Herpes simplex keratitis:A brief clinical overview

The aim of our minireview is to provide a brief overview of the diagnosis,clinical aspects,treatment options,management,and current literature available regarding herpes simplex keratitis(HSK).This type of corneal viral infection is caused by the herpes simplex virus(HSV),which can affect several tissues,including the cornea.One significant aspect of HSK is its potential to cause recurrent episodes of inflammation and damage to the cornea.After the initial infection,the HSV can establish a latent infection in the trigeminal ganglion,a nerve cluster near the eye.The virus may remain dormant for extended periods.Periodic reactivation of the virus can occur,leading to recurrent episodes of HSK.Factors triggering reactivation include stress,illness,immunosuppression,or trauma.Recurrent episodes can manifest in different clinical patterns,ranging from mild epithelial involvement to more severe stromal or endothelial disease.The severity and frequency of recurrences vary among individuals.Severe cases of HSK,especially those involving the stroma and leading to scarring,can result in vision impairment or even blindness in extreme cases.The cornea's clarity is crucial for good vision,and scarring can compromise this,potentially leading to visual impairment.The management of HSK involves not only treating acute episodes but also implementing long-term strategies to prevent recurrences and attempt repairs of corneal nerve endings via neurotization.Antiviral medications,such as oral Acyclovir or topical Ganciclovir,may be prescribed for prophylaxis.The immune response to the virus can contribute to corneal damage.Inflammation,caused by the body's attempt to control the infection,may inadvertently harm the corneal tissues.Clinicians should be informed about triggers and advised on measures to minimize the risk of reactivation.In summary,the recurrent nature of HSK underscores the importance of both acute and long-term management strategies to preserve corneal health and maintain optimal visual function.

Interleukin 1βreceptor and synaptic dysfunction in recurrent brain infection with Herpes simplex virus type-1

Several experimental evidence suggests a link between brain Herpes simplex virus type-1 infection and the occurrence of Alzheimer’s disease.However,the molecular mechanisms underlying this association are not completely understood.Among the molecular mediators of synaptic and cognitive dysfunction occurring after Herpes simplex virus type-1 infection and reactivation in the brain neuroinflammatory cytokines seem to occupy a central role.Here,we specifically reviewed literature reports dealing with the impact of neuroinflammation on synaptic dysfunction observed after recurrent Herpes simplex virus type-1 reactivation in the brain,highlighting the role of interleukins and,in particular,interleukin 1βas a possible target against Herpes simplex virus type-1-induced neuronal dysfunctions.

Bilateral meibomian gland morphological alterations in unilateral herpes simplex keratitis based on artificial intelligence analysis

AIM:To explore whether unilateral herpes simplex keratitis(HSK)can cause morphological changes of bilateral meibomian glands(MGs)based on artificial intelligence(AI)analytical system.METHODS:In the retrospective study,29 patients with unilateral HSK and 29 participants matched in terms of age and sex were included as control group.Meibographic images of the upper eyelid using Keratograph 5M and assessed ocular surface parameters including tear meniscus height and tear break-up time.MG density and vagueness values were automatically analyzed and calculated using an AI analytical system.We compared the differences between the affected and the contralateral unaffected eyes in HSK patients,and the normal control eyes.We employed either the paired t-test or the Wilcoxon signed-rank test to compare significant difference between the affected and unaffected eyes in HSK patients or between the HSK group and control group.RESULTS:The MG density was 0.19±0.09 in the HSKaffected eye and 0.18±0.07 in contralateral unaffected eye,which had no significant difference(P=0.616).The MG density between the affected eye with HSK and the normal control group was statistically significant(P=0.028).There was a significant difference in MG density between the contralateral unaffected eye and the normal control group(P=0.012).However,no significant difference in vagueness value was observed between the eye with HSK and the control group or between HSK eye and contralateral eye.CONCLUSION:The MG density between the HSKaffected eye and the contralateral unaffected eye don’t significantly differ,whereas there is a significant decrease in the HSK group compared to that of the normal participants.Unilateral HSV keratitis may suffer from bilateral changes of MG morphology indicating bilateral dry eye.Therefore,the fellow eye of patients with unilateral HSK should be considered a potential case of MG dysfunction,necessitating early treatment for bilateral dry eye in the clinic.

