scholarly journals Unc93B1 biases Toll-like receptor responses to nucleic acid in dendritic cells toward DNA- but against RNA-sensing

2009 ◽  
Vol 206 (6) ◽  
pp. 1339-1350 ◽  
Author(s):  
Ryutaro Fukui ◽  
Shin-ichiroh Saitoh ◽  
Fumi Matsumoto ◽  
Hiroko Kozuka-Hata ◽  
Masaaki Oyama ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Nucleic Acids ◽  
Toll Like Receptor ◽  
Autoantibody Production ◽  
Adaptive Immune ◽  
Tlr9 Ligand ◽  
Membrane Spanning ◽  
Protein Complementation ◽  
Tlr7 Ligand

Toll-like receptors (TLRs) 3, 7, and 9 recognize microbial nucleic acids in endolysosomes and initiate innate and adaptive immune responses. TLR7/9 in dendritic cells (DCs) also respond to self-derived RNA/DNA, respectively, and drive autoantibody production. Remarkably, TLR7 and 9 appear to have mutually opposing, pathogenic or protective, impacts on lupus nephritis in MRL/lpr mice. Little is known, however, about the contrasting relationship between TLR7 and 9. We show that TLR7 and 9 are inversely linked by Unc93B1, a multiple membrane-spanning endoplasmic reticulum (ER) protein. Complementation cloning with a TLR7-unresponsive but TLR9-responsive cell line revealed that amino acid D34 in Unc93B1 repressed TLR7-mediated responses. D34A mutation rendered Unc93B1-deficient DCs hyperresponsive to TLR7 ligand but hyporesponsive to TLR9 ligand, with TLR3 responses unaltered. Unc93B1 associates with and delivers TLR7/9 from the ER to endolysosomes for ligand recognition. The D34A mutation up-regulates Unc93B1 association with endogenous TLR7 in DCs, whereas Unc93B1 association with TLR9 was down-regulated by the D34A mutation. Consistently, the D34A mutation up-regulated ligand-induced trafficking of TLR7 but down-regulated that of TLR9. Collectively, TLR response to nucleic acids in DCs is biased toward DNA-sensing by Unc93B1.

scholarly journals Eosinophil-derived neurotoxin acts as an alarmin to activate the TLR2–MyD88 signal pathway in dendritic cells and enhances Th2 immune responses

2008 ◽  
Vol 205 (1) ◽  
pp. 79-90 ◽  
Author(s):  
De Yang ◽  
Qian Chen ◽  
Shao Bo Su ◽  
Ping Zhang ◽  
Kahori Kurosaka ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Adaptive Immune System ◽  
Secretory Protein ◽  
Myeloid Differentiation ◽  
Toll Like Receptor ◽  
T Helper ◽  
Adaptive Immune ◽  
Eosinophil Granule ◽  
Myeloid Differentiation Factor

Eosinophil-derived neurotoxin (EDN) is an eosinophil granule–derived secretory protein with ribonuclease and antiviral activity. We have previously shown that EDN can induce the migration and maturation of dendritic cells (DCs). Here, we report that EDN can activate myeloid DCs by triggering the Toll-like receptor (TLR)2–myeloid differentiation factor 88 signaling pathway, thus establishing EDN as an endogenous ligand of TLR2. EDN activates TLR2 independently of TLR1 or TLR6. When mice were immunized with ovalbumin (OVA) together with EDN or with EDN-treated OVA-loaded DCs, EDN enhanced OVA-specific T helper (Th)2-biased immune responses as indicated by predominant production of OVA-specific interleukin (IL)-5, IL-6, IL-10, and IL-13, as well as higher levels of immunoglobulin (Ig)G1 than IgG2a. Based on its ability to serve as a chemoattractant and activator of DCs, as well as the capacity to enhance antigen-specific immune responses, we consider EDN to have the properties of an endogenous alarmin that alerts the adaptive immune system for preferential enhancement of antigen-specific Th2 immune responses.

scholarly journals Rapamycin Alternatively Modifies Mitochondrial Dynamics in Dendritic Cells to Reduce Kidney Ischemic Reperfusion Injury

