Association between prior cytomegalovirus infection and the risk of restenosis after coronary atherectomy

Human cytomegalovirus and Epstein-Barr virus infections occurring early after transplantation are risk factors for antibody-mediated rejection in heart transplant recipients

Background

Antibody-mediated rejection (AMR) is a serious complication affecting the survival of patients receiving transplantation. Human cytomegalovirus (CMV) and Epstein-Barr virus (EBV) are common viral infections that occur after transplantation, frequently emerging as viral reactivation in donor grafts or transplant recipients. The present study aimed to investigate the association between CMV and EBV infections and early-onset AMR.

Materials and methods

This study was conducted at the Heart Transplantation Center of Padova General Hospital and included a cohort of 47 heart transplant recipients (HTxs), including 24 HTxs diagnosed with AMR and 23 control HTxs with no episodes of AMR. Only early cases of CMV and/or EBV infections (1-90 days after transplantation) were considered. Fisher's exact test and logistic regression analysis were used to statistically analyze the correlation and association between AMR and CMV or EBV infection.

Results

We observed a positive statistical association between CMV and EBV infections (two-sided Fisher's exact test, p = 0.0136) and between EBV infection and AMR (two-sided Fisher's exact test, p = 0.0034). Logistic regression analysis revealed a direct statistical association between CMV and EBV infections and AMR risk (p = 0.037 and 0.006 and odds ratio = 1.72 and 2.19, respectively). AMR occurrence was associated with increased viral loads of both CMV and EBV early after transplantation.

Discussion

These findings suggest the role of CMV and EBV infections as relevant risk factors for AMR in HTxs for the first time.

Metabolic syndrome and aberrant immune responses to viral infection and vaccination: Insights from small animal models

This review outlines the propensity for metabolic syndrome (MetS) to induce elevated disease severity, higher mortality rates post-infection, and poor vaccination outcomes for viral pathogens. MetS is a cluster of conditions including high blood glucose, an increase in circulating low-density lipoproteins and triglycerides, abdominal obesity, and elevated blood pressure which often overlap in their occurrence. MetS diagnoses are on the rise, as reported cases have increased by greater than 35% since 1988, resulting in one-third of United States adults currently diagnosed as MetS patients. In the aftermath of the 2009 H1N1 pandemic, a link between MetS and disease severity was established. Since then, numerous studies have been conducted to illuminate the impact of MetS on enhancing virally induced morbidity and dysregulation of the host immune response. These correlative studies have emphasized the need for elucidating the mechanisms by which these alterations occur, and animal studies conducted as early as the 1940s have linked the conditions associated with MetS with enhanced viral disease severity and poor vaccine outcomes. In this review, we provide an overview of the importance of considering overall metabolic health in terms of cholesterolemia, glycemia, triglyceridemia, insulin and other metabolic molecules, along with blood pressure levels and obesity when studying the impact of metabolism-related malignancies on immune function. We highlight the novel insights that small animal models have provided for MetS-associated immune dysfunction following viral infection. Such animal models of aberrant metabolism have paved the way for our current understanding of MetS and its impact on viral disease severity, dysregulated immune responses to viral pathogens, poor vaccination outcomes, and contributions to the emergence of viral variants.

Human Cytomegalovirus Reduces Endothelin-1 Expression in Both Endothelial and Vascular Smooth Muscle Cells

Human cytomegalovirus (HCMV) is an opportunistic pathogen that has been implicated in the pathogenesis of atherosclerosis. Endothelin-1 (ET-1), a potent vasoconstrictive peptide, is overexpressed and strongly associated with many vasculopathies. The main objective of this study was to investigate whether HCMV could affect ET-1 production. As such, both endothelial and smooth muscle cells, two primary cell types involved in the pathogenesis of atherosclerosis, were infected with HCMV in vitro and ET-1 mRNA and proteins were assessed by quantitative PCR assay, immunofluorescence staining and ELISA. HCMV infection significantly decreased ET-1 mRNA and secreted bioactive ET-1 levels from both cell types and promoted accumulation of the ET-1 precursor protein in infected endothelial cells. This was associated with inhibition of expression of the endothelin converting enzyme-1 (ECE-1), which cleaves the ET-1 precursor protein to mature ET-1. Ganciclovir treatment did not prevent the virus suppressive effects on ET-1 expression. Consistent with this observation we identified that the IE2-p86 protein predominantly modulated ET-1 expression. Whether the pronounced effects of HCMV in reducing ET-1 expression in vitro may lead to consequences for regulation of the vascular tone in vivo remains to be proven.

The p53 pathway in vasculature revisited: A therapeutic target for pathological vascular remodeling?

Pathological vascular remodeling contributes to the development of restenosis following intraluminal interventions, transplant vasculopathy, and pulmonary arterial hypertension. Activation of the tumor suppressor p53 may counteract vascular remodeling by inhibiting aberrant proliferation of vascular smooth muscle cells and repressing vascular inflammation. In particular, the development of different lines of small-molecule p53 activators ignites the hope of treating remodeling-associated vascular diseases by targeting p53 pharmacologically. In this review, we discuss the relationships between p53 and pathological vascular remodeling, and summarize current experimental data suggesting that drugging the p53 pathway may represent a novel strategy to prevent the development of vascular remodeling.

Don't Go Breaking My Heart: MCMV as a Model for HCMV-Associated Cardiovascular Diseases

Human Cytomegalovirus (HCMV) is a widespread pathogen that causes lifelong latent infection and is associated with the exacerbation of chronic inflammatory diseases in seropositive individuals. Of particular impact, HCMV infection is known to worsen many cardiovascular diseases including myocarditis, atherosclerosis, hypertension, and transplant vasculopathy. Due to its similarity to HCMV, murine CMV (MCMV) is an appropriate model to understand HCMV-induced pathogenesis in the heart and vasculature. MCMV shares similar sequence homology and recapitulates much of the HCMV pathogenesis, including HCMV-induced cardiovascular diseases. This review provides insight into HCMV-associated cardiovascular diseases and the murine model of MCMV infection, which has been used to study the viral pathogenesis and mechanisms contributing to cardiovascular diseases. Our new functional studies using echocardiography demonstrate tachycardia and hypertrophy in the mouse, similar to HCMV-induced myocarditis in humans. For the first time, we show long term heart dysfunction and that MCMV reactivates from latency in the heart, which raises the intriguing idea that HCMV latency and frequent virus reactivation perturbs long term cardiovascular function.

Cytomegalovirus Disease, Short-Term Cardiovascular Events and Graft Survival in a Cohort of Kidney Transplant Recipients With High CMV IgG Seroprevalence

INTRODUCTION

Both cytomegalovirus (CMV) infection and CMV disease have been linked with several long-term indirect effects in kidney transplant recipients. Research questions: We conducted a retrospective study to assess the association between cytomegalovirus disease and risks of death, shortterm cardiovascular events and graft loss in a cohort of renal transplant recipients.

DESIGN

The associations between CMV disease and death and cardiovascular events were determined using Cox regression models, while the association between viral disease and graft loss risk was analyzed through a competing risks regression according to the Fine and Gray method. Death with a functioning graft was considered as a competing risk event.

RESULTS

A total of 865 consecutive renal transplant recipients were included. The prevalence of seropositive donor/seronegative recipient (D+/R-) group was 89.9% with the remaining patients classified as seropositive recipient (R+). After median follow-up time of 24.4 months, CMV disease was not a risk factor for all-causes mortality (HR = 1.75; 95% CI 0.94-3.25), early cardiovascular events (HR = 0.54; 95% CI 0.16-1.82) or graft loss (subhazard ratio [the HR adjusted for competing risk of death with functioning graft] = 0.99; 95% CI 0.53-1.84).

