TLR3 overexpression induces invasion of prostate cancer cells, whereas its activation triggers apoptosis
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE185953 | GEO | 2022/05/19
REPOSITORIES: GEO
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Project description:TLR3 overexpression induces invasion of prostate cancer cells, whereas its activation triggers apoptosis
| PRJNA771529 | ENA
Project description:The Drosophila Taiman (Tai) protein is homologous to the human steroid-receptor coactivators SRC1-3 and activates transcription in complex with the 20-hydroxyecdysone (20E) receptor (EcR). Tai has roles in intestinal homeostasis, germline maintenance, cell motility and proliferation through interactions with EcR and the coactivator Yorkie (Yki). Tai also promotes invasion of tumor cells in adjacent organs, but this pro-invasive mechanism is undefined. Here we show that Tai expression transforms sessile pupal wing cells into an invasive mass that penetrates the adjacent thorax during a period of high 20E. Candidate analysis confirms a reliance on elements of the 20E and Hippo pathways, such as Yki and the Yki-Tai target dilp8. Screening the Tai-induced wing transcriptome detects enrichment for innate immune factors, including the Spätzle (Spz) family of secreted Toll ligands that induce apoptosis during cell competition. Tai-expressing wing cells induce immune signaling and apoptosis among adjacent thoracic cells, and genetic reduction of spz, Toll or the rpr/hid/grim pro-apoptotic factors each suppresses invasion, suggesting an intercellular Spz-Toll circuit supports killing-mediated invasion. Modeling these interactions in larval epithelia confirms that Tai kills neighboring cells via a mechanism involving Toll, Spz factors, and the Spz-inhibitor Necrotic. Tai-expressing cells evade death signals by repressing the immune deficiency (IMD) pathway, which operates in parallel to Toll to control NFkB activity, and independently regulates JNK activity. In sum, these findings suggest that Tai promotes competitive cell killing via Spz-Toll, and that this killing mechanism supports pathologic intertissue invasion in Drosophila.
2020-06-15 | GSE133307 | GEO
Project description:The objective of this study is to study the Toll-like receptor 3 (TLR3)-dependent gene expression in human fibroblast cells and peripheral blood mononuclear cells (PBMCs)
2011-11-02 | GSE30951 | GEO
Project description:Toll-like receptor (TLR) agonists have received considerable attention as therapeutic targets for cancer immunotherapy owing to their ability to convert immunosuppressive tumor microenvironments towards a more T-cell inflamed phenotype. However, TLRs differ in their cell expression profiles and intracellular signaling pathways, raising the possibility that distinct TLRs differentially influence the tumor immune microenvironment.
2021-07-16 | GSE179449 | GEO
Project description:The objective of this study is to study the Toll-like receptor 3 (TLR3)-dependent gene expression in human fibroblast cells and peripheral blood mononuclear cells (PBMCs) Fibroblast cells and PBMCs from donors with autosomal recessive (AR) complete TLR3 deficiency and autosomal dominant (AD) partial TLR3 deficiency were collected for microarray analysis to measure the transcriptional responsiveness of TLR3 in fibroblast and PBMCs. A total of 3 healthy controls, 1 AD TLR3-deficient patient, 1 AR TLR3-deficient patient, 1 AR UNC-93B-deficient patient, 1 MyD88 deficient patien were used in this study. The fibroblast cells were cultured in DMEM medium supplemented with 10% fetal calf serum (FCS). The PBMCs were cultured in RPMI medium complemented with 10% FCS. Different kinetics (2 hours and 8 hours) of poly(I:C) (25ug/ml, purchased from Amersham) stimulations were performed, aiming to define TLR3-inducible genes in these human cells. A stimulation of IL-1β (20ng/ml, purchased from R&D system Inc.) was used as a positive activation control with same kinetics of stimulations. A total of one million cells per stimulation were used for fibroblasts, and around 1.5 million cells per stimulation for PBMCs.
