References of "Piette, Jacques"
     in
Bookmark and Share    
See detailVaricella-zoster gene 63 encoded protein is an important regulatory factor
Jackers, Pascale ULg; Defechereux, Patricia; Baudoux, Laurence et al

in Archives Internationales de Physiologie, de Biochimie et de Biophysique (1992), 100

Detailed reference viewed: 24 (8 ULg)
See detailHIV-1 reactivation after an oxidative stress
Legrand, Sylvie ULg; Vaira, Dolorès ULg; Rentier, Bernard ULg et al

in LinkVIII International Conference on AIDS/III STD World Congress, Amsterdam, the Netherlands 19-24 July 1992 (1992)

OBJECTIVES: A common denominator shared by several HIV-1 reactivation agents such as certain cytokines, UV irradiation and heat shock is their ability to cause stress response. Consequently, we have ... [more ▼]

OBJECTIVES: A common denominator shared by several HIV-1 reactivation agents such as certain cytokines, UV irradiation and heat shock is their ability to cause stress response. Consequently, we have investigated the effects of oxidative stress on HIV-1 reactivation, knowing that HIV-1 latently infected T cells can be exposed in vivo to such a stress when blood phagocytes are stimulated during inflammatory reactions. METHODS: The promonocytic (U1) and lymphocytic (ACH-2) cell lines, both HIV-1 chronically infected, were used to study the reactivation phenomenon. To test wether HIV-1 reactivation is mediated by LTR transactivation, the HeLa HIV-1 CAT cell line, which carries an integrated DNA cartridge containing CAT gene under control of HIV-1 LTR, was also exposed to an oxidative stress. RESULTS: Hydrogen peroxide exposure of U1 cells leads to an increased reverse transcriptase (RT) activity in supernatant fluid. Over the optimal concentrations range (0.5 to 1 mM), a four to fivefold stimulation level is reached. Below these concentrations, stress conditions are not sufficient and above, they induce a too important lethal effect. Immunofluorescence carried out on stressed U1 cells shows that H2O2 leads to HIV-1 gene expression activation and not to a release of viral particles from damaged cells. H2O2 also induces a stimulation of CAT activity in HeLa HIV-1 CAT cells. Intracellular singulet oxygen (1O2) is also able to induce an increase of RT activity in supernatant fluid of U1 and ACH-2 cells and a stimulation of CAT activity in HeLa HIV-1 CAT cells. A dose-response curve can also be demonstrated. In order to transpose these in vitro experiments to situations encountered in vivo, activated phagocytes were cocultivated with HeLa HIV-1 CAT cells. A weak stimulation of CAT activity was detected. CONCLUSIONS: Cellular oxidative damages induce HIV-1 LTR transactivation leading to viral gene expression and consequently to a burst of virus production. DNA damages induced by oxidative stress could be at the onset of HIV-1 reactivation. Experiments are now in progress to elucidate the mechanisms leading to HIV-1 reactivation after an oxidative stress. [less ▲]

Detailed reference viewed: 18 (2 ULg)
See detailHIV-1 reactivation after an oxidative stress
Legrand, Sylvie ULg; Hoebeke, Maryse ULg; Vaira, Dolorès ULg et al

in Archives Internationales de Physiologie, de Biochimie et de Biophysique (1992), 100

Detailed reference viewed: 12 (5 ULg)
See detailVaricella-zoster virus: an ultrastructural study of the assembly phases
Schoonbroodt, Sonia; Piette, Jacques ULg; Rentier, Bernard ULg

in Archives Internationales de Physiologie, de Biochimie et de Biophysique (1992), 100

Detailed reference viewed: 6 (2 ULg)
See detailTwo-dimensional study of varicella-zoster virus proteins
Debrus, S.; Lebon, L.; Schoonbroodt, Sonia et al

in Archives Internationales de Physiologie, de Biochimie et de Biophysique (1992), 100(2), 39

Detailed reference viewed: 15 (6 ULg)
See detailMolecular characterization of varicella-zoster virus gene expression
Defechereux, Patricia; Baudoux, Laurence; Jackers, Pascale ULg et al

in Archives Internationales de Physiologie, de Biochimie et de Biophysique (1992), 100

Detailed reference viewed: 9 (2 ULg)
Peer Reviewed
See detailPhotosensitized Production of Singlet Oxygen by Merocyanine 540 Bound to Liposomes
Hoebeke, Maryse ULg; Piette, Jacques ULg; van de Vorst, A.

in Journal of Photochemistry and Photobiology B : Biology (1991), 9(3-4), 281-94

The production of singlet oxygen by merocyanine 540 was studied in dimyristoyl-phosphatidylcholine liposomes using two singlet oxygen probes: 9,10-anthracenedipropionic acid (water soluble) and 9,10 ... [more ▼]