CONCLUSIONS

In this cohort with high prevalence of CMV IgG antibodies, we found no association between cytomegalovirus disease and risk of death or graft loss. The relationship between CMV and cardiovascular disease remains to be unraveled and probably corresponds to a multifactorial phenomenon involving individual risk factors and the immune response to infection rather than the virus effect itself.

Overview of Human Cytomegalovirus Pathogenesis

Human cytomegalovirus (HCMV) is a betaherpesvirus with a global seroprevalence of 60-90%. HCMV is the leading cause of congenital infections and poses a great health risk to immunocompromised individuals. Although HCMV infection is typically asymptomatic in the immunocompetent population, infection can result in mononucleosis and has also been associated with the development of certain cancers, as well as chronic inflammatory diseases such as various cardiovascular diseases. In immunocompromised patients, including AIDS patients, transplant recipients, and developing fetuses, HCMV infection is associated with increased rates of morbidity and mortality. Currently there is no vaccine for HCMV and there is a need for new pharmacological treatments. Ongoing research seeks to further define the complex aspects of HCMV pathogenesis, which could potentially lead to the generation of new therapeutics to mitigate the disease states associated with HCMV infection. The following chapter reviews the advancements in our understanding of HCMV pathogenesis in the immunocompetent and immunocompromised hosts.

Antiviral anticoagulation

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel envelope virus that causes coronavirus disease 2019 (COVID-19). Hallmarks of COVID-19 are a puzzling form of thrombophilia that has elevated D-dimer but only modest effects on other parameters of coagulopathy. This is combined with severe inflammation, often leading to acute respiratory distress and possible lethality. Coagulopathy and inflammation are interconnected by the transmembrane receptor, tissue factor (TF), which initiates blood clotting as a cofactor for factor VIIa (FVIIa)-mediated factor Xa (FXa) generation. TF also functions from within the nascent TF/FVIIa/FXa complex to trigger profound changes via protease-activated receptors (PARs) in many cell types, including SARS-CoV-2-trophic cells. Therefore, aberrant expression of TF may be the underlying basis of COVID-19 symptoms. Evidence suggests a correlation between infection with many virus types and development of clotting-related symptoms, ranging from heart disease to bleeding, depending on the virus. Since numerous cell types express TF and can act as sites for virus replication, a model envelope virus, herpes simplex virus type 1 (HSV1), has been used to investigate the uptake of TF into the envelope. Indeed, HSV1 and other viruses harbor surface TF antigen, which retains clotting and PAR signaling function. Strikingly, envelope TF is essential for HSV1 infection in mice, and the FXa-directed oral anticoagulant apixaban had remarkable antiviral efficacy. SARS-CoV-2 replicates in TF-bearing epithelial and endothelial cells and may stimulate and integrate host cell TF, like HSV1 and other known coagulopathic viruses. Combined with this possibility, the features of COVID-19 suggest that it is a TFopathy, and the TF/FVIIa/FXa complex is a feasible therapeutic target.

Identification of HCMV-derived T cell epitopes in seropositive individuals through viral deletion models

In healthy individuals, immune control of persistent human cytomegalovirus (HCMV) infection is effectively mediated by virus-specific CD4+ and CD8+ T cells. However, identifying the repertoire of T cell specificities for HCMV is hampered by the immense protein coding capacity of this betaherpesvirus. Here, we present a novel approach that employs HCMV deletion mutant viruses lacking HLA class I immunoevasins and allows direct identification of naturally presented HCMV-derived HLA ligands by mass spectrometry. We identified 368 unique HCMV-derived HLA class I ligands representing an unexpectedly broad panel of 123 HCMV antigens. Functional characterization revealed memory T cell responses in seropositive individuals for a substantial proportion (28%) of these novel peptides. Multiple HCMV-directed specificities in the memory T cell pool of single individuals indicate that physiologic anti-HCMV T cell responses are directed against a broad range of antigens. Thus, the unbiased identification of naturally presented viral epitopes enabled a comprehensive and systematic assessment of the physiological repertoire of anti-HCMV T cell specificities in seropositive individuals.

The Differentiation of Human Cytomegalovirus Infected-Monocytes Is Required for Viral Replication

Viral dissemination is a key mechanism responsible for persistence and disease following human cytomegalovirus (HCMV) infection. Monocytes play a pivotal role in viral dissemination to organ tissue during primary infection and following reactivation from latency. For example, during primary infection, infected monocytes migrate into tissues and differentiate into macrophages, which then become a source of viral replication. In addition, because differentiated macrophages can survive for months to years, they provide a potential persistent infection source in various organ systems. We broadly note that there are three phases to infection and differentiation of HCMV-infected monocytes: (1) Virus enters and traffics to the nucleus through a virus receptor ligand engagement event that activates a unique signalsome that initiates the monocyte-to-macrophage differentiation process. (2) Following initial infection, HCMV undergoes a "quiescence-like state" in monocytes lasting for several weeks and promotes monocyte differentiation into macrophages. While, the initial event is triggered by the receptor-ligand engagement, the long-term cellular activation is maintained by chronic viral-mediated signaling events. (3) Once HCMV infected monocytes differentiate into macrophages, the expression of immediate early viral (IE) genes is detectable, followed by viral replication and long term infectious viral particles release. Herein, we review the detailed mechanisms of each phase during infection and differentiation into macrophages and discuss the biological significance of the differentiation of monocytes in the pathogenesis of HCMV.

Influenza virus and atherosclerosis

Influenza viruses infect the upper respiratory system, causing usually a self-limited disease with mild respiratory symptoms. Acute lung injury, pulmonary microvascular leakage and cardiovascular collapse may occur in severe cases, usually in the elderly or in immunocompromised patients. Acute lung injury is a syndrome associated with pulmonary oedema, hypoxaemia and respiratory failure. Influenza virus primarily binds to the epithelium, interfering with the epithelial sodium channel function. However, the main clinical devastating effects are caused by endothelial dysfunction, thought to be the main mechanism leading to pulmonary oedema, respiratory failure and cardiovascular collapse. A significant association was found between influenza infection and acute myocardial infarction (AMI). The incidence of admission due to AMI during an acute viral infection was six times as high during the 7 days after laboratory confirmation of influenza infection as during the control interval (10-fold in influenza B, 5-fold in influenza A, 3.5-fold in respiratory syncytial virus and 2.7-fold for all other viruses). Our review will focus on the mechanisms responsible for endothelial dysfunction during influenza infection leading to cardiovascular collapse and death.

Association of Cytomegalovirus DNA and Immunologic Markers of Cardiovascular Disease

BACKGROUND

Persons living with human immunodeficiency virus (HIV) (PLWH) with high cytomegalovirus (CMV)-specific interferon (IFN) γ response have increased numbers of endothelium homing receptor (CX3CR1)+-expressing cells that are associated with cardiovascular disease. The current study was performed to investigate the effect of cellular levels of CMV DNA on these markers.

METHODS

Eighty paired peripheral blood mononuclear cell samples were collected ≥12 months apart from 40 CMV-seropositive PLWH with suppressed HIV RNA, who started antiretroviral therapy at median of 3-months of infection. The samples were assessed for CMV-specific IFN-γ response by means of enzyme-linked immunospot assay, and participants were classified as low responders (LRs) or high responders (HRs) based on IFN-γ production (≤100 or >100 spot-forming units [SFUs]/105 cells).