2011-11-02 | E-GEOD-30951 | biostudies-arrayexpress
Project description:Interleukin-24 (IL-24), a member of the IL-10 cytokine family whose physiological function remains largely unknown, has been shown to induce apoptosis when expressed in an adenoviral background. It is yet little understood, why IL-24 alone induced apoptosis only in a limited number of tumor cell lines. Analyzing an influenza A virus vector expressing IL-24 for its oncolytic potential revealed enhanced pro-apoptotic activity of the chimeric virus compared with virus or IL-24 alone. Interestingly, IL-24-mediated enhancement of influenza-A-induced apoptosis did not require viral replication but critically depended on toll-like receptor 3 (TLR3) and caspase-8. Immunoprecipitation of TLR3 showed that infection by influenza A virus induced formation of a TLR3-associated signaling complex containing TRIF, RIP1, FADD, cFLIP and pro-caspase-8. Co-administration of IL-24 decreased the presence of cFLIP in the TLR3-associated complex, converting it into an atypical, TLR3-associated death-inducing signaling complex (TLR3 DISC) that induced apoptosis by enabling caspase-8 activation at this complex. The sensitizing effect of IL-24 on TLR3-induced apoptosis, mediated by influenza A virus or the TLR3-specific agonist poly(I:C), was also evident on tumor spheroids. In conclusion, rather than acting as an apoptosis inducer itself, IL-24 sensitizes cancer cells to TLR-mediated apoptosis by enabling the formation of an atypical DISC which, in the case of influenza A virus or poly(I:C), is associated with TLR3.
| S-EPMC3647237 | biostudies-literature
Project description:Outcome and resolution of an udder inflammation (mastitis) depends on the type of the invading pathogen. Gram-negative pathogens, such as Escherichia coli mostly trigger strong inflammation and full local activation of the immune defense eventually resulting in pathogen elimination. Staphylococcus aureus and other Gram-positive pathogens elicit only weak immune reactions possibly allowing for pathogen persistence. Little is known about the very early molecular determinants of this pathogen-species specific immune response of the udder. We therefore infected healthy mid-lactating heifers with a high dose of defined E. coli1303 or S. aureus1027 pathogens, sampled udder tissues at 1, 2, and 3 h post infection and globally profiled the transcriptome of samples from the gland cistern. We expectedly found that the E. coli infection elicited a fast and strong immune response. Bioinformatics analyses suggested that pathogen recognizing receptors triggered the activation of the IkB/NF-kB signaling cascade inducing the expression of a wealth of inflammation related genes, but also many immune dampeners. S. aureus infection failed to elicit inflammation and activate IkB/NF-kB signaling. Instead, it triggered immune suppressive mechanisms which were, however not outweighed by strong induction of inflammatory genes. Moreover, it activated the wnt/b-catenin signaling cascade resulting in active suppression of NF-kB signaling and rearrangement of the actin-cytoskeleton through modulating expression of the Rho GTPases. These alterations facilitate invasion of pathogens into host cells. We validated experimentally that pathogenic S. aureus, but not E. coli may invade mammary epithelial cells (MEC). Microscopy revealed an altered structure of the actin-cytoskeleton of primary MEC having internalized live GFP-tagged S. aureus pathogens. Our study reveals for the first time the earliest host responses in the udder differentiating E. coli from S. aureus mastitis. The latter is characterized by eliciting immune suppression rather than inflammation and invasion of S. aureus into the epithelial cells of the host.
