CS16-6. Plasmacytoid Dendritic Cells are infected by Epstein Barr virus and induces TLR- dependent type I IFN production

ABSTRACT Epstein-Barr virus (EBV), a human herpesvirus, encodes 44 microRNAs (miRNAs), which regulate many genes with various functions in EBV-infected cells. Multiple target genes of the EBV miRNAs have been identified, some of which play important roles in adaptive antiviral immune responses. Using EBV mutant derivatives, we identified additional roles of viral miRNAs in governing versatile type I interferon (IFN) responses upon infection of human primary mature B cells. We also found that Epstein-Barr virus-encoded small RNAs (EBERs) and LF2, viral genes with previously reported functions in inducing or regulating IFN-I pathways, had negligible or even contrary effects on secreted IFN-α in our model. Data mining and Ago PAR-CLIP experiments uncovered more than a dozen previously uncharacterized, direct cellular targets of EBV miRNA associated with type I IFN pathways. We also identified indirect targets of EBV miRNAs in B cells, such as TRL7 and TLR9, in the prelatent phase of infection. The presence of epigenetically naive, non-CpG methylated viral DNA was essential to induce IFN-α secretion during EBV infection in a TLR9-dependent manner. In a newly established fusion assay, we verified that EBV virions enter a subset of plasmacytoid dendritic cells (pDCs) and determined that these infected pDCs are the primary producers of IFN-α in EBV-infected peripheral blood mononuclear cells. Our findings document that many EBV-encoded miRNAs regulate type I IFN response in newly EBV infected primary human B cells in the prelatent phase of infection and dampen the acute release of IFN-α in pDCs upon their encounter with EBV. IMPORTANCE Acute antiviral functions of all nucleated cells rely on type I interferon (IFN-I) pathways triggered upon viral infection. Host responses encompass the sensing of incoming viruses, the activation of specific transcription factors that induce the transcription of IFN-I genes, the secretion of different IFN-I types and their recognition by the heterodimeric IFN-α/β receptor, the subsequent activation of JAK/STAT signaling pathways, and, finally, the transcription of many IFN-stimulated genes (ISGs). In sum, these cellular functions establish a so-called antiviral state in infected and neighboring cells. To counteract these cellular defense mechanisms, viruses have evolved diverse strategies and encode gene products that target antiviral responses. Among such immune-evasive factors are viral microRNAs (miRNAs) that can interfere with host gene expression. We discovered that multiple miRNAs of Epstein-Barr virus (EBV) control over a dozen cellular genes that contribute to the antiviral states of immune cells, specifically B cells and plasmacytoid dendritic cells (pDCs). We identified the viral DNA genome as the activator of IFN-α and question the role of abundant EBV EBERs, that, contrary to previous reports, do not have an apparent inducing function in the IFN-I pathway early after infection.

Download Full-text

Multiple viral microRNAs regulate interferon release and signaling early during infection with Epstein-Barr virus

10.1101/2020.12.03.393306 ◽

2020 ◽

Author(s):

Mickaël Bouvet ◽

Stefanie Voigt ◽

Takanobu Tagawa ◽

Manuel Albanese ◽

Yen-Fu Adam Chen ◽

...

Keyword(s):

