scholarly journals Localization of Complement-fixing Antigens in Cells: Epstein-Barr Virus-induced Membrane and Interior Cell Antigens

1971 ◽  
Vol 13 (3) ◽  
pp. 441-447 ◽  
Author(s):  
A. Hollinshead ◽  
O. Lee ◽  
T. C. Alford
Keyword(s):  
Epstein Barr Virus ◽  
Induced Membrane ◽  
Barr Virus ◽  
Epstein Barr ◽  
Interior Cell ◽  
In Cells

scholarly journals Microtubule depolymerization activates the Epstein–Barr virus lytic cycle through protein kinase C pathways in nasopharyngeal carcinoma cells

2013 ◽  
Vol 94 (12) ◽  
pp. 2750-2758 ◽  
Author(s):  
Yi-Ru Liu ◽  
Sheng-Yen Huang ◽  
Jen-Yang Chen ◽  
Lily Hui-Ching Wang
Keyword(s):  
Protein Kinase C ◽  
Life Cycle ◽  
Protein Kinase ◽  
Nasopharyngeal Carcinoma ◽  
Epstein Barr Virus ◽  
Lytic Cycle ◽  
Barr Virus ◽  
Kinase C ◽  
Epstein Barr ◽  
In Cells

Elevated levels of antibodies against Epstein–Barr virus (EBV) and the presence of viral DNA in plasma are reliable biomarkers for the diagnosis of nasopharyngeal carcinoma (NPC) in high-prevalence areas, such as South-East Asia. The presence of these viral markers in the circulation suggests that a minimal level of virus reactivation may have occurred in an infected individual, although the underlying mechanism of reactivation remains to be elucidated. Here, we showed that treatment with nocodazole, which provokes the depolymerization of microtubules, induces the expression of two EBV lytic cycle proteins, Zta and EA-D, in EBV-positive NPC cells. This effect was independent of mitotic arrest, as viral reactivation was not abolished in cells synchronized at interphase. Notably, the induction of Zta by nocodazole was mediated by transcriptional upregulation via protein kinase C (PKC). Pre-treatment with inhibitors for PKC or its downstream signalling partners p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) abolished the nocodazole-mediated induction of Zta and EA-D. Interestingly, the effect of nocodazole, as well as colchicine and vinblastine, on lytic gene expression occurred only in NPC epithelial cells but not in cells derived from lymphocytes. These results establish a novel role of microtubule integrity in controlling the EBV life cycle through PKC and its downstream pathways, which represents a tissue-specific mechanism for controlling the life-cycle switch of EBV.

scholarly journals Modulation of Epstein-Barr Virus Glycoprotein B (gB) Fusion Activity by the gB Cytoplasmic Tail Domain

mBio ◽  
2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Nicholas J. Garcia ◽  
Jia Chen ◽  
Richard Longnecker
Keyword(s):  
Membrane Fusion ◽  
Epstein Barr Virus ◽  
Cytoplasmic Tail ◽  
Host Cells ◽  
Glycoprotein B ◽  
Tail Domain ◽  
Induced Membrane ◽  
Barr Virus ◽  
Cellular Expression ◽  
Epstein Barr

ABSTRACTEpstein-Barr virus (EBV), along with other members of the herpesvirus family, requires a set of viral glycoproteins to mediate host cell attachment and entry. Viral glycoprotein B (gB), a highly conserved glycoprotein within the herpesvirus family, is thought to be the viral fusogen based on structural comparison of EBV gB and herpes simplex virus (HSV) gB with the postfusion crystal structure of vesicular stomatitis virus fusion protein glycoprotein G (VSV-G). In addition, mutational studies indicate that gB plays an important role in fusion function. In the current study, we constructed a comprehensive library of mutants with truncations of the C-terminal cytoplasmic tail domain (CTD) of EBV gB. Our studies indicate that the gB CTD is important in the cellular localization, expression, and fusion function of EBV gB. However, in line with observations from other studies, we conclude that the degree of cell surface expression of gB is not directly proportional to observed fusion phenotypes. Rather, we conclude that other biochemical or biophysical properties of EBV gB must be altered to explain the different fusion phenotypes observed.IMPORTANCEEpstein-Barr virus (EBV), like all enveloped viruses, fuses the virion envelope to a cellular membrane to allow release of the capsid, resulting in virus infection. To further characterize the function of EBV glycoprotein B (gB) in fusion, a comprehensive library of mutants with truncations in the gB C-terminal cytoplasmic tail domain (CTD) were made. These studies indicate that the CTD of gB is important for the cellular expression and localization of gB, as well as for the function of gB in fusion. These studies will lead to a better understanding of the mechanism of EBV-induced membrane fusion and herpesvirus-induced membrane fusion in general, which will ultimately lead to focused therapies guided at preventing viral entry into host cells.

