Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “lytic replication”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources
PubMed2005

[Effect of replication- competent adenovirus-mediated interleukin- 12 gene to chemotherapeutic sensitivity on gastric cancer cell].

OBJECTIVE: To investigate the effect of replication-competent adenovirus-mediated interleukin-12 gene to chemotherapeutic sensitivity on gastric cancer cell. METHODS: Replication-competent adenovirus and replication-competent adenovirus- mediated interleukin- 12 gene was constructed and expanded separately. The mortality of gastric cancer cell caused by the CNHK200- mIL- 12, Onyx- 015 in combination with different dosages of chemotherapeutic agents were evaluated by MTT assay at the same viral titer with a series of different dosages of chemotherapeutic agent,or at a series of different viral titers with the same dosage of chemotherapeutic agent. The curative effect to the xenografts gastric tumor in nude mouse was also observed by two viruses solely or together with 5-Fu. RESULTS: The lytic activity of replication-competent adenovirus to gastric cancer cell line SGC-7901 was relatively poor at MOI value of 0.5, but it could be improved significantly when combined with chemotherapeutic agents of ADM, 5-Fu or CAP compared to the simple chemical therapy (P< 0.05). Chemotherapeutic agent 5- Fu could not effectively kill SGC-7901 when used at a relatively low dosage of 10microg/ml,whereas its activity could be improved when combined with a replication-competent adenovirus,and the killing rate was much higher than that with replication-competent adenovirus solely (P< 0.05). The gastric tumor xenografts was prevented and killed by replication adenovirus solely or combined with 5-Fu. CONCLUSION: The replication- competent adenovirus- mediated interleukin- 12 gene can increase the chemotherapeutic sensitivity on gastric cancer cell. There is synergetic effect between the replication adenovirus and the chemotherapeutic agents in killing gastric cancer cell.

Adenoviridae↗
PubMed2006

Cyclooxygenase 2 induced by Kaposi's sarcoma-associated herpesvirus early during in vitro infection of target cells plays a role in the maintenance of latent viral gene expression.

Infection of human dermal microvascular endothelial (HMVEC-d) cells and human foreskin fibroblast (HFF) cells in vitro by Kaposi's sarcoma-associated herpesvirus (KSHV) provides an excellent in vitro model system to study viral latency. KSHV infection is characterized by the induction of preexisting host signal cascades; sustained expression of the latency-associated open reading frame 73 (ORF73) (LANA-1), ORF72, and K13 genes; transient expression of a limited number of lytic genes, including the lytic cycle switch ORF50 (replication and transcription activator) gene; and reprogramming of host transcriptional machinery regulating a variety of cellular processes, including several proinflammatory responses. The cyclooxygenase 2 (COX-2) gene was one of the host cell genes that was highly up-regulated at 2 and 4 h postinfection (p.i.) of HMVEC-d and HFF cells (P. P. Naranatt, H. H. Krishnan, S. R. Svojanovsky, C. Bloomer, S. Mathur, and B. Chandran, Cancer Res. 64:72-84, 2004). Since COX-2 is an important mediator of inflammatory and angiogenic responses, here, using real-time PCR, Western blot, and immunofluorescence assays, we characterized the COX-2 stimulation and its role in KSHV infection. KSHV induced a robust COX-2 expression, which reached a maximum at 2 h p.i. in HMVEC-d cells and at 8 h p.i. in HFF cells, and significantly higher levels were continuously detected for up to 72 h p.i. Constitutive COX-1 protein levels were not modulated by KSHV infection. Moderate levels of COX-2 were also induced by UV-irradiated KSHV and by envelope glycoproteins gB and gpK8.1A; however, viral gene expression appears to be essential for the increased COX-2 induction. High levels of prostaglandin E(2) (PGE(2)), a COX-2 product, were released in the culture supernatant medium of infected cells. PGE(2) synthase, catalyzing the biosynthesis of PGE(2), also increased upon infection and inhibition of COX-2 by NS-398, and indomethacin drastically reduced the levels of PGE(2) and PGE(2) synthase. COX-2 inhibition did not affect KSHV binding, internalization of virus, or the trafficking to the infected cell nuclei. However, latent ORF73 gene expression and ORF73 promoter activity were significantly reduced by COX-2 inhibitors, and this inhibition was relieved by exogenous supplementation with PGE(2). In contrast, lytic ORF50 gene expression and ORF50 promoter activity were unaffected. These studies demonstrate that COX-2 and PGE(2) play roles in facilitating latent viral gene expression and the establishment and maintenance of latency and suggest that KSHV has evolved to utilize the inflammatory responses induced during infection of endothelial cells for the maintenance of viral latent gene expression.

