References of "Piette, Jacques"
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See detailLessons to be learned from varicella-zoster virus
Rentier, Bernard ULg; Piette, Jacques ULg; Baudoux, Laurence et al

in Veterinary Microbiology (1996), 53(1-2), 55-66

Varicella-zoster virus (VZV) is an alphaherpesvirus responsible for two human diseases: chicken pox and shingles. The virus has a respiratory port of entry. After two successive viremias, it reaches the ... [more ▼]

Varicella-zoster virus (VZV) is an alphaherpesvirus responsible for two human diseases: chicken pox and shingles. The virus has a respiratory port of entry. After two successive viremias, it reaches the skin where it causes typical lesions. There, it penetrates the peripheral nervous system and it remains latent in dorsal root ganglia. It is still debatable whether VZV persists in neurons or in satellite cells. During latency, VZV expresses a limited set of transcripts of its immediate early (IE) and early (E) genes but no protein has been detected. Mechanisms of reactivation from ganglia have not been identified. However, dysfunction of the cellular immune system appears to be involved in this process. The cell-associated nature of VZV has made it difficult to identify a temporal order of gene expression, but there appears to be a cascade mechanism as for HSV-1. The lack of high titre cell-free virions or recombination mutants has hindered so far the understanding of VZV gene functions. Five genes, ORFs 4, 10, 61, 62, and 63 that encode regulatory proteins could be involved in VZV latency. ORF4p activates gene promoters with basal activities. ORF10p seems to activate the ORF 62 promoter. ORF61p has trans-activating and trans-repressing activities. The major IE protein ORF62p, a virion component, has DNA-binding and regulatory functions, transactivates many VZV promoters and even regulates its own expression. ORF63p is a nuclear IE protein of yet unclear regulatory functions, abundantly expressed very early in infection. We have established an animal model of VZV latency in the rat nervous system, enabling us to study the expression of viral mRNA and protein expression during latency, and yielding results similar to those found in humans. This model is beginning to shed light on the molecular events in VZV persistent infection and on the regulatory mechanisms that maintain the virus in a latent stage in nerve cells. [less ▲]

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See detailVimentin Expression in Cervical Carcinomas: Association with Invasive and Migratory Potential
Gilles, Christine ULg; Polette, M.; Piette, Jacques ULg et al

in Journal of Pathology (The) (1996), 180(2), 175-80

Vimentin is an intermediate filament protein normally expressed in mesenchymal cells, but evidence is accumulating in the literature which suggests that the aberrant expression of vimentin in epithelial ... [more ▼]

Vimentin is an intermediate filament protein normally expressed in mesenchymal cells, but evidence is accumulating in the literature which suggests that the aberrant expression of vimentin in epithelial cancer cells might be related to local invasiveness and metastatic potential. Vimentin expression has previously been associated with invasive properties in an in vitro model consisting of a set of HPV-33-transformed cervical keratinocyte cell lines. In the present study, in order to emphasize those in vitro findings, the expression of vimentin has been investigated in cervical neoplasms of different grades, using immunohistochemistry. A clear association is reported between vimentin expression and metastatic progression, since vimentin was detected in all invasive carcinomas and lymph node metastases, but not in CIN III lesions. These in vivo results are compared with present and previous data obtained in vitro on cervical keratinocyte cell lines, where vimentin expression also correlated with in vitro invasiveness. [less ▲]

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See detailViral Integration Sites in Human Papilloma Virus-33-Immortalized Cervical Keratinocyte Cell Lines
Gilles, Christine ULg; Piette, Jacques ULg; Ploton, D. et al

in Cancer Genetics & Cytogenetics (1996), 90(1), 63-9

The viral organization of HPV-33 was determined by Southern blotting in 2 HPV-33-immortalized cervical cell lines (CK11 and CK12) and compared to our previous results obtained on 10 other already ... [more ▼]

