Herpes Simplex Virus Type 1 Strain Research Articles

Regulation of voltage-gated sodium channels by TNF-α during herpes simplex virus latency establishment.

During lytic or latent infection of sensory neurons with herpes simplex virus type 1 (HSV-1) there are significant changes in the expression of voltage-gated Na+ channels, which may disrupt the transmission of pain information. HSV-1 infection can also evoke the secretion of various pro-inflammatory cytokines, including TNF-α and IL-6. In this work, we hypothesized that TNF-α regulates the expression of Na+ channels during HSV-1 latency establishment in ND7/23 sensory-like neurons. Latency establishment was mimicked by culturing HSV-1 infected ND7/23 cells in the presence of acyclovir (ACV) for 3 days. Changes in the functional expression of voltage-gated Na+ channels were assessed by whole-cell recordings. Our results demonstrate that infection of ND7/23 cells with the HSV-1 strain McKrae with GFP expression (M-GFP) causes a significant decrease in sodium currents during latency establishment. Exposure of ND7/23 cells to TNF-α during latency establishment reverses the effect of HSV-1, resulting in a significant increase in sodium current density. However, Na+ currents were not restored by 3day-treatment with IL-6. There were no changes in the pharmacological and biophysical properties of sodium currents promoted by TNF-α, including sensitivity to tetrodotoxin and the current-voltage relationship. TNF-α stimulation of ND7/23 cells increases p38 signaling. Inhibition of p38 signaling with SB203580 or SB202190 eliminates the stimulatory effect of TNF-α on sodium currents. These results indicate that TNF-α signaling in sensory neurons during latency establishment upregulates the expression of voltage-gated Na+ channels in order to maintain the transmission of pain information.

Identification of a novel neurovirulence factor encoded by the cryptic orphan gene UL31.6 of herpes simplex virus 1.

Although the herpes simplex virus type 1 (HSV-1) genome was thought to contain approximately 80 different protein coding sequences (CDSs), recent multi-omics analyses reported HSV-1 encodes more than 200 potential CDSs. However, few of the newly identified CDSs were confirmed to be expressed at the peptide or protein level in HSV-1-infected cells. Furthermore, the impact of the proteins they encode on HSV-1 infection is largely unknown. This study focused on a newly identified CDS, UL31.6. Re-analyzation of our previous chemical proteomics data verified that UL31.6 was expressed at the peptide level in HSV-1-infected cells. Antisera raised against a viral protein encoded by UL31.6 (pUL31.6) reacted with a protein with an approximate molecular mass of 37 kDa in lysates of Vero cells infected with each of three HSV-1 strains. pUL31.6 was efficiently dissociated from virions in high-salt solution. A UL31.6-null mutation had a minimal effect on HSV-1 gene expression, replication, cell-to-cell spread, and morphogenesis in Vero cells; in contrast, it significantly reduced HSV-1 cell-to-cell spread in three neural cells but not in four non-neural cells including Vero cells. The UL31.6-null mutation also significantly reduced the mortality and viral replication in the brains of mice after intracranial infection, but had minimal effects on pathogenic manifestations in and around the eyes, and viral replication detected in the tear films of mice after ocular infection. These results indicated that pUL31.6 was a tegument protein and specifically acted as a neurovirulence factor by potentially promoting viral transmission between neuronal cells in the central nervous system.IMPORTANCERecent multi-omics analyses reported the herpes simplex virus type 1 (HSV-1) genome encodes an additional number of potential coding sequences (CDSs). However, the expressions of these CDSs at the peptide or protein levels and the biological effects of these CDSs on HSV-1 infection remain largely unknown. This study annotated a cryptic orphan CDS, termed UL31.6, an HSV-1 gene that encodes a tegument protein with an approximate molecular mass of 37 kDa, which specifically acts as a neurovirulence factor. Our study indicates that HSV-1 proteins important for viral pathogenesis remain to be identified and a comprehensive understanding of the pathogenesis of HSV-1 will require not only the identification of cryptic orphan CDSs using emerging technologies but also step-by-step and in-depth analyses of each of the cryptic orphan CDSs.

