[Immunodeficiency and carcinogenesis in patients with chronic active Epstein-Barr virus infection]

Three adult patients with chronic active Epstein-Barr virus infection (CAEBV) had high anti-EBV-VCA antibody, positive anti-EA, low anti-EBNA and were associated with systemic lymphadenopathies and immunosuppression. The case 1 and 2 had elevated serum immunoglobulin levels, and recurrent infections, and case 3 showed pancytopenia. These 3 cases developed both EBV and latent membrane protein (LMP) positive malignant histiocytosis, EBV positive but LMP negative plasmacytoma, and EBV negative acute myelogeneous leukemia, respectively. It was suggested that CAEBV belonged to high risk groups for the development of malignant neoplasms. Since HLA of the case 1 and his father was identical, we conducted a in vitro cytotoxicity test using EBV transformed autologous B lymphocytes, K562 cells, and Raji cells to clarify the association of immunosuppression and HLA. The case 1 showed a low level of specific cytotoxicity to autologous EBV transformed B cells, while his parents were negative for the specific cytotoxicity. The patient and his parents developed inducible cytotoxicity to all targets after in vitro incubation of peripheral mononuclear cells with recombinant interleukin 2 (rIL-2) for 7 days. The patient and his mother showed lower enhancement of cytotoxicity, while HLA identical father could induce good cytotoxic activity to all targets as well as normal controls, indicating that a low IL-2 induced cytotoxic activity observed in CAEBV was independent of HLA associated immunoregulation at least in the case 1. Further studies are required to clarify the exact mechanisms responsible for the development of CAEBV.

Mapping of host range restriction of the rakkyo strain of tobacco mosaic virus in Nicotiana tabacum cv. bright yellow

The rakkyo strain (TMV-R) and the common strain (TMV-U1) of tobacco mosaic virus exhibit distinct host range differences. TMV-R infects rakkyo plants, a monocot host that TMV-U1 is unable to infect. However, TMV-R causes only latent infection in Nicotiana tabacum cv. Bright Yellow (BY) in inoculated leaves, whereas TMV-U1 infects BY systemically and induces mosaic symptoms. Complete nucleotide sequencing of the TMV-R genomic RNA revealed amino acid changes in the 130K/ 180K replicase proteins, the 30K protein, and the coat protein and nucleotide changes in the 5' and 3' noncoding regions compared to TMV-U1. To identify viral components involved in determination of differences in host range, we have mapped determinants for the differential infection phenotype in BY plants by constructing chimeric viruses between the two strains in the present study. Examination of the infection phenotypes of the 14 constructed chimeric viruses in BY showed that determinants defining the differential infection phenotype in BY reside in the 130K/180K replicase proteins and the 3' noncoding region. Cognate combination of the 130K/180K replicase proteins and the 3' noncoding region of TMV-U1 origin is required to produce systemic infection in BY plants.

Oxidation products of cyanidin 3-O-beta-D-glucoside with a free radical initiator

Recently, we have reported that anthocyanins show strong antioxidative activity, but no attention has been paid to anthocyanins from the viewpoint of the reaction mechanism of alkylperoxyl radicals; therefore, we investigated the reaction products of antioxidative anthocyanins (cyanidin 3-O-beta-D-glucoside). Cyanidin 3-O-beta-D-glucoside was reacted with 2,2'-azobis(2,4-dimet hylvaleronitrile) to generate the alkylperoxyl radicals, and the reaction products were isolated by high-performance liquid chromatography. The products were identified as 4,6-dihydroxy-2-O-beta-D-glucosyl-3-oxo-2,3-dihydroben-zofuran+ ++ and protocatechuic acid. Based on reaction products, the antioxidative mechanism of cyanidin 3-O-beta-D-glucoside may be different from that of alpha-tocopherol; cyanidin 3-O-beta-D-glucoside would produce another radical scavenger, as it would break down the structure and scavenge the radicals.

