Antiviral Drugs for EBV

Emerging drugs for Epstein-Barr virus associated-diseases

Epstein-Barr virus (EBV) is the first identified oncogenic virus. It causes three types of diseases: lymphomas, carcinomas, and autoimmune diseases. It is estimated that two hundred thousand deaths are due to EBV each year. After a primary infection, EBV can remain latent lifelong. Reactivation to lytic phase can be induced by various drugs including small organic molecules, biologics, or a combination of both. In this review, we identified the most relevant results obtained with small organic compounds against Epstein-Barr virus-associated diseases. Specific treatments targeting Epstein-Barr Nuclear Antigen 1 are emerging concerning small organic molecules and showed promising results against several EBV-related malignancies.

Repurposing Licensed Drugs with Activity Against Epstein-Barr Virus for Treatment of Multiple Sclerosis: A Systematic Approach

BACKGROUND

Epstein-Barr virus (EBV) is implicated as a necessary factor in the development of multiple sclerosis (MS) and may also be a driver of disease activity. Although it is not clear whether ongoing viral replication is the driver for MS pathology, MS researchers have considered the prospect of using drugs with potential efficacy against EBV in the treatment of MS. We have undertaken scientific and lived experience expert panel reviews to shortlist existing licensed therapies that could be used in later-stage clinical trials in MS.

METHODS

A list of therapies with anti-EBV effects was developed from existing reviews. A detailed review of pre-clinical and clinical data was undertaken to assess these candidates for potential usefulness and possible harm in MS. A 'drug-CV' and a plain language version focusing on tolerability aspects was created for each candidate. We used validated criteria to score each candidate with an international scientific panel and people living with MS.

RESULTS

A preliminary list of 11 drug candidates was generated. Following review by the scientific and lived experience expert panels, six yielded the same highest score. A further review by the expert panel shortlisted four drugs (famciclovir, tenofovir alafenamide, maribavir and spironolactone) deemed to have the best balance of efficacy, safety and tolerability for use in MS.

CONCLUSIONS

Scientific and lived experience expert panel review of anti-EBV therapies selected four candidates with evidence for efficacy against EBV and acceptable safety and tolerability for potential use in phase III clinical trials for MS.

Anti-Epstein-Barr Virus Activities of Flavones and Flavonols with Effects on Virus-Related Cancers

The Epstein-Barr virus (EBV), a member of the human gamma-herpesviruses, is intricately linked to various human malignancies. Current treatment options for EBV infection involve the use of acyclovir and its derivatives, which exhibit limited efficacy and are associated with drug resistance issues. Therefore, there is a critical need for new medications with more effective therapeutic actions and less susceptibility to resistance. This review explores the therapeutic promise of flavones and flavonols, naturally occurring molecules, against EBV and its correlated cancers. It thoroughly delves into the molecular mechanisms underlying the therapeutic efficacy of these compounds and scrutinizes their complex interplay in EBV-linked processes and cancer transformation by targeting key genes and proteins pivotal to both the viral life cycle and tumor development. Additionally, the review covers current research, highlights key findings, and discusses promising avenues for future investigations in the pursuit of targeted therapies against EBV and its related tumors.

Comprehensive Analysis Based on the TCGA Database Identified SCIN as a Key DNA Methylation-Driver Gene in Epstein-Barr Virus-Associated Gastric Cancer

An important feature of EBV-associated gastric cancer (EBVaGC) is extensive methylation of viral and host genomes. This study aims to analyze DNA methylation-driven genes (DMDG) in EBVaGC through bioinformatics methods, providing an important bioinformatics basis for the differential diagnosis and treatment of potential methylation biomarkers in EBVaGC. We downloaded the mRNA expression profiles and methylation datasets of EBVaGC and EBV-negative gastric cancer (EBVnGC) through the TCGA database to screen methylated-differentially expressed genes (MDEGs). DNA methylation-driver genes were identified based on MethylMix algorithm and key genes were further identified by LASSO regression and Random Forest algorithm. Then, we performed gene enrichment analysis for key genes and validated them by GEO database. Gene expression differences in EBVaGC and EBVnGC cell lines was determined by quantitative real-time PCR (qRT-PCR) and western blotting and in GT38 cell and SNU719 cell which all treated by 5-Aza-CdR. Finally, the effect of key gene on the migration and proliferation capacity of EBVaGC cells was determined by Transwells assay and Cell counting Kit-8 (CCK-8) assay. We obtained a total of 687 hypermethylation-low expression genes (Hyper-LGs) and further obtained 53 DNA methylation-driver genes based on the MethylMix algorithm. A total of six key genes (SCIN, ETNK2, PCDH20, PPP1R3C, MATN2, and HOXA5) were identified by LASSO regression and Random Forest algorithm. Among them, SCIN expression was significantly lower in EBVaGC cell lines than in EBVnGC cell lines, and its expression was significantly recovered in EBVaGC cell lines treated with 5-Aza-CdR. Overexpression of SCIN can promote the proliferation and migration capacity of EBVaGC cells. Our study will provide some bioinformatics basis for the study of EBVaGC-related methylation. SCIN may be used as potential methylation biomarkers for the diagnosis and treatment of EBVaGC.

Building a Bridge Between the Mechanism of EBV Reactivation and the Treatment of EBV-Associated Cancers

Epstein-Barr virus (EBV) infection is closely associated with the development of various tumors such as lymphomas and epithelial cancers. EBV has a discrete life cycle with latency and lytic phases. In recent years, significant progress has been made in the understanding of the mechanism underlying the transition of EBV from latency to lytic replication. Multiple new lytic activation factors have been emerged and promoted our understanding of this field. In addition, we have comprehensively presented the existing therapeutic strategies and their relationship to the mechanism underlying the transition of EBV from latency to lytic replication in this review, such as lytic induction therapy and drugs to prevent EBV from entering the lytic phase fully utilize the EBV reactivation mechanisms. This year marks the 60th anniversary of the discovery of EBV, and building a bridge between the mechanism of EBV reactivation and the treatment may help us to design new approaches for treating EBV-associated diseases.

Epstein-Barr Virus-Associated Pneumonia in a Healthy Adult Presenting With Pulmonary Nodules and Deep Vein Thrombosis: A Case Report and Literature Review

Epstein-Barr virus (EBV) is a common herpesvirus that affects more than 90% of people worldwide. It is usually spread through saliva. Although most infections show no symptoms or only lead to mono, uncommon complications such as respiratory issues can arise, particularly in individuals with weakened immune systems. While rare, cases of EBV-related pneumonia, lung nodules, and venous thromboembolism have been occasionally reported. A 17-year-old male came in with fever, dyspnea, massive hemoptysis, and sore throat. Numerous pulmonary nodules were shown in imaging. According to broncho-alveolar lavage, and biopsy results EBV-induced pneumonia was diagnosed. During hospitalization, the patient also experienced deep vein thrombosis and needed heparin treatment. The current study contributes to the increasing amount of research on unusual displays of EBV in healthy adults. It highlights the significance of considering EBV in the differential diagnosis for healthy adults with unexplained pulmonary nodules and venous thromboembolism.

