Epithelial cell retention of transcriptionally active, P3HR-1-derived heterogeneous Epstein-Barr virus DNA with concurrent loss of parental virus.

Deleted, rearranged, heterogeneous (het) Epstein-Barr virus (EBV) DNA with the distinctive capability of disrupting EBV latency has been reported in biopsy samples of EBV-associated tumors whose onset in immunocompetent hosts is characteristically preceded by an antibody response indicative of EBV reactivation. Using the EBV P3HR-1 strain, we have reproduced in long-term culture of SVK epithelial cells an unusual pattern of infection previously observed in a subset of tumor biopsy samples: the persistence of het DNA in the absence of the parental helper virus. Fluorescence in situ hybridization (FISH) of infected cell subclones indicated the retention of het DNA in an integrated form.

Augmented latent membrane protein 1 expression from Epstein-Barr virus episomes with minimal terminal repeats.

The major oncogene of the Epstein-Barr virus (EBV), latent membrane protein 1 (LMP1), can be expressed from either of two promoters, ED-L1 or L1-TR, producing mRNAs of 2.8 kb or 3.5 kb, respectively.

Points of recombination in Epstein-Barr virus (EBV) strain P3HR-1-derived heterogeneous DNA as indexes to EBV DNA recombinogenic events in vivo.

Deletions and rearrangements in the genome of Epstein-Barr virus (EBV) strain P3HR-1 generate subgenomic infectious particles that, unlike defective interfering particles in other viral systems, enhance rather than restrict EBV replication in vitro. Reports of comparable heterogeneous (het) DNA in EBV-linked human diseases, based on detection of an abnormal juxtaposition of EBV DNA fragments BamHI W and BamHI Z that disrupts viral latency, prompted us to determine at the nucleotide level all remaining recombination joints formed by the four constituent segments of P3HR-1-derived het DNA. Guided by endonuclease restriction maps, we chose PCR primer pairs that approximated and framed junctions creating the unique BamHI M/B1 and E/S fusion fragments.

A replication-defective gammaherpesvirus efficiently establishes long-term latency in macrophages but not in B cells in vivo.

Murine gammaherpesvirus 68 (gammaHV68 or MHV68) is genetically related to the human gammaherpesviruses Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV), providing a useful system for in vivo studies of the virus-host relationship. To begin to address fundamental questions about the mechanisms of the establishment of gammaherpesvirus latency, we previously generated a replication-defective gammaHV68 lacking the expression of the single-stranded DNA binding protein encoded by orf6. In work presented here, we demonstrate that this mutant virus established a long-term infection in vivo that was molecularly identical to wild-type virus latency.

Modulation of the cell growth regulator mTOR by Epstein-Barr virus-encoded LMP2A.

Control of translation initiation is one means by which cells regulate growth and proliferation, with components of the protein-synthesizing machinery having oncogenic potential. Expression of latency protein LMP2A by the human tumor virus Epstein-Barr virus (EBV) activates phosphatidylinositol 3-kinase/Akt located upstream of an essential mediator of growth signals, mTOR (mammalian target of rapamycin). We show that mTOR is activated by expression of LMP2A in carcinoma cells, leading to wortmannin- and rapamycin-sensitive inhibition of the negative regulator of translation, eukaryotic initiation factor 4E-binding protein 1, and increased c-Myc protein translation.

Reactive oxygen signaling and MAPK activation distinguish Epstein-Barr Virus (EBV)-positive versus EBV-negative Burkitt's lymphoma.

Burkitt's lymphoma (BL) is an aggressive B cell neoplasm, which is one of the most common neoplasms of childhood. It is highly widespread in East Africa, where it appears in endemic form associated with Epstein-Barr virus (EBV) infection, and around the world in a sporadic form in which EBV infection is much less common. In addition to being the first human neoplasm to be associated with EBV, BL is associated with a characteristic translocation, in which the Ig promoter is translocated to constitutively activate the c-myc oncogene.

Cytotoxic T lymphocyte therapy for Epstein-Barr virus+ Hodgkin's disease.

Epstein Barr virus (EBV)+ Hodgkin's disease (HD) expresses clearly identified tumor antigens derived from the virus and could, in principle, be a target for adoptive immunotherapy with viral antigen-specific T cells. However, like most tumor-associated antigens in immunocompetent hosts, these potential targets are only weakly immunogenic, consisting primarily of the latent membrane protein (LMP)1 and LMP2 antigens. Moreover, Hodgkin tumors possess a range of tumor evasion strategies.

Epstein-Barr virus-encoded LMP2A regulates viral and cellular gene expression by modulation of the NF-kappaB 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).

Peripheral blood lymphocytes express recombination-activating genes 1 and 2 during Epstein-Barr virus-induced infectious mononucleosis.

