Utilization of multiplex polymerase chain reaction for simultaneous and rapid detection of viral infections from different ocular structures.

The impact of viral keratitis (VK) on individuals and society is notable. Early diagnosis and treatment are crucial in managing viral keratitis effectively. Timely intervention with antiviral medications and supportive care can help mitigate the severity of the infection and improve visual outcomes. We examined the prevalence of varicella-zoster virus (VZV), herpes simplex virus type 1 (HSV-1), adenovirus (AdV) and herpes simplex virus type 2 (HSV-2) in patients suspected for ocular infections. Patients included in the study exhibited various clinical manifestations indicative of ocular pathology, such as infectious keratitis, corneal scar, endogenous endophthalmitis, panuveitis, endothelitis, stromal edema, and other relevant conditions. Four different types of tear fluid, corneal samples epithelium, aqueous humor and vitreous humor were taken. After genome extraction, multiplex real-time PCR was used for diagnosis of viruses. 48 (29.6%) out of the total of 162 (100%) eye specimen were positive. The dominant prevalence was VZV (12.3%) and HSV-1 (11.7%) followed by AdV (4.9%) and HSV-2 (0.6%). There were 4 (8.3%) coinfections within the samples (HSV-1 and VZV). Aqueous humor samples demonstrated superior virus detection ability and our only HSV-2 positive sample was from aqueous humor. The utilization of multiplex real-time PCR assays in differential diagnosis of VK holds promise for expeditious diagnoses while also preventing unwarranted antibiotic prescriptions. Moreover, the aqueous humor appears to be a more sensitive site for detecting viral keratitis.

Disparities in burden of herpes simplex virus type 2 in China: systematic review, meta-analyses, and meta-regressions.

Background: The rising prevalence of herpes simplex type 2 (HSV-2) infection poses a growing global public health challenge. A comprehensive understanding of its epidemiology and burden disparities in China is crucial for informing targeted and effective intervention strategies in the future. Methods: We followed Cochrane and PRISMA guidelines for a systematic review and included publications published in Chinese and English bibliographic systems until March 31st, 2024. We synthesized HSV-2 seroprevalence data across different population types. We used random-effects models for meta-analyses and conducted meta-regression to assess the association between population characteristics and seroprevalence. Results: Overall, 23,999 articles were identified, and 402 publications (1,203,362 participants) that reported the overall seroprevalence rates (858 stratified measures) were included. Pooled HSV-2 seroprevalence among the general population (lower risk) was 7.7% (95% CI: 6.8-8.7%). Compared to the general population, there is a higher risk of HSV-2 prevalence among intermediate-risk populations (14.8%, 95% CI: 11.0-19.1%), and key populations (31.7%, 95% CI: 27.4-36.1%). Female sexual workers (FSWs) have the highest HSV-2 risk (ARR:1.69, 95% CI: 1.61-1.78). We found northeastern regions had a higher HSV-2 seroprevalence than other regions (17.0%, 95% CI: 4.3-35.6%, ARR: 1.38, 95% CI: 1.26-1.50, Northern China as the reference group). This highlighted the disparity by population risk levels and regions. We also found lower HSV-2 prevalence estimates in publications in Chinese bibliographic databases than those in English databases among key populations (such as MSM and HIV-discordant populations). Conclusion: There is a gradient increase in HSV-2 prevalence risk stratification. We also identified region, population, and age disparities and heterogeneities by publication language in the HSV-2 burden. This study provides guidance for future HSV-2 prevention to eliminate disparities of HSV-2 infection and reduce overall HSV-2 burden. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=408108, identifier CRD42023408108.

Expansion of the HSV-2-specific T cell repertoire in skin after immunotherapeutic HSV-2 vaccine.

