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1.

Background

Epstein-Barr virus (EBV) was the first virus identified to encode microRNAs (miRNAs). Both of viral and human cellular miRNAs are important in EBV infection. However, the dynamic expression profile of miRNAs during primary EBV infection was unknown. This study aimed to investigate the dynamic expression profile of viral and cellular miRNAs in infectious mononucleosis (IM) caused by primary EBV infection.

Methods

The levels of viral and cellular miRNAs were measured in fifteen pediatric IM patients at three different time-points. Fifteen healthy children who were seropositive for EBV were enrolled in the control group. Relative expression levels of miRNAs were detected by quantitative real-time PCR (qPCR) assay.

Results

EBV-miR-BHRF1-1, 1-2-3P, miR-BART13-1, 19-3p, 11-3P, 12–1, and 16–1 in IM patients of early phase were significantly higher than in healthy children. Most cellular miRNAs of B cells, such as hsa-miR-155-5p, ?34a-5p, ?18b-5p, ?181a-5p, and ?142-5p were up-regulated; while most of cellular miRNAs of CD8?+?T cells, such as hsa-miR-223, ?29c-3p, ?181a, ?200a-3p, miR-155-5p, ?146a, and ?142-5p were down-regulated in IM patients. With disease progression, nearly all of EBV-miRNAs decreased, especially miR-BHRF1, but at a slower rate than EBV DNA loads. Most of the cellular miRNAs of B cells, including hsa-miR-134-5p, ?18b-5p, ?34a-5p, and -196a-5p increased with time. However, most of the cellular miRNAs of CD8?+?T cells, including hsa-let-7a-5p, ?142-3p, ?142-5p, and ?155-5p decreased with time. Additionally, hsa-miR-155-5p of B cells and hsa-miR-18b-5p of CD8+ T cells exhibited a positive correlation with miR-BHRF1-2-5P and miR-BART2-5P (0.96?≤?r?≤?0.99, P?<?0.05). Finally, hsa-miR-181a-5p of B cells had positive correlation with miR-BART4-3p, 4-5P, 16–1, and 22 (0.97?≤?r?≤?0.99, P?<?0.05).

Conclusions

Our study is the first to describe the expression profile of viral and cellular miRNAs in IM caused by primary EBV infection. These results might be the basis of investigating the pathogenic mechanism of EBV-related diseases and bring new insights into their diagnosis and treatment.
  相似文献   

2.
3.

Background

Agaricus blazei Murill (AbM) is an edible Brazilian mushroom that has been used in traditional medicine for a range of diseases. It has been shown to have anti-infection and anti-tumor properties in the mouse, which are due to induction of Th1 responses. On the other hand, IgE-mediated allergy is induced by a Th2 response.

Objective

Since according to the Th1/Th2 paradigm an increased Th1 response may promote a reduced Th2 response, the aim was to examine whether AbM had anti-allergy effects.

Methods

A mouse model for allergy was employed, in which the mice were immunized s.c. with the model allergen ovalbumin (OVA). Additionally, the animals were given a mushroom extract, AndoSan?, mainly (82%) containing AbM, but also Hericium erinaceum (15%) and Grifola frondosa (3%), or PBS p.o. either a day before or 19 days after the immunization. The mice were sacrificed on day 26, and anti-OVA IgE (Th2 response) and IgG2a (Th1 response) antibodies were examined in serum and Th1, Th2 and Treg cytokines in spleen cells cultures.

Results

It was found that the AndoSan? extract both when given either before or after OVA immunization reduced the levels of anti-OVA IgE, but not IgG2a, in the mice. There was a tendency to reduced Th2 relative to Th1 cytokine levels in the AndoSan? groups.

Conclusion

This particular AbM extract may both prevent allergy development and be used as a therapeutical substance against established allergy.  相似文献   

4.
5.

Objectives

To investigate the associations of environmental MS risk factors with clinical and MRI measures of progression in high-risk clinically isolated syndromes (CIS) after the first demyelinating event.

Methods

We analyzed 211 CIS patients (age: 28.9±7.8 years) enrolled in the SET study, a multi-center study of high-risk CIS patients. Pre-treatment samples were analyzed for IgG antibodies against cytomegalovirus (anti-CMV), Epstein Barr virus (EBV) early nuclear antigen-1 (EBNA-1), viral capsid antigen (VCA), early antigen-diffuse (EA-D), 25 hydroxy-vitamin D3 and cotinine levels and HLA DRB1*1501 status. The inclusion criteria required evaluation within 4 months of the initial demyelinating event, 2 or more brain MRI lesions and the presence of two or more oligoclonal bands in cerebrospinal fluid. All patients were treated with interferon-beta. Clinical and MRI assessments were obtained at baseline, 6, 12, and 24 months.

