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M Rowe

Publications and source records attributed to M Rowe.

At least 91 records · Page 5Linked to original sources
PubMed1993

HLA-A11 epitope loss isolates of Epstein-Barr virus from a highly A11+ population.

Cytotoxic T lymphocytes (CTLs) control viral infections by recognizing viral peptides presented by major histocompatibility complex (MHC) class I molecules. Human leukocyte antigen (HLA)-A11-restricted CTLs that recognize peptide residues 416 to 424 of the Epstein-Barr virus (EBV) nuclear antigen-4 frequently dominate EBV-induced responses in A11+ Caucasian donors. This epitope is conserved in type A EBV strains from Caucasians and central African populations, where A11 is relatively infrequent. However, strains from highly A11+ populations in New Guinea carry a lysine-to-threonine mutation at residue 424 that abrogates CTL recognition and binding of the peptide to nascent A11 molecules. The results suggest that evolution of a widespread and genetically stable virus such as EBV is influenced by pressure from MHC-restricted CTL responses.

Africa↗
PubMed1993

Persistence of antibody at 18 months following vaccination of young Gambian infants with PRP-OMPC Haemophilus influenzae type b conjugate vaccine.

The rate of decline in anti-PRP antibody levels was measured in two groups of Gambian children who had been given PRP-OMPC at 1 and 3 months or 2 and 4 months of age. In the younger group (n = 70), the geometric mean titre fell from 1.32 micrograms/ml at 4 months to 0.44 micrograms/ml at 18 months. In the older group (n = 54), the geometric mean titre fell from 1.18 micrograms/ml at 5 months to 0.46 micrograms/ml at 18 months. The proportion of vaccinated children with antibody levels over 1.0 microgram/ml fell from 54% 1 month after the second dose of vaccine to 27% at the age of 18 months, while the proportion with levels over 0.15 micrograms/ml fell from 82% to 60%, with no significant differences observed between the vaccination groups. For those children who did not show evidence of environmental boosting, the half-life of anti-PRP antibody was about 100 days. This did not differ between the groups. These findings suggest that to provide lasting immunity PRP-OMPC should be given with a late booster dose at 12-15 months, as is the current practice in the USA. The need for a late booster dose may limit the value of this vaccine in developing countries where vaccination of children is difficult after the 1st year of life.

Antibodies, Bacterial↗
PubMed1993

MHC class II-restricted presentation of endogenously synthesized antigen: Epstein-Barr virus transformed B cell lines can present the viral glycoprotein gp340 by two distinct pathways.

Epstein-Barr virus (EBV) transformed B lymphoblastoid cell lines (LCL) efficiently process exogenous antigens for MHC class II-restricted presentation via the chloroquine-sensitive endosomal pathway. Using MHC class II-restricted T cell clones specific for EBV structural proteins, however, we frequently observed significant responses to autologous LCL cells without the addition of exogenous virus. Such responses were reduced by pre-treating the LCL with acyclovir (ACV), a drug blocking productive EBV infection. This suggested T cell recognition of antigen synthesized by LCL cells spontaneously entering virus productive cycle, and led us to question by what route(s) MHC class II-restricted presentation of endogenously synthesized virion proteins was occurring. Cell sorting experiments, using the viral envelope glycoprotein gp340 as a surface marker of productively-infected cells, confirmed that stimulatory activity lay within the gp340-positive fraction. However, closer analysis revealed that most of these cells were not productively-infected but were EBV receptor-positive and had bound released virus. We infer that receptor-mediated delivery of released virus into the endosomal pathway is one route whereby an LCL can present endogenously synthesized EBV proteins on MHC class II molecules. To ask whether another, more direct, route of processing was possible, we used a recombinant vaccinia viral vector to express gp340 de novo in ACV-treated LCLs. Significantly, these cells presented the endogenously synthesized antigen to autologous gp340-specific T cell clones via a chloroquine-resistant pathway. In the same experiments, vaccinia-mediated expression of a signal peptide-deleted form of gp340 did not lead to T cell stimulation, suggesting that this second route of processing required entry of endogenously synthesized antigen into the endoplasmic reticulum.

Amino Acid Sequence↗
PubMed1993

HLA A2.1-restricted cytotoxic T cells recognizing a range of Epstein-Barr virus isolates through a defined epitope in latent membrane protein LMP2.

