Pattern Of Epstein-Barr Virus Gene Expression Research Articles

A proteome-wide analysis unveils a core Epstein-Barr virus antibody signature of classic Hodgkin lymphoma across ethnically diverse populations.

Epstein-Barr virus (EBV) is an oncogenic virus associated with various malignancies, including classical Hodgkin lymphoma (cHL). Despite its known association, the specific role of humoral immune response to EBV remains poorly characterized in cHL. To address this, we conducted a study using a custom protein microarray to measure the antibody responses in cHL patients and matched healthy controls recruited from an East-Asian hospital-based case-control study. We identified 16 IgG antibodies significantly elevated in EBV-positive cHL compared with controls, defining an "East-Asian antibody signature of EBV-positive cHL." We evaluated responses against these 16 antibodies in a distinct European population, leveraging data from our previous European cHL case-control study from the UK, Denmark, and Sweden. A subset of antibodies (14/16, 87.5%) from the "East-Asian antibody signature of EBV-positive cHL" exhibited significant associations with cHL in the European population. Conversely, we assessed the "European antibody signature of EBV-positive cHL" identified in our prior study which consisted of 18 EBV antibodies (2 IgA, 16 IgG), in the East-Asian population. A subset of these antibodies (15/18, 83.3%) maintained significant associations with cHL in the East-Asian population. This cross-comparison of antibody signatures underscores the robust generalizability of EBV antibodies across populations. Five anti-EBV IgG antibodies (LMP-1, TK, BALF2, BDLF3, and BBLF1), found in both population-specific antibody signatures, represent a "core signature of EBV-positive cHL." Our findings suggest that the antibody responses targeting these core EBV proteins reflect a specific EBV gene expression pattern, serving as potential biomarkers for EBV-positive cHL independent of population-specific factors.

Comprehensive Profiling of EBV Gene Expression and Promoter Methylation Reveals Latency II Viral Infection and Sporadic Abortive Lytic Activation in Peripheral T-Cell Lymphomas.

Epstein-Barr virus (EBV) latency patterns are well defined in EBV-associated epithelial, NK/T-cell, and B-cell malignancies, with links between latency stage and tumorigenesis deciphered in various studies. In vitro studies suggest that the oncogenic activity of EBV in T-cells might be somewhat different from that in EBV-tropic B lymphoid cells, prompting us to study this much less investigated viral gene expression pattern and its regulation in nine EBV+ peripheral T-cell lymphoma (PTCL) biopsies. Using frozen specimens, RT-PCR showed 6/7 cases with a latency II pattern of EBV gene expression. Analyses of EBNA1 promoter usage and CpG methylation status in these six cases showed that only Qp was used, while Cp, Wp, and Fp were all silent. However, the remaining case showed an exceptionally unique latency III type with lytic activation, as evidenced by EBV lytic clonality and confirmed by the full usage of Cp and Qp as well as weakly lytic Fp and Wp, fully unmethylated Cp and marginally unmethylated Wp. Further immunostaining of the eight cases revealed a few focally clustered LMP1+ cells in 7/8 cases, with rare isolated LMP1+ cells detected in another case. Double immunostaining confirmed that the LMP1+ cells were of the T-cell phenotype (CD3+). In 6/8 cases, sporadically scattered Zta+ cells were detected. Double staining of EBER-ISH with T-cell (CD45RO/UCHL1) or B-cell (CD20) markers confirmed that the vast majority of EBER+ cells were of the T-cell phenotype. Predominant type-A EBV variant and LMP1 30-bp deletion variant were present, with both F and f variants detected. In summary, the EBV gene expression pattern in PTCL was found to be mainly of latency II (BART+EBNA1(Qp)+LMP1+LMP2A+BZLF1+), similar to that previously reported in EBV-infected nasopharyngeal epithelial, NK/T-cell, and Hodgkin malignancies; however, fully lytic infection could also be detected in occasional cases. Rare cells with sporadic immediate-early gene expression were commonly detected in PTCL. These findings have implications for the future development of EBV-targeting therapeutics for this cancer.

Genomic Analysis of Nasopharyngeal Carcinoma Reveals TME-Based Subtypes.

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV) associated cancer characterized by a poor prognosis and a high level of lymphocyte infiltrate. Genetic hallmarks of NPC are not completely known but include deletion of the p16 (CDKN2A) locus and mutations in NF-κB pathway components, with a relatively low total mutational load. To better understand the genetic landscape, an integrated genomic analysis was performed using a large clinical cohort of treatment-naïve NPC tumor specimens. This genomic analysis was generally concordant with previous studies; however, three subtypes of NPC were identified by differences in immune cell gene expression, prognosis, tumor cell morphology, and genetic characteristics. A gene expression signature of proliferation was poorly prognostic and associated with either higher mutation load or specific EBV gene expression patterns in a subtype-specific manner. Finally, higher levels of stromal tumor-infiltrating lymphocytes associated with good prognosis and lower expression of a WNT and TGFβ pathway activation signature.Implications: This study represents the first integrated analysis of mutation, copy number, and gene expression data in NPC and suggests how tumor genetics and EBV infection influence the tumor microenvironment in this disease. These insights should be considered for guiding immunotherapy treatment strategies in this disease. Mol Cancer Res; 15(12); 1722-32. ©2017 AACR.

