Epstein–Barr virus infection–Related hemophagocytic lymphohistiocytosis

We report a case of 27-year-old female diagnosed with hemophagocytic lymphohistiocytosis (HLH) following a recent Epstein–Barr virus (EBV) infection. A known case of relapsing remitting multiple sclerosis on corticosteroids for last 6 months presented to the critical care unit with fever, maculopapular rash and difficulty in breathing. A rapid and correct diagnosis with the precise treatment led to complete recovery of this patient. The HLH is a rare complication of primary EBV infection.     

Cytometric analysis of T cell phenotype using cytokine profiling for improved manufacturing of an EBV‐specific T cell therapy

Adoptive immunotherapy using Epstein–Barr Virus (EBV)‐specific T cells is a potentially curative treatment for patients with EBV‐related malignancies where other clinical options have proved ineffective. We describe improved good manufacturing practice (GMP)‐compliant culture and analysis processes for conventional lymphoblastoid cell line (LCL)‐driven EBV‐specific T cell manufacture, and describe an improved phenotyping approach for analysing T cell products. We optimized the current LCL‐mediated clinical manufacture of EBV‐specific T cells to establish an improved process using xenoprotein‐free GMP‐compliant reagents throughout, and compared resulting products with our previous banked T cell clinical therapy. We assessed effects of changes to LCL:T cell ratio in T cell expansion, and developed a robust flow cytometric marker panel covering T cell memory, activation, differentiation and intracellular cytokine release to characterize T cells more effectively. These data were analysed using a t‐stochastic neighbour embedding (t‐SNE) algorithm. The optimized GMP‐compliant process resulted in reduced cell processing time and improved retention and expansion of central memory T cells. Multi‐parameter flow cytometry determined the optimal protocol for LCL stimulation and expansion of T cells and demonstrated that cytokine profiling using interleukin (IL)‐2, tumour necrosis factor (TNF)‐α and interferon (IFN)‐γ was able to determine the differentiation status of T cells throughout culture and in the final product. We show that fully GMP‐compliant closed‐process culture of LCL‐mediated EBV‐specific T cells is feasible, and profiling of T cells through cytokine expression gives improved characterization of start material, in‐process culture conditions and final product. Visualization of the complex multi‐parameter flow cytometric data can be simplified using t‐SNE analysis.     

The identification of up‐regulated ebv‐miR‐BHRF1‐2‐5p targeting MALT1 and ebv‐miR‐BHRF1‐3 in the circulation of patients with multiple sclerosis

Epstein–Barr virus (EBV) is a well‐documented aetiological factor for multiple sclerosis (MS). EBV encodes at least 44 microRNAs (miRNAs) that are readily detectable in the circulation of human. Previous studies have demonstrated that EBV‐encoded miRNAs regulate host immune response and may serve as biomarkers for EBV‐associated diseases. However, the roles of EBV miRNAs in MS are still unknown. To fill the gap, we conducted a comprehensive profiling of 44 mature EBV miRNAs in 30 relapsing–remitting MS (RRMS) patients at relapse and 30 matched healthy controls. Expression levels of ebv‐miR‐BHRF1‐2‐5p and ebv‐miR‐BHRF1‐3 were elevated significantly in the circulation and correlated positively with the expanded disability status scale (EDSS) scores of MS patients. Receiver operating characteristic (ROC) analyses confirmed that the expression of these two miRNAs distinguished MS patients clearly from healthy controls. Luciferase assays revealed that ebv‐miR‐BHRF1‐2‐5p may directly target MALT1 (mucosa‐associated lymphoid tissue lymphoma transport protein 1), a key regulator of immune homeostasis. In conclusion, we described the expression of EBV miRNAs in MS and preliminarily validated the potential target genes of significantly altered EBV miRNAs. The findings may pave the way for prospective study about the pathogenesis of MS.     

