scholarly journals Brincidofovir (CMX001) Inhibits BK Polyomavirus Replication in Primary Human Urothelial Cells

2015 ◽  
Vol 59 (6) ◽  
pp. 3306-3316 ◽  
Author(s):  
Garth D. Tylden ◽  
Hans H. Hirsch ◽  
Christine Hanssen Rinaldo
Keyword(s):  
Hemorrhagic Cystitis ◽  
Membrane Integrity ◽  
Mitochondrial Activity ◽  
Target Cells ◽  
Urothelial Cells ◽  
Late Gene Expression ◽  
Cytotoxic Effects ◽  
Hematopoietic Stem ◽  
Bk Polyomavirus ◽  
Renal Tubule Cell

ABSTRACTBK polyomavirus (BKPyV)-associated hemorrhagic cystitis (PyVHC) complicates 5 to 15% of allogeneic hematopoietic stem cell transplantations. Targeted antivirals are still unavailable. Brincidofovir (BCV; previously CMX001) has shown inhibitory activity against diverse viruses, including BKPyV in a primary human renal tubule cell culture model of polyomavirus-associated nephropathy. We investigated the effects of BCV in BKPyV-infected and uninfected primary human urothelial cells (HUCs), the target cells of BKPyV in PyVHC. The BCV concentrations causing 50 and 90% reductions (EC50and EC90) in the number of intracellular BKPyV genome equivalents per cell (icBKPyV) were 0.27 μM and 0.59 μM, respectively. At 0.63 μM, BCV reduced viral late gene expression by 90% and halted progeny release. Preinfection treatment for only 24 h reduced icBKPyV similarly to treatment from 2 to 72 h postinfection, while combined pre- and postinfection treatment suppressed icBKPyV completely. After investigating BCV's effects on HUC viability, mean selectivity indices at 50 and 90% inhibition (SI50and SI90) calculated for cellular DNA replication were 2.7 and 2.9, respectively, those for mitochondrial activity were 8.9 and 10.4, those for total ATP were 8.6 and 8.2, and those for membrane integrity were 25.9 and 16.7. The antiviral and cytostatic effects, but less so the cytotoxic effects, were inversely related to cell density. The cytotoxic effects at concentrations of ≥10 μM were rapid and likely related to BCV's lipid moiety. After carefully defining the antiviral, cytostatic, and cytotoxic properties of BCV in HUCs, we conclude that a preemptive or prophylactic approach in PyVHC is likely to give the best results.

scholarly journals Control of archetype BK polyomavirus miRNA expression

2020 ◽  
Author(s):  
Wei Zou ◽  
Gau Shoua Vue ◽  
Benedetta Assetta ◽  
Heather Manza ◽  
Walter J. Atwood ◽  
...  
Keyword(s):  
Hemorrhagic Cystitis ◽  
Antigen Expression ◽  
Marrow Transplant ◽  
T Antigen ◽  
Replication Capacity ◽  
Late Gene Expression ◽  
Cis Acting ◽  
Transplant Patients ◽  
Bk Polyomavirus ◽  
Dna Replication Origin

AbstractBK polyomavirus (BKPyV) is a ubiquitous human pathogen, with over 80% of adults worldwide persistently infected. BKPyV infection is usually asymptomatic in healthy people; however, it causes polyomavirus-associated nephropathy in renal transplant patients and hemorrhagic cystitis in bone marrow transplant patients. BKPyV has a circular, double-stranded DNA genome that is divided genetically into three parts: an early region, a late region, and a non-coding control region (NCCR). The NCCR contains the viral DNA replication origin and cis-acting elements regulating viral early and late gene expression. It was previously shown that a BKPyV miRNA expressed from the late strand regulates viral large T antigen expression and limits the replication capacity of archetype BKPyV. A major unanswered question in the field is how expression of the viral miRNA is regulated. Typically, miRNA is expressed from introns in cellular genes but there is no intron readily apparent in the BKPyV from which the miRNA could derive. Here we provide evidence for primary RNA transcripts that circle the genome more than once and include the NCCR. We identified splice junctions resulting from splicing of primary transcripts circling the genome more than once, and Sanger sequencing of RT-PCR products indicates that there are viral transcripts that circle the genome up to four times. Our data suggest that the miRNA is expressed from the intron of these greater-than-genome size primary transcripts.

