scholarly journals Detection of EBV genomes in plasmablasts/plasma cells and non-B cells in the blood of most patients with EBV lymphoproliferative disorders by using Immuno-FISH

Blood ◽  
2010 ◽  
Vol 116 (22) ◽  
pp. 4546-4559 ◽  
Author(s):  
Sara Calattini ◽  
Irini Sereti ◽  
Philip Scheinberg ◽  
Hiroshi Kimura ◽  
Richard W. Childs ◽  
...  
Keyword(s):  
T Cells ◽  
B Cells ◽  
Copy Number ◽  
Plasma Cells ◽  
Cell Types ◽  
Cell Receptor ◽  
Lymphoproliferative Disorders ◽  
Prognostic Information ◽  
Barr Virus ◽  
Epstein Barr

Epstein-Barr virus (EBV) is present in B cells in the blood of healthy people; few studies have looked for EBV in other cell types in blood from patients with lymphoproliferative disorders. We use a new technique combining immunofluorescent cell-surface staining and fluorescent in situ hybridization to quantify both EBV copy number per cell and cell types in blood from patients with high EBV DNA loads. In addition to CD20+ B cells, EBV was present in plasmablast/plasma cells in the blood of 50% of patients, in monocytes or T cells in a small proportion of patients, and in “non-B, non-T, non-monocytes” in 69% of patients. The mean EBV copy number in B cells was significantly higher than in plasmablast/plasma cells. There was no correlation between EBV load and virus copy number per cell. Although we detected CD21, the EBV B-cell receptor, on EBV-infected B cells, we could not detect it on virus-infected T cells. These findings expand the range of cell types infected in the blood. Determining the number of EBV genomes per cell and the type of cells infected in patients with high EBV loads may provide additional prognostic information for the development of EBV lymphoproliferative diseases.

scholarly journals Functional Analysis of the CD4+ T-Cell Response to Epstein-Barr Virus: T-Cell-Mediated Activation of Resting B Cells and Induction of Viral BZLF1 Expression

2000 ◽  
Vol 74 (14) ◽  
pp. 6675-6679 ◽  
Author(s):  
Zheng Fu ◽  
Martin J. Cannon
Keyword(s):  
Functional Analysis ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Epstein Barr Virus ◽  
Lymphoproliferative Disorders ◽  
T Cell Response ◽  
Barr Virus ◽  
Epstein Barr

ABSTRACT In contrast to the major role played by Epstein-Barr virus (EBV)-specific CD8+ cytotoxic T-cell responses in immunosurveillance, recent studies have offered the apparently paradoxical suggestion that development of EBV-driven human B-cell lymphoproliferative disorders and tumors in SCID/hu mice is dependent on the presence of T cells, in particular CD4+ T cells. This study presents a functional analysis of the CD4+T-cell response to EBV and shows that while CD4+ T cells may be cytotoxic, they also express Th2 cytokines and CD40 ligand (gp39) and possess B-cell helper function. We show that EBV-specific CD4+ T cells can provide non-HLA-restricted help for activation of resting B cells via a gp39-CD40-dependent pathway and are able to induce expression of BZLF1, a viral lytic cycle transactivator in latently infected resting B cells, ultimately resulting in rapid outgrowth of transformed B-cell colonies. These results support the proposal that CD4+ T cells may play a key role in reactivation of latent EBV infection and may thus contribute to the pathogenesis of EBV-driven lymphoproliferative disorders.

scholarly journals Epstein-Barr Virus–induced Molecule 1 Ligand Chemokine Is Expressed by Dendritic Cells in Lymphoid Tissues and Strongly Attracts Naive T Cells and Activated B Cells

1998 ◽  
Vol 188 (1) ◽  
pp. 181-191 ◽  
Author(s):  
Vu N. Ngo ◽  
H. Lucy Tang ◽  
Jason G. Cyster
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
B Cells ◽  
Cd4 T Cells ◽  
Epstein Barr Virus ◽  
Cell Receptor ◽  
Lymphoid Tissues ◽  
Barr Virus ◽  
Epstein Barr ◽  
Activated B Cells