Biased VH family usage in primary gastric B cell lymphoma of mucosa-associated lymphoid tissue-type and the selected V beta expression of T cells infiltrating into the lymphoma cells

Seven cases of primary gastric low-grade B cell lymphoma of mucosa-associated lymphoid tissue (MALT) type, two cases of high-grade B cell lymphoma with a low-grade component and three cases of pure high-grade lymphoma were selected for the current study. The Ig VH gene use of lymphoma cells and the V beta repertoires of infiltrating T cells were investigated. The VH gene analysis showed multiple VH family usage in 12 cases, but the MALT-type lymphoma cell usage was found to be biased for the families that have a low number of VH genes (VHIV and V). Another analysis of lymphoma-infiltrating T cells showed restricted expressions of the V beta repertoire in all seven low-grade cases and three high-grade cases. In those 10 cases, a considerable number of CD4-positive T cells infiltrated into lymphoma cells and RAG-1 was also prominently expressed. Based on these findings, it was thus assumed that the normal counterpart of gastric B cell lymphoma of MALT type is different from the conventional B cell lymphoma, and the restricted expression of V beta repertoires is therefore considered to be a characteristic finding in low-grade B cell lymphomas of MALT type as well as in a proportion of high-grade lymphomas (the so called 'high-grade lymphoma of MALT type').

Use of an intratracheal silicone prosthesis (Dumon type) for the treatment of tracheoesophageal fistula due to advanced lung cancer

A 49-year-old woman with a tracheoesophageal fistula due to advanced lung cancer was successfully treated by a stent using an intratracheal silicone prosthesis (Dumon type). The use of a Dumon tube proved to effectively palliate the fistulization and thus resulted in a dramatic improvement of the patient's quality of life.

Inhibition of lipid peroxidation and the active oxygen radical scavenging effect of anthocyanin pigments isolated from Phaseolus vulgaris L

No attention has been paid to anthocyanin pigments from the viewpoint of inhibitors of lipid peroxidation and scavengers of active oxygen radicals; therefore, we investigated the antioxidative, radical scavenging, and inhibitory effects on lipid peroxidation by UV light irradiation of three anthocyanin pigments, pelargonidin 3-O-beta-D-glucoside (P3G), cyanidin 3-O-beta-D-glucoside (C3G), and delphinidin 3-O-beta-D-glucoside (D3G), isolated from the Phaseolus vulgaris L. seed coat, and their aglycons, pelargonidin chloride (Pel), cyanidin chloride (Cy), and delphinidin chloride (Del). All pigments had strong antioxidative activity in a liposomal system and reduced the formation of malondialdehyde by UVB irradiation. On the other hand, the extent of antioxidative activity in a rat liver microsomal system and the scavenging effect of hydroxyl radicals (-OH) and superoxide anion radicals (O2-) were influenced by their own structures.

Primary cutaneous T-cell lymphoma with an angiocentric growth pattern: association with Epstein-Barr virus

We report a case of primary cutaneous T-cell lymphoma with an angiocentric growth pattern. The lesions had been confined for about 2.5 years to the skin, but there had been a gradual progression of the disease both clinically and histologically. We assessed the neoplastic clonality and the presence of Epstein-Barr (EB) virus genome in this case using immunohistochemistry, Southern blot analysis and RNA in situ hybridization. Clonal proliferation of a CD4+ alpha beta T-cell phenotype was demonstrated. In addition, the clonal population harboured the EB virus genome, which suggested that the virus was involved in the pathogenesis of the disease. The patient has remained in remission for 10 months, and has received treatment with cyclophosphamide and prednisone.

The complete nucleotide sequence of turnip mosaic virus RNA Japanese strain

The complete nucleotide sequence of the RNA genome of turnip mosaic virus Japanese strain (TuMV-J) has been determined from five overlapping cDNA clones and by direct sequencing of viral RNA. The RNA sequence was 9833 nucleotides in length, excluding a 3' terminal poly(A) tail. An AUG triplet at position 130-132 was assigned as the initiation codon for the translation of the genome size viral polyprotein which would consist of 3164 amino acid residues. Interestingly, a different amino acid sequence (continuous twenty amino acids) within the cytoplasmic inclusion protein between TuMV-J and Canadian strain of TuMV was observed, caused by an insertion and a deletion of nucleotides.

