Herpesviruses and the microbiome

Extracellular vesicles in the pathogenesis of neurotropic viruses

Neurotropic viruses, characterized by their capacity to invade the central nervous system, present a considerable challenge to public health and are responsible for a diverse range of neurological disorders. This group includes a diverse array of viruses, such as herpes simplex virus, varicella zoster virus, poliovirus, enterovirus and Japanese encephalitis virus, among others. Some of these viruses exhibit high neuroinvasiveness and neurovirulence, while others demonstrate weaker neuroinvasive and neurovirulent properties. The clinical manifestations of infections caused by neurotropic viruses can vary significantly, ranging from mild symptoms to severe life-threatening conditions. Extracellular vesicles (EVs) have garnered considerable attention due to their pivotal role in intracellular communication, which modulates the biological activity of target cells via the transport of biomolecules in both health and disease. Investigating EVs in the context of virus infection is crucial for elucidating their potential role contribution to viral pathogenesis. This is because EVs derived from virus-infected cells frequently transfer viral components to uninfected cells. Importantly, EVs released by virus-infected cells have the capacity to traverse the blood-brain barrier (BBB), thereby impacting neuronal activity and inducing neuroinflammation. In this review, we explore the roles of EVs during neurotropic virus infections in either enhancing or inhibiting viral pathogenesis. We will delve into our current comprehension of the molecular mechanisms that underpin these roles, the potential implications for the infected host, and the prospective diagnostic applications that could arise from this understanding.

Ginkgolic acid inhibits the replication of pseudorabies virus in vitro and in vivo by suppressing the transcription of viral late genes

Pseudorabies virus (PRV) belongs to the species of alphaherpesvirus that can cause substantial economic losses to the world swine industry. Therefore, research on anti-PRV compounds is of great value. In this study, it was found that ginkgolic acid could efficiently inhibit the replication of PRV, and the IC50 and CC50 were 3.407 μM and 102.3 μM, respectively. Moreover, it was discovered that ginkgolic acid had no effect on the adsorption, entry, and release stages of the PRV replication cycle. Importantly, it was found that ginkgolic acid could significantly suppress the transcription of PRV late genes, while the transcription of viral immediate early and early genes was not affected. Finally, in vivo experiments showed that ginkgolic acid could significantly reduce the viral load of PRV in multiple tissues and increase 30% survival rate of mice upon the challenge of PRV. Taken together, a novel PRV replication inhibitor, ginkgolic acid, which worked through suppressing the transcription of the late genes, was found in this study. This study provides a potential therapy method for the infection of PRV.

N-Linked Glycosylation and Expression of Duck Plague Virus pUL10 Promoted by pUL49.5

Duck plague virus (DPV) is a member of the alphaherpesvirus subfamily, and its genome encodes a conserved envelope protein, protein UL10 (pUL10). pUL10 plays complex roles in viral fusion, assembly, cell-to-cell spread, and immune evasion, which are closely related to its protein characteristics and partners. Few studies have been conducted on DPV pUL10. In this study, we identified the characteristics of pUL10, such as the type of glycosylation modification and subcellular localization. The characteristic differences in pUL10 in transfection and infection suggest that there are other viral proteins that participate in pUL10 modification and localization. Therefore, pUL49.5, the interaction partner of pUL10, was explored. We found that pUL10 interacts with pUL49.5 during transfection and infection. Their interaction entailed multiple interaction sites, including noncovalent forces in the pUL49.5 N-terminal domains and C-terminal domains and a covalent disulfide bond between two conserved cysteines. pUL49.5 promoted pUL10 expression and mature N-linked glycosylation modification. Moreover, deletion of UL49.5 in DPV caused the molecular mass of pUL10 to decrease by approximately3 to 10 kDa, which suggested that pUL49.5 was the main factor affecting the N-linked glycosylation of DPV pUL10 during infection. This study provides a basis for future exploration of the effect of pUL10 glycosylation on virus proliferation. IMPORTANCE Duck plague is a disease with high morbidity and mortality rates, and it causes great losses for the duck breeding industry. Duck plague virus (DPV) is the causative agent of duck plague, and DPV UL10 protein (pUL10) is a homolog of glycoprotein M (gM), which is conserved in herpesviruses. pUL10 plays complex roles in viral fusion, assembly, cell-to-cell spread, and immune evasion, which are closely related to its protein characteristics and partners. In this study, we systematically explored whether pUL49.5 (a partner of pUL10) plays roles in the localization, modification, and expression of pUL10.

Epstein Barr virus infection in tree shrews alters the composition of gut microbiota and metabolome profile

BACKGROUND

Epstein-Barr virus (EBV) infection is a major global threat; its manifestations range from the absence of symptoms to multiorgan malignancies and various gastrointestinal diseases. Analyzing the composition and metabolomic profile of gut microbiota during acute EBV infection might be instrumental in understanding and controlling EBV.

METHODS

Six tree shrews were inoculated with EBV by intravenous injection. Blood was collected at regular intervals thereafter from the femoral vein to detect EBV and inflammatory biomarker. At the same time, tree shrew faeces were collected for 16 S rRNA gene sequencing and Non-targeted metabolomics analysis.

