scholarly journals A Chaperone-Like Role for EBI3 in Collaboration With Calnexin Under Inflammatory Conditions

2021 ◽  
Vol 12 ◽  
Author(s):  
Aruma Watanabe ◽  
Izuru Mizoguchi ◽  
Hideaki Hasegawa ◽  
Yasuhiro Katahira ◽  
Shinya Inoue ◽  
...  
Keyword(s):  
Protein Level ◽  
Critical Role ◽  
Biologically Active ◽  
New Paradigm ◽  
Barr Virus ◽  
Adaptive Immune ◽  
Inflammatory Conditions ◽  
Target Molecules ◽  
Epstein Barr ◽  
Α Subunits

The interleukin-6 (IL-6)/IL-12 family of cytokines plays critical roles in the induction and regulation of innate and adaptive immune responses. Among the various cytokines, only this family has the unique characteristic of being composed of two distinct subunits, α- and β-subunits, which form a heterodimer with subunits that occur in other cytokines as well. Recently, we found a novel intracellular role for one of the α-subunits, Epstein-Barr virus-induced gene 3 (EBI3), in promoting the proper folding of target proteins and augmenting its expression at the protein level by binding to its target protein and a well-characterized lectin chaperone, calnexin, presumably through enhancing chaperone activity. Because calnexin is ubiquitously and constitutively expressed but EBI3 expression is inducible, these results could open an avenue to establish a new paradigm in which EBI3 plays an important role in further increasing the expression of target molecules at the protein level in collaboration with calnexin under inflammatory conditions. This theory well accounts for the heterodimer formation of EBI3 with p28, and probably with p35 and p19 to produce IL-27, IL-35, and IL-39, respectively. In line with this concept, another β-subunit, p40, plays a critical role in the assembly-induced proper folding of p35 and p19 to produce IL-12 and IL-23, respectively. Thus, chaperone-like activities in proper folding and maturation, which allow the secretion of biologically active heterodimeric cytokines, have recently been highlighted. This review summarizes the current understanding of chaperone-like activities of EBI3 to form heterodimers and other associations together with their possible biological implications.

scholarly journals Virus-specific CD4+ T cells: ready for direct attack

2006 ◽  
Vol 203 (4) ◽  
pp. 805-808 ◽  
Author(s):  
Kevin N. Heller ◽  
Cagan Gurer ◽  
Christian Münz
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Mhc Class Ii ◽  
Cd4 T Cells ◽  
Barr Virus ◽  
Adaptive Immune ◽  
Infected Cells ◽  
Efficient Processing ◽  
Epstein Barr ◽  
Direct Attack

CD4+ T cells are classically thought to orchestrate adaptive immune responses. But recent studies demonstrate that they can also kill infected cells directly. A new paper shows that highly efficient processing of Epstein Barr virus (EBV) glycoproteins for presentation on MHC class II makes virus-transformed B cells susceptible to lysis by CD4+ T cells. Thus, antiviral vaccines should aim to stimulate both helper and cytolytic CD4+ T cells.

scholarly journals Epstein-Barr Virus (EBV)-Encoded RNA 2 (EBER2) but Not EBER1 Plays a Critical Role in EBV-Induced B-Cell Growth Transformation

2007 ◽  
Vol 81 (20) ◽  
pp. 11236-11245 ◽  
Author(s):  
Yi Wu ◽  
Seiji Maruo ◽  
Misako Yajima ◽  
Teru Kanda ◽  
Kenzo Takada
Keyword(s):  
Cell Growth ◽  
B Cell ◽  
Epstein Barr Virus ◽  
Critical Role ◽  
Structural Similarity ◽  
Barr Virus ◽  
Growth Transformation ◽  
Latently Infected ◽  
Epstein Barr ◽  
Cell Densities

