High Secretion of Interferons by Human Plasmacytoid Dendritic Cells upon Recognition of Middle East Respiratory Syndrome Coronavirus

ABSTRACTThe Middle East respiratory syndrome coronavirus (MERS-CoV) emerged in 2012 as the causative agent of a severe respiratory disease with a fatality rate of approximately 30%. The high virulence and mortality rate prompted us to analyze aspects of MERS-CoV pathogenesis, especially its interaction with innate immune cells such as antigen-presenting cells (APCs). Particularly, we analyzed secretion of type I and type III interferons (IFNs) by APCs, i.e., B cells, macrophages, monocyte-derived/myeloid dendritic cells (MDDCs/mDCs), and by plasmacytoid dendritic cells (pDCs) of human and murine origin after inoculation with MERS-CoV. Production of large amounts of type I and III IFNs was induced exclusively in human pDCs, which were significantly higher than IFN induction by severe acute respiratory syndrome (SARS)-CoV. Of note, IFNs were secreted in the absence of productive replication. However, receptor binding, endosomal uptake, and probably signaling via Toll-like receptor 7 (TLR7) were critical for sensing of MERS-CoV by pDCs. Furthermore, active transcription of MERS-CoV N RNA and subsequent N protein expression were evident in infected pDCs, indicating abortive infection. Taken together, our results point toward dipeptidyl peptidase 4 (DPP4)-dependent endosomal uptake and subsequent infection of human pDCs by MERS-CoV. However, the replication cycle is stopped after early gene expression. In parallel, human pDCs are potent IFN-producing cells upon MERS-CoV infection. Knowledge of such IFN responses supports our understanding of MERS-CoV pathogenesis and is critical for the choice of treatment options.IMPORTANCEMERS-CoV causes a severe respiratory disease with high fatality rates in human patients. Recently, confirmed human cases have increased dramatically in both number and geographic distribution. Understanding the pathogenesis of this highly pathogenic CoV is crucial for developing successful treatment strategies. This study elucidates the interaction of MERS-CoV with APCs and pDCs, particularly the induction of type I and III IFN secretion. Human pDCs are the immune cell population sensing MERS-CoV but secrete significantly larger amounts of IFNs, especially IFN-α, than in response to SARS-CoV. A model for molecular virus-host interactions is presented outlining IFN induction in pDCs. The massive IFN secretion upon contact suggests a critical role of this mechanism for the high degree of immune activation observed during MERS-CoV infection.

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Alphaherpesvirus-induced activation of plasmacytoid dendritic cells depends on the viral glycoprotein gD and is inhibited by non-infectious light particles

PLoS Pathogens ◽

10.1371/journal.ppat.1010117 ◽

2021 ◽

Vol 17 (11) ◽

pp. e1010117

Author(s):

Jonas L. Delva ◽

Cliff Van Waesberghe ◽

Barbara G. Klupp ◽

Thomas C. Mettenleiter ◽

Herman W. Favoreel

Keyword(s):

Dendritic Cells ◽

Pseudorabies Virus ◽

Viral Infections ◽

Critical Role ◽

Plasmacytoid Dendritic Cells ◽

Type I ◽

Viral Glycoprotein ◽

Dna Viruses ◽

Endosomal Acidification ◽

Simplex Virus

Plasmacytoid dendritic cells (pDC) are important innate immune cells during the onset of viral infections as they are specialized in the production of massive amounts of antiviral type I interferon (IFN). Alphaherpesviruses such as herpes simplex virus (HSV) or pseudorabies virus (PRV) are double stranded DNA viruses and potent stimulators of pDC. Detailed information on how PRV activates porcine pDC is lacking. Using PRV and porcine primary pDC, we report here that PRV virions, so-called heavy (H-)particles, trigger IFNα production by pDC, whereas light (L-) particles that lack viral DNA and capsid do not. Activation of pDC requires endosomal acidification and, importantly, depends on the PRV gD envelope glycoprotein and O-glycosylations. Intriguingly, both for PRV and HSV-1, we found that L-particles suppress H-particle-mediated activation of pDC, a process which again depends on viral gD. This is the first report describing that gD plays a critical role in alphaherpesvirus-induced pDC activation and that L-particles directly interfere with alphaherpesvirus-induced IFNα production by pDC.