Determination of the chiral structure of [Formula: see text] using anomalous x-ray scattering near the Cs K absorption edge

A structural study of [Formula: see text], grown from aqueous solution, was performed using anomalous x-ray scattering near the Cs K absorption edge to determine an absolute configuration of constituent atoms. The sense of the helical structure of the [Formula: see text] chain was found to be predominantly right-handed through a comparison of observed Bragg Bijvoet ratios with calculated ones. Assuming that [Formula: see text] consists of the two domains (i.e. right- and left-handed helices), we estimate that the volume fraction for the right-handed helix is [Formula: see text].

Classical Hodgkin and Reed-Sternberg cells demonstrate a non-clonal immature B lymphoid lineage: evidence from a single cell assay and in situ hybridization

Hodgkin and Reed-Sternberg (H & RS) cells are generally considered to be the neoplastic cells of Hodgkin's disease (HD), however such cells are only found in a minority of the lesions. Recently in a few studies on HD, the clonality of H & RS cells was examined, using a single-cell polymerase chain reaction (PCR) examination. To clarify the lineage and clonality of H & RS cells, we performed single cell PCR and in situ hybridization (ISH), and nine cases of classical HD were thus studied. By ISH, the immunoglobulin J chain, and the kappa and lambda light chain were rarely expressed in the H & RS cells, however, no T-cell markers could be detected. The expression of the recombination activating genes (RAG-1, 2) could be determined in the H & RS cells. We isolated CD30+ H & RS cells, CD3 + T cells and CD20 + B cells from suspended materials using a mechanical sorter. We performed single cell PCR in a sorted individual cell, to amplify the complementarity determining region of the Ig heavy chain (IgH) gene and T-cell receptor gamma chain (TCR gamma) gene. In all cases, TCR gamma could be frequently amplified in the T cells, but was only rarely amplified in the H & RS and B cells. In contrast, the IgH was frequently amplified in the H & RS and B cells, but not in the T cells. In addition, the PCR production of the H & RS cells all showed different lengths. The results therefore support the polyclonal nature and immature B lymphoid cell origin of H & RS cells.

Primary gastrointestinal T-cell lymphoma resembling multiple lymphomatous polyposis

An extremely rare case of primary gastrointestinal T-cell lymphoma involving the stomach and intestine is reported. Radiographic and endoscopic examinations showed multiple polypoid lesions covered by a normal-appearing mucosa in the stomach, duodenal bulb, and terminal ileum and numerous small aphthoid lesions throughout the entire colorectum. Histopathologic, immunohistochemical, and polymerase chain reaction studies were performed using paraffin-embedded or fresh-frozen specimens from endoscopic biopsies and endoscopic mucosal resections. All lesions were composed of small, atypical lymphoid cells, which were classified as low-grade pleomorphic lymphoma. The tumor cells expressed CD3, CD4, and the T-cell receptor gamma gene phenotype as well as human mucosal lymphocyte 1 antigen, suggesting that the lymphoma cells were derived from intraepithelial T lymphocytes. This is the first description of primary gastrointestinal T-cell lymphoma with expression of human mucosal lymphocyte 1 antigen and a novel morphology resembling multiple lymphomatous polyposis.