The skin at the site of HSV-2 reactivation is enriched for HSV-2-specific T cells. To evaluate whether an immunotherapeutic vaccine could elicit skin-based memory T cells, we studied skin biopsies and HSV-2-reactive CD4+ T cells from PBMCs by T cell receptor (TCR) ß chain (TRB) sequencing before and after vaccination with a replication-incompetent whole-virus HSV-2 vaccine candidate (HSV529). The representation of HSV-2-reactive CD4+ TRB sequences from PBMCs in the skin TRB repertoire increased after the first vaccine dose. We found sustained expansion after vaccination of unique, skin-based T cell clonotypes that were not detected in HSV-2-reactive CD4+ T cells isolated from PBMCs. In one participant, a switch in immunodominance occurred with the emergence of a TCR αß pair after vaccination that was not detected in blood. This TCRαß was shown to be HSV-2 reactive by expression of a synthetic TCR in a Jurkat-based NR4A1 reporter system. The skin in areas of HSV-2 reactivation possessed an oligoclonal TRB repertoire that was distinct from the circulation. Defining the influence of therapeutic vaccination on the HSV-2-specific TRB repertoire requires tissue-based evaluation.

Atypical presentation of herpes simplex virus 2 primary infection: a case report.

BACKGROUND: Cervicitis, an infectious or noninfectious inflammation of the cervix, encompasses a wide range of clinical conditions, from asymptomatic infections to severe lesions, making its diagnosis difficult. Acute cervicitis may develop into pelvic inflammatory disease. In patients with cervicitis, current guidelines recommend testing for herpes simplex virus when external genital lesions are present. Here, we present the case of a patient with an atypical primary herpes simplex virus 2 infection manifesting as cervicitis without genital lesions. CASE PRESENTATION: A 29-year-old Caucasian woman was hospitalized for pelvic inflammatory disease. The patient complained of severe suprapubic pain, fever, and heavy vaginal discharge. The external genitalia were unremarkable, so empirical antibiotic treatment was initiated. Despite 48 hours of well-administered antibiotic therapy, her complaints persisted. Polymerase chain reaction for possible microbial causes was negative for Chlamydia trachomatis and Neisseria gonorrhoeae. There was no bacterial vaginosis. Repeat gynecological examinations with endovaginal ultrasound revealed an enlarged cervix, and pelvic magnetic resonance imaging supported a diagnosis of cervicitis. At this point, additional screening for other sexually transmitted infections and infectious disease-related etiologies of cervicitis was performed, and the polymerase chain reaction analysis of newly isolated samples was positive for herpes simplex virus 2. No antiviral treatment was initiated given the delay in diagnosing herpes simplex virus 2 infection and the slow but spontaneous abatement of symptoms. CONCLUSION: Herpes simplex virus infection should be considered as a possible cause of cervicitis, even in the absence of typical genital lesions. Early detection of herpes simplex virus allows early treatment, helping to reduce the duration and severity of symptoms and therefore potentially reducing recurrences and improving disease control. These data and data from future cases might spur changes in the guidelines on cervicitis testing and treatment.

Twenty years of herpes simplex virus type 2 (HSV-2) research in low-income and middle-income countries: systematic evaluation of progress made in addressing WHO prioritiesfor research in HSV-2 epidemiology and diagnostics.

INTRODUCTION: Low-income and middle-income countries (LMICs) have a high burden of herpes simplex virus type 2 (HSV-2) infection, which has been strongly associated with HIV. In 2001, the WHO hosted a workshop to set research priorities for HSV-2 in LMICs. Periodic re-evaluation of research priorities is essential to ensure effective allocation of resources. This study describes the progress made between 2000 and 2020 in addressing the priorities identified in two of the five thematic areas that were the workshop's focus: HSV-2 epidemiology and diagnostics. The remaining areas are addressed in a companion paper. METHODS: A systematic search of MEDLINE, CINAHL, Global Health and Cochrane databases was carried out. Relevant primary and secondary research studies conducted in LMICs, written in English and published from 2000-2020 were included. Two independent researchers screened, identified papers and extracted preidentified variables from study texts. Data were organised into an Excel spreadsheet and analysed using IBM SPSS V.26. RESULTS: Overall, 4445 discrete papers were identified, of which 165 publications were eligible for inclusion. The highest general population HSV-2 prevalence was reported in South and West Africa. Prevalence was higher among women than men and increased with age. HSV-2 prevalence studies among key populations were few, and the majority were in East and South Asia. Cohort studies of HSV-2 incidence among younger populations (mean age=25 years) and HSV-2 infection prevalence in North Africa and the Middle East were few. The most researched topic in HSV-2 diagnostics addressed serological techniques and direct molecular biology. Studies of point-of-care testing were also few. CONCLUSION: HSV-2 research identified in LMICs has mainly addressed the epidemiology and diagnostics priorities identified by the 2001 WHO workshop. Unaddressed priorities include point-of-care testing, antiviral resistance and exploration of HSV-2 epidemiology in neglected geographical settings and population subgroups.