Dendritic Cells ◽

B Cells ◽

Epstein Barr Virus ◽

Type I Interferon ◽

Plasmacytoid Dendritic Cells ◽

Type I ◽

Viral Dna ◽

Barr Virus ◽

Epstein Barr ◽

Latent Phase

AbstractEpstein-Barr virus (EBV), a human herpes virus, encodes 44 microRNAs (miRNAs), which regulate many genes with various functions in EBV-infected cells. Multiple target genes of the EBV miRNAs have been identified, some of which play important roles in adaptive antiviral immune responses. Using EBV mutant derivatives, we identified additional roles of viral miRNAs in governing versatile type I interferon (IFN) responses upon infection of human primary mature B cells. We also found that Epstein-Barr virus-encoded small RNAs (EBERs) and LF2, viral genes with previously reported functions in inducing or regulating IFN-I pathways, had negligible or even contrary effects on secreted IFN-α in our model. Data mining and Ago PAR-CLIP experiments uncovered more than a dozen of previously uncharacterized, direct cellular targets of EBV miRNA associated with type I IFN pathways. We also identified indirect targets of EBV miRNAs in B cells, such as TRL7 and TLR9, in the pre-latent phase of infection. The presence of epigenetically naïve, non-CpG methylated viral DNA was essential to induce IFN-α secretion during EBV infection in a TLR9-dependent manner. In a newly established fusion assay, we verified that EBV virions enter a subset of plasmacytoid dendritic cells (pDCs) and determined that these infected pDCs are the primary producers of IFN-α in EBV-infected peripheral blood mononuclear cells. Our findings document that many EBV-encoded miRNAs regulate type I IFN response in newly EBV infected primary human B cells in the pre-latent phase of infection and dampen the acute release of IFN-α in pDCs upon their encounter with EBV.Author summaryAcute antiviral functions of all nucleated cells rely on type I interferon (IFN-I) pathways triggered upon viral infection. Host responses encompass the sensing of incoming viruses, the activation of specific transcription factors which induce transcription of IFN-I genes, the secretion of different IFN-I types and their recognition by the heterodimeric IFN-α/β receptor, the subsequent activation of JAK/STAT signaling pathways and, finally, the transcription of many IFN-stimulated genes (ISGs). In sum, these cellular functions establish a so-called antiviral state in infected and neighboring cells. To counteract these cellular defense mechanisms, viruses have evolved diverse strategies and encode gene products that target antiviral responses. Among such immune evasive factors are viral microRNAs (miRNAs) that can interfere with host gene expression. We discovered that multiple miRNAs encoded by Epstein-Barr virus (EBV) control over a dozen cellular genes that contribute to the anti-viral states of immune cells, specifically B cells and plasmacytoid dendritic cells (pDCs). We identified the viral DNA genome as the activator of IFN-α and question the role of abundant EBV EBERs, that, contrary to previous reports, do not have an apparent inducing function in the IFN-I pathway early after infection.

Download Full-text

Interferon Antagonism of Epstein–Barr Virus Tegument Proteins

Proceedings ◽

10.3390/proceedings2020050074 ◽

2020 ◽

Vol 50 (1) ◽

pp. 74

Author(s):

Wai-Yan Lui ◽

Sonia Jangra ◽

Kit-San Yuen ◽

Michael George Botelho ◽

Dong-Yan Jin

Keyword(s):

Epstein Barr Virus ◽

Tyrosine Phosphatase ◽

Host Cells ◽

Tegument Protein ◽

Small Subset ◽

Type I ◽

Type I Ifn ◽

Tegument Proteins ◽

Barr Virus ◽

Epstein Barr

The Epstein–Barr virus (EBV) successfully infects 95% of all adults but causes Burkitt’s lymphoma, Hodgkin’s lymphoma, gastric carcinoma, nasopharyngeal carcinoma or other malignancies in only a small subset of infected individuals. The virus must have developed effective viral countermeasures to evade host innate immunity. In this study, we performed functional screens to identify EBV-encoded interferon (IFN) antagonists. Several tegument proteins were found to be potent suppressors of IFN production and/or signaling. The large tegument protein and deubiquitinase BPLF1 antagonized type I IFN production induced by DNA sensors cGAS and STING or RNA sensors RIG-I and MAVS. BPLF1’s ability to suppress innate immune signaling required its deubiquitinase activity. BPLF1 functioned as a catalytically active deubiquitinase for both K63- and K48-linked ubiquitin chains on STING and TBK1, with no ubiquitin linkage specificity. Induced expression of BPLF1 in EBV-infected cells through CRISPRa led to effective suppression of innate DNA and RNA sensing. Another EBV tegument protein, BGLF2, was found to suppress JAK-STAT signaling. This suppression was ascribed to more pronounced K48-linked polyubiquitination and proteasomal degradation of BGLF2-associated STAT2. In addition, BGLF2 also recruited tyrosine phosphatase SHP1 to inhibit tyrosine phosphorylation of JAK1 and STAT1. A BGLF2-deficient EBV activated type I IFN signaling more robustly. Taken together, we characterized the IFN antagonism of EBV tegument proteins BPLF1 and BGLF2, which modulate ubiquitination of key transducer proteins to counteract type I IFN production and signaling in host cells. Supported by HMRF 17160822, HMRF 18170942, and RGC C7027-16G.

