Search results for "Toll"
showing 10 items of 324 documents
Anti-inflammatory effects of cinnamon extract and identification of active compounds influencing the TLR2 and TLR4 signaling pathways
2018
Purpose: Inflammatory processes are involved in many diseases. The bark of Cinnamomum verum and its extracts are well known for anti-inflammatory effects, but the underlying active compounds and chemical mechanisms are not yet fully identified. The objective of this study was to elucidate how cinnamon extract, specifically active compounds, and their combinations influence the signaling pathways of inflammation, especially through toll-like receptors TLR2 and TLR4. Methods: Bioassay-guided fractionation was performed for standard ethanolic cinnamon extract using high performance liquid chromatography followed by compound identification in the determined active fractions by high-resolution m…
TLR2, TLR4 and Dectin-1 signalling in hematopoietic stem and progenitor cells determines the antifungal phenotype of the macrophages they produce
2016
TLRs represent an attractive target for the stimulation of myeloid cell production by HSPCs. We have previously demonstrated that HSPCs use TLR2 to sense Candida albicans in vivo and induce the production of macrophages. In this work, we used an in vitro model of HSPCs differentiation to investigate the functional consequences for macrophages of exposure of HSPCs to various PAMPs and C. albicans cells. Mouse HSPCs (Lin(-) cells) were cultured with M-CSF to induce macrophage differentiation, in the presence or absence of the following PRR agonists: Pam3CSK4 (TLR2 ligand), LPS (TLR4 ligand), depleted zymosan (which only activates Dectin-1), or C. albicans yeasts (which activate several PRRs, …
Neuroendocrine Modulation of IL-27 in Macrophages
2017
Abstract Heterodimeric IL-27 (p28/EBV-induced gene 3) is an important member of the IL-6/IL-12 cytokine family. IL-27 is predominantly synthesized by mononuclear phagocytes and exerts immunoregulatory functional activities on lymphocytic and nonlymphocytic cells during infection, autoimmunity or neoplasms. There is a great body of evidence on the bidirectional interplay between the autonomic nervous system and immune responses during inflammatory disorders, but so far IL-27 has not been defined as a part of these multifaceted neuroendocrine networks. In this study, we describe the role of catecholamines (as mediators of the sympathetic nervous system) related to IL-27 production in primary …
Adaptive suppression of the ATF4–CHOP branch of the unfolded protein response by toll-like receptor signalling
2009
The endoplasmic reticulum (ER) unfolded protein response (UPR) restores equilibrium to the ER, but prolonged expression of the UPR effector CHOP (GADD153) is cytotoxic. We found that CHOP expression induced by ER stress was suppressed by prior engagement of toll-like receptor (TLR) 3 or 4 through a TRIF-dependent pathway. TLR engagement did not suppress phosphorylation of PERK or eIF-2alpha, which are upstream of CHOP, but phospho-eIF-2alpha failed to promote translation of the CHOP activator ATF4. In mice subjected to systemic ER stress, pretreatment with low dose lipopolysaccharide (LPS), a TLR4 ligand, suppressed CHOP expression and apoptosis in splenic macrophages, renal tubule cells an…
Reduced expression of TLR4 is associated with the metastatic status of human colorectal cancer.
2007
Signaling mediating colorectal cancer (CRC) progression is incompletely understood. Previously, we identified lipopolysaccharide (LPS), an endotoxin of ubiquitously existing colonic bacteria, as a pivotal stimulus increasing the metastatic potential of human CRC. Since the ubiquitous colonic bacteria release large amounts of LPS this observation could be of enormous relevance for the progression of CRC. In this study we present data contributing to the elucidation of its mode of action. Since both receptors CD14 and TLR4 act as LPS mediators, we determined their expression in various CRC cell lines and in 115 non-metastatic, lymphogenous-metastatic and haematogenous-metastatic CRC specimens…
A member of the Tlr family is involved in dsRNA innate immune response in Paracentrotus lividus sea urchin
2015
Abstract The innate immune response involves proteins such as the membrane receptors of the Toll-like family (TLRs), which trigger different intracellular signalling pathways that are dependent on specific stimulating molecules. In sea urchins, TLR proteins are encoded by members of a large multigenic family composed of 60–250 genes in different species. Here, we report a newly identified mRNA sequence encoding a TLR protein (referred to as Pl-Tlr) isolated from Paracentrotus lividus immune cells. The partial protein sequence contained the conserved Toll/IL-1 receptor (TIR) domain, the transmembrane domain and part of the leucine repeats. Phylogenetic analysis of the Pl-Tlr protein was acco…
Flow cytometric investigation of neutrophil oxidative burst and apoptosis in physiological and pathological situations
2009
Flow cytometric analysis provides a rapid screen for abnormalities of polymorphonuclear neutrophils (PMN) function and reflect their behavior in vivo more accurately. This review summarizes the major fluorescent probes used to study PMN oxidative burst and apoptosis using flow cytometry (FCM). We also provide examples of FCM studies in physiological and pathological situations, illustrating the advantages of FCM for assessment of PMN oxidative burst and PMN apoptosis. These data point to the role of FCM in detecting primary immunodeficiencies such as IRAK4 deficiency and support the use of the assessment of the PMN oxidative burst for routine testing in patients with bacterial infections. W…
Killed Candida albicans yeasts and hyphae inhibit gamma interferon release by murine natural killer cells.
2006
ABSTRACT Killed yeasts and hyphae of Candida albicans inhibit gamma interferon secretion by highly purified murine NK cells in response to the Toll-like receptor ligands lipopolysaccharide and zymosan. This effect, which is also observed in the presence of NK-activating cytokines (interleukin-2 [IL-2], IL-12, and IL-15), may represent a novel mechanism of immune evasion that contributes to the virulence of C. albicans .
Interaction of TLR2 and TLR4 ligands with the N-terminal domain of Gp96 amplifies innate and adaptive immune responses.
2006
Activation of dendritic cells by ligands for Toll-like receptors (TLR) is a crucial event in the initiation of innate and adaptive immune responses. Several classes of TLR ligands have been identified that interact with distinct members of the TLR-family. TLR4 ligands include lipopolysaccharide derived from different Gram-negative bacteria and viral proteins. Recent reports have demonstrated the TLR-mediated activation of dendritic cells by heat shock proteins (HSPs). However, doubts were raised as to what extent this effect was due to lipopolysaccharide contaminations of the HSP preparations. We re-examined this phenomenon using Gp96 or its N-terminal domain, nominally endotoxin-free (0.5 …
Compartmentalized production of CCL17 in vivo: strong inducibility in peripheral dendritic cells contrasts selective absence from the spleen.
2003
Dendritic cells (DCs)(*) fulfill an important regulatory function at the interface of the innate and adaptive immune system. The thymus and activation-regulated chemokine (TARC/CCL17) is produced by DCs and facilitates the attraction of activated T cells. Using a fluorescence-based in vivo reporter system, we show that CCL17 expression in mice is found in activated Langerhans cells and mature DCs located in various lymphoid and nonlymphoid organs, and is up-regulated after stimulation with Toll-like receptor ligands. DCs expressing CCL17 belong to the CD11b(+)CD8(-)Dec205(+) DC subset, including the myeloid-related DCs located in the subepithelial dome of Peyer's patches. CCL17-deficient mi…