A review of authorship in herpes simplex virus type-2 (HSV-2) research conducted in low-income and middle-income countries between 2000 and 2020.

INTRODUCTION: Equitable inclusion of low-income and middle-income country (LMIC) researchers and women in research authorship is a priority. A review of progress in addressing WHO-identified priorities provided an opportunity to examine the geographical and gender distribution of authorship in herpes simplex virus type-2 (HSV-2) research. METHODS: Publications addressing five areas prioritised in a WHO workshop and published between 2000 and 2020 were identified. Data on author country, gender, authorship position and research funding source were collected by manuscript review and internet searches and analysed using IBM SPSS V.26. RESULTS: Of, 297 eligible papers identified, (n=294) had multiple authors. Of these, 241 (82%) included at least one LMIC author and 143 (49%) and 122 (41%) had LMIC first and last authors, respectively. LMICs funded studies were more than twice as likely to include an LMIC first or last author as high-income country-funded studies (relative risk 2.36, 95% CI 1.93 to 2.89). Respectively, 129 (46%) and 106 (36%) studies had female first and last authors. LMIC first and last authorship varied widely by HSV-2 research area and increased over time to 65% and 59% by 2015-2020. CONCLUSION: Despite location of the research itself in LMIC settings, over the 20-year period, LMIC researchers held only a minority of first and last authorship positions. While LMIC representation in these positions improved over time, important inequities remain in key research areas and for women. Addressing current and historical power disparities in global health research, research infrastructure and how it is funded may be key addressing to addressing these issues.

20 years of herpes simplex virus type 2 (HSV-2) research in low-income and middle-income countries: systematic evaluation of progress made in addressing WHO priorities for research in HSV-2/HIV interactions, HSV-2 control and mathematical modelling.

INTRODUCTION: Reviewing and updating research priorities is essential to assess progress and to ensure optimal allocation of financial and human resources in research. In 2001, WHO held a research priority setting workshop for herpes simplex virus type 2 (HSV-2) research in low-income and middle-income countries (LMICs). This study aimed to describe progress between 2000 and 2020 in three of the five key research priority areas outlined in the workshop: HSV-2/HIV interactions, HSV-2 control measures and HSV-2 mathematical modelling. The remaining priorities are addressed in a companion paper. METHOD: A systematic literature search of MEDLINE, CINAHL, Global Health and Cochrane databases was carried out. Relevant primary research studies based in LMICs, written in English and published on 2000-2020 were included. Papers were screened by two independent reviewers, and suitable variables were selected for manual extraction from study texts. Data were organised into an Excel spreadsheet and analysed using IBM SPSS. RESULTS: In total, 3214 discrete papers were identified, of which 180 were eligible for inclusion (HSV-2/HIV interactions, 98; control measures, 58; mathematical modelling, 24). Most studies were conducted in East Africa. The majority of the 2001 WHO HSV-2 research priorities were addressed at least in part. Overall, despite several studies describing a strong relationship between HSV-2 and the acquisition and transmission of HIV, HSV-2 control repeatedly demonstrated little effect on HIV shedding or transmission. Further, although mathematical modelling predicted that vaccines could significantly impact HSV-2 indicators, HSV-2 vaccine studies were few. Studies of antiviral resistance were also few. CONCLUSION: Since 2000, LMIC HSV-2 research addressing its control, HIV interactions and mathematical modelling has largely addressed the priorities set in the 2001 WHO HSV-2 workshop. However, key knowledge gaps remain in vaccine research, antiviral cost-effectiveness, antiviral resistance and specific geographical areas.

Local Power: The Role of Tissue-Resident Immunity in Human Genital Herpes Simplex Virus Reactivation.