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A type I IFN–Flt3 ligand axis augments plasmacytoid dendritic cell development from common lymphoid progenitors

Journal of Experimental Medicine ◽

10.1084/jem.20130536 ◽

2013 ◽

Vol 210 (12) ◽

pp. 2515-2522 ◽

Cited By ~ 33

Author(s):

Yi-Ling Chen ◽

Ting-Ting Chen ◽

Li-Mei Pai ◽

Joanna Wesoly ◽

Hans A.R. Bluyssen ◽

...

Keyword(s):

Dendritic Cells ◽

Dendritic Cell ◽

Type I Interferon ◽

Plasmacytoid Dendritic Cell ◽

Critical Role ◽

Plasmacytoid Dendritic Cells ◽

Type I ◽

Type I Ifn ◽

Flt3 Ligand ◽

Lymphoid Progenitors

During infections and inflammation, plasmacytoid dendritic cells (pDCs) are the most potent type I interferon (IFN-I)–producing cells. However, the developmental origin of pDCs and the signals dictating pDC generation remain incompletely understood. Here, we report a synergistic role for IFN-I and Flt3 ligand (FL) in pDC development from common lymphoid progenitors (CLPs). Both conventional DCs (cDCs) and pDCs were generated from CLPs in response to FL, whereas pDC generation required higher concentrations of FL and concurrent IFN-I signaling. An absence of IFN-I receptor, impairment of IFN-I signaling, or neutralization of IFN-I significantly impeded pDC development from CLPs. Furthermore, FL induced IFN-I expression in CLPs, which in turn induced Flt3 up-regulation that facilitated survival and proliferation of CLPs, as well as their differentiation into pDCs. Collectively, these results define a critical role for the FL/IFN-I/Flt3 axis in pDC differentiation from CLPs.

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AB0034 PD-1 AGONISM INHIBITS ACTIVATION OF PLASMACYTOID DENDRITIC CELLS

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2021-eular.2682 ◽

2021 ◽

Vol 80 (Suppl 1) ◽

pp. 1050.1-1050

Author(s):

I. Banerjee ◽

L. Edwards ◽

P. Halvey ◽

S. Alioto ◽

D. Cluckley ◽

...

Keyword(s):

Dendritic Cells ◽

Immune Cell ◽

Plasmacytoid Dendritic Cells ◽

Clinical Aspects ◽

Immune Homeostasis ◽

Type I ◽

Immunoglobulin Gene ◽

Human Pbmcs ◽

Type I Ifn ◽

The Impact

Background:T cell function is regulated by complex signaling networks of interconnected activators and inhibitors. Blockade of inhibitory receptors such as programmed death-1 (PD-1) has emerged as a novel treatment for multiple forms of cancer. One of the most common adverse events associated with blockade of the endogenous PD-1/PD-L1 pathway is the induction of autoimmune pathology in multiple tissues, demonstrating that PD-1 activation is necessary for normal immune homeostasis in humans (Kostine, et al., 2018). Given this body of clinical data, we sought to develop a PD-1 agonist antibody as a therapeutic approach to restore immune homeostasis in patients living with autoimmune diseases. PD-1 expression and function has been primarily described on T cells (Ishida, et al., 1992), with additional data available from several other immune cell populations (Ohaegbulam, et al., 2015).Objectives:To study the effect of PD-1 agonism on plasmacytoid dendritic cell (pDC) function.Methods:Human PBMCs stimulated with or without toll-like receptor (TLR)-9 agonist, CpG were analyzed by flow cytometry for PD-1 expression on immune cell subsets. To assess the impact of PD-1 agonist on pDC function human PBMCs were activated by CpG in the presence or absence of PD-1 agonist. Type-I interferon (IFN) levels were quantified using ELISA from culture supernatants. The expression of interferon stimulated genes was analyzed by qPCR as a measure of type-I IFN activation.Results:We have discovered that TLR9 activation can induce PD-1 expression on plasmacytoid dendritic cells, which has not been previously reported. Further, we have demonstrated that PD-1 agonism inhibits TLR9-mediated activation and the effector functions of plasmacytoid dendritic cells.Conclusion:These data suggest the potential of PD-1 as a target for regulating diseases with pathology generated by type-I IFN.References:[1]Ishida, Y., Agata, Y., Shihibahara, K., & Honjo, T. (1992). Induced expression of PD-1, a novel member of the immunoglobulin gene superfamily, upon programmed cell death. EMBO J., 11(11):3887-95.[2]Kostine, M., Rouxel, L., Barnetche, T., Veillon, R., Martin, F., Dutriaux, C., . . . Schaeverbeke, T. (2018). Rheumatic disorders associated with immune checkpoint inhibitors in patients with cancer-clinical aspects and relationship with tumour response: a single-centre prospective cohort study. Annual Rheumatic Disease, 77(3):393-398.[3]Ohaegbulam, K. C., Assal, A., Lazar-Molnar, E., Yao, Y., & Zang, X. (2015). Human cancer immunotherapy with antibodies to the PD-1 and PD-L1 pathway. Trends in Molecular Medicine, 21(1); 24-33.Disclosure of Interests:Ishita Banerjee Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Lindsay Edwards Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Patrick Halvey Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Salvatore Alioto Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, David Cluckley Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Caitlin Mitchell Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Christopher Cox Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Emily Lurier Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Michael Cianci Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Soumya Bengeri Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Susmita Borthakur Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Katalin Kis-Toth Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Nathan Higginson-Scott Shareholder of: Pandion Therapeutics, Consultant of: Biotech Companies, Employee of: Pandion Therapeutics, Jo Viney Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Kevin L. Otipoby Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics

