Showing papers on "Gammaherpesvirinae published in 1989"

Expression of Epstein-Barr virus transformation-associated genes in tissues of patients with EBV lymphoproliferative disease.

Abstract: Epstein-Barr virus (EBV) has been associated with serious or fatal lymphoproliferative disease in immunocompromised patients. EBV nuclear protein 2 and latent membrane protein are characteristically expressed in B lymphocytes proliferating in vitro in response to growth transformation by EBV. These two proteins are thought to be effectors of lymphocyte growth since they increase the expression of B-lymphocyte activation (CD23) and cell-adhesion (LFA 3 and ICAM 1) molecules in vitro. Using monoclonal antibody-immune microscopy, we have demonstrated that these two EBV proteins and their associated B-lymphocyte activation or adhesion molecules are expressed in the infiltrating B lymphocytes in immunocompromised patients with EBV lymphoproliferative disease. These monoclonal antibodies should be useful in the early diagnosis of EBV lymphoproliferative disease and in distinguishing it from other B-lymphocyte cancers associated with EBV, such as Burkitt's lymphoma. The finding of EBV nuclear protein 2 and latent membrane protein and their associated activation or adhesion molecules provides a further pathophysiologic link between EBV and the proliferation of B lymphocytes in immunocompromised patients.

Latent and Replicating Forms of Epstein-Barr Virus DNA in Lymphomas and Lymphoproliferative Diseases

Abstract: Epstein-Barr virus (EBV) is associated with lymphomas and lymphoproliferative diseases that occur mainly in immunocompromised patients, but the role EBV plays in their pathogenesis is unclear. The evidence linking EBV etiologically to these disorders includes the presence of EBV DNA and nuclear antigens in the lesions and serologic evidence that some patients with these lesions are experiencing primary or reactivated EBV infections. These syndromes may represent proliferation of cells latently infected with EBV, but the possibility of viral replication has not been rigorously studied. DNA extracted from biopsies of 35 lymphoproliferative diseases was probed with regions of the EBV genome capable of distinguishing circular, episomal DNA found in latency from linear, replicating EBV DNA. All samples contained restriction fragments characteristic of fused termini, indicative of circular, latent genomes. Thirteen samples contained additional restriction fragments diagnostic of linear EBV DNA. Therefore, replicating EBV DNA is found in ^40^0 of EBV-associated lymphoproliferative disorders. Epstein-Barr virus (EBV) can manifest two different life cycles: latent and replicative. In lymphoid cells in tissue culture, EBV is predominantly latent: The cells grow continuously, the genome is maintained at a constant copy number within the cell, a limited number of regions of the genome are transcribed, and a relatively small number of EBV-associated proteins (latent membrane and nuclear antigens) are pro

Herpesvirus Diseases of Cattle, Horses, and Pigs

Abstract: 1. Infectious Bovine Rhinotracheitis/Vulvovaginitis (BHV 1).- 2. Bovine Herpesvirus 2 Infection.- 3. Bovine Herpesvirus-4 (BHV 4) Infections of Cattle.- 4. Malignant Catarrhal Fever and the Gammaherpesvirinae of Bovidae.- 5. Aujeszky's Disease in Ruminants.- 6. Herpesviral Diseases of the Horse.- 7. Aujeszky's Disease (Pseudorabies) in Pigs.- 8. Porcine Cytomegalovirus.

Deletion mutants of herpesvirus saimiri define an open reading frame necessary for transformation.

Abstract: Analysis of a 5,549-base-pair sequence at the left end of herpesvirus saimiri unique (L-) DNA revealed two open reading frames and genes for five small nuclear U RNAs (herpesvirus saimiri U RNAs). Replication-competent deletion mutants were constructed in order to assess the importance of these genetic features for transformation by this oncogenic herpesvirus. Although not required for replication, one of the open reading frames was found to be required for immortalization of marmoset T lymphocytes into continuously growing cell lines. The protein predicted by this reading frame (STP; saimiri transformation-associated protein) has a highly hydrophobic stretch of 26 amino acids sufficient for a membrane-spanning domain near its carboxy terminus; this domain is immediately preceded by a sequence appropriate for formation of a metal-binding domain (His X2 His X6 Cys X2 Cys, where Xs are other amino acids). One of two poly(A)+ RNAs that could encode STP is bicistronic, while the other has a long 5' untranslated region (approximately 1.5 kilobases). Although some analogies can be drawn between STP and LMP (lymphocyte membrane protein) of Epstein-Barr virus, STP is not related in sequence to LMP.