Up-Regulation of Lamin A/C Expression in Epstein-Barr Virus Immortalized B Cells and Burkitt Lymphoma Cell Lines of Activated B Cell Phenotype

Lamin A, B and C, the nuclear intermediate-filament proteins, play a role in epigenetic regulation. Lamin B could be detected in all nucleated cells studied, whereas the lamin A and lamin C isoforms (lamin A/C) encoded by the LMNA gene are co-expressed in most somatic cell types except mature B lymphocytes. Since Epstein-Barr virus (EBV), a human gammaherpesvirus, is associated with tumorigenic processes and is known to alter the epigenotype of its host cells, we studied the expression of the LMNA gene and its epigenetic marks in EBV-carrying human lymphoid cell lines. We observed a high lamin A/C mRNA expression in EBV-immortalized B lymphoblastoid cell lines (LCLs) and in a subset of Burkitt lymphoma (BL) lines characterized by an activated B cell phenotype and a unique latent EBV gene expression pattern (latency III). In these cells the first exon of LMNA was hypomethylated and associated with activating histone marks. In contrast, we observed a low level of lamin A/C mRNA expression in EBV negative BL lines and BL lines with a restricted expression of latent EBV products (latency I). Low LMNA promoter activity was associated with hypermethylation of the LMNA first exon. These data suggest a role for EBV latency products in switching on or upregulating the LMNA promoter (LMNAp) in EBV-infected activated B cells in vitro. Lamin A/C may contribute to the establishment of the activated B cell phenotype. Our data also imply a role of LMNA first exon methylation in the silencing of LMNAp.

Comprehensive profiling of EBV gene expression in nasopharyngeal carcinoma through paired-end transcriptome sequencing.

The latent expression pattern of Epstein-Barr Virus (EBV) genes in nasopharyngeal carcinoma (NPC) has been extensively investigated, and the expression of several lytic genes in NPC has been reported. However, comprehensive information through EBV transcriptome analysis in NPC is limited. We performed paired-end RNA-seq to systematically and comprehensively characterize the expression of EBV genes in NPC tissue and C666-1 NPC cell line, which consistently carries EBV. In addition to the transcripts restricted to type II latency infection, the type III latency EBNA3s genes and a substantial number of lytic genes, such as BZLF1, BRLF1, and BMRF1, were detected through RNA-seq and were further verified in C666-1 cells and NPC tissue through realtime PCR.We also performed clustering analysis to classify NPC patient groups in terms of EBV gene expression, which presented two subtypes of NPC samples. Results revealed interesting patterns of EBV gene expression in NPC patients. This clustering was correlated with many signaling pathways, such as those related to heterotrimeric G-protein signaling, inflammation mediated by chemokine and cytokine signaling, ribosomes, protein metabolism, influenza infection, and ECM-receptor interaction. Our combined findings suggested that the expression of EBV genes in NPC is restricted not only to type II latency genes but also to type III latency and lytic genes. This study provided further insights into the potential role of EBV in the development of NPC.