The viral organization of HPV-33 was determined by Southern blotting in 2 HPV-33-immortalized cervical cell lines (CK11 and CK12) and compared to our previous results obtained on 10 other already characterized HPV-33-immortalized cell lines (CK1 to CK10). As observed in CK1 to CK10, the viral DNA was found integrated in the cellular genome of CK11 and CK12. However, in CK11 and CK12, the integrated viral genome was deleted and mostly limited to the URR and the E6-E7 ORFs, stressing the importance of those sequences in the immortalization process. Furthermore, CK11 and CK12 showed a unique and identical integration site, as observed in CK1 to CK10, which also harbored HPV-33 integrated at a unique and identical site (which was however different from the one evidenced in CK11 and CK12). Indeed, in situ hybridizations on chromosomes allowed the precise localization of the viral DNA on chromosome 13q33-34 in CK1 to CK10 whereas it was mapped to chromosome 9p13 in CK11 and CK12. We discuss the possibility that integration of HPV-33 at those two particular sites has conferred some growth advantages to the cells and could have thus played a crucial role in the immortalization. [less ▲]

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See detailEnhancement of Varicella-Zoster virus infection in cell lines expressing ORF4- or ORF62-encoded proteins
Schoonbroodt, Sonia; Piette, Jacques ULg; Baudoux, Laurence et al

in Journal of Medical Virology (1996), 49(4), 264-273

Varicella-Zoster virus (VZV) open reading frames 4 (ORF4) and 62 (ORF62) encode putative immediate-early proteins (ORF4p and ORF62p, respectively) which are strong transactivators of other VZV genes and ... [more ▼]

Varicella-Zoster virus (VZV) open reading frames 4 (ORF4) and 62 (ORF62) encode putative immediate-early proteins (ORF4p and ORF62p, respectively) which are strong transactivators of other VZV genes and are involved in the very early stages of viral infection. ORF4p and ORF62p transactivate immediate-early and early gene promoters but have little or no effect on late gene promoters. To investigate the effect of ORF4p or ORF62p overexpression on the viral replication cycle, we constructed Vero cell lines expressing those genes under the control of the human cytomegalovirus major immediate-early promoter. VZV OKA infection of these stably transformed cell lines was followed-up using VZV glycoprotein E (gE) antigen quantification and virus titration. Upon serial passaging of infection in these cell lines expressing functionally active ORF4p or ORF62p, a 5- to 10-fold increase in viral gE antigen production was observed. Viral titers also demonstrated a 2- to 5-fold increase in viral production in these transformed cell lines. These results emphasize the role that both ORF4p and ORF62p play in enhancing the VZV replicative cycle. (C) 1996 Wiley-Liss, Inc. [less ▲]

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See detailIntracellular distribution of the ORF4 gene product of varicella-zoster virus is influenced by the IE62 protein
Defechereux, Patricia; Debrus, Serge; Baudoux, Laurence et al

in Journal of General Virology (1996), 77(Part 7), 1505-1513

Varicella-zoster virus (VZV) open reading frame 4-encoded protein (IE4) possesses transactivating properties for VZV genes as well as for genes of heterologous viruses, The major regulatory immediate ... [more ▼]

Varicella-zoster virus (VZV) open reading frame 4-encoded protein (IE4) possesses transactivating properties for VZV genes as well as for genes of heterologous viruses, The major regulatory immediate-early protein of VZV (IE62) is a transactivator of VZV gene expression, In transfection assays, IE4 has been shown to enhance activation induced by IE62, To investigate the functional interactions underlying this observation, indirect immunofluorescence studies were undertaken to determine whether IE62 could influence IE4 intracellular localization in transfected cells, In single transfections, IE4 was predominantly found in cytoplasm, In cotransfection with IE62, the IE4 localization pattern was altered, with nuclear staining predominating over cytoplasmic staining, This effect was specific to the IE62 protein since the gene products of ORF63 and ORF61, which are also regulatory proteins, did not influence IE4 distribution, The use of IE62 mutants indicated that IE62 influence is independent of its transactivation function and that the integrity of regions 3 and 4 is required, IE62 remained nuclear whether IE4 was present or not, These observations underline differences in the regulation of gene expression between VZV proteins and their herpes simplex virus type 1 homologues, In infected cells, IE4 was only sometimes found to colocalize with IE62 in nuclei, This observation suggests that when all VZV proteins are present, complex interactions probably occur which could diminish the influence of IE62. [less ▲]