Movement of T and B lymphocytes through secondary lymphoid tissues is likely to involve multiple cues that help the cells navigate to appropriate compartments. Epstein-Barr virus– induced molecule 1 (EBI-1) ligand chemokine (ELC/MIP3β) is expressed constitutively within lymphoid tissues and may act as such a guidance cue. Here, we have isolated mouse ELC and characterized its expression pattern and chemotactic properties. ELC is expressed constitutively in dendritic cells within the T cell zone of secondary lymphoid tissues. Recombinant ELC was strongly chemotactic for naive (L-selectinhi) CD4 T cells and for CD8 T cells and weakly attractive for resting B cells and memory (L-selectinlo) CD4 T cells. After activation through the B cell receptor, the chemotactic response of B cells was enhanced. Like its human counterpart, murine ELC stimulated cells transfected with EBI-1/CC chemokine receptor 7 (CCR7). Our findings suggest a central role for ELC in promoting encounters between recirculating T cells and dendritic cells and in the migration of activated B cells into the T zone of secondary lymphoid tissues.

scholarly journals Targeting CAR to the Peptide-MHC Complex Reveals Distinct Signaling Compared to That of TCR in a Jurkat T Cell Model

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 867
Author(s):  
Ling Wu ◽  
Joanna Brzostek ◽  
Shvetha Sankaran ◽  
Qianru Wei ◽  
Jiawei Yap ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Model ◽  
Cell Receptor ◽  
Target Cells ◽  
Tcr Signaling ◽  
Barr Virus ◽  
Car T ◽  
Epstein Barr ◽  
Lower Magnitude

Chimeric antigen receptor T cells (CAR-T) utilize T cell receptor (TCR) signaling cascades and the recognition functions of antibodies. This allows T cells, normally restricted by the major histocompatibility complex (MHC), to be redirected to target cells by their surface antigens, such as tumor associated antigens (TAAs). CAR-T technology has achieved significant successes in treatment of certain cancers, primarily liquid cancers. Nonetheless, many challenges hinder development of this therapy, such as cytokine release syndrome (CRS) and the efficacy of CAR-T treatments for solid tumors. These challenges show our inadequate understanding of this technology, particularly regarding CAR signaling, which has been less studied. To dissect CAR signaling, we designed a CAR that targets an epitope from latent membrane protein 2 A (LMP2 A) of the Epstein–Barr virus (EBV) presented on HLA*A02:01. Because of this, CAR and TCR signaling can be compared directly, allowing us to study the involvement of other signaling molecules, such as coreceptors. This comparison revealed that CAR was sufficient to bind monomeric antigens due to its high affinity but required oligomeric antigens for its activation. CAR sustained the transduced signal significantly longer, but at a lower magnitude, than did TCR. CD8 coreceptor was recruited to the CAR synapse but played a negligible role in signaling, unlike for TCR signaling. The distinct CAR signaling processes could provide explanations for clinical behavior of CAR-T therapy and suggest ways to improve the technology.

scholarly journals Selective Induction of Th2-Attracting Chemokines CCL17 and CCL22 in Human B Cells by Latent Membrane Protein 1 of Epstein-Barr Virus

2004 ◽  
Vol 78 (4) ◽  
pp. 1665-1674 ◽  
Author(s):  
Takashi Nakayama ◽  
Kunio Hieshima ◽  
Daisuke Nagakubo ◽  
Emiko Sato ◽  
Masahiro Nakayama ◽  
...  
Keyword(s):  
T Cells ◽  
B Cells ◽  
Regulatory T Cells ◽  
Epstein Barr Virus ◽  
Cytotoxic T Cells ◽  
Th2 Cells ◽  
Th1 Cells ◽  
Barr Virus ◽  
Ebv Infection ◽  
Epstein Barr

