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Biomedical subjects

M Nonoyama

Publications and source records attributed to M Nonoyama.

At least 127 records · Page 7Linked to original sources
PubMed1980

Comparative studies of herpesvirus papio (baboon herpesvirus) DNA and Epstein-Barr virus DNA.

An Epstein-Barr virus (EBV)-like herpesvirus has been isolated from a baboon cell line (594S/F9) by induction with the tumour promoter 12-O-tetradecanoyl-phorbol-13-acetate (TPA). The herpesvirus papio (HVP) DNA was mixed with B95 EBV DNA and was characterized by sedimentation in neutral glycerol gradient as 55S DNA, with a buoyant density of approx. 1.718 g/ml after equilibrium centrifugation in caesium chloride. DNA-DNA reassociation kinetics between B95 EBV and HVP DNA showed that HVP DNA shares about 40% homology with B95 EBV DNA. Blot hybridization of EcoRI fragments of HVP DNA with a 32P-B95 EBV DNA probe showed that most of the EcoRI fragments of HVP DNA were hybridized to B95 EBV DNA, suggesting that the homologous sequences were dispersed throughout the virus DNA.

Animals↗
PubMed1980

Replication of the resident Marek's Disease virus genome in synchronized nonproducer MKT-1 cells.

MKT-1, a virus nonproducer lymphoblastoid cell line established from a Marek's disease tumor, was synchronized by double thymidine block to determine the sequence of events in the synthesis of cellular and latent marek's disease virus DNA. Cellular DNA synthesis was measured by incorporation of [3H]thymidine, whereas viral DNA synthesis was determined by DNA-DNA reassociation kinetics. The results of these studies indicate that the resident Marek's disease viral DNA in MKT-1 cells replicates during the early S phase of the cell cycle, before the onset of active cellular DNA synthesis. This observation is similar to that seen in the replication of resident Epstein-Barr virus DNA in synchronized Raji cells.

Animals↗
PubMed1979

Transcription of the Marek's disease virus genome in virus-induced tumors.

Transcription of the Marek's disease virus (MDV) genome in tumor tissues from MDV-infected chickens has been studied by analyzing the hybridization kinetics of (3)H-labeled MDV DNA with unlabeled RNA extracted from these tissues. Lymphoid tumors of ovary, spleen, liver, and kidney contained MDV genomes, but the virus-specific RNA sequences were transcribed from less than 15% of the viral DNA. A virus nonproductive lymphoblastoid cell line, designated MKT-1, has been established from a kidney lymphoma and contains 15 MDV genomes per cell. In these cells, 12 to 14% of the viral DNA was transcribed. Thus transcription of the MDV genome was restricted both in tumor tissues and MKT-1 cells. A hybridization experiment where RNA extracted from MKT-1 cells and RNA extracted from a spleen tumor were mixed and hybridized to (3)H-labeled MDV DNA indicated that the virus-specific RNAs from the two sources were encoded by the same DNA sequences. The polyribosomal fractions of MKT-1 cells and this spleen tumor contained only a portion of the virus-specific RNA sequences found in whole-cell extracts, indicating the existence of a posttranscriptional control mechanism which prevents the transfer of certain viral RNA transcripts to the polyribosomes. The data suggest that the repressed expression of the viral genome in lymphoid tumor tissues and MKT-1 cells may be the result of precise controls within the cell at the transcriptional and posttranscriptional levels.

Animals↗
PubMed1979

Establishment of a lymphoblastoid cell line and isolation of an Epstein-Barr-related virus of gorilla origin.

A B-lymphoid cell line was established from a normal gorilla. The cells contained Epstein-Barr virus-related antigens, and herpesvirus particles were demonstrated by electron microscopy. DNA-DNA reassociation kinétics revealed 30 to 40% hybridization to Epstein-Barr virus with 50 genomes per cell. Examination of the viral nuclear antigen with gorilla sera showed this to be a unique isolate termed Herpesvirus gorilla. H. gorilla transformed gibbon B-lymphocytes in vitro.

Animals↗
PubMed1978

Further characterization of a herpesvirus-positive orang-utan cell line and comparative aspects of in vitro transformation with lymphotropic old world primate herpesviruses.

An orang-utan (Pongo pygmaeus) suspension line, CP81, was shown to lack myeloid markers of lysozyme activity an d phagocytosis but to be positive for lymphocytic N-alkaline phosphatase activity, and to release a B-cell-tropic herpesvirus. This herpesvirus, termed Herpesvirus pongo, had 30--40% DNA homology with EBV and was present at 2-3 genome copies per CP-81 cell. Gibbon lymphocytes transformed by H. pongo, Epstein-Barr virus (EBV), and H. papio (of baboon, Papio hamadryas, origin) were found to be virus antigen-positive B cells. Gibbon lymphocytes transformed by H. pongo and EBV and transplanted to nude mice by the intracranial (IC) route (had a 75% and a 45% success rate, respectively), while transplants of similar cells transformed by H. papio were only 10% successful. None of these lines transplanted subcutaneously (SC) nor manifested a high degree of colony formation in 0.33% agarose (less than or equal to 0.5%), Gibbon lymphocytes transformed by H. pongo were hypodiploid while those transformed by EBV or H. papio were diploid. CP-81 cells themselves could be transplanted both IC (100%) and SC (70%) and showed a relatively high degree of colony formation in agarose (6.4-7.6%). B95-8 cells (marmoset, Saguinus oedipus-EBV) could be transplanted IC (66%) but not SC and had a low but significant ability to grow in agarose (1.6%). 594S (baboon, P. hamadryas-H. papio) cells could be transplanted IC (25%) but not SC, and grew to very low levels in agarose (0.1%).