Precision meets repurposing: Innovative approaches in human papillomavirus and Epstein-Barr virus-driven cancer therapy

Viral malignancies represent a distinct entity among cancers. Oncoviruses like the Human Papilloma Virus (HPV) and the Epstein Barr Virus (EBV) are highly potent inducers of oncogenic transformation leading to tumor development. HPV and EBV are known to be increasingly involved in the pathogenesis of various classes of cancers like cervical, head and neck, colorectal, breast, oral and anogenitial. Therapeutic vaccines directed at such oncoviruses, often fail to unleash the desired immune response against the tumor. This is largely due to the immunosuppressive microenvironment of the virus-induced tumors. Consequently, metronomic chemotherapies administered in conjunction with therapeutic viral vaccines have considerably enhanced the antitumor activity of these vaccines. Moreover, given the unique attributes of HPV and EBV-associated cancers, therapeutic agents directly targeting the oncoproteins of these viruses are still obscure. In this light, an increasing number of reports have evidenced the repurposing of drugs for therapeutic benefits in such cancers. This work delineates the significance and implications of metronomic chemotherapy and drug repurposing in HPV and EBV-associated cancers.

Non-hepatotropic viral hepatitis: a narrative review

Non-hepatotropic viral hepatitis (NHVH) refers to acute hepatitis or acute liver failure caused by viruses that do not primarily target the liver. These viruses include the Epstein-Barr virus (EBV), cytomegalovirus (CMV), herpes simplex virus (HSV)-1 and -2, varicella zoster, parvovirus, adenovirus, adeno-associated virus type 2, measles, and severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2). The epidemiology, pathogenesis, and clinical manifestations of hepatitis due to hepatotropic viruses (hepatitis A-E) have been well studied. However, there is a paucity of data on NHVH due to its rarity, self-limiting clinical course, and vague presentation. NHVH can occur as an isolated illness or as part of a disseminated disease, and its clinical features range from self-limiting transaminitis to acute liver failure. This activity reviews the most common non-hepatotropic viruses (NHV), with a focus on their biology, etiopathogenesis, clinical manifestations, and management.

Hemophagocytic lymphohistiocytosis: current treatment advances, emerging targeted therapy and underlying mechanisms

Hemophagocytic lymphohistiocytosis (HLH) is a rapidly progressing, life-threatening syndrome characterized by excessive immune activation, often presenting as a complex cytokine storm. This hyperactive immune response can lead to multi-organ failure and systemic damage, resulting in an extremely short survival period if left untreated. Over the past decades, although HLH has garnered increasing attention from researchers, there have been few advancements in its treatment. The cytokine storm plays a crucial role in the treatment of HLH. Investigating the detailed mechanisms behind cytokine storms offers insights into targeted therapeutic approaches, potentially aiding in early intervention and improving the clinical outcome of HLH patients. To date, there is only one targeted therapy, emapalumab targeting interferon-γ, that has gained approval for primary HLH. This review aims to summarize the current treatment advances, emerging targeted therapeutics and underlying mechanisms of HLH, highlighting its newly discovered targets potentially involved in cytokine storms, which are expected to drive the development of novel treatments and offer fresh perspectives for future studies. Besides, multi-targeted combination therapy may be essential for disease control, but further trials are required to determine the optimal treatment mode for HLH.

From virus to cancer: Epstein-Barr virus miRNA connection in Burkitt's lymphoma

In Burkitt's lymphoma (BL), Epstein-Barr virus-encoded microRNAs (EBV miRNAs) are emerging as crucial regulatory agents that impact cellular and viral gene regulation. This review investigates the multifaceted functions of EBV miRNAs in the pathogenesis of Burkitt lymphoma. EBV miRNAs regulate several cellular processes that are essential for BL development, such as apoptosis, immune evasion, and cellular proliferation. These small, non-coding RNAs target both viral and host mRNAs, finely adjusting the cellular environment to favor oncogenesis. Prominent miRNAs, such as BART (BamHI-A rightward transcript) and BHRF1 (BamHI fragment H rightward open reading frame 1), are emphasized for their roles in tumor growth and immune regulation. For example, BART miRNAs prevent apoptosis by suppressing pro-apoptotic proteins, whereas BHRF1 miRNAs promote viral latency and immunological evasion. Understanding the intricate connections among EBV miRNAs and their targets illuminates BL pathogenesis and suggests novel treatment approaches. Targeting EBV miRNAs or their specific pathways offers a feasible option for developing innovative therapies that aim to disrupt the carcinogenic processes initiated by these viral components. future studies should focus on precisely mapping miRNA‒target networks and developing miRNA-based diagnostic and therapeutic tools. This comprehensive article highlights the importance of EBV miRNAs in Burkitt lymphoma, indicating their potential as biomarkers and targets for innovative treatment strategies.

Inhibiting KSHV replication by targeting the essential activities of KSHV processivity protein, PF-8

Kaposi's Sarcoma Herpesvirus (KSHV) is the causative agent of several human diseases. There are no cures for KSHV infection. KSHV establishes biphasic lifelong infections. During the lytic phase, new genomes are replicated by seven viral DNA replication proteins. The processivity factor's (PF-8) functions to tether DNA polymerase to DNA, so new viral genomes are efficiently synthesized. PF-8 self-associates, interacts with KSHV DNA replication proteins and the viral DNA. Inhibition of viral DNA replication would diminish the infection within a host and reduce transmission to new individuals. In this review we summarize PF-8 molecular and structural studies, detail the essential protein-protein and nucleic acid interactions needed for efficient lytic DNA replication, identify future areas for investigation and propose PF-8 as a promising antiviral target. Additionally, we discuss similarities that the processivity factor from Epstein-Barr virus shares with PF-8, which could promote a pan-herpesvirus antiviral therapeutic targeting strategy.

Stearoyl-CoA desaturase 1 is targeted by EBV-encoded miR-BART20-5p and regulates cell autophagy, proliferation, and migration in EBV-associated gastric cancer

Epstein-Barr virus (EBV) is the first human oncogenic virus known to express microRNAs (miRNAs), which are closely associated with the development of various tumors, including nasopharyngeal and gastric cancers. Stearoyl-CoA Desaturase 1 (SCD1) is a key enzyme in fatty acid synthesis, highly expressed in numerous tumors, promoting tumor growth and metastasis, making it a potential therapeutic target. In this study, we found that SCD1 expression in EBV-associated gastric cancer (EBVaGC) was significantly lower than in EBV-negative gastric cancer (EBVnGC) at both cellular and tissue levels. In addition, EBV-miR-BART20-5p targets the 3'-UTR of SCD1, downregulating its expression. Moreover, overexpression of SCD1 in EBVaGC cells promoted cell migration and proliferation while inhibiting autophagy. These results suggest that EBV-encoded miRNA-BART20-5p may contribute to EBVaGC progression by targeting SCD1.