ABSTRACT Chemokines are likely to play important roles in the pathophysiology of diseases associated with Epstein-Barr virus (EBV). Here, we have analyzed the repertoire of chemokines expressed by EBV-infected B cells. EBV infection of B cells induced expression of TARC/CCL17 and MDC/CCL22, which are known to attract Th2 cells and regulatory T cells via CCR4, and also upregulated constitutive expression of MIP-1α/CCL3, MIP-1β/CCL4, and RANTES/CCL5, which are known to attract Th1 cells and cytotoxic T cells via CCR5. Accordingly, EBV-immortalized B cells secreted these chemokines, especially CCL3, CCL4, and CCL22, in large quantities. EBV infection or stable expression of LMP1 also induced CCL17 and CCL22 in a B-cell line, BJAB. The inhibitors of the TRAF/NF-κB pathway (BAY11-7082) and the p38/ATF2 pathway (SB202190) selectively suppressed the expression of CCL17 and CCL22 in EBV-immortalized B cells and BJAB-LMP1. Consistently, transient-transfection assays using CCL22 promoter-reporter constructs demonstrated that two NF-κB sites and a single AP-1 site were involved in the activation of the CCL22 promoter by LMP1. Finally, serum CCL22 levels were significantly elevated in infectious mononucleosis. Collectively, LMP1 induces CCL17 and CCL22 in EBV-infected B cells via activation of NF-κB and probably ATF2. Production of CCL17 and CCL22, which attract Th2 and regulatory T cells, may help EBV-infected B cells evade immune surveillance by Th1 cells. However, the concomitant production of CCL3, CCL4, and CCL5 by EBV-infected B cells may eventually attract Th1 cells and cytotoxic T cells, leading to elimination of EBV-infected B cells at latency III and to selection of those with limited expression of latent genes.

scholarly journals Rewiring of B cell receptor signaling by Epstein–Barr virus LMP2A

2020 ◽  
Vol 117 (42) ◽  
pp. 26318-26327
Author(s):  
Kamonwan Fish ◽  
Federico Comoglio ◽  
Arthur L. Shaffer ◽  
Yanlong Ji ◽  
Kuan-Ting Pan ◽  
...  
Keyword(s):  
Cell Cycle ◽  
B Cells ◽  
B Cell ◽  
Epstein Barr Virus ◽  
Cell Receptor ◽  
B Cell Receptor ◽  
Barr Virus ◽  
Human B Cells ◽  
Bcr Signaling ◽  
Epstein Barr

Epstein–Barr virus (EBV) infects human B cells and reprograms them to allow virus replication and persistence. One key viral factor in this process is latent membrane protein 2A (LMP2A), which has been described as a B cell receptor (BCR) mimic promoting malignant transformation. However, how LMP2A signaling contributes to tumorigenesis remains elusive. By comparing LMP2A and BCR signaling in primary human B cells using phosphoproteomics and transcriptome profiling, we identified molecular mechanisms through which LMP2A affects B cell biology. Consistent with the literature, we found that LMP2A mimics a subset of BCR signaling events, including tyrosine phosphorylation of the kinase SYK, the calcium initiation complex consisting of BLNK, BTK, and PLCγ2, and its downstream transcription factor NFAT. However, the majority of LMP2A-induced signaling events markedly differed from those induced by BCR stimulation. These included differential phosphorylation of kinases, phosphatases, adaptor proteins, transcription factors such as nuclear factor κB (NF-κB) and TCF3, as well as widespread changes in the transcriptional output of LMP2A-expressing B cells. LMP2A affected apoptosis and cell-cycle checkpoints by dysregulating the expression of apoptosis regulators such as BCl-xL and the tumor suppressor retinoblastoma-associated protein 1 (RB1). LMP2A cooperated with MYC and mutant cyclin D3, two oncogenic drivers of Burkitt lymphoma, to promote proliferation and survival of primary human B cells by counteracting MYC-induced apoptosis and by inhibiting RB1 function, thereby promoting cell-cycle progression. Our results indicate that LMP2A is not a pure BCR mimic but rather rewires intracellular signaling in EBV-infected B cells that optimizes cell survival and proliferation, setting the stage for oncogenic transformation.

