Evidence for the role of Epstein Barr Virus infections in the pathogenesis of acute coronary events

Virus-Associated CD8+ T-Cells Are Not Activated Through Antigen-Mediated Interaction Inside Atherosclerotic Lesions

INTRODUCTION

Viral infections have been associated with the progression of atherosclerosis and CD8+ T-cells directed against common viruses, such as influenza, Epstein-Barr virus, and cytomegalovirus, have been detected inside human atherosclerotic lesions. These virus-specific CD8+ T-cells have been hypothesized to contribute to the development of atherosclerosis; however, whether they affect disease progression directly remains unclear. In this study, we aimed to characterize the activation status of virus-specific CD8+ T-cells in the atherosclerotic lesion.

METHODS

The presence, clonality, tissue enrichment, and phenotype of virus-associated CD8+ T-cells in atherosclerotic lesions were assessed by exploiting bulk T-cell receptor-β sequencing and single-cell T-cell receptor (α and β) sequencing datasets on human endarterectomy samples and patient-matched blood samples. To investigate if virus-specific CD8+ T-cells can be activated through T-cell receptor stimulation in the atherosclerotic lesion, the immunopeptidome of human plaques was determined.

RESULTS

Virus-associated CD8+ T-cells accumulated more in the atherosclerotic lesion (mean=2.0%), compared with patient-matched blood samples (mean=1.4%; P=0.05), and were more clonally expanded and tissue enriched in the atherosclerotic lesion in comparison with nonassociated CD8+ T-cells from the lesion. Single-cell T-cell receptor sequencing and flow cytometry revealed that these virus-associated CD8+ T-cells were phenotypically highly similar to other CD8+ T-cells in the lesion and that both exhibited a more activated phenotype compared with circulating T-cells. Interestingly, virus-associated CD8+ T-cells are unlikely to be activated through antigen-specific interactions in the atherosclerotic lesion, as no virus-derived peptides were detected on HLA-I in the lesion.

CONCLUSIONS

This study suggests that virus-specific CD8+ T-cells are tissue enriched in atherosclerotic lesions; however, their potential contribution to inflammation may involve antigen-independent mechanisms.

Evidence linking the association of periodontal viruses and pentraxins in periodontitis patients with coronary artery disease

BACKGROUND

Although there is ample evidence in the literature supporting a significant positive association between key periodontal pathogens and established inflammatory markers of periodontitis and coronary artery disease (CAD), their exact role remain unclear. Especially, the role of viruses in the etiology and specific biomarkers have not been validated. Thus, the current study aims to evaluate the role of periodontal viruses such as Epstein-Barr virus (EBV), cytomegalovirus (CMV), and herpes simplex virus (HSV), as well as the inflammatory marker pentraxin-3 (PTX3), and to analyze their association with CAD.

METHODS

The study included 240 patients divided into four groups of 60 patients each: nonperiodontitis + noncardiac (NP+NC) group, periodontitis + noncardiac patients (P+NC) group, nonperiodontitis + cardiac patients (NP+C) group, and periodontitis + cardiac (P+C) group. The cardiac surgery group (C-S) was a subgroup of NP+C and P+C. It consisted of 60 patients from the abovementioned two cardiac groups in whom coronary artery bypass graft (CABG) was indicated. Demographic variables, cardiac parameters, and periodontal parameters were recorded. The viruses (EBV, CMV, and HSV) and the inflammatory marker PTX3 were evaluated in the subgingival plaque samples of all the four groups and atheromatous plaque samples of the C-S using reverse transcriptase-polymerase chain reaction (RT-PCR) and quantitative polymerase chain reaction (qPCR), respectively, and were compared between the groups. The results were obtained and statistically analyzed.

RESULTS

The demographic variables did not differ significantly between the groups, except for age. Systolic blood pressure, diastolic blood pressure, low-density lipoprotein, and random blood sugar were significantly higher in NP+C and P+C, whereas high-density lipoprotein was significantly lower (p ≤ 0.05) in the same. Plaque index (PI), probing pocket depth (PPD), and clinical attachment level (CAL) were significantly higher (p ≤ 0.05) in P+NC and P+C. PTX were significantly elevated in P+C among the four groups. On evaluating the subgingival plaque samples, EBV and CMV were significantly higher in the two periodontitis groups P+NC and P+C (p = 0.000). HSV was significantly higher in the two cardiac groups (NP+C and P+C) (p ≤ 0.05). Cardiac EBV and CMV were significantly elevated in the P+C group with a p value of 0.004 and 0.033, respectively. Cardiac HSV was found in the NP+C group with statistical insignificance (p = 0.410) between the groups. On correlation, oral PTX were significantly associated with bleeding index (BI), PPD, and CAL (p = 0.000). Similarly, cardiac PTX showed significant association with PI, BI, PPD, and CAL (p = 0.000). Oral and cardiac PTX also showed significant correlation with each other. Multiple logistic regression analysis revealed a significant association between CAL and oral EBV (p ≤ 0.05). Similarly, cardiac EBV showed a significant association with CAL and oral EBV (p ≤ 0.05). Multiple logistic regression analysis also revealed that both cardiac and oral PTX showed a significant association only with oral EBV, CMV, and HSV.