Herpesvirus saimiri strains from three DNA subgroups have different oncogenic potentials in New Zealand white rabbits

Abstract: Herpesvirus saimiri is a primate tumor virus that induces acute T-cell lymphomas in New World monkeys. Strains of this virus have been previously classified into three groups on the basis of extreme DNA variability of the rightmost region of unique L-DNA. To compare the oncogenic potentials of various strains, we inoculated New Zealand White rabbits with viruses representing groups A, B, and C of herpesvirus saimiri. The results showed that a group C strain were highly oncogenic in New Zealand White rabbits; however, group A or B viruses were not oncogenic in these rabbits. Analysis of DNAs of tumor tissues and lymphoid cell lines established from tumors showed that the viral genome exists in circular episomal form. To identify which part of the genome of the group C strain is responsible for the highly oncogenic phenotype, group B-C recombinant strains were constructed by an efficient drug selection technique. Two group B recombinant strains in which the right-end 9.2 kilobase pairs of unique DNA is replaced by group C virus DNA were oncogenic in rabbits, indicating that the rightmost sequences contribute to the oncogenic properties of the group C strain. Oncogenicity of herpesvirus saimiri has been traditionally evaluated in New World monkeys; infection of rabbits with group C strain 484-77 offers a much more accessible animal model to study the mechanism of oncogenicity of this virus.

Epstein-Barr virus gene expression in malignant lymphomas induced by experimental virus infection of cottontop tamarins.

Abstract: Inoculation of cottontop tamarins with a large dose of Epstein-Barr virus (EBV) leads to the induction of multiple EBV genome-positive lymphomas. These tumors have been characterized as oligoclonal or monoclonal large-cell malignant lymphomas that closely resemble the EBV genome-positive B-cell lymphomas that arise in human allograft recipients. The expression of latent and lytic EBV-encoded proteins was investigated in these virus-induced tamarin lymphomas and in derived cell lines. The tamarin tumors were found to express EBV nuclear antigen 1 (EBNA 1), EBNA 2, EBNA leader protein, and the latent membrane protein (LMP) as determined both by immunohistochemical staining and by immunoblotting. However, within the limits of the immunoblotting assays, no expression of the EBNA 3a protein family could be detected. Assays for lytic-cycle proteins by using both polyclonal human sera and monoclonal antibodies against viral capsid antigen, early antigen, and membrane antigen (gp340/220) showed minimal, if any, expression of these antigens in the lymphoma biopsies. In contrast, the cell lines derived from these lymphomas, even in early passage, expressed abundant levels of the lytic-cycle antigens and also expressed the EBNA 3a protein as well as EBNA 1, EBNA 2, EBNA leader protein, and LMP. This finding suggests that the virus-lymphoma cell interaction, in particular the switch to lytic cycle, is subject to some form of host control in vivo. The expression of EBNA 2 and LMP in these tamarin lymphomas strengthens their resemblance to posttransplant lymphomas in humans, since these human tumors are also EBNA 2 and LMP positive (L. S. Young, C. Alfieri, K. Hennessy, H. Evans, C. O'Hara, K. Anderson, A. Rickinson, E. Kieff, and J. I. Cohen, submitted for publication). Since both proteins are known to be important effector molecules of virus-induced B-cell growth transformation in vitro, their expression in these lymphomas constitutes the best evidence for a direct oncogenic role for EBV in vivo.

Epstein-Barr virus latent infection membrane protein increases vimentin expression in human B-cell lines.