The production of singlet oxygen by merocyanine 540 was studied in dimyristoyl-phosphatidylcholine liposomes using two singlet oxygen probes: 9,10-anthracenedipropionic acid (water soluble) and 9,10-dimethylanthracene (liposoluble). Upper and lower limits of singlet oxygen quantum yield for bound merocyanine 540 were determined to be 0.055 and 0.015 respectively. The diffusion characteristics of singlet oxygen were examined using the isotropic enhancement effect of D2O and the inhibitory effect of sodium azide. It was shown that 1O2 spent more than 87% of its lifetime in a vesicle environment. When the singlet-reacting substrate and the dye were both located in the bilayer, approximately 40% of the singlet oxygen remained in the liposomes where it was originally generated. [less ▲]

Detailed reference viewed: 17 (0 ULg)
Peer Reviewed
See detailAn in vivo model of varicella-zoster virus latent infection of dorsal root ganglia
Sadzot-Delvaux, Catherine ULg; Merville, Marie-Paule ULg; Delrée, P. et al

in Journal of Neuroscience Research (1990), 26(1), 83-89

We describe here the first in vivo model of varicella-zoster virus (VZV) latent infection in the adult rat peripheral nervous system. Infected Mewo cells were injected subcutaneously along the spine of ... [more ▼]

We describe here the first in vivo model of varicella-zoster virus (VZV) latent infection in the adult rat peripheral nervous system. Infected Mewo cells were injected subcutaneously along the spine of healthy adult rats. No clinical sign of infection was observed even 9 months after inoculation. Humoral immune response to VZV was detected in all infected animals throughout the study (9 months). The presence of viral material in dissociated and cultured dorsal root ganglia (DRG) from inoculated animals was studied by immunoperoxidase and in situ hybridization. When DRGs from infected animals were plated in culture from 1 month and up to 9 months after inoculation, viral nucleic acids and proteins were detected in neurons. Furthermore, trypsinization and subcultivation of infected neurons in culture is needed to reactivate infectious virus at least in some of the neurons. This model provides a useful tool for studying 1) the molecular mechanisms leading to an in vivo latency, 2) the role of the immune system, in particular cellular immunity, on the establishment, maintenance, and reactivation of latency, 3) the neurotropism of mutant viruses, and 4) the effects of antiviral agents. [less ▲]

Detailed reference viewed: 21 (1 ULg)
Peer Reviewed
See detailAcute and persistent varicella-zoster virus infection of human and murine neuroblastoma cell lines
Bourdon-Wouters, C.; Merville, Marie-Paule ULg; Sadzot-Delvaux, Catherine ULg et al

in Journal of Neuroscience Research (1990), 26(1), 90-97

Human and murine neuroblastoma cell lines were infected in vitro with varicella-zoster virus (VZV). Infected human neuroblastoma cells (IMR-32) supported the synthesis of abundant viral antigens as ... [more ▼]

Human and murine neuroblastoma cell lines were infected in vitro with varicella-zoster virus (VZV). Infected human neuroblastoma cells (IMR-32) supported the synthesis of abundant viral antigens as detected by indirect immunoperoxidase labeling using human serum rich in anti-VZV antibodies and did not survive the infection. In situ hybridization (ISH) with VZV-cloned probes revealed a strong hybridization signal in these infected cells. During cultivation, the virus was released in the culture medium, and viral polypeptides were revealed by Western blotting of infected cells, using either a monoclonal anti-gpI antibody or a rabbit antiserum. All these findings indicate that IMR-32 cells support a productive and lytic infection by VZV, whether infected by cell-free virus or by cocultivation with infected cells. Murine neuroblastoma cells (neuro-2A) survived VZV infection and did not produce any infectious virus. No VZV-specific proteins were detected in infected cells either by immunolabeling or by Western blotting. However, viral nucleic acids could be detected by ISH, indicating that mouse neuroblastoma cells displayed a nonproductive, nonlytic infection. Infected neuro-2A cells have been examined by ISH using probes corresponding to immediate early (IE) genes 4, 62, and 63 and late (L) gene 31 encoding gpII. A strong hybridization signal was detected when infected cells were probed with a fragment containing the IE genes 62 and 63. Lower levels of hybridization were detected with the other probes, corresponding to IE or L genes. These systems allow comparative molecular analysis of persistent and acute infection of nerve cells by VZV. [less ▲]

