Effects of thyroid hormone on HSV-1 gene regulation: implications in the control of viral latency and reactivation.

Thyroid hormone (TH) is involved in many biological functions such as animal development, cell differentiation, etc. Variation and/or disruption of plasma TH level often led to abnormalities and physiological disorders. TH exerts the effects through its nuclear receptors (TR).

Lytic HSV-1 infection induces the multifunctional transcription factor Early Growth Response-1 (EGR-1) in rabbit corneal cells.

Background: Herpes simplex virus type-1 (HSV-1) infections can cause a number of diseases ranging from simple cold sores to dangerous keratitis and lethal encephalitis. The interaction between virus and host cells, critical for viral replication, is being extensively investigated by many laboratories. In this study, we tested the hypothesis that HSV-1 lytic infection triggers the expression of important multi-functional transcription factor Egr1.

Manzamine A as a novel inhibitor of herpes simplex virus type-1 replication in cultured corneal cells.

This study investigated the putative inhibitory effect of manzamine A on HSV-1 infection. Our results indicated that manzamine A effectively inhibited viral replication and infection in the cell line SIRC, a corneal cell line, at 1 µM. The existing anti-HSV-1 drug acyclovir was analyzed and showed a comparable activity at 50 µM.

Thyroid hormone controls the gene expression of HSV-1 LAT and ICP0 in neuronal cells.

Various factors/pathways including hormonal regulation have been suggested to control herpes simplex virus type 1 (HSV-1) latency and reactivation. Our computer analysis identified a DNA repeat containing thyroid hormone-responsive elements (TRE) in the regulatory region of HSV-1 latency-associated transcript (LAT). Thyroid hormone (triiodothyronine, T(3)) functions via its receptor TR (thyroid hormone receptor), a transcription factor.

Regulation of herpes simplex virus type 1 thymidine kinase gene expression by thyroid hormone receptor in cultured neuronal cells.

Herpes simplex virus type 1 (HSV-1) undergoes acute infection in epithelial cells followed by establishment of latency in the neurons of trigeminal ganglia. The latent virus maintains a dormant state and can recurs spontaneously, suggesting transcriptional silencing and reactivation occur in neurons. Computer data mining identified a nuclear hormone response element (NRE), the binding site for the thyroid hormone receptor (TR) or other nuclear hormone receptor, in the promoter of HSV-1 thymidine kinase (TK).

Repressor element-1 silencing transcription factor/neuronal restrictive silencer factor (REST/NRSF) can regulate HSV-1 immediate-early transcription via histone modification.

Background: During primary infection of its human host, Herpes Simplex Virus Type-1 (HSV-1) establishes latency in neurons where the viral genome is maintained in a circular form associated with nucleosomes in a chromatin configration. During latency, most viral genes are silenced, although the molecular mechanisms responsible for this are unclear. We hypothesized that neuronal factors repress HSV-1 gene expression during latency.

Early growth response gene 1 (Egr-1) regulates HSV-1 ICP4 and ICP22 gene expression.

The molecular mechanisms mediating herpes simplex virus type 1 (HSV-1) gene silencing during latent infection are not clear. Five copies of early growth response gene 1 (Egr-1) binding elements were identified in the intron of HSV-1 ICP22 (infected cell protein No. 22) gene, leading to the hypothesis that Egr-1 binds to the viral genome and regulates the viral gene expression.