Alkaline Phosphatase↗
PubMed1978

Studies on the association of the Epstein-Barr virus genome and human chromosomes.

We have used human-mouse somatic cell hybrid to study the association between the EBV genome and the cellular genome. Attempts were made to identify a specific human chromosome(s) with which the EBV genome is associated. Our data suggest that at least in the mouse fibroblast/Burkitt lymphoma hybrid combination studies, the EBV genome is not associated with any specific human chromosome.

Antigens, Viral↗
PubMed1978

Epstein-Barr virus and human chromosomes: close association of the resident viral genome and the expression of the virus-determined nuclear antigen (EBNA) with the presence of chromosome 14 in human-mouse hybrid cells.

Fourteen hybrid clones derived from the fused cultures of human lymphoblastoid FV5 cells and 5-bromodeoxyuridine-resistant mouse fibroblastic MCB2 cells grown in hypoxanthine/aminopterin/thymidine selective medium were examined for the presence of Epstein-Barr virus (EBV) DNA, the expression of the virus-determined nuclear antigen (EBNA), and the presence of human chromosomes, in the course of serial passage in vitro. Among the hybrid clones tested, 3 were positive for EBV DNA and EBNA, whereas the remaining 11 were totally negative. The chromosome investigations showed that human chromosome 14 was consistently involved in all three EBV genome-positive and EBNA-positive hybrid clones, but not in any negative clones. In 10 subclones isolated from 1 of the 3 positive clones, all of which contained only chromosome 14 of the human chromosomes, a concordant segregation of EBNA, EBA DNA, and chromosome 14 was evident. These findings suggest that the resident EBV genome is closely associated with chromosome 14 and the presence of this particular chromosome alone is sufficient for the maintenance and the expression of EBV genetic information in human lymphoblastoid cells.

Antigens, Viral↗
PubMed1978

Transforming activity of Epstein-Barr virus obtained by superinfection of Raji cells.

Epstein-Barr virus obtained by superinfection of Raji cells with Epstein-Barr virus recovered from P3HR1 cells (HRI virus) transformed human lymphocytes, but it did not superinfect Raji cells. A human lymphoblastoid cell line, HLB, established by such transformation contained 22 Epstein-Barr virus genomes per cell and Epstein-Barr virus-associated nuclear antigen, and a few cells contained early or viral capsid antigen complexes. Chromosomal analysis revealed that HLB-cells were diploid with normal female karyotypes. Replication of Epstein-Barr virus DNA and inhibition of host cell DNA synthesis were observed in HLB cells after superinfection with HR1 virus.

Antigens, Viral↗
PubMed1978

Susceptibility of marmosets to Epstein-Barr virus-like baboon herpesviruses.

Epstein-Barr virus (EBV)-like herpeviruses, strains of Herpesvirus papio (HVP), have recently been isolated from lymphomatous (HVP-L) and from normal baboons (HVP-N). Both HVP isolates infect some species of marmosets, HVP-L inoculated adult animals develop a mild to severe and sometimes fatal lymphoproliferative disease whereas newborn marmosets of the same species do not develop a measureable disease after inoculation with HVP-l. HVP-N infects adult marmosets but does not cause disease.

Animals↗
PubMed1978

Athymic nude mice: induction of tumors containing Epstein-Barr virus using Burkitt's-related cell lines.

We studied tumor induction in athymic nude mice by D98/HR-1 cells, an epithelial somatic cell hybrid containing the Epstein-Barr virus (EBV) genome, and by the parental D98 and HR-1 cells. Groups of animals were inoculated with cells grown in culture, with cells from tumors induced by the cell lines, or with cells from lines derived from tumors. The tumors induced by D98/HR-1 cells were undifferentiated carcinomas; those induced by D98 cells were carcinomas and those induced by HR-1 cells were poorly differentiated lymphomas. Preliminary data suggest that the number of EBV genome equivalents was sharply reduced in cells from both D98/HR-1 and HR-1 tumors. Subsequent passage of tumor cells in vitro resulted in a partial recovery in the number of EBV genome equivalents in HR-1 cells and a complete recovery in D98/HR-1 cells. The reduction in the number of EBV genomes in the tumor cells suggests that in vitro passage can influence the number of EBV genomes in these cells.

Animals↗
PubMed1978

Expression of latent Epstein-Barr virus genomes in human epithelial/Burkitt's lymphoblastoid hybrid cells.

Expression of latent Epstein-Barr virus genomes in somatic-cell hybrids of Burkitt's lymphoblastoid cells has been studied. Treatment of the hybrid cells, D98/Raji and D98/HR-1, with IUDR induced the formation of EA and VCA and replication of virus DNA, whereas the same treatment of Raji cells induced only the formation of EA. The patterns of transcription of virus genomes in these three cell lines were, however, very similar: 25% without treatment with IUDR, 30% immediately after the treatment and 50% (entire genome transcription) three days after being transferred to fresh medium. The amount of virus RNA in the cells, calculated from DNA-RNA hybridization kinetics, was proportional to the number of virus genomes per cell, suggesting that every copy of virus DNA in these cells is actively transcribed.

Antigens, Viral↗
PubMed1978

Interaction between Epstein-Barr virus and type-C virus in human cells.

The interaction between EBV and type-C viruses was studied in our FVNC experimental system, in which EBV and type-C viral genomes are contained in each cell. The data indicate that the human lymphoid FVNC cells are sensitive to both EBV and type-C virus exposure, showing high frequencies of induction of both repressed viral genomes. The two different viral genomes may be associated with different chromosomes in individual cells.

Antigens, Viral↗