2021 ◽  
Vol 22 (10) ◽  
pp. 5386
Author(s):  
Maria Namwanje ◽  
Bijay Bisunke ◽  
Thomas V. Rousselle ◽  
Gene G. Lamanilao ◽  
Venkatadri S. Sunder ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Therapeutic Potential ◽  
Ex Vivo ◽  
Mitochondrial Dynamics ◽  
Graft Loss ◽  
Kidney Injury ◽  
Adaptive Immune ◽  
Consumption Rates ◽  
Regulatory Phenotype

Dendritic cells (DCs) are unique immune cells that can link innate and adaptive immune responses and Immunometabolism greatly impacts their phenotype. Rapamycin is a macrolide compound that has immunosuppressant functions and is used to prevent graft loss in kidney transplantation. The current study evaluated the therapeutic potential of ex-vivo rapamycin treated DCs to protect kidneys in a mouse model of acute kidney injury (AKI). For the rapamycin single (S) treatment (Rapa-S-DC), Veh-DCs were treated with rapamycin (10 ng/mL) for 1 h before LPS. In contrast, rapamycin multiple (M) treatment (Rapa-M-DC) were exposed to 3 treatments over 7 days. Only multiple ex-vivo rapamycin treatments of DCs induced a persistent reprogramming of mitochondrial metabolism. These DCs had 18-fold more mitochondria, had almost 4-fold higher oxygen consumption rates, and produced more ATP compared to Veh-DCs (Veh treated control DCs). Pathway analysis showed IL10 signaling as a major contributing pathway to the altered immunophenotype after Rapamycin treatment compared to vehicle with significantly lower cytokines Tnfa, Il1b, and Il6, while regulators of mitochondrial content Pgc1a, Tfam, and Ho1 remained elevated. Critically, adoptive transfer of rapamycin-treated DCs to WT recipients 24 h before bilateral kidney ischemia significantly protected the kidneys from injury with a significant 3-fold improvement in kidney function. Last, the infusion of DCs containing higher mitochondria numbers (treated ex-vivo with healthy isolated mitochondria (10 µg/mL) one day before) also partially protected the kidneys from IRI. These studies demonstrate that pre-emptive infusion of ex-vivo reprogrammed DCs that have higher mitochondria content has therapeutic capacity to induce an anti-inflammatory regulatory phenotype to protect kidneys from injury.

scholarly journals CD8+lineage dendritic cells determine adaptive immune responses to inflammasome activation upon sterile skin injury

2017 ◽  
Vol 27 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Rituparna Chakraborty ◽  
Janin Chandra ◽  
Shuai Cui ◽  
Lynn Tolley ◽  
Matthew A. Cooper ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Inflammasome Activation ◽  
Adaptive Immune Responses ◽  
Skin Injury ◽  
Adaptive Immune

scholarly journals Bisphenol A Does Not Mimic Estrogen in the Promotion of the In Vitro Response of Murine Dendritic Cells to Toll-Like Receptor Ligands

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Marita Chakhtoura ◽  
Uma Sriram ◽  
Michelle Heayn ◽  
Joshua Wonsidler ◽  
Christopher Doyle ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Bisphenol A ◽  
Endocrine Disrupting Chemicals ◽  
Receptor Ligands ◽  
Gm Csf ◽  
Estrogen Receptor Modulators ◽  
Tlr9 Ligand ◽  
In Vitro Response

Sex hormones affect immune responses and might promote autoimmunity. Endocrine disrupting chemicals such as bisphenol A (BPA) may mimic their immune effects. Conventional dendritic cells (cDCs) are pivotal initiators of immune responses upon activation by danger signals coming from pathogens or distressed tissues through triggering of the Toll-like receptors (TLRs). We generated in vitro murine cDCs in the absence of estrogens and measured the effects of exogenously added estrogen or BPA on their differentiation and activation by the TLR ligands LPS and CpG. Estrogen enhanced the differentiation of GM-CSF-dependent cDCs from bone marrow precursors in vitro, and the selective estrogen receptor modulators (SERMs) tamoxifen and fulvestrant blocked these effects. Moreover, estrogen augmented the upregulation of costimulatory molecules and proinflammatory cytokines (IL-12p70 and TNFα) upon stimulation by TLR9 ligand CpG, while the response to LPS was less estrogen-dependent. These effects are partially explained by an estrogen-dependent regulation of TLR9 expression. BPA did not promote cDC differentiation nor activation upon TLR stimulation. Our results suggest that estrogen promotes immune responses by increasing DC activation, with a preferential effect on TLR9 over TLR4 stimulation, and highlight the influence of estrogens in DC cultures, while BPA does not mimic estrogen in the DC functions that we tested.