Serum concentration of immunoglobulin G‐type antibodies against the whole Epstein–Barr nuclear antigen 1 and its aa35–58 or aa398–404 fragments in the sera of patients with systemic lupus erythematosus and multiple sclerosis

Several studies suggest that infection by Epstein–Barr virus (EBV) might be one of the environmental factors which facilitates the development of autoimmune disorders in genetically susceptible individuals. Recent data indicate that high anti‐Epstein–Barr nuclear antigen 1 (EBNA)‐1 immunoglobulin (Ig)G titre is a strong risk factor for multiple sclerosis (MS) in patients both with and without the main genetic predisposing trait, human leucocyte antigen (HLA)‐DRB1*15:01. Because no similar studies have been published in systemic lupus erythematosus (SLE) patients, we determined the HLA‐DRB1*15:01 carrier state and the serum titres against the whole EBNA‐1 and its small fragments aa35–58 and aa398–404 in 301 SLE patients, 135 MS patients and in 345 healthy controls. The carrier state of the HLA‐DRB1*15:01 allele was deduced from genotyping of a tagSNP (rs3135388) by applying a Taqman‐based assay. The serum concentrations of antibodies to EBNA‐1 and its aa35–58 or aa398–404 fragments were determined using a commercial assay (ETI‐EBNA‐G) and home‐made enzyme‐linked immunosorbent assays, respectively. The serum concentration of anti‐EBNA‐1 antibodies was significantly (P < 0·001) higher both in MS and SLE patients than in controls. Similar significant differences were found both in HLA‐DRB1*15:01 carriers and non‐carriers. Furthermore, titres of antibodies against the aa35–58 EBNA‐1 fragment were elevated both in MS and SLE patients. By contrast, the levels of aa398–404 EBNA‐1 antibodies were elevated significantly only in the SLE patients. These findings indicate that high anti‐EBNA‐1 IgG titres are HLA‐DRB1*15:01‐independent risk factors not only for MS, but also for SLE, while high antibody titres against the aa398–404 fragment are characteristic for SLE.     

Comparison of two commercial ELISA systems for evaluating anti‐EBNA1 IgG titers

High IgG titers against the Epstein–Barr virus nuclear antigen, EBNA‐1, have been strongly correlated with the risk of developing multiple sclerosis. ELISAs are used frequently to measure EBNA‐1 titers, however concerns remain regarding the accuracy of results. Ordering absolute results into rank quintiles for analysis may be preferable. Using 120 serum samples, two commercially available ELISAs (produced by DiaSorin and VirionSerion) were compared, both in terms of absolute results and rank quintiles. The positive predictive value of the VirionSerion ELISA was 99.1% when compared to the DiaSorin ELISA, however, the negative predictive value was 64.3%. Sensitivity and specificity were acceptable at 95.5% and 90.0%, respectively. There was poor correlation between absolute results, R² = 0.49; and the kappa coefficient for rank quintiles was low at 0.23. Although sensitivity and specificity appear adequate, the poor negative predictive value and kappa coefficient are of major concern. Care must be taken when selecting assays for experimental use. J. Med. Virol. 85:128–131, 2012. © 2012 Wiley Periodicals, Inc.     

Activation of epitope-specific memory cytotoxic T lymphocyte responses by synthetic peptides

Cytotoxic T lymphocytes (CTL) recognize antigens as short peptides selected for presentation by their ability to bind to MHC class I molecules. Polyclonal Epstein–Barr virus (EBV)-specific memory CTL responses, reactivated from blood lymphocytes of HLA-A11-positive individuals by stimulation with the autologous EBV-transformed lymphoblastoid cell line (LCL), are often dominated by reactivities directed to the peptide epitope IVTDFSVIK (IVT), corresponding to amino acids 416–424 of EBV nuclear antigen-4 (EBNA4). We now report the selective activation of IVT-specific CTL by stimulation of lymphocytes with the corresponding synthetic peptide. A more than 10-fold increase in frequency of CTL clones with this specificity (from 8% to 96%) was obtained when the peptide was presented by HLA-A11-transfected T2 cells (T2/A11). Titration of synthetic peptide in cytotoxic assay demonstrated that clones activated under these conditions are as efficient as clones activated by conventional LCL stimulations. Induction of memory CTL responses required low surface density of MHC : peptide complexes, since reactivation was achieved by stimulation with T2/A11 cells pulsed with concentrations of peptide that are suboptimal for induction of target cell lysis. This protocol of activation revealed the presence of IVT-specific CTL precursors in a donor that failed to mount an IVT-specific response upon stimulation with the autologous B95·8 virus-transformed LCL. The results suggest that stimulation with synthetic peptide epitopes can be efficiently used for induction of memory CTL responses, and may be particularly helpful for the selective expansion of subdominant CTL specificities.     