RESULTS

Of the 40 participants, 26 (65%) were HRs and 14 (35%) LRs at baseline, which did not change over time or by CMV levels (median at first/second time points, 383/308 SFUs/106 cells for HRs vs 21/41 SFUs/106 for LRs). A decrease in IFN-γ over time was associated with higher CMV DNA levels (P < .01). High CMV response was also associated with increased CD28+CD27-CD4+ T cells expressing CX3CR1 (P < .001). Similarly, increased IFN-γ production was associated with increased CMV-specific CX3CR1+CD28+CD27-CD4+ and CD8+ T cells (P < .001).

CONCLUSIONS

These findings demonstrate that levels of CMV-specific IFN-γ response in PLWH are stable over time, and that HRs have increased circulating T cells expressing CX3CR1 that may put them at increased risk of cardiovascular disease and other inflammatory diseases.

Role of vasodilator-stimulated phosphoprotein in human cytomegalovirus-induced hyperpermeability of human endothelial cells

Atherosclerosis (AS) is a common chronic vascular disease and epidemiological evidence demonstrates that infection is closely associated with the occurrence of AS, including infection by human cytomegalovirus (HCMV) and Chlamydophila pneumoniae. The aim of the present study was to investigate the effect of HCMV AD169 infection on the barrier function of human umbilical vein endothelial cells (HUVECs) and to understand the role of vasodilator-stimulated phosphoprotein (VASP) during this process. In cultured HUVEC-CRL-1730 cells, knockdown of VASP expression with small interfering (si)RNA-VASP resulted in impaired cellular barrier function. Furthermore, knockdown of Ras-related C3 botulinum toxin substrate 1 (Rac1) using siRNA-Rac1 could induce downregulation of VASP expression in HUVEC-CRL-1730 cells. Additionally, following the infection of the cells by HCMV, cellular morphological alterations could be observed under an inverted microscope, the mRNA and protein levels of Rac1 and VASP were transiently reduced, and what appeared to be a time-dependent impairment of the barrier function was observed. Finally, transfection of siRNA-VASP or siRNA-Rac1 into HCMV-infected HUVEC-CRL-1730 cells resulted in increased impairment of the cellular barrier function. Taken together, these data demonstrated that HCMV infection could induce impairment of the barrier function in monolayer HUVEC-CRL-1730 cells via interference with Rac1/VASP expression.

Anti-cytomegalovirus IgG antibody titer is positively associated with advanced T cell differentiation and coronary artery disease in end-stage renal disease

Background

Accumulating evidence indicates that persistent human cytomegalovirus (HCMV) infection is associated with several health-related adverse outcomes including atherosclerosis and premature mortality in individuals with normal renal function. Patients with end-stage renal disease (ESRD) exhibit impaired immune function and thus may face higher risk of HCMV-related adverse outcomes. Whether the level of anti-HCMV immune response may be associated with the prognosis of hemodialysis patients is unknown.

Results

Among 412 of the immunity in ESRD study (iESRD study) participants, 408 were HCMV seropositive and were analyzed. Compared to 57 healthy individuals, ESRD patients had higher levels of anti-HCMV IgG. In a multivariate-adjusted logistic regression model, the log level of anti-HCMV IgG was independently associated with prevalent coronary artery disease (OR = 1.93, 95% CI = 1.2~ 3.2, p = 0.01) after adjusting for age, sex, hemoglobin, diabetes, calcium phosphate product and high sensitivity C-reactive protein. Levels of anti-HCMV IgG also positively correlated with both the percentage and absolute number of terminally differentiated CD8+ and CD4+ CD45RA+ CCR7- T_EMRA cells, indicating that immunosenescence may participate in the development of coronary artery disease.

Conclusion

This is the first study showing that the magnitude of anti-HCMV humoral immune response positively correlates with T cell immunosenescence and coronary artery disease in ESRD patients. The impact of persistent HCMV infection should be further investigated in this special patient population.

Electronic supplementary material

The online version of this article (10.1186/s12979-018-0120-0) contains supplementary material, which is available to authorized users.

Venous Thrombosis Secondary to Acute Cytomegalovirus Infection in an Immunocompetent Host: Consideration for New Screening Guidelines

Serious thrombotic complications associated with an acute cytomegalovirus (CMV) infection in immunocompromised and immunocompetent patients are becoming increasingly recognized. While typically asymptomatic and self-limiting, an acute CMV infection appears to demonstrate a rare propensity for a vascular thrombosis, such as deep vein thrombosis (DVT), thrombophlebitis, and pulmonary embolism (PE). It remains unclear whether other predisposing factors play a role in its pathogenesis. We report the case of a young, immunocompetent male with extensive lower extremity DVT who was coincidentally found to be CMV-immunoglobulin M (IgM) seropositive. In light of the increasing prevalence of CMV-associated thrombotic events, we reviewed the current literature on its incidence, pathophysiology, clinical features, and thrombophilia screening to consider the possibility of CMV seropositivity as an independent risk factor for vascular events. This may have repercussions for screening guidelines and preventive strategies in those with active CMV infection.

Cytomegalovirus Infection and Relative Risk of Cardiovascular Disease (Ischemic Heart Disease, Stroke, and Cardiovascular Death): A Meta-Analysis of Prospective Studies Up to 2016

BACKGROUND

Several studies have suggested that cytomegalovirus infection is likely associated with an increased relative risk of cardiovascular disease (CVD); however, the results are inconsistent. We aimed to provide a systematic review and meta-analysis of community-based prospective studies assessing the association between cytomegalovirus infection and relative risk of CVD.

METHODS AND RESULTS

We searched Medline and EMBASE to retrieve prospective studies that reported risk estimates of the association between cytomegalovirus infection and relative risk of CVD. The search yielded 10 articles including a total of 34 564 participants and 4789 CVD patients. Overall, exposure to cytomegalovirus infection was associated with a 22% (relative risk: 1.22, 95% CI: 1.07-1.38, P=0.002) increased relative risk of future CVD. We estimated that 13.4% of CVD incidence could be attributable to cytomegalovirus infection.

CONCLUSIONS

In conclusion, cytomegalovirus infection is associated with a significantly increased relative risk of CVD.

An Unsettled Debate About the Potential Role of Infection in Pathogenesis of Atherosclerosis

Association of infection with atherosclerosis is by no means new. Several sero-epidemiological and pathologic studies as well as animal models have shown a link between infection and atherosclerosis. Exciting discoveries in recent times related to role of inter-individual genetic variation in modulating inflammatory response to infection have reignited the enthusiasm in proving a causal link between infection and atherosclerosis. The purpose of this article was to review and analyze the available evidence linking infection with atherosclerosis.