From established latency, human herpes virus type 2 (HSV-2) frequently reactivates into the genital tract, resulting in symptomatic ulcers or subclinical shedding. Tissue-resident memory (TRM) CD8+ T cells that accumulate and persist in the genital skin at the local site of recrudescence are the "first responders" to viral reactivation, performing immunosurveillance and containment and aborting the ability of the virus to induce clinical lesions. This review describes the unique spatiotemporal characteristics, transcriptional signatures, and noncatalytic effector functions of TRM CD8+ T cells in the tissue context of human HSV-2 infection. We highlight recent insights into the intricate overlaps between intrinsic resistance, innate defense, and adaptive immunity in the tissue microenvironment and discuss how rapid virus-host dynamics at the skin and mucosal level influence clinical outcomes of genital herpes diseases.

Small Animal Models to Study Herpes Simplex Virus Infections.

Herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2) are two of the most prevalent human viruses worldwide. They are known to cause a variety of diseases including genital herpes, meningitis, encephalitis, cold sores and herpes stromal keratitis. The seropositive rate for HSV-1 is around 90%, whereas for HSV-2 it remains around 20-25% for the general adult population. The infections caused by these viruses remain difficult to study because a large proportion of infected individuals are asymptomatic. Furthermore, given the neurotropic characteristics of the virus, studies aimed at understanding the complex pathogenesis in humans is difficult. As a result, animal models have been developed to understand several characteristics of HSV biology, pathogenesis, disease and host responses to infection. These models are also commonly used as the first evaluation of new drugs and vaccines. There are several well-established animal models to study infection with HSV, including mice, guinea pigs and rabbits. Variables within the animal models depend on the species of animal, route of infection, viral strain, dosage, etc. This review aims at summarizing the most commonly used animal models to study HSV pathogenesis and therapies.

The association between alcohol consumption and herpes simplex virus type 2: A cross-sectional study from national health and nutrition examination survey 2009-2016.

BACKGROUND: The current prevalence of Herpes simplex virus type 2 (HSV-2) infection is notably high, with individuals afflicted by HSV-2 facing recurrent outbreaks, challenges in achieving remission, and an elevated risk of HIV infection. This study aims to investigate the relationship between alcohol consumption and HSV-2 infection. METHODS: The data for this study were sourced from 7257 participants who took part in the National Health and Nutrition Examination Survey (NHANES) from 2009 to 2016. The target population consisted of adults with reliable HSV-2 plasma results, and alcohol consumption was assessed using self-report methods. We evaluated the odds ratio (OR) and 95% confidence interval (CI) for the association between alcohol consumption and HSV-2 infection. These estimations were derived from a logistic regression model that was adjusted for key confounding factors. Subgroup analysis specifically focused on alcohol consumption, and the interaction between HSV-2 infection, alcohol consumption, and other variables was assessed through stratified analysis. RESULTS: Among the 7,257 participants included, 89.8% (6,518/7,257) reported varying levels of alcohol consumption history. Compared to individuals who never drinkers, the adjusted odds ratios (ORs) for former drinkers, light drinkers, moderate drinkers, and heavy drinkers were 1.79 (95% CI: 1.34-2.4, p < 0.001), 1.38 (95% CI: 1.07-1.77, p = 0.012), 1.49 (95% CI: 1.15-1.94, p = 0.003), and 1.47 (95% CI: 1.14-1.9, p = 0.003), respectively. The results remained stable in subgroup analyses and sensitivity analyses. CONCLUSION: Current research indicates that individuals with a history of alcohol consumption exhibit a higher risk of HSV-2 infection compared to those who have never drinkers.

Vaccine value profile for herpes simplex virus.

Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) are chronic, highly prevalent viral infections that cause significant morbidity around the world. HSV-2 is sexually transmitted and is the leading cause of genital ulcer disease (GUD). It also increases the risk of HIV acquisition, fueling the HIV epidemic. HSV-1 is typically acquired in childhood through nonsexual contact and contributes to oral and ocular disease, but it can also be sexually transmitted to cause GUD. Both HSV-1 and HSV-2 cause neonatal herpes and neurologic disease. Given the ubiquitous nature of HSV-1 and HSV-2 infections and the limited existing prevention and control measures, vaccination would be the most efficient strategy to reduce the global burden of morbidity related to HSV infection. Vaccine strategies include prophylactic vaccination, which would prevent infection among susceptible persons and would likely be given to adolescents, and therapeutic vaccinations, which would be given to people with symptomatic genital HSV-2 infection. This document discusses the vaccine value profile of both types of vaccines. This 'Vaccine Value Profile' (VVP) for HSV is intended to provide a high-level, holistic assessment of the information and data that are currently available to inform the potential public health, economic and societal value of pipeline vaccines and vaccine-like products. This VVP was developed by subject matter experts from academia, non-profit organizations, government agencies and multi-lateral organizations. All contributors have extensive expertise on various elements of the HSV VVP and collectively aimed to identify current research and knowledge gaps. The VVP was developed using only existing and publicly available information.