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See detailDistribution of varicella-zoster virus and herpes simplex virus in disseminated fatal infections
Nikkels, Arjen ULg; Delvenne, Philippe ULg; Sadzot-Delvaux, Catherine ULg et al

in Journal of Clinical Pathology (1996), 49(3), 243-248

AIMS: To study the cutaneous and visceral distribution of herpes simplex virus (HSV) and varicella zoster virus (VZV) in fatal infections. METHODS: Standard histology, immunohistochemistry (monoclonal ... [more ▼]

AIMS: To study the cutaneous and visceral distribution of herpes simplex virus (HSV) and varicella zoster virus (VZV) in fatal infections. METHODS: Standard histology, immunohistochemistry (monoclonal antibodies VL8 and VL2 and polyclonal antibody IE63 directed against VZV; monoclonal antibodies IBD4 and HH2 and polyclonal antibodies directed against HSVI and HSVII) and in situ hybridisation (anti-HSV and anti-VZV probes) were applied to formalin fixed, paraffin wax sections. RESULTS: On histological examination, Herpesviridae infection was evident in various organs including the lungs, liver and skin. In addition, immunohistochemistry and in situ hybridisation revealed the presence of HSV and VZV antigens and nucleic acids in several cell types and tissues showing no cytopathological alterations suggestive of Herpesviridae infection. The organs with histological evidence of infection also contained VZV or HSV antigens and their genes. CONCLUSIONS: These findings suggest that organ failure in disseminated VZV and HSV infections is primarily caused by HSV or VZV induced cell damage and lysis. They also indicate that immunohistochemistry and in situ hybridisation can provide an accurate, type-specific diagnosis on formalin fixed, paraffin wax embedded tissue even when classic histological and cytological characteristics are lacking. [less ▲]

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See detailHigh Level of Mt-Mmp Expression Is Associated with Invasiveness of Cervical Cancer Cells
Gilles, Christine ULg; Polette, M.; Piette, Jacques ULg et al

in International Journal of Cancer = Journal International du Cancer (1996), 65(2), 209-13

MMP-2 (gelatinase A) has been associated with the invasive potential of many cancer cells both in vitro and in vivo. It is now becoming clear that the activation of this enzyme might be a key step in ... [more ▼]

MMP-2 (gelatinase A) has been associated with the invasive potential of many cancer cells both in vitro and in vivo. It is now becoming clear that the activation of this enzyme might be a key step in tumor invasion. This activation process has been shown to be a membrane-associated pathway inducible by various agents such as collagen type I, concanavalin A or TGF-beta, but its physiological regulation is still largely unresolved. MT-MMP was recently discovered and described as a potential gelatinase-A activator. In the present study, we investigated the expression of MT-MMP (membrane-type metalloproteinase) in cervical cancer cells both in vitro and in vivo. Comparing several in vitro-transformed cervical cell lines, previously shown to display different invasive potentials, our results showed that the ability of cells to overexpress MT-MMP mRNA following ConA induction correlated with their ability to activate gelatinase A and with a highly invasive behavior. Moreover, using immunohistochemistry and in situ hybridization, we found a higher level of MT-MMP expression in invasive cervical carcinoma and lymph node metastases compared to its expression in non-invasive CIN III lesions. Our in vivo observations also clearly demonstrated a cooperation between stromal and tumor cells for the production of MT-MMP. Taken together, our results clearly correlated high level MT-MMP expression with invasiveness, and thus suggested that MT-MMP might play a crucial role in cervical tumor invasion. [less ▲]