Comparison of strain specific pathogenicity of Herpes Simplex Virus Type 1 by high-throughput sequencing

Herpes Simplex Virus Type 1 (HSV-1) is a widespread human pathogen known for causing a spectrum of clinical manifestations, ranging from mild cold sores to severe complications like encephalitis. Understanding the strain-specific variations of HSV-1 is crucial for elucidating its pathogenesis and developing targeted therapeutic interventions. In this multifaceted study, we investigated the strain-specific characteristics of HSV-1 using an in vivo rat model. Firstly, a pilot study was conducted to assess the capacity of three HSV-1 strains (Fisher (F), KOS (K), and MacIntyre (M)) to induce cold sores in rats. Remarkably, the F strain exhibited pronounced pathogenicity, inducing erythema, swelling, and disrupted epidermis with ulceration, distinguishing it from the K and M strains. Subsequently, the treatment capability of intravenous acyclovir injection in HSV-1 F strain-infected rats was evaluated. Acyclovir treatment resulted in a significant reduction in HSV-1 viral copy numbers in serum and dissected neuronal tissues, particularly in the spinal cord, brain, and lower lip. Lastly, whole genome sequencing data revealed that high-impact mutations occurred in the K and M strains within the UL49, US2, and US3 genes. These mutations may play a pivotal role in influencing viral replication, dissemination, pathogenesis, and infectivity. In contrast, the moderate missense variant mutations detected in the US12, US8, UL3, UL30, UL31, and UL36 genes appeared to have no effect on viral pathogenesis and infectivity, based on RT-PCR data for spinal cord, trigeminal nerve, brain, and the lower lip. These strain-specific mutations underscore the dynamic nature of HSV-1 evolution. Collectively, our findings contribute to a deeper understanding of HSV-1 strain diversity and pave the way for the development of targeted therapeutic strategies against this medically significant virus.

The antiherpetic and anti-inflammatory activity of the frog-derived peptide Hylin-a1.

The high incidence of virus-related infections and the large diffusion of drug-resistant pathogens stimulate the search and identification of new antiviral agents with a broad spectrum of action. Antivirals can be designed to act on a single target by interfering with a specific step in the viral lifecycle. On the contrary, antiviral peptides (AVPs) are known for acting on a wide range of viruses, with a diversified mechanism of action targeting virus and/or host cell. In the present study, we evaluated the antiviral potential of the peptide Hylin-a1 secreted by the frog Hypsiobas albopunctatus against members of the Herpesviridae family. The inhibitory capacity of the peptide was evaluated in vitro by plaque assays in order to understand the possible mechanism of action. The results were also confirmed by real-time PCR and Western blot evaluating the expression of viral genes. Hylin-a1 acts to block the herpetic infection interfering at the early stages of both herpes simplex virus type 1 (HSV-1) and type 2 infection. Its mechanism is mainly directed on the membrane, probably by damaging the viral envelope. The same effect was also observed against HSV-1 strains resistant to acyclovir. The data presented in this study, such as the increased activity of the peptide when combined to acyclovir, a weak hemolytic profile, an anti-inflammatory effect, and a tolerable half-life in serum, indicates Hylin-a1 as a novel antiherpetic molecule with promising potential in the clinical setting.

CRISPR/Cas9-mediated genome editing of the thymidine kinase gene in a clinical HSV-1 isolate identifies F289S as novel acyclovir-resistant mutation

Herpes simplex virus type 1 (HSV-1) is a neurotropic alphaherpesvirus that establishes a lifelong infection in sensory neurons of infected individuals, accompanied with intermittent reactivation of latent virus causing (a)symptomatic virus shedding. Whereas acyclovir (ACV) is a safe and highly effective antiviral to treat HSV-1 infections, long-term usage can lead to emergence of ACV resistant (ACVR) HSV-1 and subsequently ACV refractory disease. Here, we isolated an HSV-1 strain from a patient with reactivated herpetic eye disease that did not respond to ACV treatment. The isolate carried a novel non-synonymous F289S mutation in the viral UL23 gene encoding the thymidine kinase (TK) protein. Because ACV needs conversion by viral TK and subsequently cellular kinases to inhibit HSV-1 replication, the UL23 gene is commonly mutated in ACVR HSV-1 strains. The potential role of the F289S mutation causing ACVR was investigated using CRISPR/Cas9-mediated HSV-1 genome editing. Reverting the F289S mutation in the original clinical isolate to the wild-type sequence S289F resulted in an ACV-sensitive (ACVS) phenotype, and introduction of the F289S substitution in an ACVS HSV-1 reference strain led to an ACVR phenotype. In summary, we identified a new HSV-1 TK mutation in the eye of a patient with ACV refractory herpetic eye disease, which was identified as the causative ACVR mutation with the aid of CRISPR/Cas9-mediated genome engineering technology. Direct editing of clinical HSV-1 isolates by CRISPR/Cas9 is a powerful strategy to assess whether single residue substitutions are causative to a clinical ACVR phenotype.