Black Garlic as an Antiviral for Herpes Simplex Virus-2 in Lung Cells

Allicin, an antioxidant, is known for providing garlic with its unique fragrance and taste, as well as for its antimicrobial properties. Black garlic, a fermented form of garlic, contains higher levels of antioxidants than fresh garlic. Antioxidants play a vital role in alleviating cellular stress during viral infections. Viral infections result in oxidative stress through the production of reactive oxidative species (ROS). A prolonged state of oxidative stress can result in cell death, DNA damage, and disease progression. In this study, black garlic extract (BGE) is evaluated for its ability to mitigate cytopathic effects and oxidative stress caused by herpes simplex virus-2 (HSV-2) infections in vitro. Antiviral assays were performed to determine the percent of viral inhibition resulting from treatment with the BGE. ROS-GloTM H2O2 assays were then completed to measure the post-infection ROS levels of BGE-treated virus and cells. The results thus far suggest that BGE may inhibit viral infection and decrease levels of oxidative stress.

Autoimmune complications and clinical outcomes of herpes simplex encephalitis in children: A case series

Objective:To report the neurologic prognosis and autoimmune complications of 16 cases of childhood herpes simplex virus encephalitis.Methods:The study was conducted atŞanlıurfa Training and Research Hospital,Turkey from June 2017 to August 2019.The study included 16 pediatric patients aged between 6 months and 17 years(median age 77.7 months)who were diagnosed with herpes simplex virus type 1 encephalitis by pediatric infectious disease and pediatric neurology clinics.Patients were followed using patient records,and interviews at the pediatric neurology clinic or via the telephone.Clinical and demographic data,received therapies,neurologic prognosis and complications were evaluated.Results:Patients with and without autoimmune encephalitis were compared in terms of age,sex,symptom duration before treatment,initial cerebrospinal fluid protein,glucose,red blood count and white blood count but no significant difference was found.Autoimmune complications were seen in four patients.N-methyl-D-aspartate encephalitis was observed in three patients and choreoathetosis was seen in one patient.The average follow-up period was 48.3 months.Twenty-five percent of the patients were receiving multiple antiepileptic drug(AED)treatment,43.8%were receiving single AED treatment and 31.3%were not receiving AED treatment at the end of the follow-up.Motor disability was observed in 12.5%and drug-resistant epilepsy was observed in 6.3%who had autoimmune complications.Conclusions:Seizures and movement disorders were controlled with immunotherapy and autoantibodies should be studied routinely.Treatment should be started early upon recognition of autoimmune complications through follow-up by measuring autoantibody levels and clinical examination results.Effective prevention and curative treatment modalities are needed to avoid herpes simplex virus encephalitis complications.

Antiviral activity of mangiferin from the rhizome of Anemarrhena asphodeloides against herpes simplex virus type 1

Objective:To evaluate the antiviral activity of pure compounds against herpes simplex virus type 1(HSV-1)from the rhizome of Anemarrhena asphodeloides.Methods:Bioassay-guided isolation was conducted to separate the active compound and its chemical structure was elucidated by spectral analysis.In vitro antiviral efficacy of active compound was detected by Cell Counting Kit-8 assay,plaque reduction assay,and fluorescence observation.RT-PCR was used to determine the viral load and the cytokine-related gene expression after HSV-1 infection.In vivo study was also conducted to further determine antiviral efficacy of an active compound against HSV-1.Results:An active compound was isolated and elucidated as mangiferin.Mangiferin significantly inhibited the replication of HSV-1 in Vero cells with a half maximal inhibitory concentration(IC_(50))of 64.0 mg/L.Time-of-addition and time-of-removal assays demonstrated that mangiferin could effectively inhibit the replication of HSV-1 in the early stage(8 h).UL12,UL42,and UL54 gene expression levels of HSV-1 in the 64 mg/L mangiferin-treated group were markedly reduced as compared with the HSV-1 group(P<0.01).Fluorescence observation showed that mangiferin attenuated the mitochondrial damage maintainingΔΨm induced by HSV-1 in Vero cells.The expression of inflammatory factors TNF-α,IL-1β,and IL-6 was remarkably increased in the virus-infected group as compared with that in the normal group(P<0.05),the levels of these inflammatory factors dropped after treatment with mangiferin.Mangiferin significantly decreased the viral load and attenuated the HSV-1-induced up-regulation of TNF-α,IL-1β,and IL-6.The relative protection rate of HSV-1-infected mice could reach up to55.5%when the concentration of mangiferin was 4 g/kg.Conclusions:Mangiferin exhibits promising antiviral activity against HSV-1 in vitro and in vivo and could be a potential antiviral agent for HSV-1.

