Epstein-Barr virus: general factors, virus-related diseases and measurement of viral load after transplant

The viral landscape in metastatic solid cancers

Here, we analyze the viral landscape in blood and tissue from 4918 metastatic cancer patients across 38 solid cancer types from the Hartwig Medical Foundation (HMF) cohort, the largest pan-cancer study on metastatic cancer. Using a coverage-based filtering approach, we detected 25 unique viral genera across 32 different cancer types, with a total of 747 unique virus-positive tissue samples. We detected 336 virus-positive blood samples across 29 cancer types, dominated by Torque teno virus and Alphatorquevirus. The tissue samples were dominated by Alphapapillomavirus and Roseolovirus. Alphapapillomavirus was significantly enriched in genital, anal, and colorectal cancers and was associated with host mutational signatures and transcriptional programs related to immunity and DNA repair. Host genes with Alphapapillomavirus integration tended to be more highly expressed and samples with HPV integration had higher somatic mutation rates and higher number of extrachromosomal DNA elements. Alphapapillomavirus was also detected in a significant proportion of blood samples from cervix and anal cancers, suggesting a potential blood-based biomarker.

Viruses tipping the scales: The role of the CD4/CD8 ratio in determining viral outcome

Here we review recent data on how animal viruses alter the T cell dynamics, and how stressed T cell populations alter viral disease outcomes. The CD4/CD8 ratio of T cells is regulated by the thymus well into adulthood, and determined by both host genetics and environmental exposures. Human and animal data now show many chronic viral infections interact with this ratio and Immune Health Grades, but this raises new questions and justifies new experimental systems. Immune Health Grades and the ratio generally can quantify subtle immunodeficiency for viral infections. Whether or not an animal recovers from a viral infection, and how carcinogenisis proceeds for certain oncogenic viral infections can now be traced back to how "stressed that animal's immune system is as judged by a low CD4/CD8 ratio or elevated Immune Health Grade. We provide this review to encourage basic science virologists using animal models and veterinary virologists to further explore the interactions between the CD4/CD8 T cell ratio and viruses to improve both human and veterinary health.

A comprehensive review of research advances in the study of lactoferrin to treat viral infections

Lactoferrin (Lf) is a naturally occurring glycoprotein known for its antiviral and antibacterial properties and is present in various physiological fluids. Numerous studies have demonstrated its antiviral effectiveness against multiple viruses, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza virus (IFV), herpes simplex virus (HSV), hepatitis B virus (HBV), and human immunodeficiency virus (HIV). Lf, a vital component of the mucosal defense system, plays a crucial role in inhibiting viral infection by binding to both host cells and viral particles, such as the Hepatitis C virus (HCV). This interaction enables Lf to keep viral particles away from their target cells, emphasizing its significance as a fundamental element of mucosal defense against viral infections. Additionally, Lf has the ability to modulate cytokine expression and enhance cellular immune responses. In the innate immune system, Lf serves as a unique iron transporter and helps suppress various pathogens like bacteria, fungi, and viruses. This article summarises the potential antiviral properties of Lf against various viruses, along with its other mentioned functions. The advancement of Lf-based therapies supports the homology of food and medicine, providing a promising avenue to address viral infections and other public health challenges.

Fatal Fulminant Epstein-Barr Virus (EBV) Encephalitis in Immunocompetent 5.5-Year-Old Girl-A Case Report with the Review of Diagnostic and Management Dilemmas