Lanatoside C inhibits herpes simplex virus 1 replication by regulating NRF2 distribution within cells

BackgroundIn the past decades, extensive research has been conducted to identify new drug targets for the treatment of Herpes simplex virus type 1 (HSV-1) infections. However, the emergence of drug-resistant HSV-1 strains remains a major challenge. This necessitates the identification of new drugs with novel mechanisms of action. Lanatoside C (LanC), a cardiac glycoside (CG) approved by the US Food and Drug Administration (FDA), has demonstrated anticancer and antiviral properties. Nevertheless, its potential as an agent against HSV-1 infections and the underlying mechanism of action are currently unknown. PurposeThis study aimed to investigate the antiviral activity of LanC against HSV-1 and elucidate its molecular mechanisms. MethodsThe in vitro antiviral activity of LanC was assessed by examining the levels of viral genes, proteins, and virus titers in HSV-1-infected ARPE-19 and Vero cells. Immunofluorescence (IF) analysis was performed to determine the intracellular distribution of NRF2. Additionally, an in vivo mouse model of HSV-1 infection was developed to evaluate the antiviral activity of LanC, using indicators such as intraepidermal nerve fibers (IENFs) loss and viral gene inhibition. ResultsOur findings demonstrate that LanC significantly inhibits HSV-1 replication both in vitro and in vivo. The antiviral effect of LanC is mediated by the perinuclear translocation of NRF2. ConclusionsLanC exhibits anti-HSV-1 effects in viral infections, which are associated with the intracellular translocation of NRF2. These findings suggest that LanC has the potential to serve as a novel NRF2 modulator in the treatment of viral diseases.

Discovery of a Novel Intron in US10/US11/US12 of HSV-1 Strain 17.

Herpes Simplex Virus type 1 (HSV-1) infects humans and causes a variety of clinical manifestations. Many HSV-1 genomes have been sequenced with high-throughput sequencing technologies and the annotation of these genome sequences heavily relies on the known genes in reference strains. Consequently, the accuracy of reference strain annotation is critical for future research and treatment of HSV-1 infection. In this study, we analyzed RNA-Seq data of HSV-1 from NCBI databases and discovered a novel intron in the overlapping coding sequence (CDS) of US10 and US11, and the 3' UTR of US12 in strain 17, a commonly used HSV-1 reference strain. To comprehensively understand the shared US10/US11/US12 intron structure, we used US11 as a representative and surveyed all US11 gene sequences from the NCBI nt/nr database. A total of 193 high-quality US11 sequences were obtained, of which 186 sequences have a domain of uninterrupted tandemly repeated RXP (Arg-X-Pro) in the C-terminus half of the protein. In total, 97 of the 186 sequences encode US11 protein with the same length of the mature US11 in strain 17:26 of them have the same structure of US11 and can be spliced as in strain 17; 71 of them have transcripts that are the same as mature US11 mRNA in strain 17. In total, 76 US11 gene sequences have either canonical or known noncanonical intron border sequences and may be spliced like strain 17 and obtain mature US11 CDS with the same length. If not spliced, they will have extra RXP repeats. A tandemly repeated RXP domain was proposed to be essential for US11 to bind with RNA and other host factors. US10 protein sequences from the same strains have also been studied. The results of this study show that even a frequently used reference organism may have errors in widely used databases. This study provides accurate annotation of the US10, US11, and US12 gene structure, which will build a more solid foundation to study expression regulation of the function of these genes.

Anti-herpes activity of the total alkaloid fraction from the branches of Fusaea longifolia (Annonaceae)