Implicit in the persistence of Epstein-Barr virus (EBV) in B lymphocytes is the successful circumvention of ongoing cell selection for competence of B cell receptors (BCRs). Because the EBV infection of B cells in vitro induces enzymatic machinery that is responsible for secondary immunoglobulin gene rearrangement, we examined the expression of the recombination-activating genes (RAGs) in peripheral blood mononuclear cells (PBMCs) from 26 patients with infectious mononucleosis (IM). RAG1 and/or RAG2 RNA was detected in PBMCs from 42% of patients with IM but not from healthy control subjects.

Length of Epstein-Barr virus termini as a determinant of epithelial cell clonal emergence.

Reiterated terminal sequences of Epstein-Barr virus (EBV) DNA are numerically heterogeneous among infectious virions, providing a viral measure of clonality in infected cells. After in vitro infection, carcinoma cells bearing EBV episomes with fewer terminal repeats (TRs) proliferated faster. In single-cell clones, TR number varied inversely to the quantity of latent membrane protein 2A (LMP2A) transcripts whose unspliced precursors cross joined TRs.

A defective, rearranged Epstein-Barr virus genome in EBER-negative and EBER-positive Hodgkin's disease.

A ubiquitous herpesvirus that establishes life-long infection, the Epstein-Barr virus (EBV) has yielded little insight into how a single agent in general accord with its host can produce diverse pathologies ranging from oral hairy leukoplakia to nasopharyngeal carcinoma, from infectious mononucleosis to Hodgkin's disease (HD) and Burkitt's lymphoma. Its pathogenesis is further confounded by the less than total association of virus with histologically similar tumors. In other viral systems, defective (interfering) viral genomes are known to modulate outcome of infection, with either ameliorating or intensifying effects on disease processes initiated by prototype strains.

Oral cefixime is similar to continued intravenous antibiotics in the empirical treatment of febrile neutropenic children with cancer.

Empiric oral antibiotic therapy for febrile neutropenic cancer patients has been suggested as a means to decrease hospitalization, but the safety of this approach has not been adequately studied in children. We compared continued iv antibiotic therapy with switching treatment to orally administered cefixime in a group of selected febrile neutropenic children for whom blood cultures were sterile after 48 h of incubation. Two hundred episodes of febrile neutropenia were studied (156 patients), and 100 episodes were randomized to receive each treatment.

Epstein-Barr virus-targeted therapy for AIDS-related primary lymphoma of the central nervous system.

Epstein-Barr virus (EBV) targeted therapeutic strategies for viral associated malignant diseases have received only perfunctory consideration, first, because latent herpesviruses have been intractable to antiviral chemotherapy and, second, because the role EBV has in maintenance of the malignant cell phenotype has been uncertain. Two patients with EBV related primary central nervous system lymphoma (PCNSL) in the setting of advanced AIDS, were treated with low dose hydroxyurea based on in vitro anti-EBV activity. The responses obtained here suggest the promise of antiviral approaches in select cancers.

Epstein-Barr virus infection in salivary gland tumors in children and young adults.

Background: Epstein-Barr virus (EBV) infection has been implicated in the pathogenesis of certain subtypes of salivary gland tumors in the adult population. However, to the authors' knowledge its role in pediatric salivary gland tumors, a rare disease, has not been explored previously.

Methods: Thirteen cases of primary tumors of the salivary gland occurring in children were retrieved from the tumor registry at the St.

Molecular evidence of ocular Epstein-Barr virus infection.

Ocular manifestations have been attributed to the Epstein-Barr virus (EBV), largely on the basis of seroepidemiologic data. Two patients who developed conjunctival disease as the presenting feature of EBV infection are reported, each confirmed by in situ hybridization of EBV genome in affected tissue biopsy specimens. Recognition of EBV-induced ocular disease as an initial presentation of clinical EBV infection is important to the practitioner because of the ubiquitous nature of this herpesvirus.

Patterned entry and egress by Epstein-Barr virus in polarized CR2-positive epithelial cells.

In polarized epithelium direction of viral entry and release correlates with proclivity of a virus to establish local versus systemic infection. The Epstein-Barr virus (EBV), whose principal tissue reservoir is B lymphocytes, also has disease manifestations in epithelium, suggesting intertissue spread potentially influenced by epithelial cell polarity. We stably transfected the B lymphocyte EBV receptor (CR2/CD21) into Madin-Darby canine kidney (MDCK) epithelial cells used extensively to study effects of cell polarity on infection by both DNA and RNA viruses.

Large proportion of Epstein-Barr virus-associated small noncleaved cell lymphomas among children with non-Hodgkin's lymphoma at a single institution in Moscow, Russia.

To evaluate clinical and biologic features of children with non-Hodgkin's lymphoma (NHL) treated in Moscow, Russia, we studied 53 cases treated in the Republican Children's Hospital from 1990 to 1994. Histologic examination disclosed a predominance of the small noncleaved cell subtype (32 cases, 60%); a smaller percentage of the lymphoblastic and large-cell subtypes (14 cases, 26% and 7 cases, 13%, respectively) were identified. The frequencies of primary sites of involvement in descending order included 60% in abdomen, 19% in mediastinum, 15% in head/neck, and 4% in peripheral nodes.