Results

The time to first relapse decreased and the number of relapses increased with anti-CMV IgG positivity. Smoking was associated with increased number and volume of contrast-enhancing lesions (CEL) during the 2-year period. The cumulative number of CEL and T2 lesions during the 2-year period was greater for individuals in the highest quartile of anti-EBV VCA IgG antibodies. The percent loss of brain volume was increased for those in the highest quartile of with anti-EBV VCA IgG antibodies.

Conclusions

Relapses in CIS patients were associated with CMV positivity whereas anti-EBV VCA positivity was associated with progression on MRI measures, including accumulation of CEL and T2 lesions and development of brain atrophy.  相似文献   

6.

Background

Objective markers of early airway inflammation in infants are not established but are of great interest in a scientific setting. Exhaled nitric oxide (FeNO) and urinary eosinophilic protein X (uEPX) are a two such interesting markers.

Objective

To investigate the feasibility of measuring FeNO and uEPX in infants and their mothers and to determine if any relations between these two variables and environmental factors can be seen in a small sample size. This was conducted as a pilot study for the ongoing Swedish Environmental Longitudinal Mother and child Asthma and allergy study (SELMA).

Methods

Consecutive infants between two and six months old and their mothers at children's health care centres were invited, and 110 mother-infant pairs participated. FeNO and uEPX were analysed in both mothers and infants. FeNO was analyzed in the mothers online by the use of the handheld Niox Mino device and in the infants offline from exhaled air sampled during tidal breathing. A 33-question multiple-choice questionnaire that dealt with symptoms of allergic disease, heredity, and housing characteristics was used.

Results

FeNO levels were reduced in infants with a history of upper respiratory symptoms during the previous two weeks (p < 0.002). There was a trend towards higher FeNO levels in infants with windowpane condensation in the home (p < 0.05). There was no association between uEPX in the infants and the other studied variables.

Conclusion

The use of uEPX as a marker of early inflammation was not supported. FeNO levels in infants were associated to windowpane condensation. Measuring FeNO by the present method may be an interesting way of evaluating early airway inflammation. In a major population study, however, the method is difficult to use, for practical reasons.  相似文献   

7.

Background

Cellular miRNAs play an important role in the regulation of gene expression in eukaryotes. Recently, miRNAs have also been shown to be able to target and inhibit viral gene expression. Computational predictions revealed earlier that the HIV-1 genome includes regions that may be potentially targeted by human miRNAs. Here we report the functionality of predicted miR-29a target site in the HIV-1 nef gene.

Results

We find that the human miRNAs hsa-miR-29a and 29b are expressed in human peripheral blood mononuclear cells. Expression of a luciferase reporter bearing the nef miR-29a target site was decreased compared to the luciferase construct without the target site. Locked nucleic acid modified anti-miRNAs targeted against hsa-miR-29a and 29b specifically reversed the inhibitory effect mediated by cellular miRNAs on the target site. Ectopic expression of the miRNA results in repression of the target Nef protein and reduction of virus levels.

Conclusion

Our results show that the cellular miRNA hsa-miR29a downregulates the expression of Nef protein and interferes with HIV-1 replication.  相似文献   

8.
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10.
Epstein-Barr virus (EBV) is an oncogenic virus that ubiquitously establishes life-long persistence in humans. To ensure its survival and maintain its B cell transformation function, EBV has developed powerful strategies to evade host immune responses. Emerging evidence has shown that microRNAs (miRNAs) are powerful regulators of the maintenance of cellular homeostasis. In this review, we summarize current progress on how EBV utilizes miRNAs for immune evasion. EBV encodes miRNAs targeting both viral and host genes involved in the immune response. The miRNAs are found in two gene clusters, and recent studies have demonstrated that lack of these clusters increases the CD4+ and CD8+ T cell response of infected cells. These reports strongly indicate that EBV miRNAs are critical for immune evasion. In addition, EBV is able to dysregulate the expression of a variety of host miRNAs, which influence multiple immune-related molecules and signaling pathways. The transport via exosomes of EBV-regulated miRNAs and viral proteins contributes to the construction and modification of the inflammatory tumor microenvironment. During EBV immune evasion, viral proteins, immune cells, chemokines, pro-inflammatory cytokines, and pro-apoptosis molecules are involved. Our increasing knowledge of the role of miRNAs in immune evasion will improve the understanding of EBV persistence and help to develop new treatments for EBV-associated cancers and other diseases.
  相似文献   

11.
12.

