scholarly journals Differential Requirement for Cell Fusion and Virion Formation in the Pathogenesis of Varicella-Zoster Virus Infection in Skin and T Cells

2004 ◽  
Vol 78 (23) ◽  
pp. 13293-13305 ◽  
Author(s):  
Jaya Besser ◽  
Minako Ikoma ◽  
Konstanze Fabel ◽  
Marvin H. Sommer ◽  
Leigh Zerboni ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Varicella Zoster Virus ◽  
Cell Fusion ◽  
Cultured Cells ◽  
Varicella Zoster Virus Infection ◽  
Virion Assembly ◽  
Varicella Zoster ◽  
Human T Cell ◽  
Virion Formation

ABSTRACT The protein product of varicella-zoster virus (VZV) ORF47 is a serine/threonine protein kinase and tegument component. Evaluation of two recombinants of the Oka strain, rOka47ΔC, with a C-terminal truncation of ORF47, and rOka47D-N, with a point mutation in the conserved kinase motif, showed that ORF47 kinase function was necessary for optimal VZV replication in human skin xenografts in SCID mice but not in cultured cells. We now demonstrate that rOka47ΔC and rOka47D-N mutants do not infect human T-cell xenografts. Differences in the growth of kinase-defective ORF47 mutants allowed an examination of requirements for VZV pathogenesis in skin and T cells in vivo. Although virion assembly was reduced and no virion transport to cell surfaces was observed, epidermal cell fusion persisted, and VZV polykaryocytes were generated by rOka47ΔC and rOka47D-N in skin. Virion assembly was also impaired in vitro, but VZV-induced cell fusion continued to cause syncytia in cultured cells infected with rOka47ΔC or rOka47D-N. Intracellular trafficking of envelope glycoprotein E and the ORF47 and IE62 proteins, components of the tegument, was aberrant without ORF47 kinase activity. In summary, normal VZV virion assembly appears to require ORF47 kinase function. Cell fusion was induced by ORF47 mutants in skin, and cell-cell spread occurred even though virion formation was deficient. VZV-infected T cells do not undergo cell fusion, and impaired virion assembly by ORF47 mutants was associated with a complete elimination of T-cell infectivity. These observations suggest a differential requirement for cell fusion and virion formation in the pathogenesis of VZV infection in skin and T cells.

scholarly journals T-Cell Tropism and the Role of ORF66 Protein in Pathogenesis of Varicella-Zoster Virus Infection

2005 ◽  
Vol 79 (20) ◽  
pp. 12921-12933 ◽  
Author(s):  
Anne Schaap ◽  
Jean-Francois Fortin ◽  
Marvin Sommer ◽  
Leigh Zerboni ◽  
Shaye Stamatis ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Protein Expression ◽  
Varicella Zoster Virus ◽  
Stop Codon ◽  
Varicella Zoster Virus Infection ◽  
Cell Tropism ◽  
Varicella Zoster ◽  
Efficient Replication

ABSTRACT The pathogenesis of varicella-zoster virus (VZV) involves a cell-associated viremia during which infectious virus is carried from sites of respiratory mucosal inoculation to the skin. We now demonstrate that VZV infection of T cells is associated with robust virion production and modulation of the apoptosis and interferon pathways within these cells. The VZV serine/threonine protein kinase encoded by ORF66 is essential for the efficient replication of VZV in T cells. Preventing ORF66 protein expression by stop codon insertion (pOka66S) impaired the growth of the parent Oka (pOka) strain in T cells in SCID-hu T-cell xenografts in vivo and reduced formation of VZV virions. The lack of ORF66 protein also increased the susceptibility of infected T cells to apoptosis and reduced the capacity of the virus to interfere with induction of the interferon (IFN) signaling pathway following exposure to IFN-γ. However, preventing ORF66 protein expression only slightly reduced growth in melanoma cells in culture and did not diminish virion formation in these cells. The pOka66S virus showed only a slight defect in growth in SCID-hu skin implants compared with intact pOka. These observations suggest that the ORF66 kinase plays a unique role during infection of T cells and supports VZV T-cell tropism by contributing to immune evasion and enhancing survival of infected T cells.

scholarly journals Dissecting the Molecular Mechanisms of the Tropism of Varicella-Zoster Virus for Human T Cells