ABSTRACT The herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) occur worldwide. Infections caused by these viruses have great public health importance due to the growing resistance to the first-choice drug, acyclovir, especially in immunosuppressed patients. Alkaloids derived from species of Annonaceae have been reported as antiviral agents against HSV and others viruses. Within this context, we evaluated the antiviral activity of the total alkaloid fraction (TAF) extracted from the branches of Fusaea longifolia (Aubl.) Saff. (Annonaceae), a species native to the Amazon region, against the HSV-1 and HSV-2 viruses. The antiviral activity was evaluated through the plate reduction assay and the mode of action was investigated by a set of other assays. The TAF was active against the HSV-2 strain 333 and against the HSV-1 strains KOS and 29R (acyclovir resistant), with selectivity index values (SI = 50% cytotoxic concentration/50% effective concentration) of 5, 4 and 3, respectively. In the preliminary study of the anti-HSV-2 mode of action, TAF showed viral inhibitory effects if added up to 12 h post-infection, had virucidal activity and did not present viral inhibition in pre-treatment. Our results showed that the TAF exhibited anti-HSV activity. Regarding HSV-2, TAF acted after the viral infection and had virucidal activity. A mass spectrometry analysis revealed the presence of nine alkaloids in the TAF that had previously been reported for Annonaceae, including liriodenine, lysicamine and isoboldine, which have been described as potential anti-HSV-1 agents.

Single therapeutic dose of an antiviral UL29 siRNA swarm diminishes symptoms and viral load of mice infected intranasally with HSV-1.

Herpes simplex virus type 1 (HSV-1) is a human pathogen that causes recurrent infections. Acyclovir-resistant strains exist and can cause severe complications, which are potentially untreatable with current therapies. We have developed siRNA swarms that target a 653 base pair long region of the essential HSV gene UL29. As per our previous results, the anti-UL29 siRNA swarm effectively inhibits the replication of circulating HSV strains and acyclovir-resistant HSV strains in vitro, while displaying a good safety profile. We investigated a single intranasal therapeutic dose of a siRNA swarm in mice, which were first inoculated intranasally with HSV-1 and given treatment 4h later. We utilized a luciferase-expressing HSV-1 strain, which enabled daily follow-up of infection with in vivo imaging. Our results show that a single dose of a UL29-targeted siRNA swarm can inhibit the replication of HSV-1 in orofacial tissue, which was reflected in ex vivo HSV titers and HSV DNA copy numbers as well as by a decrease in a luciferase-derived signal. Furthermore, the treatment had a tendency to protect mice from severe clinical symptoms and delay the onset of the symptoms. These results support the development of antiviral siRNA swarms as a novel treatment for HSV-1 infections.

Novel inhibitors of HSV-1 protease effective in vitro and in vivo

Herpes simplex virus type 1 (HSV-1) is a widespread human pathogen known to cause infections of diverse severity, ranging from mild ulceration of mucosal and dermal tissues to life-threatening viral encephalitis. In most cases, standard treatment with acyclovir is sufficient to manage the disease progression. However, the emergence of ACV-resistant strains drives the need for new therapeutics and molecular targets. HSV-1 VP24 is a protease indispensable for the assembly of mature virions and, as such, constitutes an interesting target for the therapy. In this study, we present novel compounds, KI207M and EWDI/39/55BF, that block the activity of VP24 protease and consequently inhibit HSV-1 infection in vitro and in vivo. The inhibitors were shown to prevent the egress of viral capsids from the cell nucleus and suppress the cell-to-cell spread of the infection. They were also proven effective against ACV-resistant HSV-1 strains. Considering their low toxicity and high antiviral potency, the novel VP24 inhibitors could provide an alternative for treating ACV-resistant infections or a drug to be used in combined, highly effective therapy.

Ethanol extract from Artemisia argyi leaves inhibits HSV-1 infection by destroying the viral envelope

Herpes simplex virus type 1 (HSV-1) is a widely disseminated virus that establishes latency in the brain and causes occasional but fatal herpes simplex encephalitis. Currently, acyclovir (ACV) is the main clinical drug used in the treatment of HSV-1 infection, and the failure of therapy in immunocompromised patients caused by ACV-resistant HSV-1 strains necessitates the requirement to develop novel anti-HSV-1 drugs. Artemisia argyi, a Traditional Chinese Medicine, has been historically used to treat inflammation, bacterial infection, and cancer. In this study, we demonstrated the antiviral effect and mechanism of ethanol extract of A. argyi leaves (hereafter referred to as ‘AEE’). We showed that AEE at 10 μg/ml exhibits potent antiviral effects on both normal and ACV-resistant HSV-1 strains. AEE also inhibited the infection of HSV-2, rotavirus, and influenza virus. Transmission electron microscopy revealed that AEE destroys the membrane integrity of HSV-1 viral particles, resulting in impaired viral attachment and penetration. Furthermore, mass spectrometry assay identified 12 major components of AEE, among which two new flavones, deoxysappanone B 7,3ʹ-dimethyl ether, and 3,7-dihydroxy-3′,4ʹ-dimethoxyflavone, exhibited the highest binding affinity to HSV-1 glycoprotein gB at the surface site critical for gB–gH–gL interaction and gB-mediated membrane fusion, suggesting their involvement in inactivating virions. Therefore, A. argyi is an important source of antiviral drugs, and the AEE may be a potential novel antiviral agent against HSV-1 infection.