Cell Line↗
PubMed1975

Detection of virus-specific DNA sequences by quantitative in situ hybridization during infection with SV40.

In situ hybridization has been used as a quantitative method to study the replication of SV40 during lytic infection. Various parameters have been defined such as fixation and denaturation of cytological preparations, concentration of complementary (3H)-cRNA and volume of buffer used for the hybridization reaction. When all these parameters are carefully controlled, a reproducibility of +/-10% can be obtained for the quantitative study of the system SV40-monkey kidney cells (CV-1). In this system, it is evident that the synthesis of viral DNA is not synchronized in confluent cells. Moreover, a proportion of 20 to 30% of cells are not labelled whatever the multiplicity of infection. In SV40-transformed cells, it was not possible to detect significantly the integrated genome due either to the small size of the genome or to the fact that the number of genome-equivalents integrated at the same place is too low to yield a radioactivitity superior to background level for long periods of exposure.

Animals↗
PubMed2000

Infection of primary human monocytes by Epstein-Barr virus.

Previous studies have reported that infection of monocytes by viruses such as cytomegalovirus and human immunodeficiency virus weakens host natural immunity. In the present study, we demonstrated the capability of Epstein-Barr virus (EBV) to infect and replicate in freshly isolated human monocytes. Using electron microscopy analysis, we observed the presence of EBV virions in the cytoplasm and nuclei of approximately 20% of monocytes. This was confirmed by Southern blot analysis of EBV genomic DNA sequences in isolated nuclei from monocytes. Infection of monocytes by EBV leads to the activation of the replicative cycle. This was supported by the detection of immediate-early lytic mRNA BZLF-1 transcripts, and by the presence of two early lytic transcripts (BALF-2, which appears to function in DNA replication, and BHRF-1, also associated with the replicative cycle). The late lytic BcLF-1 transcripts, which code for the major nucleocapsid protein, were also detected, as well as EBNA-1 transcripts. However, attempts to detect EBNA-2 transcripts have yielded negative results. Viral replication was also confirmed by the release of newly synthesized infectious viral particles in supernatants of EBV-infected monocytes. EBV-infected monocytes were found to have significantly reduced phagocytic activity, as evaluated by the quantification of ingested carboxylated fluoresceinated latex beads. Taken together, our results suggest that EBV infection of monocytes and alteration of their biological functions might represent a new mechanism to disrupt the immune response and promote viral propagation during the early stages of infection.

Cell Nucleus↗
PubMed1981

Virus infection of endothelial cells.

Endothelial injury is important in the pathogenesis of thrombosis, atherosclerosis, disseminated intravascular coagulation, and vasculitis. The ability of several common human viruses to infect cultures of endothelial cells obtained from human umbilical veins or bovine thoracic aorta was demonstrated. Indicators of infection included cytopathology, viral growth curves, and antigen detection by immunofluorescence. Herpes simplex virus type 1, adenovirus type 7, measles virus, and parainfluenza virus type 3 infected both human venous and bovine aorta endothelium. Mumps virus, poliovirus type 1, and echovirus type 9 grew only in human venous cells; coxsackievirus B4 infected only bovine arterial cultures; and cytomegalovirus, influenza A/Victoria/75 (H3N2) virus, and respiratory syncytial virus failed to grow in either cell culture. During replication some viruses caused acute lytic changes; some produced chronic, less destructive alterations; and other induced no apparent cytopathology. The results suggest that viral replication within endothelium may be important in the pathogenesis of viral disease of initiation of vessel-wall injury.