Transformation of BCR-deficient germinal-center B cells by EBV supports a major role of the virus in the pathogenesis of Hodgkin and posttransplantation lymphomas

Blood ◽  
2005 ◽  
Vol 106 (13) ◽  
pp. 4345-4350 ◽  
Author(s):  
Dörte Bechtel ◽  
Julia Kurth ◽  
Claus Unkel ◽  
Ralf Küppers
Keyword(s):  
B Cells ◽  
Cell Lines ◽  
Germinal Center ◽  
Somatic Hypermutation ◽  
Cell Receptor ◽  
Lymphoproliferative Disease ◽  
Barr Virus ◽  
Classic Hodgkin Lymphoma ◽  
Epstein Barr

In classic Hodgkin lymphoma (HL) and posttransplantation lymphoproliferative disease (PTLD), 2 malignancies frequently associated with Epstein-Barr virus (EBV), the tumor cells often appear to derive from B-cell receptor (BCR)–deficient and therefore preapoptotic germinal center (GC) B cells. To test whether EBV can rescue BCR-less GC B cells, we infected human tonsillar CD77+ GC B cells in vitro with EBV. More than 60 monoclonal lymphoblastoid cell lines (LCLs) were established. Among these, 28 cell lines did not express surface immunoglobulin (sIg). Two of the sIg-negative cell lines carry obviously destructive mutations that have been introduced into originally functional VH gene rearrangements during the process of somatic hypermutation. Quantitative reverse transcriptase–polymerase chain reaction (RT-PCR) showed that in most other lines the sIg deficiency was not simply the result of transcriptional down-regulation, but it was rather due to posttranscriptional defects. These findings strongly support the idea that EBV plays a central role in the pathogenesis of classic HL and PTLD by rescuing BCR-deficient, preapoptotic GC B cells from apoptosis, and that EBV infection renders the cells independent from survival signals normally supplied by a BCR. The monoclonal LCLs represent valuable models for early stages of lymphoma development in classic HL and PTLD.

scholarly journals Epstein-Barr Virus LMP2A Alters In Vivo and In Vitro Models of B-Cell Anergy, but Not Deletion, in Response to Autoantigen

2005 ◽  
Vol 79 (12) ◽  
pp. 7355-7362 ◽  
Author(s):  
Michelle A. Swanson-Mungerson ◽  
Robert G. Caldwell ◽  
Rebecca Bultema ◽  
Richard Longnecker
Keyword(s):  
B Cells ◽  
B Cell ◽  
Epstein Barr Virus ◽  
Nuclear Translocation ◽  
Cell Receptor ◽  
Barr Virus ◽  
Low Levels ◽  
Epstein Barr

ABSTRACT A significant percentage of the population latently harbors Epstein-Barr virus (EBV) in B cells. One EBV-encoded protein, latent membrane protein 2A (LMP2A), is expressed in tissue culture models of EBV latent infection, in human infections, and in many of the EBV-associated proliferative disorders. LMP2A constitutively activates proteins involved in the B-cell receptor (BCR) signal transduction cascade and inhibits the antigen-induced activation of these proteins. In the present study, we investigated whether LMP2A alters B-cell receptor signaling in primary B cells in vivo and in vitro. LMP2A does not inhibit antigen-induced tolerance in response to strong stimuli in an in vivo tolerance model in which B cells are reactive to self-antigen. In contrast, LMP2A bypasses anergy induction in response to low levels of soluble hen egg lysozyme (HEL) both in vivo and in vitro as determined by the ability of LMP2A-expressing HEL-specific B cells to proliferate and induce NF-κB nuclear translocation after exposure to low levels of antigen. Furthermore, LMP2A induces NF-κB nuclear translocation independent of BCR cross-linking. Since NF-κB is required to bypass tolerance induction, this LMP2A-dependent NF-κB activation may complete the tolerogenic signal induced by low levels of soluble HEL. Overall, the findings suggest that LMP2A may not inhibit BCR-induced signals under all conditions as previously suggested by studies with EBV immortalized B cells.