CONCLUSION

The results of the current study suggest that the clinical severity of periodontitis (CAL), etiology of periodontitis (EBV and CMV), and inflammatory marker of periodontitis (PTX3) were found to be significantly elevated in CAD. These findings suggests that periodontal diseases may be a risk factor that could influence the progression of CAD.

Long COVID and hypertension-related disorders: a report from the Japanese Society of Hypertension Project Team on COVID-19

The coronavirus disease 2019 (COVID-19) affects infected patients even after the acute phase and impairs their health and quality of life by causing a wide variety of symptoms, referred to as long COVID. Although the evidence is still insufficient, hypertension is suspected to be a potential risk factor for long COVID, and the occurrence of cardiovascular diseases seems to be a key facet of multiple conditions observed in long COVID. Nonetheless, there are few reports that comprehensively review the impacts of long COVID on hypertension and related disorders. As a sequel to our previous report in 2020 which reviewed the association of COVID-19 and hypertension, we summarize the possible influences of long COVID on hypertension-related organs, including the cardiovascular system, kidney, and endocrine system, as well as the pathophysiological mechanisms associated with the disorders in this review. Given that the clinical course of COVID-19 is highly affected by age and sex, we also review the impacts of these factors on long COVID. Lastly, we discuss areas of uncertainty and future directions, which may lead to better understanding and improved prognosis of clinical problems associated with COVID-19.

Persistent viral infections and their role in heart disease

Viral infections are the culprit of many diseases, including inflammation of the heart muscle, known as myocarditis. Acute myocarditis cases have been described in scientific literature, and viruses, such as parvovirus B19, coxsackievirus B3, or more recently, SARS-CoV-2, were the direct cause of cardiac inflammation. If not treated, myocarditis could progress to dilated cardiomyopathy, which permanently impairs the heart and limits a person's lifespan. Accumulated evidence suggests that certain viruses may persist in cardiac tissue after the initial infection, which could open up the door to reactivation under favorable conditions. Whether this chronic infection contributes to, or initiates, cardiac damage over time, remains a pressing issue in the field of virus-induced heart pathology, and it is directly tied to patients' treatment. Previously, large case studies found that a few viruses: parvovirus B19, coxsackievirus, adenovirus, human herpesvirus 6, cytomegalovirus and Epstein-Barr virus, are most commonly found in human endomyocardial biopsy samples derived from patients experiencing cardiac inflammation, or dilated cardiomyopathy. SARS-CoV-2 infection has also been shown to have cardiovascular consequences. This review examines the role of viral persistence in cardiac inflammation and heart disease, and discusses its implications for patients' outcomes.

Evaluation of the periodontal viruses in cardiovascular patients associated with periodontitis

OBJECTIVES

The current study aims in evaluating the prevalence of Epstein-barr virus (EBV), Cytomegalovirus (CMV) and Herpes simplex virus (HSV) in periodontitis and/or Coronary artery disease (CAD) patients to compare with their healthy controls and insist their significance in the same.

METHODOLOGY

Two hundred and forty patients were divided into 4 groups. Non-periodontitis+non-cardiac (NP+NC) =60 patients, periodontitis+non-cardiac patients (P+NC)=60 patients, non-periodontitis+cardiac patients (NP+C)=60 patients and periodontitis+cardiac (P+C)=60 patients. Demographic variables, cardiac and periodontal parameters were recorded. EBV, CMV and HSV were evaluated in the sub- gingival plaque samples using RT-PCR (Real time polymerase chain reaction) and compared between the groups. The results were statistically analysed using Students t test, Pearson's chi square, Turkey post hoc analysis and multiple logistic regression analysis.

RESULTS

The demographic variables did not differ significantly between the groups, except for age. Systolic blood pressure, Diastolic blood pressure, Low density lipoprotein, Random blood sugar were significantly higher in NP+C and P+C (p≤0.05). The Plaque Index, Probing Pocket Depth and Clinical Attachment Loss (p≤0.05) were significantly higher in P+NC and P+C. EBV and CMV was significantly higher in the two periodontitis groups P+NC and P+C (p-value=0.000). HSV was significantly higher in the two cardiac groups (NP+C and P+C) (p≤0.05). Multiple logistic regression analysis revealed a significant association between EBV and CAL (p≤0.05).