2016 ◽  
Vol 90 (7) ◽  
pp. 3284-3287 ◽  
Author(s):  
Nandini Sen ◽  
Ann M. Arvin
Keyword(s):  
T Cells ◽  
T Cell ◽  
Varicella Zoster Virus ◽  
Molecular Mechanisms ◽  
Cell Mass ◽  
Surface Proteins ◽  
Reading Frame ◽  
Varicella Zoster ◽  
Human T Cells ◽  
Skin Homing

Studies of varicella-zoster virus (VZV) tropism for T cells support their role in viral transport to the skin during primary infection. Multiparametric single-cell mass cytometry demonstrates that, instead of preferentially infecting skin-homing T cells, VZV alters cell signaling and remodels surface proteins to enhance T cell skin trafficking. Viral proteins dispensable in skin, such as that encoded by open reading frame 66, are necessary in T cells. Interference with VZV T cell tropism may offer novel strategies for drug and vaccine design.

scholarly journals Tropism of Varicella-Zoster Virus for Human Tonsillar CD4+ T Lymphocytes That Express Activation, Memory, and Skin Homing Markers

2002 ◽  
Vol 76 (22) ◽  
pp. 11425-11433 ◽  
Author(s):  
Chia-Chi Ku ◽  
Jorge A. Padilla ◽  
Charles Grose ◽  
Eugene C. Butcher ◽  
Ann M. Arvin
Keyword(s):  
T Cells ◽  
T Cell ◽  
Varicella Zoster Virus ◽  
T Cell Activation ◽  
Cell Activation ◽  
Surface Proteins ◽  
Upper Respiratory Tract ◽  
Varicella Zoster ◽  
Skin Homing ◽  
Chemokine Receptor 4

ABSTRACT Varicella-zoster virus (VZV) is an alphaherpesvirus with the characteristic neurotropism of this group, but VZV also infects T cells productively and downregulates major histocompatibility complex (MHC) class I expression on infected T cells, as shown in the SCID-hu mouse model. T-cell tropism is likely to be critical for the cell-associated viremia associated with primary VZV infection. In these experiments, we found that VZV infects human tonsillar CD4+ T cells in culture, with 15 to 25% being positive for VZV proteins as detected by polyclonal anti-VZV immunoglobulin G (IgG) staining and monitored by flow cytometry analysis. RNA transcripts for VZV gE, a late gene product, were detected in T-cell populations that expressed VZV surface proteins, but not in the VZV-negative cell fraction. Exposure to phorbol myristate acetate resulted in an increase in VZV-positive T cells, indicating that viral DNA was present within these cells and that VZV gene expression could be induced by T-cell activation. By immune scanning electron microscopy, VZV virions were detected in abundance on the surfaces of infected tonsillar T cells. The predominant CD4+ T-lymphocyte subpopulations that became infected were activated CD69+ T cells with the CD45RA− memory phenotype. Subsets of CD4+ T cells that expressed skin homing markers, cutaneous leukocyte antigen, and chemokine receptor 4 were also infected with VZV. By chemotaxis assay, VZV-infected T cells migrated to SDF-1, demonstrating that skin migratory function was intact despite VZV infection. The susceptibility of tonsil T cells to VZV suggests that these cells may be important targets during the initial VZV infection of upper respiratory tract sites. Viral transfer to migrating T cells in the tonsils may facilitate cell-associated viremia, and preferential infection of CD4 T cells that express skin homing markers may enhance VZV transport to cutaneous sites of replication.

scholarly journals ORF66 Protein Kinase Function Is Required for T-Cell Tropism of Varicella-Zoster Virus In Vivo

2006 ◽  
Vol 80 (23) ◽  
pp. 11806-11816 ◽  
Author(s):  
Anne Schaap-Nutt ◽  
Marvin Sommer ◽  
Xibing Che ◽  
Leigh Zerboni ◽  
Ann M. Arvin
Keyword(s):  
T Cells ◽  
T Cell ◽  
Protein Kinase ◽  
Varicella Zoster Virus ◽  
Kinase Domain ◽  
Cell Surface Expression ◽  
Cell Tropism ◽  
Varicella Zoster ◽  
Protein Functions