The Topical Novel Formulations of Interferon α-2в Effectively Inhibit HSV-1 Keratitis in the Rabbit Eye Model and HSV-2 Genital Herpes in Mice.

Herpes simplex viruses type 1 (HSV-1) and type 2 (HSV-2) are widespread human pathogens that establish chronic latent infections leading to recurrent episodes. Current treatments are limited, necessitating the development of novel antiviral strategies. This study aimed to assess the antiviral efficacy of novel topical formulations containing interferon alpha-2b (IFN α-2b) against HSV-1 and HSV-2. The formulations, Oftalmoferon® forte (eye drops) and Interferon Vaginal Tablets, demonstrated potent antiviral effects against HSV-1 and HSV-2 in Vero cells, respectively, with concentration-dependent inhibition of viral replication. Subsequently, their efficacy was tested in animal models: HSV-1 keratitis in the rabbit eye model and HSV-2 genital herpes in mice. Oftalmoferon® forte effectively treated HSV-1 keratitis, reducing clinical symptoms and ulcerations compared to virus control. Interferon Vaginal Tablets showed promising results in controlling HSV-2 genital herpes in mice, improving survival rates, reducing clinical signs, weight loss and viral replication. The novel IFN α-2b formulations exhibited significant antiviral activity against HSV infections in cell culture and animal models. These findings suggest the potential of these formulations as alternative treatments for HSV infections, particularly in cases resistant to current therapies. Further studies are warranted to optimize treatment regimens and assess clinical efficacy in humans.

A case for implementing an HSV1/2, VZV, and syphilis lesion panel in Manitoba, Canada.

Syphilis, caused by Treponema pallidum subsp. pallidum (TPA), is becoming a significant public health concern, with rising incidence in Manitoba exceeding the national average. The province has also seen a demographic shift leading to women representing 51.9% of cases in 2021, leading to the re-emergence of congenital syphilis. Given the similarities in lesion appearance between TPA and other pathogens such as herpesviruses, accurate diagnosis is crucial for effective management and prevention. In order to address the potential for missed TPA cases, we conducted a quality assurance study from June 2021 to March 2023, screening over 5,000 mucocutaneous lesion swabs for TPA, initially submitted for herpes simplex virus (HSV) and varicella zoster virus (VZV) testing. Positivity rates were 13% for HSV1, 13% for HSV2, 6.7% for VZV, and 6.6% for TPA. Turnaround times (TAT) for TPA testing, as a send-out to the reference laboratory, averaged 17.8 days. Of the TPA-positive specimens, 36% did not have a corresponding TPA PCR test ordered, and 19% did not have accompanying syphilis serology within 30 days of collection. Creation of a multiplex lesion panel identified high sensitivity and specificity for HSV1, HSV2, VZV, and TPA, with robust reproducibility across multiple runs. Incorporation of TPA into a lesion panel improved the TAT to 4 days. Our findings emphasize the need for improved testing strategies to combat the syphilis epidemic and enhance public health outcomes.IMPORTANCESyphilis resurgence has become a significant global public health concern. In particular, the Canadian Prairies have been struggling with high incidence since 2016, exceeding the national Canadian average. We undertook a quality assurance study that highlighted significant gaps in diagnosis of acute syphilis, which led to the development of a highly sensitive and specific multiplex lesion assay for the dual detection of herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2), varicella zoster virus (VZV), and syphilis.

Fluorescent octahydrophenazines as novel inhibitors against herpes simplex viruses.