CONCLUSION

The study concluded that higher prevalence of EBV and CMV were found in groups with periodontitis patients. This indicates the significant role of the viruses in periodontitis as confirmed by association of EBV and CAL. The viruses were said to be highest in periodontitis patients with CAD. This could pave a new link in the risk of CAD in periodontitis patients.

Advanced detection strategies for cardiotropic virus infection in a cohort study of heart failure patients

The prevalence and contribution of cardiotropic viruses to various expressions of heart failure are increasing, yet primarily underappreciated and underreported due to variable clinical syndromes, a lack of consensus diagnostic standards and insufficient clinical laboratory tools. In this study, we developed an advanced methodology for identifying viruses across a spectrum of heart failure patients. We designed a custom tissue microarray from 78 patients with conditions commonly associated with virus-related heart failure, conditions where viral contribution is typically uncertain, or conditions for which the etiological agent remains suspect but elusive. Subsequently, we employed advanced, highly sensitive in situ hybridization to probe for common cardiotropic viruses: adenovirus 2, coxsackievirus B3, cytomegalovirus, Epstein-Barr virus, hepatitis C and E, influenza B and parvovirus B19. Viral RNA was detected in 46.4% (32/69) of heart failure patients, with 50% of virus-positive samples containing more than one virus. Adenovirus 2 was the most prevalent, detected in 27.5% (19/69) of heart failure patients, while in contrast to previous reports, parvovirus B19 was detected in only 4.3% (3/69). As anticipated, viruses were detected in 77.8% (7/9) of patients with viral myocarditis and 37.5% (6/16) with dilated cardiomyopathy. Additionally, viruses were detected in 50% of patients with coronary artery disease (3/6) and hypertrophic cardiomyopathy (2/4) and in 28.6% (2/7) of transplant rejection cases. We also report for the first time viral detection within a granulomatous lesion of cardiac sarcoidosis and in giant cell myocarditis, conditions for which etiological agents remain unknown. Our study has revealed a higher than anticipated prevalence of cardiotropic viruses within cardiac muscle tissue in a spectrum of heart failure conditions, including those not previously associated with a viral trigger or exacerbating role. Our work forges a path towards a deeper understanding of viruses in heart failure pathogenesis and opens possibilities for personalized patient therapeutic approaches.

Investigation of Long COVID Prevalence and Its Relationship to Epstein-Barr Virus Reactivation

Coronavirus disease 2019 (COVID-19) patients sometimes experience long-term symptoms following resolution of acute disease, including fatigue, brain fog, and rashes. Collectively these have become known as long COVID. Our aim was to first determine long COVID prevalence in 185 randomly surveyed COVID-19 patients and, subsequently, to determine if there was an association between occurrence of long COVID symptoms and reactivation of Epstein–Barr virus (EBV) in 68 COVID-19 patients recruited from those surveyed. We found the prevalence of long COVID symptoms to be 30.3% (56/185), which included 4 initially asymptomatic COVID-19 patients who later developed long COVID symptoms. Next, we found that 66.7% (20/30) of long COVID subjects versus 10% (2/20) of control subjects in our primary study group were positive for EBV reactivation based on positive titers for EBV early antigen-diffuse (EA-D) IgG or EBV viral capsid antigen (VCA) IgM. The difference was significant (p < 0.001, Fisher’s exact test). A similar ratio was observed in a secondary group of 18 subjects 21–90 days after testing positive for COVID-19, indicating reactivation may occur soon after or concurrently with COVID-19 infection. These findings suggest that many long COVID symptoms may not be a direct result of the SARS-CoV-2 virus but may be the result of COVID-19 inflammation-induced EBV reactivation.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: The Human Herpesviruses Are Back!

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) or Systemic Exertion Intolerance Disease (SEID) is a chronic multisystem illness of unconfirmed etiology. There are currently no biomarkers and/or signatures available to assist in the diagnosis of the syndrome and while numerous mechanisms have been hypothesized to explain the pathology of ME/CFS, the triggers and/or drivers remain unknown. Initial studies suggested a potential role of the human herpesviruses especially Epstein-Barr virus (EBV) in the disease process but inconsistent and conflicting data led to the erroneous suggestion that these viruses had no role in the syndrome. New studies using more advanced approaches have now demonstrated that specific proteins encoded by EBV could contribute to the immune and neurological abnormalities exhibited by a subgroup of patients with ME/CFS. Elucidating the role of these herpesvirus proteins in ME/CFS may lead to the identification of specific biomarkers and the development of novel therapeutics.