Adenoviruses, Human↗
PubMed1994

Papillomavirus contains cis-acting sequences that can suppress but not regulate origins of DNA replication.

Bovine papillomavirus (BPV) DNA has been reported to restrict its own replication and that of the lytic simian virus 40 (SV40) origin to one initiation event per molecule per S phase, which suggests BPV DNA replication as a model for cellular chromosome replication. Suppression of the SV40 origin required two cis-acting BPV sequences (NCOR-1 and -2) and one trans-acting BPV protein. The results presented in this paper confirm the presence of two NCOR sequences in the BPV genome that can suppress polyomavirus (PyV) as well as SV40 origin-dependent DNA replication as much as 40-fold. However, in contrast to results of previous studies on SV40, most of the suppression of the PyV origin was due to NCOR-1, a 512-bp sequence that functioned independently of distance or orientation with respect to the PyV origin and that was not required for BPV DNA replication. Moreover, NCOR-1 alone or together with NCOR-2 did not restrict the ability of the PyV ori to reinitiate replication within a single S phase and did not require any BPV protein to exert suppression. Furthermore, NCOR-1 did not suppress BPV origin-dependent DNA replication except in the presence of PyV large tumor antigen (T-ag). Since NCOR-1 suppression of PyV origin activity also varied with T-ag concentration, suppression of origins by NCOR sequences appeared to require papovavirus T-ag. Therefore, it is unlikely that NCOR sequences are involved in regulating BPV DNA replication. When these results are taken together with those from other laboratories, BPV appears to be a slowly replicating version of papovaviruses rather than a model for origins of DNA replication in eukaryotic cell chromosomes.

Antigens, Viral, Tumor↗
PubMedDate not supplied

Human herpesvirus-8-encoded signalling ligands and receptors.

Analysis of the genome of human herpesvirus 8 (HHV-8) led to the discovery of several novel genes, unique among the characterized gammaherpesviruses. These include cytokines (interleukin-6 and chemokine homologues), two putative signal-transducing transmembrane proteins encoded by genes K1 and K15 at the genome termini, and an OX-2 (CD200) receptor homologue that had not previously been identified in a gammaherpesvirus. HHV-8 also specifies a diverged version of the gammaherpesvirus-conserved G protein-coupled chemokine receptor (vGCR) and a latently expressed protein unique to HHV-8 specified by open reading frame (ORF) K12. These cytokine and receptor homologues mediate signal transduction or modulate the activities of other endogenous cytokines and receptors to enhance viral productive replication, regulate latent-lytic switching, evade host attack, or mediate cell survival. The viral signalling ligands and receptors are also potential contributors to virus-associated diseases, Kaposi's sarcoma, primary effusion lymphoma, and multicentric Castleman's disease, and so represent potentially important targets for therapeutic and antiviral drugs. Understanding these proteins' modes of action and functions in viral biology and disease is therefore of considerable importance, and the subject of this review.

Castleman Disease↗
PubMed2002

Quantitation of the spliced late gene of human cytomegalovirus and its kinetics during experimental infection.