Abstract: Latent Epstein-Barr virus (EBV) infection activates B-lymphocyte proliferation through mechanisms which are partially known One approach to further delineate these mechanisms is to identify cellular genes whose expression is augmented in cells latently infected with EBV Since EBV-negative Burkitt's lymphoma cells can be grown in continuous culture and EBV can establish growth-altering latent infection in these cells, some effects of EBV on B-lymphocyte gene expression can be studied by using this in vitro system Pursuing this latter approach, we have used cDNA cloning and subtractive hybridization to identify a gene whose expression is increased after EBV infection This gene encodes the cytoskeletal protein vimentin Latent infection of established EBV-negative Burkitt's lymphoma cell lines with the transforming EBV strain, B95-8, resulted in dramatic increases in vimentin mRNA and protein levels, while infection with the nontransforming P3HR1 strain failed to do so Vimentin induction was reproduced by the expression of the single EBV gene which encodes the latent infection membrane protein (LMP) An amino-terminal LMP deletion mutant did not induce vimentin These results are of particular interest in light of the transforming potential of LMP, as demonstrated in rodent fibroblasts, and the interaction between vimentin and LMP observed in immunofluorescent colocalization and cell fractionation studies

Clonal T-cell Lymphoproliferation Containing Epstein-Barr (EB) Virus DNA in a Patient with Chronic Active EB Virus Infection

Abstract: A 10-year-old boy with chronic active Epstein-Barr virus (EBV) infection developed T-cell lymphoproliferation in the terminal stage of hepatic failure. The phenotypes of the proliferating lymphocytes were CD3+, CD4+ and HLA-DR+. The genomic DNAs from these cells demonstrated two rearranged T-cell receptor beta-chain genes and contained the EBV genome. These findings indicate that EBV can infect T lymphocytes and might cause clonal T-cell lymphoproliferation.

Partial transcription map of Marek's disease herpesvirus in lytically infected cells and lymphoblastoid cell lines

Abstract: Marek's disease herpesvirus (MDV) can cause either a productive-restrictive or lytic infection, a latent infection or can transform thymus-derived lymphocytes. RNA was extracted from infected chicken embryo fibroblasts (CEF) or from lymphoblastoid tumour cell lines. Some of the infected CEF were treated with 200 micrograms/ml cycloheximide to identify immediate early (IE) transcripts, and others with 1 microM 1-(2-fluoro-2-deoxy-B-D-arabinofuranosyl)-5-methyluracil (FMAU), an inhibitor of herpesvirus DNA synthesis to identify early transcripts. An extensive Northern blot analysis was carried out using DNA probes spanning almost the complete MDV genome. In the lytically infected CEF at least 66 discrete transcripts were detected, ranging in size from 9.1 kb to 0.6 kb. Eleven IE transcripts were identified, of which 8 were mapped in the genome segment consisting of the IRL, IRS, US and TRS. Six transcripts were identified as early genes. In the MD lymphoblastoid cell lines MDCC-HPI, a non-producer cell line, and MDCC-CU41, a non-expression cell line, 4 and 7 transcripts were detected, respectively. These RNAs were transcribed from IE genes located mainly in the repeat sequences flanking UL and US and in US. Treatment of the lymphoblastoid cell lines with 20 micrograms/ml 5-iodo-2-deoxyuridine resulted in the additional transcription of 1 RNA species in HPI and 9 in CU41. Most of the transcripts present in lytically infected cells were also detected in MDCC-CU36, a cell line with a high percentage of antigen-positive cells (expression cell line).

Selectable recombinant herpesvirus saimiri is capable of persisting in a human T-cell line.

Abstract: Strategies were developed to insert the neo resistance marker into the junction between L DNA and the right terminal repetitive H DNA of herpesvirus saimiri. Recombinant viruses were selectable in permissive epithelioid cultures. The human T-cell line Jurkat could be infected persistently with the Neor virus; the cells contained episomal viral DNA in high copy number. This selectable vector should be generally applicable for gene expression in human T cells.

Epstein-Barr virus (EBV)-containing nasopharyngeal carcinoma cells express the B-cell activation antigen blast2/CD23 and low levels of the EBV receptor CR2.