Matrix Metalloproteinase-13 in Atherosclerotic Plaque Is Increased by Influenza A Virus Infection

BACKGROUND

Influenza virus infection triggers acute cardiovascular events. Several studies have demonstrated that influenza A virus infection was associated with immune cell influx and increased production of inflammatory cytokines in the atherosclerotic plaque lesion, but the underlying mechanism for these findings is not clear.

METHODS

We examined the expression levels of matrix metalloproteinases (MMPs) by influenza A virus infection in human cells using quantitative real-time polymerase chain reaction, Western blot, and human MMP-13 enzyme-linked immunosorbent assay. In an animal study, protein expression in the plaque lesions of apolipoprotein E (ApoE)-deficient mice were analyzed by immunohistochemistry and Western blot.

RESULTS

We confirmed that MMP-13 was increased in influenza A virus-infected cells. In the aorta of infected ApoE-deficient mice, MMP-13 was increased at 3 days after infection. Immunohistochemical staining results suggested that collagen was degraded in the MMP-13 expression area and that macrophages were the main source of MMP-13 expression. Furthermore, the expression of MMP-13 was regulated by influenza A virus through activation of the p38 mitogen-activated protein kinase (MAPK) signaling pathway.

CONCLUSIONS

In this study, we demonstrated that p38 MAPK-mediated MMP-13 expression by influenza A virus infection led to destabilization of vulnerable atherosclerotic plaques in the artery.

Evidence linking the role of periodontal viruses in coronary artery disease with and without periodontitis

BACKGROUND

Viruses are considered to be a newer family associated with inflammatory diseases. Yet the role of periodontal viruses in coronary artery diseases (CAD) remains unclear. Thus, the current study aims to evaluate the prevalence of periodontal viruses and compare the same in cardiac samples of CAD patients with and without periodontitis.

METHODS

A total of 60 patients with CAD indicated for coronary artery bypass graft surgery (CABG) were included. These were grouped into 36 patients with healthy periodontium (CAD only) and 24 patients with periodontitis (CAD + P). The demographic variables, cardiac parameters and periodontal parameters were recorded. Cardiac tissue samples were collected during the CABG surgery and were analyzed by reverse transcriptase polymerase chain reaction for periodontal viruses such as Epstein-Barr virus (EBV), cytomegalovirus (CMV) and Herpes simplex virus. All the parameters were statistically analyzed.

RESULTS

Among the demographic variables, age was statistically significant between the groups. Plaque index, bleeding index, probing depth, and clinical attachment level (CAL) were significantly higher in CAD+P group (P ˂0.05). Periodontal viruses such as EBV and CMV were significantly higher (62.5% and 75% respectively, P ˂0.05) in the cardiac samples of the CAD+P than CAD only (25% and 47.2%, respectively). A significant association between EBV and CAL was revealed by multiple logistic regression analysis. (B = 0.374, P = 0.046) CONCLUSIONS: The results revealed a higher prevalence of periodontal viruses such as EBV and CMV in CAD patients with periodontitis suggesting it as one of the risk factors for CAD. This is supported by the fact that severity of periodontal disease (CAL) is associated with the presence of EBV in coronary artery plaque samples in the current study.

Sex differences in executive functioning and latent herpesvirus reactivation among bereaved and non-bereaved individuals

The death of a spouse is a highly stressful event. Better executive functioning has been shown to benefit men to a greater degree than women during stress. We evaluated potential sex differences in stress and immune dysregulation among control and bereaved participants who completed a self-report measure of perceived stress, neuropsychological measures of inhibition and updating/monitoring of information in working memory, and a blood draw to measure Epstein-Barr virus (EBV) antibody titres. Moderation analyses were conducted to test the hypothesis that better inhibition would be associated with less stress and immune dysregulation among male bereaved participants compared with female bereaved participants. Bereaved females demonstrated greater EBV antibody titres than bereaved males. Male bereaved participants benefited from better inhibition, as evidenced by fewer EBV antibody titres, whereas bereaved female participants did not. In the control group, males with high inhibition reported lower stress than males with low inhibition. Present study results are an important step towards identifying those at greatest risk of stress and poor health.

[Detection of Antigens of Cardiotropic Viruses in Atherosclerotic Plaques in Patients with Fatal Myocardial Infarction]

AIM

To assess the frequency of detection of cardiotropic virus antigens in coronary artery atherosclerotic plaques in patients with fatal myocardial infarction (MI).

MATERIALS AND METHODS

We examined fragments of coronary plaques of 12 patients with fatal type 1 MI. Immunohistochemistry (IHC) of plaques was performed with the paraffin blocks using antibodies to Herpes simplex virus (HSV)-1, HSV-2, HSV-6, cytomegalovirus (CMV), parvovirus B19, adenovirus, Epstein-Barr virus and enteroviruses.