Positive Expression of Human Cytomegalovirus Phosphoprotein 65 in Atherosclerosis

Previous studies showed that human cytomegalovirus (HCMV) is associated with atherosclerosis. However, local vascular atherosclerosis related HCMV infection and protein expression remain unclear. This study aimed to assess the relationship between HCMV infection and atherosclerosis. Formalin-fixed, paraffin-embedded peripheral artery specimens were obtained from 15 patients with atherosclerosis undergoing vascular surgery from 2008 to 2010 at Zhongnan Hospital, Wuhan University. Pathological analyses were carried out after hematoxylin and eosin (H&E) and Masson trichrome staining. In situ hybridization and immunohistochemistry with two different monoclonal antibodies were employed to detect HCMV nucleic acids and proteins, respectively. H&E and Masson trichrome staining showed homogeneous extracellular matrix in femoral artery, while smooth muscle fibers were interlaced with collagen fibers; in carotid artery, inflammatory cell infiltration, foam cell vascular change, cholesterol crystals, and layered collagen fibers were observed. In situ hybridization showed no expression of HCMV nucleic acids in all 15 cases. Immunohistochemical staining for protein immediate-early protein (IE1 72) was negative in all cases, while phosphoprotein 65 (pp65) expression was detected in 14 cases. A high rate of positive pp65 signals was found in patients with atherosclerosis, suggesting that local HCMV infection may be associated with the pathogenesis of atherosclerosis. Further studies on this relationship are warranted.

The Cell Biology of Cytomegalovirus: Implications for Transplantation

Interpretation of clinical data regarding the impact of cytomegalovirus (CMV) infection on allograft function is complicated by the diversity of viral strains and substantial variability of cellular receptors and viral gene expression in different tissues. Variation also exists in nonspecific (monocytes and dendritic cells) and specific (NK cells, antibodies) responses that augment T cell antiviral activities. Innate immune signaling pathways and expanded pools of memory NK cells and γδ T cells also serve to amplify host responses to infection. The clinical impact of specific memory T cell anti-CMV responses that cross-react with graft antigens and alloantigens is uncertain but appears to contribute to graft injury and to the abrogation of allograft tolerance. These responses are modified by diverse immunosuppressive regimens and by underlying host immune deficits. The impact of CMV infection on the transplant recipient reflects cellular changes and corresponding host responses, the convergence of which has been termed the "indirect effects" of CMV infection. Future studies will clarify interactions between CMV infection and allograft injury and will guide interventions that may enhance clinical outcomes in transplantation.

P-TEFb goes viral

Positive transcription elongation factor b (P‐TEFb), which comprises cyclin‐dependent kinase 9 (CDK9) kinase and cyclin T subunits, is an essential kinase complex in human cells. Phosphorylation of the negative elongation factors by P‐TEFb is required for productive elongation of transcription of protein‐coding genes by RNA polymerase II (pol II). In addition, P‐TEFb‐mediated phosphorylation of the carboxyl‐terminal domain (CTD) of the largest subunit of pol II mediates the recruitment of transcription and RNA processing factors during the transcription cycle. CDK9 also phosphorylates p53, a tumor suppressor that plays a central role in cellular responses to a range of stress factors. Many viral factors affect transcription by recruiting or modulating the activity of CDK9. In this review, we will focus on how the function of CDK9 is regulated by viral gene products. The central role of CDK9 in viral life cycles suggests that drugs targeting the interaction between viral products and P‐TEFb could be effective anti‐viral agents.

Synthetic DNA approach to cytomegalovirus vaccine/immune therapy

There is no licensed vaccine or cure for human cytomegalovirus (CMV), a ubiquitous β-herpes virus that infects 60-95 % of adults worldwide. Infection is a major cause of congenital abnormalities in newborns, contributes to development of childhood cerebral palsy and medulloblastoma, can result in severe disease in immunocompromised patients, and is a major impediment during successful organ transplantation. While CMV has been increasingly associated with numerous inflammatory diseases and cancers, only recently has it been correlated with increased risk of heart disease in adults, the number-one killer in the USA. These data, among others, suggest that subclinical CMV infection, or microinfection, in healthy individuals may play more of a causative role than an epiphenomenon in development of CMV-associated pathologies. Due to the myriad of diseases and complications associated with CMV, an efficacious vaccine would be highly valuable in reducing human morbidity and mortality as well as saving billions of dollars in annual health-care costs and disability adjusted life years (DALY) in the developing world. Therefore, the development of a safe efficacious CMV vaccine or immune therapy is paramount to the public health. This review aims to provide a brief overview on aspects of CMV infection and disease and focuses on current vaccine strategies. The use of new synthetic DNA vaccines might offer one such approach to this difficult problem.

Human Cytomegalovirus UL135 and UL136 Genes Are Required for Postentry Tropism in Endothelial Cells

Endothelial cells (ECs) are a critical target of viruses, and infection of the endothelium represents a defining point in viral pathogenesis. Human cytomegalovirus (HCMV), the prototypical betaherpesvirus, encodes proteins specialized for entry into ECs and delivery of the genome to the nuclei of ECs. Virus strains competent to enter ECs replicate with differing efficiencies, suggesting that the virus encodes genes for postentry tropism in ECs. We previously reported a specific requirement for the UL133/8 locus of HCMV for replication in ECs. The UL133/8 locus harbors four genes: UL133, UL135, UL136, and UL138. In this study, we find that while UL133 and UL138 are dispensable for replication in ECs, both UL135 and UL136 are important. These genes are not required for virus entry or the expression of viral genes. The phenotypes associated with disruption of either gene reflect phenotypes observed for the UL133/8NULL virus, which lacks the entire UL133/8 locus, but are largely distinct from one another. Viruses lacking UL135 fail to properly envelop capsids in the cytoplasm, produce fewer dense bodies (DB) than the wild-type (WT) virus, and are unable to incorporate viral products into multivesicular bodies (MVB). Viruses lacking UL136 also fail to properly envelop virions and produce larger dense bodies than the WT virus. Our results indicate roles for the UL135 and UL136 proteins in commandeering host membrane-trafficking pathways for virus maturation. UL135 and UL136 represent the first HCMV genes crucial for early- to late-stage tropism in ECs.

IMPORTANCE

Human cytomegalovirus (HCMV) persists in the majority of the world's population. While typically asymptomatic in healthy hosts, HCMV can cause significant morbidity and mortality in immunocompromised or naïve individuals, particularly transplant patients and patients with congenital infections, respectively. Lifelong persistence of the virus may also contribute to age-related pathologies, such as vascular disease. One aspect of HCMV infection contributing to complex and varied pathogenesis is the diverse array of cell types that this virus infects in the host. The vascular endothelium is a particularly important target of infection, contributing to viral dissemination and likely leading to CMV complications following transplantation. In this work, we identify two viral gene products required for postentry tropism in endothelial cells. Identifying tropism factors required for replication in critical cell targets of infection is important for the development of strategies to restrict virus replication.

Helicobacter pylori gastritis, a presequeale to coronary plaque

Helicobacter pylori are considered the most common human pathogen colonizing gastric mucosa. Gastritis with or without H. pylori infection is associated with increase in levels of homocysteine and high-sensitivity C-reactive protein (hs-CRP) but a more pronounced increase is noted in gastritis with H. pylori infection. Increasing level of homocysteine, due to decreased absorption of vitamin B₁₂ and folic acid, together with increased CRP levels in gastritis with H. pylori infection may be the earliest event in the process of atherosclerosis and plaque formation. Retrospective study conducted at tertiary care hospital in Mumbai by Department of Biochemistry in association with Department of Surgery. Eighty patients who underwent gastroscopy in view of gastritis were subjected to rapid urease test for diagnosis of H. pylori infection. Vitamin B₁₂, folic acid, homocysteine and hs-CRP were analyzed using chemiluminescence immuno assay. Student’s t-test, Pearson’s correlation and linear regression used for statistical analysis.

