scholarly journals Plxdc family members are novel receptors for the rhesus monkey rhadinovirus (RRV)

2021 ◽  
Vol 17 (3) ◽  
pp. e1008979
Author(s):  
Anna K. Großkopf ◽  
Sarah Schlagowski ◽  
Thomas Fricke ◽  
Armin Ensser ◽  
Ronald C. Desrosiers ◽  
...  
Keyword(s):  
Rhesus Monkey ◽  
Tyrosine Kinases ◽  
Rhesus Macaques ◽  
Cell Types ◽  
Biological Difference ◽  
Cellular Receptors ◽  
Barr Virus ◽  
Glycoprotein Complex ◽  
Affinity Enrichment ◽  
Epstein Barr

The rhesus monkey rhadinovirus (RRV), a γ2-herpesvirus of rhesus macaques, shares many biological features with the human pathogenic Kaposi’s sarcoma-associated herpesvirus (KSHV). Both viruses, as well as the more distantly related Epstein-Barr virus, engage cellular receptors from the Eph family of receptor tyrosine kinases (Ephs). However, the importance of the Eph interaction for RRV entry varies between cell types suggesting the existence of Eph-independent entry pathways. We therefore aimed to identify additional cellular receptors for RRV by affinity enrichment and mass spectrometry. We identified an additional receptor family, the Plexin domain containing proteins 1 and 2 (Plxdc1/2) that bind the RRV gH/gL glycoprotein complex. Preincubation of RRV with soluble Plxdc2 decoy receptor reduced infection by ~60%, while overexpression of Plxdc1 and 2 dramatically enhanced RRV susceptibility and cell-cell fusion of otherwise marginally permissive Raji cells. While the Plxdc2 interaction is conserved between two RRV strains, 26–95 and 17577, Plxdc1 specifically interacts with RRV 26–95 gH. The Plxdc interaction is mediated by a short motif at the N-terminus of RRV gH that is partially conserved between isolate 26–95 and isolate 17577, but absent in KSHV gH. Mutation of this motif abrogated the interaction with Plxdc1/2 and reduced RRV infection in a cell type-specific manner. Taken together, our findings characterize Plxdc1/2 as novel interaction partners and entry receptors for RRV and support the concept of the N-terminal domain of the gammaherpesviral gH/gL complex as a multifunctional receptor-binding domain. Further, Plxdc1/2 usage defines an important biological difference between KSHV and RRV.

scholarly journals Use of gHgL for Attachment of Epstein-Barr Virus to Epithelial Cells Compromises Infection

2004 ◽  
Vol 78 (10) ◽  
pp. 5007-5014 ◽  
Author(s):  
Corina M. Borza ◽  
Andrew J. Morgan ◽  
Susan M. Turk ◽  
Lindsey M. Hutt-Fletcher
Keyword(s):  
Epithelial Cells ◽  
B Lymphocytes ◽  
Primary Infection ◽  
Epstein Barr Virus ◽  
Cell Types ◽  
Cellular Origin ◽  
Barr Virus ◽  
Glycoprotein Complex ◽  
Wide Range ◽  
Epstein Barr

ABSTRACT Epstein-Barr virus (EBV) is a lymphotropic herpesvirus. However, access to B lymphocytes during primary infection may be facilitated by replication in mucosal epithelial cells. Attachment and penetration of EBV into these two cell types are fundamentally different. Both the distribution of receptors and the cellular origin of the virus impact the efficiency of infection. Epithelial cells potentially offer a wide range of receptors with which virus can interact. We report here on analyses of epithelial cells expressing different combinations of receptors. We find that the stoichiometry of the virus glycoprotein complex that includes gHgL and gp42 affects the use of gHgL not just for entry into epithelial cells but also for attachment. Penetration can be mediated efficiently with either a coreceptor for gp42 or gHgL, but the use of gHgL for attachment as well as penetration greatly compromises its ability to mediate entry.

scholarly journals Plxdc family members are novel receptors for the rhesus monkey rhadinovirus (RRV)

2020 ◽  
Author(s):  
Anna K. Großkopf ◽  
Sarah Schlagowski ◽  
Thomas Fricke ◽  
Armin Ensser ◽  
Ronald C. Desrosiers ◽  
...  
Keyword(s):  
Rhesus Monkey ◽  
Rhesus Macaques ◽  
Model System ◽  
Sub Saharan Africa ◽  
Cell Type ◽  
Cellular Receptors ◽  
Affinity Enrichment ◽  
A Cell ◽  
Cell Type Specific ◽  
Receptor Family

