Herpesviruses: latency and reactivation - viral strategies and host response

Prevalence of human herpesvirus in plasma and saliva of cirrhotic patients: A pilot study

AIMS

The objective of this study was to identify the presence of human herpesvirus (HHV) in the plasma and saliva of hepatic-cirrhosis patients and correlate it with clinical data and laboratory tests. This is a pilot, observational, and cross-sectional study.

METHODS AND RESULTS

Specimens of plasma and saliva from 72 cirrhotic individuals were analyzed by means of polymerase chain reaction. The patient population had a mean age of 54.84 years old (SD ± 10) and was 70% males (51/72). Approximately 47% (n = 34) of the patients had leukopenia and HHV was not identified in the plasma specimens. The main species of HHV identified in the saliva were HHV-7 (n = 42, 62%) and Epstein-Barr virus (EBV) (n = 30, 41%). Moreover, there was a significant decrease in the total number of leukocytes and lymphocytes in saliva containing EBV (P = .038 and P = .047, respectively).

CONCLUSION

The results show that the presence of EBV in the saliva of cirrhotic patients was correlated with their circulating immune status. It may be possible that the immune dysfunction displayed by the cirrhotic patients plays a role in the shedding of EBV into saliva.

At Early Rheumatoid Arthritis Stage, the Infectious Spectrum Is Driven by Non-Familial Factors and Anti-CCP Immunization

Background/Objectives: Patients with rheumatoid arthritis (RA) are prone to develop infections. Methods: Accordingly, 195 untreated early (e)RA patients and 398 healthy controls were selected from women in Tatarstan's cohort to study infectious history in the anamnesis (four criteria) and in the previous year (16 criteria). Information about annual infections was collected face-to-face from year to year by a qualified rheumatologist/general practitioner and included the active use of information from medical records. Results: In the anamnesis, tuberculosis, and pneumonia, and in the previous year, respiratory tract infections, skin infections, and herpes simplex virus reactivation incidence were reported to be increased in eRA patients, as well as the event number and duration of acute and chronic tonsillitis. Moreover, more bacterial-suspected upper respiratory infections and urinary tract infections were retrieved in sporadic eRA patients as compared to familial eRA patients. An elevated immunization against CCP prevented respiratory tract infection in those with HSV exacerbation. Finally, associations were retrieved between infection (event number/delay) and RA indices: (i) chronic tonsillitis exacerbations with disease activity and health assessment (HAQ) in familial eRA; (ii) bacterial-suspected upper respiratory infections with the number of swollen and tender joints in sporadic eRA; and (iii) HSV exacerbation with inflammation in eRA patients with negative/low response against CCP. Here, we demonstrate the complex nature of the interplay of RA with specific infections. Conclusions: For the first time, differences in the patterns of annual trivial infections and their links with RA indices were found in cohorts of familial and sporadic cases of the disease. Additionally, for the first time, we identified a remarkable relationship between early RA and exacerbations of chronic tonsillitis, as well as tuberculosis in the patient's history. Altogether, this study supports the existence of a complex interplay between infections and RA at onset driven by familial status and the presence of anti-CCP Ab at elevated levels.

Mechanistic insights and emerging therapeutic stratagems for Alzheimer's disease

Alzheimer's disease (AD), a multi-factorial neurodegenerative disorder has affected over 30 million individuals globally and these numbers are expected to increase in the coming decades. Current therapeutic interventions are largely ineffective as they focus on a single target. Development of an effective drug therapy requires a deep understanding of the various factors influencing the onset and progression of the disease. Aging and genetic factors exert a major influence on the development of AD. Other factors like post-viral infections, iron overload, gut dysbiosis, and vascular dysfunction also exacerbate the onset and progression of AD. Further, post-translational modifications in tau, DRP1, CREB, and p65 proteins increase the disease severity through triggering mitochondrial dysfunction, synaptic loss, and differential interaction of amyloid beta with different receptors leading to impaired intracellular signalling. With advancements in neuroscience tools, new inter-relations that aggravate AD are being discovered including pre-existing diseases and exposure to other pathogens. Simultaneously, new therapeutic strategies involving modulation of gene expression through targeted delivery or modulation with light, harnessing the immune response to promote clearance of amyloid deposits, introduction of stem cells and extracellular vesicles to replace the destroyed neurons, exploring new therapeutic molecules from plant, marine and biological sources delivered in the free state or through nanoparticles and use of non-pharmacological interventions like music, transcranial stimulation and yoga. Polypharmacology approaches involving combination of therapeutic agents are also under active investigation for superior therapeutic outcomes. This review elaborates on various disease-causing factors, their underlying mechanisms, the inter-play between different disease-causing players, and emerging therapeutic options including those under clinical trials, for treatment of AD. The challenges involved in AD therapy and the way forward have also been discussed.

STINGing Defenses: Unmasking the Mechanisms of DNA Oncovirus-Mediated Immune Escape

DNA oncoviruses represent an intriguing subject due to their involvement in oncogenesis. These viruses have evolved mechanisms to manipulate the host immune response, facilitating their persistence and actively contributing to carcinogenic processes. This paper describes the complex interactions between DNA oncoviruses and the innate immune system, with a particular emphasis on the cGAS-STING pathway. Exploring these interactions highlights that DNA oncoviruses strategically target and subvert this pathway, exploiting its vulnerabilities for their own survival and proliferation within the host. Understanding these interactions lays the foundation for identifying potential therapeutic interventions. Herein, we sought to contribute to the ongoing efforts in advancing our understanding of the innate immune system in oncoviral pathogenesis.

Negative association between neurovascular coupling and cortical gray matter volume during the lifespan

Recent studies have established the moment-to-moment turnover of the blood-oxygen-level-dependent signal (TBOLD) at resting state as a key measure of local cortical brain function. Here, we sought to extend that line of research by evaluating TBOLD in 70 cortical areas with respect to corresponding brain volume, age, and sex across the lifespan in 1,344 healthy participants including 633 from the Human Connectome Project (HCP)-Development cohort (294 males and 339 females, age range 8-21 yr) and 711 healthy participants from HCP-Aging cohort (316 males and 395 females, 36-90 yr old). In both groups, we found that 1) TBOLD increased with age, 2) volume decreased with age, and 3) TBOLD and volume were highly significantly negatively correlated, independent of age. The inverse association between TBOLD and volume was documented in nearly all 70 brain areas and for both sexes, with slightly stronger associations documented for males. The strong correspondence between TBOLD and volume across age and sex suggests a common influence such as chronic neuroinflammation contributing to reduced cortical volume and increased TBOLD across the lifespan.NEW & NOTEWORTHY We report a significant negative association between resting functional magnetic resonance imaging (fMRI) blood-oxygen-level-dependent (BOLD) signal turnover (TBOLD) and cortical gray matter volume across the lifespan, such that TBOLD increased whereas volume decreased. We attribute this association to a hypothesized chronic, low-grade neuroinflammation, probably induced by various neurotropic pathogens, including human herpes viruses known to be dormant in the brain in a latent state and reactivated by stress, fever, and various environmental exposures, such as ultraviolet light.

Exploring Heparanase Levels in Tears: Insights From Herpes Simplex Virus-1 Keratitis Patients and Animal Studies

Purpose

Heparanase (HPSE) cleaves heparan sulfate proteoglycans during herpes simplex virus-1 (HSV-1) infection, aiding in viral egress and disease progression. Its action has been well established in in vitro and in vivo models, but its relevance in human patients remains unclear. This study aimed to specifically evaluate tear HPSE levels of patients with herpes simplex keratitis (HSK) and to correlate these findings with a commonly used murine model.

Methods

Tear samples from patient and mice samples were collected at LV Prasad Eye Institute, Hyderabad, India, and at the University of Illinois, Chicago, IL, respectively. Tears were collected from HSV-1 patients, bacterial/fungal keratitis cases, and healthy individuals. For in vivo study, C57BL/6 mice were infected with HSV-1 (McKrae strain) followed by tear fluid collection at various time points (0-10 days).