Apoptosis and proliferation in gastric carcinoma: the association with histological type

We examined apoptosis in 33 gastric carcinomas using the terminal deoxynucleotydil transferase mediated dUTP-digoxigenin nick end labelling technique (TUNEL). Of the tumours, nine were well-differentiated, 13 moderately differentiated and 11 poorly differentiated. In addition, we also analysed MIB-1, a cell proliferation antigen. Morphologically, apoptotic tumour cells were more frequently observed in well-differentiated tumours. In addition, apoptotic signals of the TUNEL method were seen even in the nuclei of tumour cells which did not show apoptosis. The nick end labelling index was 51.0 +/- 26.3 in the well-differentiated and moderately differentiated tumours and 28.0 +/- 18.8 in poorly differentiated tumours. The mean of apoptotic body index and nick end labelling index were both significantly higher in well-differentiated and moderately differentiated tumours than in the poorly differentiated type (P < 0.0001, P = 0.008). The MIB-1 labelling index and higher in poorly differentiated tumours than in the well-differentiated or moderately differentiated tumours, and labelled cells were more numerous in the superficial region than in the middle and deep regions of tumours. No apparent correlation was found between the nick end labelling index and the MIB-1 labelling index. The high number of apoptotic cells (the high Nick end labelling index) and low proliferation potentiality (the low MIB-1 labelling index) in well-differentiated gastric carcinomas may thus be related to their natural tendency to demonstrate slow growth.

TTA.TAA triplet repeats in plasmids form a non-H bonded structure

CTG.CAG, CGG.CCG, and AAG.CTT triplet repeats proximal to or in disease genes expand by a non-Mendelian genetic process to cause several human hereditary syndromes. As part of our physical, biological, and genetic studies on the 10 possible triplet repeats, we discovered that the TTA.TAA repeat, isolated from the upstream region of the variant surface glycoprotein gene of Trypanosoma brucei, shows a propensity to adopt a non-H bonded structure under appropriate conditions. The other nine triplet repeat sequences do not exhibit this property. (TTA.TAA)n, where n = 90, 60, 30, and 18, cloned into pUC19 was studied by chemical and enzymatic probes as well as two-dimensional gel electrophoretic analyses under a variety of conditions. The helix opening was observed for all four inserts in supercoiled plasmids as a function of temperature, pH, metal ions, and buffer conditions using OsO4, diethyl pyrocarbonate, and chloroacetaldehyde probes. This unusual property of the TTA.TAA repeat suggests that it plays a different role from the other nine triplet repeats in gene expression.

Cloning, characterization, and properties of seven triplet repeat DNA sequences

Several neuromuscular and neurodegenerative diseases are caused by genetically unstable triplet repeat sequences (CTG.CAG, CGG.CCG, or AAG.CTT) in or near the responsible genes. We implemented novel cloning strategies with chemically synthesized oligonucleotides to clone seven of the triplet repeat sequences (GTA.TAC, GAT.ATC, GTT.AAC, CAC.GTG, AGG.CCT, TCG.CGA, and AAG.CTT), and the adjoining paper (Ohshima, K., Kang, S., Larson, J. E., and Wells, R. D.(1996) J. Biol. Chem. 271, 16784-16791) describes studies on TTA.TAA. This approach in conjunction with in vivo expansion studies in Escherichia coli enabled the preparation of at least 81 plasmids containing the repeat sequences with lengths of approximately 16 up to 158 triplets in both orientations with varying extents of polymorphisms. The inserts were characterized by DNA sequencing as well as DNA polymerase pausings, two-dimensional agarose gel electrophoresis, and chemical probe analyses to evaluate the capacity to adopt negative supercoil induced non-B DNA conformations. AAG.CTT and AGG.CCT form intramolecular triplexes, and the other five repeat sequences do not form any previously characterized non-B structures. However, long tracts of TCG.CGA showed strong inhibition of DNA synthesis at specific loci in the repeats as seen in the cases of CTG.CAG and CGG.CCG (Kang, S., Ohshima, K., Shimizu, M., Amirhaeri, S., and Wells, R. D.(1995) J. Biol. Chem. 270, 27014-27021). This work along with other studies (Wells, R. D.(1996) J. Biol. Chem. 271, 2875-2878) on CTG.CAG, CGG.CCG, and TTA.TAA makes available long inserts of all 10 triplet repeat sequences for a variety of physical, molecular biological, genetic, and medical investigations. A model to explain the reduction in mRNA abundance in Friedreich's ataxia based on intermolecular triplex formation is proposed.