A small molecule that selectively inhibits the growth of Epstein-Barr virus-latently infected cancer cells

Epstein-Barr virus (EBV), an oncogenic herpesvirus, is predominantly found in the latent infection form and is highly associated with many human malignancies, which mainly have poor prognoses and no effective treatments. Here, we obtained thirteen compounds from small-molecule libraries for specific inhibition of EBV-latently infected cell growth in vitro by high-throughput screening. Among them, cetrimonium bromide (CetB) was identified to selectively inhibit the growth of different EBV-infected B lymphoma cell lines. Importantly, CetB reduced EBNA1 protein stability, activated G1 arrest and early apoptosis of EBV-latently infected cells without viral lytic reactivation, which leads to dramatically inhibit colony formation and tumor growth of EBV-infected cells in vitro and in vivo, and significantly prolong the survival of tumor-bearing mice. Overall, these findings demonstrate that CetB acts as a highly selective inhibitor of the growth of EBV-infected cells and has the potential for further development of effective therapeutic strategies specific against EBV-associated cancers.

Combination therapy synergism prediction for virus treatment using machine learning models

Combining different drugs synergistically is an essential aspect of developing effective treatments. Although there is a plethora of research on computational prediction for new combination therapies, there is limited to no research on combination therapies in the treatment of viral diseases. This paper proposes AI-based models for predicting novel antiviral combinations to treat virus diseases synergistically. To do this, we assembled a comprehensive dataset comprising information on viral strains, drug compounds, and their known interactions. As far as we know, this is the first dataset and learning model on combination therapy for viruses. Our proposal includes using a random forest model, an SVM model, and a deep model to train viral combination therapy. The machine learning models showed the highest performance, and the predicted values were validated by a t-test, indicating the effectiveness of the proposed methods. One of the predicted combinations of acyclovir and ribavirin has been experimentally confirmed to have a synergistic antiviral effect against herpes simplex type-1 virus, as described in the literature.

Mechanistic Understanding of EBV+Lymphoproliferative Disease Development After Transplantation

Posttransplant lymphoproliferative disorders (PTLDs) are among the most common malignant complications after transplantation, leading to a drastic reduction in patient survival rates. The majority of PTLDs are tightly linked to Epstein-Barr virus (EBV+PTLDs) and are the result of an uncontrolled proliferation of EBV-infected cells. However, although EBV infections are a common finding in transplant recipients, most patients with high EBV loads will never develop EBV+PTLD. Natural killer cells and EBV-specific CD8+ T lymphocytes are critical for controlling EBV-infected cells, and the impairment of these cytotoxic immune responses facilitates the unfettered proliferation of EBV-infected cells. Recent years have seen a considerable increase in available literature aiming to describe novel risk factors associated with the development of EBV+PTLD, which may critically relate to the strength of EBV-specific natural killer cell and EBV-CD8+ T lymphocyte responses. The accumulation of risk factors and the increased risk of developing EBV+PTLD go hand in hand. On the one hand, most of these risk factors, such as the level of immunosuppression or the EBV donor and recipient serologic mismatch, and distinct genetic risk factors are host related and affect cytotoxic EBV-specific immune responses. On the other hand, there is growing evidence that distinct EBV variants may have an increased malignant potential and are thus more likely to induce EBV+PTLD. Here, we aim to review, from a mechanistic point of view, the risk factors for EBV+PTLD in the host and the infecting EBV variants that may explain why only a minority of transplant recipients develop EBV+PTLD.

Effects of ganciclovir combined with recombinant human interferon-α on clinical efficacy and immune function in children with infectious mononucleosis

Objective

To evaluate the effects of ganciclovir combined with recombinant human interferon on clinical efficacy and immune function of children with infectious mononucleosis(IM).

Methods

This was a retrospective study. Children (n=120) with IM hospitalized in Beijing Children's Hospital Affiliated to Capital Medical University Baoding Hospital from January 2020 to January 2022 were selected and randomly divided into study group and control group((n=60). Patients in the control group were treated with ganciclovir by intravenous infusion, and patients in the study group were given ganciclovir+recombinant human interferon-α1b. The time for eliminating clinical symptoms, the levels of inflammatory cytokines, immune function condition and T-lymphocyte subsets between the two groups were compared and analyzed.

Results

After treatment, the time for body temperature returned to normal, time for recovery from cervical lymphadenopathy, time for recovery from hepatosplenomegaly and time for disappearance of angina and oral mucosal congestion in the study group were significantly shorter than those in the control group(p= 0.00); after treatment, the levels of TNF-a and IL-6 in the study group were significantly lower than those in the control group; the indexes of CD3+ and CD8+ in the study group were significantly lower than those in the control group; after treatment, the levels of CD4+ and CD4+/CD8+ in the study group were significantly higher than those in the control group.

Conclusion

Ranciclovir combined with recombinant human interferon-α1b, rapid improvements of clinical symptoms, significantly decreased inflammatory cytokines, improved T-lymphocyte function and no significant increase in adverse drug reactions were found in children with IM.

Treatment of Epstein-Barr Virus infection in immunocompromised patients

Epstein-Barr Virus (EBV), is a ubiquitous γ-Herpesvirus that infects over 95% of the human population and can establish a life-long infection without causing any clinical symptoms in healthy individuals by residing in memory B-cells. Primary infection occurs in childhood and is mostly asymptomatic, however in some young adults it can result in infectious mononucleosis (IM). In immunocompromised individuals however, EBV infection has been associated with many different malignancies. Since EBV can infect both epithelial and B-cells and very rarely NK cells and T-cells, it is associated with both epithelial cancers like nasopharyngeal carcinoma (NPC) and gastric carcinoma (GC), with lymphomas including Burkitt Lymphoma (BL) or Post-transplant Lymphoproliferative Disorder (PTLD) and rarely with NK/T-cell lymphomas. Currently there are no approved antivirals active in PTLD nor in any other malignancy. Moreover, lytic phase disease almost never requires antiviral treatment. Although many novel therapies against EBV have been described, the management and/or prevention of EBV primary infections or reactivations remains difficult. In this review, we discuss EBV infection, therapies targeting EBV in both lytic and latent state with novel therapeutics developed that show anti-EBV activity as well as EBV-associated malignancies both, epithelial and lymphoproliferative malignancies and emerging therapies targeting the EBV-infected cells.

Acyclovir as a Novel Treatment for Severe Chronic Active Epstein-Barr Virus

Epstein-Barr virus (EBV) is a widely infectious pathogen affecting most of the global population at some point in their life. While, typically, primary infections are subclinical, chronic persistence of the virus due to T-cell proliferation can cause severe complications. Acute hepatitis due to chronic active EBV (CAEBV) has rarely been documented. This case details a previously healthy 81-year-old woman who presented with complaints of diffuse abdominal pain, nausea, and vomiting. Her diagnostic workup demonstrated an EBV infection with worsening thrombocytopenia, transaminitis, and hepatocellular liver injury with acute ascites. Her hospitalization was resistant to the traditional supportive treatment of EBV, requiring intensive care management and unorthodox therapy. Although antivirals have demonstrated limited utility in the treatment of CAEBV, the severity of her illness and refractory hospital course necessitated the use of acyclovir. She made a complete recovery with no deficits. The case demonstrates the presentation of acute hepatitis and ascites as a result of CAEBV, the clinical sequelae, and acyclovir as a potential new treatment option.