RESULTS

16 S rRNA gene characterization along with β diversity analysis exhibited remarkable alterations in gut microflora structure with a peak at 7 days post-infection(dpi). Some alterations in the relative richness of bacterial taxon were linked to infectious indicators. Of note, Butyricicoccus relative richness was positively linked to EBV presence in the blood and plasma, the opposite correlation was seen with Variovorax and Paramuribaculum. Non-targeted metabolomics indicated the fecal metabolome profile altered during EBV infection, particularly 7 dpi. The relative abundance of geranic acid and undecylenic acid in stool samples was positively linked to systemic inflammatory biomarkers, and an inverse relationship was reported with the estrone glucuronide, linoleic acid, protoporphyrin IX and tyramine.

CONCLUSION

Collectively, EBV infection in this model correlated with changes in the composition and metabolome profile of the gut microbiota.

Infections in Burn Patients

Infections are the leading cause of mortality in burn patients who survive their initial resuscitation. Burn injury leads to immunosuppression and a dysregulated inflammatory response which can have a prolonged impact. Early surgical excision along with support of the multidisciplinary burn team has improved mortality in burn patients. The authors review diagnostic and therapeutic challenges as well as strategies for management of burn related infections.

How Does Epstein–Barr Virus Interact With Other Microbiomes in EBV-Driven Cancers?

The commensal microbiome refers to a large spectrum of microorganisms which mainly consists of viruses and bacteria, as well as some other components such as protozoa and fungi. Epstein–Barr virus (EBV) is considered as a common component of the human commensal microbiome due to its spread worldwide in about 95% of the adult population. As the first oncogenic virus recognized in human, numerous studies have reported the involvement of other components of the commensal microbiome in the increasing incidence of EBV-driven cancers. Additionally, recent advances have also defined the involvement of host–microbiota interactions in the regulation of the host immune system in EBV-driven cancers as well as other circumstances. The regulation of the host immune system by the commensal microbiome coinfects with EBV could be the implications for how we understand the persistence and reactivation of EBV, as well as the progression of EBV-associated cancers, since majority of the EBV persist as asymptomatic carrier. In this review, we attempt to summarize the possible mechanisms for EBV latency, reactivation, and EBV-driven tumorigenesis, as well as casting light on the role of other components of the microbiome in EBV infection and reactivation. Besides, whether novel microbiome targeting strategies could be applied for curing of EBV-driven cancer is discussed as well.

Acute periapical abscesses in patients with herpes simplex type 1 and herpes zoster

Aim: To assess the prevalence of acute periapical abscesses (PAs) in patients infected with herpes simplex type 1 (HS-1) and herpes zoster (HZ). Materials and methods: Integrated data of hospital patients was used. History of HS-1 and HZ diagnosis was retrieved by searching the appropriate query in the database. All cases were diagnosed for acute PAs by calibrated dentists in a hospital setting for patients admitted to urgent care. Diagnosis was made based on clinical examination and imaging data confirming the diagnosis of acute PAs without sinus tract. The odds ratio (OR) for the prevalence of acute PAs and its association with history of HS-1 and HZ were then calculated. Results: The prevalence of acute PAs in patients with a history HS-1 was 2.43% as compared to 0.59% in the general patient population of the hospital. The OR was 4.12 and the difference in prevalence was statistically significant (p < 0.0001). The prevalence of acute PAs in patients with a history HZ was 2.78% as compared to 0.59% in the general patient population of the hospital. The OR was 4.71 and the difference in prevalence was statistically significant (p < 0.0001). Conclusions: Under the conditions of this study, it appears that the prevalence of acute PAs is significantly higher in patients with a history of HS-1 and HZ infections and may warrant an antiviral therapy in certain resistant periapical abscesses.

Lung virome: New potential biomarkers for asthma severity and exacerbation

BACKGROUND

Although some respiratory virus infections are known to contribute to the development and exacerbation of asthma, commensal viromes in airway have not been extensively studied due to technical challenges.

OBJECTIVES

This study investigated the characteristics of the virome in asthmatic airways.

METHODS

Both the bacteriome and virome profiles in sputum from 12 healthy individuals, 15 patients with nonsevere asthma, and 15 patients with severe asthma were analyzed and assessed for the association with clinical characteristics such as severity, exacerbation, Asthma Control Test (ACT), and lung function.

RESULTS

While analysis of the 16S ribosomal RNA bacteriome in the airway showed no differences, clear contrasts in the diversity and composition of airway viromes were observed between healthy controls and patients with asthma. Herpesviruses were the most abundant type of virus in the asthma group (44.6 ± 4.6%), mainly with cytomegalovirus (CMV) and EBV accounting for 24.5 ± 3.3% and 16.9 ± 3.5%, respectively, in contrast to those in the healthy controls (5.4 ± 2.5% and 7.1 ± 3.0%, respectively). CMV and EBV were more abundant in patients with asthma who experienced exacerbation, and their abundance showed correlation with more severe asthma, lower ACT score, and lower lung function. On the contrary, bacteriophage that is abundant in healthy controls was severely reduced in patients with asthma in the order of nonsevere and severe asthma and presented significant positive correlation with ACT and FEV₁/forced vital capacity.