722. Overcoming EBV Tumor Specific T-Cell Anergy in Rapidly-Generated EBVST-Cells for Adoptive Transfer Therapy

Up to 30% of Hodgkin and non-Hodgkin lymphomas carry the Epstein-Barr virus (EBV) genome and express the viral latency proteins EBNA1, LMP1, LMP2 and BARF1; a type 2 latency pattern of EBV gene expression. We previously reported that EBV-specific T-cells (EBVSTs) directed to LMP1 and LMP2 expanded from the blood of lymphoma patients produced complete tumor responses in over 50% of patients. To shorten and simplify the EBVST production time, we removed viral-vector components from our manufacturing process, replacing these components with dendritic cells pulsed with peptide libraries (pepmixes) spanning type 2 latency antigens. Responder T-cells are then expanded by restimulation with pepmix-pulsed, autologous, activated T-cells and HLA-negative K562 costimulatory cells in the presence of IL-4 and IL-7. Despite enhanced antigen specificity from EBVSTs generated from healthy donors, we were unable to consistently generate patient-derived EBVSTs with significant activity against the Type 2 antigens. We hypothesized that patient T-cells were anergized by their immunosuppressive tumors. IL-15 has been shown to rescue tolerant or anergized CD8+ T-cells and we found that substitution of IL-15 (5ng/mL) for IL-4 (in combination with IL-7 (10ng/mL)) improved CD4+ and CD8+ T-cells’ specificity for the EBV Type 2 latency antigens by up to 10-fold. By increasing the concentration of IL-15, we achieved significantly higher fold expansion (3 fold mean increase in absolute EBVST number) and further enhanced specificity for type 2 latency EBV antigens (high vs. low IL-15 concentration: EBNA1: 216±273 vs. 29±48, LMP1: 145±253 vs. 44±63, LMP2: 636±548 vs. 106±74 and BARF1: 80±100 vs. 29±22; SFC/105 cells; n=5). There was no increase in the absolute numbers of NK-cells despite high doses of IL-15. Enhanced antigen-specificity correlated with increased cytotoxic effect, with an increase in mean % specific lysis of EBV pepmix-pulsed autologous activated T-cell targets from 5 to 66% at a 20:1 E:T ratio in the low vs. high dose IL-15 conditions (n=5). We have infused EBVSTs manufactured using all three conditions into 17 patients with multiply-relapsed, EBV-positive lymphoma as adjuvant therapy after stem cell transplantation or chemotherapy in 8 patients and as treatment for disease in 9 patients. Of patients in remission at the time of infusion, two with IL-4/7-grown EBVSTs and 6 with IL-15/7 grown EBVSTs remain in remission. Of patients with disease at the time of infusion, one receiving IL-4/7-grown EBVSTs had stable disease and 3 had progressive disease, while of 5 patients with IL-15/7-grown EBVSTs, one had stable disease, one had a partial response, one had a complete response and two are too early to assess. We will continue to modify our manufacturing process in an attempt to further increase the specificity and function of EBVSTs from patients with relapsed or refractory lymphoma.

Genome-wide DNA methylation as an epigenetic consequence of Epstein-Barr virus infection of immortalized keratinocytes.

The oral cavity is a persistent reservoir for Epstein-Barr virus (EBV) with lifelong infection of resident epithelial and B cells. Infection of these cell types results in distinct EBV gene expression patterns regulated by epigenetic modifications involving DNA methylation and chromatin structure. Regulation of EBV gene expression relies on viral manipulation of the host epigenetic machinery that may result in long-lasting host epigenetic reprogramming. To identify epigenetic events following EBV infection, a transient infection model was established to map epigenetic changes in telomerase-immortalized oral keratinocytes. EBV-infected oral keratinocytes exhibited a predominantly latent viral gene expression program with some lytic or abortive replication. Calcium and methylcellulose-induced differentiation was delayed in EBV-positive clones and in clones that lost EBV compared to uninfected controls, indicating a functional consequence of EBV epigenetic modifications. Analysis of global cellular DNA methylation identified over 13,000 differentially methylated CpG residues in cells exposed to EBV compared to uninfected controls, with CpG island hypermethylation observed at several cellular genes. Although the vast majority of the DNA methylation changes were silent, 65 cellular genes that acquired CpG methylation showed altered transcript levels. Genes with increased transcript levels frequently acquired DNA methylation within the gene body while those with decreased transcript levels acquired DNA methylation near the transcription start site. Treatment with the DNA methyltransferase inhibitor, decitabine, restored expression of some hypermethylated genes in EBV-infected and EBV-negative transiently infected clones. Overall, these observations suggested that EBV infection of keratinocytes leaves a lasting epigenetic imprint that can enhance the tumorigenic phenotype of infected cells. Here, we show that EBV infection of oral keratinocytes led to CpG island hypermethylation as an epigenetic scar of prior EBV infection that was retained after loss of the virus. Such EBV-induced epigenetic modification recapitulated the hypermethylated CpG island methylator phenotype (CIMP) observed in EBV-associated carcinomas. These epigenetic alterations not only impacted gene expression but also resulted in delayed calcium and methylcellulose-induced keratinocyte differentiation. Importantly, these epigenetic changes occurred in cells that were not as genetically unstable as carcinoma cells, indicating that EBV infection induced an epigenetic mutator phenotype. The impact of this work is that we have provided a mechanistic framework for how a tumor virus using the epigenetic machinery can act in a "hit-and-run" fashion, with retention of epigenetic alterations after loss of the virus. Unlike genetic alterations, these virally induced epigenetic changes can be reversed pharmacologically, providing therapeutic interventions to EBV-associated malignancies.

EBV Load in Whole Blood Correlates With LMP2 Gene Expression After Pediatric Heart Transplantation or Allogeneic Hematopoietic Stem Cell Transplantation

