Dendritic cell precursor populations of mouse blood: identification of the murine homologues of human blood plasmacytoid pre-DC2 and CD11c+ DC1 precursors

Blood ◽  
2003 ◽  
Vol 101 (4) ◽  
pp. 1453-1459 ◽  
Author(s):  
Meredith O'Keeffe ◽  
Hubertus Hochrein ◽  
David Vremec ◽  
Bernadette Scott ◽  
Paul Hertzog ◽  
...  

Immature and predendritic cells (pre-DCs) of human blood are the most readily accessible human DC sources available for study ex vivo. Murine homologues of human blood DCs have not been described. We report the isolation and characterization of 2 populations of precursor DCs in mouse blood. Mouse blood cells with the surface phenotype CD11cloCD11b−CD45RAhi closely resemble human plasmacytoid cells (or pre-DC2) by morphology and function. On stimulation with oligonucleotides containing CpG motifs (CpG), these cells make large amounts of type 1 interferons and rapidly develop into DCs that bear CD8, though they may be distinct from the CD8+ DCs in the unstimulated mouse. A second population of cells with the surface phenotype CD11c+CD11b+CD45RA− closely resembles the immediate precursors of pre-DC1, rapidly transforming into CD8− DCs after tumor necrosis factor-α (TNF-α) stimulation. These findings indicate the close relationship between human and mouse DCs, provided cells are obtained directly from equivalent source materials.

1997 ◽  
Vol 273 (6) ◽  
pp. R1885-R1890 ◽  
Author(s):  
Tom Van Der Poll ◽  
Stephen F. Lowry

Epinephrine has been found to inhibit the production of the proinflammatory cytokine tumor necrosis factor (TNF)-α and to enhance the production of anti-inflammatory cytokine interleukin (IL)-10. To determine the effect of epinephrine on IL-1β production, the following experiments were performed: 1) blood obtained from subjects at 4–21 h after the start of a continuous infusion of epinephrine (30 ng ⋅ kg−1⋅ min−1) produced less IL-1β after ex vivo stimulation with lipopolysaccharide (LPS), compared with blood drawn from subjects infused with saline; 2) in whole blood in vitro, epinephrine caused a dose-dependent decrease in LPS-induced IL-1β production, which was likely mediated via adrenergic receptors; and 3) inhibition of TNF and enhancement of IL-10 both contributed to epinephrine-induced inhibition of IL-1β production. Epinephrine, either endogenously produced or administered as a component of sepsis treatment, may attenuate excessive activity of proinflammatory cytokines early in the course of systemic infection.


2001 ◽  
Vol 193 (11) ◽  
pp. 1303-1310 ◽  
Author(s):  
Detlef Dieckmann ◽  
Heidi Plottner ◽  
Susanne Berchtold ◽  
Thomas Berger ◽  
Gerold Schuler

It has been known for years that rodents harbor a unique population of CD4+CD25+ “professional” regulatory/suppressor T cells that is crucial for the prevention of spontaneous autoimmune diseases. Here we demonstrate that CD4+CD25+CD45RO+ T cells (mean 6% of CD4+ T cells) are present in the blood of adult healthy volunteers. In contrast to previous reports, these CD4+CD25+ T cells do not constitute conventional memory cells but rather regulatory cells exhibiting properties identical to their rodent counterparts. Cytotoxic T lymphocyte–associated antigen (CTLA)-4 (CD152), for example, which is essential for the in vivo suppressive activity of CD4+CD25+ T cells, was constitutively expressed, and remained strongly upregulated after stimulation. The cells were nonproliferative to stimulation via their T cell receptor for antigen, but the anergic state was partially reversed by interleukin (IL)-2 and IL-15. Upon stimulation with allogeneic (but not syngeneic) mature dendritic cells or platebound anti-CD3 plus anti-CD28 the CD4+CD25+ T cells released IL-10, and in coculture experiments suppressed the activation and proliferation of CD4+ and CD8+ T cells. Suppression proved IL-10 independent, yet contact dependent as in the mouse. The identification of regulatory CD4+CD25+ T cells has important implications for the study of tolerance in man, notably in the context of autoimmunity, transplantation, and cancer.


1996 ◽  
Vol 58 (1-2) ◽  
pp. 15-26 ◽  
Author(s):  
J. Klingensmith ◽  
Y. Yang ◽  
J.D. Axelrod ◽  
D.R. Beier ◽  
N. Perrimon ◽  
...  