CONCLUSIONS

Lung viromes, especially, CMV, EBV, and bacteriophage may be potential biomarkers of asthma severity and exacerbation.

Viral Infections in Burns

Background: Viral infections after burns are less common than bacterial infections but usually occur in the more severely burned patients and have been associated with poor outcomes. Methods: Retrospective reviews and case series were examined to provide an overview of the management of viral infections in the burn patient. Results: The most common viral pathogens in these patients are the herpesviruses, which include herpes simplex, varicella zoster, cytomegalovirus, and human herpesvirus 6. Established viral infections that may complicate patient management include human immunodeficiency virus, hepatitis B and C, and, more recently, the novel coronavirus SARS-CoV-2. Herpesvirus infections can occur as primary or nosocomial pathogens but clinical manifestations most commonly are re-activation of latent viral infection. Because of the paucity of data in the burn population, much of the evidence for specific treatments is extrapolated from patients with severe immunosuppression or critical illness. Antiviral therapy is employed for the burn patient with herpesvirus infections. This is an area of active study, and further research is needed to better understand the risks, clinical manifestations, and attributable morbidity and mortality of viral infections. Conclusions: Major burn injury results in immunosuppression and viral infection in a small number of patients. Recognition and antiviral therapy are employed, but additional studies are necessary to improve outcomes in these patients.

The influence of Epstein-Barr virus and cytomegalovirus on childhood respiratory health: A population-based prospective cohort study

Background

Epstein‐Barr virus (EBV) and cytomegalovirus (CMV) infection are common in early childhood. CMV infection favours a T‐helper‐1 and EBV infection a T‐helper‐2 cell response, possibly leading to disbalanced T‐helper cell response, and subsequent risk of asthma or atopy.

Objective

To study the associations of EBV and CMV with lung function, asthma and inhalant allergic sensitization at school age.

Methods

This study among 3546 children was embedded in a population‐based prospective cohort. At age 6 years, serum IgG levels against EBV and CMV were measured by ELISA. At age 10 years, lung function was measured by spirometry, asthma by questionnaire and inhalant allergic sensitization by skin prick test.

Results

Unadjusted models showed that seropositivity for EBV was associated with a higher FEV₁ and FEF₇₅ (Z‐score difference (95% CI): 0.09 (0.02, 0.16) and 0.09 (0.02, 0.15)), while seropositivity for CMV was not. Specific combinations of viruses showed that seropositivity for EBV was only associated with FEV₁ and FEF₇₅ in the presence of seropositivity for CMV (0.12 (0.04, 0.20)) and 0.08 (0.01, 0.15)). Seropositivity for CMV in the absence of seropositivity for EBV was associated with an increased risk of inhalant allergic sensitization (OR (95% CI): 1.31 (1.02, 1.68)). All effect estimates attenuated into non‐significant mainly after adjustment for child's ethnicity. Seropositivity for EBV or CMV was not associated with asthma.

Conclusions and Clinical Relevance

Associations of EBV and CMV infections in early childhood with school‐age lung function and inhalant allergic sensitization are explained by ethnicity, or sociodemographic and lifestyle‐related factors.

Maternal and neonatal infections of herpes simplex virus-1 and cytomegalovirus in Saudi Arabia

It is common practice to screen for human cytomegalovirus (CMV) and herpes simplex virus (HSV) among women with infertility problems, recurrent abortion or exhibiting intrauterine growth restriction during pregnancy. Nonetheless, limited information exists about the incidence of these viruses in Saudi Arabia. The IgG and IgM antibodies of 761 women and 85 of neonates who showed intrauterine growth retardation (IUGR) were reviewed against cytomegalovirus and herpes simplex virus-1. Tests were repeated only for those with positive results. Recent infection of herpes simplex virus-1 and cytomegalovirus was evidenced by the presence of IgM in the female patients: incidence was 1.1% and 1.3% respectively. None of the neonates showed positive IgM for cytomegalovirus, but a single case showed a positive result for herpes simplex virus-1 IgM. Among the female patients, however, the presence of IgG indicated previous exposure to cytomegalovirus in 92% of cases and herpes simplex virus in 80.8%. It was concluded that although previous exposure to CMV and HSV-1 were found in high percentages in women experiencing infertility problems but did not appear to be associated with neonates exhibiting intrauterine growth retardation.

Variation of clinical manifestations according to culprit drugs in DRESS syndrome

PURPOSE

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a rare but serious condition that systematically damages various internal organs through T-cell-mediated immunological drug reactions. We aimed to investigate whether clinical manifestations of DRESS syndrome differ according to culprit drugs.

METHODS

We retrospectively analyzed data from 123 patients with probable/definite DRESS syndrome based on the RegiSCAR criteria (January 2011 to July 2016). The data were obtained from the Korean Severe Cutaneous Adverse Reaction Registry. Causality was assessed using the World Health Organization-Uppsala Monitoring Centre criteria. The culprit drugs were categorized as allopurinol, carbamazepine, anti-tuberculosis drug, vancomycin, cephalosporins, dapsone, and nonsteroidal anti-inflammatory drugs.

