Pathogenesis and virulence of herpes simplex virus

Overview on the management of herpes simplex virus infections: Current therapies and future directions

INTRODUCTION

Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) are highly prevalent, infecting approximately 64 % and 13 % of the world's population, respectively. Traditionally, HSV-1 has been associated with orofacial infections and HSV-2 with anogenital infections, but HSV-1 is increasingly the cause of genital infections. The clinical spectrum of HSV disease ranges from mild cold sores to severe conditions such as encephalitis or systemic infection, particularly in immunocompromised individuals and neonates.

AREAS COVERED

Here we summarize the natural history, epidemiology, manifestations, and treatment options for HSV infections. Current treatments, such as acyclovir, target viral DNA polymerase but have limited efficacy and are susceptible to resistance, especially in immunosuppressed populations. Rescue therapies such as foscarnet exhibit limiting toxicity. Vaccine development has been challenging, and a cure for HSV infection remains distant. Gene therapy is still in its early stages, while novel drugs such as helicase primase inhibitors (HPIs) are emerging as a promising alternative, showing high efficacy and the potential to overcome resistance.

EXPERT OPINION

HPIs represent a significant advance in HSV management. Their safety profile and novel mode of action may provide better viral suppression with a lower risk of resistance, offering hope for better control of the disease.

Unveiling the Involvement of Herpes Simplex Virus-1 in Alzheimer's Disease: Possible Mechanisms and Therapeutic Implications

Viruses pose a significant challenge and threat to human health, as demonstrated by the current COVID-19 pandemic. Neurodegeneration, particularly in the case of Alzheimer's disease (AD), is significantly influenced by viral infections. AD is a neurodegenerative disease that affects people of all ages and poses a significant threat to millions of individuals worldwide. The precise mechanism behind its development is not yet fully understood; however, the emergence and advancement of AD can be hastened by various environmental factors, such as bacterial and viral infections. There has been a longstanding suspicion that the herpes simplex virus-1 (HSV-1) may have a role to play in the development or advancement of AD. Reactivation of HSV-1 could potentially lead to damage to neurons, either by direct means or indirectly by triggering inflammation. This article provides an overview of the connection between HSV-1 infections and immune cells (astrocytes, microglia, and oligodendrocytes) in the progression of AD. It summarizes recent scientific research on how HSV-1 affects neurons, which could potentially shed light on the clinical features and treatment options for AD. In addition, the paper has explored the impact of HSV-1 on neurons and its role in various aspects of AD, such as Aβ secretion, tau hyperphosphorylation, metabolic dysregulation, oxidative damage, apoptosis, and autophagy. It is believed that the immune response triggered by HSV-1 reactivation plays a role in the development of neurodegeneration in AD. Despite the lack of a cure for AD, researchers have made significant efforts to study the clinical and pathological aspects of the disease, identify biomarkers, and gain insight into its underlying causes. The goal is to achieve early diagnosis and develop treatments that can modify the progression of the disease. The current article discusses the most promising therapy for combating the viral impacts, which provides additional evidence for the frequent reactivations of latent HSV-1 in the AD brain. However, further research is still required to establish the molecular and cellular mechanisms underlying the development of AD through the reactivation of HSV-1. This could potentially lead to new insights in drug development aimed at preventing HSV-1 reactivation and the subsequent development and progression of AD.

Novel Perspectives Focused on the Relationship Between Herpesvirus Encephalitis and Anti-GFAP-Antibody-Positive Astrocytopathy

Virus encephalitis (VE), recognized as one of the common kinds of central nervous system (CNS) diseases after virus infection, has a surprising correlation with autoimmune encephalitis (AE) when autoimmune antibodies emerge in cerebrospinal fluid (CSF) or serum. Herpes simplex virus and Epstein-Barr virus are the most critical agents worldwide. By molecular mimicry, herpes viruses can invade the brain directly or indirectly. As a type-III intermediate filament, glial fibrillary acidic protein (GFAP) can be seen in both the central and peripheral nervous system and is regarded as a marker of astrocyte activation. Autoimmune glial fibrillary acidic protein astrocytopathy (GFAP-A), an autoimmune inflammatory CNS disorder with unearthed pathogenic mechanism yet, is correlated with CD8 + T cells and AQP4 astrocytopathy in TNF signaling. It brings a new concept of VE and GFAP coexisting, which has been documented in several case reports. Considering the infectious role of herpes viruses in CNS, EBV contributes to GFAP-IgG significantly and may result in GFAP-A. Coincidently, the existence of GFAP-IgG in patients with infection of herpes viruses has been documented as well. There exist multiple diagnoses of VE, ranging from traditional diagnostic criteria, such as CSF examination and electronic techniques, to a novel approach, according to case reports, the detection of GFAP-lgG. In terms of treatment, except for (IVIG), the explorations for new curative targets and optimal diagnostic time are of great necessity. In conclusion, emphasis given to the CNS autoimmune effect brought by the virus infection is highly worthy.

A novel approach utilizing spirocyclic thiopyrimidinone compounds against herpes simplex virus with underlying antiviral mechanisms of action

In recent decades, viral outbreaks have significantly threatened global health, with herpes simplex virus type 2 (HSV-2) being one of the most prevalent infections. This study evaluated novel spiropyrimidine derivatives as potential antiviral agents against HSV-2, building on previous research that examined spirocyclic thiopyrimidinone derivatives against human coronavirus 229E (hCoV-229E). Among the eleven synthesized compounds, spiropyrimidinone derivative 3 demonstrated promising antiviral activity, with a selectivity index of 11.2. The drug mechanism of infection studies indicated that compound 3 primarily inhibits HSV-2 at the viral adsorption stage, achieving approximately 83% inhibition and reducing viral multiplication by 34%. Its efficacy is linked to its diketone moiety, which is known for its ability to enhance antiviral effects. Furthermore, the effect of compound 3 on viral inhibition is reflected in the level of caspase-3 protein expression, revealing that the apoptotic pathway is modulated. Docking studies revealed multiple interactions with herpes virus entry mediator (HVEM), indicating its potential as an entry inhibitor. These findings confirm that compound 3 could be a potential candidate for further development in HSV-2 antiviral therapy.

The producer cell type of HSV-1 alters the proteomic contents and infectious capacity of virions

The cell that a virus replicates in i.e., the producer cell, can alter the macromolecular composition and infectious capacity of the virions that are produced. Herpes Simplex virus type 1 (HSV-1) primarily infects keratinocytes of the epidermis or oral mucosa prior to establishing latency in neurons of the peripheral nervous system, where the virus can persist for the lifetime of the host. Many cell lines that are used to amplify HSV-1 are derived from species and tissue types that are less physiologically relevant to HSV-1 disease. To understand if the producer cell type influences HSV-1 infection, we tested the infectivity of HSV-1 derived from immortalized African green monkey kidney cells (vero), immortalized human keratinocytes (HaCaT), and primary human foreskin fibroblasts (HFF-1). We observed that the producer cell type alters the capacity of HSV-1 to produce viral proteins and infectious virions from infected cells and susceptibility to inhibition of replication by interferon treatment. HaCaT-derived HSV-1 consistently exhibited enhanced replication over HFF-1 or vero-derived virus. To determine if the producer cell type changes the protein composition of virions, we performed an untargeted LC/MS-MS analysis of virions purified from each cell line. Comparison of virion associated proteins revealed quantitative differences in composition of both cellular and viral proteins including ICP0, pUL24 and pUL42. These results highlight the influence that the producer cell-type has on HSV-1 infection outcomes and suggest that cell type specific factors can alter HSV-1 and impact viral replication.

Importance

Approximately 67% of the human population harbors HSV-1 infection. To study HSV-1 infection, laboratories utilize several different cell lines to propagate HSV-1 for downstream experiments. The type of cell used to produce a virus, i.e. the producer cell type, can alter the macromolecular composition, immunogenicity, and infectivity of the virions that are produced across several virus families. We found that the producer cell type of HSV-1 alters virion infectivity and virion protein composition. Therefore, the producer cell type may have implications in the spread of HSV-1 and subsequent disease outcomes in humans. Our results also raise concerns about how the use of different ceil types to propagate HSV-1 may alter the outcome, interpretation, and reproducibility of experimental results.

A Novel pH-Responsive Baicalein@Chitosan Hydrogel for the Topical Treatment of Herpes Simplex Virus Type 1 Skin Infections: Therapeutic Potential and Mechanisms

Herpes simplex virus type 1 (HSV-1) is a prevalent human pathogen primarily transmitted through skin-to-skin contact. Traditional antiviral drugs like acyclovir (ACV) have limitations due to viral resistance and side effects, necessitating the development of alternative therapeutic strategies. Drug-loaded hydrogels have emerged as a promising approach for managing various skin infections. Considering the low-pH microenvironment following HSV-1 infection, a pH-responsive baicalein@chitosan (B@C) hydrogel is developed for the topical treatment of HSV-1 skin infections. This hydrogel is synthesized by incorporating baicalein, a natural flavonoid, into a chitosan matrix modified with 4-formylphenylboronic acid and protocatechualdehyde to achieve potent anti-HSV-1 activity and pH-responsiveness. In vitro results demonstrated the hydrogel's pH-dependent inhibitory effect on HSV-1 infections, including ACV-resistant strains. Subsequent investigations confirmed its efficacy in multiple murine infection models. Mechanistically, the B@C hydrogel inhibited viral replication by modulating the phosphorylation of inhibitor of nuclear factor kappa-B kinase subunit beta, promoted collagen synthesis, and decreased reactive oxygen species generation. Ultra-high-performance liquid chromatography-tandem mass spectrometry analysis revealed a sustained release of baicalein from the hydrogel, ensuring long-term drug retention in HSV-1-infected skin tissues. Collectively, these findings suggest that the B@C hydrogel holds significant potential for the therapeutic management of HSV-1 skin infections.