Epstein-Barr virus (EBV) is associated with posttransplant lymphoproliferative disease (PTLD), and EBV load measurement is an important tool to monitor transplant patients. Although EBV DNA quantification has high sensitivity to identify patients at risk for PTLD, it lacks specificity. We examined whether EBV gene expression in peripheral B cells can increase specificity or correlates with EBV load. Altogether, 220 blood samples were collected from pediatric patients after heart transplantation (HTx, n=57), renal transplantation (n=1), or hematopoietic stem cell transplantation (n=21). In each blood sample, EBV load was quantified in whole blood, plasma, and B cells using qPCR. Additionally EBV gene expression (EBNA2, LMP1, LMP2, and BZLF1) in B cells was analyzed using relative quantitative RT-qPCR. Positive expression of at least one gene was detected in 112 (51%) of 220 samples. Patients with PTLD or chronic high viral loads after solid organ transplantation exhibited no homogeneous EBV gene expression pattern. Expression of LMP2, LMP1, or EBNA2 was only observed when EBV load exceeded 1000 copies/mL. A high correlation between the level of LMP2 expression and EBV load in B cells or whole blood was observed (ρ=0.72 or ρ=0.6, HTx population). The analysis of EBV gene expression in peripheral B cells does not provide additional information about patients' risk of developing PTLD. As EBV load in whole blood correlates well with LMP2 gene expression in EBV-infected B cells, EBV DNA quantification in whole blood alone seems to be a sufficient tool to monitor these patients.

Epstein–Barr virus gene expression and latent membrane protein 1 gene polymorphism in pediatric liver transplant recipients

Immunosuppressed pediatric transplant recipients are at risk of developing Epstein-Barr virus (EBV)-associated complications (such as post-transplant lymphoproliferative disorders). Monitoring of the EBV DNA level in blood alone has a low predictive value for the post-transplant course of EBV infection and its complications. Therefore, additional prognostic markers are widely sought. The study aim was to analyze EBV gene expression patterns and LMP1 polymorphism in relation to EBV DNA levels in pediatric liver transplant recipients. EBV load measurement, LMP1 variant, and gene expression analysis were performed in collected prospectively multiple blood samples from 30 patients. Several distinct patterns of EBV gene expression were identified: latency 2 (71%), latency 3 (13%), latency 0 (11%), and lytic infection (5%). In most children's multiple blood samples, both EBV gene expression patterns and expression levels of individual EBV genes varied significantly over time. EBV gene expression patterns were not associated with the EBV load. However, the viral load correlated with the LMP1 and LMP2 expression (r = 0.34; P = 0.006, and r = 0.45; P = 0.001, respectively). Two variants of the LMP1 gene were detected, and they were consistent over time in individual patients. A wild type of LMP1 was associated with higher EBV-DNA loads (P = 0.03). This indicates that EBV infection in immunosuppressed patients is a very dynamic process, but changes in the state of EBV infection do not influence significantly the viral load. The latter, however, can be associated with the activity of LMP1 and LMP2 genes, as well as polymorphism of LMP1.

TNFAIP3 (A20) Genetic Alterations In EBV Associated AIDS Related Lymphomas

AbstractAbstract 802 Introduction:AIDS related lymphomas (ARL) are a heterogeneous group of lymphoproliferative disorders that are frequently associated with Epstein Barr virus (EBV) infection. EBV expresses latent viral oncoproteins that constitutively activate the transcription factor NF-κB, a potent inducer of genes involved in B cell survival and proliferation (Keller SA et al, Blood 2006). Lymphomas that are not associated with EBV can also display increased NF-κB activity and recent reports have described mutations in regulators of NF-κB in subsets of B cell lymphomas. One of the frequently mutated regulatory genes is TNFAIP3, which encodes A20, an ubiquitin modifying enzyme involved in the termination of NF-κB signaling. Mutations resulting in the inactivation of A20 have been found in a significant proportion of marginal zone lymphoma (Novak U et al, Blood 2009), classical Hodgkin lymphoma, primary mediastinal B cell lymphoma (Schmitz R et al, J Exp Med 2009), and diffuse large B cell lymphoma (Compagno M et al, Nature 2009). In ARL the incidence of alterations in A20 and the relationship with EBV infection has not been described. Materials and Methods:We evaluated archival formalin fixed paraffin embedded tissue samples of ARL for genetic alterations in A20. Tissue was collected through an international collaboration between Weill Cornell Medical College in New York, USA and Siena University in Siena, Italy. A tissue microarray with 46 cases of ARL was prepared and characterization of lymphoma subtype and EBV viral status were determined by immunohistochemistry and in situ hybridization for Epstein-Barr encoded RNA. Fluorescent in situ hybridization (FISH) was used to evaluate for genomic deletions in A20, and translocations of cMYC, BCL-2 and BCL-6. Direct sequencing of the coding region and splice sites of A20 was performed to evaluate for additional genetic alterations. Immunohistochemistry was used to evaluate for the presence of A20 protein. Results:Fluorescent in situ hybridization revealed A20 monoallelic or biallelic deletion in 6 of 25 cases (24%). A20 point mutations were found in 3 of 23 cases (13%). Nonsense mutations coding for a premature stop codon in exon 2 were seen in 2 cases. The third case was found to have a missense mutation in exon 7 resulting in an amino acid change. Two of the 3 cases with an A20 point mutation had A20 deletion in the complementary allele indicating biallelic alteration of the A20 gene. Immunohistochemistry for A20 was performed and is reported for the first time in this abstract. Absence of A20 protein was demonstrated in 4 of 33 samples (12%). Included among the cases negative for A20 on immunohistochemistry is the single case with biallelic A20 deletion demonstrated by FISH. In total 10 of 39 (26%) cases with adequate sample for evaluation were determined to have inactivation of A20 by FISH, sequencing, immunohistochemistry, or a combination. A20 inactivation was seen among all histologic subtypes of ARL including Burkitt lymphoma (n=2), diffuse large B cell lymphoma of the germinal center B cell (n=2) and non-germinal center B cell (n=2), plasmablastic lymphoma (n=3) and B cell lymphoma, unclassifiable, intermediate between BL and diffuse large B cell lymphoma (n=1). Interestingly, the incidence of EBV infection was higher in cases with A20 inactivation than in those with intact A20. EBV was present in 6/10 cases with A20 alteration (60%) vs. 8/29 cases with intact A20 (28%). The EBV latent viral protein LMP-1, which activates NF-κB, was not expressed in cases with A20 alteration. Conclusions:This is the first report to demonstrate A20 inactivation in EBV-associated lymphoma. A20 molecular analysis has been previously reported in Hodgkin Lymphoma (HL) where A20 inactivation and EBV infection were found to be almost mutually exclusive (Schmitz R et al, J Exp Med 2009). The EBV gene expression pattern differs in HL and ARL. In HL EBV expresses the viral oncoprotein LMP-1, which leads to constitutive activation of NF-κB. In ARL viral gene expression is more heterogeneous and in this cohort of ARL, LMP-1 was not expressed in any of the cases with EBV infection and A20 loss. Our data indicate that A20 may represent a tumor suppressor gene in a significant subset of ARL and that A20 inactivation may be associated with positive EBV status. In EBV related lymphoma inactivation of A20 may be an alternative mechanism of NF-κB upregulation in the absence of LMP-1. Disclosures:No relevant conflicts of interest to declare.