Patients with H. pylori gastritis had significantly lower levels of vitamin B₁₂ (271.6±101.3 vs 390.6±176.7 pg/mL; P=0.0005), as well as higher levels of homocysteine (17.4±7.4 vs 13.8±7.8 µmol/L; P=0.037) and hs-CRP (2.5±2.9 vs 1.2±1.1 mg/L; P=0.017), than in patients without H. pylori gastritis. However, folic acid showed (8.9±3.2 vs 10.0±3.6 ng/mL; P=0.171) no significant difference.

Elevated homocysteine and hs-CRP in H. pylori gastritis may independently induce endothelial dysfunction, leading to cardiovascular pathology.

Differential Effects of IFN-β on the Survival and Growth of Human Vascular Smooth Muscle and Endothelial Cells

It has been documented that interferon (IFN)-β is effective against the genesis of atherosclerosis or hyperplastic arterial disease in animal model. The main mechanism of the efficacy was antiproliferative action on the growth of vascular smooth muscle cells (SMC). To understand more about the mechanisms that are responsible for the efficacy, we examined minutely the effects of IFN-β on the apoptosis and growth of vascular SMC and endothelial cells (EC). IFN-β enhanced SMC apoptosis in serum starved medium. Conversely, EC apoptosis induced by serum and growth factor deprivation was inhibited by IFN-β. The induction of SMC apoptosis and anti-apoptotic effect on EC linked to the expression of pro-apoptotic bax mRNA and caspase-3 activities. Anti-apoptotic bcl-2 mRNA was also up-regulated in EC. IFN-β inhibited SMC growth in a dose dependent manner. However, the growth of EC was rather enhanced by a low dose of IFNs. The antiproliferative effect on SMC associated with the activation of p21 and increase of G0/G1 arrested cells. The growth stimulation on EC was considered to link with increase of S and G2/M phase cells. SMC produced IFN-β in response to various stimulants. However, IFN-β was not induced in EC. These suggested that endogenous IFN-β from SMC may act on EC and affect to EC functions. In this study, it was clarified that IFN-β enhances SMC apoptosis and inhibits the EC apoptosis, and stimulates the EC growth. These effects were considered to contribute to a cure against hyperplastic arterial diseases as the mechanisms in the efficacy of IFN-β.

Variants for HDL-C, LDL-C, and triglycerides identified from admixture mapping and fine-mapping analysis in African American families

BACKGROUND

Admixture mapping of lipids was followed-up by family-based association analysis to identify variants for cardiovascular disease in African Americans.

METHODS AND RESULTS

The present study conducted admixture mapping analysis for total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. The analysis was performed in 1905 unrelated African American subjects from the National Heart, Lung and Blood Institute's Family Blood Pressure Program (FBPP). Regions showing admixture evidence were followed-up with family-based association analysis in 3556 African American subjects from the FBPP. The admixture mapping and family-based association analyses were adjusted for age, age(2), sex, body mass index, and genome-wide mean ancestry to minimize the confounding caused by population stratification. Regions that were suggestive of local ancestry association evidence were found on chromosomes 7 (low-density lipoprotein cholesterol), 8 (high-density lipoprotein cholesterol), 14 (triglycerides), and 19 (total cholesterol and triglycerides). In the fine-mapping analysis, 52 939 single-nucleotide polymorphisms (SNPs) were tested and 11 SNPs (8 independent SNPs) showed nominal significant association with high-density lipoprotein cholesterol (2 SNPs), low-density lipoprotein cholesterol (4 SNPs), and triglycerides (5 SNPs). The family data were used in the fine-mapping to identify SNPs that showed novel associations with lipids and regions, including genes with known associations for cardiovascular disease.

CONCLUSIONS

This study identified regions on chromosomes 7, 8, 14, and 19 and 11 SNPs from the fine-mapping analysis that were associated with high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides for further studies of cardiovascular disease in African Americans.

Comprehensive Review in Current Developments of Benzimidazole-Based Medicinal Chemistry

The properties of benzimidazole and its derivatives have been studied over more than one hundred years. Benzimidazole derivatives are useful intermediates/subunits for the development of molecules of pharmaceutical or biological interest. Substituted benzimidazole derivatives have found applications in diverse therapeutic areas such as antiulcer, anticancer agents, and anthelmintic species to name just a few. This work systematically gives a comprehensive review in current developments of benzimidazole-based compounds in the whole range of medicinal chemistry as anticancer, antibacterial, antifungal, anti-inflammatory, analgesic agents, anti-HIV, antioxidant, anticonvulsant, antitubercular, antidiabetic, antileishmanial, antihistaminic, antimalarial agents, and other medicinal agents. This review will further be helpful for the researcher on the basis of substitution pattern around the nucleus with an aim to help medicinal chemists for developing an SAR on benzimidazole drugs/compounds.

Human cytomegalovirus pUL79 is an elongation factor of RNA polymerase II for viral gene transcription

In this study, we have identified a unique mechanism in which human cytomegalovirus (HCMV) protein pUL79 acts as an elongation factor to direct cellular RNA polymerase II for viral transcription during late times of infection. We and others previously reported that pUL79 and its homologues are required for viral transcript accumulation after viral DNA synthesis. We hypothesized that pUL79 represented a unique mechanism to regulate viral transcription at late times during HCMV infection. To test this hypothesis, we analyzed the proteome associated with pUL79 during virus infection by mass spectrometry. We identified both cellular transcriptional factors, including multiple RNA polymerase II (RNAP II) subunits, and novel viral transactivators, including pUL87 and pUL95, as protein binding partners of pUL79. Co-immunoprecipitation (co-IP) followed by immunoblot analysis confirmed the pUL79-RNAP II interaction, and this interaction was independent of any other viral proteins. Using a recombinant HCMV virus where pUL79 protein is conditionally regulated by a protein destabilization domain ddFKBP, we showed that this interaction did not alter the total levels of RNAP II or its recruitment to viral late promoters. Furthermore, pUL79 did not alter the phosphorylation profiles of the RNAP II C-terminal domain, which was critical for transcriptional regulation. Rather, a nuclear run-on assay indicated that, in the absence of pUL79, RNAP II failed to elongate and stalled on the viral DNA. pUL79-dependent RNAP II elongation was required for transcription from all three kinetic classes of viral genes (i.e. immediate-early, early, and late) at late times during virus infection. In contrast, host gene transcription during HCMV infection was independent of pUL79. In summary, we have identified a novel viral mechanism by which pUL79, and potentially other viral factors, regulates the rate of RNAP II transcription machinery on viral transcription during late stages of HCMV infection.

In this study, we report a novel mechanism used by human cytomegalovirus (HCMV) to regulate the elongation rate of RNA polymerase II (RNAP II) to facilitate viral transcription during late stages of infection. Recently, we and others have identified several viral factors that regulate gene expression during late infection. These factors are functionally conserved among beta- and gamma- herpesviruses, suggesting a unique transcriptional regulation shared by viruses of these two subfamilies. However, the mechanism remains elusive. Here we show that HCMV pUL79, one of these factors, interacts with RNAP II as well as other viral factors involved in late gene expression. We have started to elucidate the nature of the pUL79-RNAP II interaction, finding that pUL79 does not alter the protein levels of RNAP II or its recruitment to viral promoters. However, during late times of infection, pUL79 helps RNAP II efficiently elongate along the viral DNA template to transcribe HCMV genes. Host genes are not regulated by this pUL79-mediated mechanism. Therefore, our study discovers a previously uncharacterized mechanism where RNAP II activity is modulated by viral factor pUL79, and potentially other viral factors as well, for coordinated viral transcription.