Cytotoxic T-lymphocyte (CTL) responses induced by persistent Epstein-Barr virus (EBV) infection in normal B-lymphoid tissues could potentially be directed against EBV-positive malignancies if expression of the relevant viral target proteins is maintained in tumor cells. For malignancies such as nasopharyngeal carcinoma and Hodgkin's disease, this will require CTL targeting against the nuclear antigen EBNA1 or the latent membrane proteins LMP1 and LMP2. Here we analyze in detail a B95.8 EBV-reactivated CTL response which is specific for LMP2 and restricted through a common HLA allele, A2.1. We found that in vitro-reactivated CTL preparations from several A2.1-positive virus-immune donors contained detectable reactivity against A2.1-bearing target cells expressing either LMP2A or the smaller LMP2B protein from recombinant vaccinia virus vectors. Peptide sensitization experiments then mapped the A2.1-restricted response to a single epitope, the nonamer CLGGLLTMV (LMP2A residues 426 to 434), whose sequence accords well with the proposed peptide binding motif for A2.1. Most Caucasian and African virus isolates (whether of type 1 or type 2) were identical in sequence to B95.8 across this LMP2 epitope region, although 2 of 12 such isolates encoded a Leu-->Ile change at epitope position 6. In contrast, most Southeast Asian and New Guinean isolates (whether of type 1 or type 2) constituted a different virus group with a Cys-->Ser mutation at epitope position 1. CTLs raised against the B95.8-encoded epitope were nevertheless able to recognize these variant epitope sequences in the context of A2.1 whether they were provided exogenously as synthetic peptides or generated endogenously in B cells transformed with the variant viruses. A CTL response of this kind could have therapeutic potential in that it is directed against a protein expressed in many EBV-positive malignancies, is reactive across a range of virus isolates, and is restricted through a relatively common HLA allele.

Amino Acid Sequence↗
PubMed1993

Cytogenetic rearrangement of C-MYC oncogene occurs prior to infection with Epstein-Barr virus in the monoclonal malignant B cells from an AIDS patient.

Two cell lines were originated from the peripheral blood (PB-LAM) and bone-marrow (BM-LAM) of a patient with Burkitt-type acute lymphoblastic leukemia and AIDS. 26 and 7 clones were isolated from PB-LAM and BM-LAM respectively by limiting dilution. All of these had surface IgM lambda and the CD10 marker with low to absent CD23, CD30, CD39 and surface adhesion molecules. Furthermore, they shared the same chromosomal abnormalities (trisomy 7 and t(8;14) translocation) and the same rearrangements of immunoglobulin L and H chain and of c-myc gene loci. These features are those most frequently found in Burkitt's lymphoma (BL) cells and were different from those of the parental cell lines, which, besides cells identical to those of the malignant clones, also contained normal lymphoblastoid cells. Therefore, the cloning procedure used selected for the growth of cells with malignant features. EBV latent antigens were detected in all clones by Western blotting and their pattern of expression resembled that usually observed in BL cells. All the clones were positive for the EBV genome by Southern blotting and had monomorphic EBV-fused termini as determined by using cDNA probes specific for sequences at either end of the viral genome. However, the clones derived from PB-LAM had EBV fused termini of a different size from that of the clones derived from BM-LAM. The presence of different EBV-fused termini in otherwise monoclonal malignant cells indicate that EBV infection was possibly a late event in lymphomagenesis following rearrangement of the c-myc and the Ig gene loci.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Epstein-Barr virus and the lacrimal gland pathology of Sjögren's syndrome.

The lacrimal gland (LG) immunopathology of Sjögren's syndrome (SS) consists of a proliferation of B and CD4 lymphocytes surrounding epithelial structures (Pepose JS, et al: Ophthalmology 1990, 97:1599-1605). Based on the detection of EBV genomes in a greater percentage of SS than normal LG biopsies, we previously postulated that Epstein-Barr virus (EBV) is a risk factor for LG lymphoproliferation in SS (Pflugfelder SC, et al: Ophthalmology 1990, 97:976-984). The purpose of this study was to determine the cellular site(s) of infection, virus type, and antigen expression of EBV infecting normal and SS LGs. EBV DNA was detected by in situ hybridization in intraductal epithelia in 13-33% of lobules in 21% of normal LGs and in cells in areas of B lymphoproliferation as well as the majority of epithelia in 86% of SS LGs. EBV genomic sequences were amplified from 36% of normal and 88% of SS LG biopsies by polymerase chain reaction. Only type 1 EBV sequences were amplified in SS LGs; in contrast EBV nuclear antigen 2-deleted but not type 1 sequences were amplified in normal LGs. Immunohistochemistry with EBV-specific monoclonal antibodies was performed on normal and SS LGs. No EBV antigens were detected in normal LGs. In contrast, latent antigens (latent membrane protein, EBV nuclear antigen 2) were detected in lymphocytes in areas of B lymphoproliferation, and early and late lytic cycle antigens were observed in epithelia in SS LGs. These studies suggest that EBV may play a role in the LG B lymphoproliferation and epithelial pathologic changes observed in SS.

