron excited H2, with added Doppler-broadened Lyman Alpha emission. The observed Lyman Alpha emission wings extend more than 1 A from line center and appear correlated in strength with the H2 brightness. Individual rotational lines in the H2 Werner band system are resolved, allowing a determination of the H2 rotational temperature at the altitude of the emission. We derive best-fit temperatures from 400-450 to 700-750 K, with the auroral emission layer temperature changing either across the auroral oval or over several days' time. These observations demonstrate for the first time the ability to measure the observed rapid H2 temperature variations across Jupiter's auroral atmosphere. [less ▲]

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See detailHubble Space Telescope imaging of Jupiter's UV aurora during the Galileo orbiter mission
Clarke, John T; Ben Jaffel, Lotfi; Gérard, Jean-Claude ULg

in Journal of Geophysical Research (1998), 103

Hubble Space Telescope (HST) Wide-Field Planetary Camera 2 (WFPC 2) images of Jupiter's aurora have been obtained close in time with Galileo ultraviolet spectrometer (UVS) spectra and in situ particles ... [more ▼]

Hubble Space Telescope (HST) Wide-Field Planetary Camera 2 (WFPC 2) images of Jupiter's aurora have been obtained close in time with Galileo ultraviolet spectrometer (UVS) spectra and in situ particles, fields, and plasma wave measurements between June 1996 and July 1997, overlapping Galileo orbits G1, G2, G7, G8, and C9. This paper presents HST images of Jupiter's aurora as a first step toward a comparative analysis of the auroral images with the in situ Galileo data. The WFPC 2 images appear similar to earlier auroral images, with the main ovals at similar locations to those observed over the preceding 2 years, and rapidly variable emissions poleward of the main ovals. Further examples have been observed of the equatorward surge of the auroral oval over 140-180° longitude as this region moves from local morning to afternoon. Comparison of the WFPC 2 reference auroral ovals north and south with the VIP4 planetary magnetic field model suggests that the main ovals map along magnetic field lines exceeding 15R[SUB]J[/SUB], and that the Io footprint locations have lead angles of 0-10° from the instantaneous magnetic projection. There was an apparent dawn auroral storm on June 23, 1996, and projections of the three dawn storms imaged with HST to date demonstrate that these appear consistently along the WFPC 2 reference oval. Auroral emissions have been consistently observed from Io's magnetic footprints on Jupiter. Possible systematic variations in brightness are explored, within factor of 6 variations in brightness with time. Images are also presented marked with expected locations of any auroral footprints associated with the satellites Europa and Ganymede, with localized emissions observed at some times but not at other times. [less ▲]

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See detailHubble Space Telescope/Advanced Camera for Surveys Observations of Europa's Atmospheric Ultraviolet Emission at Eastern Elongation
Saur, Joachim; Feldman, Paul D; Roth, Lorenz et al

in Astrophysical Journal (2011), 738

We report results of a Hubble Space Telescope (HST) campaign with the Advanced Camera for Surveys to observe Europa at eastern elongation, i.e., Europa's leading side, on 2008 June 29. With five ... [more ▼]

We report results of a Hubble Space Telescope (HST) campaign with the Advanced Camera for Surveys to observe Europa at eastern elongation, i.e., Europa's leading side, on 2008 June 29. With five consecutive HST orbits, we constrain Europa's atmospheric O I 1304 Å and O I 1356 Å emissions using the prism PR130L. The total emissions of both oxygen multiplets range between 132 ± 14 and 226 ± 14 Rayleigh. An additional systematic error with values on the same order as the statistical errors may be due to uncertainties in modeling the reflected light from Europa's surface. The total emission also shows a clear dependence of Europa's position with respect to Jupiter's magnetospheric plasma sheet. We derive a lower limit for the O[SUB]2[/SUB] column density of 6 × 10[SUP]18[/SUP] m[SUP]-2[/SUP]. Previous observations of Europa's atmosphere with the Space Telescope Imaging Spectrograph in 1999 of Europa's trailing side show an enigmatic surplus of radiation on the anti-Jovian side within the disk of Europa. With emission from a radially symmetric atmosphere as a reference, we searched for an anti-Jovian versus sub-Jovian asymmetry with respect to the central meridian on the leading side and found none. Likewise, we searched for departures from a radially symmetric atmospheric emission and found an emission surplus centered around 90° west longitude, for which plausible mechanisms exist. Previous work about the possibility of plumes on Europa due to tidally driven shear heating found longitudes with strongest local strain rates which might be consistent with the longitudes of maximum UV emissions. Alternatively, asymmetries in Europa's UV emission can also be caused by inhomogeneous surface properties, an optically thick atmospheric contribution of atomic oxygen, and/or by Europa's complex plasma interaction with Jupiter's magnetosphere. [less ▲]

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See detailHUBERT SUMLIN Portrait/Interview
Sacré, Robert ULg

Article for general public (1976)

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See detailHubert Juin
Stienon, Valérie ULg

in Blanchaud, Corinne (Ed.) Dictionnaire des écrivains francophones classiques. Belgique, Canada, Québec, Luxembourg, Suisse romande (2013)

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See detailHubert Juin
Stienon, Valérie ULg

in Mathis-Moser, Ursula; MERTZ-BAUMGARTNER, Birgit (Eds.) Passages et ancrages en France. Dictionnaire des écrivains migrants de langue française (1981-2011) (2012)

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See detailHubert Nyssen
Durand, Pascal ULg

in Mathis-Moser, Ursula; Mertz-Baumgartner, Birgit (Eds.) Passages et ancrages. Dictionnaire des écrivains migrants en France (1981-2011) (2012)

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See detailHubert Nyssen : d’un arbre à l’autre
Durand, Pascal ULg

in Carnet et les Instants (2005), 137

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See detailHubert Nyssen, Du Texte au Livre, les avatars du sens : entre accastillage et orchestration
Durand, Pascal ULg

Conference (2012, June)

Examen du point de vue pris par Hubert Nyssen, à la fois écrivain et éditeur, sur la question du paratexte éditorial, comparativement au point de vue de Gérard Genette sur cette même question. Description ... [more ▼]

Examen du point de vue pris par Hubert Nyssen, à la fois écrivain et éditeur, sur la question du paratexte éditorial, comparativement au point de vue de Gérard Genette sur cette même question. Description des forces formatrices de ce point de vue singulier pris sur l'« accastillage » du texte, de l'avant-texte à la promotion médiatique. [less ▲]

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See detailHubert Nyssen, écrivain et fondateur des éditions Actes Sud
Durand, Pascal ULg; Chambon, Jacqueline; Manguel, Alberto

Speech (2012)

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