[Pathophysiology and treatment of acyclovir-resistant herpes simplex virus keratitis]

Herpetic keratitis (HK) caused by herpes simplex virus 1 (HSV-1) is the major cause of infection-related blindness in developed countries. Current treatment is based on curative and preventive use of antiherpetic acyclic nucleoside analogues (ANAs), namely acyclovir (ACV) or other molecules with the same mechanism of action. The frequency of HK caused by acyclovir-resistant viruses is steadily increasing. Virological proof of resistance is obtained from an ocular sample sent to a specialized laboratory. Genotypic characterization by DNA sequencing of the viral enzymes targeted by antivirals allows adaptation of treatment according to the mutation identified. Mutations of the viral thymidine kinase (TK) are the most frequent and leave few viable alternatives for long-term prophylactic treatment among currently available drugs. Amenamevir (AMNV), a new drug targeting the viral helicase-primase (HP) enzyme complex, with proven efficacy for treatment of herpetic infections of other sites, has recently shown value in the management of ACV-resistant HK. Its TK-independent mechanism allows it to retain its antiviral activity even in cases of patient resistance to ACV.

Exploring 4-quinolone-3-carboxamide derivatives: A versatile framework for emerging biological applications

4-Quinolones are a pivotal class of compounds derived from the quinoline core, recognized for their broad therapeutic applications. Originating from the synthesis of chloroquine, their discovery led to nalidixic acid, the first quinolone analog to exhibit antibacterial activity, catalyzing the development of fluoroquinolones. Beyond their role as antibiotics, 4-quinolone derivatives have emerged as versatile scaffolds with demonstrated antitumor, antiviral, and antiparasitic activities, among others. Concurrently, the carboxamide functional group has gained prominence in medicinal chemistry due to its structural versatility and bioisosteric potential. Its unique properties, such as conformational stability and dual hydrogen bond capabilities, enable diverse pharmacodynamic interactions. The combination of these two structural fragments has proven to be a powerful tool for the discovery of new bioactive prototypes. This review consolidates advancements in the exploration of 4-quinolone-3-carboxamide derivatives, emphasizing their multifaceted biological activities and the innovative strategies driving their optimization. Key highlights include their potential as kinase inhibitors, antiviral agents, and anticancer therapeutics. By synthesizing insights from recent studies, this review underscores the relevance of this framework in addressing contemporary medicinal challenges.

Animal models of human herpesvirus infection

Human herpesvirus, a specific group within the herpesvirus family, is responsible for a variety of human diseases. These viruses can infect humans and other vertebrates, primarily targeting the skin, mucous membranes, and neural tissues, thereby significantly impacting the health of both humans and animals. Animal models are crucial for studying virus pathogenesis, vaccine development, and drug testing. Despite several vaccine candidates being in preclinical and clinical stages, no vaccines are current available to prevent lifelong infections caused by these human herpesviruses, except for varicella-zoster virus (VZV) vaccine. However, the strict host tropism of herpesviruses and other limitations mean that no single animal model can fully replicate all key features of human herpesvirus-associated diseases. This makes it challenging to evaluate vaccines and antivirals against human herpesvirus comprehensively. Herein, we summarize the current animal models used to study the human herpesviruses including α-herpesviruses (herpes simplex virus type 1(HSV-1), HSV-2, VZV), β-herpesviruses (human cytomegalovirus (HCMV), γ-herpesviruses (Epstein-Barr virus (EBV)) and Kaposi's sarcoma herpesvirus (KSHV)). By providing concise information and detailed analysis of the potential, limitations and applications of various models, such as non-human primates, mice, rabbits, guinea pigs, and tree shrews, this summary aims to help researchers efficiently select the most appropriate animal model, offering practical guidance for studying human herpesvirus.

Association between herpesviruses and alzheimer's disease: a meta-analysis based on case-control studies

Herpesviruses infection has been found to be implicated in the etiology of Alzheimer's disease (AD). However, the results remain controversial. This systematic meta-analysis was aimed to evaluate the relationship between Herpesviruses infection and the risk of developing AD. Relevant literature was searched from five databases, including CNKI, PubMed, Web of Science, Embase, and Cochrane Library, to obtain case-control studies (published between the date of database establishment and February 2025; no language restrictions) that compared the Herpesviruses positivity in AD patients and healthy controls. Among all existing studies, there are more abundant published case-control studies on the relationship between HSV-1, HCMV and Alzheimer's disease. Therefore, we chose these two viruses to further explore their association with Alzheimer's disease. The quality of the included studies was evaluated by the NOS scale. The Review Manager 5.3 software was used to calculate the odds ratio (OR) and 95% confidence interval (95% CI) for meta-analysis. Publication bias was investigated using the funnel plots, Begg's and Egger's publication bias plots. Twenty-one eligible studies were included to investigate the association between HSV-1 and AD. The results of the meta-analysis indicated that HSV-1 infection is a risk factor for AD (OR = 1.39, 95% CI = (1.14-1.69), P < 0.05)). In the subgroup analysis, the pooled ORs of HSV-1 infection associated with AD were 1.28 (95% CI: 0.74-2.22) in literature prior to 2010;1.44 (95% CI: 1.14-1.82) in literature after 2010; 1.27(95% CI: 1.01-1.60) in studies from Europe; 1.22(95% CI: 0.66-2.27) in studies from North America;1.89 (95% CI: 1.19-3.02) in studies from Asia; 1.38 (95% CI: 1.10-1.74) in the clinical diagnosis group; 1.52 (95% CI: 0.84-2.74) in the autopsy group. The pooled OR of APOE4 positivity and AD risk was 5.51 (95% CI: 4.33-7.01). The association between HCMV and AD was analyzed in seven studies. The pooled result showed that HCMV infection is not a risk factor for AD (OR = 0.83, 95% CI = 0.63-1.09). Our latest meta-analysis suggests that HSV-1 infection is a risk factor for the risk of AD. Therefore, anti-HSV-1 infection can serve as a potential therapeutic strategy for control of AD incidence. There is insufficient evidence to support association between HCMV and AD.

Daxx and HIRA go viral - How chromatin remodeling complexes affect DNA virus infection

Daxx and HIRA are key proteins in the host response to DNA virus infections. Daxx is involved in apoptosis, transcription regulation, and stress responses. During DNA virus infections, Daxx helps modulate the immune response and viral progression. Viruses like adenoviruses and herpesviruses can exploit Daxx to evade immune detection, either by targeting it for degradation or inhibiting its function. Daxx also interacts with chromatin to regulate transcription, which viruses can manipulate to enhance their own gene expression and replication. HIRA is a histone chaperone and reported to be essential for chromatin assembly and gene regulation. It plays a critical role in maintaining chromatin structure and modulating gene accessibility. During DNA virus infection, HIRA influences chromatin remodeling, affecting both viral and host DNA accessibility, which impacts viral replication and gene expression. Additionally, the histone variant H3.3 is crucial for maintaining active chromatin states. It is incorporated into chromatin independently of DNA replication and is associated with active gene regions. During viral infections, H3.3 dynamics can be altered, affecting viral genome accessibility and replication efficiency. Overall, Daxx and HIRA are integral to orchestrating viral infection programs, maintaining latency and/or persistence, and influencing virus-induced transformation by modulating chromatin dynamics and host immune responses, making them significant targets for therapeutic strategies once fully understood. Here, we summarize various DNA viruses and their crosstalk with Daxx and HIRA.

Global research trend of Herpes simplex keratitis: a bibliometric analysis and visualization from 1941 to 2024

Objective

Herpes simplex keratitis (HSK), caused by the herpes simplex virus (HSV), is a leading cause of infectious blindness worldwide. This study aims to explore the research trends, key contributors, and emerging areas of focus in HSK research through bibliometric analysis.

Methods

Publications related to HSK from 1941 to 2024 were retrieved from the Web of Science Core Collection (WoSCC). Bibliometric and visual analyses were conducted using VOSviewer, CiteSpace, and R 4.3.3.

Results

A total of 1,076 publications on HSK were identified. The top three contributing countries were the United States (267 papers), China (99), and Japan (64). Harvard University was the leading institution with 75 publications, while the American Journal of Ophthalmology emerged as the most influential journal, boasting an h-index of 29. Kaufman, HE, was the most cited author, with 1,988 citations. The top three keywords were "infection" (82), "stromal keratitis" (73), and "penetrating keratoplasty" (62). Burst keyword analysis indicated a growing interest in terms such as "outcome" and "ultraviolet A" since 2018.