scholarly journals Infection Caused by Herpes Simplex Virus, Varicella-Zoster Virus and Epstein-Barr Virus in Organ Transplant Recipients, and their Diagnosis

1993 ◽  
Vol 4 (suppl c) ◽  
pp. 33-40
Author(s):  
F Diaz-Mitoma
Keyword(s):  
Herpes Simplex ◽  
B Cells ◽  
Epstein Barr Virus ◽  
Dna Amplification ◽  
Lymphoproliferative Disease ◽  
Lymphoproliferative Disorders ◽  
Diagnostic Methods ◽  
Transplant Recipients ◽  
Barr Virus ◽  
Epstein Barr

Immunosuppressed patients are at risk of severe herpesvirus infections. Herpes simplex (HSV), varicellazoster (VZV) and Epstein-Barr virus (EBV) infections are associated with characteristic syndromes in this population. Typically I-ISV and VZ:V infections cause mucocutaneous lesions; diagnosis is usually con finned by tissue culture or nuorescent microscopy. The availability of effective antiviral agents, and accurate techniques for laboratory diagnosis have improved the management of I-ISV and VZ:V infections. Antibody assays to demonstrate I-ISVorVZ:V infections are of limited value in immunocompromised patients, because the presence of antibodies does not indicate a decreased risk for HSV, varicella or zoster, but indicates susceptibility for reactivated infection. EBV is associated with lymphoproliferative disorders in transplant recipients. Infection of lymphocytes by EBV is a necessary step in achieving B cell transformation and immortalization. The lack of immunosurveillance against EBV-transformed B cells predisposes patients to developing invasive infiltration of transformed B cells . Diagnostic methods for EBV infections include lymphocyte transfom1ation, serology, and detection of DNA by direct hybridization or by DNA amplification. Quantitative oropharyngeal EBV shedding is a good marker for the development of lymphoproliferative disease in transplant recipients. Patients experiencing primary EBV infection are at the highest risk for lymphoproliferative disorders. Prophylactic antiviral therapy may be of benefit in preventing EBV replication and therefore in decreasing the risk for lymphoproliferation.

scholarly journals Calcium-dependent signalling in B-cell lymphomas

Oncogene ◽  
2021 ◽  
Author(s):  
Fedor Berditchevski ◽  
Eanna Fennell ◽  
Paul G. Murray
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Receptor ◽  
Receptor Activation ◽  
B Cell Receptor ◽  
Signalling Pathways ◽  
B Cell Lymphomas ◽  
Calcium Dependent ◽  
Barr Virus ◽  
Epstein Barr

AbstractInduced waves of calcium fluxes initiate multiple signalling pathways that play an important role in the differentiation and maturation of B-cells. Finely tuned transient Ca+2 fluxes from the endoplasmic reticulum in response to B-cell receptor (BCR) or chemokine receptor activation are followed by more sustained calcium influxes from the extracellular environment and contribute to the mechanisms responsible for the proliferation of B-cells, their migration within lymphoid organs and their differentiation. Dysregulation of these well-balanced mechanisms in B-cell lymphomas results in uncontrolled cell proliferation and resistance to apoptosis. Consequently, several cytotoxic drugs (and anti-proliferative compounds) used in standard chemotherapy regimens for the treatment of people with lymphoma target calcium-dependent pathways. Furthermore, ~10% of lymphoma associated mutations are found in genes with functions in calcium-dependent signalling, including those affecting B-cell receptor signalling pathways. In this review, we provide an overview of the Ca2+-dependent signalling network and outline the contribution of its key components to B cell lymphomagenesis. We also consider how the oncogenic Epstein-Barr virus, which is causally linked to the pathogenesis of a number of B-cell lymphomas, can modify Ca2+-dependent signalling.

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