Cidofovir Inhibits Genome Encapsidation and Affects Morphogenesis during the Replication of Vaccinia Virus

Jesus, Desyreé Murta; Costa, Lucas Teixeira; Gonçalves, Daniela Leão; Achete, Carlos A.; Attias, Márcia; Moussatché, Nissin; Damaso, Clarissa R.

doi:10.1128/jvi.01061-09

Cited by 19 publications

(14 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, some Cts2 virus IV particles appeared to have double membranes (Fig. 8C), a characteristic also observed in other studies in which viral morphogenesis was blocked (50,51). Together, these results suggest that the initial steps of viral particle assembly are not affected by the lack of the B1 protein; however, they indicate that the B1 protein is needed for the formation of IVNs in U2OS cells.…”

Section: Depletion Of Endogenous Baf Shows No Impact On Cts2 Virus Prsupporting

confidence: 47%

Vaccinia Virus B1 Kinase Is Required for Postreplicative Stages of the Viral Life Cycle in a BAF-Independent Manner in U2OS Cells

Jamin

Ibrahim

Wicklund

et al. 2015

J Virol

View full text Add to dashboard Cite

The vaccinia virus B1R gene encodes a highly conserved protein kinase that is essential for the poxviral life cycle. As demonstrated in many cell types, B1 plays a critical role during viral DNA replication when it inactivates the cellular host defense effector barrier to autointegration factor (BAF or BANF1). To better understand the role of B1 during infection, we have characterized the growth of a B1-deficient temperature-sensitive mutant virus (Cts2 virus) in U2OS osteosarcoma cells. In contrast to all other cell lines tested to date, we found that in U2OS cells, Cts2 viral DNA replication is unimpaired at the nonpermissive temperature. However, the Cts2 viral yield in these cells was reduced more than 10-fold, thus indicating that B1 is required at another stage of the vaccinia virus life cycle. Our results further suggest that the host defense function of endogenous BAF may be absent in U2OS cells but can be recovered through either overexpression of BAF or fusion of U2OS cells with mouse cells in which the antiviral function of BAF is active. Interestingly, examination of late viral proteins during Cts2 virus infection demonstrated that B1 is required for optimal processing of the L4 protein. Finally, execution point analyses as well as electron microscopy studies uncovered a role for B1 during maturation of poxviral virions. Overall, this work demonstrates that U2OS cells are a novel model system for studying the cell type-specific regulation of BAF and reveals a role for B1 beyond DNA replication during the late stages of the viral life cycle. IMPORTANCEThe most well characterized role for the vaccinia virus B1 kinase is to facilitate viral DNA replication by phosphorylating and inactivating BAF, a cellular host defense responsive to foreign DNA. Additional roles for B1 later in the viral life cycle have been postulated for decades but are difficult to examine directly due to the importance of B1 during DNA replication. Here, we demonstrate that in U2OS cells, a B1 mutant virus escapes the block in DNA replication observed in other cell types and, instead, this mutant virus exhibits impaired late protein accumulation and incomplete maturation of new virions. These data provide the clearest evidence to date that B1 is needed for multiple critical junctures in the poxviral life cycle in a manner that is both dependent on and independent of BAF. Viral DNA replication is orchestrated by a number of early proteins, including the catalytic subunit of the viral DNA polymerase (the product of the viral E9 gene) (3-6), a heterodimeric processivity factor (A20/D4) (7-9), a single-stranded DNA (ssDNA)-binding protein (I3) (10, 11), a DNA-independent nucleotide triphosphatase (D5) (12-14), a putative scaffolding protein (H5) (15), and a serine/threonine protein kinase (B1) (6,(16)(17)(18). B1 is highly conserved within the members of the Poxviridae family that infect mammals, with the only exceptions being the Molluscipox and Parapox genera (19). It is well established that the vaccinia virus B1 protein kin...

show abstract

Section: Depletion Of Endogenous Baf Shows No Impact On Cts2 Virus Prsupporting

confidence: 47%

Vaccinia Virus B1 Kinase Is Required for Postreplicative Stages of the Viral Life Cycle in a BAF-Independent Manner in U2OS Cells