Conclusion

This bibliometric analysis underscores two primary research areas in HSK: the clinical management of stromal keratitis and infection, as well as the mechanisms of HSK recurrence, which include strategies for preventing reactivation and managing immune rejection. Future research is anticipated to focus on innovative treatments, particularly ultraviolet A therapy.

The combined effects of HSV-1 glycoprotein D and aluminum hydroxide on human neuroblastoma cells: Insights into oxidative DNA damage, apoptosis, and epigenetic modifications

Herpes simplex virus type 1 (HSV-1) infections are a significant global health concern due to the virus's ability to evade apoptosis and establish lifelong latency in the peripheral nervous system. The specific viral components responsible for these effects remain unclear, necessitating individual examination of their molecular impacts. This study focused on investigating the effects of recombinant HSV-1 glycoprotein D (HSV-1 gD), a viral protein essential for host cell entry, and/or aluminum hydroxide, a known neurotoxic agent, on reactive oxygen species (ROS) production, apoptotic markers, and epigenetic modifications in SH-SY5Y neuroblastoma cells. Using inhibitory concentration 20 (IC20) values for HSV-1 gD and aluminum hydroxide, experimental groups were established. Intracellular ROS levels, oxidative DNA damage, and the expression and activity of key apoptotic proteins were measured. Additionally, global DNA methylation, histone H3 and H4 acetylation, and the activities of histone deacetylases (HDAC3 and HDAC8) were evaluated. Results of the study showed that both HSV-1 gD and aluminum hydroxide independently increased ROS production and induced apoptosis in SH-SY5Y cells. Notably, significant alterations in epigenetic markers were observed, including decreased global DNA methylation and histone acetylation levels. These epigenetic modifications suggest potential underlying mechanisms for the neurotoxic effects of aluminum hydroxide and HSV-1 gD. In addition to the traditional suggestions for HSV-1 gD as an anti-apoptotic factor, our findings indicate that it may also contribute to neurotoxicity. This study provides new insights into the molecular interactions between viral components and neurotoxic agents and emphasizes the importance of epigenetic regulation in neuronal cell death.

A child who suffered from HSV encephalitis and AE with positive anti-MOG results: a case report

OBJECTIVE

To investigate the clinical manifestations of a pediatric case involving herpes simplex virus (HSV) encephalitis concurrent with autoimmune encephalitis (AE), which is characterized by a positive anti-myelin oligodendrocyte glycoprotein (MOG) antibody status.

RESULTS

A 12-year-old girl initially presented with symptoms of autoimmune encephalitis, including weakness and poor appetite, followed by headache, dizziness, and personality changes, which are indicative of disease progression. Cerebrospinal fluid routine biochemical tests demonstrated abnormal results. Cerebrospinal fluid mNGS results demonstrated human herpesvirus type I, and autoimmune encephalitis antibody tests suggested a positive result for anti-myelin oligodendrocyte glycoprotein (MOG) antibodies (1:100). Brain MRI revealed abnormal signals in the bilateral frontal lobes and dorsal thalamus. Therefore, diagnoses of herpes simplex virus encephalitis and autoimmune encephalitis were determined. After treatment with acyclovir, gamma globulin and hormones, the patient exhibited significant improvement in her symptoms.

CONCLUSIONS

Children with herpes simplex virus encephalitis combined with autoimmune encephalitis may present with atypical clinical symptoms, and a positive anti-MOG antibody test is rarely observed, with no previous reports on this occurrence. The early detection of the relevant pathogens (in addition to timely reevaluation) can aid in accurate diagnosis. Moreover, antiviral and immunosuppressive therapy may significantly improve symptoms and patient prognosis.

Analysis of the Interaction Between the Attenuated HSV-1 Strain M6 and Macrophages Indicates Its Potential as an Effective Vaccine Immunogen

Herpes simplex virus type 1 (HSV-1) is a very concerning pathogen due to its ability to persist in the host's nervous system and continuously interfere with the immune system, which complicates treatment. Therefore, the development of an effective HSV-1 vaccine is crucial. In this study, we focused on an HSV-1 mutant strain, M6, which includes several deleted genes associated with viral infection virulence and latent infection function, and explored its infection of macrophages and immunological characteristics. The study found that both the attenuated strain M6 and the wild-type strain infect macrophages through the binding of the gD protein to the HVEM receptor on the macrophage surface. Compared to the wild-type strain, the attenuated M6 strain induced a milder immune response, characterized by the lower expression of immune signaling molecules and inflammatory cytokine levels. Upon reintroducing macrophages infected with the two strains into mice, the M6 strain induced lower levels of inflammatory cytokines and higher levels of chemokines in spleen cells and also slightly lower humoral and cellular immune responses than the wild-type strain. Further histopathological analysis revealed that mice in the attenuated M6 group showed more stable body weight changes and milder pathological damage in immune organs such as the liver, spleen, and lymph nodes. In conclusion, the attenuated M6 strain exhibits good immunogenicity and mild pathological side effects, suggesting its potential as an effective immunogen.

Plasma proteins and herpes simplex virus infection: a proteome-wide Mendelian randomization study

Proteomics plays a pivotal role in clinical diagnostics and monitoring. We conducted proteome-wide Mendelian randomization (MR) study to estimate the causal association between plasma proteins and Herpes simplex virus (HSV) infection. Data for 2,923 plasma protein levels were obtained from a large-scale protein quantitative trait loci study involving 54,219 individuals, conducted by the UK Biobank Pharma Proteomics Project. HSV-associated SNPs were derived from the FinnGen study, which included a total of 400,098 subjects infected with HSV. MR analysis was performed to assess the links between protein levels and the risk of HSV infection. Furthermore, a Phenome-wide MR analysis was utilized to explore potential alternative indications or predict adverse drug events. Finally, we evaluated the impact of 1,949 plasma proteins on HSV infection, identifying 48 proteins that were negatively associated with HSV infection and 54 proteins that were positively associated. Genetically higher HLA-E levels were significantly associated with increased HSV infection risk (OR = 1.39, 95% CI: 1.17-1.65, P = 2.13 × 10-4, while ULBP2 showed a significant negative association with HSV infection risk (OR = 0.81, 95% CI: 0.73-0.90, P = 6.25 × 10-5) in the primary analysis. No significant heterogeneity or pleiotropy was observed in any of the results. Additionally, we found a suggestive association of Lymphotoxin-beta, SMOC1, MICB_MICA, ASGR1, and ANXA10 with HSV infection risk (P < 0.003). In Phenome-wide MR analysis, HLA-E was associated with 214 phenotypes (PFDR < 0.10) while ULBP2 did not show significant associations with any diseases after FDR adjustment. The comprehensive MR analysis established a causal link between multiple plasma proteins and HSV infection, emphasizing the roles of HLA-E and ULBP2. These results provide new insights into the biological mechanisms of HSV and support the potential for early intervention and treatment strategies, although further research is needed to validate these plasma protein biomarkers.

Immune Modulatory Effects of Vitamin D on Herpesvirus Infections

In addition to its classical role in calcium and phosphate metabolism regulation, vitamin D also has an important impact on immunity modulation. Vitamin D regulates the immune response, shifting from a proinflammatory state to a more tolerogenic one by increasing the release of anti-inflammatory cytokines while downregulating proinflammatory cytokines. Thus, low levels of vitamin D have been associated with an increased risk of developing autoimmune diseases like multiple sclerosis and type 1 diabetes. Furthermore, this prohormone also enhances the release of well-known antimicrobial peptides, like cathelicidin LL-37 and β-defensins; therefore, it has been proposed that vitamin D serum levels might be related to the risk of well-known pathogen infections, including herpesviruses. These are a group of widely spread viral pathogens that can cause severe encephalitis or tumors like Kaposi's sarcoma and Burkitt lymphoma. However, there is no consensus on the minimum levels of vitamin D or the recommended daily dose, making it difficult to establish a possible association between these two factors. This narrative non-systematic review will analyze the mechanisms by which vitamin D regulates the immune system and recent studies about whether there is an association between vitamin D serum levels and herpesvirus infections.

Clinical strategies to prevent recurrence of Herpes simplex and Herpes zoster following ocular surgery: A comprehensive review with practical guidelines

Recurrences of herpetic infections following intraocular surgeries pose a threat to optimal surgical outcomes. The high prevalence of herpetic diseases require ophthalmologists to be familiar with the special measures in the surgery of these patients. A thorough preoperative assessment and meticulous postoperative surveillance should be tailored for each patient, depending on the surgery and the risk of virus reactivation. We compile the relevant evidence in the literature and provide a comprehensive review of the preoperative assessment and postoperative diagnostic clues and management of the herpetic infections following different types of intraocular surgeries, including cataract surgery, keratoplasty, corneal crosslinking, glaucoma, and refractive surgeries.