Epstein-Barr virus (EBV)-associated miRNAs are important for the maintenance of EBV transformed B cells

The human oncogenic gamma-herpesvirus, Epstein-Barr virus (EBV), infects approximately 95% of the adult human population and causes B-cell lymphomas in immune-compromised individuals, such as AIDS patients. EBV transforms primary human B cells into indefinitely proliferating lymphoblastoid cell lines (LCLs) in vitro, which represents an important model system for the transformation of B cells by EBV. EBV encodes 25 viral miRNA, but their role in virus replication and pathogenesis is unclear. Three of these miRNAs, miR-BHRF1-1, miR-BHRF1-2, and miR-BHRF1-3, are expressed during the latency III stage of EBV, the EBV gene expression pattern observed in AIDS-associated B cell lymphomas and LCLs. We have performed functional studies examining the roles of the three BHRF1 miRNAs during the transformation of primary B cells by EBV in vitro as well as in the maintenance of the transformed state in established LCL cultures. Our preliminary data suggest that at least one EBV miRNA is necessary for LCL outgrowth. EBV is also known to up-regulate a number of cellular microRNAs, including miR-155, and our preliminary data also suggest a role of miR-155 in the maintenance of LCLs. We are currently examining the mechanisms by which EBV and cellular microRNAs contribute to the growth and maintenance of LCLs. Together, our data point to a role for EBV-encoded and EBV-induced miRNAs in EBV-induced cell transformation.

High-Dose Methotrexate and Azidothymidine in Combination with Alternating DA-EPOCH Is An Effective Regimen for the Treatment of EBV-Related Plasmablastic Lymphoma.