The impact of hepatitis C infection on ischemic heart disease via ischemic electrocardiogram

BACKGROUND

Hepatitis C virus (HCV) infection is a serious disease worldwide and it leads to several serious hepatic sequels. Some studies find possible correlation between HCV and ischemic heart disease in retrospective observations. Based on lacked community-based evidence, the study aims to assess correlation between ischemic heart disease and chronic HCV infection via electrocardiogram (ECG) because its abnormalities is strongly associating with cardiovascular disease mortality.

METHODS

The population was from one community health examination in December 2010 in a southern village of Taiwan. A total of 9856 participants were evaluated and finally 5015 eligible residents with age older than 40 years were included. The baseline characteristics and laboratory data in nonischemic ECG and ischemic ECG groups were compared, and multivariate-adjusted analysis was used to evaluate the risks to ischemic ECG.

RESULTS

The higher prevalence of hypertension, metabolic syndrome and even HCV infection (25.3% versus 11.6%; P < 0.001) in ischemic ECG group than those in nonischemic ECG group. In the multivariate adjusted analysis, HCV infection would lead to a 1.759-fold risk to ischemic ECG when compared with non-HCV subjects.

CONCLUSIONS

HCV was strongly associated with ischemic ECG findings in this community study, and it could be a nonconventional risk factor for coronary artery disease.

Myopericarditis complicated by pulmonary embolism in an immunocompetent patient with acute cytomegalovirus infection: a case report

Background

Primary acute cytomegalovirus infection in immunocompetent patients is common worldwide. Infection is most often asymptomatic or occurs sub-clinically with a self-limited mononucleosis-like syndrome. More rarely, the infection may lead to severe organ complications with pneumonia, myocarditis, pericarditis, colitis and hemolytic anemia. Recent cases of cytomegalovirus-associated thrombosis have also been reported sporadically in the medical literature.

Case presentation

We report here a case of simultaneous myopericarditis and pulmonary embolism in a 30-year-old man with no medical history. The patient was not immunocompromised. We discuss the possible role of acute cytomegalovirus infection in the induction of vascular damage and review relevant cases in the literature.

Conclusion

Thrombosis in patients with acute cytomegalovirus infection may be more frequent than is generally thought. Physicians need to be aware of the possible association between acute cytomegalovirus and thrombosis in immunocompetent patients, especially in the presence of severe systemic infection, as our case illustrates.

Atherosclerosis and Alzheimer--diseases with a common cause? Inflammation, oxysterols, vasculature

BACKGROUND

Aging is accompanied by increasing vulnerability to pathologies such as atherosclerosis (ATH) and Alzheimer disease (AD). Are these different pathologies, or different presentations with a similar underlying pathoetiology?

DISCUSSION

Both ATH and AD involve inflammation, macrophage infiltration, and occlusion of the vasculature. Allelic variants in common genes including APOE predispose to both diseases. In both there is strong evidence of disease association with viral and bacterial pathogens including herpes simplex and Chlamydophila. Furthermore, ablation of components of the immune system (or of bone marrow-derived macrophages alone) in animal models restricts disease development in both cases, arguing that both are accentuated by inflammatory/immune pathways. We discuss that amyloid β, a distinguishing feature of AD, also plays a key role in ATH. Several drugs, at least in mouse models, are effective in preventing the development of both ATH and AD. Given similar age-dependence, genetic underpinnings, involvement of the vasculature, association with infection, Aβ involvement, the central role of macrophages, and drug overlap, we conclude that the two conditions reflect different manifestations of a common pathoetiology.

MECHANISM

Infection and inflammation selectively induce the expression of cholesterol 25-hydroxylase (CH25H). Acutely, the production of 'immunosterol' 25-hydroxycholesterol (25OHC) defends against enveloped viruses. We present evidence that chronic macrophage CH25H upregulation leads to catalyzed esterification of sterols via 25OHC-driven allosteric activation of ACAT (acyl-CoA cholesterol acyltransferase/SOAT), intracellular accumulation of cholesteryl esters and lipid droplets, vascular occlusion, and overt disease.

SUMMARY

We postulate that AD and ATH are both caused by chronic immunologic challenge that induces CH25H expression and protection against particular infectious agents, but at the expense of longer-term pathology.

Chemokines in atherosclerosis: proceedings resumed

Chemokines play important roles in atherosclerotic vascular disease. Expressed by not only cells of the vessel wall but also emigrated leukocytes, chemokines were initially discovered to direct leukocytes to sites of inflammation. However, chemokines can also exert multiple functions beyond cell recruitment. Here, we discuss novel and recently emerging aspects of chemokines and their involvement in atherosclerosis. While reviewing newly identified roles of chemokines and their receptors in monocyte and neutrophil recruitment during atherogenesis and atheroregression, we also revisit homeostatic functions of chemokines, including their roles in cell homeostasis and foam cell formation. The functional diversity of chemokines in atherosclerosis warrants a clear-cut mechanistic dissection and stage-specific assessment to better appreciate the full scope of their actions in vascular inflammation and to identify pathways that harbor the potential for a therapeutic targeting of chemokines in atherosclerosis.

Overview of human cytomegalovirus pathogenesis

Human cytomegalovirus (HCMV) is a human pathogen that infects greater than 50 % of the human population. HCMV infection is usually asymptomatic in most individuals. That is, primary infection or reactivation of latent virus is generally clinically silent. HCMV infection, however, is associated with significant morbidity and mortality in the immunocompromised and chronic inflammatory diseases in the immunocompetent. In immunocompromised individuals (acquired immune deficiency syndrome and transplant patients, developing children (in utero), and cancer patients undergoing chemotherapy), HCMV infection increases morbidity and mortality. In those individuals with a normal immune system, HCMV infection is also associated with a risk of serious disease, as viral infection is now considered to be a strong risk factor for the development of various vascular diseases and to be associated with some types of tumor development. Intense research is currently being undertaken to better understand the mechanisms of viral pathogenesis that are briefly discussed in this chapter.

Synthesis and anti-HCMV activity of 1-[ω-(phenoxy)alkyl]uracil derivatives and analogues thereof

HCMV infection represents a life-threatening condition for immunocompromised patients and newborn infants and novel anti-HCMV agents are clearly needed. In this regard, a series of 1-[ω-(phenoxy)alkyl]uracil derivatives were synthesized and examined for antiviral properties. Compounds 17, 20, 24 and 28 were found to exhibit highly specific and promising inhibitory activity against HCMV replication in HEL cell cultures with EC50 values within 5.5-12μM range. Further studies should be undertaken to elucidate the mechanism of action of these compounds and the structure-activity relationship for the linker region.

Sirolimus and cardiovascular disease risk in liver transplantation

BACKGROUND

Two adverse effects of sirolimus are hypertriglyceridemia and hypercholesterolemia. These elevated levels often lead clinicians to discontinue the sirolimus from concerns of an increased cardiovascular disease (CVD) risk; however, evidence suggests that sirolimus might be cardioprotective. There are no published reports of sirolimus CVD in liver transplantation.

METHODS

We reviewed all 1812 liver recipients who underwent transplantation from 1998 to 2010, identifying a cohort using sirolimus as part of the initial immunosuppression (SRL Cohort) and a control group of the remaining patients from this period where SRL was never given (Non-SRL Control). A prospectively maintained database identified all episodes of myocardial infarction (MI), congestive heart failure (CHF), abdominal aortic aneurysm (AAA), and cerebrovascular accident and tracked triglyceride, high-density and low-density lipoproteins, and total cholesterol levels. A Framingham Risk Model calculated the predicted 10-year risk of CVD for both groups.