ABSTRACTThe rhesus monkey rhadinovirus (RRV), a γ2-herpesvirus of rhesus macaques, shares many biological features with the human pathogenic Kaposi’s sarcoma-associated herpesvirus (KSHV). Both viruses, as well as the more distantly related Epstein-Barr virus, engage cellular receptors from the Eph family of receptor tyrosine kinases (Ephs). However, the importance of the Eph interaction for RRV entry varies between cell types suggesting the existence of Eph-independent entry pathways. We therefore aimed to identify additional cellular receptors for RRV by affinity enrichment and mass spectrometry. We identified an additional receptor family, the Plexin domain containing proteins 1 and 2 (Plxdc1/2) that bind the RRV gH/gL glycoprotein complex. Preincubation of RRV with soluble Plxdc2 decoy receptor reduced infection by approx. 60%, while overexpression of Plxdc1 and 2 dramatically enhanced RRV susceptibility of otherwise marginally permissive Raji cells. While the Plxdc2 interaction is conserved between two RRV strains, 26-95 and 17577, Plxdc1 specifically interacts with RRV 26-95 gH. The Plxdc interaction is mediated by a short motif at the N-terminus of RRV gH that is partially conserved between isolate 26-95 and isolate 17577, but absent in KSHV gH. Mutation of this motif abrogated the interaction with Plxdc1/2 in in vitro assays and reduced RRV infection in a cell-type specific manner. Taken together, our findings characterize Plxdc1/2 as novel interaction partners and entry receptors for RRV and support the concept of the N-terminal domain of the gammaherpesviral gH/gL complex as a multifunctional receptor-binding domain. Further, Plxdc1/2 usage defines an important biological difference between KSHV and RRV.AUTHORS SUMMARYKSHV is the causative agent of a group of malignancies which account for a substantial disease burden in particular in sub-Saharan Africa. RRV, a related virus of rhesus macaques, has shown promise as model system for KSHV and for the development of immunization strategies. To exploit the full potential of the RRV animal model system, detailed knowledge of commonalities and differences between KSHV and RRV is key. Here, we describe the Plexin domain containing proteins 1 and 2 as a novel receptor family which mediates entry of RRV, but not of KSHV. Infection experiments using RRV mutants deleted of the Plxdc interaction motif suggest a cell type-specific contribution of Plxdc receptors to RRV infection. As information on Plxdc1/2 and its biological function is still sparse, analysis of the RRV–Plxdc interaction will help to characterize the physiological and pathophysiological role of this receptor family.

scholarly journals Determination of Epstein-Barr Virus–Infected Lymphocyte Cell Types in Peripheral Blood Mononuclear Cells as a Valuable Diagnostic Tool in Hematological Diseases

2019 ◽  
Vol 6 (5) ◽  
Author(s):  
Peiling Zhang ◽  
Chen Zeng ◽  
Jiali Cheng ◽  
Jing Zhou ◽  
Jia Gu ◽  
...  
Keyword(s):  
Infected Cell ◽  
B Cell ◽  
Peripheral Blood Mononuclear Cells ◽  
Epstein Barr Virus ◽  
Nk Cell ◽  
Cell Types ◽  
Cell Type ◽  
Peripheral Blood Mononuclear ◽  
Barr Virus ◽  
Epstein Barr

Abstract Background High loads of Epstein-Barr virus (EBV) in peripheral blood mononuclear cells (PBMCs) can be indicative of a broad spectrum of diseases, ranging from asymptomatic infection to fatal cancers. Methods We retrospectively investigated the EBV-infected cell types in PBMCs among 291 patients. Based on EBV-infected cell types, the clinical features and prognoses of 93 patients with EBV-associated (EBV+) T/natural killer (NK)–cell lymphoproliferative diseases (LPDs) T/NK-LPDs) were investigated over a 5-year period. Results Although B-cell-type infection was found in immunocompromised patients and patients with asymptomatic high EBV carriage, infectious mononucleosis, EBV+ B-cell LPDs and B-cell lymphomas, T-cell, NK-cell or multiple-cell-type infection in immunocompetent hosts were highly suggestive of EBV+ T/NK-LPDs, EBV+ T/NK-cell lymphomas, and aggressive NK-cell leukemia. Patients with non–B-cell infection had a poorer prognosis than those with B-cell-type infection. In our cohort, 79.6% of patients with EBV+ T/NK-LPDs were >18 years old, and NK cells were identified as EBV-infected cell type in 54.8%. Nearly half of patients with EBV+ T/NK-LPDs had genetic defects associated with immunodeficiency. However, hemophagocytic lymphohistiocytosis, and not genetic defects, was the only parameter correlated with poor prognosis of EBV+ T/NK-LPDs. Conclusions Determination of EBV-infected cell types among PBMCs is a valuable tool for the differential diagnosis of EBV+ hematological diseases. In this study, determination of Epstein-Barr virus-infected cell types in peripheral blood mononuclear cells of 291 patients with high Epstein-Barr virus loads were retrospectively investigated, which indicate it is a valuable tool for Epstein-Barr virus-associated hematological diseases.

