A novel polyomavirus was identified in a fatally diseased Gouldian finch (Erythrura gouldiae). The new polyomavirus, strain VL 1209, was detected using a broad-spectrum nested PCR.

Introduction. The aim of the study was to introduce a new BKV PCR protocol in our centre and to verify its accuracy as well as to assess the prevalence, risk factors of BK virus replication, course of BKV infection and therapeutic approaches in simultaneous pancreas and kidney (SPK) recipients in order to design a screening protocol. Methods. The results analysed by both Affigene® and Transplantation Virology, Basel PCR protocols were compared. Thereafter 183 SPK patients were examined to assess the prevalence of BK viremia, viruria and BKVN and to identify the risk factors of BKV replication. The cases of retransplantation after a graft loss due to BKVN were retrospectively described. Results. 100 of results were analysed according to the Affigene ® and Transplantation Virology, Basel PCR protocols with the accordance of 95%, Rho = 0,946, 95% CI: 0.920 - 0.963, P<0,0001, Bland-Altman plot analyses: bias Basel PCR protocol/Affigene® BKV trender: -0,1 (mean) *±1.96 SD: -1,6 - 1,3] for both methods. Point-prevalence was assessed in 183 patients; Viruria found in 17,3 %, viremia in 3.8% of patients. High-level viruria >107 copies/mL detected in 3,7% of patiets, high-level virémia >104 in 1,6% of patients simultaneously with high-level viruria. BKVN was found in 0,5% of patients. Diabetes duration...

Merkel cell polyomavirus (MCPyV) is a recently discovered human virus, having it's genome often integrated in a genome of Merkel carcinoma cells. Although this type of carcinoma is not so usual, it is very aggressive and it's incidence has been rising in last few years. It is not surprising that this virus is nowadays in the centre of scientific interest, as well as other pathogens and mechanisms affecting human life. Because the virus was discovered not so long ago, its research has been at the whole beginning. This diploma thesisaims to contribute to the study of this virus from the molecular-virology point of view. A neutralizing monoclonal antibody, type IgG2a, targeted against the main capsid protein of MCPyV, VP1, and recognizing its conformational epitote was prepared. This antibody was then used for a pilot study of VP1 VLPs MCPyV movement in mammalian cells. Results showed that the studied virus, at least particularly, utilizes caveolin-1-carrying vesicles for its movement in cells (colocalisation of VP1 VLPs and caveolin-1 was observedColocalisation with EEA1 marker of early endosomes, LamP2 marker of endolysosomal compartments or with BiP marker of endoplasmic reticulum was sporadic but significant. These preliminary results suggest that MCPyV might utilise an endocytic pathway leading...

