scholarly journals Plasmacytoid Dendritic Cells Depletion and Elevation of IFN-γ Dependent Chemokines CXCL9 and CXCL10 in Children With Multisystem Inflammatory Syndrome

2021 ◽  
Vol 12 ◽  
Author(s):  
Francesca Caldarale ◽  
Mauro Giacomelli ◽  
Emirena Garrafa ◽  
Nicola Tamassia ◽  
Alessia Morreale ◽  
...  
Keyword(s):  
Immune Response ◽  
Dendritic Cells ◽  
Clinical Manifestations ◽  
Plasmacytoid Dendritic Cells ◽  
Type I ◽  
Reactive Protein ◽  
Cardiovascular Damage ◽  
Inflammatory Chemokines ◽  
Ifn Γ ◽  
Inflammatory Syndrome

BackgroundSARS-CoV-2 occurs in the majority of children as COVID-19, without symptoms or with a paucisymptomatic respiratory syndrome, but a small proportion of children develop the systemic Multi Inflammatory Syndrome (MIS-C), characterized by persistent fever and systemic hyperinflammation, with some clinical features resembling Kawasaki Disease (KD).ObjectiveWith this study we aimed to shed new light on the pathogenesis of these two SARS-CoV-2-related clinical manifestations.MethodsWe investigated lymphocyte and dendritic cells subsets, chemokine/cytokine profiles and evaluated the neutrophil activity mediators, myeloperoxidase (MPO), and reactive oxygen species (ROS), in 10 children with COVID-19 and 9 with MIS-C at the time of hospital admission.ResultsPatients with MIS-C showed higher plasma levels of C reactive protein (CRP), MPO, IL-6, and of the pro-inflammatory chemokines CXCL8 and CCL2 than COVID-19 children. In addition, they displayed higher levels of the chemokines CXCL9 and CXCL10, mainly induced by IFN-γ. By contrast, we detected IFN-α in plasma of children with COVID-19, but not in patients with MIS-C. This observation was consistent with the increase of ISG15 and IFIT1 mRNAs in cells of COVID-19 patients, while ISG15 and IFIT1 mRNA were detected in MIS-C at levels comparable to healthy controls. Moreover, quantification of the number of plasmacytoid dendritic cells (pDCs), which constitute the main source of IFN-α, showed profound depletion of this subset in MIS-C, but not in COVID-19.ConclusionsOur results show a pattern of immune response which is suggestive of type I interferon activation in COVID-19 children, probably related to a recent interaction with the virus, while in MIS-C the immune response is characterized by elevation of the inflammatory cytokines/chemokines IL-6, CCL2, and CXCL8 and of the chemokines CXCL9 and CXL10, which are markers of an active Th1 type immune response. We believe that these immunological events, together with neutrophil activation, might be crucial in inducing the multisystem and cardiovascular damage observed in MIS-C.

scholarly journals Free ISG15 as a dimer generates IL-1β-producing CD8α+ dendritic cells at the site of infection

2017 ◽  
Author(s):  
Anna Napolitano ◽  
Annemarthe G. van der Veen ◽  
Monique Bunyan ◽  
Annabel Borg ◽  
Svend Kjaer ◽  
...  
Keyword(s):  
Immune Response ◽  
Dendritic Cells ◽  
Type I ◽  
Type I Ifn ◽  
Independent Manner ◽  
Molecular Determinants ◽  
Live Parasite ◽  
Ifn Γ ◽  
Covalently Linked ◽  
First Time

AbstractISG15 is strongly induced after type I IFN stimulation producing a protein comprised of two ubiquitin-like domains. Intracellularly, ISG15 can be covalently linked and modify the function of target proteins (ISGylation). In addition, free unconjugated ISG15 can be released from cells. We found that ISG15 is released in the serum of Toxoplasma gondii infected mice early after infection in a type-I IFN independent manner. Once in the extracellular space, free ISG15 forms dimers and enhances the release of key cytokines involved in the immune response to the parasite: IL-12, IFN-γ, and IL-1β. Its action is dependent on an actively invading and replicating live parasite. ISG15 induces an increase of IL-1β later during infection by leading to increased IL-1β producing CD8α+ dendritic cells at the site of infection. Here, we define for the first time the molecular determinants of active free ISG15 and link ISG15 to IL-1β production by CD8α+ dendritic cells. Thus we define ISG15 as a novel secreted modulator of the cytokine response during Toxoplasma infection.