INTRODUCTION

Epstein-Barr virus (EBV) usually causes mild, self-limiting, or asymptomatic infection in children, typically infectious mononucleosis. The severe course is more common in immunocompromised patients. Neurological complications of primary infection, reactivation of the latent infection, or immune-mediated are well-documented. However, few published cases of fatal EBV encephalitis exist. Case presentation We report a case of a 5.5-year-old immunocompetent girl with fulminant EBV encephalitis fulfilling the criteria for the recently proposed subtype Acute Fulminant Cerebral Edema: (AFCE). The child presented with fever, vomiting, altered mental status, and ataxia. Her initial brain CT (computed tomography) scan was normal. On day 2 she developed refractory status epilepticus requiring intubation, ventilation, and sedation for airway protection and seizure control. Magnetic resonance imaging (MRI) scan showed cytotoxic brain edema. Despite intensive treatment, including acyclovir, ceftriaxone, hyperosmotic therapy (3% NaCl), intravenous immunoglobulins (IVIG), corticosteroids, as well as supportive management, on day 5 she developed signs of impending herniation. Intensification of therapy (hyperventilation, deepening sedation, mannitol) was ineffective, and a CT scan demonstrated generalized brain edema with tonsillar herniation. EBV primary infection was confirmed by serology and qPCR in blood samples and post-mortem brain tissue. An autopsy was consistent with the early phase of viral encephalitis. Conclusions This case confirms that normal or non-specific CT and MRI scans do not exclude encephalitis diagnosis if clinical presentation fulfills the diagnostic criteria. The implementation of prophylactic anticonvulsants could improve outcomes. Intracranial pressure (ICP) monitoring should be considered in AFCE for better ICP management. Decompressive craniectomy might be a life-saving option in refractory cases. An encephalitis management algorithm is proposed.

Leukemia in pregnancy: Diagnosis and therapeutic approach (Review)

The present study aimed to evaluate the epidemiological, diagnostic and therapeutic data of hematological malignancies in pregnancy. Leukemia in pregnancy is rare, and literature data are not extensive. Risk factors, epidemiology and pathogenesis of these diseases are not fully developed. Furthermore, there is a detailed report on the complications in pregnancy and the overall (per trimester) management of these diseases, specifically their treatment strategy. The possibility of achieving a future pregnancy in women with leukemia is described in the present study. The limited clinical research data currently available is mainly due to the inability to conduct randomized clinical trials for ethical reasons. Further research is needed, firstly due to the importance of these diseases for the pregnant woman and the fetus, and secondly, due to the continuous development of novel anticancer drugs that aim to improve the prognosis of these diseases.

Immune Modulation by Epstein-Barr Virus Lytic Cycle: Relevance and Implication in Oncogenesis

EBV infects more than 90% of people globally, causing lifelong infection. The phases of the EBV life cycle encompass primary infection, latency, and subsequent reactivation or lytic phase. The primary infection usually happens without noticeable symptoms, commonly in early life stages. If it manifests after childhood, it could culminate in infectious mononucleosis. Regarding potential late consequences, EBV is associated with multiple sclerosis, rheumatoid arthritis, chronic active EBV infection, lymphomas, and carcinomas. Previous reports that the lytic phase plays a negligible or merely secondary role in the oncogenesis of EBV-related tumors are steadily losing credibility. The right mechanisms through which the lytic cycle contributes to carcinogenesis are still unclear, but it is now recognized that lytic genes are expressed to some degree in different cancer-type cells, implicating their role here. The lytic infection is a persistent aspect of virus activity, continuously stimulating the immune system. EBV shows different strategies to modulate and avoid the immune system, which is thought to be a key factor in its ability to cause cancer. So, the principal goal of our review is to explore the EBV's lytic phase contribution to oncogenesis.

Atypical Presentation of Epstein-Barr Virus Infectious Mononucleosis With Cholestatic Hepatitis and Hyperbilirubinemia in a Young Adult: A Case Report

This case report details the presentation of a 24-year-old male of South Asian descent with an atypical manifestation of Epstein-Barr virus (EBV) infectious mononucleosis, characterized by cholestatic hepatitis and hyperbilirubinemia. The patient initially presented with common symptoms of sore throat, intermittent fever, and general malaise, which subsequently progressed to include nausea and vomiting. Laboratory investigations revealed significantly elevated liver enzymes and bilirubin levels. Comprehensive serological testing confirmed an EBV infection. Despite the absence of typical risk factors, this case underscores the importance of considering EBV in the differential diagnosis for young adults presenting with both infectious symptoms and abnormal liver function tests. Early recognition of such atypical presentations is crucial for guiding appropriate management and avoiding unnecessary diagnostic procedures.