scholarly journals Dendritic Cells in Innate and Adaptive Immune Responses against Influenza Virus

Viruses ◽  
2009 ◽  
Vol 1 (3) ◽  
pp. 1022-1034 ◽  
Author(s):  
Artur Summerfield ◽  
Kenneth McCullough
Keyword(s):  
Dendritic Cells ◽  
Influenza Virus ◽  
Immune Responses ◽  
Adaptive Immune Responses ◽  
Adaptive Immune

scholarly journals IN LABORATORY GENERATION AND MATURATION OF HUMAN MONOCYTE-DERIVED DENDRITIC CELLS FOR CANCER IMMUNOTHERAPY

2020 ◽  
pp. 46-52
Author(s):  
KANCHAN K. MISHRA ◽  
SUMIT BHARADVA ◽  
MEGHNAD G. JOSHI ◽  
ARVIND GULBAKE
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Gradient Centrifugation ◽  
Critical Role ◽  
Human Monocyte ◽  
Blood Monocytes ◽  
Adaptive Immune ◽  
Immunodeficiency Virus ◽  
Adaptive Immune Systems

Dendritic cells (DCs) play a critical role in the regulation of adaptive immune responses, furthermore they act as a bridge between the innate and the adaptive immune systems they have been ideal candidates for cell-based immunotherapy of cancers and infections in humans. The first reported trial using DCs in 1995, since they have been used in trials all over the world for several of indications, including cancer and human immunodeficiency virus infection. Generally, for in vitro experiments or for DCs vaccination monocyte-derived dendritic cells (moDCs) were generated from purified monocytes that isolated from peripheral blood by density gradient centrifugation. A variety of methods can be used for enrichment of monocytes for generation of clinical-grade DCs. Herein we summarized up to date understanding of systems and inputs used in procedures to differentiate DCs from blood monocytes in vitro.

scholarly journals Dendritic Cells/Macrophages-Targeting Feature of Ebola Glycoprotein and its Potential as Immunological Facilitator for Antiviral Vaccine Approach

2019 ◽  
Vol 7 (10) ◽  
pp. 402
Author(s):  
Titus Abiola Olukitibi ◽  
Zhujun Ao ◽  
Mona Mahmoudi ◽  
Gary A. Kobinger ◽  
Xiaojian Yao
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Ebola Virus ◽  
Vaccine Development ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Immunological Approach ◽  
Vaccine Approach ◽  
Acquired Immune Responses ◽  
Diverse Virus

In the prevention of epidemic and pandemic viral infection, the use of the antiviral vaccine has been the most successful biotechnological and biomedical approach. In recent times, vaccine development studies have focused on recruiting and targeting immunogens to dendritic cells (DCs) and macrophages to induce innate and adaptive immune responses. Interestingly, Ebola virus (EBOV) glycoprotein (GP) has a strong binding affinity with DCs and macrophages. Shreds of evidence have also shown that the interaction between EBOV GP with DCs and macrophages leads to massive recruitment of DCs and macrophages capable of regulating innate and adaptive immune responses. Therefore, studies for the development of vaccine can utilize the affinity between EBOV GP and DCs/macrophages as a novel immunological approach to induce both innate and acquired immune responses. In this review, we will discuss the unique features of EBOV GP to target the DC, and its potential to elicit strong immune responses while targeting DCs/macrophages. This review hopes to suggest and stimulate thoughts of developing a stronger and effective DC-targeting vaccine for diverse virus infection using EBOV GP.

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