Adult↗
PubMed1992

Identification of target antigens for the human cytotoxic T cell response to Epstein-Barr virus (EBV): implications for the immune control of EBV-positive malignancies.

Epstein-Barr virus (EBV), a human herpes virus with oncogenic potential, persists in B lymphoid tissues and is controlled by virus-specific cytotoxic T lymphocyte (CTL) surveillance. On reactivation in vitro, these CTLs recognize EBV-transformed lymphoblastoid cell lines (LCLs) in an HLA class I antigen-restricted fashion, but the viral antigens providing target epitopes for such recognition remain largely undefined. Here we have tested EBV-induced polyclonal CTL preparations from 16 virus-immune donors on appropriate fibroblast targets in which the eight EBV latent proteins normally found in LCLs (Epstein-Barr nuclear antigen [EBNA] 1, 2, 3A, 3B, 3C, leader protein [LP], and latent membrane protein [LMP] 1 and 2) have been expressed individually from recombinant vaccinia virus vectors. Most donors gave multicomponent responses with two or more separate reactivities against different viral antigens. Although precise target antigen choice was clearly influenced by the donor's HLA class I type, a subset of latent proteins, namely EBNA 3A, 3B, and 3C, provided the dominant targets on a range of HLA backgrounds; thus, 15 of 16 donors gave CTL responses that contained reactivities to one or more proteins of this subset. Examples of responses to other latent proteins, namely LMP 2 and EBNA 2, were detected through specific HLA determinants, but we did not observe reactivities to EBNA 1, EBNA LP, or LMP 1. The bulk polyclonal CTL response in one donor, and components of that response in others, did not map to any of the known latent proteins, suggesting that other viral target antigens remain to be identified. This work has important implications for CTL control over EBV-positive malignancies where virus gene expression is often limited to specific subsets of latent proteins.

Antigens, Viral↗
PubMed1992

Epstein-Barr viral DNA in acute large granular lymphocyte (natural killer) leukemic cells.

Serologic studies in a male Caucasian presenting with an acute hepatitis-like illness, associated with an increase in peripheral blood large granular lymphocytes (LGLs), suggested a chronic or reactived Epstein-Barr virus (EBV) infection. The LGL were shown to have a natural killer (NK) cell, CD3- CD16- CD56+ CD57- phenotype and mediated strong nonspecific major histocompatability complex-unrestricted (NK) cytotoxic activity. A progressive increase in the peripheral blood LGL count was associated with a rapid deterioration, hepatic necrosis, and death. Widespread organ infiltration with LGLs suggested a malignant lymphoproliferative condition, but no lymphoid (T-cell receptor or IgH) gene rearrangement or cytogenetic marker was detected. However, molecular analysis identified EBV genomic DNA present in a single episomal form within the LGL, establishing the clonal nature of the LGL proliferation. Confirmation that the EBV had infected the leukemic LGL was obtained by in situ hybridization studies that showed EBV RNA within the LGLs. Immunoblotting of LGL protein extracts established that, of the EBV gene products, EBV nuclear antigen-1 (EBNA-1) was expressed but EBNA-2 and the latent membrane protein (LMP-1) were not detectable in the leukemic cells. These results suggest that EBV may be involved directly in LGL cell transformation, in a manner similar to EBV-associated B-cell lymphomas, although other molecular changes probably contribute to the evolution of a fully malignant leukemic clone.

Antigens, CD↗
PubMed1992

Restoration of the LFA-3 adhesion pathway in Burkitt's lymphoma cells using an LFA-3 recombinant vaccinia virus: consequences for T cell recognition.

