scholarly journals Notch–RBP-J signaling controls the homeostasis of CD8− dendritic cells in the spleen

2007 ◽  
Vol 204 (7) ◽  
pp. 1653-1664 ◽  
Author(s):  
Michele L. Caton ◽  
Matthew R. Smith-Raska ◽  
Boris Reizis

Signaling through Notch receptors and their transcriptional effector RBP-J is essential for lymphocyte development and function, whereas its role in other immune cell types is unclear. We tested the function of the canonical Notch–RBP-J pathway in dendritic cell (DC) development and maintenance in vivo. Genetic inactivation of RBP-J in the bone marrow did not preclude DC lineage commitment but caused the reduction of splenic DC fraction. The inactivation of RBP-J in DCs using a novel DC-specific deleter strain caused selective loss of the splenic CD8− DC subset and reduced the frequency of cytokine-secreting CD8− DCs after challenge with Toll-like receptor ligands. In contrast, other splenic DC subsets and DCs in the lymph nodes and tissues were unaffected. The RBP-J–deficient splenic CD8− DCs were depleted at the postprogenitor stage, exhibited increased apoptosis, and lost the expression of the Notch target gene Deltex1. In the spleen, CD8− DCs were found adjacent to cells expressing the Notch ligand Delta-like 1 in the marginal zone (MZ). Thus, canonical Notch–RBP-J signaling controls the maintenance of CD8− DCs in the splenic MZ, revealing an unexpected role of the Notch pathway in the innate immune system.

2013 ◽  
Vol 2013 ◽  
pp. 1-12
Author(s):  
Marisa Vulcano ◽  
María Gabriela Lombardi ◽  
María Elena Sales

Besides being the main neurotransmitter in the parasympathetic nervous system, acetylcholine (ACh) can act as a signaling molecule in nonneuronal tissues. For this reason, ACh and the enzymes that synthesize and degrade it (choline acetyltransferase and acetylcholinesterase) as well as muscarinic (mAChRs) and nicotinic receptors conform the non-neuronal cholinergic system (nNCS). It has been reported that nNCS regulates basal cellular functions including survival, proliferation, adhesion, and migration. Moreover, nNCS is broadly expressed in tumors and in different components of the immune system. In this review, we summarize the role of nNCS in tumors and in different immune cell types focusing on the expression and function of mAChRs in breast tumors and dendritic cells (DCs) and discussing the role of DCs in breast cancer.


2018 ◽  
Vol 115 (20) ◽  
pp. 5253-5258 ◽  
Author(s):  
Hideyuki Yanai ◽  
Shiho Chiba ◽  
Sho Hangai ◽  
Kohei Kometani ◽  
Asuka Inoue ◽  
...  

IFN regulatory factor 3 (IRF3) is a transcription regulator of cellular responses in many cell types that is known to be essential for innate immunity. To confirm IRF3’s broad role in immunity and to more fully discern its role in various cellular subsets, we engineered Irf3-floxed mice to allow for the cell type-specific ablation of Irf3. Analysis of these mice confirmed the general requirement of IRF3 for the evocation of type I IFN responses in vitro and in vivo. Furthermore, immune cell ontogeny and frequencies of immune cell types were unaffected when Irf3 was selectively inactivated in either T cells or B cells in the mice. Interestingly, in a model of lipopolysaccharide-induced septic shock, selective Irf3 deficiency in myeloid cells led to reduced levels of type I IFN in the sera and increased survival of these mice, indicating the myeloid-specific, pathogenic role of the Toll-like receptor 4–IRF3 type I IFN axis in this model of sepsis. Thus, Irf3-floxed mice can serve as useful tool for further exploring the cell type-specific functions of this transcription factor.


2020 ◽  
Vol 21 (13) ◽  
pp. 4768 ◽  
Author(s):  
Susanna R. Var ◽  
Christine A. Byrd-Jacobs

Currently, there is no treatment for recovery of human nerve function after damage to the central nervous system (CNS), and there are limited regenerative capabilities in the peripheral nervous system. Since fish are known for their regenerative abilities, understanding how these species modulate inflammatory processes following injury has potential translational importance for recovery from damage and disease. Many diseases and injuries involve the activation of innate immune cells to clear damaged cells. The resident immune cells of the CNS are microglia, the primary cells that respond to infection and injury, and their peripheral counterparts, macrophages. These cells serve as key modulators of development and plasticity and have been shown to be important in the repair and regeneration of structure and function after injury. Zebrafish are an emerging model for studying macrophages in regeneration after injury and microglia in neurodegenerative disorders such as Parkinson’s disease and Alzheimer’s disease. These fish possess a high degree of neuroanatomical, neurochemical, and emotional/social behavioral resemblance with humans, serving as an ideal simulator for many pathologies. This review explores literature on macrophage and microglial involvement in facilitating regeneration. Understanding innate immune cell behavior following damage may help to develop novel methods for treating toxic and chronic inflammatory processes that are seen in trauma and disease.