RESULTS

Differences were observed among culprit drugs regarding the frequencies of hepatitis (P < 0.01), renal dysfunction (P < 0.0001), lymphadenopathy (P < 0.01), and atypical lymphocyte (P < 0.01). Latency period differed among culprit drugs (P < 0.0001), being shorter in vancomycin and cephalosporin. In terms of clinical severity, admission duration (P < 0.01) and treatment duration (P < 0.05) differed among culprit drugs, being longer in vancomycin and anti-tuberculosis drugs, respectively.

CONCLUSIONS

Based on the findings, clinical manifestations, including latency period and clinical severity, may differ according to culprit drugs in DRESS syndrome.

Pleural effusions induced by human herpesviruses in the immunocompetent host

METHODS

A computer-based search of the English literature for articles relative to Human Herpesviruses (HHVs) infection and pleural effusions (PEs) in the immunocompetent host was performed in PubMed and Scopus. The reference lists of the retrieved articles were also reviewed for relevant articles.

RESULTS

A total of 20 articles satisfied the selection criteria and were included in the study. In the majority of the articles, PEs were reported as clinical complications of systemic HHV-induced infection. The frequency of HHVs within the reported cases was five for HHV-1/2, one for HHV-3, six for HHV-4, six for HHV-5 and one for HHV-6. One case involved HHV-4 and HHV-5 co-infection. No case of HHV-7 or HHV-8 related PE in the immunocompetent host was retrieved.

CONCLUSIONS

Pleural effusions in the immunocompetent host occur in severe viral infections and can be due to comorbidities (or septic complications) or due to the direct HHV pathogenicity although research relative to the susceptibility of pleural mesothelial cells to HHV infection is lacking. HHV pathogenicity needs to be studied further as it could explain undiagnosed PEs.

Microbiome-Mediated Upregulation of MicroRNA-146a in Sporadic Alzheimer's Disease

The first indication of a potential mechanistic link between the pathobiology of the human gastrointestinal (GI)-tract microbiome and its contribution to the pathogenetic mechanisms of sporadic Alzheimer's disease (AD) came a scant 4 years ago (1). Ongoing research continues to strengthen the hypothesis that neurotoxic microbial-derived components of the GI tract microbiome can cross aging GI tract and blood-brain barriers and contribute to progressive proinflammatory neurodegeneration, as exemplified by the AD-process. Of central interest in these recent investigations are the pathological roles played by human GI tract resident Gram-negative anaerobic bacteria and neurotropic viruses-two prominent divisions of GI tract microbiome-derived microbiota-which harbor considerable pathogenic potential. It is noteworthy that the first two well-studied microbiota-the GI tract abundant Gram-negative bacteria Bacteroides fragilis and the neurotropic herpes simplex virus-1 both share a final common pathway of NF-κB (p50/p65) activation and microRNA-146a induction with ensuing pathogenic stimulation of innate-immune and neuroinflammatory pathways. These appear to strongly contribute to the inflammation-mediated amyloidogenic neuropathology of AD. This communication: (i) will review recent research contributions that have expanded our understanding of the nature of the translocation of microbiome-derived neurotoxins-across biophysiological barriers; (ii) will assess multiple-recent investigations of the induction of the proinflammatory pathogenic microRNA-146a by these two prominent classes of human microbiota; and (iii) will discuss the role of molecular neurobiology and mechanistic contribution of polymicrobial infections to AD-type neuropathological change.

Cytomegalovirus DNA is highly prevalent in the blood of patients with asthma and is associated with age and asthma traits

Cytomegalovirus (CMV) IgG antibodies have been associated with inflammaging and immunosenescence. We aimed to assess the presence of CMV DNA in the blood of adult and elderly patients with bronchial asthma to establish potential association of CMV DNAemia with asthma and asthma characteristics. Eighty-five elderly asthmatics, 74 younger asthma patients, and 114 age-matched controls were recruited. The CMV DNA was detected using commercial artus assay in 10.7% of asthma patients, but was negative in all control individuals. The secondary assay identified CMV DNA in 41.5% of asthmatics and 13.3% of control subjects (P < .001). Presence of CMV DNA was associated with an increased risk of asthma and CMV DNA copy numbers correlated with some asthma traits, including respiratory parameters and exhaled breath nitric oxide. We conclude that CMV infection is associated with asthma and may contribute to the pathogenesis of asthmatic inflammation.

Extracellular vesicles: novel vehicles in herpesvirus infection

Herpesviruses are remarkable pathogens that have evolved multiple mechanisms to evade host immunity, ensuring their proliferation and egress. Among these mechanisms, herpesviruses utilize elaborate extracellular vesicles, including exosomes, for the intricate interplay between infected host and recipient cells. Herpesviruses incorporate genome expression products and direct cellular products into exosomal cargoes. These components alter the content and function of exosomes released from donor cells, thus affecting the downstream signalings of recipient cells. In this way, herpesviruses hijack exosomal pathways to ensure their survival and persistence, and exosomes are emerging as critical mediators for virus infection-associated intercellular communication and microenvironment alteration. In this review, the function and effects of exosomes in herpesvirus infection will be discussed, so that we will have a better understanding about the pathogenesis of herpesviruses.