Human cytomegalovirus (hCMV) infection is still a cause of morbidity and mortality after solid organ and bone marrow transplantation and in other immunocompromised states. 'Preemptive therapy' strategies necessitate sensitive and specific methods for rapid diagnosis of symptomatic hCMV infection and monitoring of antiviral treatment. For analysis of the lytic stage of viral replication, the molecular determination of late transcripts is a useful approach for diagnosis of hCMV disease. In the present study we established an absolute quantitation of hCMV spliced late gene (SLG) RNA transcripts by real-time reverse transcription-polymerase chain reaction. Intron spanning primers were used for amplification to discriminate between viral DNA and cDNA. For standardization of the varying amounts of cDNA analyzed, cytoplasmic beta2-microglobulin (beta2-MG) cDNA was quantitated in parallel. cDNA copy numbers of both target sequences could be quantitated in a wide linear range from 10 to 10(7) copies. To investigate the applicability of the developed assay, diploid lung fibroblasts were infected with the virus strain AD169. SLG expression was measured during a 48-h period after inoculation. After an only low expression during the first 10 h (approximately 5 x 10(2) copies/sample or SLG/beta2-MG ratio <0.001), SLG transcription increased dramatically after 24 h, peaking at 5x104 copies/sample or SLG/beta2-MG ratio of 0.035 after 48 h. Intra- and interassay variability was less than 5% for calibrators and less than 10% samples. We conclude that quantitation of SLG transcripts by the presented method might be a powerful tool for differentiating between hCMV latency and active replication in vitro end in vivo, and thus may be a promising tool for diagnosis of symptomatic hCMV infection and monitoring of antiviral treatment.

Calibration↗
PubMed2004

The Epstein-Barr virus polymerase accessory factor BMRF1 adopts a ring-shaped structure as visualized by electron microscopy.

Epstein-Barr virus (EBV) encodes a set of core replication factors used during lytic infection in human cells that parallels the factors used in many other systems. These include a DNA polymerase and its accessory factor, a helicase/primase, and a single strand binding protein. The EBV polymerase accessory factor has been identified as the product of the BMRF1 gene and has been shown by functional assays to increase the activity and processivity of the polymerase. Unlike other members of this class of factors, BMRF1 is also a transcription factor regulating certain EBV genes. Although several polymerase accessory factors, including eukaryotic proliferating cell nuclear antigen, Escherichia coli beta protein, and T4 gene 45 protein have been shown to form oligomeric rings termed sliding clamps, nothing is known about the oligomeric state of BMRF1 or whether it forms a ring. In this work, BMRF1 was purified directly from human cells infected with an adenovirus vector expressing the BMRF1 gene product. The protein was purified to near homogeneity, and examination by negative staining electron microscopy revealed large, flat, ring-shaped molecules with a diameter of 15.5 +/- 0.8 nm and a distinct 5.3-nm diameter hole in the center. The size of these rings is consistent with an oligomer of 6 monomers, nearly twice as large as the trimeric proliferating cell nuclear antigen ring. Unlike the herpes simplex virus UL42 homologue, BMRF1 was found to self-associate in solution. These findings extend the theme of polymerase accessory factors adopting ring-shaped structures and provide an example in which the ring is significantly larger than any previously described sliding clamp.

Adenoviridae↗
PubMed1993

Viral interleukin 10 is critical for the induction of B cell growth transformation by Epstein-Barr virus.

We have used an efficient cDNA subtraction library procedure to identify newly induced genes in human B lymphocytes infected for 6 h with Epstein-Barr virus (EBV). Among the genes identified by automated sequencing of a random subset of clones from this library, one coded the EBV BCRF1 open reading frame, which specifies the viral interleukin 10 gene (vIL-10). This molecule is highly homologous to human (h)IL-10 and was previously thought to represent a "late" viral gene expressed only during the lytic phase of virus replication. Using gene amplification by reverse transcriptase polymerase chain reaction of B cell RNA obtained at varying times after infection, we detected vIL-10 expression within a few hours of EBV infection, followed, 20-30 h later by expression of hIL-10. Expression of both genes continued beyond the initial transformation phase (5-10 d) and was present in all transformed cell lines tested. When added at the time of viral infection, antisense (but not sense) oligonucleotides for vIL-10 mRNA (cytosolic half-life, approximately 6 h) prevented subsequent B cell transformation. The antisense effect was highly specific, leaving the expression levels of other transformation-related genes intact. Addition of exogenous (h)IL-10 rescued the transformation process in antisense-treated cells. Our observations establish vIL-10 as a new latency gene with a directly transformation-prerequisite function.