Results

The HSV-1, bacterial keratitis, fungal keratitis, and healthy control groups each had 30 patients. There was a significant difference in HPSE expression in the HSV-1 infected eyes (1.55 ± 0.19 units/mL) compared to HSV-1 contralateral eyes (1.23 ± 0.13 units/mL; P = 0.82), bacterial keratitis eyes (0.87 ± 0.15 units/mL; P = 0.0078), fungal keratitis eyes (0.64 ± 0.09 units/mL; P < 0.00001), and normal controls (0.53 ± 0.06 units/mL; P < 0.00001). C57BL/6 mice tear HPSE expression in infected eyes was 0.66 to 5.57 ng heparan sulfate (HS) removed per minute when compared to non-infected eye (range, 0.70-3.67 ng HS removed per minute).

Conclusions

To the best of our knowledge, this study is the first to report elevated HPSE levels in the tears of patients with different forms of HSV-1 keratitis, and it confirms similar findings in a murine model, providing a valuable basis for future in vivo and clinical research on HSV-1 ocular infection.

Development and evaluation of a time-resolved fluorescence labelled immunochromatographic strip assay for rapid and quantitative detection of bovine herpesvirus 1

Bovine herpes virus 1 (BoHV-1) causes a wide variety of diseases in wild and domestic cattle. The most widely used method for viral identification is real-time PCR, which can only be performed in laboratories using sophisticated instruments by expert personnel. Herein, we developed an ultrasensitive time-resolved fluorescence lateral flow immunochromatographic strip (ICS) assay for detecting BoHV-1 in bovine samples using a monoclonal antibody against BoHV-1 labelled with fluorescent microspheres, which can be applied in any setting. The intact process from sample collection to final result can be achieved in 15 min. The limit of detection of the assay for BoHV-1 was 102 TCID50/100 μL. The coincidence rate of the ICS method and real-time PCR recommended by the World Organization for Animal Health (WOAH) was 100% for negative, 92.30% for positive, and 95.42% for total, as evaluated by the detection of 131 clinical samples. This detection method was specifically targeted to BoHV-1, not exhibiting cross-reactivity with other bovine pathogens including BoHV-5. We developed an ICS assay equipped with a portable instrument that offers a sensitive and specific platform for the rapid and reliable detection of BoHV-1 in the field. The Point-of-Care test of BoHV-1 is suitable for the screening and surveillance of BoHV-1 in dairy herds.

Molecular and phylogenetic analysis of herpesviruses in endangered free-ranging cervids of Chile: ovine gammaherpesvirus-2-A novel threat to wild and domestic animal health in Chilean Patagonia

Introduction

Herpesvirus infections have been highlighted as emerging diseases affecting wildlife health and the conservation of several taxa. Malignant catarrhal fever (MCF) and infectious keratoconjunctivitis (IKC) are two viruses that infect wild ruminants. Nevertheless, epidemiological data on herpesviruses in South American wild ruminants are limited. An outbreak of caprine gammaherpesvirus-2 (CpHV-2) that recently was suspected as the cause of MCF in southern pudus (Pudu puda) prompted the need to conduct molecular screenings in Chilean cervids to understand the epidemiology of herpesviruses. The aim of this study was to determine the occurrence and genetic diversity of herpesviruses in free-ranging cervids from Chile.

Methods

Herpesvirus infection was assessed in antemortem blood samples (n = 86) from pudus (n = 81) and huemuls (Hippocamelus bisulcus) (n = 5), as well as postmortem samples of spleen (n = 24) and lung (n = 3) from pudus, using a nested pan-herpesvirus PCR assay.

Results

Combining all suitable sample types, DNA of pudu gammaherpesvirus-1 was detected in five pudues and five huemuls, with an overall prevalence of 9.90% (n = 10/101; 95% CI = 5.11-17.87%). One pudu tested positive for ovine gammaherpesvirus-2 (n = 1/96; 1.04%; 95% CI = 0.05-6.49%), and one pudu tested positive for a Macavirus sequence with 98.63 similarity to ovine gammaherpesvirus-2 (n = 96; 1.04%; 95% CI = 0.05-6.49%).

Discussion

To the best of our knowledge, this is the first report of a herpesvirus in huemul and of ovine gammaherpesvirus-2 in Chile. Our results also confirm the active circulation of herpesvirus in free-ranging cervids in Chilean Patagonia, and as such, MCF should be considered as a possible cause of disease in free-ranging Chilean pudus and livestock species. Further research is necessary to develop a plan of systematic monitoring (serological and pathological screening) of herpesviruses in Chilean wild and domestic ruminants to understand their diversity and impact on animal health and conservation.

Prevalence of Epstein Barr Virus and Herpes Simplex Virus Among Human Papillomavirus Negative Oral Cancer Patients: A Cross-Sectional Study from South India

The high incidence of oral carcinomas is due to its multifactorial etiology and the presence of various risk factors. Human Papillomavirus (HPV) has a proven role in the pathogenesis of oral carcinomas, but in the recent times there has been an increasing incidence of oral cancers who are negative for HPV infection. Also, these patients are non-smokers and non-drinkers so it could be speculated that these oral cancers are due to some other etiological factor probably of other viral infections. Therefore, this study examined the prevalence of Epstein Barr Virus (EBV) and Herpes Simplex Virus (HSV) among oral cancer patients. This cross-sectional study was conducted from January 2019 to June 2020. Biopsy samples from 47 newly diagnosed untreated patients with oral malignancies were collected along with their demographic and clinicopathological information. DNA extracted from the biopsies was processed for nested PCR for the detection of EBV and HSV. All the samples tested negative for HPV and HSV infection. Nested PCR detected 29 cases (70.7%) to be positive for EBV. The non-cancerous adjacent tissues also were negative for HPV, EBV and HSV. The prevalence of EBV was found to be more in males (62.1%) and the highest number of cases was of the left buccal mucosa compromising 34% of the total cases. From the present study it can be concluded that EBV but not HSV infection is associated with an increased risk of developing oral cancers. Although, 70.7% of the patients were found to be positive for EBV whether the viral infection played any role in the driving the malignancy needs to be further elucidated.

The potential role of ocular and otolaryngological mucus proteins in myalgic encephalomyelitis/chronic fatigue syndrome

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating illness associated with a constellation of other symptoms. While the most common symptom is unrelenting fatigue, many individuals also report suffering from rhinitis, dry eyes and a sore throat. Mucin proteins are responsible for contributing to the formation of mucosal membranes throughout the body. These mucosal pathways contribute to the body's defense mechanisms involving pathogenic onset. When compromised by pathogens the epithelium releases numerous cytokines and enters a prolonged state of inflammation to eradicate any particular infection. Based on genetic analysis, and computational theory and modeling we hypothesize that mucin protein dysfunction may contribute to ME/CFS symptoms due to the inability to form adequate mucosal layers throughout the body, especially in the ocular and otolaryngological pathways leading to low grade chronic inflammation and the exacerbation of symptoms.

Could Herpesviridae be the cause of severe acute hepatitis of unknown origin in children?

INTRODUCTION

Severe acute hepatitis (SAH) is defined by a severe inflammation of hepatocytes in the liver parenchyma which can lead to an acute liver failure, a clinical condition with high mortality rate that can be triggered by several factors but is usually associated to hepatotropic viruses' infection. In 2022, cases of children with severe acute hepatitis of unknown origin hospitalized in Glasgow, Scotland, were reported. Possible causes of this condition include, but are not limited to, undiagnosed viral (and non-viral) infections, autoimmune hepatitis, drug and/or chemical toxicity, mitochondrial chain respiratory and metabolic disorders.

AREAS COVERED

Herpesviruses can cause severe acute hepatitis, but little is known about the role and the mechanisms of herpesviruses as a causative agent of this type of hepatitis. We review the role of herpesviruses as causative agent of SAH in children and other possible mechanisms involved in this disease.