scholarly journals Non-Pathogenic Mopeia Virus Induces More Robust Activation of Plasmacytoid Dendritic Cells than Lassa Virus

Viruses ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 287 ◽  
Author(s):  
Justine Schaeffer ◽  
Stéphanie Reynard ◽  
Xavier Carnec ◽  
Natalia Pietrosemoli ◽  
Marie-Agnès Dillies ◽  
...  
Keyword(s):  
Immune Response ◽  
Dendritic Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Plasmacytoid Dendritic Cells ◽  
Health Concern ◽  
Lassa Virus ◽  
Type I ◽  
Viral Haemorrhagic Fever

Lassa virus (LASV) causes a viral haemorrhagic fever in humans and is a major public health concern in West Africa. An efficient immune response to LASV appears to rely on type I interferon (IFN-I) production and T-cell activation. We evaluated the response of plasmacytoid dendritic cells (pDC) to LASV, as they are an important and early source of IFN-I. We compared the response of primary human pDCs to LASV and Mopeia virus (MOPV), which is very closely related to LASV, but non-pathogenic. We showed that pDCs are not productively infected by either MOPV or LASV, but produce IFN-I. However, the activation of pDCs was more robust in response to MOPV than LASV. In vivo, pDC activation may support the control of viral replication through IFN-I production, but also improve the induction of a global immune response. Therefore, pDC activation could play a role in the control of LASV infection.

scholarly journals The Pseudorabies Virus Glycoprotein gE/gI Complex Suppresses Type I Interferon Production by Plasmacytoid Dendritic Cells

2017 ◽  
Vol 91 (7) ◽  
Author(s):  
Jochen A. S. Lamote ◽  
Manon Kestens ◽  
Cliff Van Waesberghe ◽  
Jonas Delva ◽  
Steffi De Pelsmaeker ◽  
...  
Keyword(s):  
Immune Response ◽  
Dendritic Cells ◽  
Vaccine Strain ◽  
Rational Design ◽  
Pseudorabies Virus ◽  
Type I Interferon ◽  
Plasmacytoid Dendritic Cells ◽  
Type I ◽  
Wild Type ◽  
The Impact

ABSTRACT Plasmacytoid dendritic cells (pDC) play a central role in the antiviral immune response, both in the innate response and in shaping the adaptive response, mainly because of their ability to produce massive amounts of type I interferon (TI-IFN). Here, we report that cells infected with the live attenuated Bartha vaccine strain of porcine alphaherpesvirus pseudorabies virus (PRV) trigger a dramatically increased TI-IFN response by porcine primary pDC compared to cells infected with wild-type PRV strains (Becker and Kaplan). Since Bartha is one of the relatively few examples of a highly successful alphaherpesvirus vaccine, identification of factors that may contribute to its efficacy may provide insights for the rational design of other alphaherpesvirus vaccines. The Bartha vaccine genome displays several mutations compared to the genome of wild-type PRV strains, including a large deletion in the unique short (US) region, encompassing the glycoprotein E (gE), gI, US9, and US2 genes. Using recombinant PRV Becker strains harboring the entire Bartha US deletion or single mutations in the four affected US genes, we demonstrate that the absence of the viral gE/gI complex contributes to the observed increased IFN-α response. Furthermore, we show that the absence of gE leads to an enhanced extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation in pDC, which correlates with a higher TI-IFN production by pDC. In conclusion, the PRV Bartha vaccine strain triggers strongly increased TI-IFN production by porcine pDC. Our data further indicate that the gE/gI glycoprotein complex suppresses TI-IFN production by pDC, which represents the first alphaherpesvirus factor that suppresses pDC activity. IMPORTANCE Several alphaherpesviruses, including herpes simpex virus, still lack effective vaccines. However, the highly successful Bartha vaccine has contributed substantially to eradication of the porcine alphaherpesvirus pseudorabies virus (PRV) in several countries. The impact of Bartha on the immune response is still poorly understood. Type I interferon (TI-IFN)-producing plasmacytoid dendritic cells (pDC) may play an important role in vaccine development. Here, we show that Bartha elicits a dramatically increased type I interferon (TI-IFN) response in primary porcine pDC compared to wild-type strains. In addition, we found that the gE/gI complex, which is absent in Bartha, inhibits the pDC TI-IFN response. This is the first description of an immune cell type that is differentially affected by Bartha versus wild-type PRV and is the first report describing an alphaherpesvirus protein that inhibits the TI-IFN response by pDC. These data may therefore contribute to the rational design of other alphaherpesvirus vaccines.