Streptococcus pneumoniae and Herpes Simplex Virus-1 Central Nervous System Co-Infection

Co-infections of the central nervous system (CNS) caused by bacterial and viral pathogens are considered to be rare. Herpes simplex virus type-1 (HSV-1) reactivation following Streptococcus pneumoniae infection is well described but most cases are related to oral or cutaneous lesions or in respiratory samples. HSV-1 CNS reactivation after Streptococcus pneumoniae meningitis is a very rare event and may have significant morbidity and mortality. In this case report, we describe a 71-year-old female patient that presented with a history of abdominal pain and confusion/disorientation that had tonic-clonic seizures while in the Emergency Department. The diagnostic work-up confirmed CNS co-infection caused by Streptococcus pneumoniae and HSV-1. Of note, beyond age, the patient had no known risk factors for both entities and recovered fully after antibiotic and antiviral therapy. This case underlines that clinicians must be aware of CNS co-infection despite being a rare diagnosis. This should be suspected particularly in patients who present an unusual clinical course of CNS infection.

A Meta-Analysis on the Correlation Between Herpes Simplex Virus Type II Infection and Adverse Pregnancy Outcomes in China

Objective:To systematically evaluate the relationship between herpes simplex virus type II(HSV-2)infection in pregnant women and the adverse pregnancy outcomes(preterm delivery,spontaneous abortion,stillbirth,monstrum,low birth weight,intrauterine growth retardation,premature rupture of membranes),so as to provide clinical guidance for the prevention and treatment of adverse pregnancy outcomes caused by HSV-2 infection in pregnant women.Methods:2140 articles were collected from PubMed,China National Knowledge Infrastructure(CNKI),and other databases for the past 20 years.According to the inclusion criteria,the literatures about the relationship between HSV-2 infection of pregnant women and adverse pregnancy outcomes were screened.The effect model was determined by heterogeneity test results,and the meta-analysis was carried out by RevMan 5.3 software.Results:The results of meta-analysis showed that the positive rate of HSV-2 was higher in the adverse pregnancy group than in the control group(odds ratio[OR]:7.92,95%confidence interval[Cl]:3.91-16.01),and the difference was statistically significant.Conclusion:HSV-2 infection will increase the risk of adverse pregnancy outcomes.Prevention and effective control of HSV-2 infection in early pregnancy can reduce the rate of adverse pregnancy outcome,which is of great significance to the promotion of eugenics.

Oral and perioral herpes simplex virus infection type I in a fivemonth- old infant: A case report

BACKGROUND Herpes simplex virus(HSV)is a highly infectious pathogen that is easily transmitted via the bodily fluids of an infected individual.This virus usually affects individuals older than six months of age,and rarely causes lesions or symptoms in younger patients.CASE SUMMARY We present the case of a five-month-old healthy girl who presented with painful herpetic gingivostomatitis and perioral vesicles.We discuss the pathophysiology of primary HSV infection and the effect of maternal antibodies on the infant’s immune system.In addition,we explain the diagnosis,management,and prognosis of HSV infection in young infants.CONCLUSION This case highlights the importance of early diagnosis and management of HSV infections to decrease the risk of developing severe complications and death.

Oncolytic Engineering of ICP34.5 and LAT of Herpes Simplex Virus Type 1

Oncolytic virus (OV) is a kind of virus that can preferentially infect and kill tumor cells. The second oncolytic virus drug was oncolytic herpes simplex virus (oHSV) Talimogene Laherparepvec (T-VEC). HSV-1 infectious cell culture protein 34.5 (ICP34.5) and latency-associated transcript (LAT) genes are closely related to virus selective infection and latent infection. Their engineering is essential for constructing efficient and safe oHSV. We summarized the mechanisms of ICP34.5 and LAT in the course of HSV-1 infection and reviewed the engineered oHSVs. We are aimed to provide an insight in developing oHSV in the future.

New strategies against drug resistance to herpes simplex virus

Herpes simplex virus （HSV）, a member of the Herpesviridae family, is a significant human pathogen that results in mucocutaneous lesions in the oral cavity or genital infections. Acyclovir （ACV） and related nucleoside analogues can successfully treat HSV infections, but the emergence of drug resistance to ACV has created a barrier for the treatment of HSV infections, especially in immunocompromised patients. There is an urgent need to explore new and effective tactics to circumvent drug resistance to HSV. This review summarises the current strategies in the development of new targets （the DNA helicase/primase （H/P） complex）, new types of molecules （nature products） and new antiviral mechanisms （lethal mutagenesis of Janus-type nucleosides） to fight the drug resistance of HSV.

