Epstein-Barr Nuclear Antigen Research Articles

Epstein–Barr virus, cytomegalovirus and BK polyomavirus burden in juvenile systemic lupus erythematosus: correlation with clinical and laboratory indices of disease activity

Clinical and laboratory investigations have revealed that Epstein-Barr virus (EBV) is involved in altered immunological response of systemic lupus erythematosus (SLE). Higher seroprevalence rates of anti-EBV antibodies and increased viral load are demonstrated in adult SLE patients. The prevalence of BK polyomavirus (BKV) reactivation is also suggested to be higher in SLE. Herein, we aimed to evaluate the immune response of children with SLE to EBV antigens in addition to EBV and BKV DNA. We also tried to evaluate whether these serological results differ from another connective tissue disease - juvenile systemic sclerosis (jSS) - and healthy individuals. Serum levels of EBV early antigen diffuse (EA-D) IgG, EBV nuclear antigen-1 IgG, EBV viral capsid antigen (VCA), cytomegalovirus (CMV) IgG, EBV DNA, CMV DNA and urinary BKV DNA were evaluated in healthy controls and in patients with a diagnosis of juvenile SLE (jSLE) and jSS. A total of 70 jSLE patients, 14 jSS patients and 44 sex-matched healthy individuals were involved in the study. EBV VCA was positive in 84.2% of jSLE patients, 85.7% of jSS patients and 36.3% of healthy controls. EBV EA-D IgG positivity was significantly higher in jSLE patients compared to jSS patients and healthy controls (20% vs. 7.1% and 0%, p = 0.005). EBV VCA positivity was associated with malar rash and immunological disorder, but there was no statistical significance in other antibody positivity in terms of clinical and haemogram findings and autoantibody positivity. CMV DNA positivity was present in only 2.8% of jSLE patients. None of the jSS patients or the healthy controls had CMV DNA positivity. EBV DNA and BKV DNA were also negative in all three groups. The results of our study assume a relationship between SLE and EBV, but we could not demonstrate an association between CMV and BKV. The negative DNA results in contrast to serological positivity can be interpreted as an altered and impaired immune system and increased viral susceptibility. These results suggest that EBV contributes to disease continuity, even if it does not directly cause development.

Recombinant Epstein-Barr virus glycoprotein 350 as a serological antigen

Epstein-Barr virus (EBV) glycoprotein 350 (gp350) is the most abundant glycoprotein expressed on the EBV envelope, the major target for neutralizing antibodies and also essential for virion attachment to B lymphocytes. Several studies have addressed EBV gp350 as a vaccine candidate, but less commonly as a potential antigen for serological assays. The aim of the current study was to develop a diagnostic tool to quantify EBV gp350-specific IgG in previously EBV-infected individuals. A construct encoding the extracellular domain of EBV gp350 (amino acid (aa) 1–860) was developed for expression in Chinese hamster ovary cells. Serum samples (n = 360) with known IgG serostatus against viral capsid antigen (VCA) and Epstein-Barr nuclear antigen 1 (EBNA1) were divided into three groups based on the differences in their serostatus: VCA + EBNA1+ (n = 120), VCA + EBNA1- (n = 120) and VCA-EBNA1- (n = 120). The samples were analyzed by indirect ELISA using recombinant EBV gp350 aa 1–860 as antigen. A clear majority, 108 of the 120 VCA + EBNA1+ samples, had detectable EBV gp350-specific IgG. Of the 120 VCA + EBNA1- samples, 79 had detectable EBV gp350-specific IgG. Only 2 of the 120 VCA-EBNA1- samples had detectable EBV gp350-specific IgG. The results reported here show that use of the EBV gp350 aa 1–860 ELISA can serve as a sensitive method for EBV-specific IgG detection in serum samples.

Mechanisms of Epstein-Barr virus nuclear antigen 1 favor Tregs accumulation in nasopharyngeal carcinoma.