Cytolytic mechanisms and T-cell receptor Vβ usage by ex vivo generated Epstein–Barr virus-specific cytotoxic T lymphocytes

Ex-vivo-generated Epstein–Barr virus (EBV)-specific cytotoxic T lymphocytes (CTL) have been used for cellular adoptive immunotherapy of EBV-associated lymphomas. Here we investigated the phenotypes, cytolytic mechanisms, polyfunctionality and T-cell receptor (TCR) usage in growing and established CTL, generated by weekly stimulation with an EBV-transformed autologous lymphoblastoid cell line (LCL). Our results showed that phenotypically mature CTL developed within the first 4 weeks of culture, with an increase in CD45RO and CD69, and a decrease in CD45RA, CD62L, CD27 and CD28 expression. Spectratyping analysis of the variable β-chain of the TCR revealed that TCR repertoire remained diverse during the course of culture. Cytotoxicity of CTL was significantly inhibited by concanamycin A (P < 0·0001) and ethylene glycol-bis tetraacetic acid (P < 0·0001), indicating that a calcium and perforin-mediated exocytosis pathway with the release of granzyme B was the principal cytotoxic mechanism. The CTL mainly produced interferon-γ (IFN-γ) or tumour necrosis factor-α (TNF-α) upon restimulation with autologous LCL, although there were some polyfunctional cells producing IFN-γ and TNF-α. Granzyme B, perforin and Fas ligand were detected in CD8⁺ and CD4⁺ cells in all CTL; however, a greater proportion of CD8⁺ than CD4⁺ T cells expressed granzyme B (P < 0·0001) and more granzyme B was detected in CD8⁺ T cells than in CD4⁺ T cells (P = 0·001). This difference was not observed with Fas ligand or perforin expression. Our results provide insight into the basic characteristics of ex-vivo-generated CTL.     

Changes in chemokines and chemokine receptor expression on tonsillar B cells upon Epstein–Barr virus infection

Chemokines and chemokine receptors are likely to play important roles in the pathogenesis of Epstein–Barr virus (EBV) -associated disease. The primary EBV infection occurs in the oropharynx where the virus infects mainly tonsillar B cells. We have previously shown that CXCR4 expression on tonsillar B cells is modulated by EBV. Here, CXCR5 and CCR7 expression, which is important for migration into lymphoid tissue, was followed for 14 days after EBV infection of tonsillar B cells. Early after infection (2 days) there were only minor changes in CXCR5 and CCR7 expression. However, at day 7 the expression of CXCR5, as well as of CCR7, was decreased and by day 14 these molecules were no longer present at the cell surface. Furthermore, EBV infection affects the chemotactic response to CXCL13 and CCL21 (the ligands for CXCR5 and CCR7, respectively) with a reduction of ligand-induced migration at day 2. Using gene expression profiling, we identified an additional set of chemokines and chemokine receptors that were changed upon EBV infection in comparison with non-infected tonsillar B cells. In particular, messenger RNA expression for CCR9 and the complement receptor C5AR1 was increased. Both receptors mediate homing to mucosal tissue. The alterations of the expression of these molecules may lead to retention of EBV-infected tonsillar B cells in the interfollicular region of the tonsil.     