Differential Diagnosis of Chronic Urticaria and Angioedema Based on Molecular Biology, Pharmacology, and Proteomics

Differential diagnosis of urticaria and angioedema has been based on the phenotype as either acute or chronic depending on the duration of more than 6 to 8 weeks, respectively. Additional subdivisions include poorly defined terms such as idiopathic, spontaneous, or autoimmune. In this article, the author suggests that an increased understanding of the acquired and innate immune system and data from novel proteomic technology have blurred the lines between these categories of diagnosis. Specific molecular pathways and response to specific medications should be incorporated in classification and diagnosis schemes.

Epigenetic Treatment of Persistent Viral Infections

Preclinical Research Approximately 2,500 years ago, Hippocrates used the word herpes as a medical term to describe lesions that appeared to creep or crawl on the skin, advocating heat as a possible treatment. During the last 50 years, pharmaceutical research has made great strides, and therapeutic options have expanded to include small molecule antiviral agents, protease inhibitors, preventive vaccines for a handful of the papillomaviruses, and even cures for hepatitis C virus infections. However, effective treatments for persistent and recurrent viral infections, particularly the highly prevalent herpesviruses, continue to represent a significant unmet medical need, affecting the majority of the world's population. Exploring the population diversity of the human microbiome and the effects its compositional variances have on the immune system, health, and disease are the subjects of intense investigational research and study. Among the collection of viruses, bacteria, fungi, and single-cell eukaryotes that comprise the human microbiome, the virome has been grossly understudied relative to the influence it exerts on human pathophysiology, much as mitochondria have until recently failed to receive the attention they deserve, given their critical biomedical importance. Fortunately, cellular epigenetic machinery offers a wealth of druggable targets for therapeutic intervention in numerous disease indications, including those outlined above. With advances in synthetic biology, engineering our body's commensal microorganisms to seek out and destroy pathogenic species is clearly on the horizon. This is especially the case given recent breakthroughs in genetic manipulation with tools such as the CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated) gene-editing platforms. Tying these concepts together with our previous work on the microbiome and neurodegenerative and neuropsychiatric diseases, we suggest that, because mammalian cells respond to a viral infection by triggering a cascade of antiviral innate immune responses governed substantially by the cell's mitochondria, small molecule carnitinoids represent a new class of therapeutics with potential widespread utility against many infectious insults. Drug Dev Res 78 : 24-36, 2017.   © 2016 Wiley Periodicals, Inc.

Increased seroprevalence of Enterovirus 71 IgE antibodies in asthmatic compared with non-asthmatic children

BACKGROUND

Asthma is a common pediatric chronic inflammatory airway disease. Respiratory viral infections are frequent infectious triggers for exacerbations of asthma.

OBJECTIVE

We sought to determine whether Enterovirus 71 (EV71), a ubiquitous virus that causes systemic inflammatory responses in children but is not a known respiratory pathogen, can also serve as an infectious trigger for asthma.

METHODS

Specific EV71 IgE and IgM antibodies (Abs), total serum IgE, and IL-2 and IL-4 cytokine levels in serum of asthmatic and non-asthmatic children (N = 42, ages 5-19; N = 35, ages 1-20, respectively) were measured (ELISA).

RESULTS

Asthmatic children had higher EV71 IgE Ab levels than non-asthmatic (P < 0.001). Non-asthmatic children had significantly higher EV71 IgM Ab levels than asthmatic (P < 0.001). Despite low serum IgE levels of non-asthmatic, compared with asthmatic (P < 0.001), the non-asthmatic children produced significantly more IL-2 and IL-4 than asthmatic (P < 0.001; P < 0.001). The ages of the asthmatics, but not the non-asthmatics had a significant effect on the levels of EV 71 IgE Abs (P = 0.02; P = 0.356). A test of difference between these two slopes was significant. However, the ages of the non-asthmatic, but not the asthmatic children had a significant effect on the levels of EV 71 IgM Abs; a test of difference between these two slopes was significant.

CONCLUSIONS

Increased specific EV71 IgE Ab responses may indicate that EV71 infection may also be an infectious trigger in asthma. However, the role of specific EV71 IgM Abs, Th2 cytokines, and age in non-asthmatic children should be further studied.

Determinants of Ethnic Differences in Cytomegalovirus, Epstein-Barr Virus, and Herpes Simplex Virus Type 1 Seroprevalence in Childhood

OBJECTIVE

To identify whether there are ethnic differences in cytomegalovirus (CMV), Epstein-Barr virus (EBV), and herpes simplex virus type 1 (HSV-1) seroprevalence rates in children at 6 years of age, and when present, to evaluate how these differences can be explained by sociodemographic and environmental factors.