Targeting Herpes Simplex Virus Glycoprotein D with Bispecific Antibodies: Expanding Therapeutic Horizons by Searching for Synergy

Herpes simplex viruses (HSV-1 and HSV-2), which can be transmitted both orally and sexually, cause lifelong morbidity and in some cases, meningitis and encephalitis. While both the passive transfer of neutralizing antibodies and placental transfer of anti-HSV monoclonal antibodies (Mabs) have shown therapeutic promise in animal models, clinical trials have yet to identify approved immunotherapeutics for herpes infection. Here, we present strategies for the generation of recombinant bispecific antibodies (BsAbs) that target different domains of glycoprotein D (gD), crucial for HSV entry, that have the potential to outperform the effect of individual Mabs to curb herpes infection. Specifically, we selected three pairs of Mabs from our extensive panel for BsAb design and production based on their binding site and ability to block virus entry. Actual binding of BsAbs to gD and epitope availability on gD after BsAb binding were characterized using surface plasmon resonance (SPR) and inhibition by IgG Fab fragments generated from selected Mabs. While one BsAb exhibited an additive effect similar to that observed using a combination of the Mabs utilized for its generation, two showed antagonistic effects, suggesting that the simultaneous engagement of two epitopes or selective binding to one affected their activity against HSV. One BsAb (DL11/1D3) targeting the binding site for both nectin-1 and HVEM receptors demonstrated synergistic inhibitory activity against HSV, outperforming the effect of the individual antibodies. Recombinant DL11/1D3 antibody variants, in which the size of one or both paratopes was decreased to single chains (scFv-Fc), highlighted differences in potency depending on antibody size and format. We propose that BsAbs to individual glycoproteins offer a potential avenue for herpes therapeutics, but their design, mechanism of action, antibody format, and epitope engagement require careful consideration of structure for optimal efficacy.

Early Intervention in Herpes Simplex Virus-1 Replication in Vitro with Allenic Macrolide Archangiumide

Archangiumide is a unique macrolide natural product that features an endocyclic allene functionality, rendering it a prototype of a new class of secondary metabolites of microbial origin. However, its biological and/or pharmaceutical roles remain obscure. In this study, we have unveiled an antiviral potency of archangiumide that was effective against herpes simplex virus (HSV-1) replication. We found that archangiumide did not affect host cell viability, nor pathogen infectivity, but suppressed HSV-1 early replication, in terms of early replication genes, such as ICP0, ICP4, etc. Further scrutinizing the underlined master regulator, we found that HSV-1 VP16 protein expression was inhibited by archangiumide, as well as VP16 nuclear translocation. As VP16 is a coactivator of transcription, archangiumide harnessed the master regulator of HSV-1 early replication. Together, here we provide evidence that allene macrolide archangiumide possesses robust antiviral functions that may be valuable for a novel viral infection intervention, as macrolides are generally safe drugs for prolonged treatments.

Association between dietary inflammation index and herpes simplex virus I and II: A cross-sectional study

INTRODUCTION

We aimed to fill the research gap between DII and herpes simplex virus infection among adults in the US by analyzing the association between dietary inflammatory index and herpes simplex virus and to provide new ideas for herpes simplex virus prevention and treatment.

METHOD

We used data from 8636 participants in NHANES 2007-2016, which were statistically analyzed by participant baseline study, one-way analysis of variance, multiple regression equations, smoothed curve fitting, and stratified analysis.

RESULT

In the fully adjusted model, the DII high concentration group was positively associated with the prevalence of herpes simplex (1.15 (0.89, 1.48), p = 0.0027), and the results of the stratified analyses indicated that the positive association between DII and herpes simplex virus type II was stable in the population.

CONCLUSION

This study demonstrates a positive association between DII and herpes simplex virus II in US adults, suggesting that a proinflammatory diet may be an independent risk factor for herpes simplex virus II.

Oncolytic Viruses in Ovarian Cancer: Where Do We Stand? A Narrative Review

Ovarian cancer (OC) remains the most lethal gynecologic malignancy with limited effective treatment options. Oncolytic viruses (OVs) have emerged as a promising therapeutic approach for cancer treatment, capable of selectively infecting and lysing cancer cells while stimulating anti-tumor immune responses. Preclinical studies have demonstrated significant tumor regression and prolonged survival in OC models using various OVs, such as herpes simplex. Early-phase clinical trials have shown a favorable safety profile, though the impact on patient survival has been modest. Current research focuses on combining OVs with other treatments like immune checkpoint inhibitors to enhance their efficacy. We provide a comprehensive overview of the current understanding and future directions for utilizing OVs in the management of OC.

Screening for subclinical genital herpes in pregnant females - A neglected practice

Objective

The present study was aimed to screen the Herpes simplex virus (HSV) infection in cervical smears of clinically suspicious to asymptomatic pregnant women of local population.

Method

This descriptive cross-sectional study was conducted at the Department of Histopathology, University of Health Sciences Lahore, Pakistan from August 2021 to September 2022. A total of N=120 cervical smears were taken from the pregnant females of gestation age 18-38 weeks, visiting the outpatient department (OPD) of Gynecology & Obstetrics, Jinnah Hospital Lahore. Endocervical smears were taken; cell block and cytospin preparations were prepared. The cytological changes were categorized according to the updated Bethesda Classification System 2014 and the samples were screened for the presence of HSV 1 & 2 through immunocytochemistry (ICC), immunohistochemistry (IHC) and Immunofluorescence (IF). SPSS version 25.0 was used to analyze the data and p-Value of ≤ 0.05 was considered as statistically significant.

Results

Out of N=120 pregnant females, 12.5% were positive for HSV on ICC while 2.5% cases showed positive nuclear staining for HSV on cell block by IHC. On IF staining, around 7.5% samples were positive for HSV by cytospin method whereas 15% cases showed positivity for HSV on cell block method. Typical herpetic genital lesions were observed in 13% of HSV positive females (p=0.043). Pap staining of cervical smears revealed negative for intraepithelial lesion or malignancy (NILM) in 90% of the samples while 10% of the cases were suggestive of atypical squamous cells of undetermined significance (ASCUS). Moreover, 13% cases showed candida albicans on culture test. None of the subjects showed positive Trichomonas vaginalis on wet smears.

Conclusion

Early and effective diagnosis of sub-clinical cervico-vaginal HSV infection in pregnant females by adopting minimally invasive cytological techniques and immunofluorescent staining may lead to reduced morbidity and mortality.

DNA methylation landscapes before and after Pacific Oyster Mortality Syndrome are different within and between resistant and susceptible Magallana gigas

Pacific oysters face recurring outbreaks of Pacific Oyster Mortality Syndrome (POMS), a polymicrobial multifactorial disease. Although this interaction is increasingly understood, the role of epigenetics (e.g., DNA methylation) appears to be of fundamental importance because of its ability to shape oyster resistance/susceptibility and respond to environmental triggers, including infections. In this context, we comprehensively characterized basal (no infection) and POMS-induced changes in the methylome of resistant and susceptible oysters, focusing on the gills and mantle. Our analysis identified differentially methylated regions (DMRs) that revealed distinct methylation patterns uniquely associated with the susceptible or resistant phenotypes in each tissue. Enrichment analysis of genes bearing DMRs highlighted that these epigenetic changes were specifically linked to immunity, signaling, metabolism, and transport. Notably, 31 genes with well-known immune functions were differentially methylated after POMS, with contrasting methylation patterns between the phenotypes. Based on the methylome differences between phenotypes, we identified a set of candidate epibiomarkers that could characterize whether an oyster is resistant or susceptible (1998 candidates) and whether a site has been exposed to POMS (164 candidates). Overall, the findings provide a deeper understanding of the molecular interactions between oysters and POMS infection, opening new questions about the broader implications of epigenetic mechanisms in host-pathogen dynamics and offering promising strategies for mitigating the impacts of this devastating disease. Beyond its biological aspects, this study provides insights into potential epigenetic biomarkers for POMS disease management and targets for enhancing oyster health and productivity.

Late-Onset HSV-2 Encephalitis in a Kidney Transplant Recipient: A Rare Case Report

Infections are an important cause of morbidity and mortality in renal transplant recipients. Among the viral pathogens encountered in this population, herpes simplex virus (HSV), a member of the Alphaherpesvirinae subfamily, has an important place. HSV type 2 infections in this immunosuppressed population are primarily due to viral reactivation. While HSV-2 frequently presents as genital herpes or remains asymptomatic, in rare cases, it can lead to severe neurological manifestations, such as encephalitis, particularly in the early post-transplant period with a reported mortality rate of up to 40%. We present the case of a 49-year-old male who, three years after kidney transplantation, developed acute neurological symptoms, including aphasia and disorientation. Polymerase chain reaction (PCR) analysis of cerebrospinal fluid (CSF) identified HSV-2 as the causative pathogen, enabling a swift and accurate diagnosis. The patient was promptly treated with intravenous acyclovir, adjusted for renal function, resulting in complete neurological recovery and subsequent negative follow-up CSF PCR results. This case emphasizes the vital role of PCR diagnostics as the gold standard for confirming viral encephalitis, particularly in immunosuppressed patients, where atypical presentations can complicate diagnosis. It also highlights the importance of considering HSV-2 encephalitis in the differential diagnosis even beyond the immediate post-transplant period. Early recognition and management, facilitated by the multidisciplinary approach, are critical for improving outcomes in this vulnerable patient population.