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See detailAnalysis of VZV IE62 protein DNA binding sites on VZV gene promoters
Baudoux, Laurence; Remacle, V.; Defechereux, Patricia et al

Conference (1996)

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See detailExpression of protein encoded by varicella-zoster virus open reading frame 63 in latently infected human ganglionic neurons
Mahalingam, Ravy; Wellish, Mary; Cohrs, Randall et al

in Proceedings of the National Academy of Sciences of the United States of America (1996), 93(5), 2122-2124

The ganglionic cell type in which varicellazoster virus (VZV) is latent in humans was analyzed by using antibodies raised against in vitro-expressed VZV open reading frame 63 protein, VZV open reading ... [more ▼]

The ganglionic cell type in which varicellazoster virus (VZV) is latent in humans was analyzed by using antibodies raised against in vitro-expressed VZV open reading frame 63 protein, VZV open reading frame 63 protein was detected exclusively in the cytoplasm of neurons of latently infected human trigeminal and thoracic ganglia. This is, to our knowledge, the first identification of a herpesvirus protein expressed during latency in the human nervous system. [less ▲]

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See detailDistribution of varicella-zoster virus gpI and gpII and corresponding genome sequences in the skin
Nikkels, Arjen ULg; Delvenne, Philippe ULg; Debrus, S. et al

in Journal of Medical Virology (1995), 46(2), 91-96

In the course of varicella-zoster virus (VZV) infection, some viral capsid antigens are found in the epidermis and dermis. The aim of this study was to investigate the localisation of two major VZV ... [more ▼]

In the course of varicella-zoster virus (VZV) infection, some viral capsid antigens are found in the epidermis and dermis. The aim of this study was to investigate the localisation of two major VZV glycoproteins (gpI and gpII) and of their respective genes in the skin. The distribution of VZV gpI and II in 27 formalin fixed paraffin embedded skin biopsies from herpes tester eruptions were compared by immunohistochemistry. Double immunostaining was carried our to identify infected cells. The presence of viral nucleic acids coding for gpI and gpII was examined by in situ hybridisation. The distribution of gpI and gpII and their corresponding genome sequences was similar in the epidermis, gpI and gpII were also detected in dermal FXIIIa positive dendrocytes, in Mac 387 and CD68 positive macrophages, and in perineural and endothelial cells. However, the corresponding viral nucleic acids were rarely and barely detected in these cells of the dermis. It is concluded that VZV infection of epithelial cells follows a different course than in dermal cells. (C) 1995 Wiley-Liss, Inc. [less ▲]

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See detailMutational analysis of varicella-zoster virus major immediate-early protein IE62
Baudoux, Laurence; Defechereux, Patricia; Schoonbroodt, Sonia et al

in Nucleic Acids Research (1995), 23(8), 1341-1349

The varicella-zoster virus (VZV) open reading frame 62 encodes an immediate-early protein (IE62) that transactivates expression of various VZV promoters and autoregulates its own expression in transient ... [more ▼]

The varicella-zoster virus (VZV) open reading frame 62 encodes an immediate-early protein (IE62) that transactivates expression of various VZV promoters and autoregulates its own expression in transient expression assays. In Vero cells, IE62 was shown to transactivate the expression of all putative immediate-early (IE) and early (E) genes of VZV with an up-regulating effect at low intracellular concentrations. To define the functional domains involved in the regulatory properties of IE62, a large number of in-frame insertions and deletions were introduced into a plasmid-borne copy of the gene encoding IE62. Studies of the regulatory activities of the resultant mutant polypeptides in transient expression assays allowed to delineate protein regions important for repression of its own promoter and for transactivation of a VZV putative immediate-early gene (ORF61) promoter and an early gene (ORF29) promoter. This mutational analysis resulted in the identification of a new functional domain situated at the border between regions 4 and 5 which plays a crucial role in the IE62 regulatory functions. This domain turned out to be very well conserved amongst homologous alphaherpesvirus regulatory proteins and appeared to be rich in bulky hydrophobic and proline residues, similar to the proline-rich region of the CAAT box binding protein CTF-1. By immunofluorescence, a nuclear localization signal has been mapped in region 3. [less ▲]

