Interaction des virus avec la voie cellulaire de réponse à l’hypoxie

Des travaux récents réalisés in vitro montrent que l’appauvrissement du milieu de culture en oxygène (hypoxie) active la réplication du parvovirus humain B19, des virus du sarcome de Kaposi et de l’immunodéficience humaine, ainsi que l’expression de protéines virales oncogènes. Les mécanismes de cette régulation impliquent le plus souvent le facteur cellulaire majeur de réponse à l’hypoxie, HIF-1 (hypoxia inducible factor-1). Le dérèglement de ce facteur de transcription participe également au pouvoir oncogène de certains de ces virus.Recent studies show that low oxygen tension levels in cell culture up-regulate the replication of human B19 parvovirus, Kaposi’s sarcoma, and human immunodeficiency viruses as well as the expression of viral oncogenic proteins. The mechanisms of this regulation proceed with the major hypoxia-related factor, HIF-1 (hypoxia inducible factor-1). HIF-1 misregulation is implicated in the oncogenesis potential of some of these viruses

Comparative evaluation of the QIAsymphony RGQ system with the easyMAG/R-gene combination for the quantitation of cytomegalovirus DNA load in whole blood

Abstract Background The detection of cytomegalovirus (CMV) DNA in blood is a key feature of the virological surveillance of immunocompromised patients. Methods The QIAsymphony RGQ system (QIAGEN S.A.S., France) combines the extraction/distribution steps on QIAsymphony SP/AS instruments with amplification on a Rotor-Gene Q RT-PCR machine. This system was compared to a strategy combining an extraction step on the NUCLISENS easyMAG platform (bioMérieux) with the CMV R-gene kit (Argene) on 100 whole blood specimens collected from immunocompromised patients of the University Hospital of Saint-Etienne, France. Results The overall agreement between the two strategies was 86% (kappa coefficient of 0.67); the 14 discrepant results corresponded to low DNA loads. The 62 samples found positive with both tests were correlated (Pearson r coefficient of 0.70, P 10 copies/ml with the easyMAG/Argene strategy (P 10 copies/ml. The inter-run and intra-run variability was consistently lower with the QIAGEN platform. Conclusions These results validate the performance of the QIAsymphony RGQ system for the routine quantitation of CMV DNA. This fully-automated platform reduces the hands-on time and improves standardization, traceability and quality control assessment.</p

Hypoxia enhances human B19 erythrovirus gene expression in primary erythroid cells

AbstractHuman B19 erythrovirus replicates in erythroid progenitors present in bone marrow and fetal tissues where partial oxygen tension is low. Here we show that infected human primary erythroid progenitor cells exposed to hypoxia (1% O2) in vitro increase viral capsid protein synthesis, virus replication, and virus production. Hypoxia-inducible factor-1 (HIF-1), the main transcription factor involved in the cellular response to reduced oxygenation, is shown to bind an HIF binding site (HBS) located in the distal part of the B19 promoter region, but the precise mechanism involved in the oxygen-sensitive upregulation of viral gene expression remains to be elucidated

Synthèse et transport des protéines de capside du parvovirus humain B19 dans les cellules primaires érythroïdes CD36+

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Comment on: 'Resolution of CMV Infection in the Bowel on Vedolizumab Therapy'.

To the Editor, We read with interest the case reported by Rawa-Gołębiewska et al.1 on the resolution of Cytomegalovirus [CMV] infection on vedolizumab [VZ] therapy. We experienced a similar case that adds two additional pieces of information. First, we showed that a co-treatment with ganciclovir and VZ seems safe. Second, we observed molecular evolution of CMV tissue DNA load up to 4 months following this unusual combination. [...

Comparative Evaluation of a Commercially Available Automated System for Extraction of Viral DNA from Whole Blood: Application to Monitoring of Epstein-Barr Virus and Cytomegalovirus Load ▿

The NucliSENS easyMAG automated system was compared to the column-based Qiagen method for Epstein-Barr virus (EBV) or cytomegalovirus (CMV) DNA extraction from whole blood before viral load determination using the corresponding R-gene amplification kits. Both extraction techniques exhibited a total agreement of 81.3% for EBV and 87.2% for CMV