Angiocentric immunoproliferative lesions of the lymph node

Clinicopathologic features in 14 cases of lymph node-involved angiocentric immunoproliferative lesions (AILs) are reported. They were selected from 900 cases of lymphoproliferative disorders registered at the Department of Pathology, Fukuoka University. Four cases showed a histologic feature of AIL grade II (AIL-II) and 10 had angiocentric lymphoma (AIL-III). Immunohistologically, transformed B cells were mixed with a large number of small T cells in AIL-II. In AIL-III, there were five cases with B-cell lymphoma, and three had peripheral T-cell lymphoma with no expression of natural-killer (NK)-associated antigens. In the remaining two cases, lymphoma cells expressed both T-cell- and NK-associated antigens. These findings indicate that lymph node-involved AILs are rarely occurring (1.6%) and phenotypically different from sinonasal and cutaneous AILs. Furthermore, NK-associated antigen-positive AILs were found to rarely involve the lymph node. For Epstein-Barr virus (EBV) infection, seven cases of AILs showed many atypical lymphocytes that were positive for EBV-encoded RNA (EBER-1) by using the in situ hybridization analysis. Among them, six cases had latent membrane protein (LMP) positive and EBV nuclear antigen 2 (EBNA-2) negative atypical lymphocytes. The pattern of latent EBV infection was similar to that of Hodgkin's disease, but differed from those of sinonasal T-cell lymphoma and other subtypes of non-Hodgkin's lymphoma. Clinically, 12 patients, including all 4 AIL-II, died within 22 months of the onset of the disease, despite intensive therapy, suggesting that lymph node-involved AILs have a poor prognosis.

The 3' ends of tRNA-derived short interspersed repetitive elements are derived from the 3' ends of long interspersed repetitive elements

Short interspersed repetitive elements (SINEs) are a type of retroposon, being members of a class of informational molecules that are amplified via cDNA intermediates and flow back into the host genome. In contrast to retroviruses and retrotransposons, SINEs do not encode the enzymes required for their amplification, such as reverse transcriptases, so they are presumed to borrow these enzymes from other sources. In the present study, we isolated a family of long interspersed repetitive elements (LINEs) from the turtle genome. The sequence of this family was found to be very similar to those of the avian CR1 family. To our surprise, the sequence at the 3' end of the LINE in the turtle genome was nearly identical to that of a family of tortoise SINEs. Since CR1-like LINEs are widespread in birds and in many other reptiles, including the turtle, and since the tortoise SINEs are only found in vertical-necked turtles, it seems possible that the sequence at the 3' end of the tortoise SINEs might have been generated by recombination with the CR1-like LINE in a common ancestor of vertical-necked turtles, after the divergence of side-necked turtles. We extended our observations to show that the 3'-end sequences of families of several tRNA-derived SINEs, such as the salmonid HpaI family, the tobacco TS family, and the salmon SmaI family, might have originated from the respective LINEs. Since it appears reasonable that the recognition sites of LINEs for reverse transcriptase are located within their 3'-end sequences, these results provide the basis for a general scheme for the mechanism by which SINEs might acquire retropositional activity. We propose here that tRNA-derived SINEs might have been generated by a recombination event in which a strong-stop DNA with a primer tRNA, which is an intermediate in the replication of certain retroviruses and long terminal repeat retrotransposons, was directly integrated at the 3' end of a LINE.

Detection of human T lymphotrophic virus type I (HTLV-I) DNA and mRNA in individual cells by polymerase chain reaction (PCR) in situ hybridization (ISH) and reverse transcription (RT)-PCR ISH