The Herpes Simplex Virus Type 1 Multiple Function Protein ICP27

The herpes simplex virus type 1 （HSV-1） infected-cell protein 27 （ICP27） is an essential, highly conserved protein involved in various steps of HSV-1 gene regulation as well as in the shut-off of host gene expression during infection. It functions primarily at the post-transcriptional level in inhibiting precursor mRNA splicing and in promoting nuclear export of viral transcripts. Recently, many novel functions performed by the HSV- 1 ICP27 protein were shown, including leptomycin B resistance, inhibition of the type I interferon signaling, regulation of the viral mRNA translation and determining the composition of HSV-1 virions

Herpes simplex virus-1 infection or Simian virus 40-mediated immortalization of corneal cells causes permanent translocation of NLRP3 to the nuclei

AIM: To investigate into the potential involvement of pyrin containing 3 gene(NLRP3), a member of the nucleotide-binding oligomerization domain-like receptors with cytosolic pattern recognition, in the host defense of corneas against viruses.METHODS: The herpes viral keratitis model was utilized in BALB/c mice with inoculation of herpes simplex virus-1(HSV-1). Corneal tissues removed during therapy of patients with viral keratitis as well as a Simian vacuolating virus 40(SV40)-immortalized human corneal epithelial cell line were also examined.Immunohistochemistry was used to detect NLRP3 in these subjects, focusing on their distribution in tissue or cells. Western blot was used to measure the level of NLRP3 and another two related molecules in NLPR3 inflammasome, namely caspase-1 and IL-1β.RESULTS: The NLRP3 activation induced by HSV-1infection in corneas was accompanied with redistribution of NLRP3 from the cytoplasm to the nucleus in both murine and human corneal epithelial cells. Furthermore,in the SV40-immortalized human corneal epithelial cells,NLRP3 was exclusively located in the nucleus, and treatment of the cells with high concentration of extracellular potassium(known as an inhibitor of NLRP3activation) effectively drove NLRP3 back to the cytoplasm as reflected by both immunohistochemistry and Western blot.· CONCLUSION: It is proposed that herpes virus infection activates and causes redistribution of NLRP3 to nuclei. Whether this NLRP3 translocation occurs with other viral infections and in other cell types merit further study.

Asymptomatic seminal infection of herpes simplex virus:impact on male infertility

In more than half of infertile men, the cause of their infertility is unknown. Several studies revealed the role of viral infections in male infertility. The aim of the present study was to determine the prevalence of herpes simplex virus-1 （HSV-1） and HSV-2 in semen from asymptomatic infertile male patients, and its association with altered semen parameters. A total of 70 semen samples were collected from infertile men who attended the Research and Clinical Center for Infertility in Yazd, Iran. Semen analysis and diagnostic real-time PCR using specific primers and probes for HSV-1 and HSV-2 DNA were performed. Comparison of semen parameters between virally in- fected and non-infected samples were performed with independent t-test and Mann-Whitney test. Semen analysis showed that infertile men fell into two groups, the male factor group and the unexplained group. HSV-1 and HSV-2 DNA was detected in 16 （22.9%） and 10 （14.3%） of 70 semen samples, respectively. All HSV-positive samples had abnormal semen parameters （the male factor group）. Although HSV infection was not associated with sperm motility and morphological defects, it was correlated with lower sperm count in the seminal fluid. The findings suggest that asymptomatic seminal infection of HSV plays an important role in male infertility by adversely af- fecting sperm count.

The miRNAs of Herpes Simplex Virus(HSV)

Herpes simplex virus (HSV) is a group of common human pathogens with two serotypes HSV-1 and HSV-2.The prevalence of HSV is worldwide.It primarily infects humans through epithelial cells,when it introduces a latent infection into the nervous system.During viral latency,only a region known as the latency-associated transcript (LAT) is expressed.The discovery of HSV miRNAs helps to draw a larger picture of the infection and pathogenesis of the virus.This review summarizes miRNAs found in HSV-1 and HSV-2 so far.The functional studies of miRNAs in HSV to date indicate that they play a stage-specific role coordinated with viral proteins to maintain the virus life cycle.

Feasibility of herpes simplex virus type 1 mutants labeled with radionuclides for tumor treatment

For over one hundred years, viruses have been recognized as capable of killing tumor cells. At present, people are still researching and constructing more suitable oncolytic viruses for treating different malignant tumors. Although extensive studies have demonstrated that herpes simplex virus type 1 (HSV-1) is the most potential oncolytic virus, therapies based on herpes simplex virus type 1 vectors still arouse bio-safety and risk management issues. Researchers have therefore introduced the new idea of treating cancer with HSV-1 mutants labeled with radionuclides, combining radionuclide and oncolytic virus therapies. This overview briefly summarizes the status and mechanisms by which oncolytic viruses kill tumor cells, discusses the application of HSV-1 and HSV-1 derived vectors for tumor therapy, and demonstrates the feasibility and prospect of HSV-1 mutants labeled with radionuclides for treating tumors.