B-Lymphocytes↗
PubMed2001

Human herpesvirus-8 genes are expressed in pulmonary inflammatory myofibroblastic tumor (inflammatory pseudotumor).

The presence of human herpesvirus-8 DNA sequences, as well as an overexpression of human interleukin-6 and human cyclin D1 in myofibroblastic cells of inflammatory myofibroblastic tumor (inflammatory pseudotumor), has recently been reported. We describe the pattern of human herpesvirus-8 gene expression in five cases of pulmonary inflammatory myofibroblastic tumor. Reverse transcriptase-polymerase chain reaction (RT-PCR), with several positive and negative controls, was performed to detect mRNA of 11 open reading frames encoded by human herpesvirus-8 in lytic and latent stages of viral replicative cycle. We found molecular transcripts from ORF16, ORFK13, and ORF72 in the five cases and from ORFK2 in four of five neoplasms. The corresponding encoded proteins were human homologous oncoproteins (viral cyclin-D), inflammatory cytokines (viral IL-6), and inhibitors of apoptotic pathways (viral FLIP and viral Bcl-2), mostly expressed in a latent viral replicative stage. The rest of open reading frames examined included mainly lytic-associated genes and showed no expression. The spectrum of expressed viral genes is not the same as can be observed in Kaposi's sarcoma or multicentric Castleman's disease, suggesting that human herpesvirus-8 plays a different role in the pathogenesis of its associated diseases. These differences may be related to either cell-specific or immunologic host factors.

Activin Receptors↗
PubMed1991

The Epstein-Barr virus nuclear protein encoded by the leader of the EBNA RNAs is important in B-lymphocyte transformation.

These experiments evaluate the role of the Epstein-Barr virus (EBV) nuclear antigen leader protein (EBNA-LP) in B-lymphocyte growth transformation by using a recombinant EBV molecular genetic approach. Recombinant viruses encoding for a mutant EBNA-LP lacking the carboxy-terminal 45 amino acids were markedly impaired in their ability to transform primary B lymphocytes compared with EBNA-LP wild-type but otherwise isogenic recombinant viruses. This impairment was particularly evident when primary B lymphocytes were infected under conditions of limiting virus dilution. The impairment could be partially corrected by growth of the infected lymphocytes with fibroblast feeder layers or by cocultivation of primary B lymphocytes with relatively highly permissive mutant virus-infected cells. One of the five mutant recombinants recovered by growth of infected cells on fibroblast feeder cultures was a partial revertant which had a normal transforming phenotype. Several lymphoblastoid cell lines infected with the EBNA-LP mutant recombinant viruses had a high percentage of cells with bright cytoplasmic immunoglobulin staining, as is characteristic of cells undergoing plasmacytoid differentiation. Expression of the other EBV latent or lytic proteins and viral replication were not affected by the EBNA-LP mutations. Thus, the EBNA-LP mutant phenotype is not mediated by an effect on expression of another EBV gene. These data are most compatible with the hypothesis that EBNA-LP affects expression of a B-lymphocyte gene which is a mediator of cell growth or differentiation.

Antigens, Surface↗
PubMed2003

Structural analysis of the Kaposi's sarcoma-associated herpesvirus K1 protein.