Abstract: Anaplastic nasopharyngeal carcinoma (NPC) cells invariably harbor the Epstein-Barr virus (EBV) genome, an association that is unique among human virus-associated cancers. Although EBV is able to replicate in epithelial cells, results with expression of the EBV receptor (complement receptor type 2 [CR2]; also called CD21) in normal and malignant epithelial cells are conflicting. We grew five different EBV-associated NPC tumors in nude mice, and by using a sensitive transcriptional assay, we detected a very weak transcription signal of the EBV receptor CR2 gene in these cells. This suggests that low levels of EBV receptor may be expressed by malignant epithelial nasopharyngeal cells. The gene coding for Blast2/CD23, a B-cell activation molecule induced by EBV, was transcribed in three of the transplanted NPC tumors. The soluble form of the Blast2/CD23 protein was also detected in medium taken from short-term cultures of the same NPC cell lines. In contrast to the lymphoid system, in which Blast2/CD23 expression is associated with EBV nuclear antigen (EBNA2) expression, no EBNA2 protein could be detected in these NPC epithelial cells. Our study represents the first demonstration of Blast2/CD23 expression in epithelial cells. As the soluble form of the Blast2/CD23 protein possesses growth factor activity associated with EBV-induced B-cell immortalization, these results suggest a possible role for this molecule in the pathogenesis of NPC.

A comparative analysis of the sequence of the thymidine kinase gene of a gammaherpesvirus, herpesvirus saimiri.

Abstract: Summary We present the nucleotide sequence of a region from the genome of the A + T-rich gammaherpesvirus, herpesvirus saimiri (HVS), which includes the coding sequences for the viral thymidine kinase (TK) gene. The organization of genes in this region resembles the homologous region of the Epstein-Barr virus (EBV) genome and is very compact, using overlapping coding sequences and with nucleotides shared by initiation and termination codons of neighbouring reading frames. The HVS TK is predicted to contain a 527 residue polypeptide with the first part of the presumptive nucleotide-binding site [(L, I, V)(F, Y)(I, L)(D, E)(G)(X)(X)(G)(L, I, V, M)(G)(K)(T, S)(T, S)] located at residues 212 to 224. This motif is close to the amino terminus of the TK polypeptides of alphaherpesviruses and the polypeptides of the cellular and poxvirus-encoded enzymes. The corresponding reading frame of the human gammaherpesvirus (EBV) also has a long amino-terminal extension but significant amino acid sequence similarities between the HVS and EBV sequences are not observed until the region of the nucleotide-binding site. Comparisons of these homologous carboxy-terminal sequences of the HVS- and EBV-encoded proteins with those from six alphaherpes viruses and proteins encoded by Marek's disease virus (MDV) and the herpesvirus of turkeys (HVT) confirm that the HVS and EBV sequences are products of a distinct lineage. The sequences of the MDV and HVT encoded enzymes are significantly more similar to sequences of alphaherpesvirus enzymes than to those of HVS and EBV. Comparison of these 10 highly divergent TK sequences extends and refines the identification of essential features of this family of herpesvirus enzymes and defines 19 positions at which all sequences have identical residues.

Nucleotide and predicted amino acid sequences of the Marek's disease virus and turkey herpesvirus thymidine kinase genes; comparison with thymidine kinase genes of other herpesviruses.

Abstract: In this paper we present the nucleotide sequences of the thymidine kinase (TK) genes of two avian herpesviruses: a highly oncogenic strain of Marek's disease virus (MDV strain RB1B) and its serologically related vaccine virus, the herpesvirus of turkeys (HVT strain Fc-126). The predicted coding regions of the two genes are 1029 and 1050 nucleotides respectively, corresponding to polypeptides of 343 and 350 amino acids in length. Putative nucleotide- and nucleoside-binding sites have been identified within the two predicted amino acid sequences. The MDV and HVT TK amino acid sequences exhibit 58.2% amino acid identity. Comparison with other available herpesvirus TK sequences reveals a greater homology to those of the alphaherpesviruses than to those of the gammaherpesviruses. No overall homology was found when compared with the chicken cytoplasmic TK sequence.

Analysis of human KS biopsies and cloned cell lines for cytomegalovirus, HIV-1, and other selected DNA virus sequences.