BackgroundDocumented reports proved that Epstein‐Barr virus (EBV) infection increased infiltration of Tregs in malignancy. However, the mechanism of EBV recruitment Tregs into nasopharyngeal carcinoma (NPC) tissues has not been detailed discussion.MethodsExpression of EBV nuclear antigen 1 (EBNA1) and Foxp3 in NPC tissue samples was detected by immunohistochemistry. EBNA1+ NPC cell lines were used to coculture with PBMC, naïve T cells, Tregs, and monocytes. Percent of Treg was detected by flow cytometry.ResultsEBNA1 protein was overexpressed in NPC tissues, and was associated with a number of infiltrated Tregs. EBNA1+ NPC cells converted naïve T cells into Tregs by up‐regulated TGF‐β1. Enhanced CCL20 production in EBNA1‐expressed tumor cells increased Tregs migration. Polarized‐M2 macrophages by EBNA1 expression cells converted naïve T cells into Tregs.ConclusionsEBNA1 favors accumulation of Tregs in NPC through: (a) upregulated TGF‐β1 converted naïve T cell into Treg; (b) upregulated CCL20 increased Treg migration; and (c) polarized‐M2 macrophage converted naïve T cell into Treg.

Functional interplay of Epstein-Barr virus oncoproteins in a mouse model of B cell lymphomagenesis

Epstein-Barr virus (EBV) is a B cell transforming virus that causes B cell malignancies under conditions of immune suppression. EBV orchestrates B cell transformation through its latent membrane proteins (LMPs) and Epstein-Barr nuclear antigens (EBNAs). We here identify secondary mutations in mouse B cell lymphomas induced by LMP1, to predict and identify key functions of other EBV genes during transformation. We find aberrant activation of early B cell factor 1 (EBF1) to promote transformation of LMP1-expressing B cells by inhibiting their differentiation to plasma cells. EBV EBNA3A phenocopies EBF1 activities in LMP1-expressing B cells, promoting transformation while inhibiting differentiation. In cells expressing LMP1 together with LMP2A, EBNA3A only promotes lymphomagenesis when the EBNA2 target Myc is also overexpressed. Collectively, our data support a model where proproliferative activities of LMP1, LMP2A, and EBNA2 in combination with EBNA3A-mediated inhibition of terminal plasma cell differentiation critically control EBV-mediated B cell lymphomagenesis.

Prolonged siRNA expression in mammalian cells using an Epstein–Barr virus-based plasmid expression system

RNA interference (RNAi) is a powerful tool in gene function analysis and disease treatment, especially diseases that are ‘undruggable’ by classical small molecules. However, the RNAi applications are limited due to some defects, such as short duration and toxic side effects. New strategies are still needed to improve RNAi applications. Previous studies have illustrated that Epstein-Barr virus nuclear antigen 1 (EBNA-1) and the origin of plasmid replication (oriP) are critical factors for EBV latent gene expression, which can keep the replication of the EBV genome as an extrachromosomal element for a relatively long time. Here we report a plasmid expression system on the base of oriP and EBNA-1, which could produce protein as well as short interfering RNAs(siRNAs) for a long time in mammalian cells. siRNA expression mediated by this system causes efficient and specific down-regulation of gene expression. Except for analyzing gene function, this study also provided a new optional and practical way for protein and/or RNAi-based therapies that require enduring effect.

The role of toll-like receptor 9 (TLR9) in Epstein-Barr virus-associated gastric cancer

Abstract Epstein-Barr virus-associated gastric carcinoma (EBVaGC) is the most common malignancy caused by EBV infection. Toll-like receptors (TLRs) as major components of innate immune system are crucial in the development of inflammatory processes and carcinogenesis. The aim of our study was to evaluate tissue and serum level of TLR9 in EBV-positive and EBV-negative gastric cancer patients. The study involved 30 EBV(+) and 30 EBV(-) patients. EBV DNA was detected in fresh frozen tumor tissue. In serum samples TLR9 level, transforming growth factor β (TGFβ), interleukin 10 (IL-10) and antibodies against EBV were detected using ELISA tests. TLR9 level was also measured in homogenate of tumour tissue. TLR9 level was statistically lower in EBV(+) patients both in serum and tissue, with statistically higher level in tissue than in serum. Lower level of TLR9 was accompanied by higher level of Epstein-Barr virus capsid antigen (EBVCA), Epstein-Barr virus nuclear antigen (EBNA) and early antigen (EA). A lower level of TLR9 was detected in patients with poorly differentiated cancer (G3) and greater lymph nodes involvement (N3-N4). Lower level of TLR9 in patients with EA may point to TLR9 role in reactivation of EBV infection.