Risk of inflammatory bowel disease following hospitalisation with infectious mononucleosis: nationwide cohort study from Denmark

Infectious mononucleosis (IM) is suspected to be associated with inflammatory bowel disease (IBD) development. Using a Danish nationwide cohort of people developing severe IM and their age-, sex-, and socioeconomic (SES) index-matched counterparts, we investigated the subsequent risk of IBD, Crohn's disease (CD), or ulcerative colitis (UC) development from 1977 to 2021. Among 39,684 severe IM patients we find a sex-, age-, and SES index-adjusted HR for IBD of 1.35 (95% CI: 1.22-1.49). This significantly increased risk was seen for both CD (HR: 1.56; 95% CI: 1.34-1.83) and to a lesser extent UC (HR: 1.23; 95% CI: 1.08-1.40) and remains following negative control matching with a cohort diagnosed with Chlamydia trachomatis infection (HR: 1.39; 95% CI: 1.01-1.91). Those with severe IM at 0-9 years had a particularly increased risk for CD (HR: 1.77; 95% CI: 1.26-2.49). Here we show an increased risk for IBD diagnosis following IM hospitalisation, indicating an association between severe EBV disease and later IBD development. Further exploration of the potential factors contributing to IBD susceptibility following EBV disease is warranted.

Viral infections in etiology of mental disorders: a broad analysis of cytokine profile similarities - a narrative review

The recent pandemic caused by the SARS-CoV-2 virus and the associated mental health complications have renewed scholarly interest in the relationship between viral infections and the development of mental illnesses, a topic that was extensively discussed in the previous century in the context of other viruses, such as influenza. The most probable and analyzable mechanism through which viruses influence the onset of mental illnesses is the inflammation they provoke. Both infections and mental illnesses share a common characteristic: an imbalance in inflammatory factors. In this study, we sought to analyze and compare cytokine profiles in individuals infected with viruses and those suffering from mental illnesses. The objective was to determine whether specific viral diseases can increase the risk of specific mental disorders and whether this risk can be predicted based on the cytokine profile of the viral disease. To this end, we reviewed existing literature, constructed cytokine profiles for various mental and viral diseases, and conducted comparative analyses. The collected data indicate that the risk of developing a specific mental illness cannot be determined solely based on cytokine profiles. However, it was observed that the combination of IL-8 and IL-10 is frequently associated with psychotic symptoms. Therefore, to assess the risk of mental disorders in infected patients, it is imperative to consider the type of virus, the mental complications commonly associated with it, the predominant cytokines to evaluate the risk of psychotic symptoms, and additional patient-specific risk factors.

Deciphering the Association of Epstein-Barr Virus and Its Glycoprotein M Peptide with Neuropathologies in Mice

The reactivation of ubiquitously present Epstein-Barr virus (EBV) is known to be involved with numerous diseases, including neurological ailments. A recent in vitro study from our group unveiled the association of EBV and its 12-amino acid peptide glycoprotein M146-157 (gM146-157) with neurodegenerative diseases, viz., Alzheimer's disease (AD) and multiple sclerosis. In this study, we have further validated this association at the in vivo level. The exposure of EBV/gM146-157 to mice causes a decline in the cognitive ability with a concomitant increase in anxiety-like symptoms through behavioral assays. Disorganization of hippocampal neurons, cell shrinkage, pyknosis, and apoptotic appendages were observed in the brains of infected mice. Inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were found to be elevated in infected mouse brain tissue samples, whereas TNF-α exhibited a decline in the serum of these mice. Further, the altered levels of nuclear factor-kappa B (NF-kB) and neurotensin receptor 2 affirmed neuroinflammation in infected mouse brain samples. Similarly, the risk factor of AD, apolipoprotein E4 (ApoE4), was also found to be elevated at the protein level in EBV/gM146-157 challenged mice. Furthermore, we also observed an increased level of myelin basic protein in the brain cortex. Altogether, our results suggested an integral connection of EBV and its gM146-157 peptide to the neuropathologies.

Chronic Viral Infections and Cancer, Openings for Therapies and Vaccines

Infections are responsible for approximately one out of six cases of cancer worldwide [...].