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Plasmacytoid dendritic cells produce type I interferon and reduce viral replication in airway epithelial cells after SARS-CoV-2 infection

10.1101/2021.05.12.443948 ◽

2021 ◽

Author(s):

Luisa Cervantes-Barragan ◽

Abigail Vanderheiden ◽

Charlotte J Royer ◽

Meredith E Davis-Gardner ◽

Philipp Ralfs ◽

...

Keyword(s):

Dendritic Cells ◽

Epithelial Cells ◽

Viral Replication ◽

Immune Cell ◽

Type I Interferon ◽

Airway Epithelial Cells ◽

Plasmacytoid Dendritic Cells ◽

Type I ◽

Airway Epithelial ◽

Type I Ifn

Infection with SARS-CoV-2 has caused a pandemic of unprecedented dimensions. SARS-CoV-2 infects airway and lung cells causing viral pneumonia. The importance of type I interferon (IFN) production for the control of SARS-CoV-2 infection is highlighted by the increased severity of COVID-19 in patients with inborn errors of type I IFN response or auto-antibodies against IFN-α. Plasmacytoid dendritic cells (pDCs) are a unique immune cell population specialized in recognizing and controlling viral infections through the production of high concentrations of type I IFN. In this study, we isolated pDCs from healthy donors and showed that pDCs are able to recognize SARS-CoV-2 and rapidly produce large amounts of type I IFN. Sensing of SARS-CoV-2 by pDCs was independent of viral replication since pDCs were also able to recognize UV-inactivated SARS-CoV-2 and produce type I IFN. Transcriptional profiling of SARS-CoV-2 and UV-SARS-CoV-2 stimulated pDCs also showed a rapid type I and III IFN response as well as induction of several chemokines, and the induction of apoptosis in pDCs. Moreover, we modeled SARS-CoV-2 infection in the lung using primary human airway epithelial cells (pHAEs) and showed that co-culture of pDCs with SARS-CoV-2 infected pHAEs induces an antiviral response and upregulation of antigen presentation in pHAE cells. Importantly, the presence of pDCs in the co-culture results in control of SARS-CoV-2 replication in pHAEs. Our study identifies pDCs as one of the key cells that can recognize SARS-CoV-2 infection, produce type I and III IFN and control viral replication in infected cells.

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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.

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Faculty Opinions recommendation of Toll-like receptor-mediated induction of type I interferon in plasmacytoid dendritic cells requires the rapamycin-sensitive PI(3)K-mTOR-p70S6K pathway.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1123432.582895 ◽

2008 ◽

Author(s):

Adolfo Garcia-Sastre

Keyword(s):

Dendritic Cells ◽

Type I Interferon ◽

Plasmacytoid Dendritic Cells ◽

Type I ◽

Toll Like Receptor

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Human plasmacytoid dendritic cells mount a distinct antiviral response to virus-infected cells

Science Immunology ◽

10.1126/sciimmunol.abc7302 ◽

2021 ◽

Vol 6 (58) ◽

pp. eabc7302

Author(s):

Tae Jin Yun ◽

Suzu Igarashi ◽

Haoquan Zhao ◽

Oriana A. Perez ◽

Marcus R. Pereira ◽

...