EXPERT OPINION

Differential diagnosis for herpesvirus in SAH should be implemented in all settings. Alternative fluids, such as saliva and dried blood, could be used in the diagnosis to overwhelm the availability of biological specimens at sufficient volume. In the future, genetic studies could also be added to increase the knowledge about severe acute hepatitis in children.

Associations of infections and vaccines with Alzheimer's disease point to a major role of compromised immunity rather than specific pathogen in AD

INTRODUCTION

Diverse pathogens (viral, bacterial, fungal) have been linked to Alzheimer's disease (AD) indicating a possibility that the culprit may be compromised immunity rather than particular microbe. If true, then vaccines with broad beneficial effects on immunity might be protective against AD.

METHODS

We estimated associations of common adult infections, including herpes simplex, zoster (shingles), pneumonia, and recurrent mycoses, as well as vaccinations against shingles and pneumonia, with the risk of AD in a pseudorandomized sample of the Health and Retirement Study.

RESULTS

Shingles, pneumonia, and mycoses diagnosed between ages 65-75, were all associated with higher risk of AD later in life, by 16%-42%. Pneumococcal and shingles vaccines received between ages 65-75 both lowered the risk of AD, by 15%-21%.

DISCUSSION

Our results support the idea that the connection between AD and infections involves compromised immunity rather than specific pathogen. We discuss mechanisms by which the declining immune surveillance may promote AD, and the role of biological aging in it. Repurposing of vaccines with broad beneficial effects on immunity could be a reasonable approach to AD prevention. Pneumococcal and zoster vaccines are promising candidates for such repurposing.

Perceived income inadequacy is associated with Epstein-Barr Virus latency and mental health outcomes in informal caregivers who are also employed in the healthcare industry

Finances are a prevalent source of stress. In a sample of 799 nursing home workers measured multiple times over 18 months, we found that higher perceived income inadequacy, the perception that one's expenses exceeds one's incomes, was associated with poorer self-reported mental health indicators and Epstein-Barr Virus antibody titers (a marker of cell-mediated immune function). Perceived income inadequacy predicted outcomes over and above the role of other socioeconomic status variables (objective household income and education). Mental health variables were not related to Epstein-Barr Virus antibody titers. Additionally, we found an interaction between perceived income inadequacy and informal caregiver status on our mental health outcomes; informal caregivers with higher perceived income inadequacy had poorer mental health than non-caregivers with the same perceived income inadequacy. Our findings may add nuance to the reserve capacity model, which states that those at lower socioeconomic levels are at higher risk of adverse health outcomes partly because they have fewer resources to address demands and strain. Perceived income inadequacy may significantly predict mental and physical well-being beyond other socioeconomic status variables, especially among lower-income employees. Caregiving stress and perceived income inadequacy may have synergistic effects on mental health.

Cell Intrinsic Determinants of Alpha Herpesvirus Latency and Pathogenesis in the Nervous System

Alpha herpesvirus infections (α-HVs) are widespread, affecting more than 70% of the adult human population. Typically, the infections start in the mucosal epithelia, from which the viral particles invade the axons of the peripheral nervous system. In the nuclei of the peripheral ganglia, α-HVs establish a lifelong latency and eventually undergo multiple reactivation cycles. Upon reactivation, viral progeny can move into the nerves, back out toward the periphery where they entered the organism, or they can move toward the central nervous system (CNS). This latency-reactivation cycle is remarkably well controlled by the intricate actions of the intrinsic and innate immune responses of the host, and finely counteracted by the viral proteins in an effort to co-exist in the population. If this yin-yang- or Nash-equilibrium-like balance state is broken due to immune suppression or genetic mutations in the host response factors particularly in the CNS, or the presence of other pathogenic stimuli, α-HV reactivations might lead to life-threatening pathologies. In this review, we will summarize the molecular virus-host interactions starting from mucosal epithelia infections leading to the establishment of latency in the PNS and to possible CNS invasion by α-HVs, highlighting the pathologies associated with uncontrolled virus replication in the NS.

The Quest for Immunity: Exploring Human Herpesviruses as Vaccine Vectors

Herpesviruses are large DNA viruses that have long been used as powerful gene therapy tools. In recent years, the ability of herpesviruses to stimulate both innate and adaptive immune responses has led to their transition to various applications as vaccine vectors. This vaccinology branch is growing at an unprecedented and accelerated rate. To date, human herpesvirus-based vectors have been used in vaccines to combat a variety of infectious agents, including the Ebola virus, foot and mouth disease virus, and human immunodeficiency viruses. Additionally, these vectors are being tested as potential vaccines for cancer-associated antigens. Thanks to advances in recombinant DNA technology, immunology, and genomics, numerous steps in vaccine development have been greatly improved. A better understanding of herpesvirus biology and the interactions between these viruses and the host cells will undoubtedly foster the use of herpesvirus-based vaccine vectors in clinical settings. To overcome the existing drawbacks of these vectors, ongoing research is needed to further advance our knowledge of herpesvirus biology and to develop safer and more effective vaccine vectors. Advanced molecular virology and cell biology techniques must be used to better understand the mechanisms by which herpesviruses manipulate host cells and how viral gene expression is regulated during infection. In this review, we cover the underlying molecular structure of herpesviruses and the strategies used to engineer their genomes to optimize capacity and efficacy as vaccine vectors. Also, we assess the available data on the successful application of herpesvirus-based vaccines for combating diseases such as viral infections and the potential drawbacks and alternative approaches to surmount them.

Latent human herpesvirus 6 is reactivated in CAR T cells

Cell therapies have yielded durable clinical benefits for patients with cancer, but the risks associated with the development of therapies from manipulated human cells are understudied. For example, we lack a comprehensive understanding of the mechanisms of toxicities observed in patients receiving T cell therapies, including recent reports of encephalitis caused by reactivation of human herpesvirus 6 (HHV-6)1. Here, through petabase-scale viral genomics mining, we examine the landscape of human latent viral reactivation and demonstrate that HHV-6B can become reactivated in cultures of human CD4+ T cells. Using single-cell sequencing, we identify a rare population of HHV-6 'super-expressors' (about 1 in 300-10,000 cells) that possess high viral transcriptional activity, among research-grade allogeneic chimeric antigen receptor (CAR) T cells. By analysing single-cell sequencing data from patients receiving cell therapy products that are approved by the US Food and Drug Administration2 or are in clinical studies3-5, we identify the presence of HHV-6-super-expressor CAR T cells in patients in vivo. Together, the findings of our study demonstrate the utility of comprehensive genomics analyses in implicating cell therapy products as a potential source contributing to the lytic HHV-6 infection that has been reported in clinical trials1,6-8 and may influence the design and production of autologous and allogeneic cell therapies.

Engineering siRNA therapeutics: challenges and strategies

Small interfering RNA (siRNA) is a potential method of gene silencing to target specific genes. Although the U.S. Food and Drug Administration (FDA) has approved multiple siRNA-based therapeutics, many biological barriers limit their use for treating diseases. Such limitations include challenges concerning systemic or local administration, short half-life, rapid clearance rates, nonspecific binding, cell membrane penetration inability, ineffective endosomal escape, pH sensitivity, endonuclease degradation, immunological responses, and intracellular trafficking. To overcome these barriers, various strategies have been developed to stabilize siRNA, ensuring their delivery to the target site. Chemical modifications implemented with nucleotides or the phosphate backbone can reduce off-target binding and immune stimulation. Encapsulation or formulation can protect siRNA from endonuclease degradation and enhance cellular uptake while promoting endosomal escape. Additionally, various techniques such as viral vectors, aptamers, cell-penetrating peptides, liposomes, and polymers have been developed for delivering siRNA, greatly improving their bioavailability and therapeutic potential.