Human T lymphotrophic virus type I (HTLV-I) proviral DNA and mRNA in the blood obtained directly from HTLV-I infected adult T cell leukemia (ATL) patients were amplified by the polymerase chain reaction (PCR), and reverse transcription (RT)-PCR, and then were hybridized to fluorescein-labelled probes by means of in situ hybridization (ISH). Before the cytospin samples were prepared, heterogenous cell populations were reproducibly resolved into HTLV-I-positive and -negative distributions. Immunohistochemical staining was performed, using anti-fluorescein monoclonal antibody. Microscopic observations demonstrated a preserved cellular morphology. The intranuclear localization of amplified DNA products of proviral HTLV-I by PCR/ISH, and intracytoplasmic localization of amplified DNA of HTLV-I tax/rex mRNA by RT-PCR/ISH were maintained. In this study, about one in 10 HTLV-I provirus integrated cells expressed low copies of tax/rex mRNA. In HTLV-I-negative cell lines, amplified DNA was not observed by either PCR/ISH or RT-PCR/ISH. With the use of this technique it is thus possible to detect single-copy DNA and a few copies of mRNA, and it is therefore possible to study, not only suspended materials, but also other tissue materials for further characterization, in association with the localization of the HTLV-I infected cells.

CTG triplet repeats from the myotonic dystrophy gene are expanded in Escherichia coli distal to the replication origin as a single large event

The expansion and contraction of CTG and CGG trinucleotide repeat sequences have been associated with several heritable genetic diseases. We developed a system for investigating the expansion of triplet repeat sequences in Escherichia coli in order to elucidate molecular mechanisms. Analysis of expanded regions using the interrupting CTA triplet sequence as a location marker within the CTG tract revealed that the expansion of large CTG repeats is one event rather than an accumulation of multiple small expansions and that the expansions occur more frequently in the region distal from the replication origin. Also, we showed that a loss of interruptions increases the expansion frequency. Thus, the instability of large triplet repeats in hereditary diseases occurs by a mechanism different from the instability in microsatellite sequences caused by defects in mismatch repair systems for certain sporadic cancers and hereditary non-polyposis colorectal cancers.

Analysis of the Epstein-Barr viral genome in so-called malignant histiocytosis syndrome

Malignant histiocytosis has been described as a proliferation of morphologically atypical histiocytes, but it is difficult to determine whether or not malignant proliferation is present based on morphology alone. Recently the disorder has been thought to be heterogeneous, and therefore a true histiocytic origin is considered to be rare. The Epstein-Barr virus (EBV) is thought to have the ability to transform human cells. Therefore, eight cases of malignant histiocytic (MH) syndrome and five cases of virus-associated hemophagocytic syndrome (VAHS) were analyzed using a polymerase chain reaction (PCR) and the in situ hybridization (ISH) method in order to determine their relationship to EBV infection. At the same time, the cellular origin of these syndromes was also studied. The results indicated that three of the MH cases were derived from T cells while four the MH cases were from histiocytes. The amplification of the EBV-LYDMA region, which was used to determine the monoclonality, was detected in two MH cases and one VAHS case, and all these cases showed only one band. An ISH study also demonstrated the presence of an EBV in these three cases. One of the EBV-positive cases revealed an amplification of the EBV-LYDMA region by the PCR method before showing any sign of MH clinically. In the VAHS cases, the EBV genome was detected in hemophagocytic cells. The EBV-positive cases all demonstrated a rapid clinical course. Based on these results it is possible that EBV infection causes similar rapid clinical features in some cases of both MH and VAHS by the same mechanism.

Random suppression of T cells that bear specific T cell receptor V beta sequences in adult T cell leukemia/lymphoma (ATLL) patients at each clinical stage: carrier, smoldering, chronic, and acute

Human T cell leukemia virus type I (HTLV-I) is associated with adult T cell leukemia/lymphoma (ATLL), which is well known as a T cell malignancy. In order to clarify whether HTLV-I plays a role as a virus-encoded superantigen in the neoplastic process, we examined the TCR V beta families in the peripheral blood at four different clinical stages: carrier, smoldering leukemia, chronic leukemia, and acute leukemia. An increased number of CD4 T cells was found in each of the four clinical stages. However, we found neither uniform specific losses nor uniform clonal expansion of particular TCR V beta gene families in any case from the four clinical stages. However, a suppression of the random TCR V beta families was found. Our data did not therefore directly suggest the existence of a common superantigen model of HTLV-I which induces an increase in CD4 T cells. The random suppression in the TCR V beta repertoire is most likely caused by the influence of HTLV-I neoplastic pathogenesis rather than by virus-encoded superantigens. In the patients with acute leukemia, one or two families of the V beta repertoires were very strongly expressed, while in chronic leukemia, no such repertoire of strong expression was observed. The immunological reaction of the hosts might thus be different between the above described groups.