Conjugate formation between cytotoxic T lymphocytes (CTL) and target B cells, as observed in vitro, is mediated by interactions between adhesion molecules on the two cell surfaces rather than involving immune recognition through the T cell receptor. It is still not clear to what extent such adhesive contacts facilitate the process of immune recognition and target cell lysis. However, work on the Epstein-Barr virus (EBV)-associated malignancy Burkitt's lymphoma (BL) has suggested that down-regulation of one particular adhesion molecule, the lymphocyte function-associated antigen LFA-3, on the tumor cell surface is a key factor in allowing these target cells to escape EBV-specific T cell surveillance. To examine this directly, we used a cDNA for the full-length transmembrane form of LFA-3 to construct a recombinant vaccinia virus (Vacc-LFA 3), which is capable of restoring surface LFA-3 in adhesion molecule-negative BL cell lines to levels as high as seen in EBV-transformed lymphoblastoid cell lines (LCL); biochemical studies confirmed expression of the authentic N-glycosylated protein. The recombinant vaccinia-encoded LFA-3 was functional as an adhesion molecule since BL cells acutely infected with Vacc-LFA-3 then acquired the ability to form conjugates with activated T cells in vitro. However, there was no clear dependence upon LFA-3 when such BL cell lines were tested as targets for cytotoxic T lymphocytes (CTL). Firstly, LFA-3- BL cells could be killed by allospecific CTL recognizing HLA class I alloantigens, in some cases as efficiently as the corresponding LCL. In other cases where lysis was slightly below that of the LCL, Vacc-LFA-3 infection of the BL cells increased lysis up to, but never beyond, LCL values. Secondly, we studied the sensitivity of BL to EBV-specific HLA class I-restricted CTL using a BL target line which was LFA-3- but which expressed the same spectrum of EBV target proteins as an LCL. This line was not recognized by appropriately HLA-matched effectors, even after restoration of LFA-3 expression. We conclude that the LFA-3 status of BL cells influences their conjugate forming ability in in vitro assays but not necessarily their sensitivity to immune T cell-mediated cytolysis.

Antigens, Surface↗
PubMed1992

Immunohistochemical demonstration of the Epstein-Barr virus-encoded latent membrane protein in paraffin sections of Hodgkin's disease.

Paraffin sections from 46 cases of Hodgkin's disease were examined for the presence of the Epstein-Barr virus (EBV)-encoded latent membrane protein (LMP) using a sensitive (double layer alkaline phosphatase-anti-alkaline phosphatase) immunohistochemical method. LMP was detected in 22 cases, the majority of positive cases being of nodular sclerosis (12/24), mixed cellularity (6/7), and lymphocyte depletion (3/3) subtypes. Only one of 12 cases of lymphocyte predominant disease was positive. In all cases, reactivity was confined to Hodgkin's and Reed-Sternberg cells. These results provide further evidence for an association between EBV and Hodgkin's disease and indicate that LMP may be readily detected in archival material.

Herpesvirus 4, Human↗
PubMed1992

Three transcriptionally distinct forms of Epstein-Barr virus latency in somatic cell hybrids: cell phenotype dependence of virus promoter usage.

Phenotypically distinct human B cell lines display two transcriptionally distinct forms of Epstein-Barr virus (EBV) latency. Latency I (Lat I) in group I Burkitt's lymphoma (BL) cell lines is characterized by selective expression of the virus-coded nuclear antigen EBNA 1 from a uniquely spliced mRNA driven by the Fp promoter. Latency III (Lat III) in group III BL and EBV-transformed lymphoblastoid cell lines (LCLs) is characterized by expression of EBNAs 1, 2, 3a, 3b, 3c, and -LP from mRNAs driven by the Cp or Wp promoter and of the latent membrane proteins (LMPs 1, 2A, and 2B) from mRNAs driven by the LMP promoters. Here we have altered the group I BL and LCL phenotypes by cell hybridization and screened for attendant changes in EBV latency by PCR analysis of viral mRNAs and immunoblotting of viral proteins. Fusion of group I BL cells with LCLs activated the BL virus genome from a Lat I to Lat III pattern of gene expression. Fusion of LCLs with nonlymphoid lines repressed virus gene expression from Lat III either to Lat I or to another form of latency (Lat II) hitherto not seen in vitro and characterized by selective expression of the Fp-driven EBNA 1 mRNA and of the LMP 1, 2A, and 2B transcripts. There are therefore three forms of EBV latency which can be interconverted by altering cellular phenotype and thereby virus promoter usage.

