Project description:Severe infection commonly results in T cell aging, which leads to impaired pathogen clearance or increased secondary infection in both humans and animals. However, the exact mechanisms remain poorly understood. Here, we demonstrated that severe infection-induced IL-33 production resulted in acute thymic involution-mediated naive T cell aging and impaired host control of infection in mouse disease models of schistosomiasis or sepsis. Furthermore, we illustrated that IL-33 triggered excessive generation of medullary thymic epithelial cell (mTEC) IV (thymic tuft cells) in a Pou2f3-dependent manner, as a consequence, disturbed mTEC/cortical TEC (cTEC) compartment and caused acute thymic involution during severe infection. More importantly, IL-33 deficiency or IL-33 receptor ST2 deficient thymus transplantation rescued T-cell immunity to better control infection in mice. Our findings not only uncover a novel link between severe infection-induced IL-33 and thymic involution-mediated naive T cell aging, but also suggest that targeting IL-33 or ST2 is a promising strategy to rejuvenate T cell immunity to better control severe infection.
Project description:Mast cells are tissue resident granulocytes which are most abundant at the interface between tissues and the external environment, such as around blood vessels, in the skin or mucosal surfaces in the lungs and gut. Pathologically they are involved in allergic reactions and anaphylaxis, however they may also play protective roles in responses to some infections, particularly to pathogenic helminths. Mast cells also express high levels of the IL-33 receptor, which like TLRs, activates Myd88 dependent signalling pathways to drive de novo cytokine production in mast cells.IL-33 is a member of the IL-1 family known to stimulate a number of immune cell types including mast cells. IL-33 is a strong activator of de novo cytokine production in mast cells without inducing degranulation, although it has also been shown to synergise with other signals to promote degranulation. Bone Marrow-Derived Mast cells (BMMCs) were cultured as described previously [27]. Briefly, bone marrow was flushed in PBS and the cells pelleted by centrifugation. Cells were cultured at 1 million cells per ml in RPMI 1640 supplemented with 10% FBS (Biosera/Labtech), 5 mM l‐Glutamine (GIBCO Life Technologies), 100 U/ml Penicillin (GIBCO Life Technologies), 100 μg/ml Streptomycin (GIBCO Life Technologies), 25 mM HEPES (Lonza), 1 mM sodium pyruvate (Lonza), 1X nonessential amino acids (Lonza), 50 μM 2‐mercaptoethanol and 30 ng/ml IL‐3 (PeproTech). Cells were passaged twice per week and used between passage 12 and 16. 4 independent BMMC cultures were either stimulated with 10 ng/ml IL-33 for 48 hours or left unstimulated, followed by single shot LC-MS analysis.
Project description:We report gene expression of Treg cells isolated from injured muscle in IL-33 vs PBS treated mice. Male Foxp3-GFP C57BL/6 reporter (2 months old) mice were injured intramuscularly with cardiotoxin/rIL-33 (0.3 ug/muscle). Tregs were sorted directly into Trizol from injured muscle 4 days post-injury. Gene expression profiling of muscle Tregs from IL-33 vs PBS injured mice.
Project description:Interleukin-33 (IL-33) is a novel member of the IL-1 family of cytokines that plays diverse roles in the regulation of immune responses. IL-33 exerts its effects by binding to a heterodimeric receptor complex consisting of interleukin-1 receptor like 1 (IL1RL1) and an accessory receptor protein IL-1RAcP resulting in the production and release of proinflammatory cytokines. A detailed understanding of the signaling pathways activated by IL-33 remains elusive. To elucidate IL-33 mediated signaling, we performed a global quantitative phosphoproteomic analysis using stable isotope labeling by amino acids in cell culture. Employing anti-phosphotyrosine antibodies and titanium dioxide-based enrichment strategies, we identified 6,207 phosphorylation sites mapping to 2,013 phosphoproteins of which more than 185 phosphosites are regulated by IL-33 stimulation. Our findings will greatly expand the understanding of IL-33 signaling and provide novel therapeutic targets for IL-33/IL-33R-associated diseases in humans.