The Gut Connection: Exploring the Possibility of Implementing Gut Microbial Metabolites in Lymphoma Treatment

Recent research has implicated the gut microbiota in the development of lymphoma. Dysbiosis of the gut microbial community can disrupt the production of gut microbial metabolites, thereby impacting host physiology and potentially contributing to lymphoma. Dysbiosis-driven release of gut microbial metabolites such as lipopolysaccharides can promote chronic inflammation, potentially elevating the risk of lymphoma. In contrast, gut microbial metabolites, such as short-chain fatty acids, have shown promise in preclinical studies by promoting regulatory T-cell function, suppressing inflammation, and potentially preventing lymphoma. Another metabolite, urolithin A, exhibited immunomodulatory and antiproliferative properties against lymphoma cell lines in vitro. While research on the role of gut microbial metabolites in lymphoma is limited, this article emphasizes the need to comprehend their significance, including therapeutic applications, molecular mechanisms of action, and interactions with standard chemotherapies. The article also suggests promising directions for future research in this emerging field of connection between lymphoma and gut microbiome.

Insights into the interplay between Epstein-Barr virus (EBV) and multiple sclerosis (MS): A state-of-the-art review and implications for vaccine development

Background and Aims

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS). MS results from an inflammatory process leading to the loss of neural tissue and increased disability over time. The role of Epstein Barr Virus (EBV), as one of the most common global viruses, in MS development has been the subject of several studies. However, many related questions are still unanswered. This study aimed to review the connection between MS and EBV and provide a quick outline of MS prevention using EBV vaccination.

Methods

For this narrative review, an extensive literature search using specific terms was conducted across online databases, including PubMed/Medline, Scopus, Web of Science, and Google Scholar, to identify pertinent studies.

Results

Several studies proved that almost 100% of people with MS showed a history of EBV infection, and there was an association between high titers of EBV antibodies and an increased risk of MS development. Various hypotheses are proposed for how EBV may contribute to MS directly and indirectly: (1) Molecular Mimicry, (2) Mistaken Self, (3) Bystander Damage, and (4) Autoreactive B cells infected with EBV.

Conclusion

Given the infectious nature of EBV and its ability to elude the immune system, EBV emerges as a strong candidate for being the underlying cause of MS. The development of an EBV vaccine holds promise for preventing MS; however, overcoming the challenge of creating a safe and efficacious vaccine presents a significant obstacle.

Prevention of Oncogenic Gammaherpesvirinae (EBV and HHV8) Associated Disease in Solid Organ Transplant Recipients

Long-term risk for malignancy is higher among solid organ transplant (SOT) recipients compared to the general population. Four non-hepatitis viruses have been recognized as oncogenic in SOT recipients-EBV, cause of EBV-associated lymphoproliferative diseases; human herpes virus 8 (HHV8), cause of Kaposi sarcoma, primary effusion lymphoma and multicentric Castleman disease; human papilloma virus, cause of squamous cell skin cancers, and Merkel cell polyomavirus, cause of Merkel cell carcinoma. Two of these viruses (EBV and HHV8) belong to the human herpes virus family. In this review, we will discuss key aspects regarding the clinical presentation, diagnosis, treatment, and prevention of diseases in SOT recipients associated with the two herpesviruses.

Adult's Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis: A case report

Adult's Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis is a rare and life-threatening condition characterized by atypical initial symptoms and rapid disease progression. To facilitate early diagnosis and prompt treatment, it is imperative to implement early multidisciplinary intervention and prioritize pathogen detection, as these measures significantly contribute to enhancing patient prognosis.

Epstein-Barr virus infection: the micro and macro worlds

Epstein‒Barr virus (EBV) is a DNA virus that belongs to the human B lymphotropic herpesvirus family and is highly prevalent in the human population. Once infected, a host can experience latent infection because EBV evades the immune system, leading to hosts harboring the virus for their lifetime. EBV is associated with many diseases and causes significant challenges to human health. This review first offers a description of the natural history of EBV infection, clarifies the interaction between EBV and the immune system, and finally focuses on several major types of diseases caused by EBV infection.

Epstein-Barr virus infection leading to multiorgan involvement in an immunocompetent man

Epstein-Barr virus (EBV) is a commonly asymptomatic widespread human herpes virus affecting over 90% of the population. It mostly originates complications like simple sore throat and infectious mononucleosis but severe manifestations are rare. Herein we report a 30-year-old immunocompetent man who presented with fever, sore throat, general weakness, and drowsiness. The diagnosis was formulated based on the positive RT-PCR test for EBV DNA and serological detection of IgM antibody against viral capsid antigen. The patient developed severe meningoencephalitis, myocarditis, and bowel perforation and passed away after 72 days of hospitalization.

Therapeutic effect of intravenous acyclovir in children with infectious mononucleosis and immune function

OBJECTIVE

To explore the application value of intravenous acyclovir in children with infectious mononucleosis (IM) and its effects on immune function.

METHODS

The data of 136 children with IM treated in Anhui Provincial Children's Hospital from March 2019 to March 2022 were retrospectively analyzed. According to the inclusion and exclusion criteria, 98 children were selected. Among them, 45 children treated with routine ribavirin were assigned to the control group, and the other 53 children treated with intravenous acyclovir were enrolled into the observation group. The two groups were compared in terms of efficacy, incidence of adverse reactions, recovery time of clinical symptoms, and immune function indexes, IgG, IgA, IgM, white blood cell (WBC) count and lymphocyte proportion, before and 10 days after the treatment. Independent risk factors affecting efficacy were analyzed by multivariate logistic regression analysis.

RESULTS

The observation group showed a significantly higher overall response rate than the control group (P=0.025). The control group experienced significantly longer recovery time of body temperature returning to normal, cure time of isthmitis, time for lymph node reduction, and alleviation time of hepatomegaly than the observation group (P<0.05). Additionally, the control group presented with a significantly higher incidence of adverse reactions than the observation group (P=0.028). After treatment, the observation group showed significantly lower levels of IgG, IgA, IgM, WBC count and lymphocyte proportion than the control group (all P<0.010). Longer average course of disease (OR: 1.449, 95% CI: 1.095-1.918), higher admission temperature (OR: 6.996, 95% CI: 1.350-36.257), higher admission IgA level (OR: 4.735, 95% CI: 1.357-16.520) and higher admission IgG level (OR: 1.470, 95% CI: 1.012-2.134) were independent risk factors for ineffective efficacy, while acyclovir (OR: 0.058, 95% CI: 0.005-0.729) was an independent protective factor.

CONCLUSION

In the treatment of IM, intravenous acyclovir can substantially improve the overall clinical response rate for patients, with less adverse reactions, and can greatly alleviate various clinical symptoms and signs including fever, isthmitis, cervical lymph node enlargement, and hepatosplenomegaly, with obvious regulating effects on the immune function, so it is worth popularizing and applying in clinical practice.