Abstract: Investigation into a possible role of several human viruses, including human cytomegalovirus (HCMV), human immunodeficiency virus (HIV-1), hepatitis B virus (HBV), human herpesvirus 6 (HHV6), and Epstein-Barr virus (EBV) in the pathogenesis of Kaposi's sarcoma (KS) has resulted in the lack of an association of these viruses in KS biopsy and cloned KS cell line specimens. Since nearly all patients with KS, including those with HIV-associated KS, have a high incidence of HCMV infection, HCMV has been proposed to be etiologically associated with KS. Moreover, our previous studies showed the retention of HCMV morphological transforming region II (mtrII) in both transformed and tumor-derived cell lines. As a result, we focused on the nucleic acid hybridization analysis of both KS biopsies from AIDS patients as well as cloned KS endothelial cell lines for HCMV mtrII sequences. We also analyzed KS biopsy and KS cloned cell line specimens for HIV-1, HBV, HHV6, and EBV sequences, since these viruses have also been...

Induction of Epstein-Barr virus in B-lymphoblastoid cells by human immunodeficiency virus type 1.

Abstract: Individuals infected with the human immunodeficiency virus (HIV), the etiologic agent of acquired immunodeficiency syndrome (AIDS), often show symptoms associated with reactivation of Epstein-Barr virus (EBV). In this study, we show that exposure of EBV-positive B lymphocytes to HIV-1 in vitro induced the EBV replicative cycle in these cells, as evidenced by an increased proportion of cells expressing EBV early antigens (EA) and capsid antigens (VCA). Reactivation of EBV by HIV-1 appeared to be virus-dose-dependent and required virus penetration and expression in B cells. Although HIV-1 RNA was detected by in situ hybridization in the majority of HIV-1-infected B lymphocytes, induction of EA and VCA was transient and limited to less than 20% of the cell population. The tumor-promoting phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and HIV-1 acted synergistically and had similar kinetics in inducing the expression of EBV. Direct reactivation of EBV by HIV-1 may contribute to the role of EBV as a factor in the genesis of AIDS-related conditions.

Genome structure of cottontail rabbit herpesvirus.

Abstract: The genome structure of a herpesvirus isolated from primary cultures of kidney cells from the cottontail rabbit Sylvilagus floridanus was elucidated by using electron microscopy and restriction enzyme analysis. The genome, which was about 150 kilobase pairs long and which had an average G + C composition of 45%, consisted of two regions with unique base sequences (54 and 47 kilobase pairs) enclosed by reiterations of a 925-base-pair sequence with a variable copy number. The internal repeats were in opposite polarity with respect to the terminal repeats, and both unique regions underwent inversion. The nucleotide sequence of the repeat unit was determined, and virion DNA termini were precisely localized within this sequence. Elements showing homology with the cleavage-packaging signals common to other herpesviruses were detected. The data indicate that this virus is different from the previously described herpesvirus sylvilagus.

Expression of interleukin 2 receptors in T cells transformed by strains of Herpesvirus saimiri representing three DNA subgroups.

Abstract: Eight T lymphoblastoid cell lines transformed by Herpesvirus saimiri were studied for requirement of interleukin 2 (IL-2) for growth in tissue culture and expression of the IL-2 receptor. The results show that four cell lines grew independent of IL-2, but four other cell lines required IL-2 for optimal growth. However, all H. saimiri transformed cells expressed IL-2 receptors, regardless of IL-2 requirement. Between 2,250 and 8,800 high-affinity receptor sites/cell were detected by ligand-binding assays; in contrast, only about 1,000 sites/cell were in an uninfected IL-2-dependent marmoset T cell line. Surface-bound IL-2 was internalized and antibodies to the receptor inhibited cell growth. Expression of IL-2 receptors may allow expansion of tumor cells in vivo in response to endogenous or exogenous IL-2.

Cytopathic effects induced by Epstein-Barr virus replication in epithelial nasopharyngeal carcinoma hybrid cells.