Download Full-text

Plasmacytoid dendritic cells respond to Epstein-Barr virus infection with a distinct type I interferon subtype profile

Blood Advances ◽

10.1182/bloodadvances.2018025536 ◽

2019 ◽

Vol 3 (7) ◽

pp. 1129-1144 ◽

Cited By ~ 6

Author(s):

Cornelia Gujer ◽

Anita Murer ◽

Anne Müller ◽

Danusia Vanoaica ◽

Kathrin Sutter ◽

...

Keyword(s):

Dendritic Cells ◽

T Cell ◽

Cell Expansion ◽

Epstein Barr Virus ◽

Cd8 T Cell ◽

Type I ◽

Barr Virus ◽

Ebv Infection ◽

Epstein Barr

Abstract Infectious mononucleosis, caused by infection with the human gamma-herpesvirus Epstein-Barr virus (EBV), manifests with one of the strongest CD8+ T-cell responses described in humans. The resulting T-cell memory response controls EBV infection asymptomatically in the vast majority of persistently infected individuals. Whether and how dendritic cells (DCs) contribute to the priming of this near-perfect immune control remains unclear. Here we show that of all the human DC subsets, plasmacytoid DCs (pDCs) play a central role in the detection of EBV infection in vitro and in mice with reconstituted human immune system components. pDCs respond to EBV by producing the interferon (IFN) subtypes α1, α2, α5, α7, α14, and α17. However, the virus curtails this type I IFN production with its latent EBV gene products EBNA3A and EBNA3C. The induced type I IFNs inhibit EBV entry and the proliferation of latently EBV-transformed B cells but do not influence lytic reactivation of the virus in vitro. In vivo, exogenous IFN-α14 and IFN-α17, as well as pDC expansion, delay EBV infection and the resulting CD8+ T-cell expansion, but pDC depletion does not significantly influence EBV infection. Thus, consistent with the observation that primary immunodeficiencies compromising type I IFN responses affect only alpha- and beta-herpesvirus infections, we found that EBV elicits pDC responses that transiently suppress viral replication and attenuate CD8+ T-cell expansion but are not required to control primary infection.

Download Full-text

Epstein-Barr virus promotes interferon-α production by plasmacytoid dendritic cells

Arthritis & Rheumatism ◽

10.1002/art.27408 ◽

2010 ◽

Vol 62 (6) ◽

pp. 1693-1701 ◽

Cited By ~ 52

Author(s):

Timothy E. Quan ◽

Robert M. Roman ◽

Benjamin J. Rudenga ◽

V. Michael Holers ◽

Joseph E. Craft

Keyword(s):

Dendritic Cells ◽

Epstein Barr Virus ◽

Plasmacytoid Dendritic Cells ◽

Interferon Α ◽

Barr Virus ◽

Epstein Barr

Download Full-text

Epstein–Barr virus and plasmacytoid dendritic cells: A possible duet in autoimmunity

Cytokine ◽

10.1016/j.cyto.2009.07.414 ◽

2009 ◽

Vol 48 (1-2) ◽

pp. 98-99

Author(s):

M. Severa ◽

B. Serafini ◽

V. Gafa ◽

E. Anastasiadou ◽

E. Giacomini ◽

...

