Prodrug Strategies for the Development of β-l-5-(()-2-Bromovinyl)-1-((2,4)-2-(hydroxymethyl)-1,3-(dioxolane-4-yl))uracil (l-BHDU) against Varicella Zoster Virus (VZV).

Varicella zoster virus (VZV) establishes lifelong infection after primary disease and can reactivate. Several drugs are approved to treat VZV diseases, but new antivirals with greater potency are needed. Previously, we identified β-l-5-((-2-bromovinyl)-1-((2,4)-2-(hydroxymethyl)-1,3-(dioxolane-4-yl))uracil (l-BHDU, ), which had significant anti-VZV activity.

A Human Skin Model for Assessing Arboviral Infections.

Arboviruses such as flaviviruses and alphaviruses cause a significant human healthcare burden on a global scale. Transmission of these viruses occurs during human blood feeding at the mosquito-skin interface. Not only do pathogen immune evasion strategies influence the initial infection and replication of pathogens delivered, but arthropod salivary factors also influence transmission foci.

Development of Robust Varicella Zoster Virus Luciferase Reporter Viruses for In Vivo Monitoring of Virus Growth and Its Antiviral Inhibition in Culture, Skin, and Humanized Mice.

There is a continued need to understand varicella-zoster virus (VZV) pathogenesis and to develop more effective antivirals, as it causes chickenpox and zoster. As a human-restricted alphaherpesvirus, the use of human skin in culture and mice is critical in order to reveal the important VZV genes that are required for pathogenesis but that are not necessarily observed in the cell culture. We previously used VZV-expressing firefly luciferase (fLuc), under the control of the constitutively active SV40 promoter (VZV-BAC-Luc), to measure the VZV spread in the same sample.

Humanized Severe Combined Immunodeficient (SCID) Mouse Models for Varicella-Zoster Virus Pathogenesis.

Varicella-zoster virus (VZV) is a human-restricted virus, which raises obstacles to research. The strict human tropism limits knowledge about its pathogenesis and creates challenges for evaluating antiviral treatments and vaccines. The development of humanized mouse models was driven by the need to address these challenges.

A Novel Human Skin Tissue Model To Study Varicella-Zoster Virus and Human Cytomegalovirus.

The herpesviruses varicella-zoster virus (VZV) and human cytomegalovirus (HCMV) are endemic to humans. VZV causes varicella (chicken pox) and herpes zoster (shingles), while HCMV causes serious disease in immunocompromised patients and neonates. More effective, less toxic antivirals are needed, necessitating better models to study these viruses and evaluate antivirals.

Cellular Stress Response to Varicella-Zoster Virus Infection of Human Skin Includes Highly Elevated Interleukin-6 Expression.

Background: The infectious cycle of varicella-zoster virus (VZV) after reactivation from the dorsal root ganglia includes replication and assembly of complete enveloped virions in the human skin to cause the characteristic herpes zoster (shingles).

Methods: To pursue studies of innate immunity to VZV infection, we have adapted a fetal skin organ culture model to a human neonatal foreskin explant model.

Results: Abundant expression of VZV IE62, gE, and gC was visualized by confocal microscopy while numerous enveloped virions were observed by electron microscopy in infected skin organ cultures.

Targeting the alternative sigma factor RpoN to combat virulence in Pseudomonas aeruginosa.

Pseudomonas aeruginosa is a Gram-negative, opportunistic pathogen that infects immunocompromised and cystic fibrosis patients. Treatment is difficult due to antibiotic resistance, and new antimicrobials are needed to treat infections. The alternative sigma factor 54 (σ, RpoN), regulates many virulence-associated genes.

Erratum for Sarwar et al., GcsR, a TyrR-Like Enhancer-Binding Protein, Regulates Expression of the Glycine Cleavage System in Pseudomonas aeruginosa PAO1.

[This corrects the article DOI: 10.1128/mSphere.00020-16.

GcsR, a TyrR-Like Enhancer-Binding Protein, Regulates Expression of the Glycine Cleavage System in Pseudomonas aeruginosa PAO1.

Glycine serves as a major source of single carbon units for biochemical reactions within bacterial cells. Utilization of glycine is tightly regulated and revolves around a key group of proteins known as the glycine cleavage system (GCS). Our lab previously identified the transcriptional regulator GcsR (PA2449) as being required for catabolism of glycine in the opportunistic pathogen Pseudomonas aeruginosa PAO1.

β-l-1-[5-(E-2-bromovinyl)-2-(hydroxymethyl)-1,3-(dioxolan-4-yl)] uracil (l-BHDU) prevents varicella-zoster virus replication in a SCID-Hu mouse model and does not interfere with 5-fluorouracil catabolism.

The alphaherpesvirus varicella-zoster virus (VZV) causes chickenpox and shingles. Current treatments are acyclovir (ACV) and its derivatives, foscarnet and brivudine (BVdU). Additional antiviral compounds with increased potency and specificity are needed to treat VZV, especially to treat post-herpetic neuralgia.

Effects of varicella-zoster virus on cell cycle regulatory pathways.