RESULTS

According to the IHC all patients had virus antigens. The most common virus agents in fragments of coronary plaques were HSV-6 (10 patients) and enteroviruses (5 patients). Antigens of CMV, parvovirus B19, adenovirus, Epstein-Barr virus were not detected in any case.

CONCLUSIONS

In this study viral antigens in coronary artery atherosclerotic plaques were found in all victims of fatal MI. There was no difference in the frequency of detection and type of viral agents between plaques in culprit arteries and uncomplicated atherosclerotic plaques.

Validation of Multiplex Serology detecting human herpesviruses 1-5

Human herpesviruses (HHV) cause a variety of clinically relevant conditions upon primary infection of typically young and immunocompetent hosts. Both primary infection and reactivation after latency can lead to more severe disease, such as encephalitis, congenital defects and cancer. Infections with HHV are also associated with cardiovascular and neurodegenerative disease. However, most of the associations are based on retrospective case-control analyses and well-powered prospective cohort studies are needed for assessing temporality and causality. To enable comprehensive investigations of HHV-related disease etiology in large prospective population-based cohort studies, we developed HHV Multiplex Serology. This methodology represents a low-cost, high-throughput technology that allows simultaneous measurement of specific antibodies against five HHV species: Herpes simplex viruses 1 and 2, Varicella zoster virus, Epstein-Barr virus, and Cytomegalovirus. The newly developed HHV species-specific ('Monoplex') assays were validated against established gold-standard reference assays. The specificity and sensitivity of the HHV species-specific Monoplex Serology assays ranged from 92.3% to 100.0% (median 97.4%) and 91.8% to 98.7% (median 96.6%), respectively. Concordance with reference assays was very high with kappa values ranging from 0.86 to 0.96 (median kappa 0.93). Multiplexing the Monoplex Serology assays resulted in no loss of performance and allows simultaneous detection of antibodies against the 5 HHV species in a high-throughput manner.

Herpesviruses dUTPases: A New Family of Pathogen-Associated Molecular Pattern (PAMP) Proteins with Implications for Human Disease

The human herpesviruses are ubiquitous viruses and have a prevalence of over 90% in the adult population. Following a primary infection they establish latency and can be reactivated over a person's lifetime. While it is well accepted that human herpesviruses are implicated in numerous diseases ranging from dermatological and autoimmune disease to cancer, the role of lytic proteins in the pathophysiology of herpesvirus-associated diseases remains largely understudies. Only recently have we begun to appreciate the importance of lytic proteins produced during reactivation of the virus, in particular the deoxyuridine triphosphate nucleotidohydrolases (dUTPase), as key modulators of the host innate and adaptive immune responses. In this review, we provide evidence from animal and human studies of the Epstein-Barr virus as a prototype, supporting the notion that herpesviruses dUTPases are a family of proteins with unique immunoregulatory functions that can alter the inflammatory microenvironment and thus exacerbate the immune pathology of herpesvirus-related diseases including myalgic encephalomyelitis/chronic fatigue syndrome, autoimmune diseases, and cancer.

Maternal Antibodies to Herpes Virus Antigens and Risk of Gastroschisis in Offspring

Gastroschisis risk is highest in offspring of young women and is increasing in prevalence, suggesting that exposures that are increasingly common among younger females may be causal. Some infections by viruses in the herpes family are more common in the earlier childbearing years and have been increasing in prevalence over time. Data from the Finnish Maternity Cohort were linked to Finnish malformation and birth registers (1987-2012) for this study, a nested case-control study of mothers of offspring with gastroschisis and age-matched controls. Maternal antibody responses in early pregnancy (mean gestational age = 11.1 weeks) to Epstein Barr virus (EBV), herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), and cytomegalovirus were measured. Conditional logistic regression models were used to estimate odds ratios (and 95% confidence intervals) for high immunoglobulin reactivity. Odds ratios for high immunoglobulin M (IgM) reactivity to EBV-viral capsid antigen and HSV-1 or HSV-2 (as indicators of recent infection) were 2.16 (95% confidence interval (CI): 0.97, 4.79) and 1.94 (95% CI: 0.74, 5.12), respectively. For higher immunoglobulin G (IgG) reactivity to EBV-viral capsid antigen and HSV-2 IgG, odds ratios were 2.16 (95% CI: 0.82, 5.70) and 2.48 (95% CI: 1.50, 4.10), respectively. Reactivities to HSV-1 IgG, cytomegalovirus IgM, or cytomegalovirus IgG did not appear to increase gastroschisis risk. Primary EBV infection was not associated with gastroschisis, but observed associations with both IgM and IgG reactivities to EBV and HSV suggest that reactivations may be risk factors for it.