Illuminating vitamin D effects on B cells – the multiple sclerosis perspective

Vitamin D is associated with many immune‐mediated disorders. In multiple sclerosis (MS) a poor vitamin D status is a major environmental factor associated with disease incidence and severity. The inflammation in MS is primarily T‐cell‐mediated, but increasing evidence points to an important role for B cells. This has paved the way for investigating vitamin D effects on B cells. In this review we elaborate on vitamin D interactions with antibody production, T‐cell‐stimulating capacity and regulatory B cells. Although in vitro plasma cell generation and expression of co‐stimulatory molecules are inhibited and the function of regulatory B cells is promoted, this is not supported by in vivo data. We speculate that differences might be explained by the B‐cell–Epstein–Barr virus interaction in MS, the exquisite role of germinal centres in B‐cell biology, and/or in vivo interactions with other hormones and vitamins that interfere with the vitamin D pathways. Further research is warranted to illuminate this tube‐versus‐body paradox.     

Establishment of anti-Epstein–Barr virus (EBV) cellular immunity by adoptive transfer of virus-specific cytotoxic T lymphocytes from an HLA-matched sibling to a patient with severe chronic active EBV infection

We describe an experience of a specific immune transfer treatment in a patient with chronic active EBV infection. The patient had low anti-EBV T cell-mediated cytotoxic activity in his peripheral blood mononuclear cells (PBMC), which may have been the primary cause of the disease. An EBV-specific cytotoxic T lymphocyte (CTL) line was established from PBMC obtained from the patient’s sister whose human leucocyte antigens (HLA) are identical to patient's. The patient received three courses of intravenously administered CTL at 3-week intervals. The number of the cells was increased with each course of treatment. After infusion of the T cell line, anti-EBV CTL activity was detected in the patient's PBMC. CTL activity increased markedly after the second course of immune transfer therapy. The amount of EBV DNA in the patient's plasma showed transient but repeated decreases. Serum levels of tumour necrosis factor-alpha (TNF-α), which had elevated before treatment, began to decrease after initiation of treatment. No adverse effects were directly associated with CTL infusions. Despite having previously received a pneumococcal vaccine and prophylactic antibodies, the patient died of infection caused by Streptococcus pneumoniae bacteraemia 27 days after the third infusion. Although the long-term efficacy and safety of this therapy remains to be established, our findings suggest that adoptive transfer of CTL specific for EBV obtained from an HLA-matched donor might be a promising treatment for patients with chronic active EBV infection.     

Generation of human neutralizing monoclonal antibodies against the 2009 pandemic H1N1 virus from peripheral blood memory B lymphocytes

The 2009 H1N1 influenza pandemic demonstrated the significance of a global health threat to human beings. Although pandemic H1N1 vaccines have been rapidly developed, passive serotherapy may offer superior immediate protection against infections in children, the elderly and immune-compromised patients during an influenza pandemic. Here, we applied a novel strategy based on Epstein–Barr virus (EBV)-immortalized peripheral blood memory B cells to screen high viral neutralizing monoclonal antibodies (MAbs) from individuals vaccinated with the 2009 pandemic H1N1 vaccine PANFLU.1. Through a massive screen of 13 090 immortalized memory B-cell clones from three selected vaccinees, seven MAbs were identified with both high viral neutralizing capacities and hemagglutination inhibition (HAI) activities against the 2009 pandemic H1N1 viruses. These MAbs may have important clinical implications for passive serotherapy treatments of infected patients with severe respiratory syndrome, especially children, the elderly and immunodeficient individuals. Our successful strategy for generating high-affinity MAbs from EBV-immortalized peripheral blood memory B cells may also be applicable to other infectious or autoimmune diseases.     

Cytomegalovirus and Epstein–Barr virus coinfection in three toddlers with prolonged illnesses

Cytomegalovirus (CMV) and Epstein–Barr virus (EBV) usually cause primary and latent infections during childhood; thus, coinfection with these viruses occurs occasionally in children. However, its clinical impact has not been established, and may be underestimated. Three cases of coinfection involving these two viruses in toddlers are described: a 14‐month‐old male with infectious mononucleosis, an 18‐month‐old female with hemophagocytic lymphohistiocytosis, and a 13‐month‐old female with acute hepatitis. All three patients had prolonged illnesses. Serial serological testing and quantitation of viral DNA for CMV and EBV using peripheral blood from the patients suggested primary infections with both viruses. In all three cases, the viral load of EBV and CMV in the early stage of disease exceeded 6.4 × 10³ and 8.8 × 10² copies/ml of whole blood, respectively, suggesting that the viruses were associated with the clinical condition. Recognizing that coinfection with these viruses may modulate the clinical course of disease is important. J. Med. Virol. 81:1399–1402, 2009. © 2009 Wiley‐Liss, Inc.     