Le polyomavirus à cellules de Merkel est aujourd’hui reconnu comme l’agent étiologique du carcinome à cellules de Merkel (CCM). Le cycle viral et les mécanismes de l’oncogenèse viro-induite sont peu connus et les connaissances se basent essentiellement sur les études menées notamment sur le polyomavirus SV40. L’objectif des travaux de thèse était d’identifier les interactions entre les protéines virales et les protéines cellulaires lors de l’infection ou dans le contexte du carcinome à cellules de Merkel (CCM). Pour identifier ces interactions, nous avons réalisé des cribles double hybride en levures sur les oncogènes du MCPyV et du BKPyV. Afin valider les interactions obtenues en levures, nous avons utilisé une méthode orthogonale de validation par complémentation en cellules de mammifères reposant sur la restauration de la luciférase de Gaussia princeps. La combinaison de ses deux techniques nous a permis de valider des interactions avec des partenaires cellulaires impliqués dans la régulation du cycle cellulaire ou encore de la voie Akt-mTOR. Les précédents travaux du laboratoire, qui portaient sur l’interactome des protéines mineures de capsides VP2/VP3, avaient également permis d’identifier des interactions avec des protéines de la voie NF-kB. Nous avons alors testé les interactions entre les oncogènes et la protéine mineure de capside VP2 avec des protéines cellulaires impliquées dans cette voie. Ces travaux nous ont conduits à tester l’activation de la voie, l’expression des gènes sous le contrôle de NF-kB et la régulation de l’apoptose. Les résultats obtenus montrent une action de la protéine VP2 sur l’activation de la voie NF-kB et une induction de l’apoptose. / The Merkel cell polyomavirus is now recognized as the etiologic agent of Merkel cell carcinoma (MCC). The viral cycle and viro-induced oncogenesis mechanisms are not fully understood and the knowledge is mainly based on the studies carried out particularly on the SV40 polyomavirus. The aim of our work is to identify interactions between viral proteins and cellular proteins during productive infection or in MCC context. To identify these interactions, we performed yeast two hybrid screens on MCPyV and BKPyV oncogenes, as control. To validate the interactions obtained in yeasts, we used an orthogonal method of validation by complementation in mammalian cells based on the restoration of Gaussia princeps luciferase. The combination of these two orthogonal techniques allowed us to validate interactions with cellular partners involved in cell cycle regulation or Akt-mTOR pathway. Previous lab work on VP2/VP3 minor capsid proteins allowed the identification of interactions with NF-kB pathway involved proteins. We examined the interactions between oncogenes, VP2, with the cellular proteins involved in this pathway. This work led us to evaluate pathway activation, genes expression under the control of NF-kB and apoptosis regulation. These results evidenced an action of the VP2 protein on the activation of NF-kB pathway and an induction of apoptosis.

Pacientes submetidos ao transplante de medula óssea, apresentando hematúria/cistite hemorrágica, tiveram amostras de urina analisadas pela microscopia eletrônica. Esta foi a técnica escolhida de pesquisa viral pela sua confiabilidade. Noventa em 402 pacientes submetidos ao transplante de medula óssea neste serviço apresentaram hematúria/cistite hemorrágica (incidência de 22%). O estudo por microscopia eletrônica foi realizado em 72 destes pacientes com hematúria/cistite hemorrágica (grupo de estudo), identificando 55,6% (40/72) de positividade viral. Foram também estudadas amostras de urina de 12 pacientes submetidos ao transplante de medula óssea sem hematúria/cistite hemorrágica (grupo controle); houve associação significante entre a presença de vírus e hematúria/cistite hemorrágica (p<0,01 - Teste exato de Fisher). No grupo com hematúria/cistite hemorrágica, 65% (26/40) dos vírus detectados pertenciam à família Poliomaviridae, 30% (12/40) à Adenoviridae, e 5% (2/40) foram positivos para ambas as famílias. Houve associação entre a positividade para vírus e a presença da doença enxerto-contra-hospedeiro (p=0,05-x2) e o de início tardio (>dia+21) da H/CH (P=0,04-x2), bem como entre a doença enxerto-contra-hospedeiro e a severidade da H/CH (p=0,04-x2). O presente estudo mostra que a microscopia eletrônica é uma ferramenta útil para detecção de vírus na urina de pacientes submetidos ao transplante de medula óssea apresentando hematúria/cistite hemorrágica e que o vírus provavelmente tem um papel no desenvolvimento do sangramento urinário, o qual é agravado pelo doença enxerto-contra-hospedeiro. A microscopia eletrônica deveria ser realizada rotineiramente para guiar as outras técnicas de detecção viral, como a imunocitoquímica e biologia molecular. / Patients submitted to bone marrow transplantation presenting hematuria/hemorrhagic cystitis had the urine analyzed by electron microscopy. It was the elected technique for viral search because its reliability. Ninety from 402 patients submitted to bone marrow transplantation at this service showed hematuria/hemorrhagic cystitis (incidence of 22%). Electron microscopy study was performed in 72 of these patients with hematuria/hemorrhagic cystitis (study group), identifying 55.5% (40/72) of viral positivity. It was also study the urine of 12 patients submitted to bone marrow transplantation without hematuria/hemorrhagic cystitis (control group); there was a significant association between the presence of virus and hematuria/hemorrhagic cystitis (p<0.01). In the hematuria/hemorrhagic cystitis group, 65% (26/40) of the virus belonged to Poliomaviridae family, 30% (12/40) to Adenoviridae, and 5% (2/40) to both families. There was association between the status of graft-versus-host disease and positivity for virus (p=0.05), as well as between graft-versus-host disease and the severity of hematuria/hemorrhagic cystitis (p=0.04). The present study shows that electron microscopy is a useful tool for detection of virus in urine of patients submitted to bone marrow transplantation presenting hematuria/hemorrhagic cystitis and that the virus probably play a role in the development of the urinary bleeding, which is aggravated by graft-versus-host disease. Electron microscopy should be performed routinely to guide the other techniques for viral detection, like immunocitochemistry and molecular biology.