A new series of racemic fluorescent octahydrophenazines (rac-PZ1-11) have been designed and synthesized via the efficient nucleophilic aromatic substitution (SNAr) of tetrafluorobenzenedinitriles (1a-c) and racemic cyclohexane-1,2-diamines (rac-2a and b). The bioactivities of these racemic rac-PZs (20 µM) against herpes simplex virus type-1 (HSV-1) were evaluated by the relative cell viability of Vero cells infected with HSV-1. It was found that rac-PZ3 shows much higher anti-HSV-1 activity than others, with EC50 = 9.2 ± 1.4 µM. Further investigation into the anti-HSV activities of rac-PZ3 and its enantiomers RR- and SS-PZ3 indicates that rac-PZ3 can also efficiently inhibit HSV-2 and even ACV-resistant HSV-2 (EC50 = 11.0 ± 2.3 and 14.9 ± 2.8 µM, respectively), SS-PZ3 has better activities against HSV-1, HSV-2 and ACV-resistant HSV-2 (EC50 = 4.1 ± 1.1, 5.8 ± 1.0 and 7.9 ± 1.2 µM, respectively), but RR-PZ3 has almost no antiviral activities. The primary mechanism study indicates that rac-PZ3 efficiently reverses the HSV-1/2-induced cytopathic effect and suppresses the expression of viral mRNA and proteins. In addition, rac-, RR- and SS-PZ3 possess excellent fluorescence properties with almost the same emission wavelength and high fluorescence quantum yields (ΦF = 90.3-92.3 % in cyclohexane solutions and 54.4-57.3 % in solids) and can target endoplasmic reticulum and cell membrane. The efficient anti-HSV bioactivities and excellent fluorescence of PZ3 prove its potential applications in antiviral therapy and biological imaging.

External Guide Sequence Effectively Suppresses the Gene Expression and Replication of Herpes Simplex Virus 2.

Ribonuclease P (RNase P) complexed with an external guide sequence (EGS) represents a promising nucleic acid-based gene targeting approach for gene expression knock-down and modulation. The RNase P-EGS strategy is unique as an EGS can be designed to basepair any mRNA sequence and recruit intracellular RNase P for hydrolysis of the target mRNA. In this study, we provide the first direct evidence that the RNase P-based approach effectively blocks the gene expression and replication of herpes simplex virus 2 (HSV-2), the causative agent of genital herpes. We constructed EGSs to target the mRNA encoding HSV-2 single-stranded DNA binding protein ICP8, which is essential for viral DNA genome replication and growth. In HSV-2 infected cells expressing a functional EGS, ICP8 levels were reduced by 85%, and viral growth decreased by 3000 folds. On the contrary, ICP8 expression and viral growth exhibited no substantial differences between cells expressing no EGS and those expressing a disabled EGS with mutations precluding RNase P recognition. The anti-ICP8 EGS is specific in targeting ICP8 because it only affects ICP8 expression but does not affect the expression of the other viral immediate-early and early genes examined. This study shows the effective and specific anti-HSV-2 activity of the RNase P-EGS approach and demonstrates the potential of EGS RNAs for anti-HSV-2 applications.

Development of a highly effective combination monoclonal antibody therapy against Herpes simplex virus.

BACKGROUND: Infections with Herpes simplex virus (HSV)-1 or -2 usually present as mild chronic recurrent disease, however in rare cases can result in life-threatening conditions with a large spectrum of pathology. Monoclonal antibody therapy has great potential especially to treat infections with virus resistant to standard therapies. HDIT101, a humanized IgG targeting HSV-1/2 gB was previously investigated in phase 2 clinical trials. The aim of this study was to develop a next-generation therapy by combining different antiviral monoclonal antibodies. METHODS: A lymph-node derived phage display library (LYNDAL) was screened against recombinant gB from Herpes simplex virus (HSV) -1 and HDIT102 scFv was selected for its binding characteristics using bio-layer interferometry. HDIT102 was further developed as fully human IgG and tested alone or in combination with HDIT101, a clinically tested humanized anti-HSV IgG, in vitro and in vivo. T-cell stimulating activities by antigen-presenting cells treated with IgG-HSV immune complexes were analyzed using primary human cells. To determine the epitopes, the cryo-EM structures of HDIT101 or HDIT102 Fab bound to HSV-1F as well as HSV-2G gB protein were solved at resolutions < 3.5 Å. RESULTS: HDIT102 Fab showed strong binding to HSV-1F gB with Kd of 8.95 × 10-11 M and to HSV-2G gB with Kd of 3.29 × 10-11 M. Neutralization of cell-free virus and inhibition of cell-to-cell spread were comparable between HDIT101 and HDIT102. Both antibodies induced internalization of gB from the cell surface into acidic endosomes by binding distinct epitopes in domain I of gB and compete for binding. CryoEM analyses revealed the ability to form heterogenic immune complexes consisting of two HDIT102 and one HDIT101 Fab bound to one gB trimeric molecule. Both antibodies mediated antibody-dependent phagocytosis by antigen presenting cells which stimulated autologous T-cell activation. In vivo, the combination of HDIT101 and HDIT102 demonstrated synergistic effects on survival and clinical outcome in immunocompetent BALB/cOlaHsd mice. CONCLUSION: This biochemical and immunological study showcases the potential of an effective combination therapy with two monoclonal anti-gB IgGs for the treatment of HSV-1/2 induced disease conditions.