Introduction

Breast cancer is the most common malignancy affecting females worldwide but conventional risk factors are able to explain only a small proportion of these cases. A possible viral etiology for breast cancer has been proposed and Epstein-Barr Virus (EBV) is a widely researched candidate virus. The aim of the present study, first one of its kind from India, was to determine if there is a greater association of EBV infection with breast cancer patients as compared to patients with benign breast diseases.

Methods

We looked for expression of Epstein-Barr Virus Nuclear Antigen-1 (EBNA-1) in breast cancer tissue specimens by employing immunohistochemistry (IHC). We also measured levels of anti-EBNA-1 Immunoglobulin (IgG) antibodies in stored sera of these patients using commercial Enzyme linked Immunosorbent Assay (ELISA) kit. Patients with benign breast diseases were used as a comparison group for both immunohistochemical and serological analysis.

Results

58 cases of malignant breast disease and 63 of benign breast disease (controls) were included in the study. Using manufacturer determined cut-off of 3 IU/ml, 50/55 tested (90.9%) cases and 27/33 tested (81.8%) controls were seropositive for anti-EBNA-1 IgG. Mean antibody levels were significantly higher for cases (54.22 IU/ml) as compared to controls (18.68 IU/ml). IHC for EBNA-1 was positive in 28/51 cases (54.9%). No IHC positivity was noted in the tested 30 controls. Our results show that EBNA-1 expression is seen in a significant proportion of breast cancer tissue specimens from rural India and as compared to patients with benign breast diseases these patients also have a higher immunological response against EBNA-1.  相似文献   

13.

Background

Abnormalities in right ventricular function are known to occur in patients with pulmonary arterial hypertension.

Objective

Test the hypothesis that chronic elevation in pulmonary artery systolic pressure delays mechanical activation of the right ventricle, termed dyssynchrony, and is associated with both symptoms and right ventricular dysfunction.

Methods

Fifty-two patients (mean age 46 ± 15 years, 24 patients with chronic pulmonary hypertension) were prospectively evaluated using several echocardiographic parameters to assess right ventricular size and function. In addition, tissue Doppler imaging was also obtained to assess longitudinal strain of the right ventricular wall, interventricular septum, and lateral wall of the left ventricle and examined with regards to right ventricular size and function as well as clinical variables.

Results

In this study, patients with chronic pulmonary hypertension had statistically different right ventricular fractional area change (35 ± 13 percent), right ventricular end-systolic area (21 ± 10 cm2), right ventricular Myocardial Performance Index (0.72 ± 0.34), and Eccentricity Index (1.34 ± 0.37) than individuals without pulmonary hypertension (51 ± 5 percent, 9 ± 2 cm2, 0.27 ± 0.09, and 0.97 ± 0.06, p < 0.005, respectively). Furthermore, peak longitudinal right ventricular wall strain in chronic pulmonary hypertension was also different -20.8 ± 9.0 percent versus -28.0 ± 4.1 percent, p < 0.01). Right ventricular dyssynchrony correlated very well with right ventricular end-systolic area (r = 0.79, p < 0.001) and Eccentricity Index (r = 0.83, p < 0.001). Furthermore, right ventricular dyssynchrony correlates with pulmonary hypertension severity index (p < 0.0001), World Health Organization class (p < 0.0001), and number of hospitalizations (p < 0.0001).

Conclusion

Lower peak longitudinal right ventricular wall strain and significantly delayed time-to-peak strain values, consistent with right ventricular dyssynchrony, were found in a small heterogeneous group of patients with chronic pulmonary hypertension when compared to individuals without pulmonary hypertension. Furthermore, right ventricular dyssynchrony was associated with disease severity and compromised functional class.  相似文献   

14.

Background

Latent reservoirs of HIV-1 provide a major challenge to its cure. There are increasing reports of interplay between HIV-1 replication and host miRNAs. Several host miRNAs, which potentially target the nef-3′LTR region of HIV-1 RNA, including miR-29a, are proposed to promote latency.

Findings

We used two established cellular models of HIV-1 latency – the U1 monocytic and J1.1 CD4+ T cell lines to show an inverse relationship between HIV-1 replication and miR-29a levels, which was mediated by the HIV-1 Nef protein. Using a miR-29a responsive luciferase reporter plasmid, an expression plasmid and an anti-miR29a LNA, we further demonstrate increased miR-29a levels during latency and reduced levels following active HIV replication. Finally, we show that miR-29a levels in the PBMCs and plasma of HIV infected persons also correlate inversely with latency and active viral replication.

Conclusions

The levels of miR-29a correlate inversely with active HIV-1 replication in cell culture models and in HIV infected persons. This links miR-29a to viral latency and suggests another approach to activate and destroy latent HIV-1 reservoirs.
  相似文献   

15.