Case Report: Recurrent Mpox in a Healthcare Worker in Nigeria

We report the first case of recurrent Mpox from Africa. The patient is a 36-year-old, previously healthy, HIV-negative male healthcare worker who developed two episodes of laboratory-confirmed Mpox in 2017 and 2018, 9 months apart. In both cases, he had prior close contact with confirmed Mpox cases in the hospital setting. On follow-up in 2022, he also reported recurrent postcoital skin eruptions over a previously healed genital scar from the first episode of Mpox. We highlight the need for future studies to investigate the true burden and risk factors for Mpox reinfection, relapse, and recrudescence.

Viral Encephalitis after Hematopoietic Cell Transplantation: A Systematic Review

Viral encephalitis is a rare but serious complication after hematopoietic cell transplantation (HCT). The nonspecific early signs and symptoms and rapid progression can make it difficult to diagnose and treat in a timely fashion. To better inform clinical decision making in post-HCT viral encephalitis, a systematic review of prior studies of viral encephalitis was performed, with the goal of characterizing the frequency of various infectious etiologies and their clinical course, including treatments and outcomes. A systematic review of studies of viral encephalitis was performed. Studies were included if they described a cohort of HCT recipients who were tested for at least 1 pathogen. Of 1613 unique articles initially identified, 68 met the inclusion criteria, with a total of 72,423 patients studied. A total of 778 cases of encephalitis were reported (1.1%). Human herpesvirus 6 (HHV-6) (n = 596), Epstein-Barr virus (n = 76), and cytomegalovirus (n = 33) were the most commonly reported causes of encephalitis, and HHV-6 encephalitis tended to occur the earliest, accounting for most cases prior to day +100 post-transplantation. Of 29,671 patients with available transplantation data, encephalitis was diagnosed in 282 of 4707 (6.0%) cord blood transplantation (CBT) recipients, in 372 of 24,664 (1.5%) non-CBT allogeneic HCT recipients, and in 5 of 300 (1.7%) autologous HCT recipients. Of the 282 CBT encephalitis cases, 270 (95.7%) were caused by HHV-6. Overall, 288 (37.0%) of the 778 patients with encephalitis died, and 75 deaths were attributable to encephalitis, with the time between diagnosis and death ranging from 3 to 192 days. Viral encephalitis occurs in approximately 1% of HCT recipients, and HHV-6 is the most common cause. Mortality following encephalitis in HCT recipients is high, indicating an urgent need for advancement in preventive and therapeutic strategies.

Differential diagnosis of fever and rash cases negative for measles and rubella to complement surveillance activities

In the quest to eliminate measles virus (MV) and rubella virus (Ruv), every suspected case must be properly identified and diagnosed. Since 2017, in Milan (Italy), a total of 978 measles and rubella suspected cases (fever and rash) were investigated and 310 were not laboratory confirmed (discarded cases). To improve surveillance activities, we investigated the presence in discarded cases of 8 other viral pathogens commonly associated with rash: human herpesvirus 6 (HHV-6) and 7 (HHV-7), parvovirus B19 (B19V), enterovirus (EV), Epstein-Barr virus (EBV), human adenovirus (HAdV), cytomegalovirus (HCMV), and SARS-CoV-2. Differential diagnosis was carried out on 289 discarded cases by multiplex real-time PCR assays. At least one pathogen was detected in 188 cases (65.1%) with HHV-7 being the most frequently detected virus. No difference in the number of detected infections overtime was observed and infections were identified in all age groups. As expected, most HHV-6, EV, HAdV, and HCMV-positive cases were found in children aged 0-4 years and HHV-7 was most frequent in the 15-39 age group. In light of the World Health Organization measles elimination goal, the introduction of laboratory methods for differential diagnosis is required for the final classification of clinically compatible cases. The used screening panel allowed us to increase the percentage of virus-positive cases to 87.5%, allowing us to clarify viral involvement and epidemiology, improve diagnosis, and strengthen surveillance activities. As all investigated pathogens were detected, this diagnostic panel was a suitable tool to complement MV and RuV surveillance activities.

Contribution of viral and bacterial infections to senescence and immunosenescence

Cellular senescence is a key biological process characterized by irreversible cell cycle arrest. The accumulation of senescent cells creates a pro-inflammatory environment that can negatively affect tissue functions and may promote the development of aging-related diseases. Typical biomarkers related to senescence include senescence-associated β-galactosidase activity, histone H2A.X phosphorylation at serine139 (γH2A.X), and senescence-associated heterochromatin foci (SAHF) with heterochromatin protein 1γ (HP-1γ protein) Moreover, immune cells undergoing senescence, which is known as immunosenescence, can affect innate and adaptative immune functions and may elicit detrimental effects over the host's susceptibility to infectious diseases. Although associations between senescence and pathogens have been reported, clear links between both, and the related molecular mechanisms involved remain to be determined. Furthermore, it remains to be determined whether infections effectively induce senescence, the impact of senescence and immunosenescence over infections, or if both events coincidently share common molecular markers, such as γH2A.X and p53. Here, we review and discuss the most recent reports that describe cellular hallmarks and biomarkers related to senescence in immune and non-immune cells in the context of infections, seeking to better understand their relationships. Related literature was searched in Pubmed and Google Scholar databases with search terms related to the sections and subsections of this review.

Viral skin diseases in odontocete cetaceans: gross, histopathological, and molecular characterization of selected pathogens

Fifty-five skin lesions from 31 stranded cetaceans along the Canary coasts (2011-2021) were submitted to macroscopic, histological, and molecular analyses to confirm infection by cetacean poxvirus, herpesvirus and cetacean morbillivirus. They were macroscopically categorized into eight categories with respective subcategories according to their color, shape, size, and consistency. Cetacean poxvirus was detected in 54.54% of the skin lesions through real-time and conventional PCRs based on the DNA polymerase gene. Additionally, herpesvirus and morbillivirus were currently detected from 43.63 and 1.82% of the cutaneous lesions, respectively. Coinfection of poxvirus and herpesvirus was detected in nine of them (16.36%), which makes the present study the first to report coinfection by both pathogens in skin lesions in cetaceans. A plausible approach to histopathological characterization of poxvirus-and herpesvirus-positive skin lesions was established. Hyperkeratosis, acanthosis, ballooning degeneration, and intracytoplasmic inclusion bodies in vacuolized keratinocytes through the stratum spinosum were common findings in poxvirus skin lesions. Alphaherpesvirus was associated with a prominent acanthotic epidermis, moderate necrosis, multifocal dyskeratosis, and irregular keratinocytes with both cellular and nuclei pleomorphism. The common histopathological findings of both pathogens were observed in coinfection lesions. However, those associated with herpesvirus were considerably more remarkable. Relationships between molecular and microscopic findings were observed for the lesions that showed tattoo-like and tortuous patterns. Further multidisciplinary diagnostic studies of infected skin lesions are needed to understand the epidemiology of these emerging infectious diseases.

Mechanistic insights into the role of herpes simplex virus 1 in Alzheimer's disease

Alzheimer's Disease (AD) is an aging-associated neurodegenerative disorder, threatening millions of people worldwide. The onset and progression of AD can be accelerated by environmental risk factors, such as bacterial and viral infections. Human herpesviruses are ubiquitous infectious agents that underpin numerous inflammatory disorders including neurodegenerative diseases. Published studies concerning human herpesviruses in AD imply an active role HSV-1 in the pathogenesis of AD. This review will summarize the current understanding of HSV-1 infection in AD and highlight some barriers to advance this emerging field.

Association of chronic periodontitis with multiple sclerosis: A systematic review and meta-analysis

BACKGROUND

Chronic periodontitis (CP) is a multifactorial, chronic inflammatory disease of microbial etiology that manifests as a result of the dysfunction of the immune mechanism, culminating in the destruction of the alveolar bone of the jaws. Multiple sclerosis (MS) is an autoimmune disorder that affects the central nervous system (CNS), leads to demyelination and degeneration of nerve axons and often causes severe physical and/or cognitive impairment. As CP and MS involve inflammatory mechanisms and immune dysfunction, researchers have attempted to study the association between them.