scholarly journals BK Polyomavirus: Clinical Aspects, Immune Regulation, and Emerging Therapies

2017 ◽  
Vol 30 (2) ◽  
pp. 503-528 ◽  
Author(s):  
George R. Ambalathingal ◽  
Ross S. Francis ◽  
Mark J. Smyth ◽  
Corey Smith ◽  
Rajiv Khanna
Keyword(s):  
Hemorrhagic Cystitis ◽  
Management Strategies ◽  
Antiviral Agents ◽  
Diagnostic Tools ◽  
Clinical Aspects ◽  
Hematopoietic Stem ◽  
Renal Tubular Cells ◽  
Bk Polyomavirus ◽  
Renal Tubular ◽  
Host Virus Interactions

SUMMARY BK polyomavirus (BKV) causes frequent infections during childhood and establishes persistent infections within renal tubular cells and the uroepithelium, with minimal clinical implications. However, reactivation of BKV in immunocompromised individuals following renal or hematopoietic stem cell transplantation may cause serious complications, including BKV-associated nephropathy (BKVAN), ureteric stenosis, or hemorrhagic cystitis. Implementation of more potent immunosuppression and increased posttransplant surveillance has resulted in a higher incidence of BKVAN. Antiviral immunity plays a crucial role in controlling BKV replication, and our increasing knowledge about host-virus interactions has led to the development of improved diagnostic tools and clinical management strategies. Currently, there are no effective antiviral agents for BKV infection, and the mainstay of managing reactivation is reduction of immunosuppression. Development of immune-based therapies to combat BKV may provide new and exciting opportunities for the successful treatment of BKV-associated complications.

scholarly journals Acitretin and Retinoic Acid Derivatives Inhibit BK Polyomavirus Replication in Primary Human Proximal Renal Tubular Epithelial and Urothelial Cells

2021 ◽  
Author(s):  
Zongsong Wu ◽  
Fabrice E Graf ◽  
Hans H. Hirsch
Keyword(s):  
Retinoic Acid ◽  
Protein Expression ◽  
Hemorrhagic Cystitis ◽  
Vero Cells ◽  
T Antigen ◽  
Large T Antigen ◽  
Urothelial Cells ◽  
Sv40 Large T Antigen ◽  
Treatment And Prevention ◽  
Bk Polyomavirus

Small-molecule drugs inhibiting BK polyomavirus (BKPyV) represent a significant unmet clinical need in view of polyomavirus-associated nephropathy or hemorrhagic cystitis which complicate 5% to 25% of kidney and hematopoietic cell transplantations. We characterized the inhibitory activity of acitretin on BKPyV-replication in primary human renal proximal tubular epithelial cells (RPTECs). Effective inhibitory concentration 50% (EC50) and 90% (EC90) were determined in dilution series measuring BKPyV loads, transcripts and protein expression, using cell proliferation, metabolic activity, and viability to estimate cytotoxic concentrations and selectivity indices (SI). Acitretin EC50 and EC90 in RPTECs were 0.64 (SI50 250) and 3.25 μM (SI90 49.2), respectively. Acitretin effectively inhibited BKPyV-replication until 72 h post-infection when added 24 h before until 12 h after infection, but decreased to <50% at later timepoints. Acitretin did not interfere with nuclear delivery of BKPyV genomes, but decreased large T-antigen transcription and protein expression. Acitretin did not inhibit the initial round of BKPyV-replication following transfection of full-length viral genomes, but affected subsequent rounds of re-infection. Acitretin also inhibited BKPyV-replication in human urothelial cells and in Vero cells, but not in COS-7 cells constitutively expressing SV40-large T-antigen. Retinoic acid-agonists (all-trans-retinoic acid, 9-cis-RA, 13-cis-RA, bexarotene, tamibarotene) and the RAR/RXR-antagonist RO41-5253 also inhibited BKPyV-replication, pointing to as yet undefined mechanism. Importance Acitretin selectively inhibits BKPyV-replication in primary human cell culture models of nephropathy and hemorrhagic cystitis. Since acitretin is an approved drug in clinical use reaching BKPyV-inhibiting concentrations in systemically treated patients, further studies are warranted to provide data for clinical repurposing of retinoids for treatment and prevention of replicative BKPyV-diseases.