Detailed reference viewed: 27 (0 ULg)
Full Text
Peer Reviewed
See detailTyping of human papillomaviruses in genital specimens by DNA hybridization
Lauricella, M.-A.; Piette, Jacques ULg; Lifrange, Eric ULg et al

in Archives Internationales de Physiologie et de Biochimie (1990), 98(2), 34

Detailed reference viewed: 9 (0 ULg)
Peer Reviewed
See detailActivation of human immunodeficiency virus type 1 by an oxidative stress
Legrand-Poels, Sylvie ULg; VAIRA, Dolorès ULg; PINCEMAIL, Joël ULg et al

in AIDS Research and Human Retroviruses (1990)

Detailed reference viewed: 4 (0 ULg)
Peer Reviewed
See detailReactivation of HIV-1 after an oxidative stress
Piette, Jacques ULg; Legrand-Poels, Sylvie; Vaira, Dolorès ULg et al

in Free Radicals in Biology and Medicine (1990), 9(Suppl. A), 5

Detailed reference viewed: 5 (0 ULg)
See detailDe la photophysique des molécules aromatiques en solution aux mécanismes de leurs effets biologiques
Piette, Jacques ULg; Hoebeke, Maryse ULg; Seret, Alain ULg

in Physicalia Magazine (1990), 12

Les études des interactions entre la lumière et la matière relèvent du domaine de la physique mais elles ont des implications importantes en chimie et en biologie. Dans cet article, nous présenterons ... [more ▼]

Les études des interactions entre la lumière et la matière relèvent du domaine de la physique mais elles ont des implications importantes en chimie et en biologie. Dans cet article, nous présenterons trois exemples, dans lesquels le phénomène de l'absorption lumineuse par certains chromophores et les réactions photochimiques, initiées à partir des différents états excités, constituent les étapes primaires de réactions photobiologiques qui peuvent avoir des conséquences aussi diverses que l'apparition de mutations dans les chromosomes et l'oxydation des constituants de membranes. Ces réactions biologiques sont appelées réactions de photosensibilisation et elles ont des implications importantes dans de nombreux domaines des sciences fondamentales et appliquées. [less ▲]

Detailed reference viewed: 25 (3 ULg)
Peer Reviewed
See detailRose Bengal triplet state behaviour in sodium dodecyl sulfate micelles
Seret, Alain ULg; Piette, Jacques ULg; Van de Vorst, Albert

Poster (1989, August)

Detailed reference viewed: 37 (1 ULg)
Peer Reviewed
See detailIntérêt du typage viral des papillomavirus humains (HPV) en relation avec les neoplasies des muqueuses genitales
Lifrange, Eric ULg; Lauricella, M.; Rentier, Bernard ULg et al

in Revue Médicale de Liège (1989), 44(1), 1-14

Detailed reference viewed: 40 (2 ULg)
Full Text
Peer Reviewed
See detailVaricella-zoster virus infection of adult rat sensory neurons in vitro.
Merville-Louis, M. P.; Sadzot-Delvaux, Catherine ULg; Delree, P. et al

in Journal of Virology (1989), 63(7), 3155-60

We report here an in vitro model of neuronal infection by varicella-zoster virus (VZV). Such a model has been achieved by using dissociated adult rat dorsal root ganglia cells infected by cocultivation ... [more ▼]

We report here an in vitro model of neuronal infection by varicella-zoster virus (VZV). Such a model has been achieved by using dissociated adult rat dorsal root ganglia cells infected by cocultivation with VZV-infected MRC5 cells or with cell-free virus. Indirect VZV immunolabeling, in situ hybridization, and neuron-specific immunolabeling demonstrated that VZV infection occurred selectively in neurons. VZV-specific immunolabeling detected a few neurons 1 or 2 days postinfection but not later. Genome detection using cloned VZV DNA probes revealed a hybridization signal primarily with RNA. Within 1 to 6 days postinfection, a progressive increase of VZV-specific hybridization was observed in up to 50% of the neurons. RNAs corresponding to immediate-early, early, and late genes were found, and transcripts of immediate-early gene 63 were particularly abundant. [less ▲]

Detailed reference viewed: 16 (2 ULg)
See detailImmunomodulation of varicella-zoster virus antigens
Marc, Ph.; Sadzot-Delvaux, Catherine ULg; Merville-Louis, M. P. et al

Poster (1989)

Detailed reference viewed: 11 (2 ULg)
See detailIn vivo model of varicella-zoster virus latency in the nervous system
Sadzot-Delvaux, Catherine ULg; Merville-Louis, Marie Paule; Delrée, P. et al

Conference (1989)

Detailed reference viewed: 8 (1 ULg)
Peer Reviewed
See detailLatent infection in vivo by the varicella-zoster virus (VZV) in the rat nervous system
Sadzot-Delvaux, Catherine ULg; Merville, Marie-Paule ULg; Delrée, P. et al

in Archives Internationales de Physiologie et de Biochimie (1989), 97

Detailed reference viewed: 10 (1 ULg)