HSV-1 0∆NLS vaccine elicits a robust B lymphocyte response and preserves vision without HSV-1 glycoprotein M or thymidine kinase recognition

Effective experimental prophylactic vaccines against viral pathogens such as herpes simplex virus type 1 (HSV-1) have been shown to protect the host through T and/or B lymphocyte-driven responses. Previously, we found a live-attenuated HSV-1 mutant, 0ΔNLS used as a prophylactic vaccine, provided significant protection against subsequent ocular HSV-1 challenge aligned with a robust neutralizing antibody response. Yet, how the virus mutant elicited the humoral immune response relative to parental virus was unknown. Herein, we present the characterization of B cell subsets in vaccinated mice at times after primary vaccination and following boost compared to the parental virus, termed GFP105. We found that 0∆NLS-vaccinated mice possessed more CD4+ follicular helper T (TFH) cells, germinal B cells and class-switched B cells within the first 7 days post-vaccination. Moreover, 0∆NLS vaccination resulted in an increase in plasmablasts and plasma cells expressing amino-acid transporter CD98 along with an elevated titer of HSV-1-specific antibody compared to GFP105-vaccinated animals. Furthermore, O∆NLS-vaccine-induced CD4+ (TFH) cells produced significantly more IL-21 compared to mice immunized with the parental HSV-1 strain. In contrast, there were no differences in the number of regulatory B cells comparing the two groups of immunized mice. In comparing sera recognition of HSV-1-encoded proteins, it was noted antiserum from GFP105-vaccinated mice immunoprecipitated HSV-1 thymidine kinase (TK) and glycoprotein M (gM) whereas sera from 0∆NLS-immunized mice did not even though both groups of vaccinated mice displayed similar neutralizing antibody titers to HSV-1 and were highly resistant to ocular HSV-1 challenge. Collectively, the results suggest (1) the live-attenuated HSV-1 mutant 0∆NLS elicits a robust B cell response that drives select B cell responses greater than the parental HSV-1 and (2) HSV-1 TK and gM are likely expendable components in efficacy of a humoral response to ocular HSV-1 infection.

The In Vitro Replication, Spread, and Oncolytic Potential of Finnish Circulating Strains of Herpes Simplex Virus Type 1.

Herpes simplex virus type 1 (HSV-1) is the only FDA- and EMA- approved oncolytic virus, and accordingly, many potential oncolytic HSVs (oHSV) are in clinical development. The utilized oHSV parental strains are, however, mostly based on laboratory reference strains, which may possess a compromised cytolytic capacity in contrast to circulating strains of HSV-1. Here, we assess the phenotype of thirty-six circulating HSV-1 strains from Finland to uncover their potential as oHSV backbones. First, we determined their capacity for cell-to-cell versus extracellular spread, to find strains with replication profiles favorable for each application. Second, to unfold the differences, we studied the genetic diversity of two relevant viral glycoproteins (gB/UL27, gI/US7). Third, we examined the oncolytic potential of the strains in cells representing glioma, lymphoma, and colorectal adenocarcinoma. Our results suggest that the phenotype of a circulating isolate, including the oncolytic potential, is highly related to the host cell type. Nevertheless, we identified isolates with increased oncolytic potential in comparison with the reference viruses across many or all of the studied cancer cell types. Our research emphasizes the need for careful selection of the backbone virus in early vector design, and it highlights the potential of clinical isolates as backbones in oHSV development.

Complete Genome Sequence of Herpes Simplex Virus 2 Strain G.