Luteolin inhibits Epstein-Barr virus lytic reactivation by repressing the promoter activities of immediate-early genes

The lytic reactivation of Epstein-Barr virus (EBV) has been reported to be strongly associated with several human diseases, including nasopharyngeal carcinoma (NPC). Inhibition of the EBV lytic cycle has been shown to be of great benefit in the treatment of EBV-associated diseases. The administration of dietary compounds is safer and more convenient than other approaches to preventing EBV reactivation. We screened several dietary compounds for their ability to inhibit EBV reactivation in NPC cells. Among them, the flavonoid luteolin showed significant inhibition of EBV reactivation. Luteolin inhibited protein expression from EBV lytic genes in EBV-positive epithelial and B cell lines. It also reduced the numbers of EBV-reactivating cells detected by immunofluorescence analysis and reduced the production of virion. Furthermore, luteolin reduced the activities of the promoters of the immediate-early genes Zta (Zp) and Rta (Rp) and also inhibited Sp1-luc activity, suggesting that disruption of Sp1 binding is involved in the inhibitory mechanism. CHIP analysis revealed that luteolin suppressed the activities of Zp and Rp by deregulating Sp1 binding. Taken together, luteolin inhibits EBV reactivation by repressing the promoter activities of Zp and Rp, suggesting luteolin is a potential dietary compound for prevention of virus infection.

Atypical manifestations of Epstein-Barr virus in children: a diagnostic challenge

OBJECTIVE

Clarify the frequency and the pathophysiological mechanisms of the rare manifestations of Epstein-Barr virus infection.

SOURCES

Original research studies published in English between 1985 and 2015 were selected through a computer-assisted literature search (PubMed and Scopus). Computer searches used combinations of key words relating to "EBV infections" and "atypical manifestation."

SUMMARY OF THE FINDINGS

Epstein-Barr virus is a herpes virus responsible for a lifelong latent infection in almost every adult. The primary infection concerns mostly children and presents with the clinical syndrome of infectious mononucleosis. However, Epstein-Barr virus infection may exhibit numerous rare, atypical and threatening manifestations. It may cause secondary infections and various complications of the respiratory, cardiovascular, genitourinary, gastrointestinal, and nervous systems. Epstein-Barr virus also plays a significant role in pathogenesis of autoimmune diseases, allergies, and neoplasms, with Burkitt lymphoma as the main representative of the latter. The mechanisms of these manifestations are still unresolved. Therefore, the main suggestions are direct viral invasion and chronic immune response due to the reactivation of the latent state of the virus, or even various DNA mutations.

CONCLUSIONS

Physicians should be cautious about uncommon presentations of the viral infection and consider EBV as a causative agent when they encounter similar clinical pictures.

Tuberculosis and Cardiovascular Disease: Linking the Epidemics

The burden of tuberculosis and cardiovascular disease (CVD) is enormous worldwide. CVD rates are rapidly increasing in low- and middle-income countries. Public health programs have been challenged with the overlapping tuberculosis and CVD epidemics. Monocyte/macrophages, lymphocytes and cytokines involved in cellular mediated immune responses against Mycobacterium tuberculosis are also main drivers of atherogenesis, suggesting a potential pathogenic role of tuberculosis in CVD via mechanisms that have been described for other pathogens that establish chronic infection and latency. Studies have shown a pro-atherogenic effect of antibody-mediated responses against mycobacterial heat shock protein-65 through cross reaction with self-antigens in human vessels. Furthermore, subsets of mycobacteria actively replicate during latent tuberculosis infection (LTBI), and recent studies suggest that LTBI is associated with persistent chronic inflammation that may lead to CVD. Recent epidemiologic work has shown that the risk of CVD in persons who develop tuberculosis is higher than in persons without a history of tuberculosis, even several years after recovery from tuberculosis. Together, these data suggest that tuberculosis may play a role in the pathogenesis of CVD. Further research to investigate a potential link between tuberculosis and CVD is warranted.

The Putative Role of Viruses, Bacteria, and Chronic Fungal Biotoxin Exposure in the Genesis of Intractable Fatigue Accompanied by Cognitive and Physical Disability