Immunoglobulin a Antibody to Epstein-Barr Viral Antigens and Prognosis in Nasopharyngeal Carcinoma

1980 ◽  
Vol 88 (1) ◽  
pp. 52-57 ◽  
Author(s):  
Gregory D. Mathew ◽  
Louis F. Qualtiere ◽  
H. Bryan Neel ◽  
Gary R. Pearson
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Epstein Barr Virus ◽  
Immunoglobulin A ◽  
Antibody Dependent Cellular Cytotoxicity ◽  
Induced Membrane ◽  
Barr Virus ◽  
Iga Antibodies ◽  
Adcc Assay ◽  
Membrane Antigens ◽  
Epstein Barr

IgA immunoglobulin fractions containing antibodies to Epstein-Barr virus (EBV)-induced membrane antigens were isolated from the sera of two patients with nasopharyngeal carcinoma (NPC), from one non-NPC patient, and from three persons with sera negative for IgA antibodies. IgA antibodies were not cytotoxic against cells expressing EBV-induced membrane antigens in the antibody-dependent cellular cytotoxicity (ADCC) assay. However, IgA antibodies blocked IgG-mediated ADCC, which indicated that these antibodies could serve as a blocking “factor” in patients with disease and, therefore, were potentially detrimental to the host.

scholarly journals MicroRNA-155 Is an Epstein-Barr Virus-Induced Gene That Modulates Epstein-Barr Virus-Regulated Gene Expression Pathways

2008 ◽  
Vol 82 (11) ◽  
pp. 5295-5306 ◽  
Author(s):  
Qinyan Yin ◽  
Jane McBride ◽  
Claire Fewell ◽  
Michelle Lacey ◽  
Xia Wang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Epstein Barr Virus ◽  
Type I ◽  
Type Iii ◽  
Barr Virus ◽  
Transcriptional Regulatory ◽  
Infected Cells ◽  
Epstein Barr ◽  
Regulated Gene Expression ◽  
In Cells

ABSTRACT The cellular microRNA miR-155 has been shown to be involved in lymphocyte activation and is expressed in Epstein-Barr virus (EBV)-infected cells displaying type III latency gene expression but not type I latency gene expression. We show here that the elevated levels of miR-155 in type III latency cells is due to EBV gene expression and not epigenetic differences in cell lines tested, and we show that expression in EBV-infected cells requires a conserved AP-1 element in the miR-155 promoter. Gene expression analysis was carried out in a type I latency cell line transduced with an miR-155-expressing retrovirus. This analysis identified both miR-155-suppressed and -induced cellular mRNAs and suggested that in addition to direct targeting of 3′ untranslated regions (UTRs), miR-155 alters gene expression in part through the alteration of signal transduction pathways. 3′ UTR reporter analysis of predicted miR-155 target genes identified the transcriptional regulatory genes encoding BACH1, ZIC3, HIVEP2, CEBPB, ZNF652, ARID2, and SMAD5 as miR-155 targets. Western blot analysis of the most highly suppressed of these, BACH1, showed lower expression in cells transduced with a miR-155 retrovirus. Inspection of the promoters from genes regulated in EBV-infected cells and in cells infected with an miR-155 retrovirus identified potential binding sequences for BACH1 and ZIC3. Together, these experiments suggest that the induction of miR-155 by EBV contributes to EBV-mediated signaling in part through the modulation of transcriptional regulatory factors.

scholarly journals The Epstein-Barr Virus (EBV) gN Homolog BLRF1 Encodes a 15-Kilodalton Glycoprotein That Cannot Be Authentically Processed unless It Is Coexpressed with the EBV gM Homolog BBRF3

1998 ◽  
Vol 72 (7) ◽  
pp. 5559-5564 ◽  
Author(s):  
Cathleen M. Lake ◽  
Sara J. Molesworth ◽  
Lindsey M. Hutt-Fletcher
Keyword(s):  
Sialic Acid ◽  
Recombinant Protein ◽  
Epstein Barr Virus ◽  
Open Reading Frame ◽  
Reading Frame ◽  
Mature Form ◽  
Barr Virus ◽  
Epstein Barr ◽  
Antipeptide Antibody ◽  
In Cells

ABSTRACT The Epstein-Barr virus (EBV) homolog of the conserved herpesvirus glycoprotein gN is predicted to be encoded by the BLRF1 open reading frame (ORF). Antipeptide antibody to a sequence corresponding to residues in the predicted BLRF1 ORF immunoprecipitated a doublet of approximately 8 kDa from cells expressing the BLRF1 ORF as a recombinant protein. In addition, four glycosylated proteins of 113, 84, 48, and 15 kDa could be immunoprecipitated from virus-producing cells by the same antibody. The 15-kDa species was the mature form of gN, which carried α2,6-sialic acid residues. The remaining glycoproteins which associated with gN were products of the BBRF3 ORF of EBV, which encodes the EBV gM homolog. The 8-kDa doublet seen in cells expressing recombinant gN comprised precursors of the mature 15-kDa gN. Coexpression of EBV gM with EBV gN was required for authentic processing of the 8-kDa forms to the 15-kDa form.

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