Abstract: NPC-KT cl.S61, a subclone derived from an epithelial-nasopharyngeal carcinoma hybrid cell line (NPC-KT), showed cytopathic changes characteristic of herpesvirus replication, including formation of multinucleated giant cells and inclusion bodies, when Epstein-Barr virus replicative cycle was induced by 5-iodo-2'-deoxyuridine. Acyclovir (an inhibitor of herpesvirus DNA polymerase), Epstein-Barr virus-immune human serum, or 2-deoxyglucose (an inhibitor of the glycosylation) interfered with syncytium formation, indicating that a virus-specified glycoprotein belonging to the late group is responsible for cell fusion induced by Epstein-Barr virus replication in cl.S61 cells.

Enhanced expression of the Epstein-Barr virus latent membrane protein by a recombinant vaccinia virus.

Abstract: SUMMARY The complete coding sequence of the Epstein-Barr virus strain B95-8 latent membrane protein (LMP) was cloned using a Raji cell cDNA library and genomic B958 DNA. The clone was characterized by sequencing and then used to make a recombinant vaccinia virus. This virus (VLMP) was shown to express a relatively high level of LMP in an authentic fashion. Antisera raised in rabbits against VLMP were shown to react with B95-8 LMP as well as cross-reacting with a 50K cellular protein. Epstein-Barr virus (EBV) is one of six known human herpesviruses and has a near ubiquitous presence in all populations. Interest in EBV has been stimulated by its association with several human cancers including Burkitt's lymphoma, polyclonal B-cell lymphoproliferations in the immunosuppressed and nasopharyngeal carcinoma. Infection of B lymphocytes with EBV in vitro leads to immortalization producing lymphoblastoid cell lines which express a restricted set of EBV genes (for reviews, see Dambaugh et al., 1986; Dillner & Kallin, 1988). Such latent gene

Sites of Epstein-Barr virus replication in acute and chronic active Epstein-Barr virus infections.

Abstract: We examined Epstein-Barr virus (EBV) in saliva samples and peripheral blood mononuclear cells (PBMC) from 9 patients with acute infectious mononucleosis (IM) and 4 patients with chronic active EBV inf

Negative modulation of Epstein-Barr virus episomes by a human B-cell growth factor.

Abstract: To study the effect of T-cell-derived BCGF-12kD on human B-cell autocrine growth-associated functions, we cultured Epstein Barr virus (EBV)-transformed normal B cells (LCL 72285) and Burkitt's lymphoma cells (Raji) in the presence or absence of BCGF-12kD. When cultured in media supplemented only with fetal calf serum, the LCL and Raji cell lines maintained relatively high levels of episomes. Although a similar level of proliferation could be maintained under defined culture conditions in media supplemented with BCGF-12kD, these conditions resulted in a time-dependent reduction of EBV sequences, as detected with EBV nuclear antigen (EBNA-1 and EBNA-2) gene probes. These results suggest that stimulation with T-cell-derived BCGF-12kD can alter a regulatory step which may be involved in the EBV transformation of B cells.

Predilection of a nasopharyngeal carcinoma-derived isolate of Epstein-Barr virus for infection of specific subsets of B lymphocytes.

Abstract: It is important to know whether there are variants of Epstein-Barr virus (EBV) with biological properties that are different from the prototype viruses that have been studied in detail, such as P3HR-1 and B95-8. We have studied an EBV isolate derived from a nasopharyngeal carcinoma (NPC) tumor, designated NPC-EBV. We have examined the target B lymphocytes infected and growth-transformed with NPC-EBV as compared with two common EBV isolates, B95-8 and AG876 EBV, for stage of maturation using antibodies to several immunoglobulin chains. Typing of the NPC-EBV transformed lymphoblastoid cell lines revealed the predilection of the NPC-EBV isolate to infect immature B lymphocytes. This was not the case for the B95-8 and AG876 isolates. The reason for the predilection of NPC-EBV for immature B lymphocytes remains to be explored further. However, these results may be important in understanding the pathophysiology of EBV-associated diseases.

Genomic difference of herpesvirus of turkeys at low and high passage levels in culture of O1 and FC126 strains.

Abstract: Serial passages in culture of herpesvirus of turkeys resulted in structural genomic changes at the regions common to two virus strains with loss of their protective ability against Marek's disease.