Patients who present with severe intractable apparently idiopathic fatigue accompanied by profound physical and or cognitive disability present a significant therapeutic challenge. The effect of psychological counseling is limited, with significant but very slight improvements in psychometric measures of fatigue and disability but no improvement on scientific measures of physical impairment compared to controls. Similarly, exercise regimes either produce significant, but practically unimportant, benefit or provoke symptom exacerbation. Many such patients are afforded the exclusionary, non-specific diagnosis of chronic fatigue syndrome if rudimentary testing fails to discover the cause of their symptoms. More sophisticated investigations often reveal the presence of a range of pathogens capable of establishing life-long infections with sophisticated immune evasion strategies, including Parvoviruses, HHV6, variants of Epstein-Barr, Cytomegalovirus, Mycoplasma, and Borrelia burgdorferi. Other patients have a history of chronic fungal or other biotoxin exposure. Herein, we explain the epigenetic factors that may render such individuals susceptible to the chronic pathology induced by such agents, how such agents induce pathology, and, indeed, how such pathology can persist and even amplify even when infections have cleared or when biotoxin exposure has ceased. The presence of active, reactivated, or even latent Herpes virus could be a potential source of intractable fatigue accompanied by profound physical and or cognitive disability in some patients, and the same may be true of persistent Parvovirus B12 and mycoplasma infection. A history of chronic mold exposure is a feasible explanation for such symptoms, as is the presence of B. burgdorferi. The complex tropism, life cycles, genetic variability, and low titer of many of these pathogens makes their detection in blood a challenge. Examination of lymphoid tissue or CSF in such circumstances may be warranted.

Exposure to neighborhood immigrant concentration from adolescence to young adulthood and immune function among Latino young adults

The immune system plays a critical role in the prevention of infectious and chronic disease. We investigate associations between exposure to neighborhood immigrant concentration across the transition from adolescence to adulthood and immune function among Latino young adults, including moderation by nativity. Data from the National Longitudinal Study of Adolescent Health (1994-2008) were analyzed. Immune function was measured via Epstein-Barr virus (EBV) antibody levels (higher levels indicate impaired immune function) among EBV-positive Latino adults (N=1130). Results indicated the averaged individual exposure to immigrant concentration (mean % of foreign-born residents in the census tract across waves 1-4) was associated with immune function for foreign-born Latinos only (b=-0.37, P<0.05). For waves of exposure, only the cumulative measure of living in an immigrant enclave (census tracts with ≥40% foreign-born residents) across all waves was associated with immune function and only for foreign-born Latinos (b=-0.22, P<0.05). Research on the mechanisms through which neighborhood immigrant concentration confers salubrious physiological outcomes for foreign-born Latinos is needed.

Human herpesviruses-encoded dUTPases: a family of proteins that modulate dendritic cell function and innate immunity

We have previously shown that Epstein-Barr virus (EBV)-encoded dUTPase can modulate innate immune responses through the activation of TLR2 and NF-κB signaling. However, whether this novel immune function of the dUTPase is specific for EBV or a common property of the Herpesviridae family is not known. In this study, we demonstrate that the purified viral dUTPases encoded by herpes simplex virus type 2 (HSV-2), human herpesvirus-6A (HHV-6A), human herpesvirus-8 (HHV-8) and varicella-zoster virus (VZV) differentially activate NF-κB through ligation of TLR2/TLR1 heterodimers. Furthermore, activation of NF-κB by the viral dUTPases was inhibited by anti-TLR2 blocking antibodies (Abs) and the over-expression of dominant-negative constructs of TLR2, lacking the TIR domain, and MyD88 in human embryonic kidney 293 cells expressing TLR2/TLR1. In addition, treatment of human dendritic cells and PBMCs with the herpesviruses-encoded dUTPases from HSV-2, HHV-6A, HHV-8, and VZV resulted in the secretion of the inflammatory cytokines IL-1β, IL-6, IL-8, IL-12, TNF-α, IL-10, and IFN-γ. Interestingly, blocking experiments revealed that the anti-TLR2 Ab significantly reduced the secretion of cytokines by the various herpesviruses-encoded dUTPases (p < 0.05). To our knowledge, this is the first report demonstrating that a non-structural protein encoded by herpesviruses HHV-6A, HHV-8, VZV and to a lesser extent HSV-2 is a pathogen-associated molecular pattern. Our results reveal a novel function of the virus-encoded dUTPases, which may be important to the pathophysiology of diseases caused by these viruses. More importantly, this study demonstrates that the immunomodulatory functions of dUTPases are a common property of the Herpesviridae family and thus, the dUTPase could be a potential target for the development of novel therapeutic agents against infections caused by these herpesviruses.

Effect of Vitamin D3 on Monocyte Chemoattractant Protein 1 Production in Monocytes and Macrophages

BACKGROUND

Chemokine is important in the initiation and progression of atherosclerosis, the clinically manifest stages of atherosclerosis and acute coronary syndrome. Vitamin D deficiency has been reportedly linked with hypertension and myocardial infarction, as well as other cardiovascular-related diseases, such as congestive heart failure, peripheral vascular disease and atherosclerosis. Monocyte chemoattractant protein 1 (MCP-1) mediates atherosclerosis and other cardiovascular diseases. However, there have been few studies conducted about the role of 1α,25-(OH)2D3 on MCP-1 expression in human monocytes.