Recent Updates on Viral Oncogenesis: Available Preventive and Therapeutic Entities

Human viral oncogenesis is a complex phenomenon and a major contributor to the global cancer burden. Several recent findings revealed cellular and molecular pathways that promote the development and initiation of malignancy when viruses cause an infection. Even, antiviral treatment has become an approach to eliminate the viral infections and prevent the activation of oncogenesis. Therefore, for a better understanding, the molecular pathogenesis of various oncogenic viruses like, hepatitis virus, human immunodeficiency viral (HIV), human papillomavirus (HPV), herpes simplex virus (HSV), and Epstein-Barr virus (EBV), could be explored, especially, to expand many potent antivirals that may escalate the apoptosis of infected malignant cells while sparing normal and healthy ones. Moreover, contemporary therapies, such as engineered antibodies antiviral agents targeting signaling pathways and cell biomarkers, could inhibit viral oncogenesis. This review elaborates the recent advancements in both natural and synthetic antivirals to control viral oncogenesis. The study also highlights the challenges and future perspectives of using antivirals in viral oncogenesis.

Gastrointestinal tract and viral pathogens

Viral gastroenteritis is the most common viral illness that affects the gastrointestinal (GI) tract, causing inflammation and irritation of the lining of the stomach and intestines. Common signs and symptoms associated with this condition include abdominal pain, diarrhea, and dehydration. The infections commonly involved in viral gastroenteritis are rotavirus, norovirus, and adenovirus, which spread through the fecal-oral and contact routes and cause non-bloody diarrhea. These infections can affect both immunocompetent and immunocompromised individuals. Since the pandemic in 2019, coronavirus gastroenteritis has increased in incidence and prevalence. Morbidity and mortality rates from viral gastroenteritis have declined significantly over the years due to early recognition, treatment with oral rehydration salts, and prompt vaccination. Improved sanitation measures have also played a key role in reducing the transmission of infection. In addition to viral hepatitis causing liver disease, herpes virus, and cytomegalovirus are responsible for ulcerative GI disease. They are associated with bloody diarrhea and commonly occur in im-munocompromised individuals. Hepatitis viruses, Epstein-Barr virus, herpesvirus 8, and human papillomavirus have been involved in benign and malignant diseases. This mini review aims to list different viruses affecting the GI tract. It will cover common symptoms aiding in diagnosis and various important aspects of each viral infection that can aid diagnosis and management. This will help primary care physicians and hospitalists diagnose and treat patients more easily.

The interaction between Epstein-Barr virus and multiple sclerosis genetic risk loci: insights into disease pathogenesis and therapeutic opportunities

Multiple sclerosis (MS) is a chronic neurodegenerative autoimmune disease, characterised by the demyelination of neurons in the central nervous system. Whilst it is unclear what precisely leads to MS, it is believed that genetic predisposition combined with environmental factors plays a pivotal role. It is estimated that close to half the disease risk is determined by genetic factors. However, the risk of developing MS cannot be attributed to genetic factors alone, and environmental factors are likely to play a significant role by themselves or in concert with host genetics. Epstein-Barr virus (EBV) infection is the strongest known environmental risk factor for MS. There has been increasing evidence that leaves little doubt that EBV is necessary, but not sufficient, for developing MS. One plausible explanation is EBV may alter the host immune response in the presence of MS risk alleles and this contributes to the pathogenesis of MS. In this review, we discuss recent findings regarding how EBV infection may contribute to MS pathogenesis via interactions with genetic risk loci and discuss possible therapeutic interventions.

Epstein-Barr virus as a cause of multiple sclerosis: opportunities for prevention and therapy

Multiple sclerosis is a chronic inflammatory disease of the CNS that results from the interplay between heritable and environmental factors. Mounting evidence from different fields of research supports the pivotal role of the Epstein-Barr virus (EBV) in the development of multiple sclerosis. However, translating this knowledge into clinically actionable information requires a better understanding of the mechanisms linking EBV to pathophysiology. Ongoing research is trying to clarify whether EBV causes neuroinflammation via autoimmunity or antiviral immunity, and if the interaction of EBV with genetic susceptibility to multiple sclerosis can explain why a ubiquitous virus promotes immune dysfunction in susceptible individuals. If EBV also has a role in driving disease activity, the characterisation of this role will help diagnosis, prognosis, and treatment in people with multiple sclerosis. Ongoing clinical trials targeting EBV and new anti-EBV vaccines provide hope for future treatments and preventive interventions.

Integration of Human and Viral miRNAs in Epstein-Barr Virus-Associated Tumors and Implications for Drug Repurposing

Epstein-Barr virus (EBV) is associated with several tumors, and has substantial relevance for public health. Therapeutics innovation for EBV-related disorders is much needed. In this context, miRNAs are noncoding RNA molecules that play vital roles in EBV infection. miRNA-Seq and RNA-Seq data for EBV-associated clinical samples and cell lines have been generated, but their detailed integrative analyses, and exploitation for drug repurposing against EBV are lacking. Hence, we identified and analyzed the differentially expressed miRNAs (DEmiRs) in EBV-infected cell lines (28) and infected (28) and uninfected human tissue (20) samples using an in-house pipeline. We found significantly enriched host miRNAs like hsa-mir-3651, hsa-mir-1248, and hsa-mir-29c-3p in EBV-infected samples from EBV-associated nasopharyngeal carcinoma and Hodgkin's lymphoma, among others. Furthermore, we also identified significantly enriched novel miRNAs such as hsa-mir-29c-3p, hsa-mir-3651, and hsa-mir-98-3p, which were not previously reported in EBV-related tumors. Differentially expressed mRNAs (DEMs) were identified in EBV-infected cell lines (21) and uninfected human tissue (14) samples. We predicted and selected 1572 DEMs (upregulated) that are targeted by 547 DEmiRs (downregulated). These were further classified into essential (870) and nonessential (702) genes. Moreover, a miRNA-mRNA network was developed for the hub miRNAs. Importantly, we used the DEMs during EBV latent infection types I, II, and III to identify the candidate drugs for repurposing: Glyburide, Levodopa, Nateglinide, and Stiripentol, among others. To the best of our knowledge, this is the first integrative analyses that identified DEmiRs and DEMs as potential therapeutic targets and predicted drugs as potential candidates for repurposing against EBV-related tumors.

EBV infection mediated BDNF expression is associated with bladder inflammation in interstitial cystitis/bladder pain syndrome with Hunner's lesion

Interstitial cystitis/bladder pain syndrome with Hunner's lesion (HIC) is characterized by chronic inflammation and nerve hyperplasia; however, the pathogenesis of HIC remains a mystery. In this study, we detected both Epstein-Barr virus (EBV) latency infection genes EBNA-1 and LMP-1 and EBV lytic infection BZLF-1 and BRLF-1 expression in the HIC bladders, indicating the coexistence of EBV persistence and reactivation in the B cells in HIC bladders. Upregulation of EBV-associated inflammatory genes in HIC bladders, such as TNF-α and IL-6, suggests EBV infection is implicated in the pathogenesis of bladder inflammation. Nerve hyperplasia and upregulation of brain-derived neurotrophic factor (BDNF) were noted in the HIC bladders. Double immunochemical staining and flow cytometry revealed the origin of BDNF to be EBV-infected B cells. Inducible BDNF expression was noted in B cells upon EBV infection, but not in the T cells. A chromatin immunoprecipitation study revealed BDNF transcription could be promoted by cooperation between EBV nuclear antigens, chromatin modifiers, and B-cell-specific transcription. Knockdown of BDNF in EBV-infected B cells resulted in the inhibition of cell proliferation and viability. Downregulation of phosphorylated SMAD2 and STAT3 after BDNF knockdown may play a role in the mechanism. Implantation of latent EBV-infected B cells into rat bladder walls resulted in a higher expression level of CD45 and PGP9.5, suggesting tissue inflammation and nerve hyperplasia. In contrast, implantation of BDNF depleted EBV-infected B cells abrogated these effects. This is the first study to provide insights into the mechanisms underlying the involvement of EBV-infected B cells in HIC pathogenesis. © 2022 The Pathological Society of Great Britain and Ireland.