Multiple Sclerosis Risk Among Anti-tumor Necrosis Factor Alpha Users: A Methodological Review of Observational Studies Based on Real-world Data

Epidemiologic studies on the risk of multiple sclerosis (MS) or demyelinating events associated with anti-tumor necrosis factor alpha (TNFα) use among patients with rheumatic diseases or inflammatory bowel diseases have shown conflicting results. Causal directed acyclic graphs (cDAGs) are useful tools for understanding the differing results and identifying the structure of potential contributing biases. Most of the available literature on cDAGs uses language that might be unfamiliar to clinicians. This article demonstrates how cDAGs can be used to determine whether there is a confounder, a mediator or collider-stratification bias and when to adjust for them appropriately. We also use a case study to show how to control for potential biases by drawing a cDAG depicting anti-TNFα use and its potential to contribute to MS onset. Finally, we describe potential biases that might have led to contradictory results in previous studies that examined the effect of anti-TNFα and MS, including confounding, confounding by contraindication, and bias due to measurement error. Clinicians and researchers should be cognizant of confounding, confounding by contraindication, and bias due to measurement error when reviewing future studies on the risk of MS or demyelinating events associated with anti-TNFα use. cDAGs are a useful tool for selecting variables and identifying the structure of different biases that can affect the validity of observational studies.

EBV-Associated Smooth Muscle Tumor in the Malar Area of an HIV-Positive Patient: A Case Report

BACKGROUND

EBV-associated smooth muscle tumors (EBV-SMTs) are rare and typically develop in individuals with a compromised immune system, particularly those who have acquired immunodeficiency syndrome (AIDS) or who have undergone organ transplants.

METHODS

We document a case of EBV-SMT in an HIV-positive 25-year-old man. The lesion was incised and assessed histologically and a panel of immune markers were performed. EBV association was demonstrated by in situ hybridization for EBV-encoded RNA (EBER-ISH).

RESULTS

Microscopically, the tumor composed of mildly pleomorphic, ovoid to spindled cells with numerous slit-like vascular channels. The tumor cells exhibited diffuse and strong immunoreactivity for smooth muscle actin (SMA) and focal positivity for h-caldesmon. EBER-ISH of the tumor cells revealed strong positive nuclear signals.

CONCLUSION

The histopathological features of EBV-SMT do not conform to either benign or malignant SMTs and it has a peculiar predilection to develop at sites unusual for leiomyoma or leiomyosarcoma. The key diagnostic features of EBV-SMT include history of immunosuppression, histologic evidence of primitive and mildly pleomorphic cells maintaining blunt nuclear features in most areas, and positivity for EBER-ISH.

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.

Epidemiology and clinical characteristics of Epstein-Barr virus infection among children in Shanghai, China, 2017-2022

Objective

To investigate the epidemiology and infectious characteristics of Epstein-Barr virus (EBV) infection among children in Shanghai, China from 2017 to 2022.

Methods

We conducted a retrospective analysis of 10,260 inpatient patients who were subjected EBV nucleic acid testing from July 2017 to December 2022. Demographic information, clinical diagnosis, laboratory findings, etc. were collected and analyzed. EBV nucleic acid testing were performed by real-time PCR.

Results

A total of 2192 (21.4%) inpatient children were EBV-positive, with the average age of 7.3 ± 0.1 y. EBV detection was stable from 2017 to 2020 (26.9~30.1%), but showed essential decreases in 2021 (16.0%) and 2022 (9.0%). EBV was highest (>30%) detected from three quarters (Q) including 2018-Q4, 2019-Q4 and 2020-Q3. There were 24.5% of EBV coinfection with other pathogens, including bacteria (16.8%), other viruses (7.1%) and fungi (0.7%). EBV viral loads increased when coinfecting with bacteria ((142.2 ± 40.1) ×10⁴/mL) or other viruses ((165.7 ± 37.4) ×10⁴/mL). CRP significantly increased in EBV/fungi coinfection, while procalcitonin (PCT) and IL-6 showed remarkable increases in EBV/bacteria coinfection. Most (58.9%) of EBV-associated diseases belonged to immune disorders. The primary EBV-related diseases were systemic lupus erythematosus (SLE, 16.1%), immunodeficiency (12.4%), infectious mononucleosis (IM, 10.7%), pneumonia (10.4%) and Henoch-schonlein purpura (HSP, 10.2%). EBV viral loads were highest ((233.7 ± 27.4) × 10⁴/mL) in patients with IM.

Conclusion

EBV was prevalent among children in China, the viral loads increased when coinfecting with bacteria or other viruses. SLE, immunodeficiency and IM were the primary EBV-related diseases.