Jamin

Ibrahim

Wicklund

et al. 2015

J Virol

View full text Add to dashboard Cite

show abstract

“…1). It is also active against all of the orthopoxviruses that have been tested (Jordan et al, 2010). It was also highly effective in preventing mortality or disease in animals infected with vaccinia, cowpox, ectromelia or monkeypox viruses when given orally (Quenelle et al, 2007a; Yang et al, 2005).…”

Section: Background and Rationalementioning

confidence: 99%

“…It was also highly effective in preventing mortality or disease in animals infected with vaccinia, cowpox, ectromelia or monkeypox viruses when given orally (Quenelle et al, 2007a; Yang et al, 2005). This compound has also proven to be well tolerated in Phase I/II clinical studies and its development has been reviewed recently (Jordan et al, 2010). …”

Section: Background and Rationalementioning

confidence: 99%

Orthopoxvirus targets for the development of new antiviral agents

Prichard

Kern

2012

Antiviral Research

View full text Add to dashboard Cite

Investments in the development of new drugs for orthopoxvirus infections have fostered new avenues of research, provided an improved understanding of orthopoxvirus biology and yielded new therapies that are currently progressing through clinical trials. These broad-based efforts have also resulted in the identification of new inhibitors of orthopoxvirus replication that target many different stages of viral replication cycle. This review will discuss progress in the development of new anti-poxvirus drugs and the identification of new molecular targets that can be exploited for the development of new inhibitors. The prototype of the orthopoxvirus group is vaccinia virus and its replication cycle will be discussed in detail noting specific viral functions and their associated gene products that have the potential to serve as new targets for drug development. Progress that has been achieved in recent years should yield new drugs for the treatment of these infections and might also reveal new approaches for antiviral drug development with other viruses.

show abstract

“…Of note, infectious-progeny production was inhibited at a lower BCV concentration than BKPyV DNA replication. A possible potentiating factor could be major structural derangements of the viral genome inhibiting its packaging, as shown for poxvirus in CDV-treated cells (40). Furthermore, progeny genomes produced in the presence of CDVpp may be poor templates for further replication, as template-incorporated CDV has been shown to inhibit the viral polymerase in both CMV and vaccinia virus (13,41).…”

Section: Discussionmentioning

confidence: 99%

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

Tylden

Hirsch

Rinaldo

2015

Antimicrob Agents Chemother

View full text Add to dashboard Cite

e 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 (EC 50 and EC 90 ) in the number of intracellular BKPyV genome equivalents per cell (icBKPyV) were 0.27 M and 0.59 M, respectively. At 0.63 M, 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 (SI 50 and SI 90 ) 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 M 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.T he ubiquitous and usually quiescent BK polyomavirus (BKPyV) causes polyomavirus-associated nephropathy (PyVAN) and hemorrhagic cystitis (PyVHC) following kidney and hematopoietic stem cell transplantation (HSCT), respectively (1).PyVHC afflicts 5 to 15% of HSCT patients after engraftment (2-5). The pathogenesis of PyVHC is incompletely characterized but is believed to involve initial iatrogenic damage to the bladder mucosa during pretransplantation conditioning, which is subsequently aggravated by lytic BKPyV replication in urothelial cells in the absence of immune surveillance. This leads to exposure of both viral and host epitopes to the foreign, engrafting lymphoid cells and may contribute to graft-versus-host disease (GVHD) (6-10). Inflammation and the resultant denudation of the urothelium cause hemorrhagic cystitis ranging from microhematuria to macrohematuria, clot-related urinary retention, and postrenal failure (reviewed in reference 5).PyVAN occurs in transplanted kidneys in 1 to 10% of recipients and often results in graft loss via a combination of lytic and inflammatory destruction of the renal parenchyma (2, 5). The initial reactivation signal is unknown, but mathematical modeling supports initial reactivation in the tubular epithelial compartment, followed by viral efflux with amplification in the uroth...

show abstract

Cidofovir Inhibits Genome Encapsidation and Affects Morphogenesis during the Replication of Vaccinia Virus

Cited by 19 publications

References 56 publications

Vaccinia Virus B1 Kinase Is Required for Postreplicative Stages of the Viral Life Cycle in a BAF-Independent Manner in U2OS Cells

Vaccinia Virus B1 Kinase Is Required for Postreplicative Stages of the Viral Life Cycle in a BAF-Independent Manner in U2OS Cells

Orthopoxvirus targets for the development of new antiviral agents

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

Contact Info

Product

Resources

About