Serum sCD23 Level in Patients with AIDS-Related Non-Hodgkin''s Lymphoma Is Associated with Absence of Epstein–Barr Virus in Tumor Tissue

The cytokine soluble CD23 (sCD23) acts as a B cell growth factor and is associated with Epstein–Barr virus (EBV) infection. To elucidate the role sCD23 might play in the pathogenesis of AIDS-related non-Hodgkin's lymphoma (AIDS NHL), 101 AIDS NHL patients from the Multicenter AIDS Cohort Study were studied. Serum sCD23 within 18 months prior to lymphoma diagnosis was measured for all patients and EBV in tumor tissue was ascertained for 49 patients. Tumor morphology and primary site were verified from pathology reports and tumor specimens. Bivariate tests and multivariate regression were employed to determine whether serum sCD23 correlated with tumor EBV, morphology, and primary site. Higher levels of serum sCD23 were associated with the absence of tumor EBV and with small noncleaved cell morphology. Thus, the serum sCD23 level does not appear to be mediated by EBV in these patients, but could be related to a pathogenetic mechanism of small noncleaved cell lymphoma.     

The ATM tumour suppressor gene is down‐regulated in EBV‐associated nasopharyngeal carcinoma

A micro‐array analysis using biopsies from patients with EBV‐positive undifferentiated nasopharyngeal carcinoma (NPC) and from cancer‐free controls revealed down‐regulation of tumour suppressor genes (TSG) not previously associated with this disease; one such gene was the ataxia telangiectasia mutated (ATM) gene. Q‐PCR confirmed down‐regulation of ATM mRNA and ATM protein expression in tumour cells was weak or absent in almost all cases. In NPC cell lines, however, ATM was down‐regulated only in the EBV‐positive line, C666.1, and in none of five EBV‐negative lines. In vitro infection of EBV‐negative NPC cell lines with a recombinant EBV was followed by the down‐regulation of ATM mRNA and protein, and only EBV‐positive cells showed a defective DNA damage response following γ‐irradiation. Our data suggest that loss of ATM function could be an important step in the pathogenesis of NPC, and may have implications for the treatment of this disease. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Upregulation of LMP1 Expression by Histone Deacetylase Inhibitors in an EBV Carrying NPC Cell Line

OBJECTIVES: In about 60% of Epstein-Barr virus (EBV) carrying nasopharyngeal carcinomas (NPC) LMP1 expressing cells can be detected. The frequency of LMP1 positive cells and the expression level varies from cell to cell in the different tumors. Cell lines derived from EBV positive NPCs loose the virus during in vitro culture. The in vitro infected NPC cell line TWO3-EBV used in our study carries the neomycin-resistance gene containing EBV and expresses low level of LMP1. With this cell line it was thus possible to study the regulation of LMP1 expression by modification of chromatin acetylation state. STUDY DESIGN: The TWO-EBV cell line was treated with n -butyrate (NB) or trichostatin A (TSA). RESULTS: Shown by immunoblotting, the LMP1 level was elevated in the treated samples. Already 2 h after TSA exposure LMP1 expression was higher and it increased up to 24 h. Immunofluorescence staining showed that nearly all cells were LMP1 positive. Neither EBNA2 nor BZLF1 were induced. Tested first 2 h after the treatment, acetylated histone H3 and H4 were already detectable, and their level increased up to 8 h. Chromatin immunoprecipitation (ChIP) verified that the LMP1-promoter (LMP1p) (ED-L1) was acetylated after TSA treatment. CONCLUSION: EBV carrying epithelial cells do not express EBNA-2. We showed that LMP1 expression was upregulated by histone deacetylase inhibitors in an in vitro infected, EBV carrier NPC cell line.