Keyword(s):

Dendritic Cells ◽

Epstein Barr Virus ◽

Plasmacytoid Dendritic Cells ◽

Barr Virus ◽

Epstein Barr

Download Full-text

PLASMACYTOID DENDRITIC CELLS FUNCTION IN HIV INFECTION

Clinical & Investigative Medicine ◽

10.25011/cim.v31i4.4808 ◽

2008 ◽

Vol 31 (4) ◽

pp. 13

Author(s):

Martin Hyrcza ◽

Mario Ostrowski ◽

Sandy Der

Keyword(s):

Dendritic Cells ◽

Influenza Virus ◽

Hiv Infection ◽

Gene Transcription ◽

Sendai Virus ◽

Plasmacytoid Dendritic Cells ◽

Type I Interferons ◽

Interferon Response ◽

Type I ◽

Type I Ifn

Plasmacytoid dendritic cells (pDCs) are innate immune cells able to produce large quantities of type I interferons (IFN) when activated. Human immunodeficiency virus (HIV)-infected patients show generalized immune dysfunction characterized in part by chronic interferon response. In this study we investigated the role of dendritic cells inactivating and maintaining this response. Specifically we compared the IFN geneactivity in pDCs in response to several viruses and TLR agonists. We hypothesized that 1) the pattern of IFN gene transcription would differ in pDCs treated with HIV than with other agents, and 2) that pDCs from patients from different stages of disease would respond differently to the stimulations. To test these hypotheses, we obtained pDCs from 15 HIV-infected and uninfected individuals and treated freshly isolated pDCs with either HIV (BAL strain), influenza virus (A/PR/8/34), Sendai virus (Cantell strain), TLR7 agonist(imiquimod), or TLR9 agonist (CpG-ODN) for 6h. Type I IFN gene transcription was monitored by real time qPCRfor IFNA1, A2, A5, A6, A8,A17, B1, and E1, and cytokine levels were assayed by Cytometric Bead Arrays forTNF?, IL6, IL8, IL10, IL1?, and IL12p70. pDC function as determined by these two assays showed no difference between HIV-infected and uninfected patients or between patients with early or chronic infection. Specifically, HIV did notinduce type I IFN gene expression, whereas influenza virus, Sendai virus and imiquimod did. Similarly, HIV failed to induce any cytokine release from pDCs in contrast to influenza virus, Sendai virus and imiquimod, which stimulatedrelease of TNF?, IL6, or IL8. Together these results suggest that the reaction of pDCs to HIV virus is quantitatively different from the response to agents such as virus, Sendai virus, and imiquimod. In addition, pDCs from HIV-infected persons have responses similar to pDCs from uninfected donors, suggesting, that the DC function may not be affected by HIV infection.

Download Full-text

HCF1 and OCT2 Cooperate with EBNA1 To Enhance OriP-Dependent Transcription and Episome Maintenance of Latent Epstein-Barr Virus

Journal of Virology ◽

10.1128/jvi.00239-16 ◽

2016 ◽

Vol 90 (11) ◽

pp. 5353-5367 ◽

Cited By ~ 9

Author(s):

Jayaraju Dheekollu ◽

Andreas Wiedmer ◽

Daniel Sentana-Lledo ◽

Joel Cassel ◽

Troy Messick ◽

...

Keyword(s):