Abstract 4753 IntroductionPlasmablastic lymphoma (PBL) is an aggressive and generally fatal, rare type of B-cell non-Hodgkin's lymphoma (NHL) with predilection to sino-oral mucosa. PBL is usually associated with human immunodeficiency virus (HIV) and displays an unusual phenotype lacking the expression of B-cell surface antigens. PBLs are infected by Epstein Barr virus (EBV) in approximately 80% of cases and exhibit a restricted pattern of EBV gene expression as they do not typically express latent membrane proteins (LMPs), which enforce viral latency. Azidothymidine (AZT), a thymidine analogue, is an excellent substrate for EBV thymidine kinase, and is capable of inducing EBV lytic gene expression and apoptosis in primary Type I latency EBV+ Burkitt lymphoma (BL) cell lines. AZT was initially developed as an antineoplastic agent but was found to have low efficacy due to poor affinity to human DNA polymerase and low incorporation into DNA. The chemotherapy drug methotrexate (MTX), which also induces gamma-herpes virus lytic induction, inhibits thymidylate synthase thus blocking de novo synthesis of dTMP increasing the likelihood of AZT incorporation into DNA. Indeed, the combination of high-dose MTX and AZT was found to be clinically efficacious in HIV-infected patients with aggressive relapsed NHL. Similarly, at the University of Miami, we have found this drug combination to be highly effective when used in patients with aggressive gamma-herpes virus lymphomas including EBV+ BL and human herpes virus 8 (HHV-8) related primary effusion lymphoma (solid PEL). We report here the role of high dose MTX plus intravenous AZT with alternating infusional EPOCH (etoposide, prednisone, vincristine, cyclophosphamide, and adriamycin) in the treatment of HIV associated EBV+ plasmablastic lymphoma. MethodsThree HIV+ patients with biopsy proven, EBV-encoded RNA (EBER)+ PBL in sino-oral mucosa were treated with high dose methotrexate (4.5 g/m2 IV on day 1) and AZT 1.5 g IV infusion q12 hours (days 1-3) alternating with dose-adjusted (DA) EPOCH chemotherapy for 6-8 cycles as first line therapy. Patients were started/kept on HAART and were administered prophylactic intrathecal MTX±cytarabine. Responses were evaluated by oral exam and CT scans. ResultsSelected characteristics of patients are demonstrated in Table. Only Patient 2 was on HAART at the time of diagnosis. Patient 1 had intracranial extension of the large left maxillary lesion through sphenoid sinus with negative CSF cytology. All patients treated with HD-MTX/AZT and alternating EPOCH as above achieved a complete remission (CR). Patient 1 achieved CR after the 3rd cycle. However, 19 days after the 4th cycle he was found to have local recurrence, which was thought to be secondary to poor chemotherapy penetration to necrotic oral palate tissue, and was administered a total of 4620 cGy intensity-modulated radiotherapy to head and neck region followed by consolidation with the same chemotherapy regimen for 4 more cycles. He remains alive and free of disease after 14 months. Patient 2 and 3 received a total of 6 cycles of chemotherapy and remain disease-free after 12 and 13 months, respectively. No grade ≥3 toxicities were encountered during the treatment. ConclusionThe combination of high dose MTX and AZT plus alternating DA-EPOCH chemotherapy is a tolerable and effective treatment for HIV related EBV+ plasmablastic lymphomas. The combination of MTX and AZT is a highly active, EBV lytic inducing and targeted regimen which deserves further investigation in the treatment of gamma-herpes virus associated malignancies.NoSexAge at dxCD4 at dxLDH (normal<618)Stage# of cyclesDFS (from dx)1M52571300IIB4 + IMRT + 4>14 mos2F33102638IIA6>12 mos3M44339450IIA6>13mos Disclosures:No relevant conflicts of interest to declare.

Short-Term Exposure to Arginine Butyrate, in Combination with Ganciclovir, Is as Effective as Continuous Exposure for Virus-Targeted Therapy of EBV-Positive Lymphomas.

Abstract 4754Antiviral drugs alone have been unsuccessful in the treatment of Epstein-Barr virus (EBV)-associated malignancies because the virus maintains a latent state of replication in these tumors. In recent years, we developed a novel therapeutic approach wherein the early lytic phase of the virus is induced prior to the use of cytotoxic antiviral drugs. Butyrate derivatives induce an early lytic pattern of EBV gene expression in patient-derived EBV-positive lymphoblastoid cell lines and, together with the nucleoside analog ganciclovir (GCV), effectively reduce or eliminate tumor growth in humans. In a completed Phase 1/2 trial in which patients with relapsed or refractory EBV-associated lymphoid malignancies were treated with 3 weeks of Arginine Butyrate combined with GCV, tumor responses (CR and PR) occurred in 10 of 15 patients. Butyrate requires administration by prolonged intravenous infusion, which is challenging over long time periods. In the Phase 1/2 clinical trial, tumor responses were observed within a few days of starting therapy. We therefore investigated whether brief or discontinuous exposure to Butyrate is also capable of initiating early lytic-phase gene expression and thymidine kinase induction, and sensitizing EBV-positive lymphoma cells to ganciclovir-mediated cell growth arrest and apoptosis. Multiple daily 6-hr exposures of the EBV-positive Burkitt's lymphoma cell line P3HR1 to butyrate induced sustained expression of the EBV TK and lytic-phase protein BMRF. Discontinuous exposure to butyrate in combination with ganciclovir also induced a similar level of tumor cell death as did continuous treatment, as measured by serial enumeration of viable cells, MTT cell proliferation assays, and measurement of cellular DNA content. Based on these observations, we have initiated a new clinical trial utilizing a 5-day infusion of Arginine Butyrate and 21 days of GCV/valganciclovir for treatment of patients with EBV-positive lymphoid malignancies. The first patient enrolled, with Rituximab-refractory EBV-positive PTLD following a cord stem cell transplant for Hodgkin's Disease, has been treated on this protocol. The therapy was well-tolerated and resulted in rapid resolution of fever and cough of several weeks duration, and a rapid decrease of markedly elevated LDH levels to the normal range. At the end of the first cycle, 4 of 6 target lesions resolved completely, and two additional lesions decreased in size. High EBV, CMV and HHV6 viral loads became undetectable. This response has been durable for 2 months. These findings together suggest that a shorter, more patient-accessible regimen of this virus-targeted therapeutic strategy may be efficacious, and the clinical trial is continuing. Disclosures:Faller:HemaQuest Pharmaceuticals: Consultancy, Equity Ownership, Patents & Royalties, Research Funding. Off Label Use: The use of Ganciclovir, administered in combination with Arginine Butyrate as an inducer of viral TK,to induce apoptosis in EBV-lymphoma and EBV lymphoproliferative disease. Ghosh:HemaQuest Pharmaceuticals: Research Funding. Lerner:HemaQuest Pharmaceuticals: Consultancy. Berenson:HemaQuest Pharmaceuticals: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Perrine:HemaQuest Pharmaceuticals: Employment, Equity Ownership, Patents & Royalties, Research Funding.