Varicella-zoster virus (VZV) grows efficiently in quiescent cells in vivo and in culture, and virus infection activates cell cycle and signaling pathways without cell division. VZV ORFs have been identified that determine the tissue tropism for nondividing skin, T cells, and neurons in SCID-Hu mouse models. The normal cell cycle status of human foreskin fibroblasts was characterized and was dysregulated upon infection by VZV.

Varicella-zoster virus T cell tropism and the pathogenesis of skin infection.

Varicella-zoster virus (VZV) is a medically important human alphaherpesvirus that causes varicella and zoster. VZV initiates primary infection by inoculation of the respiratory mucosa. In the course of primary infection, VZV establishes a life-long persistence in sensory ganglia; VZV reactivation from latency may result in zoster in healthy and immunocompromised patients.

Compounds that target host cell proteins prevent varicella-zoster virus replication in culture, ex vivo, and in SCID-Hu mice.

Varicella-zoster virus (VZV) replicates in quiescent T cells, neurons, and skin cells. In cultured fibroblasts (HFFs), VZV induces host cyclin expression and cyclin-dependent kinase (CDK) activity without causing cell cycle progression. CDK1/cyclin B1 phosphorylates the major viral transactivator, and the CDK inhibitor roscovitine prevents VZV mRNA transcription.

Analysis of the functions of glycoproteins E and I and their promoters during VZV replication in vitro and in skin and T-cell xenografts in the SCID mouse model of VZV pathogenesis.

The two VZV glycoproteins, gE and gI, are encoded by genes that are designated open reading frames, ORF67 and ORF68, located in the short unique region of the VZV genome. These proteins have homologs in the other alphaherpesviruses. Like their homologues, VZV gE and gI exhibit prominent co-localization in infected cells and form heterodimers.

Cyclin-dependent kinase 1/cyclin B1 phosphorylates varicella-zoster virus IE62 and is incorporated into virions.

Varicella-zoster virus (VZV), an alphaherpesvirus restricted to humans, infects differentiated cells in vivo, including T lymphocytes, keratinocytes, and neurons, and spreads rapidly in confluent cultured dermal fibroblasts (HFFs). In VZV-infected HFFs, atypical expression of cyclins D3 and B1 occurs along with the induction of cyclin-dependent kinase (CDK) activity. A specific CDK1 inhibitor blocked VZV spread, indicating an important function for this cellular kinase in VZV replication.

Varicella-zoster virus infection of human fibroblast cells activates the c-Jun N-terminal kinase pathway.

The transcription factors ATF-2 and c-Jun are important for transactivation of varicella-zoster virus (VZV) genes. c-Jun is activated by the c-Jun N-terminal kinase (JNK), a member of the mitogen-activated protein kinase pathway that responds to stress and cytokines. To study the effects of VZV on this pathway, confluent human foreskin fibroblasts were infected with cell-associated VZV for 1 to 4 days.

Varicella-zoster virus infection of human foreskin fibroblast cells results in atypical cyclin expression and cyclin-dependent kinase activity.

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.

Replication of varicella-zoster virus in human skin organ culture.

Varicella-zoster virus (VZV) infection is restricted to humans, which hinders studies of its pathogenesis in rodent models of disease. To facilitate the study of VZV skin tropism, we developed an ex vivo system using human fetal skin organ culture (SOC). VZV replication was analyzed by plaque assay, transmission electron microscopy, and histology.

Human cytomegalovirus genes in the 15-kilobase region are required for viral replication in implanted human tissues in SCID mice.

Since animal models for studying human cytomegalovirus (HCMV) replication in vivo and pathogenesis are not available, severe combined immunodeficiency mice into which human tissues were implanted (SCID-hu mice) provide an alternative and valuable model for such studies. The HCMV clinical isolates, including those of the Toledo strain, replicate to high titers in human tissue implanted into SCID mice; however, the attenuated AD169 strain has completely lost this ability. The major difference between Toledo and AD169 is a 15-kb segment, encoding 19 open reading frames, which is present in all virulent strains but deleted from attenuated strains.

Viral and cellular kinases are potential antiviral targets and have a central role in varicella zoster virus pathogenesis.

Herpesviruses utilize viral and cellular kinases for replication, and these mediate essential functions that are important for viral pathogenesis. Elucidating the roles of kinases in herpesvirus infections may highlight virus-host interactions that are possible targets for kinase inhibitors with antiviral activity. Varicella zoster virus (VZV) encodes two kinases that phosphorylate viral proteins involved in regulation, assembly, and virulence.

Roscovitine, a cyclin-dependent kinase inhibitor, prevents replication of varicella-zoster virus.

Understanding the interactions between varicella-zoster virus (VZV) and host cells can be addressed by using small molecule inhibitors of cellular enzymes. Roscovitine (Rosco) is a purine derivative that inhibits cyclin-dependent kinase 1 (cdk1), cdk2, cdk5, cdk7, and cdk9, which are key regulators of the cell cycle and transcription. Herpesviruses are known to interact with cell cycle proteins; thus, the antiviral effects of Rosco on VZV growth were evaluated.