Herpes simplex virus type 2 (HSV-2) is a common causative agent of genital tract infections. Moreover, HSV-2 and HIV infection can mutually increase the risk of acquiring another virus infection. Due to the high GC content and highly repetitive regions in HSV-2 genomes, only the genomes of four strains have been completely sequenced (HG52, 333, SD90e, and MS). Strain G is commonly used for HSV-2 research, but only a partial genome sequence has been assembled with Illumina sequencing reads. In the current study, we de novo assembled and annotated the complete genome of strain G using PacBio long sequencing reads, which can span the repetitive regions, analyzed the ‘α’ sequence, which plays key roles in HSV-2 genome circulation, replication, cleavage, and packaging of progeny viral DNA, identified the packaging signals homologous to HSV-1 within the ‘α’ sequence, and determined both termini of the linear genome and cleavage site for the process of concatemeric HSV-2 DNA produced via rolling-circle replication. In addition, using Oxford Nanopore Technology sequencing reads, we visualized four HSV-2 genome isomers at the nucleotide level for the first time. Furthermore, the coding sequences of HSV-2 strain G have been compared with those of HG52, 333, and MS. Moreover, phylogenetic analysis of strain G and other diverse HSV-2 strains has been conducted to determine their evolutionary relationship. The results will aid clinical research and treatment development of HSV-2.

Tofacitinib Treatment in Primary Herpes Simplex Encephalitis Interferes With Antiviral Response.

Tofacitinib, a Janus kinase inhibitor, is a novel immunosuppressive drug for treatment of rheumatoid arthritis. Herpes simplex virus type 1 (HSV-1) may cause encephalitis during primary infection or following reactivation from a latent state. Long-term tofacitinib treatment may increase the risk of this life-threatening condition. The aim of this study was to investigate the effect of tofacitinib on HSV-1 primary infection using a mouse model. Mice pretreated with tofacitinib were intranasally infected with a clinical strain of HSV-1 and monitored for infection severity and antiviral response. Tofacitinib treatment of HSV-1 primary infection resulted in increased viral loads and worsened clinical outcome. Furthermore, tofacitinib promoted M2 anti-inflammatory phenotype of microglia and infiltrating monocytes, as well as inhibited production of inflammatory and antiviral cytokines by macrophages in vitro. Our findings show that treatment with tofacitinib increases severity of herpes simplex encephalitis in mice, by impairing antiviral response induced by monocytes and microglia.

Harringtonine Inhibits Herpes Simplex Virus Type 1 Infection by Reducing Herpes Virus Entry Mediator Expression.

Herpes simplex virus type 1 (HSV-1) infection induces various clinical disorders, such as herpes simplex encephalitis (HSE), herpes simplex keratitis (HSK), and genital herpes. In clinical intervention, acyclovir (ACV) is the major therapeutic drug used to suppress HSV-1; however, ACV-resistant strains have gradually increased. In the present study, harringtonine (HT) significantly inhibited infection of HSV-1 as well as two ACV-resistant strains, including HSV-1 blue and HSV-1 153. Time-of-drug addition assay further revealed that HT mainly reduced the early stage of HSV-1 infection. We also demonstrated that HT mainly affected herpes virus entry mediator (HVEM) expression as shown by qPCR, Western Blot, and Immunofluorescence. Collectively, HT showed antiviral activity against HSV-1 and ACV-resistant strains by targeting HVEM and could be a promising therapeutic candidate for mitigating HSV-1-induced-pathogenesis.

Cluster of Symptomatic Graft-to-Host Transmission of Herpes Simplex Virus Type 1 in an Endothelial Keratoplasty Setting

PurposeDescemet's membrane endothelial keratoplasty (DMEK) is becoming the gold standard to treat corneal endothelial dysfunctions worldwide. Compared with conventional penetrating keratoplasty, infectious complications after DMEK are ill defined. We describe the clinical picture of 2 DMEK recipients, operated on the same day and in the same clinic, who developed atypical herpes simplex virus type 1 (HSV-1) infection in the transplant recipient eye within days post-DMEK. Because recipients received cornea tissue from 2 different donors prepared by the same eye bank, the likelihood of a common HSV-1 source was determined.DesignCase series.ParticipantsTwo DMEK recipients who developed atypical intraocular HSV-1 disease shortly after surgery and surplus cornea specimens of 6 donors.MethodsSurplus cornea donor (pre-DMEK cornea remnants and conditioned cornea storage and transport media) and recipient samples (post-DMEK aqueous humor) were assayed for HSV-1 DNA and infectious virus by real-time polymerase chain reaction (RT-PCR) and cell culture, respectively. Target-enriched whole viral genome sequencing was performed on HSV-1 DNA–positive ocular specimens.Main Outcome MeasuresClinical picture of atypical intraocular HSV-1 infection post-DMEK and presence and homology of HSV-1 genomes between ocular specimens of DMEK donors and recipients.ResultsHerpes simplex virus type 1 DNA was detected in aqueous humor and donor cornea specimens of both DMEK cases, but not in the cornea remnants of 6 randomly selected donors processed by the same eye bank. Infectious HSV-1 was isolated from the cornea remnant and corresponding culture medium of 1 cornea donor. Notably, whole-genome sequencing of virus DNA-positive specimens demonstrated exceptionally high genetic similarity between HSV-1 strains in recipient and donor specimens of both DMEK cases.ConclusionsData indicate cross-contamination of cornea grafts during DMEK preparation with subsequent graft-to-host HSV-1 transmission that caused atypical sight-threatening herpetic eye disease shortly after DMEK. Ophthalmologists should be aware that HSV-1 transmission by DMEK is possible and can lead to atypical ocular disease, a condition that can easily be prevented by taking appropriate technical and clinical measures at both eye bank and surgical levels.

