The Replisome Pausing Factor Timeless Is Required for Episomal Maintenance of Latent Epstein-Barr Virus

Vectors carrying the origin of replication (oriP) and driving expression of the EBNA-1 protein from Epstein–Barr virus (EBV) replicate as extrachromosomal episomes in human cells. Whether these vectors can be maintained as episomes in murine cells is still controversial. Here we demonstrate that EBNA-1 expression alone was unable to maintain episomal expression of an EBV-based vector in the murine Sp2/0 cell line. However, we were able to obtain long-term episome maintenance in Sp2/0 cells after exogenously expressing human EBP2 by genetic engineering. Our results provide further evidence for the fundamental role of human EBP2 in episomal maintenance of EBV-based vectors. Moreover, we demonstrate that EBV-based vectors can be successfully used in cells presumably incompetent for episomal maintenance.Key words: EBV vector, EBNA-1, EBP2, episomal maintenance, mouse cell, Sp2/0 myeloma cell line.

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Telomeric Proteins Regulate Episomal Maintenance of Epstein-Barr Virus Origin of Plasmid Replication

Molecular Cell ◽

10.1016/s1097-2765(02)00476-8 ◽

2002 ◽

Vol 9 (3) ◽

pp. 493-503 ◽

Cited By ~ 101

Author(s):

Zhong Deng ◽

Larissa Lezina ◽

Chi-Ju Chen ◽

Svetlana Shtivelband ◽

Wingkan So ◽

...

Keyword(s):

Epstein Barr Virus ◽

Plasmid Replication ◽

Barr Virus ◽

Virus Origin ◽

Epstein Barr ◽

Episomal Maintenance

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Establishment of Latent Epstein-Barr Virus Infection and Stable Episomal Maintenance in Murine B-Cell Lines

Journal of Virology ◽

10.1128/jvi.75.6.3016-3020.2001 ◽

2001 ◽

Vol 75 (6) ◽

pp. 3016-3020 ◽

Cited By ~ 17

Author(s):

Keith M. Haan ◽

Ashok Aiyar ◽

Richard Longnecker

Keyword(s):

B Cell ◽

Viral Entry ◽

Epstein Barr Virus ◽

Small Animal ◽

Nuclear Antigen ◽

Epstein Barr Virus Infection ◽

Barr Virus ◽

Epstein Barr ◽

Barr Virus Infection ◽

Episomal Maintenance

ABSTRACT Epstein-Barr virus (EBV) is a strict human pathogen for which no small animal models exist. Plasmids that contain the EBV plasmid origin of replication, oriP, and express EBV nuclear antigen 1 (EBNA1) are stably maintained extrachromosomally in human cells, whereas these plasmids replicate poorly in rodent cells. However, the ability of oriP and EBNA1 to maintain the entire EBV episome in proliferating rodent cells has not been determined. Expression of the two human B-cell receptors for EBV on the surfaces of murine B cells allows efficient viral entry that leads to the establishment of latent EBV infection and long-term persistence of the viral genome. Latent gene expression in these cells resembles the latency II profile in that EBNA1 and LMP1 can be detected whereas EBNA2 and the EBNA3s are not expressed.

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A Quantitative Ultrastructural Study of Peripheral Blood Lymphocytes Containing Parallel Tubular Arrays in Epstein-Barr Virus and Cytomegalo-Virus Mononucleosis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100098769 ◽

1981 ◽

Vol 39 ◽

pp. 454-455

Author(s):

C. M. Payne ◽

P. M. Tennican

Keyword(s):

Peripheral Blood ◽

Lymphocyte Count ◽

Epstein Barr Virus ◽

Absolute Lymphocyte Count ◽

Peripheral Blood Lymphocytes ◽

Clinical State ◽

Barr Virus ◽

The Absolute ◽

Epstein Barr ◽

Tubular Arrays

In the normal peripheral circulation there exists a sub-population of lymphocytes which is ultrastructurally distinct. This lymphocyte is identified under the electron microscope by the presence of cytoplasmic microtubular-like inclusions called parallel tubular arrays (PTA) (Figure 1), and contains Fc-receptors for cytophilic antibody. In this study, lymphocytes containing PTA (PTA-lymphocytes) were quantitated from serial peripheral blood specimens obtained from two patients with Epstein -Barr Virus mononucleosis and two patients with cytomegalovirus mononucleosis. This data was then correlated with the clinical state of the patient.It was determined that both the percentage and absolute number of PTA- lymphocytes was highest during the acute phase of the illness. In follow-up specimens, three of the four patients' absolute lymphocyte count fell to within normal limits before the absolute PTA-lymphocyte count.In one patient who was followed for almost a year, the absolute PTA- lymphocyte count was consistently elevated (Figure 2). The estimation of absolute PTA-lymphocyte counts was determined to be valid after a morphometric analysis of the cellular areas occupied by PTA during the acute and convalescent phases of the disease revealed no statistical differences.

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Studies of Epstein-Barr Virus Antigens Using Immunoperoxidase and Immunofluorescence Techniques

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010011533x ◽

1975 ◽

Vol 33 ◽

pp. 342-343

Author(s):

R. Stephens ◽

K. Traul ◽

D. Woolf ◽

P. Gaudreau

Keyword(s):

Electron Microscopy ◽

Nasopharyngeal Carcinoma ◽

Epstein Barr Virus ◽

Barr Virus ◽

If Technique ◽

Infected Cells ◽

Virus Antigens ◽

Epstein Barr ◽

Virus Capsid Antigen ◽

Antigen Reactivity

A number of antigens have been found associated with persistent EBV infections of lymphoblastoid cells. Identification and localization of these antigens were principally by immunofluorescence (IF) techniques using sera from patients with nasopharyngeal carcinoma (NPC), Burkitt lymphoma (BL), and infectious mononucleosis (IM). Our study was mainly with three of the EBV related antigens, a) virus capsid antigen (VCA), b) membrane antigen (MA), and c) early antigens (EA) using immunoperoxidase (IP) techniques with electron microscopy (EM) to elucidate the sites of reactivity with EBV and EBV infected cells.Prior to labeling with horseradish peroxidase (HRP), sera from NPC, IM, and BL cases were characterized for various reactivities by the indirect IF technique. Modifications of the direct IP procedure described by Shabo and the indirect IP procedure of Leduc were made to enhance penetration of the cells and preservation of antigen reactivity.

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