Epstein-Barr virus infection and associated products (LMP, EBNA2, vIL-10) in nodal non-Hodgkin's lymphoma of human immunodeficiency virus-negative Japanese

Sixty cases of B-cell nodal non-Hodgkin's malignant lymphoma (B-ML), and 46 cases of T-cell nodal lymphoma (T-ML) were surveyed for Epstein-Barr virus (EBV) genomes, RNA, and associated proteins. We used a Southern blot analysis, polymerase chain reaction (PCR), and EBV-encoded small RNA-1 (EBER-1) in situ hybridization to investigate the presence of EBV. We performed an immunohistochemical study on EBV-related oncoproteins, such as EBV-determined nuclear antigen-2 (EBNA-2), latent membrane protein (LMP), and viral interleukin-10 (vIL-10). In addition, we also analyzed the terminal repetitive sequence of EBV (EBV-TR) to investigate the EBV-infected cell clonality. Non-Hodgkin's lymphomas were grouped into three types by number of EBV-infected cells: I) almost all lymphoma cells showed an EBV presence; II) some scattered lymphoma cells showed an EBV presence; and III) only a few cells showed such a presence, which was probably due to a latent EBV infection. In 25 of 60 B-MLs, EBV-infected cells were found; 7 were type I, 1 was type II, and 17 were type III. In 27 of 46 T-MLs, EBV-infected cells were found; no cases were type I, 5 cases were type II, and 22 cases were type III. Seven B-MLs and 3 T cell lymphomas showed clonal TR bands. Expression of EBNA-2 was found in only three B-MLs, whereas LMP was seen in four B-MLs and six T-MLs. All EBNA-2/LMP-positive cases showed an EBV presence. In B-MLs, expression of EBNA-2 and LMP was detected in almost all lymphoma cells; in T-MLs, however, LMP was found in only a small portion of the lymphoma cells. Expression of IL-10 was closely associated with LMP. In summary, it was thus speculated that EBV infection was associated with the various states of lymphomagenesis.

Complete nucleotide sequence and synthesis of infectious in vitro transcripts from a full-length cDNA clone of a rakkyo strain of tobacco mosaic virus

The complete nucleotide sequence of the genome of a rakkyo strain of tobacco mosaic virus (TMV-R), which exhibits distinct host range differences from the common strain of TMV, was determined. The overall nucleotide sequence homology with TMV-U1 (a common strain of TMV) is 94.2%. The amino acid sequence homologies of the four encoded proteins (180K, 130K, 30K, coat protein) are from 95.9% to 98.0% compared with TMV-U1. To facilitate the analysis of the novel host range of TMV-R, a full-length clone of the genome containing a bacteriophage T7 RNA polymerase promoter was assembled from two cDNA clones and designated pRF3. In vitro transcripts derived from pRF3 were highly infectious. The infections of RF3, wild-type TMV-R, and U3/12-4 (derived from pU3/12-4, an infectious clone of TMV-U1) were compared on Nicotiana tabacum cv. Bright Yellow (BY) plants. No systemic mosaic symptoms were observed on plants inoculated with RF3 and TMV-R, while BY plants inoculated with U3/12-4 developed distinct mosaic symptoms on the upper leaves 8-9 days post-inoculation. The green fluorescent protein (GFP) gene was introduced into pRF3 and pU3/12-4 by replacing the coat protein gene to get two GFP expressing chimeric virus clones: pR-GFP or pU1-GFP. Transcripts from pU1-GFP produced strong fluorescence when inoculated onto BY leaves, while those from pR-GFP produced only very faint fluorescence.