Puumala orthohantavirus causes hemorrhagic fever with renal syndrome (HFRS) characterized by acute kidney injury (AKI), an abrupt decrease in renal function. Creatinine is routinely used to detect and quantify AKI; however, early AKI may not be reflected in increased creatinine levels. Therefore, kidney injury markers that can predict AKI are needed. The potential of the kidney injury markers urea, cystatin C, α1-microglobulin (A1M) and neutrophil gelatinase-associated lipocalin (NGAL) to detect early AKI during HFRS was studied by quantifying the levels of these markers in consecutively obtained plasma (P) and urine samples (U) for 44 HFRS patients. P-cystatin C and U-A1M levels were significantly increased during early HFRS compared to follow-up. In a receiver operating characteristic (ROC) curve analysis, P-cystatin C, U-A1M and P-urea predicted severe AKI with area under the curve 0.72, 0.73 and 0.71, respectively, whereas the traditional kidney injury biomarkers creatinine and U-albumin did not predict AKI. Nearly half of the HFRS patients (41%) fulfilled the criteria for shrunken pore syndrome, which was associated with the level of inflammation as measured by P-CRP. P-cystatin C and U-A1M are more sensitive and earlier markers compared to creatinine in predicting kidney injury during HFRS.

The human cytomegalovirus (HCMV) terminase complex consists of several components acting together to cleave viral DNA into unit length genomes and translocate them into capsids, a critical process in the production of infectious virions subsequent to DNA replication. Previous studies suggest that the carboxyl-terminal portion of the pUL56 subunit interacts with the pUL89 subunit. However, the specific interacting residues of pUL56 remain unknown. We identified a conserved sequence in the C-terminal moiety of pUL56 (₆₇₁WMVVKYMGFF₆₈₀). Overrepresentation of conserved aromatic amino acids through 20 herpesviruses homologues of pUL56 suggests an involvement of this short peptide into the interaction between the larger pUL56 terminase subunit and the smaller pUL89 subunit. Use of Alpha technology highlighted an interaction between pUL56 and pUL89 driven through the peptide ₆₇₁WMVVKYMGFF₆₈₀. A deletion of these residues blocks viral replication. We hypothesize that it is the consequence of the disruption of the pUL56-pUL89 interaction. These results show that this motif is essential for HCMV replication and could be a target for development of new small antiviral drugs or peptidomimetics.

Background: Congenital CMV infection is the leading cause of neonatal neurological deficit. We herein studied in vitro and ex vivo the potential of the hyperimmune globulin Cytotect CP^® (Biotest, Germany) for congenital infection prevention and treatment. Methods: In vitro neutralization assays were conducted in fibroblasts and retinal epithelial cells on the CMV strains TB40/E and VHL/E to determine the 50% and 90% neutralizing doses (ND50 and ND90). The toxicity was assessed by measuring LDH release. Ex vivo assays were conducted in first-trimester villi explants with the TB40/E strain, namely, neutralization assays, the prevention of villi infection, and the inhibition of viral replication in infected villi. Viability was assessed by β-HCG quantification in supernatants. Results: The in vitro neutralization tests showed that Cytotect CP^®® inhibits the development of infection foci (DN50: 0.011–0.014 U/mL for VHL/E and 0.032–0.033 U/mL for TB40E) without any toxicity. In the ex vivo neutralization assays, the DN50 were 0.011 U/mL on day 7 and 0.093 U/mL on day 14. For the prevention of villi infection, the EC50 was 0.024 U/mL on day 7. Cytotect-CP^® did not inhibit viral growth in infected villi. No impact on villi viability was observed. Conclusions: These results sustained that Cytotect CP^® has the potential to prevent CMV congenital infection.

L’infection à cytomégalovirus humain (CMVH) est un problème majeur de santé publique. Les traitements couramment utilisés contre l’infection à CMVH sont efficaces mais le plus souvent toxiques et donc proscrits pour la femme enceinte. Pour disposer d’outils performants et fiables pour évaluer les nouvelles thérapeutiques en phase préclinique, et dans un contexte de l’infection congénitale à CMVH, nous avons développé les essais antiviraux sur souches endothéliotropes et dans différents types cellulaires. De plus, nous avons optimisé deux modèles :1) Le modèle ex vivo d’histoculture de villosités placentaires, permettant d'évaluer les traitements au sein d’un tissu complexe. 2) Le modèle de souris humanisées par greffe d’explants placentaires pour l’étude de l’efficacité in vivo en tenant compte de la stricte spécificité d’espèce du CMV.En utilisant les méthodes développées in vitro et ex vivo nous avons évalué trois approches thérapeutiques nouvelles : une molécule modèle à cible cellulaire dérivée de l'artesunate et un nouvel analogue du cidofovir à faible toxicité, afin d’évaluer leur potentiel thérapeutique, et une approche immunologique utilisant des hyper-immunoglobulines à forte capacité neutralisante afin de mieux comprendre leur mécanisme d’action au niveau du placenta. Ainsi, ce travail de thèse s’inscrit dans un contexte d’évaluation de nouveaux antiviraux pour améliorer la prise en charge de l’infection à CMVH.