The K1 protein of Kaposi's sarcoma-associated herpesvirus (KSHV) efficiently transduces extracellular signals to elicit cellular activation events through its cytoplasmic immunoreceptor tyrosine-based activation motif (ITAM). In addition, the extracellular domain of K1 demonstrates regional homology with the immunoglobulin (Ig) family and contains conserved regions (C1 and C2) and variable regions (V1 and V2). To generate mouse monoclonal antibodies directed against the KSHV K1 protein, BALB/c mice were primed and given boosters with K1 protein purified from mammalian cells. Twenty-eight hybridomas were tested for reactivity with K1 protein by enzyme-linked immunosorbent assay, immunofluorescence, flow cytometry, immunohistochemistry, and immunoblotting. Deletion mutants of the K1 extracellular domain were used to map the epitope of each antibody. All antibodies were directed to the Ig, C1, and C2 regions of K1. Furthermore, antibody recognition of a short sequence (amino acids 92 to 125) of the C2 region overlapping with the Ig region of K1 efficiently induced intracellular free calcium mobilization; antibody recognition of the other regions of K1 did not. The efficient signal transduction of K1 induced by antibody stimulation required both the ITAM sequence of the cytoplasmic domain and the normal structure of the extracellular domain. Finally, immunological assays showed that K1 was expressed during the early lytic cycle of viral replication in primary effusion lymphoma cells. K1 was readily detected in multicentric Castleman's disease tissues, whereas it was not detected in Kaposi's sarcoma lesions, suggesting that K1 is preferentially expressed in lymphoid cells. Thus, these results indicate that the conserved regions, particularly the Ig and C2 regions, of the K1 extracellular domain are exposed on the outer surface and play an important role in K1 structure and signal transduction, whereas the variable regions of K1 appear to be away from the surface.

Amino Acid Sequence↗
PubMed2004

Fatty acid synthase expression is induced by the Epstein-Barr virus immediate-early protein BRLF1 and is required for lytic viral gene expression.

The Epstein-Barr virus (EBV) immediate-early (IE) protein BRLF1 (R) is a transcription factor that induces the lytic form of EBV infection. R activates certain early viral promoters through a direct binding mechanism but induces transcription of the other EBV IE gene, BZLF1 (Z), indirectly through cellular factors binding to a CRE motif in the Z promoter (Zp). Here we demonstrate that R activates expression of the fatty acid synthase (FAS) cellular gene through a p38 stress mitogen-activated protein kinase-dependent mechanism. B-cell receptor engagement of Akata cells also increases FAS expression. The FAS gene product is required for de novo synthesis of the palmitate fatty acid, and high-level FAS expression is normally limited to liver, brain, lung, and adipose tissue. We show that human epithelial tongue cells lytically infected with EBV (from oral hairy leukoplakia lesions) express much more FAS than uninfected cells. Two specific FAS inhibitors, cerulenin and C75, prevent R activation of IE (Z) and early (BMRF1) lytic EBV proteins in Jijoye cells. In addition, cerulenin and C75 dramatically attenuate IE and early lytic gene expression after B-cell receptor engagement in Akata cells and constitutive lytic viral gene expression in EBV-positive AGS cells. However, FAS inhibitors do not reduce lytic viral gene expression induced by a vector in which the Z gene product is driven by a strong heterologous promoter. In addition, FAS inhibitors do not reduce R activation of a naked DNA reporter gene construct driven by the Z promoter (Zp). These results suggest that cellular FAS activity is important for induction of Z transcription from the intact latent EBV genome, perhaps reflecting the involvement of lipid-derived signaling pathways or palmitoylated proteins. Furthermore, using FAS inhibitors may be a completely novel approach for blocking the lytic form of EBV replication.

Cell Line↗
PubMed1985

Cloning of the A gene of bacteriophage Mu and purification of its product, the Mu transposase.

The bacteriophage Mu transposase (the Mu A gene product), which is absolutely required for both integration of Mu and replicative transposition during the lytic cycle, has been overproduced by cloning the gene on a plasmid under the control of the phage lambda PL promoter. The protein has been purified to near homogeneity from the lysate of heat-induced cells of a strain carrying the plasmid. The purified protein is active as judged by its ability to complement Mu A- cell extracts for supporting Mu transposition in a cell-free reaction.

Bacteriophage lambda↗
PubMed1978

Stimulated production of interferon by a low-molecular-weight factor from chicken-egg fluids.