Viral UL8 Is Involved in the Antiviral Activity of Oleanolic Acid Against HSV-1 Infection.

Herpes simplex virus type 1 (HSV-1) is highly prevalent in humans and can cause severe diseases, especially in immunocompromised adults and newborns, such as keratitis and herpes simplex encephalitis. At present, the clinical therapeutic drug against HSV-1 infection is acyclovir (ACV), and its extensive usage has led to the emergence of ACV-resistant strains. Therefore, it is urgent to explore novel therapeutic targets and anti-HSV-1 drugs. This study demonstrated that Oleanolic acid, a pentacyclic triterpenoid widely existing in natural product, had strong antiviral activity against both ACV-sensitive and -resistant HSV-1 strains in different cells. Mechanism studies showed that Oleanolic acid exerted its anti-HSV-1 activity in the immediate early stage of infection, which involved the dysregulation of viral UL8, a component of viral helicase-primase complex critical for viral replication. In addition, Oleanolic acid significantly ameliorated the skin lesions in an HSV-1 infection mediated zosteriform model. Together, our study suggested that Oleanolic acid could be a potential candidate for clinical therapy of HSV-1 infection-related diseases.

Lupeol impairs herpes simplex virus type 1 replication by inhibiting the promoter activity of the viral immediate early gene α0.

Herpes simplex virus type 1 (HSV-1) is an important human pathogenic virus. It is urgent to develop novel antiviral targets because of the limited treatment options and the emergence of drug resistant strains. In this study, we tested the antiviral activity of lupeol, a triterpenoid compound, against HSV-1 and acyclovir (ACV) resistant strains. Lupeol significantly inhibited HSV-1 (F strain) and ACV-resistant strains including HSV-1/106, HSV-1/153, and HSV-1/Blue. Lupeol activity of the HSV-1α0 and α4 promoters, therefore down regulating the expression of the α0, α4, and α27 genes. Collectively, lupeol showed strong antiviral activity against HSV-1 and ACV-resistant strains, and could be a promising therapeutic candidate for HSV-1 pathogenesis. Keywords: herpes simplex virus 1; lupeol; ACV-resistant strains; promoter.

Anterograde Neuronal Circuit Tracers Derived from Herpes Simplex Virus 1: Development, Application, and Perspectives.

Herpes simplex virus type 1 (HSV-1) has great potential to be applied as a viral tool for gene delivery or oncolysis. The broad infection tropism of HSV-1 makes it a suitable tool for targeting many different cell types, and its 150 kb double-stranded DNA genome provides great capacity for exogenous genes. Moreover, the features of neuron infection and neuron-to-neuron spread also offer special value to neuroscience. HSV-1 strain H129, with its predominant anterograde transneuronal transmission, represents one of the most promising anterograde neuronal circuit tracers to map output neuronal pathways. Decades of development have greatly expanded the H129-derived anterograde tracing toolbox, including polysynaptic and monosynaptic tracers with various fluorescent protein labeling. These tracers have been applied to neuroanatomical studies, and have contributed to revealing multiple important neuronal circuits. However, current H129-derived tracers retain intrinsic drawbacks that limit their broad application, such as yet-to-be improved labeling intensity, potential nonspecific retrograde labeling, and high toxicity. The biological complexity of HSV-1 and its insufficiently characterized virological properties have caused difficulties in its improvement and optimization as a viral tool. In this review, we focus on the current H129-derived viral tracers and highlight strategies in which future technological development can advance its use as a tool.