Infectious mononucleosis presenting as near-fatal tracheal obstruction

Infectious mononucleosis (IM) caused by Epstein-Barr virus is a self-limiting condition and usually carries a benign course. It is usually seen in adolescents and young adults. However, complications can occur in a small percentage of patients such as splenic rupture, myocarditis, and meningitis. Tracheal obstruction as a result of IM is extremely rare. In this case report, we highlighted a rare complication of nearly fatal tracheal obstruction in a young patient of IM that was managed timely by emergency tracheostomy.

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.

Sequence variations of Epstein-Barr virus LMP1 gene in gastric cancer and chronic gastritis isolates from Iranian patients

Aim

The current study aimed to investigate sequence variations in the C-terminus of latent membrane protein 1 (LMP1) in Epstein-Barr virus (EBV) isolates from Iranian patients with chronic gastritis or gastric cancer (GC).

Background

LMP1, an essential viral oncoprotein, is the critical element in the immortalization of B cells. It contains a small twenty-four amino acid cytoplasmic N-terminal region, six transmembrane segments, and a two hundred amino acid cytoplasmic C-terminal domain. Most LMP1-mediated signal transduction events are moderated by some functional parts of the cytoplasmic C-terminal domain.

Methods

Thirty-two EBV-positive biopsy tissues were obtained from patients with gastric cancer and patients with chronic gastritis. The C-terminal nucleotide sequences of LMP1 were amplified using nested-PCR and analyzed by DNA sequencing.

Results

Four to eight copies of the 11 repeat elements (codon 254-302) were observed in the carboxyl-terminal site of patients, but no relationship was found between the number of repeat sequences and disease status. The 30-bp deletion corresponding to codon 345-354 of the B95-8 strain was observed in 34% of isolates, and the remaining samples were non-deleted. In the gastric cancer group, a higher number of 33-bp repeats (≥5 repeats) was observed in 30-bp-deletion (100%) than in non-deleted (42%) isolates, and the difference was statistically significant. Analysis revealed that a gastritis isolate may be the result of recombination between Alaskan and China1 strains.

Conclusion

Overall, the current results showed no association between C-terminal sequence variations of LMP1 and malignant or non-malignant isolate origin.

Indication of Neurodegenerative Cascade Initiation by Amyloid-like Aggregate-Forming EBV Proteins and Peptide in Alzheimer's Disease

The neurotropic potential of the Epstein-Barr virus (EBV) was demonstrated quite recently; however, the mechanistic details are yet to be explored. Therefore, the effects of EBV infection in the neural milieu remain underexplored. Previous reports have suggested the potential role of virus-derived peptides in seeding the amyloid-β aggregation cascade, which lies at the center of Alzheimer's disease (AD) pathophysiology. However, no such study has been undertaken to explore the role of EBV peptides in AD. In our research, ∼100 EBV proteins were analyzed for their aggregation proclivity in silico using bioinformatic tools, followed by the prediction of 20S proteasomal cleavage sites using online algorithms NetChop ver. 3.1 and Pcleavage, thereby mimicking the cellular proteasomal cleavage activity generating short antigenic peptides of viral origin. Our study reports a high aggregate-forming tendency of a 12-amino-acid-long (₁₄₆SYKHVFLSAFVY₁₅₇) peptide derived from EBV glycoprotein M (EBV-gM). The in vitro analysis of aggregate formation done using Congo red and Thioflavin-S assays demonstrated dose- and time-dependent kinetics. Thereafter, Raman spectroscopy was used to validate the formation of secondary structures (α helix, β sheets) in the aggregates. Additionally, cytotoxicity assay revealed that even a low concentration of these aggregates has a lethal effect on neuroblastoma cells. The findings of this study provide insights into the mechanistic role of EBV in AD and open up new avenues to explore in the future.

Epstein-Barr Virus DNA Exacerbates Colitis Symptoms in a Mouse Model of Inflammatory Bowel Disease

Infection with EBV has been associated with various inflammatory disorders including inflammatory bowel diseases (IBD). Contribution of this virus to intestinal disease processes has not been assessed. We previously detected that EBV DNA triggers proinflammatory responses via the activation of endosomal Toll-like receptor (TLR) signaling. Hence, to examine the colitogenic potential of EBV DNA, we used the dextran sodium sulfate (DSS) mouse colitis model. C57BL/6J mice received either DSS-containing or regular drinking water. Mice were then administered EBV DNA by rectal gavage. Administration of EBV DNA to the DSS-fed mice aggravated colonic disease activity as well as increased the damage to the colon histologic architecture. Moreover, we observed enhanced expression of IL-17A, IFNγ and TNFα in colon tissues from the colitis mice (DSS-treated) given the EBV DNA compared to the other groups. This group also had a marked decrease in expression of the CTLA4 immunoregulatory marker. On the other hand, we observed enhanced expression of endosomal TLRs in colon tissues from the EBV DNA-treated colitis mice. These findings indicate that EBV DNA exacerbates proinflammatory responses in colitis. The ubiquity of EBV in the population indicates that possible similar responses may be of pertinence in a relevant proportion of IBD patients.