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See detailTranscription factor NF-kB is activated by photosensitization generating oxidative DNA damages
Legrand-Poels, Sylvie ULg; Bours, Vincent ULg; Piret, Bernard et al

in Journal of Biological Chemistry (1995), 270(12), 6925-6934

Reactive oxygen intermediates like hydrogen peroxide (H2O2) have been shown to serve as messengers in the induction of NF-kappa B and, then, in the activation and replication of human immunodeficiency ... [more ▼]

Reactive oxygen intermediates like hydrogen peroxide (H2O2) have been shown to serve as messengers in the induction of NF-kappa B and, then, in the activation and replication of human immunodeficiency virus (HIV)-1 in human cells. Because H2O2 can be converted into the highly reactive OH. at various locations inside the cells, we started to investigate the generation of Reactive oxygen intermediates by photosensitization. This technique is based on the use of a photosensitizer which is a molecule absorbing visible light and which can be located at various sites inside the cell depending on its physicochemical properties. In this work, we used proflavine (PF), a cationic molecule having a high affinity for DNA, capable of intercalating between DNA base pairs. Upon visible light irradiation, intercalated PF molecules oxidize guanine residues and generate DNA single-strand breaks. In lymphocytes or monocytes latently infected with HIV-1 (ACH-2 or U1, respectively), this photosensitizing treatment induced a cytotoxicity, an induction of NF-kappa B, and a reactivation of HIV-1 in cells surviving the treatment. NF-kappa B induction by PF-mediated photosensitization was not affected by the presence of N-acetyl-L-cysteine while strong inhibition was recorded when the induction was triggered by H2O2 or by phorbol 12-myristate 13-acetate. Another transcription factor like AP-1 is less activated by this photosensitizing treatment. In comparison with other inducing treatments, such as phorbol 12-myristate 13-acetate or tumor necrosis factor alpha, the activation of NF-kappa B is slow, being optimal 120 min after treatment. These kinetic data were obtained by following, on the same samples, both the appearance of NF-kappa B in the nucleus and the disappearance of I kappa B-alpha in cytoplasmic extracts. These data allow us to postulate that signaling events, initiated by DNA oxidative damages, are transmitted into the cytoplasm where the inactive NF-kappa B factor is resident and allow the translocation of p50/p65 subunits of NF-kappa B to the nucleus leading to HIV-1 gene expression. [less ▲]

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See detailIron chelation decreases NF-kappaB and HIV-1 activation due to oxidative stress
Sappey, Christine; Boelaert, J. R.; Legrand-Poels, Sylvie ULg et al

in AIDS Research and Human Retroviruses (1995)

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See detailNF-kappaB transcription factor activation by hydrogen peroxide can be decreased by 2,3-dihydroxybenzoic acid and its ethylester derivative
Sappey, Christine; Boelaert, J. R.; Legrand-Poels, Sylvie ULg et al

in Archives of Biochemistry & Biophysics (1995)

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See detailNF-kappaB transcription factor and human immunodeficiency virus type 1 (HIV-1) are activated by methylene blue photosensitization
Piret, Bernard; Legrand-Poels, Sylvie ULg; Sappey, Christine et al

in European Journal of Biochemistry (1995)

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See detailHIV-1 and NF-kappaB activation by photo-oxidative stress
Piette, Jacques ULg; Legrand-Poels, Sylvie ULg; Piret, Bernard

in Photochemistry & Photobiology (1995)

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