Inhibitory effects of algal polysaccharide extract from Cladophora spp. against herpes simplex virus infection.

Herpes simplex virus (HSV) is a causative agent of fever blister, genital herpes, and neonatal herpes. Nowadays, edible algae are recognized as health food due to high nutrition content and their many active compounds that are beneficial to health. The purpose of this study is to investigate the inhibitory effects of algal polysaccharide extract from Cladophora spp. against herpes simplex virus type 1 and type 2 on Vero cells. In this study, the structure of polysaccharide extract is presented as S=O and C-O-S of the sulfate group, as identified by the FT-IR technique. The toxicity of algal polysaccharide extract on Vero cells was determined by MTT assay. The algal extract showed low toxicity on the cells, with 50% cytotoxic concentration (CC50) value greater than 5000 µg mL-1. The inhibition of HSV infection by the algal extract was then evaluated on Vero cells using plaque reduction assay. The 50% effective concentration (EC50) values of algal extract exhibited antiviral activity against HSV-1 upon treatment before, during, and after viral adsorption with and without removal of the extract were 70.31, 15.17, > 5000 and 9.78 µg mL-1, respectively. Additionally, the EC50 values of algal extract against HSV-2 upon treatment before, during and after viral adsorption with, and without removal of the extract were 5.85, 2.57, > 5000 and 26.96 µg mL-1, respectively. Moreover, the algal extract demonstrated direct inactivation of HSV-1 and HSV-2 virions as well as inhibitory effect against HSV replication. Accordingly, algal polysaccharide extract containing sulfated polysaccharides showed strong activity against HSV. Therefore, it is proved to be useful to apply Cladophora spp. polysaccharide extract as an anti-HSV agent.

VP5 protein of oncolytic herpes simplex virus type 2 induces apoptosis in A549 cells through TP53I3 protein.

Oncolytic virotherapy stands out as a burgeoning and promising therapeutic paradigm, harnessing the intrinsic cytotoxicity of oncolytic viruses for selective replication and dissemination within tumors. The primary mode of action revolves around the direct eradication of tumor cells. In our previous investigations, we formulated an oncolytic herpes simplex virus type 2 (OH2) and substantiated its anti-tumor efficacy both in vivo and in vitro. Subsequently, we embarked on a phase I/II clinical trial in China (NMPA, 2018L02743) and the USA (FDA, IND 27137) to assess OH2's safety, biodistribution, and anti-tumor activity as a standalone agent in patients with advanced solid tumors. In this investigation, our primary focus was to comprehend the influence of the major capsid protein VP5 of OH2 on its efficacy as an antitumor agent. Our findings underscore that the VP5 protein significantly amplifies OH2's oncolytic impact on A549 cells. Additionally, we observed that VP5 actively promotes the induction of apoptosis in A549 cells, both in vivo and in vitro. Through comprehensive transcriptional sequencing, we further authenticated that the VP5 protein triggers apoptosis-related signaling pathways and Gene Ontology (GO) terms in A549 cells. Moreover, we scrutinized differentially expressed genes in the p53-dependent apoptosis pathway and conducted meticulous in vitro validation of these genes. Subsequently, we delved deeper into unraveling the functional significance of the TP53I3 gene and conclusively affirmed that the VP5 protein induces apoptosis in A549 cells through the TP53I3 gene. These revelations illuminate the underlying mechanisms of OH2's antitumor activity and underscore the pivotal role played by the VP5 protein. The outcomes of our study harbor promising implications for the formulation of effective oncolytic virotherapy strategies in cancer treatment.