Epigenetic reprogramming sensitizes immunologically silent EBV+ lymphomas to virus-directed immunotherapy

AbstractDespite advances in T-cell immunotherapy against Epstein-Barr virus (EBV)-infected lymphomas that express the full EBV latency III program, a critical barrier has been that most EBV+ lymphomas express the latency I program, in which the single Epstein-Barr nuclear antigen (EBNA1) is produced. EBNA1 is poorly immunogenic, enabling tumors to evade immune responses. Using a high-throughput screen, we identified decitabine as a potent inducer of immunogenic EBV antigens, including LMP1, EBNA2, and EBNA3C. Induction occurs at low doses and persists after removal of decitabine. Decitabine treatment of latency I EBV+ Burkitt lymphoma (BL) sensitized cells to lysis by EBV-specific cytotoxic T cells (EBV-CTLs). In latency I BL xenografts, decitabine followed by EBV-CTLs results in T-cell homing to tumors and inhibition of tumor growth. Collectively, these results identify key epigenetic factors required for latency restriction and highlight a novel therapeutic approach to sensitize EBV+ lymphomas to immunotherapy.

DNA methylation enzymes and PRC1 restrict B-cell Epstein-Barr virus oncoprotein expression.

To accomplish the remarkable task of lifelong infection, Epstein-Barr virus (EBV) switches between four viral genome latency and lytic programs to navigate the B-cell compartment and evade immune responses. The transforming program, comprised of highly immunogenic EBV nuclear antigen (EBNA) and Latent Membrane Proteins (LMP), is expressed in newly infected B-lymphocytes and in post-transplant lymphomas. Upon memory cell differentiation and in most EBV-associated Burkitt lymphomas (BL), all but one viral antigen are repressed for immunoevasion. To gain insights into epigenetic mechanisms that restrict immunogenic oncoprotein expression, a genome-scale CRISPR/Cas9 screen was performed in EBV+ BL cells. Here we show that the ubiquitin ligase UHRF1 and its DNA methyltransferase partner DNMT1 were critical for restriction of EBNA and LMP expression. All UHRF1 reader and writer domains were necessary for silencing, and DNMT3B was identified as an upstream viral genome CpG methylation initiator. Polycomb repressive complex I exerted a further layer of control over LMP expression, suggesting a second mechanism for latency program switching. UHRF1, DNMT1 and DNMT3B are upregulated in germinal center B-cells, the BL cell of origin, providing a molecular link between B-cell state and EBV latency program. These results suggest rational therapeutic targets to manipulate EBV oncoprotein expression.

Complete Epstein-Barr virus seropositivity in a large cohort of patients with early multiple sclerosis

ObjectiveTo determine the prevalence of antibodies to Epstein-Barr virus (EBV) in a large cohort of patients with early multiple sclerosis (MS).MethodsSerum samples were collected from 901 patients with a clinically...

Latency III gene products of Epstein-Barr Virus (EBV) are associated with Systemic Lupus Erythematosus (SLE) genetic risk loci

Abstract SLE affects millions with increasing diagnostic prevalence. Genetic studies have identified >600 mostly regulatory variant associations. EBV has been nominated as a causal factor for SLE from immunochemistry and epidemiologic studies. EBNA2 concentrates at SLE risk loci (Nat Genet 50:699 2018) suggesting mechanisms. Additional evidence supporting EBV as an SLE origin would advance this hypothesis of etiology. Previous simulation using our RELI algorithm revealed an astonishing association with Epstein-Barr virus nuclear antigen 2 (EBNA2) (OR=5.96, Pc=E-25) (Nat Genet 50:699, 2018). The >100 risk alleles associated at p<5E-8 for SLE were curated and reduced to 83 loci by linkage disequilibrium pruning. We evaluated the available 53 virally encoded and 13,051 human TF ChIP-seq (chromatin immunoprecipitation with DNA sequencing) datasets. In addition to EBNA2 (now OR=3.7, Pc=1.96E-18 after Bonferroni correction), two of the 53 viral TF data sets, EBNA3C and EBNALP, each of which are EBV Latency III gene products, were also strongly associated with the SLE risk loci (OR=6.0, Pc=4.19E-18; and OR=3.3, Pc=5.53E-18). Moreover, among the human TF datasets strongly associated with SLE risk loci (Pc<E-6), those from EBV infected and transformed B cells are highly concentrated (OR≈56, P<E-100) and, in addition, the human TFs that are known to form super-enhancers upon B cell transformation by EBV (e.g., NFκB subunits) also tend to be concentrated at the SLE risk loci (OR>30, p<E-25). Meanwhile, genetic associations for depression, anxiety, and schizophrenia show no such relationships. These new results further the possible validity of the hypothesis that SLE is originally caused by the Latency III expression program of EBV.