Contributions of neurotropic human herpesviruses herpes simplex virus 1 and human herpesvirus 6 to neurodegenerative disease pathology

Human herpesviruses （HVs） have developed ingenious mechanisms that enable them to traverse the defenses of the central nervous system （CNS）. The ability of HVs to enter a state of latency, a defining char- acteristic of this viral family, allows them to persist in the human host indefinitely. As such, HVs represent the most frequently detected pathogens in the brain. Under constant immune pressure, these infections are largely asymptomatic in healthy hosts. However, many neurotropic HVs have been directly connected with CNS pathology in the context of other stressors and genetic risk factors. In this review, we discuss the potential mechanisms by which neurotropic HVs contribute to neurodegenerative disease （NDD） patholo- gy by highlighting two prominent members of the HV family, herpes simplex virus 1 （HSV-1） and human herpesvirus 6 （HHV-6）. We （i） introduce the infectious pathways and replicative cycles of HSV-1 and HHV-6 and then （ii） review the clinical evidence supporting associations between these viruses and the NDDs Alzheimer＇s disease （AD） and multiple sclerosis （MS）, respectively. We then （iii） highlight and dis- cuss potential mechanisms by which these viruses exert negative effects on neurons and glia. Finally, we （iv） discuss how these viruses could interact with other disease-modifying factors to contribute to the initiation and/or progression of NDDs.

A rare cause of dysphagia:Herpes simplex esophagitis

Herpes simplex esophagitis （HSE） is well documented in immunosuppressed patients. However, it is rare in the immunocompetent host. We present a case of HSE in a 21 year-old healthy lady who was admitted to our unit with dysphagia, odynophagia and chest pain. Clinical examination revealed mild epigastric tenderness and admission bloods including full blood picture, electrolytes and inflammatory markers were normal. She underwent an esophagogastroduodenoscopy （EGD） which revealed severe exudative, well-circumscribed ulcerations in her distal esophagus. Biopsies confirmed severe esophagitis with acute ulceration and subsequent polymerase chain reaction （PCR） confirmed herpes simplex virus （HSV） type 1. Subsequent assessment failed to identify an immune disorder. HSE should be suspected when faced with characteristic endoscopic findings, even if the patient is immunocompetent. When the diagnosis of HSE is confirmed, an immune deficiency should be sought.

A functional type I interferon pathway drives resistance to cornea herpes simplex virus type 1 infection by recruitment of leukocytes

Type I interferons are critical antiviral cytokines produced following herpes simplex virus type-1 （HSV-1） infection that act to inhibit viral spread. In the present study, we identify HSV-infected and adjacent uninfected corneal epithelial cells as the source of interferon-a. We also report mice deficient in the A1 chain of the type I IFN receptor （CDl18-/） are extremely sensitive to ocular infection with low doses （100 PFU） of HSV-1 as seen by significantly elevated viral titers in the cornea Compared to wild type （WT） controls. The enhanced susceptibil- ity correlated with a loss of CD4＋ and CD8＋ T cell recruitment and aberrant chemokine production in the cornea despite mounting an adaptive immune response in the draining mandibular lymph node of CDll8/ mice. Taken together, these results highlight the importance of IFN production in both the innate immune response as well as eliciting chemokine production required to facilitate adaptive immune cell trafficking.

The Herpes Simplex Virus Type 1 Infected Cell Protein 22

As one of the immediate-early(IE)proteins of herpes simplex virus type 1(HSV-1),ICP22 is a multifunctional viral regulator that localizes in the nucleus of infected cells.It is required in experimental animal systems and some nonhuman cell lines,but not in Vero or HEp-2 cells.ICP22 is extensively phosphorylated by viral and cellular kinases and nucleotidylylated by casein kinase Ⅱ.It has been shown to be required for efficient expression of early(E)genes and a subset of late(L)genes.ICP22,in conjunction with the UL13 kinase,mediates the phosphorylation of RNA polymerase Ⅱ.Both ICP22 and UL13 are required for the activation of cdc2,the degradation of cyclins A and B and the acquisition of a new cdc2 partner,the UL42 DNA polymerase processivity factor.The cdc2-UL42 complex mediates postranscriptional modification of topoisomerase Ⅱα in an ICP22-dependent manner to promote L gene expression.In addition,ICP22 interacts with cdk9 in a Us3 kinase dependent fashion to phosphorylate RNA polymerase Ⅱ.