Background

miRNAs are a class of non-coding RNA molecules that play crucial roles in the regulation of virus-host interactions. The ever-increasing data of known viral miRNAs and human protein interaction network (PIN) has made it possible to study the targeting characteristics of viral miRNAs in the context of these networks.

Results

We performed topological analysis to explore the targeting propensities of herpesvirus miRNAs from the view of human PIN and found that (1) herpesvirus miRNAs significantly target more hubs, moreover, compared with non-hubs (non-bottlenecks), hubs (bottlenecks) are targeted by much more virus miRNAs and virus types. (2) There are significant differences in the degree and betweenness centrality between common and specific targets, specifically we observed a significant positive correlation between virus types targeting these nodes and the proportion of hubs, and (3) K-core and ER analysis determined that common targets are closer to the global PIN center. Compared with random conditions, the giant connected component (GCC) and the density of the sub-network formed by common targets have significantly higher values, indicating the module characteristic of these targets.

Conclusions

Herpesvirus miRNAs preferentially target hubs and bottlenecks. There are significant differences between common and specific targets. Moreover, common targets are more intensely connected and occupy the central part of the network. These results will help unravel the complex mechanism of herpesvirus-host interactions and may provide insight into the development of novel anti-herpesvirus drugs.  相似文献   

16.
17.

Background

It remains unclear whether retroviruses can encode and express an intragenomic microRNA (miRNA). Some have suggested that processing by the Drosha and Dicer enzymes might preclude the viability of a replicating retroviral RNA genome that contains a cis-embedded miRNA. To date, while many studies have shown that lentiviral vectors containing miRNAs can transduce mammalian cells and express the inserted miRNA efficiently, no study has examined the impact on the replication of a lentivirus such as HIV-1 after the deliberate intragenomic insertion of a bona fide miRNA.

Results

We have constructed several HIV-1 molecular clones, each containing a discrete cellular miRNA positioned in Nef. These retroviral genomes express the inserted miRNA and are generally replication competent in T-cells. The inserted intragenomic miRNA was observed to elicit two different consequences for HIV-1 replication. First, the expression of miRNAs with predicted target sequences in the HIV-1 genome was found to reduce viral replication. Second, in one case, where an inserted miRNA was unusually well-processed by Drosha, this processing event inhibited viral replication.

Conclusion

This is the first study to examine in detail the replication competence of HIV-1 genomes that express cis-embedded miRNAs. The results indicate that a replication competent retroviral genome is not precluded from encoding and expressing a viral miRNA.  相似文献   

18.
19.
20.

Background

Epstein-Barr virus (EBV) infection represents a major environmental risk factor for multiple sclerosis (MS), with evidence of selective expansion of Epstein-Barr Nuclear Antigen-1 (EBNA1)-specific CD4+ T cells that cross-recognize MS-associated myelin antigens in MS patients. HLA-DRB1*15-restricted antigen presentation also appears to determine susceptibility given its role as a dominant risk allele. In this study, we have utilised standard and next-generation sequencing techniques to investigate EBNA-1 sequence variation and its relationship to HLA-DR15 binding affinity, as well as examining potential cross-reactive immune targets within the central nervous system proteome.

Methods

Sanger sequencing was performed on DNA isolated from peripheral blood samples from 73 Western Australian MS cases, without requirement for primary culture, with additional FLX 454 Roche sequencing in 23 samples to identify low-frequency variants. Patient-derived viral sequences were used to predict HLA-DRB1*1501 epitopes (NetMHCII, NetMHCIIpan) and candidates were evaluated for cross recognition with human brain proteins.

Results

EBNA-1 sequence variation was limited, with no evidence of multiple viral strains and only low levels of variation identified by FLX technology (8.3% nucleotide positions at a 1% cut-off). In silico epitope mapping revealed two known HLA-DRB1*1501-restricted epitopes (‘AEG’: aa 481–496 and ‘MVF’: aa 562–577), and two putative epitopes between positions 502–543. We identified potential cross-reactive targets involving a number of major myelin antigens including experimentally confirmed HLA-DRB1*15-restricted epitopes as well as novel candidate antigens within myelin and paranodal assembly proteins that may be relevant to MS pathogenesis.

Conclusions

This study demonstrates the feasibility of obtaining autologous EBNA-1 sequences directly from buffy coat samples, and confirms divergence of these sequences from standard laboratory strains. This approach has identified a number of immunogenic regions of EBNA-1 as well as known and novel targets for autoreactive HLA-DRB1*15-restricted T cells within the central nervous system that could arise as a result of cross-reactivity with EBNA-1-specific immune responses.  相似文献   

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