2017-08-30 | GSE94056 | GEO
Project description:Glycosphingolipids are important structural constituents of cellular membranes. They are involved in the formation of nanodomains ("lipid rafts"), which serve as important signaling platforms. Invasive bacterial pathogens exploit these signaling domains to trigger actin polymerization for the bending of the plasma membrane and the engulfment of the bacterium--a key process in bacterial uptake. However, it is unknown whether glycosphingolipids directly take part in the membrane invagination process. Here, we demonstrate that a "lipid zipper," which is formed by the interaction between the bacterial surface lectin LecA and its cellular receptor, the glycosphingolipid Gb3, triggers plasma membrane bending during host cell invasion of the bacterium Pseudomonas aeruginosa. In vitro experiments with Gb3-containing giant unilamellar vesicles revealed that LecA/Gb3-mediated lipid zippering was sufficient to achieve complete membrane engulfment of the bacterium. In addition, theoretical modeling elucidated that the adhesion energy of the LecA-Gb3 interaction is adequate to drive the engulfment process. In cellulo experiments demonstrated that inhibition of the LecA/Gb3 lipid zipper by either lecA knockout, Gb3 depletion, or application of soluble sugars that interfere with LecA binding to Gb3 significantly lowered P. aeruginosa uptake by host cells. Of note, membrane engulfment of P. aeruginosa occurred independently of actin polymerization, thus corroborating that lipid zippering alone is sufficient for this crucial first step of bacterial host-cell entry. Our study sheds new light on the impact of glycosphingolipids in the cellular invasion of bacterial pathogens and provides a mechanistic explication of the initial uptake processes.
| S-EPMC4156737 | biostudies-literature
Project description:Hepatitis C virus (HCV) is the most common chronic blood-borne infection in the United States with the majority of patients becoming chronically infected and a subset (20%) progressing to cirrhosis and hepatocellular carcinoma. Individual variations in immune responses may help define successful resistance to infection with HCV. We have examined the immune response in primary macrophages from patients who have spontaneously cleared HCV (viral load negative, VL-, n = 37) compared to HCV genotype 1 chronically infected (VL+) subjects (n=32) and found that macrophages from VL- subjects have an elevated baseline expression of Toll-like receptor 3 (TLR3). Macrophages from HCV patients were stimulated ex vivo through the TLR3 pathway and assessed using gene expression arrays and pathway analysis. We found elevated TLR3 response genes and pathway activity from VL- subjects. Furthermore, macrophages from VL- subjects showed higher production of IFN-b and related IFN response genes by Q-PCR, and increased phosphorylation of STAT-1 by immunoblot. Analysis of polymorphisms in TLR3 revealed a significant association of intronic TLR3 polymorphism (rs13126816) with the clearance of HCV and the expression of TLR3. Of note, PBMCs from the same donors showed opposite changes in gene expression, suggesting ongoing inflammatory responses in PBMCs from VL+ HCV patients. Our results suggest that an elevated innate immune response enhances HCV clearance mechanisms and may offer a potential therapeutic approach to increase viral clearance. Differential gene expression by primary human macrophages and PBMCs from patients with spontaneous clearance of HCV (VL-) and patients with chronic HCV infection (VL+) were generated by microarray.
2013-03-05 | E-GEOD-40812 | biostudies-arrayexpress
Project description:Mammalian cells were observed to die under conditions in which nutrients were depleted and, simultaneously, macroautophagy was inhibited either genetically (by a small interfering RNA targeting Atg5, Atg6/Beclin 1-1, Atg10, or Atg12) or pharmacologically (by 3-methyladenine, hydroxychloroquine, bafilomycin A1, or monensin). Cell death occurred through apoptosis (type 1 cell death), since it was reduced by stabilization of mitochondrial membranes (with Bcl-2 or vMIA, a cytomegalovirus-derived gene) or by caspase inhibition. Under conditions in which the fusion between lysosomes and autophagosomes was inhibited, the formation of autophagic vacuoles was enhanced at a preapoptotic stage, as indicated by accumulation of LC3-II protein, ultrastructural studies, and an increase in the acidic vacuolar compartment. Cells exhibiting a morphology reminiscent of (autophagic) type 2 cell death, however, recovered, and only cells with a disrupted mitochondrial transmembrane potential were beyond the point of no return and inexorably died even under optimal culture conditions. All together, these data indicate that autophagy may be cytoprotective, at least under conditions of nutrient depletion, and point to an important cross talk between type 1 and type 2 cell death pathways.
| S-EPMC543994 | biostudies-literature