Infusion of cytotoxic T cells for the prevention and treatment of Epstein-Barr virus-induced lymphoma in allogeneic transplant recipients.

Epstein-Barr virus (EBV) causes potentially lethal immunoblastic lymphoma in up to 25% of children receiving bone marrow transplants from unrelated or HLA-mismatched donors. Because this complication appears to stem from a deficiency of EBV-specific cytotoxic T cells, we assessed the safety and efficacy of donor-derived polyclonal (CD4(+) and CD8(+)) T-cell lines as immunoprophylaxis and treatment for EBV-related lymphoma. Thirty-nine patients considered to be at high risk for EBV-induced lymphoma each received 2 to 4 intravenous infusions of donor-derived EBV-specific T lymphocytes, after they had received T-cell-depleted bone marrow from HLA-matched unrelated donors (n = 33) or mismatched family members (n = 6).

Primary central nervous system lymphoma in a child with acute B-cell lymphoblastic leukaemia: consecutive Epstein-Barr virus-related malignancies.

Primary central nervous system lymphoma (PCNSL), observed among immunocompromised AIDS patients, has not been reported during chemotherapy for acute lymphoblastic leukaemia (ALL). We report a case of PCNSL occurring in a child receiving intensive multiagent chemotherapy for B-cell ALL. In situ hybridization studies demonstrated Epstein-Barr virus genome in both tumours, suggesting a possible link between the two diseases.

Spontaneous loss of viral episomes accompanying Epstein-Barr virus reactivation in a Burkitt's lymphoma cell line.

Life-long viral persistence is a hallmark of human herpesvirus infection. In the Epstein-Barr virus (EBV)-positive Burkitt's lymphoma (BL) cell line, Mutu, spontaneous loss of all viral episomes accompanied productive viral DNA replication. The molecular configuration of intracellular EBV DNA evolved from monoclonal episomes in cells retaining the original tumor phenotype to predominantly replicating linear DNA and, subsequently, only integrated forms in BL cells that had acquired the lymphoblastoid cell phenotype.

Eradication of latent Epstein-Barr virus by hydroxyurea alters the growth-transformed cell phenotype.

The hallmark of infection by human herpesviruses, life-long persistence in the host, is unaffected by current antiviral therapies effective against replication of virus. In vitro studies indicated that low concentrations of the ribonucleotide reductase inhibitor, hydroxyurea, completely eliminated Epstein-Barr virus (EBV) episomes from latently infected Burkitt's lymphoma (BL) cell subsets, providing the first example of chemotherapeutic eradication of a latent herpesvirus from any cell population. Unlike parental EBV-positive BL cells, virus-free cell progeny from one treated cell line no longer exhibited the malignant phenotype in tumorigenicity assays.

Epstein-Barr virus (EBV)-specific cytotoxic T lymphocytes for the treatment of patients with EBV-positive relapsed Hodgkin's disease.

Adoptive transfer of Epstein-Barr virus (EBV)-specific cytotoxic T lymphocytes (CTLs) is effective prophylaxis and treatment of EBV-positive immunoblastic lymphoma in immunocompromised patients. In 50% of patients with Hodgkin's disease, the tumor cells are EBV antigen-positive and may therefore also be suitable targets for treatment with virus-specific CTLs. However, Hodgkin's disease may produce several inhibitory effects on immune induction and effector function in vivo, which may preclude the generation or effector function of CTLs reactive against EBV viral proteins, including those expressed by the tumor cells.

Acute Epstein-Barr virus infection complicated by severe thrombocytopenia.

We describe one patient with acute Epstein-Barr virus (EBV) infection associated with severe thrombocytopenia and review 36 additional cases reported in the literature. Complications of EBV infection due to severe thrombocytopenia occurred in 10 (27.0%) of 37 patients, and 2 (5.

Predominance and characteristics of Burkitt lymphoma among children with non-Hodgkin lymphoma in northeastern Brazil.

The purpose of this paper was to define the histologic distribution, clinical features, and treatment response of childhood non-Hodgkin lymphoma (NHL) in northeastern Brazil. We reviewed medical records and histopathologic studies of 98 children treated for NHL from 1980 to 1987 at a major pediatric cancer center in Recife, Brazil. Treatment outcome was evaluated in relation to tumor burden (stage and serum LDH) and type of therapy (LSA2L2 vs other multiagent chemotherapy).

Epstein-Barr virus in pediatric Hodgkin disease: age and histiotype are more predictive than geographic region.

Epidemiologic studies have implicated Epstein-Barr virus (EBV) in the great majority (80%-100%) of Hodgkin disease (HD) cases in South American countries, versus only 30%-40% in the United States and other industrialized countries. Other EBV-related malignancies are known to be geographically localized, including nasopharyngeal carcinoma in south China and Burkitt lymphoma in equatorial Africa. Some studies, however, have suggested that age and histiotype, rather than geographic region, are the major determinants of the association between EBV and HD.