Transcription Factor ◽

Herpes Simplex Virus ◽

Herpes Simplex ◽

Epstein Barr Virus ◽

Histone H3 ◽

Type I ◽

Barr Virus ◽

Cellular Factors ◽

Epstein Barr ◽

Simplex Virus

ABSTRACTEpstein-Barr virus (EBV) establishes latent infections as multicopy episomes with complex patterns of viral gene transcription and chromatin structure. The EBV origin of plasmid replication (OriP) has been implicated as a critical control element for viral transcription, as well as viral DNA replication and episome maintenance. Here, we examine cellular factors that bind OriP and regulate histone modification, transcription regulation, and episome maintenance. We found that OriP is enriched for histone H3 lysine 4 (H3K4) methylation in multiple cell types and latency types. Host cell factor 1 (HCF1), a component of the mixed-lineage leukemia (MLL) histone methyltransferase complex, and transcription factor OCT2 (octamer-binding transcription factor 2) bound cooperatively with EBNA1 (Epstein-Barr virus nuclear antigen 1) at OriP. Depletion of OCT2 or HCF1 deregulated latency transcription and histone modifications at OriP, as well as the OriP-regulated latency type-dependent C promoter (Cp) and Q promoter (Qp). HCF1 depletion led to a loss of histone H3K4me3 (trimethylation of histone H3 at lysine 4) and H3 acetylation at Cp in type III latency and Qp in type I latency, as well as an increase in heterochromatic H3K9me3 at these sites. HCF1 depletion resulted in the loss of EBV episomes from Burkitt's lymphoma cells with type I latency and reactivation from lymphoblastoid cells (LCLs) with type III latency. These findings indicate that HCF1 and OCT2 function at OriP to regulate viral transcription, histone modifications, and episome maintenance. As HCF1 is best known for its function in herpes simplex virus 1 (HSV-1) immediate early gene transcription, our findings suggest that EBV latency transcription shares unexpected features with HSV gene regulation.IMPORTANCEEBV latency is associated with several human cancers. Viral latent cycle gene expression is regulated by the epigenetic control of the OriP enhancer region. Here, we show that cellular factors OCT2 and HCF1 bind OriP in association with EBNA1 to maintain elevated histone H3K4me3 and transcriptional enhancer function. HCF1 is known as a transcriptional coactivator of herpes simplex virus (HSV) immediate early (IE) transcription, suggesting that OriP enhancer shares aspects of HSV IE transcription control.

Download Full-text

Epstein-Barr Virus miR-BART6-3p Inhibits the RIG-I Pathway

Journal of Innate Immunity ◽

10.1159/000479749 ◽

2017 ◽

Vol 9 (6) ◽

pp. 574-586 ◽

Cited By ~ 33

Author(s):

Yuanjun Lu ◽

Zailong Qin ◽

Jia Wang ◽

Xiang Zheng ◽

Jianhong Lu ◽

...

Keyword(s):

Gene Expression ◽

Immune Response ◽

Epstein Barr Virus ◽

Type I ◽

Receptor Signaling ◽

Viral Pathogen ◽

Infection Period ◽

Barr Virus ◽

Ebv Infection ◽

Epstein Barr

Recognition of viral pathogen-associated molecular patterns by pattern recognition receptors (PRRs) is the first step in the initiation of a host innate immune response. As a PRR, RIG-I detects either viral RNA or replication transcripts. Avoiding RIG-I recognition is a strategy employed by viruses for immune evasion. Epstein-Barr virus (EBV) infects the majority of the human population worldwide. During the latent infection period there are only a few EBV proteins expressed, whereas EBV-encoded microRNAs, such as BART microRNAs, are highly expressed. BART microRNAs regulate both EBV and the host's gene expression, modulating virus proliferation and the immune response. Here, through gene expression profiling, we found that EBV miR-BART6-3ps inhibited genes of RIG-I-like receptor signaling and the type I interferon (IFN) response. We demonstrated that miR-BART6-3p rather than other BARTs specifically suppressed RIG-I-like receptor signaling-mediated IFN-β production. RNA-seq was used to analyze the global transcriptome change upon EBV infection and miR-BART6-3p mimics transfection, which revealed that EBV infection-triggered immune response signaling can be repressed by miR-BART6-3p overexpression. Furthermore, miR-BART6-3p inhibited the EBV-triggered IFN-β response and facilitated EBV infection through targeting the 3′UTR of RIG-I mRNA. These findings provide new insights into the mechanism underlying the strategies employed by EBV to evade immune surveillance.

Download Full-text