O121. Profiling of epstein-barr virus gene expression pattern in oral squamous cell carcinoma for assessing viral tumorigenic factor

O121. Profiling of epstein-barr virus gene expression pattern in oral squamous cell carcinoma for assessing viral tumorigenic factor

Immune activation suppresses initiation of lytic Epstein-Barr virus infection

Primary infection with Epstein-Barr virus (EBV) is asymptomatic in children with immature immune systems but may manifest as infectious mononucleosis, a vigorous immune activation, in adolescents or adults with mature immune systems. Infectious mononucleosis and chronic immune activation are linked to increased risk for EBV-associated lymphoma. Here we show that EBV initiates progressive lytic infection by expression of BZLF-1 and the late lytic genes gp85 and gp350/220 in cord blood mononuclear cells (CBMC) but not in peripheral blood mononuclear cells (PBMC) from EBV-naive adults after EBV infection ex vivo. Lower levels of proinflammatory cytokines in CBMC, used to model a state of minimal immune activation and immature immunity, than in PBMC were associated with lytic EBV infection. Triggering the innate immunity specifically via Toll-like receptor-9 of B cells substantially suppressed BZLF-1 mRNA expression in acute EBV infection ex vivo and in anti-IgG-stimulated chronically latently EBV-infected Akata Burkitt lymphoma cells. This was mediated in part by IL-12 and IFN-gamma. These results identify immune activation as critical factor for the suppression of initiation of lytic EBV infection. We hypothesize that immune activation contributes to EBV-associated lymphomagenesis by suppressing lytic EBV and in turn promotes latent EBV with transformation potential.

Short, discontinuous exposure to butyrate effectively sensitizes latently EBV-infected lymphoma cells to nucleoside analogue antiviral agents

Antiviral drugs alone have been unsuccessful in the treatment of Epstein–Barr virus (EBV)-associated malignancies because the virus maintains a latent state of replication in these tumors. In recent years, novel therapeutic approaches are being investigated wherein lytic replication of the virus is induced prior to the use of cytotoxic antiviral drugs. The choice of suitable agents to induce lytic replication has been a critical step in this novel approach. We have previously demonstrated that butyrate derivatives induce a lytic pattern of EBV gene expression in patient-derived EBV-positive lymphoblastoid cell lines and, together with nucleoside analog ganciclovir, effectively reduce or eliminate tumor growth in humans. Butyrate has drawbacks as a therapeutic agent, however, as constant intravenous infusion is required to achieve detectable plasma levels of this drug. In this study, we investigated whether discontinuous exposure to butyrate is capable of initiating lytic phase gene expression and thymidine kinase induction, and sensitizing EBV-positive lymphoma cells to ganciclovir-mediated cell growth arrest and apoptosis. We demonstrate that multiple daily 6-h exposures of the EBV-positive Burkitt's lymphoma cell line P3HR1 to butyrate induced sustained expression of the EBV lytic phase protein BMRF. Viral thymidine kinase was also induced by intermittent exposure, although to a lower level than with continuous exposure treatment. However, discontinuous exposure to butyrate in combination with ganciclovir induced a similar level of tumor cell growth inhibition as did continuous treatment, as measured by serial enumeration of viable cells, MTT cell proliferation assays and measurement of cellular DNA content. We further demonstrated that those cells which survived initial exposure to butyrate plus ganciclovir remained susceptible to further cycles of combination treatment. These findings suggests that continuous infusion of butyrate may not be necessary for maintaining viral thymidine kinase gene expression and sensitization to antiviral agents in EBV-associated tumors, and that therapeutic regimens which employ more convenient, discontinuous exposure to butyrate may also be effective clinically.