STUDY DESIGN

This study was embedded within a multi-ethnic population-based prospective cohort study. Serum IgG levels against CMV, EBV, and HSV-1 were measured by enzyme-linked immunosorbent assay in 4464 children (median age 6.0 years). Information on demographics and characteristics were assessed by questionnaires. Herpesvirus seroprevalences between Surinamese-Creole, Surinamese-Hindustani, Turkish, Moroccan, Cape Verdean Antillean, and Native Dutch children were compared.

RESULTS

Non-Western ethnicity was an independent risk factor for CMV (aOR, 2.16; 95% CI 1.81-2.57), EBV (1.76; 1.48-2.09), and HSV-1 seropositivity (1.52; 1.39-1.66). Among the ethnic groups, CMV seroprevalences ranged between 29% and 65%, EBV between 43% and 69%, and HSV-1 between 13% and 39%. Low family net household income, low maternal educational level, crowding, and lifestyle factors explained up to 48% of the ethnic differences in HSV-1 seroprevalences, and up to 39% of the ethnic differences in EBV seroprevalences. These factors did not explain ethnic differences in CMV seroprevalences.

CONCLUSIONS

Socioeconomic position and factors related to lifestyle explain only a part of the large ethnic differences in EBV and HSV-1 seroprevalences, whereas they do not explain ethnic differences in CMV seroprevalences in childhood.

Herpes and polyoma family viruses in thyroid cancer

Thyroid cancer is considered the most common malignancy that affects the endocrine system. Generally, thyroid cancer derives from follicular epithelial cells, and thyroid cancer is divided into well-differentiated papillary (80% of cases) and follicular (15% of cases) carcinoma. Follicular thyroid cancer is further divided into the conventional and oncocytic (Hürthle cell) type, poorly differentiated carcinoma and anaplastic carcinoma. Both poorly differentiated and anaplastic carcinoma can arise either de novo, or secondarily from papillary and follicular thyroid cancer. The incidence of thyroid cancer has significantly increased for both males and females of all ages, particularly for females between 55–64 years of age, from 1999 through 2008. The increased rates refer to tumors of all stages, though they were mostly noted in localized disease. Recently, viruses have been implicated in the direct regulation of epithelial-mesenchymal transition (EMT) and the development of metastases. More specifically, Epstein-Barr virus (EBV) proteins may potentially lead to the development of metastasis through the regulation of the metastasis suppressor, Nm23, and the control of Twist expression. The significant enhancement of the metastatic potential, through the induction of angiogenesis and changes to the tumor microenvironment, subsequent to viral infection, has been documented, while EMT also contributes to cancer cell permissiveness to viruses. A number of viruses have been identified to be associated with carcinogenesis, and these include lymphotropic herpesviruses, namely EBV and Kaposi's sarcoma-associated herpesvirus [KSHV, also known as human herpesvirus type 8 (HHV8)]; two hepatitis viruses, hepatitis B virus (HBV) and hepatitis C virus (HCV); human papillomaviruses (HPVs); human T cell lymphoma virus (HTLV); and a new polyomavirus, Merkel cell polyomavirus identified in 2008. In this review, we examined the association between thyroid cancer and two oncogenic virus families, the herpes and polyoma family viruses, and we discuss their potential role as causative agents in thyroid carcinogenesis.

Autoimmune Limbic Encephalitis and Syndrome of Inappropriate Antidiuretic Hormone Secretion Associated with Lamotrigine-induced Drug Rash with Eosinophilia and Systemic Symptoms (DRESS) Syndrome

Drug rash with eosinophilia and systemic symptoms (DRESS) is a severe drug hypersensitivity reaction characterized by rash, fever and multi-organ failure. Limbic encephalitis (LE) is a rare disorder characterized by cognitive dysfunction with memory disturbance, seizures and psychiatric symptoms. We herein present an unusual case of DRESS syndrome due to lamotrigine with reactivation of Epstein-Barr virus, which developed autoimmune LE and syndrome of inappropriate antidiuretic hormone secretion. Discontinuation of lamotrigine, administration of methylprednisolone and intravenous immunoglobulin led to improvement. The LE in this case might have been caused by an autoimmune inflammatory mechanism associated with DRESS syndrome.

Serological evidence that activation of ubiquitous human herpesvirus-6 (HHV-6) plays a role in chronic idiopathic/spontaneous urticaria (CIU)

Acute infection with viral pathogens in the herpesviridae family can trigger acute urticaria, and reactivation of herpesviridae is associated with cutaneous urticarial-like syndromes such as drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms (DRESS). Reactivation of latent herpesviridae has not been studied systematically in chronic idiopathic/spontaneous urticaria (CIU). This review proposes that CIU is an inflammatory disorder with autoimmune features (termed 'CVU' for chronic viral urticaria), based on serology consistent with the hypothesis that reactivation of a latent herpesvirus or -viruses may play a role in CIU. Serology obtained from a cohort of omalizumab (Xolair)-dependent patients with severe CIU was consistent with previous HHV-6 infection, persistent viral gene expression and replication. CIU patients also exhibited serological evidence of increased immune response to HHV-4 (Epstein-Barr virus, or EBV) but not all CIU patients were infected with EBV. These observations, combined with case reports of CIU response to anti-viral therapy, suggest that HHV-6, possibly interacting with HHV-4 in cutaneous tissues, is a candidate for further prospective study as a co-factor in CIU.