Tissue-resident immune cells: from defining characteristics to roles in diseases

Tissue-resident immune cells (TRICs) are a highly heterogeneous and plastic subpopulation of immune cells that reside in lymphoid or peripheral tissues without recirculation. These cells are endowed with notably distinct capabilities, setting them apart from their circulating leukocyte counterparts. Many studies demonstrate their complex roles in both health and disease, involving the regulation of homeostasis, protection, and destruction. The advancement of tissue-resolution technologies, such as single-cell sequencing and spatiotemporal omics, provides deeper insights into the cell morphology, characteristic markers, and dynamic transcriptional profiles of TRICs. Currently, the reported TRIC population includes tissue-resident T cells, tissue-resident memory B (BRM) cells, tissue-resident innate lymphocytes, tissue-resident macrophages, tissue-resident neutrophils (TRNs), and tissue-resident mast cells, but unignorably the existence of TRNs is controversial. Previous studies focus on one of them in specific tissues or diseases, however, the origins, developmental trajectories, and intercellular cross-talks of every TRIC type are not fully summarized. In addition, a systemic overview of TRICs in disease progression and the development of parallel therapeutic strategies is lacking. Here, we describe the development and function characteristics of all TRIC types and their major roles in health and diseases. We shed light on how to harness TRICs to offer new therapeutic targets and present burning questions in this field.

Analysis of the relevant factors for corneal graft rejection in the southern Liaoning region from 2019 to 2023

Background

The study aimed to review the etiology of corneal blindness and investigate the relative risk of corneal graft rejection (CGR) in the southern Liaoning region.

Methods

The clinical records of 359 patients (394 eyes) who underwent corneal transplantation at the Department of Keratoconus of the Third People's Hospital of Dalian from January 2019 to December 2023 were retrospectively analyzed. The data included patients' age, gender, occupation, diagnosis, surgical procedure, postoperative immune rejection, and neovascularization. The data were collected and descriptively analyzed to characterize the etiology of corneal blindness and to analyze the risk factors for postoperative immune rejection after corneal transplantation using logistic regression.

Results

The mean age of the patients who underwent corneal transplantation was 55.90 ± 0.80 years, and there were more male patients than female patients with corneal blindness. Infectious keratitis (41.1%) was reported as the leading cause of corneal blindness, and penetrating corneal transplantation was the main surgical procedure for the recovery of sight. Preoperative corneal vascularization and penetrating corneal graft rejection were identified as risk factors for immune rejection of corneal grafts. The preoperative corneal vascularization was performed (p = 0.044, OR = 2.607). Penetrating keratoplasty (PKP) was performed (p = 0.024, OR = 1.953), and deep anterior lamellar keratoplasty was also performed (p = 0.801, OR = 1.088). Viral infections (p < 0.001, OR = 16.871) were the major risk factor for preoperative corneal neovascularization (CNV) compared to other etiologies, such as fungal infections (p < 0.001, OR = 0.018), mechanical ocular trauma (p < 0.001, OR = 0.034), immune keratitis (p = 0.023, OR = 0.152), and endothelial dysfunction (p < 0.001, OR = 0.054).

Conclusion

Infectious keratitis was identified as the major cause of corneal blindness in the southern Liaoning region over the past 5 years. Penetrating keratoplasty and preoperative corneal vascularization were the risk factors for corneal graft rejection. In addition, virus-derived keratitis was considered to be the main risk factor for corneal neovascularization, and deep anterior lamellar keratoplasty was not found to have an effect on corneal graft rejection in this study.

Alphaherpesvirus in Pets and Livestock

Herpesviruses are a group of DNA viruses capable of infecting multiple mammalian species, including humans. This review primarily summarizes four common alphaherpesviruses found in pets and livestock (feline, swine, canine, and bovine) in aspects such as epidemiology, immune evasion, and latency and reactivation. Despite the fact that they primarily infect specific hosts, these viruses have the potential for cross-species transmission due to genetic mutations and/or recombination events. During infection, herpesviruses not only stimulate innate immune responses in host cells but also interfere with signaling pathways through specific proteins to achieve immune evasion. These viruses can remain latent within the host for extended periods and reactivate under certain conditions to trigger disease recurrence. They not only affect the health of animals and cause economic losses but may also pose a potential threat to humans under certain circumstances. This review deepens our understanding of the biological characteristics of these animal alphaherpesviruses and provides an important scientific basis for the prevention and control of related diseases.

Seroprevalence of HSV-2 in multiple subgroups of infertile men with abnormal sperm parameters and those seeking sex selection: a case-control study

BACKGROUND

Herpes simplex virus type 2 (HSV-2) is a common sexually transmitted infection (STI) primarily acquired through sexual contact. In 2000, the World Health Organization (WHO) for the first time reported the association of STIs with male infertility. Infertility is described as the inability to achieve a clinical pregnancy after engaging in regular, unprotected sexual intercourse for a year or more. HSV-2 infection is a significant concern for infertility, with evidence suggesting it can contribute to a range of reproductive complications. The seroprevalence of HSV-2 among infertile men in Iran has not yet been determined. Therefore, we conducted a case-control study to examine the seroprevalence of HSV-2 in multiple subgroups of infertile men with abnormal sperm parameters (Case) and individuals seeking sex selection services and those with normal sperm parameters (Control).

METHOD

Blood samples were collected from infertile males seeking fertility treatment, and those seeking sex selection at the Avicenna Infertility Clinic in Tehran, Iran between July 2023 and February 2024. Demographic and clinical data were collected through a questionnaire. Anti-HSV-2 IgG antibodies (Abs) were detected using a commercially available ELISA kit [Herpes simplex 2 (gG2 purified), Vircell, Spain].

RESULTS

Of the 486 samples that met the eligibility criteria, 420 were tested. The ELISA testing was performed on 98 control, 32 Teratozoospermia (T), 45 Asthenozoospermia (A), 48 Oligoteratozoospermia (OTA), 50 Azoospermia (Azo), and 147 Teratozooasthenospermia (TA) samples. Thirteen samples came out positive for HSV-2 IgG Abs (3.41% case and 2.04% control group). Of these 13 positive samples, 7 were from the TA group, 2 from the T group, 2 from the Azo group, and 2 control. The age (43.15 ± 5.10 vs. 37.74 ± 6.20, p = 0·0020) and marriage duration (12.54 ± 6.88 vs. 8.12 ± 4.95, p = 0·0019) were significantly higher in the HSV-2 IgG Ab positive group.

CONCLUSION

The results of this study enhance our understanding of the epidemiology of HSV-2 in individuals seeking infertility treatment. It can be inferred that the seroprevalence of HSV-2 IgG among patients referring to an infertility treatment clinic in Tehran is relatively low. The study also indicates that the chance of HSV-2 infection increases with age. The highest number of positive cases in the TA suggests that HSV-2 may adversely affect sperm motility and morphology.

Epidemiological trends of HSV-1 and HSV-2 Central Nervous System Infections: A Retrospective Analysis from 2018 to 2023 from Saudi Arabia

Herpes Simplex Virus (HSV) types 1 and 2 are significant etiologies to central nervous system (CNS) infections, leading to potential severe neurological consequences. Despite their global impact, our region's data on the epidemiology of HSV CNS infections remains limited. This study assessed the epidemiology and diagnostic trends of HSV-1 and HSV-2 CNS infections in a tertiary hospital in Southwestern Saudi Arabia from 2018 to 2023. A retrospective study was conducted using data from cerebrospinal fluid (CSF) samples collected from patients with suspected CNS infection between 2018 and 2023. Polymerase Chain Reaction (PCR) results for detecting HSV-1 and HSV-2, performed as part of routine clinical diagnostics, were analyzed. Data on patient demographics, specimen collection times (including months and years), laboratory processing times, and seasonal trends were collected and analyzed using descriptive statistics and univariate analysis. Of the 280 samples, 11.0% were positive for HSV, with 10.0% positive for HSV-1 and 1.0% for HSV-2. Most HSV-positive cases were found in patients aged ≥51 years (27.0%). Peak detection occurred in 2020, with seasonal spikes in May and September. The turnaround time significantly varied, with the shortest laboratory turnaround time for PCR results recorded in 2020 (35.54 hours), while the longest was in 2021 (167.38 hours). This study reports an important burden of HSV-related CNS infections in Southwestern Saudi Arabia, indicating the importance of timely diagnosis through PCR testing. Our findings highlight the need for improved diagnostic workflows and enhanced epidemiological surveillance. Future research should explore broader regional and clinical data related to HSV CNS infection epidemiology.

