Group 2 innate lymphoid cells (ILC2s) produce large amounts of IL-5, IL-13, and amphiregulin, which are involved in the development of lung fibrosis. Activation of ILC2s is mediated by phosphorylation of STAT5. Although STAT5 has tyrosine and serine phosphorylation sites, the mechanisms responsible for phosphorylating serine residues and their significance in ILC2s remain unclear.
View Article and Find Full Text PDFHere, we examined the immunomodulating effects of Heyndrickxia coagulans SANK70258 (SANK70258). Mouse splenocytes treated with γ-ray-irradiated SANK70258 produced higher levels of interferon (IFN)-γ than those with 7 types of lactic acid bacteria. IFN-γ was mainly produced by natural killer (NK) cells, involving IL-12/IL-23, dendritic cells (DCs), and NF-κB signaling.
View Article and Find Full Text PDFOur newly developed menthyl esters of valine and isoleucine exhibit anti-inflammatory properties beyond those of the well-known menthol in macrophages stimulated by lipopolysaccharide (LPS) and in a mouse model of colitis induced by sodium dextran sulfate. Unlike menthol, which acts primarily through the cold-sensitive TRPM8 channel, these menthyl esters displayed unique mechanisms that operate independently of this receptor. They readily penetrated target cells and efficiently suppressed LPS-stimulated tumour necrosis factor-alpha (Tnf) expression mediated by liver X receptor (LXR), a key nuclear receptor that regulates intracellular cholesterol and lipid balance.
View Article and Find Full Text PDFShort-chain fatty acids (SCFAs) are produced by the intestinal microbiota during the fermentation of dietary fibers as secondary metabolites. Several recent studies reported that SCFAs modulate the development and function of immune-related cells. However, the molecular mechanisms by which SCFAs regulate mast cells (MCs) remain unclear.
View Article and Find Full Text PDFIn the present study, we evaluated the effects of kaempferol on bone marrow-derived mast cells (BMMCs). Kaempferol treatment significantly and dose-dependently inhibited IgE-induced degranulation, and cytokine production of BMMCs under the condition that cell viability was maintained. Kaempferol downregulated the surface expression levels of FcεRI on BMMCs, but the mRNA levels of FcεRIα, β, and γ-chains were not changed by kaempferol treatment.
View Article and Find Full Text PDFDendritic cells (DCs), which are typical antigen-presenting cells, localize to various sites in the body, particularly the front line of infection as sentinels, and are involved in innate and adaptive immune responses. Although the functions of DCs, such as pathogen-induced cytokine production and antigen-specific T cell activation, are important for host defenses against infection and tumorigenesis, the hyper- and/or extended activation of DCs leads to inflammatory and autoimmune diseases. In the present study, β-damascone, a major ingredient of rose fragrance, was selected from an aroma library as a candidate compound that suppresses antigen-induced immune responses.
View Article and Find Full Text PDFBiotechnol Bioeng
May 2023
Betalains, which consist of the subgroups betaxanthins and betacyanins, are hydrophilic pigments that have classically been used for food colorants. Owing to their strong antioxidant property, their usefulness for application for therapeutic use is also expected. In addition, as betalains are mainly naturally available from plants of the order Caryophyllales, including beet (Beta vulgaris), metabolic engineering for betalain production in crops such as vegetables, fruits and cereals may provide new food resources useful for healthcare.
View Article and Find Full Text PDFGroup 2 innate lymphoid cells (ILC2s) are tissue-resident innate lymphoid cells that express the transcription factor GATA3 as a master regulator, which leads to the production of large amounts of type 2 cytokines, such as IL-5 and IL-13. ILC2s are activated by epithelial cell-derived cytokines, including IL-33 and IL-25, and play a key role in parasite expulsion, allergic responses, tissue repair, and metabolism. In the first five years after the discovery of ILC2s, research mainly focused on their function through cytokine receptors.
View Article and Find Full Text PDFMast cells (MCs) play key roles in IgE-mediated immunoresponses, including in the protection against parasitic infections and the onset and/or symptoms of allergic diseases. IgE-mediated activation induces MCs to release mediators, including histamine and leukotriene, as an early response, and to produce cytokines as a late phase response. Attempts have been made to identify novel antiallergic compounds from natural materials such as Chinese medicines and food ingredients.
View Article and Find Full Text PDFTwo new phenylpropanoids ( and ) and one new isoflavone glycoside (), along with nine known compounds (-), were isolated from the pod of L. Their chemical structures were elucidated based on extensive spectroscopic analyses (1 D and 2 D NMR, UV, IR, and HRESIMS) and compared with the literature data. In addition, all isolated compounds were evaluated for inhibitory activity against acetylcholinesterase (AChE).
View Article and Find Full Text PDFRodent mast cells are classified into two major subsets, mucosal mast cells (MMCs) and connective tissue mast cells. MMCs arise from mast cell progenitors that are mobilized from the bone marrow to mucosal tissues in response to allergic inflammation or helminth infection. TGF-β is known as an inducer of MMC differentiation in mucosal tissues, but we have previously found that Notch receptor-mediated signaling also leads to the differentiation.
