No description available.

Proefschrift Universiteit van Amsterdam. / Met lit. opg. - Met samenvatting in het Nederlands.

Proefschrift Universiteit Maastricht. / Met bibliogr., lit. opg. - Met samenvatting in het Nederlands.

Proefschrift Universiteit Maastricht. / Met bibliogr., lit. opg. - Met samenvatting in het Nederlands.

No description available.

Les cellules NK, membres de l’immunité innée, sont impliquées dans le contrôle des infections virales et notamment l’infection à cytomégalovirus (CMV). Généralement bien tolérée chez l’individu immunocompétent, l’infection à CMV demeure associée à une forte morbidité chez les individus dont le système immunitaire est compromis (patients transplantés, coinfectés par le VIH) ou immature (fœtus et nouveaux nés). Lors de l’infection par le CMV, une relation étroite s’établit entre le système immunitaire et le virus. Celle-ci génère en effet une forte mobilisation, associée à un profond remodelage, de différents compartiments immuns. Au cours de ce travail de thèse, nous nous sommes intéressées à l’équilibre qui s’instaure entre le virus et le système immunitaire. Dans une première approche menée in vitro, nous avons exploré le rôle de différentes sous-populations NK dont les cellules NK NKG2C+, caractéristiques de l’infection à CMV, en réponse à des cellules endothéliales, isolées à partir de donneurs de rein, infectées par le CMV. Ensuite, une cohorte rare d’adultes immunocompétents souffrant d’une primo-infection symptomatique à CMV nous a permis d’étudier la course naturelle de l’infection à CMV. Cette approche ex vivo a constitué d’une part en l’analyse du polymorphisme de la réponse de l’hôte au virus, par l’étude phénotypique et transcriptomique non seulement de la réponse NK mais aussi d’autres effecteurs lymphocytaires. D’autre part, nous avons exploré l’impact du polymorphisme génétique viral, par le séquençage par NGS d’isolats cliniques du CMV, sur le pouvoir pathogène du virus. L’ensemble de ces travaux devrait contribuer à la meilleure compréhension du rôle des cellules NK dans le contrôle de l’infection à CMV. / NK cells are innate lymphocyte effectors involved in the control of viral infections and particularly cytomegalovirus (CMV) infection. Usually well tolerated in immunocompetent individuals, CMV infection remains life life-threatening in immunosuppressed patients, as transplant recipients or HIV-infected patients, or for fetuses in case of congenital infection. Upon primary infection, CMV establishes a close relationship with the immune system. CMV infection is known to drive an important immune response and to deeply imprint several immune compartments. In this present work, we focused on the host-virus balance that takes place upon infection. Through a first in vitro approach, we investigated the role of different NK cell subpopulations, including NKG2C+ NK cells which represent one of the hallmarks of CMV infection, in response to CMVinfected endothelial cells isolated from kidney donors. Then, an ex vivo approach was conducted in a cohort of immunocompetent adults diagnosed with symptomatic primary CMV infection. On one hand, our aim was to explore the host immune response polymorphism, through phenotypic and transcriptomic analyses of lymphocyte responses. On the other hand, we investigated the viral genome polymorphism, through NGS sequencing of clinical CMV isolates, which could modulate the viral pathogenicity. Taken together, these findings should contribute to the better understanding of the role of NK cells during the course of CMV infection.

Human cytomegalovirus (HCMV) is a ubiquitous virus that causes significant morbidity and mortality in immunocompromised individuals. Although there are prophylactic treatments available, all current antiviral drugs ultimately target the DNA polymerase, resulting in the increasing emergence of antiviral resistant strains in the clinical setting. There is a fundamental need for understanding the role of other essential genes in DNA replication as a foundation for developing new antiviral treatments that are safe and which utilize a mechanism of action different to existing therapies. In this study we looked at six HCMV replication genes encoding for the DNA polymerase accessory protein (UL44), single stranded DNA binding protein (UL57), primase (UL70), helicase (UL105), primase-helicase associated protein (UL102), and the putative initiator protein (UL84) in order to increase our understanding of their role in DNA replication. The aim of this project was to identify variation within these genes as well as to predict putative domains and motifs in order to ultimately express and study the functional properties of the HCMV primase (UL70) through the use of recombinant mutants. Sequencing of these genes revealed a high degree of conservation between the isolates with amino acid sequence identity of >97% for all genes. Using ScanProsite software from the Expert Protein Analysis System (ExPASy) proteomics server, we have mapped putative motifs throughout these HCMV replication genes. In particular, highly conserved putative Nlinked glycosylation sites were identified in UL105 that were also conserved across 33 homologues as well as several unique motifs including casein kinase II phosphorylation sites (CKII) in UL105 and UL84, a microbodies signal motif in UL57 and an integrin binding site in the UL102 helicase-primase associated protein. Our investigations have also elucidated motif-rich regions of the UL44 DNA polymerase accessory protein, mapped functionally important domains of the UL105 helicase and identified cysteine motifs that have implications for folding of the UL70 primase. Taken together, these findings provide insights to regions of these HCMV replication proteins that are important for post-translation modification, activation and overall function, and this information can be utilized to target further research into these proteins and advance the development of novel antiviral agents that target these processes.

No description available.

Human cytomegalovirus (HCMV) is a ubiquitous virus that causes significant morbidity and mortality in immunocompromised individuals. Although there are prophylactic treatments available, all current antiviral drugs ultimately target the DNA polymerase, resulting in the increasing emergence of antiviral resistant strains in the clinical setting. There is a fundamental need for understanding the role of other essential genes in DNA replication as a foundation for developing new antiviral treatments that are safe and which utilize a mechanism of action different to existing therapies. In this study we looked at six HCMV replication genes encoding for the DNA polymerase accessory protein (UL44), single stranded DNA binding protein (UL57), primase (UL70), helicase (UL105), primase-helicase associated protein (UL102), and the putative initiator protein (UL84) in order to increase our understanding of their role in DNA replication. The aim of this project was to identify variation within these genes as well as to predict putative domains and motifs in order to ultimately express and study the functional properties of the HCMV primase (UL70) through the use of recombinant mutants. Sequencing of these genes revealed a high degree of conservation between the isolates with amino acid sequence identity of >97% for all genes. Using ScanProsite software from the Expert Protein Analysis System (ExPASy) proteomics server, we have mapped putative motifs throughout these HCMV replication genes. In particular, highly conserved putative Nlinked glycosylation sites were identified in UL105 that were also conserved across 33 homologues as well as several unique motifs including casein kinase II phosphorylation sites (CKII) in UL105 and UL84, a microbodies signal motif in UL57 and an integrin binding site in the UL102 helicase-primase associated protein. Our investigations have also elucidated motif-rich regions of the UL44 DNA polymerase accessory protein, mapped functionally important domains of the UL105 helicase and identified cysteine motifs that have implications for folding of the UL70 primase. Taken together, these findings provide insights to regions of these HCMV replication proteins that are important for post-translation modification, activation and overall function, and this information can be utilized to target further research into these proteins and advance the development of novel antiviral agents that target these processes.

Proefschrift Universiteit van Amsterdam. / Met bibliogr., lit. opg. - Met een samenvatting in het Nederlands.