ABSTRACT Epstein-Barr virus (EBV)-encoded RNA 1 (EBER1) and EBER2 are untranslated RNAs and the most abundant viral transcripts in latently EBV-infected cells. We previously reported that EBERs play a critical role in efficient EBV-induced growth transformation of primary B cells. To investigate whether EBER1 and EBER2 have distinct roles in B-cell growth transformation, recombinant EBVs carrying either EBER1 or EBER2 were generated. The transforming ability of recombinant EBVs expressing EBER2 was as high as that of EBVs expressing both EBER1 and EBER2. In contrast, the transforming ability of recombinant EBVs carrying EBER1 was impaired and was similar to that of EBV lacking both EBER1 and EBER2. Lymphoblastoid cell lines (LCLs) established with EBVs carrying EBER2 proliferated at low cell densities, while LCLs established with EBVs carrying EBER1 did not. Interleukin 6 (IL-6) production in LCLs expressing EBER2 was more abundant than in those lacking EBER2. The growth of LCLs lacking EBER2 was enhanced by the addition of recombinant IL-6 to the cell culture, while the growth of EBER2-expressing LCLs was inhibited by a neutralizing anti-IL-6 antibody. These results demonstrate that EBER2, but not EBER1, contributes to efficient B-cell growth transformation. We conclude that EBER1 and EBER2, despite their structural similarity, have different functions in latently infected lymphoblastoid cells.

scholarly journals Epstein-Barr virus nuclear antigen 2 (EBNA2) extensively rewires the human chromatin landscape at autoimmune risk loci

2020 ◽  
Author(s):  
Ted Hong ◽  
Omer Donmez ◽  
Daniel Miller ◽  
Carmy Forney ◽  
Michael Lape ◽  
...  
Keyword(s):  
Autoimmune Diseases ◽  
Human Genome ◽  
Genetic Risk ◽  
Epstein Barr Virus ◽  
Critical Role ◽  
Chromatin Accessibility ◽  
Nuclear Antigen ◽  
Barr Virus ◽  
Chromatin Looping ◽  
Epstein Barr

AbstractThe interplay between environmental and genetic factors plays a key role in the development of many autoimmune diseases. In particular, the Epstein-Barr virus (EBV) is an established contributor to multiple sclerosis, lupus, and other disorders. Previously, we demonstrated that the EBV nuclear antigen 2 (EBNA2) transactivating protein occupies up to half of the risk loci for a set of seven autoimmune disorders. To further examine the mechanistic roles played by EBNA2 at these loci on genome-wide scale, we globally examined gene expression, chromatin accessibility, chromatin looping, and EBNA2 binding, in a B cell line that was 1) uninfected, 2) infected with a strain of EBV lacking EBNA2, or 3) infected with a strain that expresses EBNA2. We identified >400 EBNA2-dependent differentially expressed human genes and >4,000 EBNA2 binding events in the human genome. ATAC-seq analysis revealed >3,000 regions in the human genome with EBNA2-dependent chromatin accessibility, and HiChIP-seq data revealed >2,000 regions where EBNA2 altered chromatin looping interactions. Importantly, autoimmune genetic risk loci were highly enriched at the sites of these EBNA2-dependent chromatin-altering events. We present examples of autoimmune risk genotype-dependent EBNA2 events, nominating genetic risk mechanisms for autoimmune risk loci such as ZMIZ1 and CD80. Taken together, our results reveal important interactions between host genetic variation and EBNA2-driven disease mechanisms. Further, our study highlights a critical role for EBNA2 in rewiring human gene regulatory programs through rearrangement of the chromatin landscape and nominates these interactions as components of genetic mechanisms that influence the risk of multiple autoimmune diseases.

scholarly journals Interleukin-12p35 Deficiency Reverses the Th1/Th2 Imbalance, Aggravates the Th17/Treg Imbalance, and Ameliorates Atherosclerosis in ApoE-/- Mice