scholarly journals The BRRF1 Early Gene of Epstein-Barr Virus Encodes a Transcription Factor That Enhances Induction of Lytic Infection by BRLF1

2004 ◽  
Vol 78 (10) ◽  
pp. 4983-4992 ◽  
Author(s):  
Gregory K. Hong ◽  
Henri-Jacques Delecluse ◽  
Henri Gruffat ◽  
Thomas E. Morrison ◽  
Wen-Hai Feng ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Epstein Barr Virus ◽  
Cell Types ◽  
Early Gene ◽  
Barr Virus ◽  
Ebv Infection ◽  
Early Protein ◽  
293 Cells ◽  
Latently Infected ◽  
Epstein Barr

ABSTRACT The switch from the latent to the lytic form of Epstein-Barr virus (EBV) infection is mediated by expression of the viral immediate-early (IE) proteins, BZLF1 (Z) and BRLF1 (R). An EBV early protein, BRRF1 (Na), is encoded by the opposite strand of the BRLF1 intron, but the function of this nuclear protein in the viral life cycle is unknown. Here we demonstrate that Na enhances the R-mediated induction of lytic EBV infection in 293 cells latently infected with a recombinant EBV (R-KO) defective for the expression of both R and Na. Na also enhances R-induced lytic infections in a gastric carcinoma line (AGS) carrying the R-KO virus, although it has no effect in a Burkitt lymphoma line (BL-30) stably infected with the same mutant virus. We show that Na is a transcription factor that increases the ability of R to activate Z expression from the R-KO viral genome in 293 cells and that Na by itself activates the Z promoter (Zp) in EBV-negative cells. Na activation of Zp requires a CRE motif (ZII), and a consensus CRE motif is sufficient to transfer Na responsiveness to the heterologous E1b promoter. Furthermore, we show that Na enhances the transactivator function of a Gal4-c-Jun fusion protein but does not increase the transactivator function of other transcription factors (including ATF-1, ATF-2, and CREB) known to bind CRE motifs. Na expression in cells results in increased levels of a hyperphosphorylated form of c-Jun, suggesting a mechanism by which Na activates c-Jun. Our results indicate that Na is a transcription factor that activates the EBV Zp IE promoter through its effects on c-Jun and suggest that Na cooperates with BRLF1 to induce the lytic form of EBV infection in certain cell types.

scholarly journals Identification of Protein Tyrosine Kinases Required for B-Cell- Receptor-Mediated Activation of an Epstein-Barr Virus Immediate-Early Gene Promoter

2004 ◽  
Vol 78 (16) ◽  
pp. 8543-8551 ◽  
Author(s):  
Sandra Lavens ◽  
Emmanuel A. Faust ◽  
Fang Lu ◽  
Michele Jacob ◽  
Messele Leta ◽  
...  
Keyword(s):  
Signal Transduction ◽  
B Cell ◽  
Tyrosine Kinases ◽  
Epstein Barr Virus ◽  
Cell Receptor ◽  
Lytic Cycle ◽  
Protein Tyrosine Kinases ◽  
Early Gene ◽  
Barr Virus ◽  
Epstein Barr