Clinical case of acute meningoencephalomyelopolyradiculoneuritis viral ethiology in the practice of an ambulance doctor

This article presents an analysis of a rare clinical case of acute viral mening oencephalomyelopoliradiculoneuritis in a young 22-year-old girl who was transferred from the Infectious Diseases Hospital, with a diagnosis of serous meningitis. However, within a few days, the patient develops structural epilepsy, moderate mixed upper paraparesis, deep mainly flaccid lower paraparesis, neurogenic urination disorder, paresis of the respiratory muscles, respiratory failure, and therefore the patient is transferred to ICU for 1 month in an unstable serious condition. The diagnosis of acute meningoencephalomyelopoliradiculoneuritis of the viral (EBV etiology) was made on the basis of a medical history, physical and instrumental studies, and the virus was determined in laboratory studies (PCR analysis for EBV 9.7 copies / ml, in cerebrospinal fluid IgG antibody to EBV nuclear antigen, IgE for early EA EBV, IgM for capsid antigen VFF EBV), although EBV was not detected in the blood.

Abstract IA10: Epigenetic remodeling of host metabolic pathways by Epstein-Barr virus (EBV) immortalization

Abstract Epstein-Barr virus (EBV) reprograms host metabolism and gene expression during B-cell immortalization through a highly orchestrated process. The regulatory mechanisms coordinating this reprogramming are not fully elucidated but reflect important events in viral oncogenesis. One clue to this coordinate regulation is provided by the viral-encoded tegument protein BNRF1 that functions in viral chromatin assembly during primary infection and shares extensive structural similarity to a purine biosynthetic enzyme FGARAT (also called PFAS). FGARAT shows strong evolutionary conservation from bacteria to human. Orthologues of BRNF1 are found in all gamma herpesviruses, including KSHV ORF75, and share the common function of disarming components of the PML-nuclear body (PML-NB) and its antiviral functions. We have previously shown that the BNRF1 interacts with the histone H3.3 chaperone DAXX and displaces its interaction with ATRX. ATRX is thought to target Daxx-H3.3 to GC-rich repetitive DNA to repress viral and host telomeric transcription. We found that the BNRF1-DAXX complex changes these functions to facilitate viral gene expression during primary infection, enabling the establishment of EBV latency. However, it is not yet known how the viral FGARAT homology is linked to cellular metabolism and purine biosynthesis. Using metabolomics mass spectrometry, we provide new data indicating that the metabolic pathways are among the most significantly perturbed by EBV during B-cell immortalization. Integrating gene expression (RNA-Seq), chromatin accessibility (ATAC-Seq), and EBV transcription factor binding (ChIP-Seq) we identified several cellular metabolic genes, including adenine deaminase (ADA) and arginosuccinate synthase (ASS1), as a direct target of EBV transcriptional regulation during EBV immortalization. We find that EBV nuclear antigen EBNA1 binds directly to the ADA transcriptional regulatory regions and induces epigenetic changes at this locus. Failure to activate ADA compromises B-cell immortalization. The relationship between BNRF1, EBNA1, and nucleotide metabolism during EBV immortalization will be discussed. These findings suggest that EBV captured a highly conserved purine biosynthetic enzyme to coordinate epigenetic reprogramming with nucleotide metabolism during EBV induced B-cell immortalization. Citation Format: Jason Lamontagne, Andreas Wiedmer, Paul M. Lieberman. Epigenetic remodeling of host metabolic pathways by Epstein-Barr virus (EBV) immortalization [abstract]. In: Proceedings of the AACR Special Conference on the Microbiome, Viruses, and Cancer; 2020 Feb 21-24; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2020;80(8 Suppl):Abstract nr IA10.

Biophysical Screens Identify Fragments That Bind to the Viral DNA-Binding Proteins EBNA1 and LANA.