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Ying Huang ◽  
Haiying Hu ◽  
Ling Liu ◽  
Jing Ye ◽  
Zhen Wang ◽  
...  
Keyword(s):  
T Cells ◽  
Epstein Barr Virus ◽  
Critical Role ◽  
Plaque Formation ◽  
Barr Virus ◽  
Atherosclerotic Lesions ◽  
Atherosclerotic Plaque Formation ◽  
Epstein Barr ◽  
Deficient Mice ◽  
Recombinant Mice

Interleukin- (IL-) 35, a novel functional cytokine of regulatory T cells (Treg) comprised of the IL-12p35 subunit and the other subunit Epstein-Barr virus-induced gene 3 (EBI3), regulates the activity of CD4+ T cells and macrophages, thereby playing a critical role in inflammatory and autoimmune diseases. Previous studies demonstrated that both recombinant mice and human IL-35 attenuated atherosclerosis in ApoE-/- mice. Additionally, EBI3 deficiency enhanced the activation of macrophages and increased atherosclerotic lesions in LDLR-/- mice. This study generated double-deficient mice for ApoE and IL-12p35 (ApoE-/- IL-12p35-/- mice) and investigated the effect of IL-12p35 deficiency on atherosclerosis. IL-12p35 deficiency alleviated Th1/Th2 imbalance, aggravated Th17/Treg imbalance, and attenuated atherosclerotic plaque formation in ApoE-/- mice. Additionally, exogenous rIL-35 treatment reversed the imbalance of Th17/Treg and attenuated atherosclerosis in ApoE-/- mice. These findings suggest that IL-12p35 deficiency ameliorates atherosclerosis in ApoE-/- mice, partially, via attenuating the Th1/Th2 imbalance, although IL-12p35 deficiency aggravates the Th17/Treg imbalance.

scholarly journals Epstein-Barr Virus-Induced Epigenetic Pathogenesis of Viral-Associated Lymphoepithelioma-Like Carcinomas and Natural Killer/T-Cell Lymphomas

Pathogens ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 63 ◽  
Author(s):  
Lili Li ◽  
Brigette Ma ◽  
Anthony Chan ◽  
Francis Chan ◽  
Paul Murray ◽  
...  
Keyword(s):  
T Cell ◽  
Natural Killer ◽  
Epstein Barr Virus ◽  
Critical Role ◽  
Epigenetic Alterations ◽  
Barr Virus ◽  
Genome Wide ◽  
Epigenetic Machinery ◽  
Epstein Barr ◽  
Associated Tumors

Cancer genome studies of Epstein-Barr virus (EBV)-associated tumors, including lymphoepithelioma-like carcinomas (LELC) of nasopharyngeal (NPC), gastric (EBVaGC) and lung tissues, and natural killer (NK)/T-cell lymphoma (NKTCL), reveal a unique feature of genomic alterations with fewer gene mutations detected than other common cancers. It is known now that epigenetic alterations play a critical role in the pathogenesis of EBV-associated tumors. As an oncogenic virus, EBV establishes its latent and lytic infections in B-lymphoid and epithelial cells, utilizing hijacked cellular epigenetic machinery. EBV-encoded oncoproteins modulate cellular epigenetic machinery to reprogram viral and host epigenomes, especially in the early stage of infection, using host epigenetic regulators. The genome-wide epigenetic alterations further inactivate a series of tumor suppressor genes (TSG) and disrupt key cellular signaling pathways, contributing to EBV-associated cancer initiation and progression. Profiling of genome-wide CpG methylation changes (CpG methylome) have revealed a unique epigenotype of global high-grade methylation of TSGs in EBV-associated tumors. Here, we have summarized recent advances of epigenetic alterations in EBV-associated tumors (LELCs and NKTCL), highlighting the importance of epigenetic etiology in EBV-associated tumorigenesis. Epigenetic study of these EBV-associated tumors will discover valuable biomarkers for their early detection and prognosis prediction, and also develop effective epigenetic therapeutics for these cancers.

