Parvovirus B19 (B19V) is a human ssDNA virus responsible for a wide range of clinical manifestations, still lacking for a specific antiviral therapy. The identification of compounds active against B19V may add therapeutic options to the treatment of B19V infections. To this purpose, focus was raised to cidofovir (CDV), an acyclic nucleoside phosphonate broadly active against dsDNA viruses. Two model systems were used to assess the inhibitory effect of CDV on B19V replication: 1) the UT7/EpoS1 megakaryoblastoid cell line, able to support B19V DNA replication; 2) the ex vivo expanded CD36+ erythroid progenitor cells (EPCs), a highly permissive system for B19V replication and expression. EPCs were generated from peripheral blood, via culture in a medium containing erythropoietic growth factors (EPO, SCF and Il-3), for up to 18 days. Expression of EPC differentiation markers ranged from a minimum of 10% at 3-day to a 80% at 15-day culturing. Infection at different stages indicated that the EPC system was fully permissive to B19V between days 6 and 15 of EPCs in vitro growth and differentiation. Experiments were carried out at different multiplicity of infection (100 – 104 genomes/cell) and CDV concentrations (0.1 – 500 μM). The effects of CDV were evaluated by its capacity to inhibit viral nucleic acid synthesis, as determined by means of q PCR assays for quantification of viral nucleic acids. CDV showed a dose-dependent inhibiting activity on B19V replication within infected UT7/ EpoS1, allowing for the determination of EC50 and EC90 values (7.45–41.27 μM, and 84.73–360.7 μM, respectively). In EPCs, a significant reduction on B19V DNA amounts was obtained only at 500 μM (68.2–92.8%). However, cell-culture supernatants from B19V-infected, CDV-treated EPCs were used for serial infection of EPCs in the presence of CDV, leading to a progressive inhibition of B19V replication compared to untreated controls. With regard to the host cells, the drug did not interfere with the overall cellular DNA replication and metabolic activity. The effect of CDV on B19V could be likely related to a specific inhibition on the viral replication process, indicating the possibility of developing an antiviral strategy against a relevant human pathogenic virus.
Bua, G., Bonvicini, F., Manaresi, E., Gallinella, G. (2015). Inhibitory effect of Cidofovir on Parvovirus B19 replication.
Inhibitory effect of Cidofovir on Parvovirus B19 replication
BUA, GLORIA;BONVICINI, FRANCESCA;MANARESI, ELISABETTA;GALLINELLA, GIORGIO
2015
Abstract
Parvovirus B19 (B19V) is a human ssDNA virus responsible for a wide range of clinical manifestations, still lacking for a specific antiviral therapy. The identification of compounds active against B19V may add therapeutic options to the treatment of B19V infections. To this purpose, focus was raised to cidofovir (CDV), an acyclic nucleoside phosphonate broadly active against dsDNA viruses. Two model systems were used to assess the inhibitory effect of CDV on B19V replication: 1) the UT7/EpoS1 megakaryoblastoid cell line, able to support B19V DNA replication; 2) the ex vivo expanded CD36+ erythroid progenitor cells (EPCs), a highly permissive system for B19V replication and expression. EPCs were generated from peripheral blood, via culture in a medium containing erythropoietic growth factors (EPO, SCF and Il-3), for up to 18 days. Expression of EPC differentiation markers ranged from a minimum of 10% at 3-day to a 80% at 15-day culturing. Infection at different stages indicated that the EPC system was fully permissive to B19V between days 6 and 15 of EPCs in vitro growth and differentiation. Experiments were carried out at different multiplicity of infection (100 – 104 genomes/cell) and CDV concentrations (0.1 – 500 μM). The effects of CDV were evaluated by its capacity to inhibit viral nucleic acid synthesis, as determined by means of q PCR assays for quantification of viral nucleic acids. CDV showed a dose-dependent inhibiting activity on B19V replication within infected UT7/ EpoS1, allowing for the determination of EC50 and EC90 values (7.45–41.27 μM, and 84.73–360.7 μM, respectively). In EPCs, a significant reduction on B19V DNA amounts was obtained only at 500 μM (68.2–92.8%). However, cell-culture supernatants from B19V-infected, CDV-treated EPCs were used for serial infection of EPCs in the presence of CDV, leading to a progressive inhibition of B19V replication compared to untreated controls. With regard to the host cells, the drug did not interfere with the overall cellular DNA replication and metabolic activity. The effect of CDV on B19V could be likely related to a specific inhibition on the viral replication process, indicating the possibility of developing an antiviral strategy against a relevant human pathogenic virus.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