AIM

To systematically review the literature on the epidemiological association between CP and MS in adults.

METHODS

PRISMA 2020 statement was used in the study protocol. The design was done according to the Cochrane methodology. A comprehensive literature search was performed in PubMed, Scopus and Cochrane databases; a manual search and evaluation of the gray literature was also performed. The meta-analysis was performed by Review Manager (RevMan) 5.4. Odds ratio (OR) with 95% confidence interval (CI) was defined as the effect size of the outcome. Heterogeneity was assessed by Chi-square and I2. The articles evaluated were written in English, without a time limit, concern observational studies (patient-controls) and report the diagnostic criteria of the diseases. Duplicate entries were excluded. To evaluate the reliability of the results of each study, Newcastle-Ottawa Scale (NOS) and GRADE tools were used. Two independent reviewers did all evaluations with a resolution of discrepancies by a third.

RESULTS

Meta-analysis included three observation studies examined 3376 people. MS patients are significantly more likely to be diagnosed with CP than healthy controls (OR 1.93, 95% CI 1.54-2.42, p<0.0001).

CONCLUSION

A high prevalence of CP was found among MS patients compared with healthy controls. Healthcare professionals should be aware of the association between these pathological entities to provide patients with high-quality care through an effective and holistic diagnostic and therapeutic approach.

The Impact of Co-Infections for Human Gammaherpesvirus Infection and Associated Pathologies

The two oncogenic human gammaherpesviruses Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) cause significant disease burden, particularly in immunosuppressed individuals. Both viruses display latent and lytic phases of their life cycle with different outcomes for their associated pathologies. The high prevalence of infectious diseases in Sub-Saharan Africa (SSA), particularly HIV/AIDS, tuberculosis, malaria, and more recently, COVID-19, as well as their associated inflammatory responses, could potentially impact either virus' infectious course. However, acute or lytically active EBV and/or KSHV infections often present with symptoms mimicking these predominant diseases leading to misdiagnosis or underdiagnosis of oncogenic herpesvirus-associated pathologies. EBV and/or KSHV infections are generally acquired early in life and remain latent until lytic reactivation is triggered by various stimuli. This review summarizes known associations between infectious agents prevalent in SSA and underlying EBV and/or KSHV infection. While presenting an overview of both viruses' biphasic life cycles, this review aims to highlight the importance of co-infections in the correct identification of risk factors for and diagnoses of EBV- and/or KSHV-associated pathologies, particularly in SSA, where both oncogenic herpesviruses as well as other infectious agents are highly pervasive and can lead to substantial morbidity and mortality.

Disrupting Kaposi's Sarcoma-Associated Herpesvirus (KSHV) Latent Replication with a Small Molecule Inhibitor

Kaposi's sarcoma-associated herpesvirus (KSHV) can establish latent lifelong infections in infected individuals. During viral latency, the latency-associated nuclear antigen (LANA) mediates the replication of the latent viral genome in dividing cells and tethers them to mitotic chromosomes, thus ensuring their partitioning into daughter cells during mitosis. This study aims to inhibit Kaposi's sarcoma-associated herpesvirus (KSHV) latent replication by targeting the LANA-DNA interaction using small molecular entities. Drawing from first-generation inhibitors and using growth vectors identified through STD-NMR, we expanded these compounds using Suzuki-Miyaura cross-coupling. This led to a deeper understanding of SAR achieved by microscale thermophoresis (MST) measurements and cell-free tests via electrophoretic mobility shift assays (EMSA). Our most potent compounds successfully inhibit LANA-mediated replication in cell-based assays and demonstrate favorable in vitro ADMET-profiles, including suitable metabolic stability, Caco-2 permeability, and cytotoxicity. These compounds could serve as qualified leads for the future refinement of small molecule inhibitors of KSHV latent replication.

Herpesviruses reactivation following COVID-19 vaccination: a systematic review and meta-analysis

BACKGROUND

The reactivation of herpesviruses (HHV) in COVID-19 patients is evident in the literature. Several reports have been published regarding the reactivation of these viruses (HSV, VZV, EBV, and CMV) among those who got COVID-19 vaccines. In this study, we aimed to review the current evidence to assess whether HHVs reactivation has any association with the prior administration of COVID-19 vaccines.

METHODS

A systematic search was conducted on 25 September 2022 in PubMed/MEDLINE, Web of Science, and EMBASE. We included all observational studies, case reports, and case series which reported the reactivation of human herpesviruses following administration of COVID-19 vaccines.

RESULTS

Our systematic search showed 80 articles that meet the eligibility criteria. Among the evaluated COVID-19 vaccines, most of the vaccines were mRNA based. Evidence from observational studies showed the possible relation between COVID-19 vaccine administration and VZV and HSV reactivation. The results of our proportion meta-analysis showed that the rate of VZV reactivation among those who received the COVID-19 vaccine was 14 persons per 1000 vaccinations (95% CI 2.97-32.80). Moreover, our meta-analysis for HSV reactivation showed the rate of 16 persons per 1000 vaccinations (95% CI 1.06-46.4). Furthermore, the evidence from case reports/series showed 149 cases of HHV reactivation. There were several vaccines that caused reactivation including BNT162b2 mRNA or Pfizer-BioNTech (n = 76), Oxford-AstraZeneca (n = 22), mRNA-1273 or Moderna (n = 17), Sinovac (n = 4), BBIBP-CorV or Sinopharm (n = 3), Covaxin (n = 3), Covishield (n = 3), and Johnson and Johnson (n = 1). Reactivated HHVs included varicella-zoster virus (VZV) (n = 114), cytomegalovirus (CMV) (n = 15), herpes simplex virus (HSV) (n = 14), Epstein-Barr virus (EBV) (n = 6), and HHV-6 (n = 2). Most cases reported their disease after the first dose of the vaccine. Many patients reported having comorbidities, of which hypertension, diabetes mellitus, dyslipidemia, chicken pox, and atrial fibrillation were common.

CONCLUSION

In conclusion, our study showed the possible association between COVID-19 vaccination and herpesvirus reactivation. The evidence for VZV and HSV was supported by observational studies. However, regarding other herpesviruses (EBV and CMV), further research especially from observational studies and clinical trials is required to elucidate the interaction between COVID-19 vaccination and their reactivation.

Instantaneous Inactivation of Herpes Simplex Virus by Silicon Nitride Bioceramics

Hydrolytic reactions taking place at the surface of a silicon nitride (Si3N4) bioceramic were found to induce instantaneous inactivation of Human herpesvirus 1 (HHV-1, also known as Herpes simplex virus 1 or HSV-1). Si3N4 is a non-oxide ceramic compound with strong antibacterial and antiviral properties that has been proven safe for human cells. HSV-1 is a double-stranded DNA virus that infects a variety of host tissues through a lytic and latent cycle. Real-time reverse transcription (RT)-polymerase chain reaction (PCR) tests of HSV-1 DNA after instantaneous contact with Si3N4 showed that ammonia and its nitrogen radical byproducts, produced upon Si3N4 hydrolysis, directly reacted with viral proteins and fragmented the virus DNA, irreversibly damaging its structure. A comparison carried out upon testing HSV-1 against ZrO2 particles under identical experimental conditions showed a significantly weaker (but not null) antiviral effect, which was attributed to oxygen radical influence. The results of this study extend the effectiveness of Si3N4's antiviral properties beyond their previously proven efficacy against a large variety of single-stranded enveloped and non-enveloped RNA viruses. Possible applications include the development of antiviral creams or gels and oral rinses to exploit an extremely efficient, localized, and instantaneous viral reduction by means of a safe and more effective alternative to conventional antiviral creams. Upon incorporating a minor fraction of micrometric Si3N4 particles into polymeric matrices, antiherpetic devices could be fabricated, which would effectively impede viral reactivation and enable high local effectiveness for extended periods of time.