scholarly journals Evaluation of a panel of spermatological methods for assessing reprotoxic compounds in multilayer semen plastic bags

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
M. Schulze ◽  
F. Schröter ◽  
M. Jung ◽  
U. Jakop
Keyword(s):  
Membrane Integrity ◽  
Diglycidyl Ether ◽  
Mitochondrial Activity ◽  
Prolonged Storage ◽  
Prolonged Incubation ◽  
Plastic Bags ◽  
Plastic Materials ◽  
Bisphenol A Diglycidyl Ether ◽  
Semen Preservation ◽  
Boar Spermatozoa

AbstractThe increase of fertility performance in sows is one of the biggest achievements in pig production over the last 30 years. Nevertheless, pig farms using artificial insemination (AI) repeatedly experienced in recent year’s fertility problems with dramatic consequences due to toxic compounds from plastic semen bags. In particular, bisphenol A diglycidyl-ether (BADGE) present in multilayer plastic bags can leach into the semen and could affect the functionality of the spermatozoa. Former studies could not find any alterations in spermatozoa based on the exposure to BADGE. The aim of the study was to evaluate effects of BADGE on boar spermatozoa using an extended panel of spermatological methods. In spring 2019, a large drop in farrowing rates from 92.6 ± 2.3% to 63.7 ± 11.1% in four sow farms in Croatia was detected. In migration studies, BADGE could be identified as a causal toxic compound and leached into the extended semen in concentration of 0.37 ± 0.05 mg/L. Detailed spermatological studies showed that significant predictors for effects on spermatozoa were different levels of motility and kinematic data after a prolonged storage time, thermo-resistance test (prolonged incubation time), mitochondrial activity, membrane integrity and fluidity. No serious effects were observed for sperm morphology and DNA fragmentation. These results provide new insights into the development of a new quality assurance concept for a detailed spermatological examination during testing of plastic materials for boar semen preservation. It could be shown that boar spermatozoa are an excellent biosensor to detect potential toxicity and fertility-relevant compounds.

scholarly journals IL-6 blocks a discrete early step in lymphopoiesis

Blood ◽  
2005 ◽  
Vol 106 (3) ◽  
pp. 879-885 ◽  
Author(s):  
Kazuhiko Maeda ◽  
Yoshihiro Baba ◽  
Yoshinori Nagai ◽  
Kozo Miyazaki ◽  
Alexander Malykhin ◽  
...  
Keyword(s):  
Target Cells ◽  
Hematopoietic Progenitors ◽  
Early Step ◽  
Hematopoietic Stem ◽  
Lymphoid Lineage ◽  
Src Homology 2 ◽  
Multipotent Progenitors ◽  
Src Homology ◽  
Src Homology 2 Domain

Abstract Animals lacking Src homology 2 domain-containing inositol 5-phosphatase (SHIP) display a reduction in lymphopoiesis and a corresponding enhancement of myelopoiesis. These effects are mediated at least in part by elevated levels of interleukin 6 (IL-6). Here, we show the lymphopoiesis block in SHIP–/– mice is due to suppression of the lymphoid lineage choice by uncommitted progenitors. The suppression can be reproduced in vitro with recombinant IL-6, and IL-6 acts directly on hematopoietic progenitors. The block is partially overcome in SHIP–/– IL-6–/– double-deficient animals. IL-6 does not suppress but actually enhances proliferation of lymphoid-committed progenitors, indicating the IL-6 target cells are hematopoietic stem cells or multipotent progenitors. The findings suggest a mechanism for the lymphopenia that accompanies proinflammatory diseases.

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