ABSTRACT Several functions have been attributed to the serine/threonine protein kinase encoded by open reading frame 66 (ORF66) of varicella-zoster virus (VZV), including modulation of the apoptosis and interferon pathways, down-regulation of major histocompatibility complex class I cell surface expression, and regulation of IE62 localization. The amino acid sequence of the ORF66 protein contains a recognizable conserved kinase domain. Point mutations were introduced into conserved protein kinase motifs to evaluate their importance to ORF66 protein functions. Two substitution mutants were generated, including a G102A substitution, which blocked autophosphorylation and altered IE62 localization, and an S250P substitution, which had no effect on either autophosphorylation or IE62 localization. Both kinase domain mutants grew to titers equivalent to recombinant parent Oka (pOka) in vitro. pOka66G102A had slightly reduced growth in skin, which was comparable to the reduction observed when ORF66 translation was prevented by stop codon insertions in pOka66S. In contrast, infection of T-cell xenografts with pOka66G102A was associated with a significant decrease in infectious virus production equivalent to the impaired T-cell tropism found with pOka66S infection of T-cell xenografts in vivo. Disrupting kinase activity with the G102A mutation did not alter IE62 cytoplasmic localization in VZV-infected T cells, suggesting that decreased T-cell tropism is due to other ORF66 protein functions. The G102A mutation reduced the antiapoptotic effects of VZV infection of T cells. These experiments indicate that the T-cell tropism of VZV depends upon intact ORF66 protein kinase function.

scholarly journals Varicella-Zoster Virus Infection of Human Foreskin Fibroblast Cells Results in Atypical Cyclin Expression and Cyclin-Dependent Kinase Activity

2006 ◽  
Vol 80 (11) ◽  
pp. 5577-5587 ◽  
Author(s):  
Stacey A. Leisenfelder ◽  
Jennifer F. Moffat
Keyword(s):  
Cell Cycle ◽  
Varicella Zoster Virus ◽  
Cultured Cells ◽  
Cyclin B1 ◽  
Human Infection ◽  
Dermal Fibroblasts ◽  
Cyclin D3 ◽  
Varicella Zoster Virus Infection ◽  
Varicella Zoster ◽  
Protein Levels

ABSTRACT In its course of human infection, varicella-zoster virus (VZV) infects rarely dividing cells such as dermal fibroblasts, differentiated keratinocytes, mature T cells, and neurons, none of which are actively synthesizing DNA; however, VZV is able to productively infect them and use their machinery to replicate the viral genome. We hypothesized that VZV alters the intracellular environment to favor viral replication by dysregulating cell cycle proteins and kinases. Cyclin-dependent kinases (CDKs) and cyclins displayed a highly unusual profile in VZV-infected confluent fibroblasts: total amounts of CDK1, CDK2, cyclin B1, cyclin D3, and cyclin A protein increased, and kinase activities of CDK2, CDK4, and cyclin B1 were strongly and simultaneously induced. Cyclins B1 and D3 increased as early as 24 h after infection, concurrent with VZV protein synthesis. Confocal microscopy indicated that cyclin D3 overexpression was limited to areas of IE62 production, whereas cyclin B1 expression was irregular across the VZV plaque. Downstream substrates of CDKs, including pRb, p107, and GM130, did not show phosphorylation by immunoblotting, and p21 and p27 protein levels were increased following infection. Finally, although the complement of cyclin expression and high CDK activity indicated a progression through the S and G2 phases of the cell cycle, DNA staining and flow cytometry indicated a possible G1/S blockade in infected cells. These data support earlier studies showing that pharmacological CDK inhibitors can inhibit VZV replication in cultured cells.

scholarly journals Varicella-Zoster Virus Infection of a Human CD4-Positive T-Cell Line

Virology ◽  
2000 ◽  
Vol 270 (2) ◽  
pp. 278-285 ◽  
Author(s):  
Leigh Zerboni ◽  
Marvin Sommer ◽  
Carl F. Ware ◽  
Ann M. Arvin
Keyword(s):  
T Cell ◽  
Virus Infection ◽  
Varicella Zoster Virus ◽  
Cell Line ◽  
Varicella Zoster Virus Infection ◽  
Varicella Zoster
Sign in / Sign up

Export Citation Format

Share Document