View Article and Find Full Text PDFFront Immunol
September 2021
NLRP3 inflammasomes play crucial roles in the initiation of host defense by converting pro-Caspase-1 to mature Caspase-1, which in turn processes immature IL-1β and IL-18 into their biologically active forms. Although NLRP3 expression is restricted to monocytic lineages such as monocytes, macrophages, and dendritic cells, the mechanisms determining the lineage-specific expression of NLRP3 remain largely unknown. In this study, we investigated the transcription factors involved in cell-type-specific transcription of .
View Article and Find Full Text PDFDendritic cells (DCs) and T cells play important roles in immune regulation, and modulating their function is an approach for developing preventive or therapeutic strategies against immune disorders. Herein, the effect of pterostilbene (PSB) (3',5'-dimethoxy-resveratrol)-a resveratrol-related polyphenol found in blueberries-on immune regulation was evaluated. Using an in vitro co-culture system, PSB was found to exert the strongest inhibitory effect among all tested resveratrol derivatives on DC-mediated T cell proliferation; moreover, PSB treatment decreased the Th1 and Th17 populations and increased the regulatory T cell (Treg) population.
View Article and Find Full Text PDFBiochem Biophys Res Commun
September 2020
We evaluated the effect of gut bacterial metabolites of polyunsaturated fatty acids on inflammation and found that 10-oxo-cis-6,trans-11-octadecadienoic acid (γKetoC) strikingly suppressed LPS-induced IL-6 release from bone marrow-derived macrophages (BMMs), which was accompanied by reduced mRNA expression of Il6, TNF, and Il1b. γKetoC decreased the cAMP concentration in BMMs, suggesting that γKetoC stimulated G protein-coupled receptors. A Gq agonist significantly suppressed LPS-induced IL-6 expression in BMMs, whereas a Gi inhibitor partially abrogated γKetoC-mediated IL-6 suppression.
View Article and Find Full Text PDFPD-L2, which has been identified as a PD-1 ligand, is specifically expressed in dendritic cells (DCs) and macrophages. The transcription factors that determine the cell type-specific expression of PD-L2 are largely unknown, although PD-1 and its ligands, which have been shown to play important roles in T cell suppression, have been vigorously analyzed in the field of cancer immunology. To reveal the mechanism by which gene expression is regulated, we focused on DCs, which play key roles in innate and acquired immunity.
View Article and Find Full Text PDFC-C chemokine receptor type 7 (CCR7) is expressed on naïve T cells, B cells, and activated dendritic cells (DCs). We previously demonstrated that the transcription factor PU.1/Spi1 positively regulates the expression of CCR7 in DCs.
View Article and Find Full Text PDFMouse mast cell proteases (mMCP)-1 and -2 are specifically expressed in mucosal mast cells (MCs). However, the transcriptional regulation mechanism of the and genes induced in mucosal MCs is largely unknown. In the current study, we found that TGF-β stimulation drastically induced upregulation of and mRNA in mouse bone marrow-derived MCs (BMMCs).
View Article and Find Full Text PDFMast cells (MCs) play a central role in IgE-dependent immune responses. PPARγ is a nuclear receptor that is essential for adipocyte differentiation and insulin sensitivity. Although PPARγ is expressed in activated MCs, the effect of PPARγ suppression in IgE-mediated activation of MCs is largely unknown.
View Article and Find Full Text PDFC-C chemokine receptor type 7 (CCR7) is essential for migration of dendritic cells (DCs) to draining lymph nodes. PU.1/ is a transcription factor playing a critical role in the gene regulation of DCs.
View Article and Find Full Text PDFThe immunosuppressive activity of myriocin (ISP-1), a lead compound of fingolimod (FTY720), is derived from its 2-amino-1,3-propandiol structure. A non-proteinogenic amino acid, (2S,6R)-diamino-(5R,7)-dihydroxy-heptanoic acid (DADH), that contains this structure, was recently identified as a biosynthetic intermediate of a dipeptide secondary metabolite, vazabitide A, in Streptmyces sp. SANK 60404; however its effect on adaptive immunity has not yet been examined.
View Article and Find Full Text PDFThe chemokine CCL22 is predominantly produced by dendritic cells (DCs) and macrophages. CCL22 acts on CCR4-expressing cells including Th2 and Treg. Although a correlation between the CCL22-CCR4 axis and allergic diseases has been established, the mechanism of monocyte lineage-specific Ccl22 gene expression is largely unknown.
View Article and Find Full Text PDFRALDH2 expressed in dendritic cells (DCs) plays a critical role in the development of regulatory T cells in mesenteric lymph nodes. Despite the importance of RALDH2 in intestinal immunity, little is known about the mechanism of DC-specific expression of RALDH2. In the current study, we focused on the hematopoietic cell-specific transcription factors PU.
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