An Acute Presentation of Epstein-Barr Virus (EBV) Infection in an Immunocompromised Gentleman

Epstein-Barr virus (EBV) is a relevant cause of many clinical manifestations with a range of malignant and non-malignant presentations. This is particularly important to consider in immunosuppressed individuals. We present a case of a 36-year-old individual with ulcerative colitis who was in remission whilst taking mercaptopurine. The patient presented with weight loss, night sweats, and significant laboratory serum abnormalities on monitoring. Relevant investigations into his presentation ruled out a malignant feature, but his serology confirmed infection with EBV with the spread of infection to the liver and bone marrow. Overall, we identify a notable yet relevant clinical expression of EBV infection in the context of an immunosuppressed individual.

Epstein-Barr virus: Biology and clinical disease

Epstein-Barr virus (EBV) is a ubiquitous, oncogenic virus that is associated with a number of different human malignancies as well as autoimmune disorders. The expression of EBV viral proteins and non-coding RNAs contribute to EBV-mediated disease pathologies. The virus establishes life-long latency in the human host and is adept at evading host innate and adaptive immune responses. In this review, we discuss the life cycle of EBV, the various functions of EBV-encoded proteins and RNAs, the ability of the virus to activate and evade immune responses, as well as the neoplastic and autoimmune diseases that are associated with EBV infection in the human population.

Epstein-Barr Virus Detection in the Central Nervous System of HIV-Infected Patients

Simply detecting Epstein-Barr virus deoxyribonucleic acid (EBV-DNA) is insufficient to diagnose EBV-associated diseases. The current literature around EBV-DNA detection from cerebrospinal fluid (CSF) in human immunodeficiency virus (HIV)-positive non-lymphoma patients was systematically reviewed and a meta-analysis reporting the estimated pooled prevalence in this population when PCR methods are employed, targeting different sequence segments within the EBV genome, was conducted. Using a combination of three key concepts-Epstein-Barr virus detection, central nervous system disease, and human cerebrospinal fluid-and their MeSH terms, the PubMed database was searched. A total of 273 papers reporting the detection of EBV in CNS were screened, of which 13 met the inclusion criteria. The meta-analysis revealed a pooled prevalence of EBV-DNA in CSF of 20% (CI: 12-31%). The highest pooled prevalence was from studies conducted on the African population at 39% (CI: 27-51%). The investigation of the presence of EBV-DNA in the CSF was also very varied, with several gene targets used. While most patients from the articles included in this review and meta-analysis were symptomatic of CNS disorders, the pathogenicity of EBV in non-lymphoma HIV patients when detected in CSF has still not been determined. The presence of EBV-DNA in the CNS remains a concern, and further research is warranted to understand its significance in causing CNS disorders.

Case report: Cellular therapy for hydroa vacciniforme-like lymphoproliferative disorder in pediatric common variable immunodeficiency with chronic active Epstein-Barr virus infection

Hydroa vacciniforme-like lymphoproliferative disorder (HV-LPD) is a cutaneous form of chronic active Epstein-Barrvirus (EBV) infection, which can develop into the extremely rare systemic lymphoma. Patients with Inborn errors of immunity (IEI), such as common variable immunodeficiency (CVID), are at higher risk of developing a severe course of infections especially viral and malignancies than the general population. The aim of the study was to present complex diagnostic and therapeutic management of HV-LPD. The clinical diagnosis was confirmed at the histological and molecular level with next generation sequencing. HV-LPD was diagnosed in a patient with CVID and chronic active Epstein–Barr virus (CAEBV) infection. The patient was refractory to CHOP chemotherapy and immunosuppressive treatment in combination with antiviral drugs (prednisone, bortezomib, gancyclovir). The third-party donor EBV-specific cytotoxic T cells (EBV-CTL, tabelecleucel) were used, which stabilised the disease course. Finally, matched unrelated donor hematopoietic cell transplantation (MUD-HCT) was performed followed by another cycle of EBV-CTL.

Neurology of Acute Viral Infections

As specialists in acute neurology, neurohospitalists are often called upon to diagnose and manage acute viral infections affecting the nervous system. In this broad review covering the neurology of several acute viral infections, our aim is to provide key diagnostic and therapeutic pearls of practical use to the busy neurohospitalist. We will review acute presentations, diagnosis, and treatment of human herpesviruses, arboviruses, enteroviruses, and some vaccine-preventable viruses. The neurological effects of coronaviruses, including COVID-19, are not covered in this review.

Recurrence of infectious mononucleosis in adults after remission for 3 years: A case report

BACKGROUND

Infectious mononucleosis (IM) is a disease caused by Epstein–Barr virus (EBV). EBV infection is common in children; however, it can cause IM in adults. Studies on recurrence of IM in adults after remission are limited.

CASE SUMMARY

We report a 28-year-old man who presented with IM-like symptoms with mild liver damage after initial remission of IM for 3 years. He was first diagnosed with IM and treated in 2015. Follow-up tests in 2016 and 2017 did not show any abnormalities. In November 2018, he presented with swelling of the tonsils. He was misdiagnosed with acute suppurative tonsillitis and treated for 5 d. No signs of improvement were observed. He was readmitted with recurrent fever, pharyngalgia, fatigue, and systemic muscle pain. Examinations revealed enlargement of the tonsils and cervical lymph nodes. Blood tests revealed elevated transaminase levels. Anti-EBV test was positive, indicating virus reactivation. IM recurrence was confirmed on the basis of laboratory tests and clinical manifestations. He was treated with antiviral, anti-infective, and hepatoprotective drugs and vitamin supplements. His condition improved and no abnormalities were observed during follow-up.

CONCLUSION

Recurrence of IM after remission is possible in adults; therefore, long-term follow-up and monitoring are essential.

[Infectious mononucleosis in practice of otorhinolaryngologist]

Infectious mononucleosis (IM) is an acute viral infection that usually occurs with fever, acute tonsillitis, affects lymph nodes, liver, spleen, and with specific changes in the hemogram. One of the most frequent symptoms of the disease is sore throat which leads people to otorhinolaryngologist. Several pathogens may be the cause of IM, but Epstein-Barr virus(EBV) plays a key role. EBV is a γ-herpes virus and about 90% of world`s population is infected with this one. Severe IM can lead to potential life-threating conditions, for example upper airway obstruction, spleen rupture. In addition to acute IM, EBV-infection can lead to a number of neoplastic and autoimmune diseases. Due to the non-specificity of IM symptoms and the emerging difficulties in laboratory and serological diagnosis of this disease, the problem of timely diagnosis and treatment in this category of patients remains very relevant.