The Diagnosis and Management of Herpes Simplex Pneumonia in the Critical Care Setting: A Comprehensive Review

Herpes simplex virus (HSV) belongs to the Herpesviridae family and is divided into two subtypes: HSV-1 and HSV-2. It is known that herpesviruses lie dormant in neural ganglion cells and are reactivated during times of stress, trauma, fever, and immunosuppression. While HSV primarily causes mucosal infections such as cold sores or upper respiratory tract manifestations, it can also lead to serious, life-threatening infections, particularly in immunocompromised patients. Although HSV is occasionally detected in airway samples from critically ill patients, true HSV pneumonia is rare. HSV pneumonia is thought to result from the aspiration of salivary secretions that can travel from the pharynx and tracheobronchial areas to the lungs. It can be difficult to diagnose, and the presence of HSV in respiratory specimens does not necessarily indicate true infection. Treatment with antiviral drugs such as acyclovir should be considered based on the clinical presentation, corroborative findings, and the presence of cytopathological changes in the bronchoalveolar specimen. The prognosis of HSV pneumonia is generally poor and early detection is critical for better outcomes. This review discusses the risk factors, clinical presentation, diagnosis, treatment, and prognosis of HSV pneumonia and emphasizes the importance of distinguishing between true infection and carrier status.

The Potential Role of Ocular and Otolaryngological Mucus Proteins in Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating illness associated with a constellation of other symptoms. While the most common symptom is unrelenting fatigue, many individuals also report suffering from rhinitis, dry eyes and a sore throat. Mucin proteins are responsible for contributing to the formation of mucosal membranes throughout the body. These mucosal pathways contribute to the body's defense mechanisms involving pathogenic onset. When compromised by pathogens the epithelium releases numerous cytokines and enters a prolonged state of inflammation to eradicate any particular infection. Based on genetic analysis, and computational theory and modeling we hypothesize that mucin protein dysfunction may contribute to ME/CFS symptoms due to the inability to form adequate mucosal layers throughout the body, especially in the ocular and otolaryngological pathways leading to low grade chronic inflammation and the exacerbation of symptoms.

miRNAs in Neurological Manifestation in Patients Co-Infected with SARS-CoV-2 and Herpesvírus 6 (HHV-6)

Human herpesviruses (HHVs) can establish latency and be reactivated, also are neurotropic viruses that can trigger neurological disorders. HHV-6 is a herpesvirus that is associated with neurological disorders. Studies have reported the detection of HHV-6 in patients with COVID-19 and neurological manifestations. However, specific diagnoses of the neurological disorders caused by these viruses tend to be invasive or difficult to interpret. This study aimed to establish a relationship between miRNA and neurological manifestations in patients co-infected with COVID-19 and HHV-6 and evaluate miRNAs as potential biomarkers. Serum samples from COVID-19 patients in the three cohorts were analyzed. miRNA analysis by real-time polymerase chain reaction (qPCR) revealed miRNAs associated with neuroinflammation were highly expressed in patients with neurological disorders and HHV-6 detection. When compared with the group of patients without detection of HHVs DNA and without neurological alterations, the group with detection of HHV-6 DNA and neurological alteration, displayed significant differences in the expression of mir-21, mir-146a, miR-155 and miR-let-7b (p < 0.01). Our results reinforce the involvement of miRNAs in neurological disorders and provide insights into their use as biomarkers for neurological disorders triggered by HHV-6. Furthermore, understanding the expression of miRNAs may contribute to therapeutic strategies.

Depleting CD103+ resident memory T cells in vivo reveals immunostimulatory functions in oral mucosa

The oral mucosa is a frontline for microbial exposure and juxtaposes several unique tissues and mechanical structures. Based on parabiotic surgery of mice receiving systemic viral infections or co-housing with microbially diverse pet shop mice, we report that the oral mucosa harbors CD8+ CD103+ resident memory T cells (TRM), which locally survey tissues without recirculating. Oral antigen re-encounter during the effector phase of immune responses potentiated TRM establishment within tongue, gums, palate, and cheek. Upon reactivation, oral TRM triggered changes in somatosensory and innate immune gene expression. We developed in vivo methods for depleting CD103+ TRM while sparing CD103neg TRM and recirculating cells. This revealed that CD103+ TRM were responsible for inducing local gene expression changes. Oral TRM putatively protected against local viral infection. This study provides methods for generating, assessing, and in vivo depleting oral TRM, documents their distribution throughout the oral mucosa, and provides evidence that TRM confer protection and trigger responses in oral physiology and innate immunity.

Viruses - a major cause of amyloid deposition in the brain

INTRODUCTION

Clinically, Alzheimer's disease (AD) is a syndrome with a spectrum of various cognitive disorders. There is a complete dissociation between the pathology and the clinical presentation. Therefore, we need a disruptive new approach to be able to prevent and treat AD.

AREAS COVERED

In this review, the authors extensively discuss the evidence why the amyloid beta is not the pathological cause of AD which makes therefore the amyloid hypothesis not sustainable anymore. They review the experimental evidence underlying the role of microbes, especially that of viruses, as a trigger/cause for the production of amyloid beta leading to the establishment of a chronic neuroinflammation as the mediator manifesting decades later by AD as a clinical spectrum. In this context, the emergence and consequences of the infection/antimicrobial protection hypothesis are described. The epidemiological and clinical data supporting this hypothesis are also analyzed.

EXPERT OPINION

For decades, we have known that viruses are involved in the pathogenesis of AD. This discovery was ignored and discarded for a long time. Now we should accept this fact, which is not a hypothesis anymore, and stimulate the research community to come up with new ideas, new treatments, and new concepts.

Molecular Pathogenesis of Human Immunodeficiency Virus-Associated Disease of Oropharyngeal Mucosal Epithelium

The oropharyngeal mucosal epithelia have a polarized organization, which is critical for maintaining a highly efficient barrier as well as innate immune functions. In human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) disease, the barrier and innate immune functions of the oral mucosa are impaired via a number of mechanisms. The goal of this review was to discuss the molecular mechanisms of HIV/AIDS-associated changes in the oropharyngeal mucosa and their role in promoting HIV transmission and disease pathogenesis, notably the development of opportunistic infections, including human cytomegalovirus, herpes simplex virus, and Epstein-Barr virus. In addition, the significance of adult and newborn/infant oral mucosa in HIV resistance and transmission was analyzed. HIV/AIDS-associated changes in the oropharyngeal mucosal epithelium and their role in promoting human papillomavirus-positive and negative neoplastic malignancy are also discussed.

Pathophysiology of reinfection by exogenous HSV-1 is driven by heparanase dysfunction

Limited knowledge exists on exogenous DNA virus reinfections. Herpes simplex virus-1 (HSV-1), a prototype DNA virus, causes multiple human diseases including vision-threatening eye infections. While reinfection with an exogenous HSV-1 strain is considered plausible, little is known about the underlying mechanisms governing its pathophysiology in a host. Heparanase (HPSE), a host endoglycosidase, when up-regulated by HSV-1 infection dictates local inflammatory response by destabilizing tissue architecture. Here, we demonstrate that HSV-1 reinfection in mice causes notable pathophysiology in wild-type controls compared to the animals lacking HPSE. The endoglycosidase promotes infected cell survival and supports a pro-disease environment. In contrast, lack of HPSE strengthens intrinsic immunity by promoting cytokine expression, inducing necroptosis of infected cells, and decreasing leukocyte infiltration into the cornea. Collectively, we report that immunity from a recent prior infection fails to abolish disease manifestation during HSV-1 reinfection unless HPSE is rendered inactive.