Viral reactivations and fungal infections in nonresolving acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a condition affecting 10% of patients requiring admission to the intensive care unit and results from endothelial dysfunction, alveolar epithelial injury and unbalanced inflammation, leading to exudative pulmonary oedema. A significant portion of these patients experience a lung injury that fails to resolve. Persistent or worsening respiratory failure beyond 5 days after the initiation of mechanical ventilation is referred to as nonresolving ARDS. Viral and fungal pathogens can exploit the hyperinflammatory environment and altered immune landscape in ARDS, perpetuating a cycle of ongoing inflammation and lung injury, thereby contributing to the progression towards and persistence of nonresolving ARDS, even in previously immunocompetent patients. This review discusses the significance, pathophysiology, diagnostic challenges and key knowledge gaps concerning various viral and fungal pathogens in nonresolving ARDS, with a particular focus on influenza-associated and COVID-19-associated pulmonary aspergillosis and pulmonary reactivation of Herpesviridae, such as cytomegalovirus and herpes simplex virus. Diagnosing these infections is challenging due to their nonspecific clinical presentation and the inability of current tests to distinguish between fungal colonisation or asymptomatic viral shedding and clinically significant infections or reactivations. A deeper understanding of the complex interplay between these pathogens and the host immune system in the context of ARDS, combined with advances in diagnostic and therapeutic strategies, has the potential to enhance the management and prognosis of patients with nonresolving ARDS.

Deletion of gE in Herpes Simplex Virus 1 Leads to Increased Extracellular Virus Production and Augmented Interferon Alpha Production by Peripheral Blood Mononuclear Cells

Herpes simplex virus (HSV) in humans and pseudorabies virus (PRV) in pigs are both alphaherpesviruses. Plasmacytoid dendritic cells (pDCs) make part of the peripheral blood mononuclear cells (PBMCs) and are specialized in producing large amounts of antiviral type I interferon (IFN-I). IFN-I production by PBMCs in response to both HSV-1 and PRV can be virtually exclusively attributed to pDCs. Recently, we discovered that cells infected with gEnull PRV trigger increased production of IFNalpha by porcine PBMCs/pDCs compared with cells infected with wild-type (WT) PRV. This increased IFNalpha response correlates with increased extracellular virus production triggered by gEnull PRV compared with WT PRV. The gE protein and some of its currently described functions are conserved in different alphaherpesviruses, including PRV and HSV-1. In the current study, we report that cells infected with gEnull HSV-1 trigger increased IFNalpha production by human PBMCs and increased extracellular virus production compared with WT HSV-1. Hence, these recently described functions of PRV gE are conserved in HSV-1 gE. Since the increased extracellular virus production and IFNalpha response have also been reported for successful (gEnull) PRV vaccines, the current findings may have important consequences for the rational design of HSV vaccines.

JAG1 mediates apoptosis in herpes simplex keratitis by suppressing autophagy via ROS/JAG1/NOTCH1/pULK1 signaling pathway

Herpes simplex keratitis (HSK), an ocular disease resulted from herpes simplex virus type 1 (HSV-1) infection, leads to the majority of infectious corneal blindness worldwide. The apoptosis of corneal epithelial cells (CECs) resulted from HSV-1 disrupts the epithelial barrier and exacerbates the infection; however, there is no definitive cure for HSK. Jagged1 (JAG1), one of the primary functional ligands for NOTCH receptors, plays a crucial role in regulating apoptosis and autophagy; however, its role in HSK is unclear. Our transcriptome analysis showed JAG1 was significantly upregulated in HSV-1-infected human CECs. We aimed to explore JAG1's role in regulating apoptosis in HSV-1-infected human CECs and in HSK mice. HSV-1 infection induced apoptosis and reactive oxygen species (ROS) generation in CECs. HSV-1 also activated the JAG1/NOTCH1 signaling pathway. The ROS scavenger N-acetylcysteine significantly mitigated these effects. Additionally, inhibiting the JAG1/NOTCH1 pathway with short hairpin RNA against JAG1 or a NOTCH1 inhibitor (N-[N-{3,5-difuorophenacetyl}-1-alanyl]-S-phenylglycine t-butyl ester [DAPT]) alleviated HSV-1-induced CEC apoptosis. Transmission electron microscopy and western blotting revealed that HSV-1 infection suppressed ULK1-mediated autophagy in CECs, while DAPT treatment enhanced autophagy by suppressing ULK1 phosphorylation. The activation of autophagy by rapamycin treatment markedly reduced ROS levels and apoptosis in HSV-1-infected CECs, revealing a synergistic effect between the suppressed autophagy and increased ROS levels, ultimately leading to apoptosis. Thus, HSV-1 induces CEC apoptosis by suppressing autophagy through ROS/JAG1/NOTCH1/pULK1 signaling pathway in vitro and in vivo, providing potential therapeutic targets for HSK.

Gene Therapy: Towards a New Era of Medicine

Over the past years, many significant advances have been made in the field of gene therapy and shown promising results in clinical trials conducted. Gene therapy aims at modifying or replacing a defective, inefficient, or nonfunctional gene with a healthy, functional gene by administration of genome material into the cell to cure genetic diseases. Various methods have been devised to do this by using several viral and non-viral vectors which are either administered by in vivo or ex vivo technique. Viral vectors are best suitable for this therapy due to their potential to invade cells and deliver their genetic material whereas non-viral vectors are less efficient than viral vectors but possess some advantages such as less immunogenic response and large gene carrying capacity. Recent advances in biotechnology such as CRISPR-Cas9 mediated genome engineering and Cancer treatment with Chimeric antigen receptor (CAR) T-cell therapy are addressed in this review. This review article also delves into some recent research studies, gene therapy trials, and its applications, laying out future hopes for gene therapy in the treatment of various diseases namely haemophilia, Muscular dystrophy, SCID, Sickle cell disease, Familial Hypercholesterolemia, Cystic Fibrosis. Additionally, it also includes various nanoformulations and clinical trial data related to gene therapy.

Herpes simplex virus-induced upregulation of inflammatory cytokines in human gingival fibroblasts

Herpes simplex virus type 1 (HSV-1) is the leading pathogen in the maxillo-facial region, affecting millions of individuals worldwide. Its periodic reactivation aligns with the most common course pattern of periodontal disease. The present study used RNA sequencing to investigate the transcriptomes of human gingival fibroblasts (HGFs) following HSV-1 infection from the early to late stages (12-72 h). At the early stage of infection (12 h post-infection), the most upregulated genes were interferon (IFN) regulatory factor family members, toll-like receptor (TLR) family members, IFN-β1, interleukin (IL)-1, C-C motif ligands, chemokine (C-X-C motif) ligands (CXCLs), and tumor necrosis factor (TNF). The strongest differential expression was observed in TNF, nucleotide-binding oligomerization domain-like receptor (NLR), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathways. At the late stage of infection, the most upregulated genes were CXCLs and ILs. The differentially expressed genes were divided into nine clusters, according to the time series expression trend. Next, the prominent activation of TLRs, retinoic acid-inducible gene I-like receptor signaling, NLRs, and downstream IFNAR-JAK-STAT signaling pathways were observed via a modified HSV-1 infection map. The HSV-1-induced upregulation of inflammatory cytokines in HGFs may drive inflammatory processes in periodontitis. The dynamic variations in mRNAs in HGFs from the early to late stages after HSV-1 infection can provide an analytical framework for determining the host anti-viral defense response to antagonize HSV-1 infection in periodontal tissues.

Immune Response Elicited by Recombinant Adenovirus-Delivered Glycoprotein B and Nucleocapsid Protein UL18 and UL25 of HSV-1 in Mice

Due to the complex pathogenic and immune escape mechanisms of herpes simplex virus type 1 (HSV-1), especially the failure of induced immune responses to block the initial cell-to-cell transmission of the virus from skin cells to neurons, the body struggles to establish effective prevention and control methods, resulting in the failure of currently developed vaccines. Previous studies have highlighted the crucial roles of surface glycoproteins and nucleocapsid proteins in activating the body's immune defense system against HSV-1 infection. In this study, recombinant adenoviruses were used as vectors to generate adenoviruses carrying the nucleocapsid protein genes UL18 and UL25, as well as the surface glycoprotein gene gB. This approach aimed to mimic the protein expression process that occurs following viral infection of the host and to investigate the immune response characteristics induced by UL18, UL25, and gB proteins. The findings revealed that UL18, UL25, and gB proteins could all trigger the expression of genes associated with innate immune responses; however, the specific genes induced varied in type and level. Furthermore, all three proteins were capable of promoting the proliferation of CD8+ T cells in the lymph nodes. Notably, only UL18 and gB could elicit a Th1 cell immune response. Interestingly, among these proteins, only UL18 could also induce a relatively higher IL-4 level, indicating a Th2 cell immune response. In addition to cellular immunity, all three proteins stimulated the production of specific IgG antibodies. Notably, UL18 induced higher and more sustained levels of specific IgG antibodies in mice. By contrast, only glycoprotein gB induced lower levels of neutralizing antibodies in mice. Moreover, when these mice were challenged with HSV-1, the co-immunization with UL18 and gB provided better protection than gB alone. In conclusion, HSV-1 surface glycoproteins and nucleocapsid proteins exhibit differences in their ability to induce innate and adaptive immunity in the body, suggesting potential avenues for vaccine design by leveraging their complementary advantages.

West Nile virus encephalitis: Clinical characteristics and a comparison to other infectious encephalitides

PURPOSE

To compare functional outcomes and help differentiate between important causative agents of acute infectious encephalitis in adults, focusing on West Nile virus encephalitis (WNVE).

METHODS

The electronic database of Tel Aviv Medical Center was screened for patients admitted during 2010-2020 with acute encephalitis. Additionally, patient laboratory results during the same period were screened for CSF samples positive for common pathogens causing encephalitis. The main patient groups were compared in terms of clinical characteristics and functional outcomes.