The human gamma-herpesviruses Epstein–Barr virus (EBV) (HHV-4) and Kaposi’s sarcoma-associated herpesvirus (KSHV) (HHV-8) are responsible for a number of diseases, including various types of cancer. Epstein–Barr nuclear antigen 1 (EBNA1) from EBV and latency-associated nuclear antigen (LANA) from KSHV are viral-encoded DNA-binding proteins that are essential for the replication and maintenance of their respective viral genomes during latent, oncogenic infection. As such, EBNA1 and LANA are attractive targets for the development of small-molecule inhibitors. To this end, we performed a biophysical screen of EBNA1 and LANA using a fragment library by saturation transfer difference (STD)–NMR spectroscopy and surface plasmon resonance (SPR). We identified and validated a number of unique fragment hits that bind to EBNA1 or LANA. We also determined the high-resolution crystal structure of one fragment bound to EBNA1. Results from this screening cascade provide new chemical starting points for the further development of potent inhibitors for this class of viral proteins.

The Impact of EBV On the Epigenetics of Gastric Carcinoma

EBV is an important human tumor virus and is closely related to the occurrence of a variety of tumors, involving 10% of gastric cancer. In EBV-associated gastric carcinoma (EBVaGC), EBV expresses restrict viral genes including EBV nuclear antigen 1, EBV encoded small RNAs, Bam HI-A rightward transcripts, latent membrane protein 2A and miRNAs. The role of EBV in gastric carcinogenesis has received increasing attention and is considered to be another pathogenic factor in addition to Helicobacter pylori. A typical characteristic of EBVaGC is the extensive methylation of viral and host genome. Combined with other epigenetic mechanisms, EBV infection acts as an epigenetic driver of EBVaGC oncogenesis. In this review we discuss recent findings of EBV effect on host epigenetic alterations in EBVaGC and its role in oncogenic process.

Clinical diagnostic criteria of efficiency for combined etiopathogenetic therapy in patients with chronic Epstein–Barr virus infection

Treatment of chronic viral infections accompanied by permanent virus persistence in the target epitopes of the oral cavity, skin, urogenital tract is complicated by virtual lack of available drugs exerting combined systemic virulicidal and immunomodulatory effects. Here we demonstrate clinical and immunological efficacy of combined therapy in treatment of Epstein–Barr virus (EBV)-associated chronic infections. The aim of the study was to evaluate the clinical and immunological efficacy of combined etiopathogenetic therapy using the Acegram cosmetic product in patients with EBV-associated chronic infections. Materials and methods. There were enrolled 40 patients monitored before treatment as well as 20 patients followed up after combination therapy (cycle therapy consisted of oral valaciclovir (Valtrex) applied at dose of 500 μg twice a day for 10 days, glucosaminylmuramyldipeptide (Licopid) — 10 mg 2 twice a day for 10 days, topical irrigation for mucous membranes with granulocyte-macrophage colony-stimulating factor active center-derived peptide (Acegram-spray) 3 times a day for 10 days. If necessary, treatment courses were repeated 20 days after the onset. All patients were examined for the presence of EBV genomes in the oral fluid and blood using the qualitative and quantitative polymerase chain reaction (PCR) using the DNA technology test system (Russia) on a DT-Lite device prior treatment and 30, 60 days post-therapy time points. In addition, serum samples were analyzed for level of class G immunoglobulins specific to the EBV nuclear and capsid antigens by using enzyme immunoassay (test systems manufactured by CJSC Vector Best, Russia) as well as immune status (clinical methods, enu flow cytometry evaluation of the phagocytic activity of neutrophils, ELISA method). Results. Use of single or two course combination therapy in subjects with fully eradicated EBV carriage associated with reversed clinical symptoms was accompanied by recovered immune system status (T and B cells, T-helper cells, CD3+ CD25+ cells, phagocytosis parameters). A non-invasive approach proposed for controlling virus elimination in the oral fluid by using polymerase chain reaction method may serve as to objectively monitor therapeutic efficacy.

Monitoring of CMV-specific cell-mediated immunity with a commercial ELISA-based interferon-γ release assay in kidney transplant recipients treated with antithymocyte globulin.