Viral reactivations and co-infections in COVID-19 patients: a systematic review

BACKGROUND

Viral reactivations and co-infections have been reported among COVID-19 patients. However, studies on the clinical outcomes of different viral reactivations and co-infections are currently in limit. Thus, the primary purpose of this review is to perform an overarching investigation on the cases of latent virus reactivation and co-infection in COVID-19 patients to build collective evidence contributing to improving patient health. The aim of the study was to conduct a literature review to compare the patient characteristics and outcomes of reactivations and co-infections of different viruses.

METHODS

Our population of interest included confirmed COVID-19 patients who were diagnosed with a viral infection either concurrently or following their COVID-19 diagnosis. We extracted the relevant literature through a systematic search using the key terms in the online databases including the EMBASE, MEDLINE, Latin American Caribbean Health Sciences Literature (LILACS), from inception onwards up to June 2022. The authors independently extracted data from eligible studies and assessed the risk of bias using the Consensus-based Clinical Case Reporting (CARE) guidelines and the Newcastle-Ottawa Scale (NOS). Main patient characteristics, frequency of each manifestation, and diagnostic criteria used in studies were summarized in tables.

RESULTS

In total, 53 articles were included in this review. We identified 40 reactivation studies, 8 coinfection studies, and 5 studies where concomitant infection in COVID-19 patients was not distinguished as either reactivation or coinfection. Data were extracted for 12 viruses including IAV, IBV, EBV, CMV, VZV, HHV-1, HHV-2, HHV-6, HHV-7, HHV-8, HBV, and Parvovirus B19. EBV, HHV-1, and CMV were most frequently observed within the reactivation cohort, whereas IAV and EBV within the coinfection cohort. In both reactivation and coinfection groups, patients reported cardiovascular disease, diabetes, and immunosuppression as comorbidities, acute kidney injury as complication, and lymphopenia and elevated D-dimer and CRP levels from blood tests. Common pharmaceutical interventions in two groups included steroids and antivirals.

CONCLUSION

Overall, these findings expand our knowledge on the characteristics of COVID-19 patients with viral reactivations and co-infections. Our experience with current review indicates a need for further investigations on virus reactivation and coinfection among COVID-19 patients.

Relationships Between Stress-Responsive Biomarkers, ART Adherence, and Viral Suppression Among Adolescent Girls and Young Women Living With HIV in South Africa: An HPTN 068 Analysis

BACKGROUND

Adolescent girls and young women (AGYW) living with HIV who have higher stress levels may be at risk of stress-related biological alterations, which could influence HIV progression and adherence to antiretroviral therapy (ART).

SETTING

We aimed to estimate associations among stress-responsive biomarkers, ART adherence, and viral suppression in AGYW living with HIV in South Africa. We also hypothesized that psychosocial stressors [eg, depression, food insecurity, low socioeconomic status (SES), and HSV-2] would be associated with higher biomarker levels.

METHODS

We used 2018/2019 data from the HIV Prevention Trials Network 068 cohort to assess associations between stress-responsive biomarkers and viral suppression (<1000 copies/mL) and ART adherence measured using dried blood spot cards. Stress-responsive biomarkers included C-reactive protein, herpes simplex virus type 1, and cytomegalovirus infection and reactivation. Associations were estimated using unadjusted log-binomial or ordinal logistic regression models.

RESULTS

In 166 AGYW living with HIV, there was no association between stress-responsive biomarkers and viral suppression or ART adherence. However, increased C-reactive protein levels were associated with higher HSV-2 infection [odds ratio (OR) 1.98; 95% confidence interval (CI) 1.11, 3.52], being a government grant recipient (OR 3.21; 95% CI: 1.30, 7.92), lower food insecurity (OR 0.34; 95% CI: 0.13, 0.90), and increased body mass index (OR 1.07; 95% CI: 1.01, 1.14).

CONCLUSIONS

High prevalence of psychosocial stressors and persistent herpesviruses in AGYW living with HIV has the potential to lead to poorer health outcomes. More research is needed to untangle relationships between economic stability, chronic disease, and chronic stress.

Susceptibility and Permissivity of Zebrafish (Danio rerio) Larvae to Cypriniviruses

The zebrafish (Danio rerio) represents an increasingly important model organism in virology. We evaluated its utility in the study of economically important viruses from the genus Cyprinivirus (anguillid herpesvirus 1, cyprinid herpesvirus 2 and cyprinid herpesvirus 3 (CyHV-3)). This revealed that zebrafish larvae were not susceptible to these viruses after immersion in contaminated water, but that infections could be established using artificial infection models in vitro (zebrafish cell lines) and in vivo (microinjection of larvae). However, infections were transient, with rapid viral clearance associated with apoptosis-like death of infected cells. Transcriptomic analysis of CyHV-3-infected larvae revealed upregulation of interferon-stimulated genes, in particular those encoding nucleic acid sensors, mediators of programmed cell death and related genes. It was notable that uncharacterized non-coding RNA genes and retrotransposons were also among those most upregulated. CRISPR/Cas9 knockout of the zebrafish gene encoding protein kinase R (PKR) and a related gene encoding a protein kinase containing Z-DNA binding domains (PKZ) had no impact on CyHV-3 clearance in larvae. Our study strongly supports the importance of innate immunity-virus interactions in the adaptation of cypriniviruses to their natural hosts. It also highlights the potential of the CyHV-3-zebrafish model, versus the CyHV-3-carp model, for study of these interactions.

Inferring the disruption of rabies circulation in vampire bat populations using a betaherpesvirus-vectored transmissible vaccine

Transmissible vaccines are an emerging biotechnology that hold prospects to eliminate pathogens from wildlife populations. Such vaccines would genetically modify naturally occurring, nonpathogenic viruses ("viral vectors") to express pathogen antigens while retaining their capacity to transmit. The epidemiology of candidate viral vectors within the target wildlife population has been notoriously challenging to resolve but underpins the selection of effective vectors prior to major investments in vaccine development. Here, we used spatiotemporally replicated deep sequencing to parameterize competing epidemiological mechanistic models of Desmodus rotundus betaherpesvirus (DrBHV), a proposed vector for a transmissible vaccine targeting vampire bat-transmitted rabies. Using 36 strain- and location-specific time series of prevalence collected over 6 y, we found that lifelong infections with cycles of latency and reactivation, combined with a high R0 (6.9; CI: 4.39 to 7.85), are necessary to explain patterns of DrBHV infection observed in wild bats. These epidemiological properties suggest that DrBHV may be suited to vector a lifelong, self-boosting, and transmissible vaccine. Simulations showed that inoculating a single bat with a DrBHV-vectored rabies vaccine could immunize >80% of a bat population, reducing the size, frequency, and duration of rabies outbreaks by 50 to 95%. Gradual loss of infectious vaccine from vaccinated individuals is expected but can be countered by inoculating larger but practically achievable proportions of bat populations. Parameterizing epidemiological models using accessible genomic data brings transmissible vaccines one step closer to implementation.

Manipulation of Oxidative Stress Responses by Non-Thermal Plasma to Treat Herpes Simplex Virus Type 1 Infection and Disease

Herpes simplex virus type 1 (HSV-1) is a contagious pathogen with a large global footprint, due to its ability to cause lifelong infection in patients. Current antiviral therapies are effective in limiting viral replication in the epithelial cells to alleviate clinical symptoms, but ineffective in eliminating latent viral reservoirs in neurons. Much of HSV-1 pathogenesis is dependent on its ability to manipulate oxidative stress responses to craft a cellular environment that favors HSV-1 replication. However, to maintain redox homeostasis and to promote antiviral immune responses, the infected cell can upregulate reactive oxygen and nitrogen species (RONS) while having a tight control on antioxidant concentrations to prevent cellular damage. Non-thermal plasma (NTP), which we propose as a potential therapy alternative directed against HSV-1 infection, is a means to deliver RONS that affect redox homeostasis in the infected cell. This review emphasizes how NTP can be an effective therapy for HSV-1 infections through the direct antiviral activity of RONS and via immunomodulatory changes in the infected cells that will stimulate anti-HSV-1 adaptive immune responses. Overall, NTP application can control HSV-1 replication and address the challenges of latency by decreasing the size of the viral reservoir in the nervous system.