scholarly journals Physiological Role of Plasmacytoid Dendritic Cells and Their Potential Use in Cancer Immunity

2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
Jorge Schettini ◽  
Pinku Mukherjee
Keyword(s):  
Immune Response ◽  
Dendritic Cells ◽  
Tumor Antigens ◽  
Physiological Role ◽  
Plasmacytoid Dendritic Cells ◽  
Type I ◽  
Therapeutic Approaches ◽  
Adaptive Immune ◽  
Type I Ifns

Dendritic cells (DCs) play a pivotal role in the control of innate and adaptive immune responses. They are a heterogeneous cell population, where plasmacytoid dendritic cells (pDCs) are a unique subset capable of secreting high levels of type I IFNs. It has been demonstrated that pDCs can coordinate events during the course of viral infection, atopy, autoimmune diseases, and cancer. Therefore, pDC, as a main source of type I IFN, is an attractive target for therapeutic manipulations of the immune system to elicit a powerful immune response against tumor antigens in combination with other therapies. The therapeutic vaccination with antigen-pulsed DCs has shown a limited efficacy to generate an effective long-lasting immune response against tumor cells. A rational manipulation and design of vaccines which could include DC subsets outside “Langerhans cell paradigm” might allow us to improve the therapeutic approaches for cancer patients.

PLASMACYTOID DENDRITIC CELLS FUNCTION IN HIV INFECTION

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.

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

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.

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

2007 ◽  
Vol 82 (1) ◽  
pp. 196-206 ◽  
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.

scholarly journals STING-Licensed Macrophages Prime Type I IFN Production by Plasmacytoid Dendritic Cells in the Bone Marrow during Severe Plasmodium yoelii Malaria

2016 ◽  
Vol 12 (10) ◽  
pp. e1005975 ◽  
Author(s):  
Emily Spaulding ◽  
David Fooksman ◽  
Jamie M. Moore ◽  
Alex Saidi ◽  
Catherine M. Feintuch ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dendritic Cells ◽  
Plasmodium Yoelii ◽  
Plasmacytoid Dendritic Cells ◽  
Type I ◽  
Type I Ifn ◽  
Prime Type

scholarly journals Type I Interferon Inhibition and Dendritic Cell Activation during Gammaherpesvirus Respiratory Infection

2007 ◽  
Vol 81 (18) ◽  
pp. 9778-9789 ◽  
Author(s):  
Janet L. Weslow-Schmidt ◽  
Nancy A. Jewell ◽  
Sara E. Mertz ◽  
J. Pedro Simas ◽  
Joan E. Durbin ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Dendritic Cell ◽  
Cell Activation ◽  
Type I Interferon ◽  
Plasmacytoid Dendritic Cells ◽  
The Body ◽  
Type I ◽  
Type I Ifn ◽  
Dendritic Cell Activation ◽  
Murine Gammaherpesvirus

ABSTRACT The respiratory tract is a major mucosal site for microorganism entry into the body, and type I interferon (IFN) and dendritic cells constitute a first line of defense against viral infections. We have analyzed the interaction between a model DNA virus, plasmacytoid dendritic cells, and type I IFN during lung infection of mice. Our data show that murine gammaherpesvirus 68 (γHV68) inhibits type I IFN secretion by dendritic cells and that plasmacytoid dendritic cells are necessary for conventional dendritic cell maturation in response to γHV68. Following γHV68 intranasal inoculation, the local and systemic IFN-α/β response is below detectable levels, and plasmacytoid dendritic cells are activated and recruited into the lung with a tissue distribution that differs from that of conventional dendritic cells. Our results suggest that plasmacytoid dendritic cells and type I IFN have important but independent roles during the early response to a respiratory γHV68 infection. γHV68 infection inhibits type I IFN production by dendritic cells and is a poor inducer of IFN-α/β in vivo, which may serve as an immune evasion strategy.

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