Molecular Genetics in Epstein-Barr Virus-Associated Malignancies

Global genomic studies have detected the role of genomic alterations in the pathogenesis of Epstein–Barr virus (EBV)-associated tumors. EBV oncoproteins cause a vital shift of EBV from an infectious virus to an oncogenic form during the latent and lytic phase within the lymphoid B cells and epithelial cells. This epigenetic alteration modulates the virus and host genomes and inactivates and disrupts numerous tumor suppressors and signaling pathways. Genomic profiling has played the main role in identifying EBV cancer pathogenesis and its related targeted therapies. This article reviews the role of genetic changes in EBV-associated lymphomas and carcinomas. This includes the prolific molecular genesis, key diagnostic tools, and target-specific drugs that have been in recent clinical use.

Viral G protein-coupled receptors as modulators of cancer hallmarks

Herpesviruses encode transmembrane G protein-coupled receptors (GPCRs), which share structural homology to human chemokine receptors. These viral GPCRs include KSHV-encoded ORF74, EBV-encoded BILF1, and HCMV-encoded US28, UL33, UL78 and US27. Viral GPCRs hijack various signaling pathways and cellular networks, including pathways involved in the so-called cancer hallmarks as defined by Hanahan and Weinberg. These hallmarks describe cellular characteristics crucial for transformation and tumor progression. The cancer hallmarks involve growth factor-independent proliferation, angiogenesis, avoidance of apoptosis, invasion and metastasis, metabolic reprogramming, genetic instability and immune evasion amongst others. The role of beta herpesviruses modulating these cancer hallmarks is clearly highlighted by the proliferative and pro-angiogenic phenotype associated with KSHV infection which is largely ascribed to the ORF74-mediated modulation of signaling networks in host cells. For HCMV and Epstein-Bar encoded GPCRs, oncomodulatory effects have been described which contribute to the cancer hallmarks, thereby enhancing oncogenic development. In this review, we describe the main signaling pathways controlling the hallmarks of cancer which are affected by the betaherpesvirus encoded GPCRs. Most prominent among these involve the JAK-STAT, PI(3)K-AKT, NFkB and MAPK signaling nodes. These insights are important to effectively target these viral GPCRs and their signaling networks in betaherpesvirus-associated malignancies.

Targeting histone epigenetics to control viral infections

During the past decades, many studies have significantly broadened our understanding of complex virus-host interactions to control chromatin structure and dynamics.1, 2 However, the role and impact of such modifications during viral infections is not fully revealed. Indeed, this type of regulation is bidirectional between the virus and the host. While viral replication and gene expression are significantly impacted by histone modifications on the viral chromatin,³ studies have shown that some viral pathogens dynamically manipulate cellular epigenetic factors to enhance their own survival and pathogenesis, as well as escape the immune system defense lines.⁴ In this dynamic, histone posttranslational modifications (PTMs) appear to play fundamental roles in the regulation of chromatin structure and recruitment of other factors.⁵ Genuinely, those PTMs play a vital role in lytic infection, latency reinforcement, or, conversely, viral reactivation.⁶ In this chapter, we will examine and review the involvement of histone modifications as well as their potential manipulation to control infections during various viral life cycle stages, highlighting their prospective implications in the clinical management of human immunodeficiency virus (HIV), herpes simplex virus (HSV), human cytomegalovirus (HCMV), hepatitis B and C viruses (HBV and HCV, respectively), Epstein–Barr virus (EBV), and other viral diseases. Targeting histone modifications is critical in setting the treatment of chronic viral infections with both lytic and latent stages (HIV, HCMV, HSV, RSV), virus-induced cancers (HBV, HCV, EBV, KSHV, HPV), and epidemic/emerging viruses (e.g. influenza virus, arboviruses).