Blood ◽  
2010 ◽  
Vol 116 (25) ◽  
pp. 5443-5454 ◽  
Author(s):  
Robin Jeannet ◽  
Jérôme Mastio ◽  
Alejandra Macias-Garcia ◽  
Attila Oravecz ◽  
Todd Ashworth ◽  
...  

Abstract The Notch pathway is frequently activated in T-cell acute lymphoblastic leukemias (T-ALLs). Of the Notch receptors, Notch1 is a recurrent target of gain-of-function mutations and Notch3 is expressed in all T-ALLs, but it is currently unclear how these receptors contribute to T-cell transformation in vivo. We investigated the role of Notch1 and Notch3 in T-ALL progression by a genetic approach, in mice bearing a knockdown mutation in the Ikaros gene that spontaneously develop Notch-dependent T-ALL. While deletion of Notch3 has little effect, T cell–specific deletion of floxed Notch1 promoter/exon 1 sequences significantly accelerates leukemogenesis. Notch1-deleted tumors lack surface Notch1 but express γ-secretase–cleaved intracellular Notch1 proteins. In addition, these tumors accumulate high levels of truncated Notch1 transcripts that are caused by aberrant transcription from cryptic initiation sites in the 3′ part of the gene. Deletion of the floxed sequences directly reprograms the Notch1 locus to begin transcription from these 3′ promoters and is accompanied by an epigenetic reorganization of the Notch1 locus that is consistent with transcriptional activation. Further, spontaneous deletion of 5′ Notch1 sequences occurs in approximately 75% of Ikaros-deficient T-ALLs. These results reveal a novel mechanism for the oncogenic activation of the Notch1 gene after deletion of its main promoter.


2020 ◽  
Author(s):  
Juliet Mwirigi ◽  
Moeno Kume ◽  
Shayne N Hassler ◽  
Ayesha Ahmad ◽  
Pradipta R. Ray ◽  
...  

ABSTRACTThe protease activated receptor (PAR) family is a group of G-protein coupled receptors (GPCRs) activated by proteolytic cleavage of the extracellular domain. PARs are expressed in a variety of cell types with crucial roles in hemostasis, immune responses, inflammation, and pain. PAR3 is the least researched of the four PARs, with little known about its expression and function. We sought to better understand its potential function in the peripheral sensory nervous system. Mouse single-cell RNA sequencing data demonstrates that PAR3 is widely expressed in dorsal root ganglion (DRG) neurons. Co-expression of PAR3 mRNA with other PARs was identified in various DRG neuron subpopulations, consistent with its proposed role as a coreceptor of other PARs. We developed a lipid tethered PAR3 agonist, C660, that selectively activates PAR3 by eliciting a Ca2+ response in DRG and trigeminal (TG) neurons. In vivo, C660 induces mechanical hypersensitivity and facial grimacing in WT but not PAR3-/- mice. We characterized other nociceptive phenotypes in PAR3-/- mice and found a loss of hyperalgesic priming in response to IL-6, carrageenan, and a PAR2 agonist, suggesting that PAR3 contributes to long-lasting nociceptor plasticity in some contexts. To examine a potential role of PAR3 in regulating activity of other PARs in sensory neurons, we administered PAR1, PAR2, and PAR4 agonists and assessed mechanical and affective pain behaviors in WT and PAR3-/- mice. We observed that the nociceptive effects of PAR1 agonists were potentiated in the absence of PAR3. Our findings suggest a complex role of PAR3 in the physiology and plasticity of nociceptors.


2015 ◽  
Vol 112 (30) ◽  
pp. 9394-9399 ◽  
Author(s):  
Chi-Keung Wan ◽  
Allison B. Andraski ◽  
Rosanne Spolski ◽  
Peng Li ◽  
Majid Kazemian ◽  
...  

IL-21 is a type I cytokine essential for immune cell differentiation and function. Although IL-21 can activate several STAT family transcription factors, previous studies focused mainly on the role of STAT3 in IL-21 signaling. Here, we investigated the role of STAT1 and show that STAT1 and STAT3 have at least partially opposing roles in IL-21 signaling in CD4+ T cells. IL-21 induced STAT1 phosphorylation, and this was augmented in Stat3-deficient CD4+ T cells. RNA-Seq analysis of CD4+ T cells from Stat1- and Stat3-deficient mice revealed that both STAT1 and STAT3 are critical for IL-21–mediated gene regulation. Expression of some genes, including Tbx21 and Ifng, was differentially regulated by STAT1 and STAT3. Moreover, opposing actions of STAT1 and STAT3 on IFN-γ expression in CD4+ T cells were demonstrated in vivo during chronic lymphocytic choriomeningitis infection. Finally, IL-21–mediated induction of STAT1 phosphorylation, as well as IFNG and TBX21 expression, were higher in CD4+ T cells from patients with autosomal dominant hyper-IgE syndrome, which is caused by STAT3 deficiency, as well as in cells from STAT1 gain-of-function patients. These data indicate an interplay between STAT1 and STAT3 in fine-tuning IL-21 actions.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Isabelle Lorthois ◽  
Daniel Asselineau ◽  
Nathalie Seyler ◽  
Roxane Pouliot