METHODS

We investigated the effects of vitamin A, C and 1α,25-(OH)2D3, three common vitamins, to better ascertain MCP-1 expression in human monocyte and also the associated intracellular mechanism. Human monocyte cell line (THP-1 cell) and THP-1 cell-induced macrophage were treated with varying doses of vitamin A, C and 1α,25-(OH)2D3 for 2 hours before LPS stimulation. Supernatants were harvested to measure MCP-1 levels by the enzyme-linked immunosorbent assay (ELISA). The intracellular mechanism about the effects of vitamin A, C and 1α,25-(OH)2D3 on the expression of MCP-1 expression in human monocytes was assessed by western blot.

RESULTS

We found that Lipopolysaccharides (LPS)-induced MCP-1 production was suppressed by 1α,25-(OH)2D3 in THP-1 cells and THP-1-induced macrophage. Only high concentration of vitamin A and C could reduce LPS-induced MCP-1 production in THP-1-induced macrophage, but not in THP-1 cells. LPS-induced p38 expression in THP-1 cells was suppressed by 1α,25-(OH)2D3. A selective p38 pathway inhibitor SB203580 could also suppress LPS-induced MCP-1 production. However, vitamin D receptor blocking antibody could reverse the suppressive effect of 1α,25-(OH)2D3 on MCP-1 expression.

CONCLUSIONS

These data demonstrate that 1α,25-(OH)2D3 is effective in down-regulating LPS-induced MCP-1. The suppressive effect on MCP-1 may, at least in part, involve the vitamin D receptor and down-regulation of LPS - induced p38 expression.

KEY WORDS

Chemokine; Monocyte chemoattractant protein 1 (MCP-1); Monocyte; p38; Vitamin D.

Impact of viral and bacterial infections in coronary artery disease patients

Atherosclerosis is becoming an alarming disease for the existence of healthy human beings in the 21^st century. There are a growing number of agents, either modernized life style generated, competitive work culture related or infection with some bacterial or viral agents, documented every year. These infectious agents do not have proper diagnostics or detection availability in many poor and developing countries. Hence, as active medical researchers, we summarize some aspects of infectious agents and their related mechanisms in this review which may be beneficial for new beginners in this field and update awareness in the field of cardiovascular biology.

Seroprevalence of Epstein-Barr virus infection in U.S. children ages 6-19, 2003-2010

BACKGROUND

Epstein-Barr virus (EBV) is a common herpesvirus linked to infectious mononucleosis and multiple cancers. There are no national estimates of EBV seroprevalence in the United States. Our objective was to estimate the overall prevalence and sociodemographic predictors of EBV among U.S. children and adolescents aged 6-19.

METHODS

We calculated prevalence estimates and prevalence ratios for EBV seroprevalence using data from the 2003-2010 U.S. National Health and Nutrition Examination Survey (NHANES) for children aged 6-19 (n = 8417). Poisson regression was used to calculate multivariable-adjusted prevalence ratios across subgroup categories (sex, race/ethnicity, parental education, household income, household size, foreign-born, BMI, and household smoking).

FINDINGS

Overall EBV seroprevalence was 66.5% (95% CI 64.3%-68.7%.). Seroprevalence increased with age, ranging from 54.1% (95% CI 50.2%-57.9%) for 6-8 year olds to 82.9% (95% CI 80.0%-85.9%) for 18-19 year olds. Females had slightly higher seroprevalence (68.9%, 95% CI 66.3%-71.6%) compared to males (64.2%, 95% CI 61.7%-66.8%). Seroprevalence was substantially higher for Mexican-Americans (85.4%, 95% CI 83.1%-87.8%) and Non-Hispanic Blacks (83.1%, 95% CI 81.1%-85.1%) than Non-Hispanic Whites (56.9%, 95% CI 54.1%-59.8%). Large differences were also seen by family income, with children in the lowest income quartile having 81.0% (95% CI 77.6%-84.5%) seroprevalence compared to 53.9% (95% CI 50.5%-57.3%) in the highest income quartile, with similar results for parental education level. These results were not explained by household size, BMI, or parental smoking. Among those who were seropositive, EBV antibody titers were significantly higher for females, Non-Hispanic Blacks and Mexican-Americans, with no association found for socioeconomic factors.

CONCLUSIONS

In the first nationally representative U.S. estimates, we found substantial socioeconomic and race/ethnic differences in the seroprevalence of EBV across all ages for U.S. children and adolescents. These estimates can help researchers and clinicians identify groups most at risk, inform research on EBV-cancer etiology, and motivate potential vaccine development.