Microbiome: Paediatricians' perspective

Millions of microorganisms inhabit the human body and affect its homeostasis in multiple ways. Alterations in this microbial community have implications for the health and survival of the human hosts. It is believed that these microorganisms should be included as part of the human genome because of their influence on human physiology hence the term "microbiome" is commonly used to refer to these microbes along with their genetic make-up and their environmental interactions. In this article we attempt to provide an insight into this recently discovered vital organ of the human body which is yet to be fully explored. We herein discuss the composition and role of microbiome in human health and disease with a special emphasis in children and culture-independent techniques employed in mapping of the microbiome. Alteration in the gut microbiome has been associated with causation of several paediatric diseases like infantile colic, necrotizing enterocolitis, asthma, atopy, obesity, type -1 diabetes, and autism. Atopic dermatitis and psoriasis have also been associated with changes in the cutaneous microbiome. Respiratory microbial imbalances during infancy have been linked with wheezing and bronchial asthma. Dysbiosis in the regional microbiome has been linked with caries, periodontitis, and chronic rhinosinusitis. The future therapeutic implications of this rapidly evolving area of research are also highlighted.

Detection of Epstein-Barr virus in different sources of materials from patients with oral lichen planus: a case-control study

AIMS

To detect the presence of Epstein-Barr virus (EBV) DNA in different sources of materials from a matched group of patients with oral lichen planus (OLP) and a group of people without OLP lesions, and to correlate the presence of virus with epidemiological variables of the groups studied.

METHODS

Fresh tissue samples, saliva, exfoliated cells and plasma of 24 patients with OLP lesions (cases) and 17 patients without OLP lesions (controls) were collected. EBV was detected by nested PCR.

RESULTS

Viral positivity was obtained in 62.5% of tissue samples; in 70.8% of exfoliated cell samples; in 33.3% of blood plasma samples and in 75% of saliva samples in the cases; and in 35.3% of tissue samples; 82.4% of exfoliated cell samples; in 47.1% of blood plasma samples and in 64.7% of saliva samples in the controls. There was a predominance of women in both groups. Variables not atrophic-erosive were most affected by EBV.

CONCLUSIONS

No relationship between EBV and OLP was found. However, all sources tested in this study were considered suitable for the detection of viruses.

Leprosy in the 21st century

Despite significant improvements in leprosy (Hansen's disease) treatment and outlook for patients since the introduction of multidrug therapy (MDT) 3 decades ago, the global incidence remains high, and patients often have long-term complications associated with the disease. In this article, we discuss recent findings related to genetics, susceptibility, and disease reservoirs and the implications of these findings for Hansen's disease control and health outcomes for patients. We describe the continued difficulties associated with treatment of inflammatory episodes known as "leprosy reactions," which cause much of the disability associated with the disease and can affect people for many years after MDT is complete. We also discuss some of the contemporary challenges for physicians and patients, including international and internal migration of people affected by the disease. We suggest some important areas of focus for future Hansen's disease research.

The evolution of the hygiene hypothesis: the role of early-life exposures to viruses and microbes and their relationship to asthma and allergic diseases

PURPOSE OF REVIEW

Understanding the mechanisms involved in the development of asthma and allergic diseases is expanding, due in part to sequencing advances that have led to the identification of new viral strains such as human rhinovirus strain C (HRV-C) and the human microbiome project.

RECENT FINDINGS

Recent studies have identified new ways in which viral and microbial exposures in early life interact with host genetic background/variants to modify the risk for developing asthma and allergic diseases. Recent research suggests that HRV-C is the main pathogenic agent associated with infant wheeze, hospitalizations and likely the subsequent development of asthma. Pulmonary He MRI suggests that HRV infection in early childhood and subsequent immune responses initiate airway remodeling. Numerous studies of the microbiome indicate that intestinal and airway microbiome diversity and composition contribute to the cause of asthma and allergic diseases.

SUMMARY

Susceptibility to asthma and allergic diseases is complex and involves genetic variants and environmental exposures (bacteria, viruses, smoking, and pet ownership), alteration of our microbiome and potentially large-scale manipulation of the environment over the past century.

Cytomegalovirus generates long-lived antigen-specific NK cells with diminished bystander activation to heterologous infection

Gundula Min-Oo and Lewis Lanier show that memory NK cells generated during MCMV infection respond poorly to cytokines generated during heterologous viral or bacterial infection, as compared with naïve NK cells.