RESULTS

The SRL Cohort (n=406) is older, more predominantly male, with more pretransplantation hypertension and diabetes and posttransplantation hypertension compared to Non-SRL Controls (n=1005). The SRL Cohort has significantly higher triglyceride, low-density lipoprotein, and cholesterol levels at 6 months and 1 year. There is no difference in MI incidence in the SRL Cohort (1.0% vs. 1.2%) and no difference in AAA, cerebrovascular accident, and CHF. The Framingham Risk Model predicts that the SRL Cohort should have almost double the 10-year risk of CVD compared to the Non-SRL Control (11% vs. 6%).

CONCLUSIONS

Sirolimus causes hypertriglyceridemia and hypercholesterolemia, but it does not increase the incidence of MI or other CVDs. Considering the SRL Cohort has more cardiac risk factors and nearly double 10-year predicted CVD risk, the fact that the CVD incidence is similar suggests that sirolimus is in fact cardioprotective.

An endothelial cell-specific requirement for the UL133-UL138 locus of human cytomegalovirus for efficient virus maturation

Human cytomegalovirus (HCMV) infects a variety of cell types in humans, resulting in a varied pathogenesis in the immunocompromised host. Endothelial cells (ECs) are considered an important target of HCMV infection that may contribute to viral pathogenesis. Although the viral determinants important for entry into ECs are well defined, the molecular determinants regulating postentry tropism in ECs are not known. We previously identified the UL133-UL138 locus encoded within the clinical strain-specific ULb' region of the HCMV genome as important for the latent infection in CD34(+) hematopoietic progenitor cells (HPCs). Interestingly, this locus, while dispensable for replication in fibroblasts, was required for efficient replication in ECs infected with the TB40E or fusion-inducing factor X (FIX) HCMV strains. ECs infected with a virus lacking the entire locus (UL133-UL138(NULL) virus) complete the immediate-early and early phases of infection but are defective for infectious progeny virus production. ECs infected with UL133-UL138(NULL) virus exhibited striking differences in the organization of intracellular membranes and in the assembly of mature virions relative to ECs infected with wild-type (WT) virus. In UL133-UL138(NULL) virus-infected ECs, Golgi stacks were disrupted, and the viral assembly compartment characteristic of HCMV infection failed to form. Further, progeny virions in UL133-UL138(NULL) virus-infected ECs inefficiently acquired the virion tegument and secondary envelope. These defects were specific to infection in ECs and not observed in fibroblasts infected with UL133-UL138(NULL) virus, suggesting an EC-specific requirement for the UL133-UL138 locus for late stages of replication. To our knowledge, the UL133-UL138 locus represents the first cell-type-dependent, postentry tropism determinant required for viral maturation.

Vaccination with synthetic constructs expressing cytomegalovirus immunogens is highly T cell immunogenic in mice

There is no licensed vaccine or cure for human cytomegalovirus (CMV), a ubiquitous β-herpesvirus infecting 60-95% of adults worldwide. Infection can cause congenital abnormalities, result in severe disease in immunocompromised patients, and is a major impediment during successful organ transplantation. In addition, it has been associated with numerous inflammatory diseases and cancers, as well as being implicated in the development of essential hypertension, a major risk factor for heart disease. To date, limited data regarding the identification of immunogenic viral targets has frustrated CMV vaccine development. Based upon promising clinical data suggesting an important role for T cells in protecting against disease in the transplantation setting, we designed a novel panel of highly-optimized synthetic vaccines encoding major CMV proteins and evaluated their immune potential in murine studies. Vaccination induced robust CD8+ and CD4+ T cells of great epitopic breadth as extensively analyzed using a novel modified T cell assay described herein. Together with improved levels of CMV-specific T cells as driven by a vaccine, further immune evaluation of each target is warranted. The present model provides an important tool for guiding future immunization strategies against CMV.

Human cytomegalovirus linked to stroke in a Chinese population

AIM

Human cytomegalovirus (HCMV) is implicated in several cardiovascular disorders, including atherosclerosis, coronary heart disease, and cardiac transplant arteriopathy. We aimed to evaluate the relationship between HCMV and stroke.

METHODS

Real-time polymerase chain reaction (PCR) and ELISA were performed on plasma samples isolated from 200 patients diagnosed with stroke and 200 controls. All participants belonged to the Stroke Hypertension Investigation in Genetics (SHINING) study.

RESULTS

HCMV seropositivity was higher in the stroke group than in controls (55.0% vs. 23.5%; P < 0.0001). The presence of HCMV DNA increased the risk of stroke (unadjusted odds ratio [OR], 3.98; 95% confidence interval [CI], 2.59 to 6.11; P < 0.0001). Risks were also increased for the subtypes ischemic stroke (unadjusted OR, 4.01; 95% CI, 2.57-6.24; P < 0.0001) and hemorrhagic stroke (unadjusted OR, 3.80; 95% CI, 1.64-8.78; P= 0.0018). Increased risk with HCMV remained significant after adjustment for age, sex, body mass index, hypertension, and smoking (ischemic stroke: adjusted OR, 4.07; 95% CI, 2.52-6.32; P < 0.0001; hemorrhagic stroke: adjusted OR, 3.88; 95% CI, 1.61-9.36; P= 0.0026).

CONCLUSIONS

We demonstrate a novel link between HCMV infection and stroke. These findings may provide important insights into the pathogenesis of stroke.

Higher immunoglobulin G antibody levels against cytomegalovirus are associated with incident ischemic heart disease in the population-based EPIC-Norfolk cohort

BACKGROUND

Cytomegalovirus (CMV) is associated with ischemic heart disease (IHD) among organ transplant recipients. The relationship between the levels of antibody for CMV with IHD in immunocompetent individuals is uncertain.

METHODS

We measured baseline CMV immunoglobulin G (IgG) levels in 12,574 participants without IHD from the population-based EPIC-Norfolk cohort, aged 40-70 years old at recruitment in 1993-1997. Underlying causes of death or hospitalization until 31 March 2008 were abstracted from death certificates and a database of hospital admissions, respectively.

RESULTS

Of the participants, 58% were seropositive for CMV. After a mean follow-up of 12 years (standard deviation, 2.2 years), 1356 first-time IHD events occurred. After adjustment for classic IHD risk factors, belonging to the highest antibody group was associated with an increased risk of incident IHD, compared with seronegativity (hazard ratio, 1.22; 95% confidence interval, 1.05-1.42). After additional adjustment for measures of social class, inflammation, and possible confounders, this association was unchanged (hazard ratio, 1.21; 95% confidence interval, 1.04-11.41).

CONCLUSIONS

This is the first population study to show that CMV IgG antibody levels are related to incident IHD compared to seronegativity. Studies correlating CMV antibody levels with direct measurements of active infection will be necessary.