Psoriasis, a common chronic immune-mediated skin disease, is histologically characterized by a rapid keratinocyte turnover and differentiation defects. Key insights favor the idea that T cells are not the only key actors involved in the inflammatory process. Innate immune cells, more precisely neutrophils and macrophages, provide specific signals involved in the initiation and the maintenance of the pathogenesis. Current data from animal models and, to a lesser extent, three-dimensionalin vitromodels have confirmed the interest in leaning towards other immune cell types as a potential new cellular target for the treatment of the disease. Although these models do not mimic the complex phenotype nor all human features of psoriasis, their development is necessary and essential to better understand reciprocal interactions between skin cells and innate immune cells and to emphasize the crucial importance of the local lesional microenvironment. In this review, through the use ofin vivoand 3D organotypic models, we aim to shed light on the crosstalk between epithelial and immune components and to discuss the role of secreted inflammatory molecules in the development of this chronic skin disease.


2019 ◽  
Vol 2019 ◽  
pp. 1-30 ◽  
Author(s):  
Giorgio Aquila ◽  
Luisa Marracino ◽  
Valeria Martino ◽  
Donato Calabria ◽  
Gianluca Campo ◽  
...  

Despite the currently available pharmacotherapies, today, thirty percent of worldwide deaths are due to cardiovascular diseases (CVDs), whose primary cause is atherosclerosis, an inflammatory disorder characterized by the buildup of lipid deposits on the inside of arteries. Multiple cellular signaling pathways have been shown to be involved in the processes underlying atherosclerosis, and evidence has been accumulating for the crucial role of Notch receptors in regulating the functions of the diverse cell types involved in atherosclerosis onset and progression. Several classes of nutraceuticals have potential benefits for the prevention and treatment of atherosclerosis and CVDs, some of which could in part be due to their ability to modulate the Notch pathway. In this review, we summarize the current state of knowledge on the role of Notch in vascular health and its modulation by nutraceuticals for the prevention of atherosclerosis and/or treatment of related CVDs.


2021 ◽  
Vol 12 ◽  
Author(s):  
Heather L. Caslin ◽  
Daniel Abebayehu ◽  
Julia A. Pinette ◽  
John J. Ryan

Lactate and the associated H+ ions are still introduced in many biochemistry and general biology textbooks and courses as a metabolic by-product within fast or oxygen-independent glycolysis. However, the role of lactate as a fuel source has been well-appreciated in the field of physiology, and the role of lactate as a metabolic feedback regulator and distinct signaling molecule is beginning to gain traction in the field of immunology. We now know that while lactate and the associated H+ ions are generally immunosuppressive negative regulators, there are cell, receptor, mediator, and microenvironment-specific effects that augment T helper (Th)17, macrophage (M)2, tumor-associated macrophage, and neutrophil functions. Moreover, we are beginning to uncover how lactate and H+ utilize different transporters and signaling cascades in various immune cell types. These immunomodulatory effects may have a substantial impact in cancer, sepsis, autoimmunity, wound healing, and other immunomodulatory conditions with elevated lactate levels. In this article, we summarize the known effects of lactate and H+ on immune cells to hypothesize potential explanations for the divergent inflammatory vs. anti-inflammatory effects.


1999 ◽  
Vol 81 (06) ◽  
pp. 951-956 ◽  
Author(s):  
J. Corral ◽  
R. González-Conejero ◽  
J. Rivera ◽  
F. Ortuño ◽  
P. Aparicio ◽  
...  

SummaryThe variability of the platelet GP Ia/IIa density has been associated with the 807 C/T polymorphism (Phe 224) of the GP Ia gene in American Caucasian population. We have investigated the genotype and allelic frequencies of this polymorphism in Spanish Caucasians. The T allele was found in 35% of the 284 blood donors analyzed. We confirmed in 159 healthy subjects a significant association between the 807 C/T polymorphism and the platelet GP Ia density. The T allele correlated with high number of GP Ia molecules on platelet surface. In addition, we observed a similar association of this polymorphism with the expression of this protein in other blood cell types. The platelet responsiveness to collagen was determined by “in vitro” analysis of the platelet activation and aggregation response. We found no significant differences in these functional platelet parameters according to the 807 C/T genotype. Finally, results from 3 case/control studies involving 302 consecutive patients (101 with coronary heart disease, 104 with cerebrovascular disease and 97 with deep venous thrombosis) determined that the 807 C/T polymorphism of the GP Ia gene does not represent a risk factor for arterial or venous thrombosis.


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