Immunocompromised Patients with Therapy-Refractory Chronic Skin Diseases Show Reactivation of Latent Epstein‒Barr Virus and Cytomegalovirus Infection

Reactivation of latent Epstein‒Barr virus (EBV) and/or Cytomegalovirus (CMV) infection is a dreaded complication in immunocompromised patients receiving hematopoietic stem cell transplantation. Evidence is sparse on whether subclinical reactivation of viral infection may also be of clinical relevance in dermatological patients. We screened patients (N = 206) suffering from chronic skin diseases for subclinical reactivation of EBV and CMV infection. We found that immunocompromised patients with therapy-refractory chronic skin diseases showed higher rates of subclinical reactivation of CMV and EBV infection (6.7% vs. 0% for EBV and 16.7% vs. 5.6% for CMV) and a higher prevalence of virus-specific DNA in skin tissue (30.8% vs. 0% for EBV and 21.4% vs. 0% for CMV) than nonimmunocompromised patients with chronic skin diseases. T cells isolated from lesional skin exhibited up to 14-fold increased proliferation with production of T helper type 1 and T helper type 17 cytokines on stimulation with viral proteins, providing evidence for possible aggravation of the underlying skin diseases by viral infection. Improvement of skin lesions in patients with reactivation of CMV infection (n = 4) was observed on antiviral treatment. Our data suggest that subclinical reactivation of EBV and/or CMV infection is an under-recognized condition in the dermatological patient population with chronic skin diseases.

Clinical characteristics and effectiveness of antiviral agents in hospitalized children with infectious mononucleosis in China: A multicenter retrospective study

IMPORTANCE

The clinical characteristics of infectious mononucleosis (IM) in Chinese children have not been evaluated in multicenter studies, and the effectiveness of antiviral treatment are controversial.

OBJECTIVE

To investigate the clinical characteristics of Chinese children with IM and current status of antiviral therapy for affected patients.

METHODS

Hospitalized patients with IM were enrolled between 2018 and 2020 in five children's hospitals in China. The clinical characteristics were compared among four age groups: <3 years, 3-<6 years, 6-<10 years, and ≥10 years. The clinical characteristics of IM and effectiveness of antiviral therapy were compared among patients receiving acyclovir (ACV), ganciclovir (GCV), and no antiviral therapy (i.e., non-antiviral group).

RESULTS

In total, 499 patients were analyzed; most patients were 3-<6 years of age. The most common symptoms and signs included fever (100%), lymphadenopathy (98.6%), pharyngitis (86.4%), eyelid edema (76.8%), and snoring (72.9%). There were significant differences in rash, hepatomegaly, and liver dysfunction among the four age groups. Patients aged < 3 years had a lower incidence of liver dysfunction and a higher incidence of rash. Among the 499 patients, 50.1% were treated with GCV, 26.3% were treated with ACV, and 23.6% received no antiviral therapy. Compared with the non-antiviral group, patients in the ACV and GCV groups had longer durations of fever (P < 0.001). There were no significant differences in the incidences of complications among the three treatment groups.

INTERPRETATION

The incidence of IM in Chinese children peaked at 3-<6 years of age. Clinical features of IM varied according to age. Patients receiving antiviral therapy exhibited more serious clinical manifestations than did patients without antiviral therapy. The effectiveness of antiviral therapy for IM requires further analysis.

Reviewing Antiviral Research Against Viruses Causing Human Diseases - A Structure Guided Approach

The littlest of all the pathogens, viruses have continuously been the foremost strange microorganisms to consider. Viral Infections can cause extreme sicknesses as archived by the HIV/AIDS widespread or the later Ebola or Zika episodes. Apprehensive framework distortions are too regularly watched results of numerous viral contaminations. Besides, numerous infections are oncoviruses, which can trigger different sorts of cancer. Nearly every year a modern infection species rises debilitating the world populace with an annihilating episode. Subsequently, the need of creating antivirals to combat such rising infections. In any case, from the innovation of to begin with antiviral medicate Idoxuridine in 1962 to the revelation of Baloxavir marboxil (Xofluza) that was FDA-approved in 2018, the hone of creating antivirals has changed significantly. In this article, different auxiliary science strategies have been described that can be referral for therapeutics innovation.

Association between Antiviral Prophylaxis and Cytomegalovirus and Epstein-Barr Virus DNAemia in Pediatric Recipients of Allogeneic Hematopoietic Stem Cell Transplant

Background: Epstein–Barr virus (EBV) and cytomegalovirus (CMV) infections can have serious consequences during the period of aplasia and lymphopenia following hematopoietic stem cell transplantation (HSCT). Large pediatric cohort studies examining the effect of antiviral prophylaxis against these viruses are scarce. The present study aimed to analyse the potential effect of antiviral prophylaxis (acyclovir and famciclovir) on active post-transplant EBV and CMV infection in a pediatric cohort of allogeneic HSCT recipients. Methods: We used data from the TREASuRE cohort, consisting of 156 patients who had a first allogeneic HSCT, enrolled in four pediatric centers in Canada between July 2013 and March 2017. Follow-up was performed from the time of transplant up to 100 days post-transplant. Adjusted hazard ratio (HR) with 95% confidence intervals (CI) for the association between antiviral prophylaxis with acyclovir and/or famciclovir and EBV and CMV DNAemia was estimated using multivariate Cox regression models. Results: The post-transplant cumulative incidence of EBV and CMV DNAemia at 100 days of follow-up were, respectively, 34.5% (95% CI: 27.6–42.6) and 19.9% (95% CI: 14.5–27.1). For acyclovir, the adjusted hazard ratio (HR) for CMV and EBV DNAemia was 0.55 (95% CI: 0.24–1.26) and 1.41 (95% CI: 0.63–3.14), respectively. For famciclovir, the adjusted HR were 0.82 (95% CI: 0.30–2.29) and 0.79 (95% CI: 0.36–1.72) for CMV and EBV DNAemia, respectively. Conclusion: The antivirals famciclovir and acyclovir did not reduce the risk of post-transplant CMV and EBV DNAemia among HSCT recipients in our pediatric population.

An MHV-68 Mutator Phenotype Mutant Virus, Confirmed by CRISPR/Cas9-Mediated Gene Editing of the Viral DNA Polymerase Gene, Shows Reduced Viral Fitness

Drug resistance studies on human γ-herpesviruses are hampered by the absence of an in vitro system that allows efficient lytic viral replication. Therefore, we employed murine γ-herpesvirus-68 (MHV-68) that efficiently replicates in vitro as a model to study the antiviral resistance of γ-herpesviruses. In this study, we investigated the mechanism of resistance to nucleoside (ganciclovir (GCV)), nucleotide (cidofovir (CDV), HPMP-5azaC, HPMPO-DAPy) and pyrophosphate (foscarnet (PFA)) analogues and the impact of these drug resistance mutations on viral fitness. Viral fitness was determined by dual infection competition assays, where MHV-68 drug-resistant viral clones competed with the wild-type virus in the absence and presence of antivirals. Using next-generation sequencing, the composition of the viral populations was determined at the time of infection and after 5 days of growth. Antiviral drug resistance selection resulted in clones harboring mutations in the viral DNA polymerase (DP), denoted Y383S^GCV, Q827R^HPMP-5azaC, G302W^PFA, K442T^PFA, G302W+K442T^PFA, C297W^HPMPO-DAPy and C981Y^CDV. Without antiviral pressure, viral clones Q827R^HPMP-5azaC, G302W^PFA, K442T^PFA and G302W+K442T^PFA grew equal to the wild-type virus. However, in the presence of antivirals, these mutants had a growth advantage over the wild-type virus that was moderately to very strongly correlated with antiviral resistance. The Y383S^GCV mutant was more fit than the wild-type virus with and without antivirals, except in the presence of brivudin. The C297W and C981Y changes were associated with a mutator phenotype and had a severely impaired viral fitness in the absence and presence of antivirals. The mutator phenotype caused by C297W in MHV-68 DP was validated by using a CRISPR/Cas9 genome editing approach.