Natural killer (NK) cells play a key role in the host response to cytomegalovirus (CMV) and can mediate an enhanced response to secondary challenge with CMV. We assessed the ability of mouse CMV (MCMV)–induced memory Ly49H⁺ NK cells to respond to challenges with influenza, an acute viral infection localized to the lung, and Listeria monocytogenes, a systemic bacterial infection. MCMV-memory NK cells did not display enhanced activation or proliferation after infection with influenza or Listeria, as compared with naive Ly49H⁺ or Ly49H⁻ NK cells. Memory NK cells also showed impaired activation compared with naive cells when challenged with a mutant MCMV lacking m157, highlighting their antigen-specific response. Ex vivo, MCMV-memory NK cells displayed reduced phosphorylation of STAT4 and STAT1 in response to stimulation by IL-12 and type I interferon (IFN), respectively, and IFN-γ production was reduced in response to IL-12 + IL-18 compared with naive NK cells. However, costimulation of MCMV-memory NK cells with IL-12 and m157 antigen rescues their impaired response compared with cytokines alone. These findings reveal that MCMV-primed memory NK cells are diminished in their response to cytokine-driven bystander responses to heterologous infections as they become specialized and antigen-specific for the control of MCMV upon rechallenge.

An attenuated herpes simplex virus type 1 (HSV1) encoding the HIV-1 Tat protein protects mice from a deadly mucosal HSV1 challenge

Herpes simplex virus types 1 and 2 (HSV1 and HSV2) are common infectious agents in both industrialized and developing countries. They cause recurrent asymptomatic and/or symptomatic infections, and life-threatening diseases and death in newborns and immunocompromised patients. Current treatment for HSV relies on antiviral medications, which can halt the symptomatic diseases but cannot prevent the shedding that occurs in asymptomatic patients or, consequently, the spread of the viruses. Therefore, prevention rather than treatment of HSV infections has long been an area of intense research, but thus far effective anti-HSV vaccines still remain elusive. One of the key hurdles to overcome in anti-HSV vaccine development is the identification and effective use of strategies that promote the emergence of Th1-type immune responses against a wide range of epitopes involved in the control of viral replication. Since the HIV1 Tat protein has several immunomodulatory activities and increases CTL recognition of dominant and subdominant epitopes of heterologous antigens, we generated and assayed a recombinant attenuated replication-competent HSV1 vector containing the tat gene (HSV1-Tat). In this proof-of-concept study we show that immunization with this vector conferred protection in 100% of mice challenged intravaginally with a lethal dose of wild-type HSV1. We demonstrate that the presence of Tat within the recombinant virus increased and broadened Th1-like and CTL responses against HSV-derived T-cell epitopes and elicited in most immunized mice detectable IgG responses. In sharp contrast, a similarly attenuated HSV1 recombinant vector without Tat (HSV1-LacZ), induced low and different T cell responses, no measurable antibody responses and did not protect mice against the wild-type HSV1 challenge. These findings strongly suggest that recombinant HSV1 vectors expressing Tat merit further investigation for their potential to prevent and/or contain HSV1 infection and dissemination.

Advances in pediatric asthma in 2013: coordinating asthma care

Last year's "Advances in pediatric asthma: moving toward asthma prevention" concluded that "We are well on our way to creating a pathway around wellness in asthma care and also to utilize new tools to predict the risk for asthma and take steps to not only prevent asthma exacerbations but also to prevent the early manifestations of the disease and thus prevent its evolution to severe asthma." This year's summary will focus on recent advances in pediatric asthma on prenatal and postnatal factors altering the natural history of asthma, assessment of asthma control, and new insights regarding potential therapeutic targets for altering the course of asthma in children, as indicated in Journal of Allergy and Clinical Immunology publications in 2013 and early 2014. Recent reports continue to shed light on methods to understand factors that influence the course of asthma, methods to assess and communicate levels of control, and new targets for intervention, as well as new immunomodulators. It will now be important to carefully assess risk factors for the development of asthma, as well as the risk for asthma exacerbations, and to improve the way we communicate this information in the health care system. This will allow parents, primary care physicians, specialists, and provider systems to more effectively intervene in altering the course of asthma and to further reduce asthma morbidity and mortality.

Herpesvirus-associated acute urticaria: an age matched case-control study

Background

Acute and recurrent acute urticaria are often associated with multiple factors including infections and recent data suggest a role for herpesviruses.

Objective

To test the null hypothesis, that is, there is no association of herpesvirus infections with urticaria.

Methods

Thirty-seven patients between one month and 15 years of age were age matched to 37 controls who were healthy or had mild acute respiratory infections but without urticaria. Patients and controls were followed for 1 to 6 years. Diagnostic studies included DNA detection by real-time PCR for herpes simplex virus (HSV) types 1 and 2, Epstein-Barr virus (EBV), cytomegalovirus (CMV) and human herpesvirus-6 (HHV-6). Tests for other infections included adenovirus, parvovirus B 19, respiratory syncytial virus, influenza A, Group A streptococci, rotavirus, and parasites.

Results

Specific infections were diagnosed in 26 of 37 cases and among 9 of 37 control children (P=0.0002). Single or concomitant herpesvirus infections occurred in 24 cases and in 4 controls (65% vs 11 %, p=0.0003). Cases had 10 HHV-6 infections, 8 CMV infections, 5 EBV infections, and 4 HSV-1 infections.

Conclusion

Herpesvirus infections are associated with acute or recurrent acute urticaria.