Antigens, Viral↗
PubMed1992

Three pathways of Epstein-Barr virus gene activation from EBNA1-positive latency in B lymphocytes.

Previous studies on Epstein-Barr virus (EBV)-positive B-cell lines have identified two distinct forms of virus latency. Lymphoblastoid cell lines generated by virus-induced transformation of normal B cells in vitro, express the full spectrum of six EBNAs and three latent membrane proteins (LMP1, LMP2A, and LMP2B); furthermore, these lines often contain a small fraction of cells spontaneously entering the lytic cycle. In contrast, Burkitt's lymphoma-derived cell lines retaining the tumor biopsy cell phenotype express only one of the latent proteins, the nuclear antigen EBNA1; such cells do not enter the lytic cycle spontaneously but may be induced to do so by treatment with such agents as tetradecanoyl phorbol acetate and anti-immunoglobulin. The present study set out to determine whether activation of full virus latent-gene expression was a necessary accompaniment to induction of the lytic cycle in Burkitt's lymphoma lines. Detailed analysis of Burkitt's lymphoma lines responding to anti-immunoglobulin treatment revealed three response pathways of EBV gene activation from EBNA1-positive latency. A first, rapid response pathway involves direct entry of cells into the lytic cycle without broadening of the pattern of latent gene expression; thereafter, the three "latent" LMPs are expressed as early lytic cycle antigens. A second, delayed response pathway in another cell subpopulation involves the activation of full latent gene expression and conversion to a lymphoblastoidlike cell phenotype. A third response pathway in yet another subpopulation involves the selective activation of LMPs, with no induction of the lytic cycle and with EBNA expression still restricted to EBNA1; this type of latent infection in B lymphocytes has hitherto not been described. Interestingly, the EBNA1+ LMP+ cells displayed some but not all of the phenotypic changes normally induced by LMP1 expression in a B-cell environment. These studies highlight the existence of four different types of EBV infection in B cells, including three distinct forms of latency, which we now term latency I, latency II, and latency III.

Antigens, Viral↗
PubMed1992

The Epstein-Barr virus (EBV) nuclear antigen 1 BamHI F promoter is activated on entry of EBV-transformed B cells into the lytic cycle.

In Epstein-Barr virus (EBV)-positive Burkitt's lymphoma cell lines exhibiting the latency I form of infection (i.e., EBV nuclear antigen 1 [EBNA1] positive in the absence of other latent proteins), the EBNA1 mRNA has a unique BamHI Q/U/K splice structure and is expressed from a novel promoter, Fp, located near the BamHI FQ boundary. This contrasts with the situation in EBV-transformed lymphoblastoid cell lines (LCLs) exhibiting the latency III form of infection (i.e., positive for all latent proteins), in which transcription from the upstream Cp or Wp promoters is the principal source of EBNA mRNAs. We carried out cDNA amplifications with oligonucleotide primer-probe combinations to determine whether Fp is ever active in an LCL environment. The results clearly showed that some LCLs express a Q/U/K-spliced EBNA1 mRNA in addition to the expected Cp/Wp-initiated transcripts; this seemed inconsistent with the concept of Cp/Wp and Fp as mutually exclusive promoters. Here we show that Fp is indeed silent in latency III cells but is activated at an early stage following the switch from latency III into the virus lytic cycle. Four pieces of evidence support this conclusion: (i) examples of coincident Cp/Wp and Fp usage in LCLs are restricted to those lines in which a small subpopulation of cells have spontaneously entered the lytic cycle; (ii) transcripts initiating from Fp can readily be demonstrated in spontaneously productive lines by S1 nuclease protection; (iii) the presence of Fp-initiated transcripts is not affected by acyclovir blockade of the late lytic cycle; and (iv) infection of latently infected LCLs with a recombinant vaccinia virus encoding the EBV immediate-early protein BZLF1, a transcriptional transactivator which normally initiates the lytic cycle, results in the appearance of the diagnostic Q/U/K-spliced transcripts.

Antigens, Viral↗
PubMed1992

Characterization of EBV-positive lymphoblastoid cell lines obtained from HIV seropositive patients with or without lymphomas.