Monitoring for cytomegalovirus (CMV)-specific cell-mediated immunity (CMV-CMI) may be useful for individualizing valganciclovir (VGCV) prophylaxis after kidney transplantation (KT). We performed a commercial ELISA-based interferon (IFN)-γ release assay (QTF-CMV) from posttransplant months 2-5 (362 points) in 120 CMV-seropositive KT recipients that received antithymocyte globulin as induction therapy and VGCV prophylaxis (median of 92days). Forty-seven patients (39.3%) had CMV infection after discontinuation of prophylaxis. The QTF-CMV assay was reactive, nonreactive, and indeterminate in 264 (72.9%), 90 (24.9%), and 8 points (2.2%). The QTF-CMV assay at prophylaxis discontinuation exhibited suboptimal accuracy for predicting protective CMV-CMI (sensitivity: 77.4%; specificity: 34.3%; positive predictive value [PPV]: 64.1%; negative predictive value [NPV]: 50.0%), with no differences in 1-year CMV infection rates between patients with negative (nonreactive or indeterminate) or reactive results (45.8% vs 36.1%; P=.244). Specificity and PPV to predict protective CMV-CMI improved by elevating the IFN-γ cutoff value to 1.13IU/mL (65.7% and 71.4%) and 7.0IU/mL (85.7% and 76.2%), although NPVs decreased. The QTF-CMV assay as per manufacturer's interpretative criteria performed poorly to predict protection from CMV infection following discontinuation of VGCV prophylaxis among ATG-treated CMV-seropositive KT recipients. This performance is slightly improved by modifying the IFN-γ positivity threshold.

The effect of lysosomal-associated membrane protein-1-targeting of Epstein–Barr virus nuclear antigen 1 (EBNA1) on immune response and tumor growth in preclinical studies.

74 Background: Epstein-Barr virus (EBV) is an oncogenic γ-herpes virus that infects > 90% of the global population. EBV is the primary cause of infectious mononucleosis and is associated with several epithelial and lymphoid malignancies, including nasopharyngeal carcinoma, gastric carcinoma, non-Hodgkin’s and Hodgkin’s lymphoma. Of these, nasopharyngeal carcinoma is particularly prevalent in East and Southeast Asia and is highly metastatic. Current treatment strategies for nasopharyngeal carcinoma are limited to radiation and chemotherapy, demonstrating a need for new, targeted therapies. Most nasopharyngeal carcinomas express EBNA1, a DNA-binding protein involved in maintenance of the episomal virus genome that is required for EBV latency and associated transformation. Targeting EBNA1 allows for an immunotherapeutic approach, by exploiting the potential of the immune system to recognize tumor cells through their expression of this viral antigen. Methods: We designed a DNA vaccine encoding EBNA1 using the UNITE (UNiversal Intracellular Targeted Expression) platform. The UNITE platform is based in part on lysosomal targeting technology which results in enhanced antigen presentation and a balanced T cell response. Results: We report that the EBNA1-UNITE vaccine induced IFNγ-producing effector memory (EM) CD4+ T and CD8+ T cells with complete rejection of EBNA1-expressing tumors observed in 50% of mice. Mice rejecting tumors were protected from rechallenge with CT26-EBNA1, demonstrating that antigen-specific memory was induced in these animals. Tumor microenvironment (TME) analysis showed vaccine-induced mobilization of effector cells, including tumor infiltration of IL-12-producing type 1 dendritic cells, iNOS-producing M1 macrophages, activated EM CD4+T, and CD8+TNFα+T cells. Furthermore, increased PD-1+CD8+T cells in the TME suggests that a combination strategy with PD-1/PD-L1 blockade may be beneficial in a therapeutic setting. Conclusions: This pre-clinical data suggests that the EBNA1-UNITE vaccine has the potential to be used as an immunotherapeutic agent against EBV-associated cancers.

Design and molecular docking studies of new inhibitor candidates for EBNA1 DNA binding site: a computational study

ABSTRACTEpstein-Barr virus (EBV), a member of human herpesvirus, causes infectious mononucleosis, Burkitt’s lymphoma, nasopharyngeal carcinoma, gastric carcinoma and Hodgkin lymphomas. Epstein-Barr Nuclear Antigen 1, one of antigens encoded by EBV, comprises 641 amino acid residues. Among the latent infection Epstein-Barr Nuclear Antigen 1 acts in DNA replication, transcription of viral and cellular genes and in immortalisation of B lymphocytes. These special roles of Epstein-Barr Nuclear Antigen 1 make it an important drug target. Therefore, in this study, we create a ligand set of totally 2068 ligands to block binding DNA to Epstein-Barr Nuclear Antigen 1 antigen. After applying Lipinski’s Rule of Five filter to these ligands, 1637 ligands which are suitable to be a drug were run into molecular docking studies. It was seen that designed ligands show more activity to prevent binding DNA to Epstein-Barr Nuclear Antigen 1 antigen rather than ligands selected from the literature which are also studied in vitro and in silico.