scholarly journals Nuclear Factor-κB Binds to the Epstein-Barr Virus LMP1 Promoter and Upregulates Its Expression

2008 ◽  
Vol 83 (3) ◽  
pp. 1393-1401 ◽  
Author(s):  
Pegah Johansson ◽  
Ann Jansson ◽  
Ulla Rüetschi ◽  
Lars Rymo
Keyword(s):  
B Cells ◽  
Epstein Barr Virus ◽  
Affinity Purification ◽  
Critical Role ◽  
Mobility Shift ◽  
Barr Virus ◽  
Exogenous Expression ◽  
Epstein Barr

ABSTRACT The latent membrane protein 1 (LMP1) oncogene carried by Epstein-Barr virus (EBV) is essential for transformation and maintenance of EBV-immortalized B cells in vitro, and it is expressed in most EBV-associated tumor types. The activation of the NF-κB pathway by LMP1 plays a critical role in the upregulation of antiapoptotic proteins. The EBV-encoded EBNA2 transactivator is required for LMP1 activation in latency III, while LMP1 itself appears to be critical for its activation in the latency II gene expression program. In both cases, additional viral and cellular transcription factors are required in mediating transcription activation of the LMP1 promoter. Using DNA affinity purification and chromatin immunoprecipitation assay, we showed here that members of the NF-κB transcription factor family bound to the LMP1 promoter in vitro and in vivo. Electrophoretic mobility shift assay analyses indicated the binding of the p50-p50 homodimer and the p65-p50 heterodimer to an NF-κB site in the LMP1 promoter. Transient transfections and reporter assays showed that the LMP1 promoter is activated by exogenous expression of NF-κB factors in both B cells and epithelial cells. Exogenous expression of NF-κB factors in the EBNA2-deficient P3HR1 cell line induced LMP1 protein expression. Overall, our data are consistent with the presence of a positive regulatory circuit between NF-κB activation and LMP1 expression.

scholarly journals HSP70-Homolog DnaK of Pseudomonas aeruginosa Increases the Production of IL-27 through Expression of EBI3 via TLR4-Dependent NF-κB and TLR4-Independent Akt Signaling

2020 ◽  
Vol 21 (23) ◽  
pp. 9194
Author(s):  
Jisu Jeon ◽  
Yeji Lee ◽  
Hyeonseung Yu ◽  
Un-Hwan Ha
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Signaling Pathways ◽  
Inflammatory Responses ◽  
Akt Signaling ◽  
Biologically Active ◽  
Akt Signaling Pathway ◽  
Barr Virus ◽  
Pseudomonas Aeruginosa Infection ◽  
Epstein Barr ◽  
Anti Inflammatory Cytokine

IL-27, a heterodimeric cytokine composed of the p28 subunit and Epstein–Barr virus-induced gene 3 (EBI3), acts as a potent immunosuppressant and thus limits pathogenic inflammatory responses. IL-27 is upregulated upon Pseudomonas aeruginosa infection in septic mice, increasing susceptibility to the infection and decreasing clearance of the pathogen. However, it remains unclear which P. aeruginosa-derived molecules promote production of IL-27. In this study, we explored the mechanism by which P. aeruginosa DnaK, a heat shock protein 70-like protein, induces EBI3 expression, thereby promoting production of IL-27. Upregulation of EBI3 expression did not lead to an increase in IL-35, which consists of the p35 subunit and EBI3. The IL-27 production in response to DnaK was biologically active, as reflected by stimulation of IL-10 production. DnaK-mediated expression of EBI3 was driven by two distinct signaling pathways, NF-κB and Akt. However, NF-κB is linked to TLR4-associated signaling pathways, whereas Akt is not. Taken together, our results reveal that P. aeruginosa DnaK potently upregulates EBI3 expression, which in turn drives production of the prominent anti-inflammatory cytokine IL-27, as a consequence of TLR4-dependent activation of NF-κB and TLR4-independent activation of the Akt signaling pathway.

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