Exposure of five-year-old L-929 cell monolayers to low-molecular-weight factor obtaiend from chicken egg-yolk fluids stimulated the production of Semliki Forest virus (SFV)-induced interferon, particularly when the cells were infected with a low-input multiplicity of SFV. The stimulatory effect on interferon production was not expressed in polyriboinosinic acid:polycytidylic acid-induced interferon. Furthermore, the high yield of interferon was correlated with and followed the increase in viral yield, thus suggesting that the yolk factor stimulates the growth of SFV, which in turn triggers the higher production of interferon. The outstanding feature of the yolk factor is its ability to stimulate the production of virus-induced interferon during the lytic cycle of virus replication.

Animals↗
PubMed1983

Immunoprecipitation as a tool for studying humoral immunity of natural and experimental hosts of Herpesvirus saimiri.

Herpesvirus saimiri strain 11 and attenuated H. saimiri strain 11 proteins synthesized during the lytic cycle of virus replication were used for immunoprecipitation with various sera from natural (Saimiri sciureus) and experimental (Saguinus nigricollis, Saguinus fuscicollis, Aotus trivirgatus, New Zealand White rabbits) hosts. The analysis of the precipitates separated in sodium dodecyl sulfate:polyacrylamide gels revealed that in tumor-developing animals a specific set of viral polypeptides were precipitated, which were not precipitated by sera obtained from the natural host Saimiri sciureus. Using labeled proteins from H. saimiri 11 and its attenuated strain, respectively, a difference was shown after precipitation with a serum raised against infected cell proteins of H. saimiri 11.

Animals↗
PubMed1993

Assessment of the methods for the detection of Epstein-Barr virus nucleic acids and related gene products in Hodgkin's disease.

BACKGROUND: Epstein-Barr virus (EBV) is present in the pathogenic cells of a significant number of cases of Hodgkin's disease, particularly of the mixed cellularity subtype. EBV remains latent and the incidence of detection rate of the genomes and gene products varies greatly with the methods employed. EXPERIMENTAL DESIGN: From a pool of 137 cases of Hodgkin's disease previously studied by cold in situ hybridization (ISH) for the presence or absence of EBV DNA and the immunohistochemical reactivity with anti-latent membrane protein 1 antibody, we selected 24 cases (12 EBV DNA-positive, 12 EBV DNA-negative) for Southern blotting, as well as for study with nonisotopic EBER and BHLF1 oligonucleotide probes and amplification of DNA by polymerase chain reaction. EBV positive cases were further tested with anti-ZEBRA (BZLF1) antibody. RESULTS: The EBV DNA detection rate was found to be lower with Southern blotting compared to ISH and IHC methods because 8 of the 12 EBV positive cases were positive with BamHI W probe and only 7 (of the 8) with XhoI 1.9 kb probe. These 7 cases contained monoclonal episomal circular EBV genomes. All EBV DNA-positive cases showed EBER gene transcription by ISH. EBER probes also reacted with small lymphocytes in all EBV DNA+ and 9 EBV DNA- cases. These EBER-positive small lymphocytes were detected neither by BamHI W DNA probe nor by immunohistochemical methods with anti-latent membrane protein 1 and anti-EBNA2 antibodies. Polymerase chain reaction produced a positive result in all EBV DNA+ cases and 2 (of the 9) EBV DNA- cases containing EBER+ small lymphocytes. This discrepancy was attributed to amplification of EBV in reactive lymphocytes. Anti-ZEBRA antibody was positive in 2 cases (one BHLF1+) suggesting infrequent viral replication and probable abortive lytic cycle. CONCLUSIONS: ISH and immunohistochemical methods are more sensitive than Southern blot for detecting EBV in Hodgkin and Reed-Sternberg cells of Hodgkin's disease. Polymerase chain reaction appears to be very sensitive but is less sensitive and specific (amplification of EBV DNA of non-neoplastic lymphocytes) than ISH with non-isotopic EBER oligoprobes, which often detects and localizes EBV in pathogenic cells even when they are in small numbers and also in a few small lymphocytes. In addition, this method offers the advantage of being applied to routinely processed tissue sections.

Antigens, Viral↗