Epstein-Barr-virus- (EBV-) positive lymphoblastoid cell lines (LCLs) spontaneously arising in vitro were obtained from the peripheral blood of six HIV-seropositive patients and from the peripheral blood and the bone marrow of one patient (LAM) with AIDS and lymphoma. The LCLs from HIV-seropositive patients had phenotypic, cytogenetic, and biological characteristics indistinguishable from those of normal LCLs obtained by infecting B cells with EBV in vitro. The LCLs from LAM patient comprised composite cell populations. Cloning analysis and cell fractionation procedures showed that, beside normal EBV-infected cells, these lines contained a malignant subset population characterized by c-myc rearrangement, abnormal karyotype, and a surface phenotype similar to that of Burkitt's lymphoma cells. Analyses of Ig heavy chain and c-myc oncogene loci showed that these malignant cells were the progeny of a single precursor. Nevertheless, these cells had heterogeneous EBV-fused termini, a finding which indicates that EBV infection followed c-myc rearrangement.

Blotting, Southern↗
PubMed1992

Epstein-Barr virus, lymphomas and Hodgkin's disease.

Epstein-Barr virus (EBV) is implicated in the pathogenesis of a number of human lymphoid malignancies, including the immunoblastic B lymphomas that arise in immunocompromised individuals, Burkitt's lymphoma, Hodgkin's disease, and certain T cell lymphomas. The immunoblastic lymphomas are most likely a direct consequence of EBV-driven B cell lymphoproliferation that would in normal circumstances be eliminated by virus-specific cell-mediated immune responses. The other EBV-associated malignancies arise in individuals with more or less intact cellular immune responses and appear to have a complex multi-step pathogenesis. Throughout the EBV-positive lymphoid malignancies there is an intimate association between tumour cell phenotype and virus latent gene expression, with each of the three forms of latency seen in in vitro models being exemplified in vivo. Tumours with these different forms of virus latency will differ in their susceptibility to EBV-specific immune T cell control.

Cell Transformation, Neoplastic↗
PubMed1992

Epstein-Barr virus and carcinomas. Expression of the viral genome in an undifferentiated gastric carcinoma.

The Epstein-Barr virus (EBV) is associated with undifferentiated nasopharyngeal carcinomas (NPCs). Recently, EBV DNA has been demonstrated also in some cases of gastric carcinoma with similar morphology as undifferentiated NPC. Here we report on the expression of EBV genes in a gastric undifferentiated carcinoma of nasopharyngeal type (UCNT). The small EBV-encoded nuclear RNAs, EBERs, were expressed in all tumor cells. The BZLF1 transactivator protein, which disrupts viral latency, was detectable in a small subset of tumor cells. The latent membrane protein and the nuclear antigen EBNA2 were not expressed. These results indicate that lytic EBV infection may be possible in undifferentiated epithelial cells. Our findings add to the growing body of evidence suggesting a strong association of gastric UCNT with EBV and point to the possibility of an involvement of the virus in the pathogenesis of this neoplasm.

DNA, Viral↗
PubMed1991

Epstein-Barr virus DNA and latent gene products in Ki-1 (CD30)-positive anaplastic large cell lymphomas.

Epstein-Barr virus (EBV)-specific DNA sequences were detected by polymerase chain reaction analysis in 15 of 47 (32%) DNA extracts prepared from CD30-positive (Ki-1 antigen-positive) anaplastic large cell (ALC) lymphomas. EBV-encoded RNA (EBER) transcripts could be detected by in situ hybridization in the tumor cells of 9 of 11 EBV DNA-positive cases. Twenty-eight cases were examined by immunohistology on cryostat sections for the presence of the EBV-encoded latent membrane protein (LMP), the nuclear antigen 2 (EBNA2), the BZLF1 transactivator protein, and the late viral glycoprotein gp350/250. A distinct LMP-specific membrane and cytoplasmic staining was detected exclusively in lymphoma cells of five cases (18%); two of these cases additionally expressed EBNA2. BZLF1 protein and gp350/250 immunoreactivity was absent in all instances. All LMP-positive cases contained EBV DNA and EBER sequences. The pattern of EBV latent protein expression in ALC lymphomas showed heterogeneity with respect to EBNA2 expression: LMP-positive/EBNA2-negative cases displayed a pattern previously described for undifferentiated nasopharyngeal carcinomas and Hodgkin's disease, whereas LMP-positive and EBNA2-positive cases showed parallels to lymphoblastoid cell lines. Because the LMP gene has transforming potential, our findings support the concept of a pathoetiologic role for EBV in a proportion of CD30-positive ALC lymphomas.

Adult↗