title: Brincidofovir (CMX001) inhibits BK polyomavirus replication in primary human urothelial cells.
abstract: BK 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 (EC50 and 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 (SI50 and 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.
authors: Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway Department of Medical Biology, UiT The Arctic University of Norway, Tromsø, Norway.
authors: Garth D
authors: GD
authors: Tylden
authors: Transplantation & Clinical Virology, Department Biomedicine (Haus Petersplatz), University of Basel, Basel, Switzerland Infectious Diseases & Hospital Epidemiology, University Hospital Basel, Basel, Switzerland.
authors: Hans H
authors: HH
authors: Hirsch
authors: Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway Metabolic and Renal Research Group, UiT The Arctic University of Norway, Tromsø, Norway christine.rinaldo@unn.no.
authors: Christine Hanssen
authors: http://orcid.org/0000-0002-6970-6728
authors: CH
authors: Rinaldo
mesh_terms: D000998:Antiviral Agents / Q000009:adverse effects / Q000494:pharmacology; D001739:BK Virus / Q000187:drug effects* / Q000502:physiology; D015153:Blotting, Western; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003596:Cytosine / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000494:pharmacology; D006801:Humans; D063065:Organophosphonates / Q000009:adverse effects / Q000494:pharmacology*; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D000998:Antiviral Agents; D063065:Organophosphonates; C525733:brincidofovir; D003596:Cytosine