2018 ◽  
Vol 315 (5) ◽  
pp. C653-C663 ◽  
Author(s):  
Kasin Yadunandam Anandam ◽  
Omar A. Alwan ◽  
Veedamali S. Subramanian ◽  
Padmanabhan Srinivasan ◽  
Rubina Kapadia ◽  
...  

Riboflavin (RF), is essential for normal cellular metabolism/function. Intestinal RF absorption occurs via a specific carrier-mediated process that involves the apical transporter RFVT-3 ( SLC52A3) and the basolateral RFVT-1 (SLC52A1). Previously, we characterized different cellular/molecular aspects of the intestinal RF uptake process, but nothing is known about the effect of proinflammatory cytokines on the uptake event. We addressed this issue using in vitro, ex vivo, and in vivo models. First, we determined the level of mRNA expression of the human (h)RFVT-3 and hRFVT-1 in intestinal tissue of patients with inflammatory bowel disease (IBD) and observed a markedly lower level compared with controls. In the in vitro model, exposing Caco-2 cells to tumor necrosis factor-α (TNF-α) led to a significant inhibition in RF uptake, an effect that was abrogated upon knocking down TNF receptor 1 (TNFR1). The inhibition in RF uptake was associated with a significant reduction in the expression of hRFVT-3 and -1 protein and mRNA levels, as well as in the activity of the SLC52A3 and SLC52A1 promoters. The latter effects appear to involve Sp1 and NF-κB sites in these promoters. Similarly, exposure of mouse small intestinal enteroids and wild-type mice to TNF-α led to a significant inhibition in physiological and molecular parameters of intestinal RF uptake. Collectively, these findings demonstrate that exposure of intestinal epithelial cells to TNF-α leads to inhibition in RF uptake and that this effect is mediated, at least in part, via transcriptional mechanism(s). These findings may explain the significantly low RF levels observed in patients with IBD.


2006 ◽  
Vol 173 (5) ◽  
pp. 665-671 ◽  
Author(s):  
Yoshitaka Nakamori ◽  
Masahiro Emoto ◽  
Naofumi Fukuda ◽  
Akihiko Taguchi ◽  
Shigeru Okuya ◽  
...  

Tumor necrosis factor-α (TNF-α) signaling through the IκB kinase (IKK) complex attenuates insulin action via the phosphorylation of insulin receptor substrate 1 (IRS-1) at Ser307. However, the precise molecular mechanism by which the IKK complex phosphorylates IRS-1 is unknown. In this study, we report nuclear factor κB essential modulator (NEMO)/IKK-γ subunit accumulation in membrane ruffles followed by an interaction with IRS-1. This intracellular trafficking of NEMO requires insulin, an intact actin cytoskeletal network, and the motor protein Myo1c. Increased Myo1c expression enhanced the NEMO–IRS-1 interaction, which is essential for TNF-α– induced phosphorylation of Ser307–IRS-1. In contrast, dominant inhibitory Myo1c cargo domain expression diminished this interaction and inhibited IRS-1 phosphorylation. NEMO expression also enhanced TNF-α–induced Ser307–IRS-1 phosphorylation and inhibited glucose uptake. In contrast, a deletion mutant of NEMO lacking the IKK-β–binding domain or silencing NEMO blocked the TNF-α signal. Thus, motor protein Myo1c and its receptor protein NEMO act cooperatively to form the IKK–IRS-1 complex and function in TNF-α–induced insulin resistance.


Antibodies ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 50
Author(s):  
Kim Doyon-Laliberté ◽  
Josiane Chagnon-Choquet ◽  
Michelle Byrns ◽  
Matheus Aranguren ◽  
Meriam Memmi ◽  
...  