Targeting Epstein-Barr virus nuclear antigen 1 (EBNA-1) with Murraya koengii bio-compounds: An in-silico approach.

Epstein-Barr virus (EBV), a B lymphotrophic herpesvirus associated with various forms of tumors, exhibits several latency phases with expressed EBV nuclear antigen 1 (EBNA-1). In the search of novel EBV-inhibiting targets, to curb the menace of EBV-borne lymphotropic transformations, EBNA-1 protein might serve as a best target for novel antiviral natural compounds. This study is thus aimed to explore the inhibitory potential of Muuraya koengii bioactive compounds isomahanine, murrayanol and mahanimbine against the EBNA-1 of EBV. 3D structure of EBNA-1 was retrieved from the PDB data bank with further optimization of both the protein and ligands. In-silico inhibitory potential of the selected M. koengii bio-compounds against EBNA-1 as well as the molecular properties of the derivatives against EBNA-1 were assessed. Murrayanol seems to be a potent inhibitory drug to target EBNA-1 with a promising binding energy of -7.21 with two hydrogen bonds. Drug likeliness parameters recorded murrayanol to be the most promising of the tested compounds, followed by isomahanine. Molecular docking evaluations show that EBNA-1 might be inhibited with M. koengii biocompounds. Keywords: EBV; EBNA; M. koengii; in-silico.

Efficacy of Chemiluminescence Immunoassays on VCA-IgA and EBNA1-IgA Antibodies of Epstein-Barr Virus in Diagnosing Nasopharyngeal Carcinoma.

Background: IgA antibodies against Epstein-Barr virus (EBV) capsid antigen (VCA) and nuclear antigen 1 (EBNA1) have been proposed to facilitate the diagnosis and early detection of nasopharyngeal carcinoma (NPC) in high-incidence regions. However, while new methodologies and new platforms for the detection of VCA-IgA and EBNA1-IgA have become available, proper interassay simultaneous comparisons have not been carried out. The study was to compare the performance of the chemiluminescent immunoassays (CLIA) and enzyme-linked immunosorbent assay (ELISA) for VCA-IgA and EBNA1-IgA antibodies, and to evaluate the levels of EBV antibodies in healthy population from different areas of China.Methods: CLIA and ELISA for VCA-IgA and EBNA1-IgA were performed in NPC and healthy populations from high-incidence areas of NPC in South China (N=555), medium-incidence areas of NPC in Central China (N=318) and low-incidence areas of NPC in North China (N=379), and the results were compared and analyzed.Results: (1) The highest sensitivity in total, early and advanced NPC were 91.5% (CLIA for VCA-IgA), 86.4% (CLIA and ELISA-2 for EBNA1-IgA) and 93.6% (CLIA for VCA-IgA). However, the specificity of EBV-IgA measured by CLIA was relatively lower than ELISA. The top three seromarkers with the largest AUC was CLIA for VCA-IgA (AUC: 0.929, 95% CI: 0.905-0.953), ELISA-2 for EBNA1-IgA (AUC: 0.922, 95% CI: 0.896-0.947) and CLIA for EBNA1-IgA (AUC:0.919, 95% CI: 0.893-0.945), respectively. The positive and negative coincidence rates of the two EBNA1-IgA kits were 69.5% and 91.9%, respectively. However, the coincidence rates of VCA-IgA were relatively low. CLIA kits had good repeatability between different laboratories. (2) The positive rates of EBV-IgA antibodies were relatively high in high-incidence areas of NPC (P < 0.017), while there was no significant difference in the antibody positive rates between medium-incidence areas and low-incidence areas of NPC (P > 0.05).Conclusions: The performance of EBV-IgA antibodies measured by CLIA has good repeatability, higher sensitivity and similar specificity. The higher EBV-IgA positive rate in healthy subjects by CLIA raises concern about its suitability for NPC-risk screening and requires further analysis.