Epstein-Barr virus and skin

Epstein-Barr virus is a DNA virus infecting human beings and could affect 90% of human population. It is crucial to take in account that in Latin America, unlike what happens in developed countries, the exposure to the virus is very early and therefore people have a much longer interaction with the virus. The virus is related to many diseases, mainly the oncological ones, and when the onset is in cutaneous tissue, it can present many clinical variants, as well acute as chronic ones. Among the acute ones are infectious mononucleosis rash and Lipschutz ulcers; the chronic presentations are hypersensivity to mosquito bites, hydroa vacciniforme, hydroa vacciniforme-like lymphoma, its atypical variants and finally nasal and extra-nasal NK/T-cell lymphoma. Although they are not frequent conditions, it is crucial for the dermatologist to know them in order to achieve a correct diagnosis.

The Epstein-Barr virus LMP1 interactome: biological implications and therapeutic targets

The oncogenic potential of Epstein-Barr virus (EBV) is mostly attributed to latent membrane protein 1 (LMP1), which is essential and sufficient for transformation of fibroblast and primary lymphocytes. LMP1 expression results in the activation of multiple signaling cascades like NF-ΚB and MAP kinases that trigger cell survival and proliferative pathways. LMP1 specific signaling events are mediated through the recruitment of a number of interacting proteins to various signaling domains. Based on these properties, LMP1 is an attractive target to develop effective therapeutics to treat EBV-related malignancies. In this review, we focus on LMP1 interacting proteins, associated signaling events, and potential targets that could be exploited for therapeutic strategies.

Regulatory network analysis of Epstein-Barr virus identifies functional modules and hub genes involved in infectious mononucleosis

Epstein-Barr virus (EBV) is the most common cause of infectious mononucleosis (IM) and establishes lifetime infection associated with a variety of cancers and autoimmune diseases. The aim of this study was to develop an integrative gene regulatory network (GRN) approach and overlying gene expression data to identify the representative subnetworks for IM and EBV latent infection (LI). After identifying differentially expressed genes (DEGs) in both IM and LI gene expression profiles, functional annotations were applied using gene ontology (GO) and BiNGO tools, and construction of GRNs, topological analysis and identification of modules were carried out using several plugins of Cytoscape. In parallel, a human-EBV GRN was generated using the Hu-Vir database for further analyses. Our analysis revealed that the majority of DEGs in both IM and LI were involved in cell-cycle and DNA repair processes. However, these genes showed a significant negative correlation in the IM and LI states. Furthermore, cyclin-dependent kinase 2 (CDK2) - a hub gene with the highest centrality score - appeared to be the key player in cell cycle regulation in IM disease. The most significant functional modules in the IM and LI states were involved in the regulation of the cell cycle and apoptosis, respectively. Human-EBV network analysis revealed several direct targets of EBV proteins during IM disease. Our study provides an important first report on the response to IM/LI EBV infection in humans. An important aspect of our data was the upregulation of genes associated with cell cycle progression and proliferation.

Epstein-Barr virus serology and PCR: conflicting results in an immunocompetent host. A case report and review of literature

We present the case of a 27-year-old immunocompetent man who progressively developed a generalized lymphadenopathy and B symptoms. Results of Epstein-Barr virus (EBV) serology were suggestive for a past infection, but the EBV viral load in whole blood was high. Also, core needle biopsy of the largest lymph node showed an image which could fit an EBV-driven reactive lymphoproliferation. Despite the absence of an immune disorder, all medical evidence points to an EBV-driven lymphoproliferative proces. In immunocompetent patients, it seems extremely uncommon to detect a high EBV viral load in the absence of serological evidence of an acute EBV infection or reactivation. We reviewed literature on this topic and on the selection of the appropriate sample type for EBV PCR, as this is known to be a critical point. Serological testing for the diagnosis of EBV infection is the gold standard in immunocompetent patients. Measuring EBV viral load is only recommended when dealing with immunocompromised patients. Although extremely rare, this case report shows that there is a place for EBV PCR in certain situations in immunocompetent patients. Besides, there is still no consensus regarding the specimen of choice for the determination of the EBV viral load. The preferred specimen type seems to depend on the patient's underlying condition.