RESULTS

One hundred and five infectious encephalitis patients were identified. WNVE patients (n = 31) and VZV encephalitis (VZVE) patients (n = 31) were older than HSV1 encephalitis (HSV1E) patients (n = 15) (median ages 73, 76, 51, respectively). WNVE patients had a more prominent inflammatory profile. CSF characteristics significantly differed between groups, with an extreme mononuclear white blood cell predominance in VZVE patients (median 98%). Functional outcomes at discharge were significantly worse in WNVE patients (median modified Rankin Scale score 4 at hospital discharge, 2.5 at last follow-up) when compared with HSV1E patients (2.5, 1, respectively) and VZVE patients (1.5, 1, respectively).

CONCLUSION

In odds with previous reports, WNVE and VZVE in this study were far more prevalent than HSV1E. Differences in clinical characteristics could prove clinically useful early in encephalitis, including an association of WNVE with a relatively prominent inflammatory profile (somewhat resembling a bacterial infection) and an extreme mononuclear white blood cell predominance in VZVE. The detrimental outcome of WNVE emphasizes the need to advance research on WNV infection.

Sociodemographic factors and comorbidities are associated with an elevated risk of herpes simplex keratitis: a population-based study in Taiwan

To investigate the association among comorbidities, sociodemographic factors, and herpes simplex keratitis (HSK). This nationwide, population-based, retrospective, matched case-control study included 27,651 patients with HSK identified from the Taiwan National Health Insurance Research Database based on the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 054.42 for dendritic keratitis and 054.43 for herpes simplex disciform keratitis. The age-, sex-, and index date-matched control group included 27,651 non-HSK individuals selected from the Taiwan Longitudinal Health Insurance Database 2000. Associations between HSK, sociodemographic conditions, and comorbidities were examined using univariate logistic regression analyses, and paired t-tests were used for continuous variables. Adjusted logistic regression was used to compare odds ratios (OR) for HSK development. Patients with corneal abrasion were more likely to develop HSK than controls [OR, 402.80; 95% confidence interval (CI), 167.47-968.79; P < 0.0001] even after conditional logistic regression (adjusted OR, 407.36; 95% CI, 169.35-979.89; P < 0.0001). Other conditions that increase the odds of HSK development include systemic diseases such as hyperlipidemia, diabetes mellitus, coronary artery disease, chronic renal disease, and human immunodeficiency virus infection. Regarding sociodemographic factors, >50% of patients with HSK were aged ≥55 years. Moreover, patients living in Northern Taiwan and metropolitan cities had higher odds of developing HSK. HSK is significantly associated with corneal abrasion, hyperlipidemia, diabetes mellitus, coronary artery disease, chronic renal disease, and human immunodeficiency virus infection.

A Better Understanding of the Clinical and Pathological Changes in Viral Retinitis: Steps to Improve Visual Outcomes

Infectious retinitis, though rare, poses a significant threat to vision, often leading to severe and irreversible damage. Various pathogens, including viruses, bacteria, tick-borne agents, parasites, and fungi, can cause this condition. Among these, necrotizing herpetic retinitis represents a critical spectrum of retinal infections primarily caused by herpes viruses such as varicella-zoster virus (VZV), herpes simplex virus (HSV), and cytomegalovirus (CMV). This review underscores the retina's susceptibility to viral infections, focusing on the molecular mechanisms through which herpetic viruses invade and damage retinal tissue, supported by clinical and preclinical evidence. We also identify existing knowledge gaps and propose future research directions to deepen our understanding and improve therapeutic outcomes.

An updated review of HSV-1 infection-associated diseases and treatment, vaccine development, and vector therapy application

Herpes simplex virus type 1 (HSV-1) is a globally widespread virus that causes and associates with a wide range of diseases, including herpes simplex encephalitis, herpes simplex keratitis, and herpes labialis. The interaction between HSV-1 and the host involves complex immune response mechanisms, including recognition of viral invasion, maintenance of latent infection, and triggering of reactivation. Antiviral therapy is the core treatment for HSV-1 infections. Meanwhile, vaccine development employs different strategies and methods, and several promising vaccine types have emerged, such as live attenuated, protein subunit, and nucleic acid vaccines, offering new possibilities for the prevention of HSV-1 infection. Moreover, HSV-1 can be modified into a therapeutic vector for gene therapy and tumour immunotherapy. This review provides an in-depth summary of HSV-1 infection-associated innate and adaptive immune responses, disease pathogenesis, current therapeutic approaches, recent advances in vaccine development, and vector therapy applications for cancer treatment. Through a systematic review of multiple aspects of HSV-1, this study aims to provide a comprehensive and detailed reference for the public on the prevention, control, and treatment of HSV-1.

Unveiling shared therapeutic targets and pathological pathways between coronary artery disease and major depressive disorder through bioinformatics analysis

Coronary artery disease (CAD) is a predominant cardiovascular condition influenced by risk factors, with an emphasis on major depressive disorder (MDD). However, the shared mechanisms and therapeutic targets for CAD and MDD remain incompletely comprehended. Functional enrichment analyses were conducted to investigate the pathways associated with the differentially expressed genes (DEGs) in the CAD and MDD datasets. Hub genes were identified utilizing the Protein-Protein Interaction network and Cytoscape software. The single sample gene set variation analysis was applied to assess immune cell infiltration in the CAD and MDD datasets. Weighted gene co-expression network analysis and molecular biological experiments were executed to evaluate these hub genes. Molecular docking was conducted to identify drug candidates targeting these hub genes. The overlapping DEGs between the CAD and MDD datasets were mainly enriched in the Herpes simplex virus 1 infection and the NF-kappa B signaling pathways. CDC42, NDUFB3, and TXN were validated within the eigengenes of the blue module, which exhibited a significant association with the CAD phenotype. The drug candidate GS-9620 was identified as a potential protective agent against both disorders. In conclusion, CDC42, NDUFB3, and TXN held potential as molecular biomarkers and therapeutic targets for the simultaneous treatment of CAD and MDD.

RNA Modifications in Pathogenic Viruses: Existence, Mechanism, and Impacts

RNA modification is a key posttranscriptional process playing various biological roles, and one which has been reported to exist extensively in cellular RNAs. Interestingly, recent studies have shown that viral RNAs also contain a variety of RNA modifications, which are regulated dynamically by host modification machinery and play critical roles in different stages of the viral life cycle. In this review, we summarize the reports of four typical modifications reported on viral RNAs, including N6-methyladenosine (m6A), 5-methylcytosine (m5C), N4-acetylcytosine (ac4C), and N1-methyladenosine (m1A), describe the molecular mechanisms of these modification processes, and illustrate their impacts on viral replication, pathogenicity, and innate immune responses. Notably, we find that RNA modifications in different viruses share some common features and mechanisms in their generation, regulation, and function, highlighting the potential for viral RNA modifications and the related host machinery to serve as the targets or bases for the development of antiviral therapeutics and vaccines.

Interest and Expectations for a Herpes Vaccine Among People Diagnosed with Genital HSV 1-2 Infection: Results from an Italian Survey

Genital herpes simplex virus (HSV) is associated with a reduction in quality of life and adverse outcomes. The aim of this study is to assess the interest and expectations for a therapeutic HSV vaccine among individuals diagnosed with genital herpes in Italy. A retrospective survey was conducted at the Infectious Diseases Unit of the IRCCS San Raffaele Scientific Institute, Milan, Italy. The study collected data on demographics, clinical history and interest in HSV vaccination. The results showed that 87.5% of participants were interested in a therapeutic vaccine, with interest higher among younger people and those with frequent genital herpes recurrences. Participants most expected the vaccine to reduce the pain associated with outbreaks, followed by a reduction in the frequency and duration of recurrences. These findings underscore the strong demand for a therapeutic HSV vaccine, especially among those who experience recurrent outbreaks, and highlight the importance of considering patient expectations when developing preventive and therapeutic strategies for genital herpes.

Control of HSV-1 Infection: Directions for the Development of CRISPR/Cas-Based Therapeutics and Diagnostics

It is estimated that nearly all individuals have been infected with herpesviruses, with herpes simplex virus type 1 (HSV-1) representing the most prevalent virus. In most cases, HSV-1 causes non-life-threatening skin damage in adults. However, in patients with compromised immune systems, it can cause serious diseases, including death. The situation is further complicated by the emergence of strains that are resistant to both traditional and novel antiviral drugs. It is, therefore, imperative that new methods of combating HSV-1 and other herpesviruses be developed without delay. CRISPR/Cas systems may prove an effective means of controlling herpesvirus infections. This review presents the current understanding of the underlying molecular mechanisms of HSV-1 infection and discusses four potential applications of CRISPR/Cas systems in the fight against HSV-1 infections. These include the search for viral and cellular genes that may serve as effective targets, the optimization of anti-HSV-1 activity of CRISPR/Cas systems in vivo, the development of CRISPR/Cas-based HSV-1 diagnostics, and the validation of HSV-1 drug resistance mutations.