Pacientes submetidos ao transplante de medula óssea, apresentando hematúria/cistite hemorrágica, tiveram amostras de urina analisadas pela microscopia eletrônica. Esta foi a técnica escolhida de pesquisa viral pela sua confiabilidade. Noventa em 402 pacientes submetidos ao transplante de medula óssea neste serviço apresentaram hematúria/cistite hemorrágica (incidência de 22%). O estudo por microscopia eletrônica foi realizado em 72 destes pacientes com hematúria/cistite hemorrágica (grupo de estudo), identificando 55,6% (40/72) de positividade viral. Foram também estudadas amostras de urina de 12 pacientes submetidos ao transplante de medula óssea sem hematúria/cistite hemorrágica (grupo controle); houve associação significante entre a presença de vírus e hematúria/cistite hemorrágica (p<0,01 - Teste exato de Fisher). No grupo com hematúria/cistite hemorrágica, 65% (26/40) dos vírus detectados pertenciam à família Poliomaviridae, 30% (12/40) à Adenoviridae, e 5% (2/40) foram positivos para ambas as famílias. Houve associação entre a positividade para vírus e a presença da doença enxerto-contra-hospedeiro (p=0,05-x2) e o de início tardio (>dia+21) da H/CH (P=0,04-x2), bem como entre a doença enxerto-contra-hospedeiro e a severidade da H/CH (p=0,04-x2). O presente estudo mostra que a microscopia eletrônica é uma ferramenta útil para detecção de vírus na urina de pacientes submetidos ao transplante de medula óssea apresentando hematúria/cistite hemorrágica e que o vírus provavelmente tem um papel no desenvolvimento do sangramento urinário, o qual é agravado pelo doença enxerto-contra-hospedeiro. A microscopia eletrônica deveria ser realizada rotineiramente para guiar as outras técnicas de detecção viral, como a imunocitoquímica e biologia molecular. / Patients submitted to bone marrow transplantation presenting hematuria/hemorrhagic cystitis had the urine analyzed by electron microscopy. It was the elected technique for viral search because its reliability. Ninety from 402 patients submitted to bone marrow transplantation at this service showed hematuria/hemorrhagic cystitis (incidence of 22%). Electron microscopy study was performed in 72 of these patients with hematuria/hemorrhagic cystitis (study group), identifying 55.5% (40/72) of viral positivity. It was also study the urine of 12 patients submitted to bone marrow transplantation without hematuria/hemorrhagic cystitis (control group); there was a significant association between the presence of virus and hematuria/hemorrhagic cystitis (p<0.01). In the hematuria/hemorrhagic cystitis group, 65% (26/40) of the virus belonged to Poliomaviridae family, 30% (12/40) to Adenoviridae, and 5% (2/40) to both families. There was association between the status of graft-versus-host disease and positivity for virus (p=0.05), as well as between graft-versus-host disease and the severity of hematuria/hemorrhagic cystitis (p=0.04). The present study shows that electron microscopy is a useful tool for detection of virus in urine of patients submitted to bone marrow transplantation presenting hematuria/hemorrhagic cystitis and that the virus probably play a role in the development of the urinary bleeding, which is aggravated by graft-versus-host disease. Electron microscopy should be performed routinely to guide the other techniques for viral detection, like immunocitochemistry and molecular biology.

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