Infection with cytomegalovirus is not associated with premature mortality

Over 90% of the world's population acquires a cytomegalovirus (CMV) infection. This infection, although asymptomatic or self-limiting, is a major burden to the immune system. For this reason, and because CMV immunization is possible, determining whether CMV can cause reduced longevity, particularly among those with coronary artery disease, is important and previous reports have been conflicting. Thus our objective was to assess the association between CMV infection as defined serologically and antibody levels against CMV and long-term survival (18 years). We completed a prospective observational cohort study of 915 consecutive patients (mean age 58 years) undergoing coronary angiography. CMV immunoglobulin levels were measured at baseline using either a whole cell CMV antigen or a purified protein antigen (gB). After adjustment for potentially confounding variables (age, race, gender, body mass index, the presence or absence of coronary artery disease, the number of diseased vessels, diabetes, renal disease, hypertension, dialysis, congestive heart failure, and the maximum percent reduction in luminal diameter), Cox's proportional hazards models showed no association between CMV seropositivity or levels of antibodies against CMV by either assay and longevity for both patients with or without coronary artery disease (CAD) nor for those under or over 70 years of age at baseline. Our observations suggest that universal immunization against CMV may not improve longevity.

Endothelial dysfunction is reversible in Helicobacter pylori-positive subjects

BACKGROUND

Studies have shown an association between Helicobacter pylori (HP) infection and atherosclerosis. Although epidemiological studies have suggested an association between HP infection and atherosclerosis, the issue is still controversial. It is not clear whether HP eradication will reverse endothelial damage and prevent cardiovascular events.

METHODS

Thirty-one dyspeptic subjects (16 men, 15 women; 50.8 ± 16.7 years) were diagnosed as HP positive using histopathological evaluation. Eleven dyspeptic subjects (5 men, 6 women; 55.4 ± 9.3 years) were negative to HP (controls). Interleukin-6 level and vascular measurements (ankle brachial index and flow-mediated diameter percent change) were done twice: on entry and 3 months afterwards. HP-positive subjects were treated with the triple therapy.

RESULTS

Thirty-one HP-positive subjects (50.8 ± 16.7 years, 16 men, weight 79.6 ± 14.8 kg, height 1.70 ± 0.1 m, body mass index [BMI] 27.5 ± 4.4, waist circumference 97.6 ± 16.7 cm) were treated accordingly. There were 11 HP-negative subjects (controls) (55.4 ± 9.3 years, 5 men, weight 83.4 ± 16.8 kg, height 1.68 ± 0.1 m, BMI 29.6 ± 6.1, waist circumference 104.4 ± 13.7 cm). No difference in age (P=.27), weight (P=.51), height (P=.50), BMI (P=.30), or waist circumference (P=.20) was observed. HP-positive subjects had severe endothelial dysfunction (-1.26 ± 8.4%) that improved after treatment (8.4 ± 9.0%) (P=.001). HP-negative subjects had endothelial dysfunction (1.9 ± 9.7%) that was not improved (5.6 ± 8.3%) (P=.41). Interleukin-6 levels in serum were not elevated in HP-positive subjects before or after HP eradication (8.4 ± 17.5 vs 13.5 ± 30.7 pg/mL; P=.45).

CONCLUSIONS

The novel finding of our study was that HP eradication can improve endothelial dysfunction.

Shedding light on the elusive role of endothelial cells in cytomegalovirus dissemination

Cytomegalovirus (CMV) is frequently transmitted by solid organ transplantation and is associated with graft failure. By forming the boundary between circulation and organ parenchyma, endothelial cells (EC) are suited for bidirectional virus spread from and to the transplant. We applied Cre/loxP-mediated green-fluorescence-tagging of EC-derived murine CMV (MCMV) to quantify the role of infected EC in transplantation-associated CMV dissemination in the mouse model. Both EC- and non-EC-derived virus originating from infected Tie2-cre(+) heart and kidney transplants were readily transmitted to MCMV-naïve recipients by primary viremia. In contrast, when a Tie2-cre(+) transplant was infected by primary viremia in an infected recipient, the recombined EC-derived virus poorly spread to recipient tissues. Similarly, in reverse direction, EC-derived virus from infected Tie2-cre(+) recipient tissues poorly spread to the transplant. These data contradict any privileged role of EC in CMV dissemination and challenge an indiscriminate applicability of the primary and secondary viremia concept of virus dissemination.

Malnutrition, infection and arteriovenous fistula failure: is there a link?

INTRODUCTION

The histology of neointimal hyperplasia, the primary cause of arteriovenous fistula (AVF) stenosis, resembles the histology of atherosclerosis. We evaluated classic atherogenic risk factors such as hypertension, smoking, diabetes, cholesterol, and evaluated the role of expanded risk factors such as: cytomegalovirus (CMV), Helicobacter pylori (H. pylori), Chlamydia pneumoniae (C. pneumoniae), infection, and malnutrition, as possible causes of AVF failure in hemodialysis (HD) patients.

METHODS

AVF of 91 HD patients were monitored by on-line blood flow measurement (Qac); levels of albumin, fibrinogen, C-reactive protein and plasma cholesterol were recorded. Nutrition was evaluated via the Malnutrition Inflammation Score and the normalized protein intake (nPCR). Seropositivity to CMV, C. pneumoniae and H. Pylori were assessed.

RESULTS

Twenty-one patients had at least one episode of vascular access thrombosis; 17 patients had stenotic lesions. Analysis of survival tables revealed that patients who had high IgG CMV antibody levels had a higher probability of AVF failure than patients with lower CMV antibody levels. The difference in the empirical survival functions was statistically significant when we stratified by CMV antibody levels, unlike H. pylori or C. pneumoniae. In a logistic regression model, CMV, increased cholesterol, and decreases in nPCR and Qac significantly increased the risk of AVF failure.

CONCLUSION

Our study suggests that CMV infection, total plasma cholesterol, decreased Qac, and nPCR are important risk factors of AVF failure in HD patients.

Signature microRNA expression profile of essential hypertension and its novel link to human cytomegalovirus infection

BACKGROUND

Essential hypertension has been recognized as a disease resulting from a combination of environmental and genetic factors. Recent studies demonstrated that microRNAs (miRNAs) are involved in cardiac hypertrophy and heart failure. However, little is known about the roles of miRNAs in essential hypertension.

METHODS AND RESULTS

Using microarray-based miRNA expression profiling, we compared the miRNA expressions in plasma samples from 13 hypertensive patients and 5 healthy control subjects. Twenty-seven miRNAs were found to be differentially expressed. The expressions of selected miRNAs (miR-296-5p, let-7e, and a human cytomegalovirus [HCMV]-encoded miRNA, hcmv-miR-UL112) were validated independently in plasma samples from 24 hypertensive patients and 22 control subjects. The absolute expression levels of hcmv-miR-UL112, miR-296-5p, and let-7e were further determined in 127 patients and 67 control subjects (fold changes are 2.5, 0.5, and 1.7 respectively; all P<0.0001). Additionally, we demonstrated that interferon regulatory factor 1 is a direct target of hcmv-miR-UL112. Increased HCMV seropositivity and quantitative titers were found in the hypertension group compared with the control group (52.7% versus 30.9%, P=0.0005; 1870 versus 54 copies per 1 mL plasma, P<0.0001). Seropositivity, log-transformed copies of HCMV, and hcmv-miR-UL112 were independently associated with an increased risk of hypertension (odds ratio, 2.48; 95% confidence interval, 1.48 to 4.15; P=0.0005; odds ratio, 1.97; 95% confidence interval, 1.58 to 2.46; P<0.0001; and odds ratio, 2.55; 95% confidence interval, 1.98 to 3.27; P<0.0001, respectively).

CONCLUSIONS

We report for the first time a circulating miRNA profile for hypertensive patients and demonstrate a novel link between HCMV infection and essential hypertension. These findings may reveal important insights into the pathogenesis of essential hypertension.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. UNIQUE IDENTIFIER: NCT00420784.