We have previously characterized a human blood CD19+CD1c+IgM+CD27+CD21loCD10+ innate-like B-cell population, which presents features shared by both transitional immature and marginal zone (MZ) B-cells, named herein “precursor-like” MZ B-cells. B-cells with similar attributes have been associated with regulatory potential (Breg). In order to clarify this issue and better characterize this population, we have proceeded to RNA-Seq transcriptome profiling of mature MZ and precursor-like MZ B-cells taken from the blood of healthy donors. We report that ex vivo mature MZ and precursor-like MZ B-cells express transcripts for the immunoregulatory marker CD83 and nuclear receptors NR4A1, 2, and 3, known to be associated with T-cell regulatory (Treg) maintenance and function. Breg associated markers such as CD39 and CD73 were also expressed by both populations. We also show that human blood and tonsillar precursor-like MZ B-cells were the main B-cell population to express elevated levels of CD83 and NR4A1-3 proteins ex vivo and without stimulation. Sorted tonsillar precursor-like MZ B-cells exerted regulatory activity on autologous activated CD4+ T-cells, and this was affected by a CD83 blocking reagent. We believe these observations shed light on the Breg potential of MZ populations, and identify NR4A1-3 as potential Breg markers, which as for Tregs, may be involved in stabilization of a regulatory status. Since expression and activity of these molecules can be modulated therapeutically, our findings may be useful in strategies aiming at modulation of Breg responses.


2017 ◽  
Vol 43 (6) ◽  
pp. 2170-2184 ◽  
Author(s):  
Jie Ma ◽  
Erich Gulbins ◽  
Michael J. Edwards ◽  
Charles C. Caldwell ◽  
Martin Fraunholz ◽  
...  

Background/Aims: Staphylococcus aureus (S. aureus) infections are a major clinical problem and range from mild skin and soft-tissue infections to severe and even lethal infections such as pneumonia, endocarditis, sepsis, osteomyelitis, and toxic shock syndrome. Toxins that are released from S. aureus mediate many of these effects. Here, we aimed to identify molecular mechanisms how α-toxin, a major S. aureus toxin, induces inflammation. Methods: Macrophages were isolated from the bone marrow of wildtype and acid sphingomyelinase-deficient mice, stimulated with S. aureus α-toxin and activation of the acid sphingomyelinase was quantified. The subcellular formation of ceramides was determined by confocal microscopy. Release of cathepsins from lysosomes, activation of inflammasome proteins and formation of Interleukin-1β (IL-1β) and Tumor Necrosis Factor-α (TNF-α) were analyzed by western blotting, confocal microscopy and ELISA. Results: We demonstrate that S. aureus α-toxin activates the acid sphingomyelinase in ex vivo macrophages and triggers a release of ceramides. Ceramides induced by S. aureus α-toxin localize to lysosomes and mediate a release of cathepsin B and D from lysosomes into the cytoplasm. Cytosolic cathepsin B forms a complex with Nlrc4. Treatment of macrophages with α-toxin induces the formation of IL-1β and TNF-α. These events are reduced or abrogated, respectively, in cells lacking the acid sphingomyelinase and upon treatment of macrophages with amitriptyline, a functional inhibitor of acid sphingomyelinase. Pharmacological inhibition of cathepsin B prevented activation of the inflammasome measured as release of IL-1β, while the formation of TNF-α was independent of cathepsin B. Conclusion: We demonstrate a novel mechanism how bacterial toxins activate the inflammasome and mediate the formation and release of cytokines: S. aureus α-toxin triggers an activation of the acid sphingomyelinase and a release of ceramides resulting in the release of lysosomal cathepsin B and formation of pro-inflammatory cytokines.


Genetics ◽  
1976 ◽  
Vol 82 (2) ◽  
pp. 251-272
Author(s):  
Susan W Liebman ◽  
Fred Sherman ◽  
John W Stewart

ABSTRACT Nonsense suppressors were obtained in a haploid yeast strain containing eight nutritional mutations, that are assumed to be amber or ochre, and the cyc1-179 amber mutation that has a UAG codon corresponding to position 9 in iso-1-cytochrome c. Previous studies established that the biosynthesis and function of iso-1-cytochrome c is compatible with replacements at position 9 of amino acids having widely different structures (Stewart and Sherman 1972). UV-induced revertants, selected on media requiring the reversion of one or two of the amber nutritional markers, were presumed to contain a suppressor if there was the unselected reversion of at least one other marker. The 1088 suppressors that were isolated could be divided into 78 phenotypic classes. Only 43 suppressors of three classes caused the production of more than 50% of the normal amount of iso-1-cytochrome c in the cyc1-179 strain. Genetic analyses indicated that all of these highly efficient amber suppressors are allelic to one or another of the eight suppressors which cause the insertion of tyrosine at ochre (UAA) codons (Gilmore, Stewart and Sherman 1971). Furthermore, only tyrosine has been identified at position 9 in iso-1-cytochrome cin cyc1-179 strains suppressed with these efficient amber suppressors.


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