Death of unknown cause? Post-mortem diagnosis of fulminant course of an EBV-associated secondary hemophagocytic lymphohistiocytosis

HLH is a life-threatening disease, which is characterized by a dysregulated immune response with uncontrolled T cell and macrophage activation. The often fulminant course of the disease needs a fast diagnostic work-up to initiate as soon as possible the appropriate therapy. We present herein the case of a 71-year-old patient with rapidly progressive hyperinflammatory syndrome, which post mortem resulted in the diagnosis of EBV-associated HLH. With this case report, we intend to highlight the relevance of the HScore in the diagnosis of HLH, to create a greater awareness for EBV as a trigger of HLH, and to demonstrate the importance of treating EBV-associated HLH as early as possible.

Sildenafil prevents HDACi-induced Epstein-Barr virus reactivation through the PKG pathway in NK/T cell lymphoma; potential implications for HDACi-mediated fatal complications

Romidepsin, a histone deacetylase (HDAC) inhibitor, has been approved for the treatment of relapsed and refractory peripheral T-cell lymphoma. However the use of romidepsin reportedly causes potent EBV (Epstein-Barr virus) reactivation leading to severe adverse events in patients with natural killer (NK)/T-cell lymphoma (NKTL). As inhibition of EBV lytic cycle reactivation may help prevent romidepsin-induced adverse events in NKTL, we herein set out to identify a safe and effective drug for inhibiting EBV reactivation and examine its mechanism of inhibition. EBV reactivation was evaluated by qRT-PCR of BZLF1 and BRLF1 mRNA expression, qPCR of EBV DNA, and immunoblotting of viral EA-D protein. High-throughput screening of FDA-approved drugs was performed to identify safe and effective molecules and test their effect on romidepsin-induced EBV reactivation in the EBV-positive NKTL cell lines, SNK6 and NK92MI. We found that phosphodiesterase 5 (PDE5) inhibitors, including sildenafil (Viagra; Pfizer), appeared to be nontoxic and effective inhibitors of romidepsin-induced EBV reactivation. Clinical relevance was investigated by qPCR of EBV in two primary effusion samples of NKTL patients. We also investigated the molecular consequences downstream of sildenafil-induced PDE5 inhibition in NKTL cells. A negative correlation was established between the cGMP/PKG pathway and EBV reactivation in NKTL cells. On a molecular level, PDE5 inhibition downregulates BZLF1 and BRLF1 through cGMP/PKG signaling-induced ZNF overexpression. Co-treatment with romidepsin and sildenafil (inhibiting HDAC and PDE5, respectively) showed a synergistic inhibitory effect on NKTL cells, highlighting PDE5 as an attractive target for future therapy in NKTL.

Inhibitors of APE1 redox function effectively inhibit γ-herpesvirus replication in vitro and in vivo

APE1 is a multi-functional protein with a redox function in its N-terminal domain and an apurinic/apyrimidinic endonuclease activity in the C-terminal domain. APE1 redox function plays an important role in regulating cell proliferation and survival through activating specific transcriptional activators. APE1 redox function is also found to be associated with some cancer occurrence. In this study, we demonstrated that APE1 redox function is essential for Epstein-Barr virus (EBV) lytic replication as the silencing of APE1 expression or treatment with APE1 redox inhibitors C10 and E3330 can inhibit EBV lytic replication and virion production. Furthermore, C10 and E3330 also inhibit MHV-68 replication in vitro and in vivo. C10 and E3330 were able to significantly reduce the loss of pulmonary alveoli and thickening of alveolar septa in mice caused by MHV-68 infection. Altogether, (i) APE1 redox function is validated as a new antiviral target; (ii) APE1 redox inhibitors, especially C10, have potentials to be used for the treatment of γ-herpesvirus infection and associated diseases; (iii) MHV-68 is validated to be a surrogate for the study of the pathogenesis and therapy of EBV and KSHV infection in vivo.

Clinical characteristics of Epstein-Barr virus infection in the pediatric nervous system

BACKGROUND

To investigate the clinical characteristics of Epstein-Barr virus (EBV) infection in the pediatric nervous system (NS).

METHODS

We retrospectively analyzed the clinical data and follow-up results of 89 children with neurological damage caused by EBV who were hospitalized in the children's hospital of Chongqing Medical University from January 2008 to April 2019.

RESULTS

EBV infection of the NS can occur at any time of the year. The highest incidence was seen in the age group of 0-4 years. Fever is the main clinical feature (74/89, 83.1%). The main clinical types were encephalitis/meningoencephalitis (64/89, 71.9%), acute myelitis (2/89, 2.2%), acute disseminated encephalomyelitis (ADEM) (3/89, 3.4%), Guillain-Barré Syndrome (GBS) (15/89, 16.9%), neurological damage caused by EBV-hemophagocytic lymphohistiocytosis (EBV-HLH) (4/89, 4.5%), and NS-post-transplant lymphoproliferative disorder (NS-PTLD) (1/89, 1.1%). Anti-N-methyl-D-aspartate receptor encephalitis was found during the convalescence of EBV encephalitis. EBV encephalitis/meningitis showed no symptoms of tonsillitis, lymph node enlargement, skin rash, hepatosplenomegaly. Acute motor axonal neuropathy is the chief complication in GBS caused by EBV.

CONCLUSION

There were significant differences in neurological complications caused by EBV. The prognosis of EBV infection in the NS is generally good. These illnesses are often self-limiting. A few cases may show residual sequelae.

Proteomic approaches to investigate gammaherpesvirus biology and associated tumorigenesis

The DNA viruses, Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV), are members of the gammaherpesvirus subfamily, a group of viruses whose infection is associated with multiple malignancies, including cancer. The primary host for these viruses is humans and, like all herpesviruses, infection with these pathogens is lifelong. Due to the persistence of gammaherpesvirus infection and the potential for cancer formation in infected individuals, there is a driving need to understand not only the biology of these viruses and how they remain undetected in host cells but also the mechanism(s) by which tumorigenesis occurs. One of the methods that has provided much insight into these processes is proteomics. Proteomics is the study of all the proteins that are encoded by a genome and allows for (i) identification of existing and novel proteins derived from a given genome, (ii) interrogation of protein-protein interactions within a system, and (iii) discovery of druggable targets for the treatment of malignancies. In this chapter, we explore how proteomics has contributed to our current understanding of gammaherpesvirus biology and their oncogenic processes, as well as the clinical applications of proteomics for the detection and treatment of gammaherpesvirus-associated cancers.