ABSTRACT Epstein-Barr Virus (EBV) is a potentially oncogenic herpesvirus that infects >90% of the world's population. EBV exists predominantly as a latent infection in B lymphocytes, with periodic lytic-cycle reactivation essential for cellular and host transmission. Viral reactivation can be stimulated by ligand-induced activation of B-cell-receptor (BCR)-coupled signaling pathways. The critical first step in the transition from latency to the lytic cycle is the expression of the viral immediate-early gene BZLF1 through the transcription activation of its promoter, Zp. However, the BCR-coupled signal transduction cascade(s) leading to the induction of Zp and the expression of the BZLF1 gene product, Zta, is currently unclear. A major obstacle to delineating the relevant signal transduction events has been the lack of a model of EBV infection that is amenable to genetic manipulation. The use of the avian B-cell line DT40 has proven to be a powerful tool for delineating BCR-mediated signal transduction pathways that appear to be highly conserved between avian and mammalian systems. We demonstrate that the DT40 cell line is a robust and genetically tractable system for the study of BCR-mediated signaling pathways leading to transcriptional activation of BZLF1. Using this system, we demonstrate that activation of Zp requires the BCR-coupled protein tyrosine kinases Syk and Btk and that it is positively regulated by Lyn. Thus, the use of DT40 cells has allowed us to delineate the early signaling components required for BCR-dependent reactivation of latent EBV, and this system is likely to prove useful for further dissection of the downstream signaling cascades involved.

scholarly journals Complex Effects of Naturally Occurring Mutations in the JAK3 Pseudokinase Domain: Evidence for Interactions between the Kinase and Pseudokinase Domains

2000 ◽  
Vol 20 (3) ◽  
pp. 947-956 ◽  
Author(s):  
Min Chen ◽  
Alan Cheng ◽  
Fabio Candotti ◽  
Yong-Jie Zhou ◽  
Anka Hymel ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Tyrosine Kinases ◽  
Kinase Activity ◽  
Catalytic Domain ◽  
Intramolecular Interaction ◽  
Severe Combined Immunodeficiency ◽  
Kinase Domain ◽  
Barr Virus ◽  
Epstein Barr

ABSTRACT The structure of Janus kinases (JAKs) is unique among protein tyrosine kinases in having tandem, nonidentical kinase and pseudokinase domains. Despite its conservation in evolution, however, the function of the pseudokinase domain remains poorly understood. Lack of JAK3 expression results in severe combined immunodeficiency (SCID). In this study, we analyze two SCID patients with mutations in the JAK3 pseudokinase domain, which allows for protein expression but disrupts the regulation of the kinase activity. Specifically, these mutant forms of JAK3 had undetectable kinase activity in vitro but were hyperphosphorylated both in patients' Epstein-Barr virus-transformed B cells and when overexpressed in COS7 cells. Moreover, reconstitution of cells with these mutants demonstrated that, although they were constitutively phosphorylated basally, they were unable to transmit cytokine-dependent signals. Further analysis showed that the isolated catalytic domain of JAK3 was functional whereas either the addition of the pseudokinase domain or its deletion from the full-length molecule reduced catalytic activity. Through coimmunoprecipitation of the isolated pseudokinase domain with the isolated catalytic domain, we provide the first evidence that these two domains interact. Furthermore, whereas the wild-type pseudokinase domain modestly inhibited kinase domain-mediated STAT5 phosphorylation, the patient-derived mutants markedly inhibited this phosphorylation. We thus conclude that the JAK3 pseudokinase domain is essential for JAK3 function by regulating its catalytic activity and autophosphorylation. We propose a model in which this occurs via intramolecular interaction with the kinase domain and that increased inhibition of kinase activity by the pseudokinase domain likely contributes to the disease pathogenesis in these two patients.

scholarly journals A potent and protective human neutralizing antibody targeting a novel vulnerable site of Epstein-Barr virus

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qian-Ying Zhu ◽  
Sisi Shan ◽  
Jinfang Yu ◽  
Si-Ying Peng ◽  
Cong Sun ◽  
...  
Keyword(s):  
Epstein Barr Virus ◽  
Infected Individual ◽  
Neutralizing Antibody ◽  
Cell Types ◽  
Crystal Structure Analysis ◽  
Target Cells ◽  
High Dose ◽  
Barr Virus ◽  
Ebv Infection ◽  
Epstein Barr

AbstractEpstein-Barr virus (EBV) is associated with a range of epithelial and B cell malignancies as well as autoimmune disorders, for which there are still no specific treatments or effective vaccines. Here, we isolate EBV gH/gL-specific antibodies from an EBV-infected individual. One antibody, 1D8, efficiently neutralizes EBV infection of two major target cell types, B cells and epithelial cells. In humanized mice, 1D8 provides protection against a high-dose EBV challenge by substantially reducing viral loads and associated tumor burden. Crystal structure analysis reveals that 1D8 binds to a key vulnerable interface between the D-I/D-II domains of the viral gH/gL protein, especially the D-II of the gH, thereby interfering with the gH/gL-mediated membrane fusion and binding to target cells. Overall, we identify a potent and protective neutralizing antibody capable of reducing the EBV load. The novel vulnerable site represents an attractive target that is potentially important for antibody and vaccine intervention against EBV infection.

