Pathogenesis Of Herpes Simplex Keratitis Research Articles

Herpes simplex virus 1 targets IRF7 via ICP0 to limit type I IFN induction

Herpes simplex keratitis (HSK), caused by herpes simplex virus type 1 (HSV-1) infection, is the commonest cause of infectious blindness in the developed world. Following infection the virus is initially suspended in the tear film, where it encounters a multi-pronged immune response comprising enzymes, complement, immunoglobulins and crucially, a range of anti-viral and pro-inflammatory cytokines. However, given that HSV-1 can overcome innate immune responses to establish lifelong latency throughout a susceptible individual’s lifetime, there is significant interest in understanding the mechanisms employed by HSV-1 to downregulate the anti-viral type I interferon (IFN) mediated immune responses. This study aimed to investigate the interactions between infected cell protein (ICP)0 and key elements of the IFN pathway to identify possible novel targets that contribute to viral immune evasion. Reporter gene assays demonstrated the ability of ICP0 to inhibit type I IFN activity downstream of pathogen recognition receptors (PRRs) which are known to be involved in host antiviral defences. Further experiments identified interferon regulatory factor (IRF)7, a driver of type I IFN, as a potential target for ICP0. These findings increase our understanding of the pathogenesis of HSK and suggest IRF7 as a potential therapeutic target.

Quantitative proteomic analysis of human corneal epithelial cells infected with HSV-1

HSV-1 infection in corneal epithelium initiates the process of herpes simplex keratitis. We investigated the dynamic change of the host proteins in corneal epithelial cells infected with HSV-1 to understand the virus-host interaction. iTRAQ coupled with LC-MS/MS was applied to quantitatively analyze the protein profiles in HSV-1 infected corneal epithelial cells at 6 and 24 h post-infection (hpi), and the results were validated by multiple reaction monitoring (MRM). We also performed bioinformatic analysis to investigate the potentially important signal pathways and protein interaction networks in the host response to HSV-1 infection. We identified 292 proteins were up-regulated and 168 proteins were down-regulated at 6 hpi, while 132 proteins were up-regulated and 89 proteins were down-regulated at 24 hpi, which were validated by MRM analysis. We found the most enriched GO terms were translational initiation, cytosol, poly(A) RNA binding, mRNA splicing via spliceosome and extracellular exosome for the dysregulated proteins. KEGG pathway analysis revealed significant changes in metabolism pathway characterized by decreased tricarboxylic acid cycle activity and increased glycolysis. Proteins interaction network analysis indicated several proteins including P4HB, ACLY, HSP90AA1 and EIF4A3, might be critical proteins in the host-virus response. Our study for the first time analyzed the protein profile of HSV-1 infected primary corneal epithelial cells by quantitative proteomics. These findings help to better understand the host-virus interaction and the pathogenesis of herpes simplex keratitis.

Transcriptional Profile and Integrative Analyses of Long Noncoding RNAs in Primary Human Corneal Epithelial Cells in Response to HSV-1 Infection

ABSTRACT Purpose Long noncoding RNAs (lncRNAs) have been demonstrated to have important regulatory functions in diverse cellular processes; however, the role of lncRNAs in the pathogenesis of herpes simplex keratitis (HSK) remains poorly understood. Methods Primary human corneal epithelial cells (HCECs) were infected with herpes simplex virus-1 (HSV-1) and the total RNAs extracted from both the infected group and the mock-infected group subjected to microarray analysis to identify the differential expression of lncRNAs and mRNAs. We also performed bioinformatic analysis including gene ontology (GO) analysis, pathway analysis and co-expression network analysis. Results Compared with mock-infected group, the expression of thousands of lncRNAs and mRNAs were significantly changed, and the microarray results were validated by qRT-PCR. The most enriched GOs targeted by up-regulated transcripts were defense response, intrinsic component of plasma membrane and cytokine activity，and the most enriched GOs targeted by the down-regulated transcripts were cellular metabolic process, intracellular part and poly (A) RNA binding. Pathway analysis indicated that the most correlated pathways for up- and down-regulated transcripts were cytokine-cytokine receptor interaction and RNA transport, respectively. Conclusions Our study identified the genome-wide profile of lncRNAs and mRNAs expression in primary corneal epithelial cells with HSV-1 infection. These transcriptomic data together with subsequent bioinformatic analysis will provide us with novel clue to the insight into molecular mechanism and potential therapeutic targets of HSK. Further studies are expected to verify the potentially functional genes and pathways and explore the critical lncRNAs. Abbreviations Long noncoding RNAs: lncRNAs; herpes simplex virus-1: HSV-1; herpes simplex virus keratitis: HSK; human corneal epithelial cells: HCECs

Establishment of a novel therapeutic vector targeting the trigeminal ganglion in rats.