Prevalence of Plantar Warts, Genital Warts, and Herpetic Infections in Greek Competitive Swimmers

Viral outbreaks are common in the sport community. Data regarding the prevalence of plantar warts, genital warts, herpes simplex type 1 (herpes labialis), herpes zoster, and genital herpes in competitive swimmers are lacking in the literature. The purpose of this study was to determine the prevalence of those viral infections among young competitive swimmers participating in Greek swimming clubs. Swimmers' parents and adult swimmers were asked to complete an anonymous questionnaire. In total, 1047 swimmers enrolled in this study. The measured parameters included gender, age, times of infections, and seasons when athletes may be more susceptible to infections. Practicing information such as type of swimming facility, number of training years, average hours of daily training, behaviors in swimming practice, and sunlight exposure was also recorded. All infections showed a significant difference in relation to "age" and "years of training". The gender significance was observed in herpes labialis (p = 0.016) and plantar warts (p = 0.05). The prevalence of all infections in swimmers who use outdoor facilities was higher. Certain behaviors such as walking barefoot on a pool deck and sharing swimming equipment correlate with herpes simplex and plantar warts. Virus infections can affect swimmers of all ages. In our study, plantar warts and herpes labialis are more common in swimmers. Herpes zoster and sexually transmitted viruses are rarer and affect adult swimmers. The impact of cutaneous infections on swimmers can affect performance and well-being. Effective prevention and management are essential to avoid complications. Proper hygiene, medical guidance, and treatment reduce swimmers' exposure to skin viruses.

A drug repurposing screen identifies decitabine as an HSV-1 antiviral

Herpes simplex virus type 1 (HSV-1) is a highly prevalent human pathogen that causes a range of clinical manifestations, including oral and genital herpes, keratitis, encephalitis, and disseminated neonatal disease. Despite its significant health and economic burden, there is currently only a handful of approved antiviral drugs to treat HSV-1 infection. Acyclovir and its analogs are the first-line treatment, but resistance often arises during prolonged treatment periods, such as in immunocompromised patients. Therefore, there is a critical need to identify novel antiviral agents against HSV-1. Here, we performed a drug repurposing screen, testing the ability of 1,900 safe-in-human drugs to inhibit HSV-1 infection in vitro. The screen identified decitabine, a cytidine analog that is used to treat myelodysplastic syndromes and acute myeloid leukemia, as a potent anti-HSV-1 agent. We show that decitabine is effective in inhibiting HSV-1 infection in multiple cell types, including human keratinocytes, that it synergizes with acyclovir, and acyclovir-resistant HSV-1 is still sensitive to decitabine. We further show that decitabine causes G > C and C > G transversions across the viral genome, suggesting it exerts its antiviral activity by lethal mutagenesis, although a role for decitabine's known targets, DNA methyl-transferases, has not been ruled out.

IMPORTANCE

Herpes simplex virus type 1 (HSV-1) is a prevalent human pathogen with a limited arsenal of antiviral agents, resistance to which can often develop during prolonged treatment, such as in the case of immunocompromised individuals. Development of novel antiviral agents is a costly and prolonged process, making new antivirals few and far between. Here, we employed an approach called drug repurposing to investigate the potential anti-HSV-1 activity of drugs that are known to be safe in humans, shortening the process of drug development considerably. We identified a nucleoside analog named decitabine as a potent anti-HSV-1 agent in cell culture and investigated its mechanism of action. Decitabine synergizes with the current anti herpetic acyclovir and increases the rate of mutations in the viral genome. Thus, decitabine is an attractive candidate for future studies in animal models to inform its possible application as a novel HSV-1 therapy.

Association between human herpes simplex virus and severe headache or migraine among aged 20-49 years: a cross-sectional study

Background and purpose

Previous studies have shown that human herpes simplex virus (HSV) infection may be associated with the onset of headache or migraine. We aimed to investigate the association between HSV infection and severe headache or migraine.

Materials and methods

The cross-sectional data on 5,730 participants aged 20-49 years were obtained from the 1999-2004 National Health and Nutrition Examination Survey (NHANES). We used weighted logistic regression analysis to assess the association between HSV infection (HSV-1 gG-1 and HSV-2 gG-2) and severe headache or migraine, and performed subgroup analyses.

Results

Our study found that women, higher education, higher body mass index, better family conditions, smoking and alcohol consumption were all associated with severe headaches or migraines. After adjusting for confounding factors such as sex, age, race, and education, HSV-2 (+) was still significantly associated with severe headache or migraine (OR = 1.22, 95%CI:1.03-1.46, p = 0.0443). In subgroup analyses, we found that participants with HSV-1 (-) and HSV-2 (+) were also significantly associated with severe headache or migraine (OR = 1.41, 95%CI:1.04-1.91, p = 0.0281).

Conclusion

HSV-2 gG-2(+) was significantly associated with severe headache or migraine.

The antimicrobial protein RNase 7 directly restricts herpes simplex virus infection of human keratinocytes

Approximately 22% of moderately to severely affected atopic dermatitis (AD) patients have a history of eczema herpeticum, a disseminated rash primarily caused by herpes simplex virus type 1 (HSV-1). Reduced activity of antimicrobial peptides may contribute to the increased susceptibility of AD patients to HSV-1. We previously demonstrated that the antimicrobial protein RNase 7 limits HSV-1 infection of human keratinocytes by promoting self-DNA sensing. Here, we addressed whether RNase 7 has any effect on HSV-1 infection when infecting keratinocytes without exogenously added costimulatory DNA, and which step(s) of the infection cycle RNase 7 interferes with. We quantified viral gene expression by RT-qPCR and flow cytometry, viral genome replication by qPCR, virucidal effects by plaque titration, and plaque formation and the subcellular localization of incoming HSV-1 particles by microscopy. Recombinant RNase 7 restricted HSV-1 gene expression, genome replication, and plaque formation in human keratinocytes. It decreased HSV-1 immediate-early transcripts independently of the induction of interferon-stimulated genes. Its main effect was on intracellular infection processes and not on extracellular virions or virus binding to cells. RNase 7 reduced the amount of cell-associated capsids and the HSV-1 envelope glycoprotein D at 3 but not at 0.5 h postinfection. Our data show that RNase 7 directly restricts HSV-1 infection of human keratinocytes, possibly by promoting the degradation of incoming HSV-1 particles. This suggests that RNase 7 may limit HSV-1 spread in the skin and that mechanisms that reduce its activity in the lesional skin of AD patients may increase their susceptibility to eczema herpeticum.

Mechanisms of ferroptosis and the relationship between ferroptosis and ER stress after JEV and HSV infection

Ferroptosis is a novel form of programmed cell death, which is different from apoptosis, pyroptosis and autophagy in morphology and biochemistry. Ferroptosis is characterized by condensed mitochondrial membrane densities, vanished of mitochondria crista and outer membrane rupture in morphology, and the accumulation of intracellular iron, lipid peroxidation (LPO), decrease of GSH and inhibition of GPX4 in biochemistry. Japanese encephalitis virus (JEV) and Herpes simplex virus (HSV) are both common neurotropic viruses that can cause neurological disorders, such as severe encephalitis. JEV and HSV have been demonstrated to be able to induce ferroptosis. This process is closely related to the inhibition of the GSH-GPX4 system, ACSL4 phosphorylation, and Nrf2 ubiquitination. In this review, we summarized the mechanisms by which JEV and HSV induced ferroptosis in the current study. In addition, we found a strong relationship between endoplasmic reticulum (ER) stress and ferroptosis, and we therefore speculated that sustained ER stress might be a prerequisite for ferroptosis in JEV and HSV-induced diseases.

Recent Advances in the Study of Alphaherpesvirus Latency and Reactivation: Novel Guidance for the Design of Herpesvirus Live Vector Vaccines

Alphaherpesviruses, including herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2), and varicella-zoster virus (VZV), infect a diverse array of hosts, spanning both humans and animals. Alphaherpesviruses have developed a well-adapted relationship with their hosts through long-term evolution. Some alphaherpesviruses exhibit a typical neurotropic characteristic, which has garnered widespread attention and in-depth research. Virus latency involves the retention of viral genomes without producing infectious viruses. However, under stress, this can be reversed, resulting in lytic infection. Such reactivation events can lead to recurrent infections, manifesting as diseases like herpes labialis, genital herpes, and herpes zoster. Reactivation is a complex process influenced by both viral and host factors, and identifying how latency and reactivation work is vital to developing new antiviral therapies. Recent research highlights a complex interaction among the virus, neurons, and the immune system in regulating alphaherpesvirus latency and reactivation. Neurotropic alphaherpesviruses can breach host barriers to infect neurons, proliferate extensively within their cell bodies, and establish latent infections or spread further. Whether infecting neurons or spreading further, the virus undergoes transmission along axons or dendrites, making this process an indispensable part of the viral life cycle and a critical factor influencing the virus's invasion of the nervous system. Research on the transmission process of neurotropic alphaherpesviruses within neurons can not only deepen our understanding of the virus but can also facilitate the targeted development of corresponding vaccines. This review concentrates on the relationship between the transmission, latency, and activation of alphaherpesviruses within neurons, summarizes recent advancements in the field, and discusses how these findings can inform the design of live virus vaccines for alphaherpesviruses.