scholarly journals Molecular Evidence for Rhesus Lymphocryptovirus Infection of Epithelial Cells in Immunosuppressed Rhesus Macaques

2004 ◽  
Vol 78 (7) ◽  
pp. 3455-3461 ◽  
Author(s):  
Jeffery L. Kutok ◽  
Sherry Klumpp ◽  
Meredith Simon ◽  
John J. MacKey ◽  
Vuong Nguyen ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
B Cell ◽  
Rhesus Macaques ◽  
Molecular Evidence ◽  
Cell Infection ◽  
Barr Virus ◽  
Ebv Infection ◽  
Epstein Barr

ABSTRACT Epstein-Barr virus (EBV) is a human oncogenic herpesvirus associated with epithelial cell and B-cell malignancies. EBV infection of B lymphocytes is essential for acute and persistent EBV infection in humans; however, the role of epithelial cell infection in the normal EBV life cycle remains controversial. The rhesus lymphocryptovirus (LCV) is an EBV-related herpesvirus that naturally infects rhesus macaques and can be used experimentally to model persistent B-cell infection and B-cell lymphomagenesis. We now show that the rhesus LCV can infect epithelial cells in immunosuppressed rhesus macaques and can induce epithelial cell lesions resembling oral hairy leukoplakia in AIDS patients. Electron microscopy, immunohistochemistry, and DNA-RNA in situ hybridization were used to identify the presence of a lytic rhesus LCV infection in these proliferative, hyperkeratotic, or parakeratotic epithelial cell lesions. These studies demonstrate that the rhesus LCV has tropism for epithelial cells, in addition to B cells, and is a relevant animal model system for studying the role of epithelial cell infection in EBV pathogenesis.

scholarly journals Latent Membrane Protein 2A of Epstein-Barr Virus Binds WW Domain E3 Protein-Ubiquitin Ligases That Ubiquitinate B-Cell Tyrosine Kinases

2000 ◽  
Vol 20 (22) ◽  
pp. 8526-8535 ◽  
Author(s):  
Gösta Winberg ◽  
Liudmila Matskova ◽  
Fu Chen ◽  
Pamela Plant ◽  
Daniela Rotin ◽  
...  
Keyword(s):  
Membrane Protein ◽  
B Cell ◽  
Tyrosine Kinases ◽  
Epstein Barr Virus ◽  
Ubiquitin Ligases ◽  
Latent Membrane Protein ◽  
Ww Domains ◽  
Barr Virus ◽  
B Cell Signaling ◽  
Epstein Barr

ABSTRACT The latent membrane protein (LMP) 2A of Epstein-Barr virus (EBV) is implicated in the maintenance of viral latency and appears to function in part by inhibiting B-cell receptor (BCR) signaling. The N-terminal cytoplasmic region of LMP2A has multiple tyrosine residues that upon phosphorylation bind the SH2 domains of the Syk tyrosine kinase and the Src family kinase Lyn. The LMP2A N-terminal region also has two conserved PPPPY motifs. Here we show that the PPPPY motifs of LMP2A bind multiple WW domains of E3 protein-ubiquitin ligases of the Nedd4 family, including AIP4 and KIAA0439, and demonstrate that AIP4 and KIAA0439 form physiological complexes with LMP2A in EBV-positive B cells. In addition to a C2 domain and four WW domains, these proteins have a C-terminal Hect catalytic domain implicated in the ubiquitination of target proteins. LMP2A enhances Lyn and Syk ubiquitination in vivo in a fashion that depends on the activity of Nedd4 family members and correlates with destabilization of the Lyn tyrosine kinase. These results suggest that LMP2A serves as a molecular scaffold to recruit both B-cell tyrosine kinases and C2/WW/Hect domain E3 protein-ubiquitin ligases. This may promote Lyn and Syk ubiquitination in a fashion that contributes to a block in B-cell signaling. LMP2A may potentiate a normal mechanism by which Nedd4 family E3 enzymes regulate B-cell signaling.

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