BackgroundIn the pathogenesis of herpes simplex keratitis, herpes simplex virus type 1 (HSV-1) infection begins in corneal epithelium cells and then progresses through the sensory nerve endings and finally travels up forward to the trigeminal ganglion (TG), where it remains as latent virus. The available anti-HSV therapies do not completely suppress the recurrence of active HSV-1 infection. The aim of this study was to establish a novel replication-defective (rd) HSV-1 (rdHSV) vector (rdHSV-interferon gamma [IFNγ]) that could effectively target the TG.MethodsRecombinant HSV-1 virus was inserted into a shuttle plasmid carrying IFNγ to establish the rdHSV-IFNγ vector. Safety was evaluated in vitro by 50% cellular cytotoxicity in transfected SH-SY5Y neuroblastoma cells and in vivo by Kaplan–Meier survival estimate and infection rate. Wistar rats were immunized with rdHSV-IFNγ to evaluate the TG targeting efficiency. Real-time polymerase chain reaction and Western blot assays were used to evaluate IFNγ mRNA and protein expression and rdHSV-IFNγ localization.ResultsThe rdHSV-IFNγ vector was successfully constructed and showed high in vitro safety and overall survival and a corneal infection rate similar to that of control rats immunized with saline (control group; P>0.05). Real-time polymerase chain reaction and immunohistochemistry assays confirmed IFNγ expression and effective TG targeting on days 14 and 21, which increased with postimmunization time. Moreover, IFNγ was expressed sufficiently in the TG tissues.ConclusionThe rdHSV-IFNγ can act as an effective gene transporting vector that carries the therapeutic genes to the TG and triggers its expression.

TNF-α Stimulates MMP-2 and MMP-9 Activities in Human Corneal Epithelial Cells via the Activation of FAK/ERK Signaling

Aims: Herpes simplex virus type-1-induced herpes simplex keratitis (HSK) is a common immunological cornea disease. While previous studies have addressed the role of tumor necrosis factor (TNF)-α and matrix metalloproteinases (MMPs) in HSK, the mechanistic link between TNF-α and MMPs in the pathogenesis of HSK remains elusive. Methods: We first established a HSK mice model and measured the levels of TNF-α, MMP-2 and MMP-9 in the corneas at different time points by ELISA. Next, we employed cultured human corneal epithelial (HCE) cells as an in vitro model and performed gelatin zymography analysis. Results: We observed that the change in the TNF-α level shared a similar pattern to that of MMP-2 and MMP-9 in the HSK mice model. Furthermore, TNF-α stimulated MMP-2 and MMP-9 activities in a dose-dependent manner, but either knockdown of focal adhesion kinase (FAK) by short interference RNA or inhibition of extracellular regulated protein kinase (ERK) by chemical inhibitor could block TNF-α-stimulated MMP-2 and MMP-9 activities in vitro. Taken together, our results provide in vivo evidence that the TNF-α level is positively correlated with MMP-2 and MMP-9 levels in a HSK model and in vitro evidence that TNF-α stimulates MMP-2 and MMP-9 activities via the activation of FAK/ERK signaling in HCE cells. Conclusions: Our findings shed new light on the pathogenesis of HSK and open up new possibility of modulating the TNF-α-FAK-ERK signaling cascade to pursue therapeutic measures for HSK.

The role of adhesion molecules ICAM-1 and VCAM-1 in herpes simplex keratitis

To elucidate the role of adhesion molecules in the pathogenesis of herpes simplex keratitis. Fifty female Balb/c mice (4~6 weeks old, 14~22 g weight) were divided into two groups randomly. Forty were infected by herpes simplex virus and the other 10 were used as normal controls. All mice were fed under the same conditions. Corneas of these mice were collected for immunohistochemical testing on day 14 and 21 after infection. ICAM-1 was mainly expressed in the basal cells of the corneal epithelia and vascular endothelia of the infected mice. A substantial amount of VCAM-1 was also expressed in the corneal vascular endothelial cells of infected mice, and was also found in inflammatory cells in the epithelial and stromal layers of the corneas. Adhesion molecules ICAM-1 and VCAM-1 were involved in the progression of herpex simplex keratitis. They may accelerate the progress of inflammation by mediating the extravsation of inflammatory cells from vessels into the infected sites.

The role of Igh-1 disparate congenic mouse T lymphocytes in the pathogenesis of herpetic stromal keratitis.

The corneal destruction associated with herpes simplex keratitis (HSK) is primarily the result of the host's immune response to herpes simplex virus type-1 (HSV-1) infection. We examined the role of T cells and T cell subsets in the pathogenesis of HSK. Naive and immune T cells and HSV-1 immune CD4+ and CD8+ subsets from Igh-1 disparate BALB/c congenic mice were adoptively transferred into athymic BALB/c nude mice, which normally do not develop HSK. The results demonstrated that while the transfer of naive T cells from either HSK-susceptible C.AL-20 (Igh-1d) or HSK-resistant C.B-17 (Igh-1b) mice had little influence on HSK development, transfer of either CD3+ or CD4+ HSV-1 immune T cells from C.AL-20 mice resulted in the development of severe HSK in all of the recipients. Transfer of the same cell populations from C.B-17 mice resulted in the development of only a mild keratitis in 50% of the recipients. Transfer of CD8+ cells from either donor strain did not result in stromal disease in any recipient mouse. These results clearly demonstrate the pivotal role of CD4+ T cells in the development of necrotizing herpes stromal keratitis, and further demonstrate that CD8+ T cells are not essential in HSK development in the BALB/c system.