Inborn Errors of Immunity Predisposing to Herpes Simplex Virus Infections of the Central Nervous System

Herpesvirus infections can lead to a number of severe clinical manifestations, particularly when involving the central nervous system (CNS), causing encephalitis and meningitis. However, understanding of the host factors conferring increased susceptibility to these diseases and their complications remains incomplete. Previous studies have uncovered defects in the innate Toll-like receptor 3 pathway and production of type I interferon (IFN-I) in children and adults that predispose them to herpes simplex encephalitis. More recently, there is accumulating evidence for an important role of IFN-independent cell-autonomous intrinsic mechanisms, including small nucleolar RNAs, RNA lariat metabolism, and autophagy, in restricting herpesvirus replication and conferring protection against CNS infection. The present review first describes clinical manifestations of HSV infection with a focus on neurological complications and then summarizes the host-pathogen interactions and innate immune pathways responsible for sensing herpesviruses and triggering antiviral responses and immunity. Next, we review the current landscape of inborn errors of immunity and the underlying genetic defects and disturbances of cellular immune pathways that confer increased susceptibility to HSV infection in CNS. Ultimately, we discuss some of the present outstanding unanswered questions relating to inborn errors of immunity and HSV CNS infection together with some perspectives and future directions for research in the pathogenesis of these severe diseases in humans.

The emerging mechanism behind viral infections and extracellular vesicles hypotheses leading to neuroinflammation and Alzheimer's disease pathology

Despite decades of repeated and intense research, the etiology of sudden Alzheimer's disease (AD) symptoms is still unclear. AD progressive pathology mainly involves neuron damage, depositions of amyloid-beta (Aβ), and hyperphosphorylated tau protein. All these defects are manifested by exaggerated cytokine storm and neuroinflammation leading to irreversible brain damage in the long term. Despite the numerous risks and drawbacks associated with AD, it is believed that there is a hidden unknown causative and predisposing factors for AD. Extracellular vesicles (EVs) are small vesicles released by cells as a type of intercellular communication. Several pieces of evidence support the inclusion of viral components within EVs facilitating their penetration into the blood-brain barrier leading to neuroinflammation. In light of the SARS-CoV-19 pandemic and its related neurological complications, it is mandatory to highlight the possibility and viability of viral infections such as varicella-zoster virus (VZV) and herpes simplex virus (HSV) on the onset of AD. Herein, the author is investigating the potential role of VZV and HSV along with highlighting the suggested route of pathogenesis entry resulting in AD manifestations. Additionally, this review aims to summarize the role of EVs in mediating the central nervous system viral infections leading to AD.

Insights into the Novel Therapeutics and Vaccines against Herpes Simplex Virus

Herpes simplex virus (HSV) is a great concern of the global health community due to its linked infection of inconspicuous nature and resultant serious medical consequences. Seropositive patients may develop ocular disease or genital herpes as characteristic infectious outcomes. Moreover, the infectious nature of HSV is so complex that the available therapeutic options have been modified in certain ways to cure it. However, no permanent and highly effective cure has been discovered. This review generates insights into the available prophylactic and therapeutic interventions against HSV. A methodological research approach is used for study design and data complication. Only the latest data from publications are acquired to shed light on updated therapeutic approaches. These studies indicate that the current antiviral therapeutics can suppress the symptoms and control viral transmission up to a certain level, but cannot eradicate the natural HSV infection and latency outcomes. Most trials that have entered the clinical phase are made part of this review to understand what is new within the field. Some vaccination approaches are also discussed. Moreover, some novel therapeutic options that are currently in research annals are given due consideration for future development. The data can enable the scientific community to direct their efforts to fill the gaps that remain unfilled in terms of therapies for HSV. The need is to integrate scientific efforts to produce a proper cure against HSV to control the virus spread, resistance, and mutation in future disease management.

A Comprehensive Overview of Epidemiology, Pathogenesis and the Management of Herpes Labialis

Herpes labialis remains exceedingly prevalent and is one of the most common human viral infections throughout the world. Recurrent herpes labialis evolves from the initial viral infection by herpes simplex virus type 1 (HSV-1) which subsequently presents with or without symptoms. Reactivation of this virus is triggered by psychosocial factors such as stress, febrile environment, ultraviolet light susceptibility, or specific dietary inadequacy. This virus infection is also characterized by uninterrupted transitions between chronic-latent and acute-recurrent phases, allowing the virus to opportunistically avoid immunity and warrant the transmission to other vulnerable hosts simultaneously. This review comprehensively evaluates the current evidence on epidemiology, pathogenesis, transmission modes, clinical manifestations, and current management options of herpes labialis infections.

Seasonal variation of cytomegalovirus disease in kidney transplant recipients

PURPOSE

Studies conducted in the northern United States found cytomegalovirus (CMV) disease after liver transplantation follows a seasonal pattern, with increased incidence in fall and winter. This has not been evaluated in kidney transplant recipients. Improved understanding of CMV seasonality may help guide use of preventative therapies.

METHODS

We evaluated adult patients receiving a kidney transplant at our center in Wisconsin from January 1, 1995 to December 31, 2018. CMV event was defined as quantifiable viral replication with clinical signs or symptoms suspicious for CMV per current consensus recommendations. Seasons were divided as follows: winter (December-February), spring (March-May), summer (June-August), and fall (September-November). The primary objective was to evaluate the annual distribution of CMV disease and determine whether this differed by season.

RESULTS

There were 6151 kidney transplants in the study period. A total of 913 patients had 1492 episodes of CMV. Median time from transplant to first detection was 5.51 months (interquartile range [IQR] 2.87-11.7). The observed overall incidence exceeded the expected incidence in winter (+.7%), spring (+5.5%), and fall (+3.4%) and was less than expected in summer (-9.5%) (p = .18). The incidence of CMV during summer, however, was 21% less than expected (p = .001) in recipients who were CMV positive (R+) at the time of transplantation. No such difference was observed in CMV negative recipients (R-; p = .58).

CONCLUSION

CMV after kidney transplant appears to be less common during the summer season in patients who were R+ at transplant but does not follow seasonal variation in R-. Reasons for this are unclear but are likely related to CMV-specific cell-mediated immunity. These findings may have clinical implications, particularly the use of non-pharmacologic strategies to improve response to antiviral therapy.

Family Herpesviridae and neuroinfections: current status and research in progress

This article addresses the relationship between human herpesviruses (HHVs) and neuroinfections. Alphaherpesviruses, betaherpesviruses and gammaherpesviruses are neurotropic viruses that establish latency and exhibit reactivation capacity. Encephalitis and meningitis are common in cases of HHV. The condition promoted by HHV infection is a purported trigger for certain neurodegenerative diseases. Ongoing studies have identified an association between HSV-1 and the occurrence of Alzheimer's disease, multiple sclerosis and infections by HHV-6 and Epstein-Barr virus. In this review, we highlight the importance of research investigating the role of herpesviruses in the pathogenesis of diseases that affect the nervous system and describe other studies in progress.

SARS-CoV-2 infection and lytic reactivation of herpesviruses: A potential threat in the postpandemic era?

The outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the causative pathogen for the coronavirus disease 2019 (COVID-19) pandemic, has greatly stressed our healthcare system. In addition to severe respiratory and systematic symptoms, several comorbidities increase the risk of fatal disease outcomes, including chronic viral infections. Increasing cases of lytic reactivation of human herpesviruses in COVID-19 patients and vaccinated people have been reported recently. SARS-CoV2 coinfection, COVID-19 treatments, and vaccination may aggravate those herpesvirus-associated diseases by reactivating the viruses in latently infected host cells. In this review, we summarize recent clinical findings and limited mechanistic studies regarding the relationship between SARS-CoV-2 and different human herpesviruses that suggest an ongoing potential threat to human health in the postpandemic era.