Detection of Epstein–Barr virus infection and gene expression in human tumors by microarray analysis

Epstein–Barr virus (EBV) genome-chips are employed to determine the EBV infection rate and to reveal the gene expression patterns of EBV in tumor biopsies. These chips are produced with 71 consecutive PCR-amplified EBV DNA fragments of 1–3 kbp covering the entire EBV genome. The specificity of the EBV-chips is determined by hybridizing the DNA on the chips with biotin-labeled cDNA probes reverse transcribed from the mRNA of P3HR1 cells, which were B-cell infected latently by EBV. Hybridization results revealed only the expression of EBNA1, EBNA2, EBER1 and EBER2 in these cells. On the other hand, EBV lytic genes are expressed after the cells are treated with 12- O-tetradecanoylphorbol-13-acetate and sodium butyrate to induce the EBV lytic cycle. Fourty-four tumor biopsies from different organs are assayed with these chips, which showed many defined and interesting EBV gene expression patterns. This study demonstrates that the EBV-chip is useful for screening infection with EBV in tumors, which may lead to insights into tumorigenesis associated with this virus.

Epstein–Barr virus-encoded LMP2A regulates viral and cellular gene expression by modulation of the NF-κB transcription factor pathway

Epstein-Barr virus (EBV)-associated malignancies display distinct patterns of virus latent gene expression that reflect the complex interplay between the virus and its host cell. In the EBV-associated epithelial tumor nasopharyngeal carcinoma (NPC), the virus-encoded latent membrane protein LMP2A is consistently expressed whereas the oncogenic LMP1 protein appears to be restricted to only a proportion of tumors. In an attempt to understand the contribution of LMP2A to the pathogenesis of NPC, we established carcinoma cell lines stably infected in vitro with either a wild-type recombinant EBV (rEBV) or a mutant rEBV in which LMP2A is deleted (rEBV-2A). An NPC-like pattern of EBV gene expression including LMP2A but not LMP1 was consistently observed in carcinoma cells infected with rEBV. However, carcinoma cells infected with rEBV-2A expressed high levels of LMP1 from the signal transducer and activator of transcription (STAT)-regulated L1-TR promoter. Consistent with this effect, basal STAT activity was reduced in rEBV-infected carcinoma cells, and this repression was relieved in the absence of LMP2A. This modulation of STAT activity correlated with the ability of LMP2A to inhibit the autocrine secretion of IL-6 from carcinoma cell lines. Exogenous IL-6 was able to induce expression of LMP1 by means of STAT3 activation both in rEBV-infected carcinoma cell lines and in the EBV-positive C666-1 NPC cell line. The LMP2A-mediated suppression of IL-6 was a consequence of NF-kappaB inhibition. These data reveal that LMP2A modulates two key transcription factor pathways in carcinoma cells and suggest that this finding may be important in the pathogenesis of EBV-associated tumors.

A naturally derived gastric cancer cell line shows latency I Epstein–Barr virus infection closely resembling EBV-associated gastric cancer

In a process seeking out a good model cell line for Epstein–Barr virus (EBV)-associated gastric cancer, we found that one previously established gastric adenocarcinoma cell line is infected with type 1 EBV. This SNU-719 cell line from a Korean patient expressed cytokeratin without CD19 or CD21 expression. In SNU-719, EBNA1 and LMP2A were expressed, while LMP1 and EBNA2 were not. None of the tested lytic EBV proteins were detected in this cell line unless stimulated with phorbol ester. EBV infection was also shown in the original carcinoma tissue of SNU-719 cell line. Our results support the possibility of a CD21-independent EBV infection of gastric epithelial cells in vivo. As the latent EBV gene expression pattern of SNU-719 closely resembles that of the EBV-associated gastric cancer, this naturally derived cell line may serve as a valuable model system to clarify the precise role of EBV in gastric carcinogenesis.

Target cells of Epstein-Barr-virus (EBV)-positive post-transplant lymphoproliferative disease: similarities to EBV-positive Hodgkin's lymphoma

Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disease (PTLD) encompasses a histologically broad range of lesions, arising from the expanded pool of EBV-infected B cells in the immunocompromised host. Identification of the precise cellular origin of these tumours could clarify their pathogenesis. Of 13 cases of EBV-positive cases of PTLD characterised by histological analysis, pattern of EBV gene expression, and clinical course, 11 had monoclonal or biclonal lesions in which we determined the progenitor B cell by immunoglobulin heavy chain (IgH) genotyping. Two tumours had a naive B cell genotype and two showed patterns of IgH somatic mutation typical of antigen-selected (post-germinal-centre) memory cells. All four arose early post-transplant and expressed the markers of EBV transformation--Epstein-Barr nuclear antigen (EBNA) 2 and latent membrane protein (LMP) 1. However, seven tumours, either of early or late onset and including some with downregulated EBNA 2 and LMP 1, arose from post-germinal cells with randomly mutated or sterile IgH genotypes usually incompatible with B-cell survival in vivo. PTLD can arise from a broad range of target B cells and not only from the pool of antigen-selected memory cells that EBV generally colonises in immunocompetent individuals. Tumour development seems frequently associated with the EBV-induced rescue and expansion of B cells that have failed the physiological process of germinal centre selection into memory. This finding shows an unexpected connection between pathogenesis of PTLD and that of EBV-positive Hodgkin's lymphoma, another B-cell malignancy of atypical post-germinal-centre cell origin.