Keyword(s):

Dendritic Cells ◽

Virus Detection ◽

Plasmacytoid Dendritic Cells ◽

Lung Epithelial Cells ◽

Live Cells ◽

Type I ◽

Antiviral Immune Response ◽

Lung Epithelial ◽

Functional Consequences ◽

Infected Cells

Plasmacytoid dendritic cells (pDCs) can rapidly produce interferons and other soluble factors in response to extracellular viruses or virus mimics such as CpG-containing DNA. pDCs can also recognize live cells infected with certain RNA viruses, but the relevance and functional consequences of such recognition remain unclear. We studied the response of primary DCs to the prototypical persistent DNA virus, human cytomegalovirus (CMV). Human pDCs produced high amounts of type I interferon (IFN-I) when incubated with live CMV-infected fibroblasts but not with free CMV; the response involved integrin-mediated adhesion, transfer of DNA-containing virions to pDCs, and the recognition of DNA through TLR9. Compared with transient polyfunctional responses to CpG or free influenza virus, pDC response to CMV-infected cells was long-lasting, dominated by the production of IFN-I and IFN-III, and lacked diversification into functionally distinct populations. Similarly, pDC activation by influenza-infected lung epithelial cells was highly efficient, prolonged, and dominated by interferon production. Prolonged pDC activation by CMV-infected cells facilitated the activation of natural killer cells critical for CMV control. Last, patients with CMV viremia harbored phenotypically activated pDCs and increased circulating IFN-I and IFN-III. Thus, recognition of live infected cells is a mechanism of virus detection by pDCs that elicits a unique antiviral immune response.

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Lymphocytoid Choriomeningitis Virus Activates Plasmacytoid Dendritic Cells and Induces a Cytotoxic T-Cell Response via MyD88

Journal of Virology ◽

10.1128/jvi.01640-07 ◽

2007 ◽

Vol 82 (1) ◽

pp. 196-206 ◽

Cited By ~ 92

Author(s):

Andreas Jung ◽

Hiroki Kato ◽

Yutaro Kumagai ◽

Himanshu Kumar ◽

Taro Kawai ◽

...

Keyword(s):

Dendritic Cells ◽

Intracellular Signaling ◽

Plasmacytoid Dendritic Cells ◽

T Cell Response ◽

Cytotoxic T Cell ◽

Type I ◽

Ctl Response ◽

Type I Ifns ◽

Lcmv Infection

ABSTRACTToll-like receptors (TLRs) and retinoic acid-inducible gene I-like helicases (RLHs) are two major machineries recognizing RNA virus infection of innate immune cells. Intracellular signaling for TLRs and RLHs is mediated by their cytoplasmic adaptors, i.e., MyD88 or TRIF and IPS-1, respectively. In the present study, we investigated the contributions of TLRs and RLHs to the cytotoxic T-lymphocyte (CTL) response by using lymphocytoid choriomeningitis virus (LCMV) as a model virus. The generation of virus-specific cytotoxic T lymphocytes was critically dependent on MyD88 but not on IPS-1. Type I interferons (IFNs) are known to be important for the development of the CTL response to LCMV infection. Serum levels of type I IFNs and proinflammatory cytokines were mainly dependent on the presence of MyD88, although IPS-1−/−mice showed a decrease in IFN-α levels but not in IFN-β and proinflammatory cytokine levels. Analysis ofIfna6+/GFPreporter mice revealed that plasmacytoid dendritic cells (DCs) are the major source of IFN-α in LCMV infection. MyD88−/−mice were highly susceptible to LCMV infection in vivo. These results suggest that recognition of LCMV by plasmacytoid DCs via TLRs is responsible for the production of type I IFNs in vivo. Furthermore, the activation of a MyD88-dependent innate mechanism induces a CTL response, which eventually leads to virus elimination.

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