Project description:The thymus is one of the most affected organs during malnutrition, exhibiting atrophy and thymocyte depletion, characteristics that are also observed in several infectious diseases. The detrimental effects of malnutrition on immune responses to pathogens have long been recognized and it is considered a main risk factor for various infectious diseases, including visceral leishmaniasis (VL). However, the thymus has been barely studied during malnutrition and Leishmania infantum infection association. Protein malnutrition modifies intrathymic communication in L. infantum infected BALB/c mice by altering the abundance of proteins secreted to the thymic interstitial fluid (IF). We identified and compared protein abundance in the thymic IF samples from BALB/c mice that were fed with control protein (14%, CP) or low protein (4%, LP) isocaloric diets, followed by infection with L. infantum. By means of a quantitative proteomics approach using iTRAQ we identified 280 proteins of which 81% were reported as secreted by exosomes and 42% were previously described as secreted by thymic epithelial cells. LP-infected (LPi) animals showed a significant decrease in exosomal proteins, suggesting that exosomal carrier system is dysregulated in malnourished animals. LPi mice also exhibited an increase in the relative abundance of proteins involved in lipid metabolism and tricarboxylic acid cycle, suggestive of a non-proliferative microenvironment. Accordingly, flow cytometry analysis revealed that protein malnutrition decreases the proliferation of single positive and double positive T cells. Proteins engaged in glycolysis, protein ubiquitination and mRNA processing were significantly decreased. In addition, a significant decrease in the abundance of galectin-1 and increase of plasminogen were observed in malnourished animals. Together, the reduced cortical area, decreased proliferation, increased abundance of lipid- and tricarboxylic acid cycle-related proteins, and altered abundance of galectin-1 and plasminogen indicate a dysfunctional thymic microenvironment, where T cell migration, proliferation and maturation are compromised, contributing for the thymic atrophy observed in malnourished animals. All these alterations affect the control of the local and systemic infection, resulting in an impaired response to L. infantum infection.
Project description:IL-33 is a nuclear cytokine from the IL-1 family that plays important roles in health and disease. Under healthy conditions, IL-33 is constitutively expressed to high levels in the nucleus of producing cells in various human and mouse tissues. The extracellular function of IL-33 cytokine has been well documented, but it remains unclear whether intracellular nuclear IL-33 has additional functions in the nucleus. Here, we used a global proteomic approach based on quantification of 5000 individual proteins by high-resolution mass spectrometry to compare the extracellular and intracellular roles of IL-33 in primary human endothelial cells, a major source of IL-33 protein in human tissues. Large-scale analysis of protein expression was performed either after stimulation of the cells with the IL-33 mature form IL-3395-270 (during 6h or 24h) or after siRNA knockdown of intracellular IL-33 (two experiments, each with a different pool of distinct siRNAs, noted siRNA1 and siRNA2). In each case, proteins were fractionated by 1D SDS-PAGE in 12 gel bands, and label-free quantitative analysis was performed. The present dataset contains the files for the two experiments of knockdown of endogenous nuclear IL-33 expression: - RNA silencing strategy 1. Knockdown of endogenous nuclear IL-33 expression was performed with a pool of four distinct siRNAs (Dharmacon ON-TARGETplus SMARTpool IL-33 siRNAs) that have been specifically modified for efficient silencing of the target gene with reduced off-target effects. Cells transfected with these siRNA duplexes (si1) were compared with those transfected with the provided controls (CTsi1). Three independent biological replicates (noted _A, _B, _C) were prepared and analyzed for each condition, leading to 6 different samples. Each of them was fractionated into 12 gel bands analyzed by nanoLC-MS/MS, leading to 72 raw files. - RNA silencing strategy 2. The second knockdown strategy was based on the use of an independent pool of three siRNAs targeting IL-33, predesigned by another provider using new and critical siRNA design rules (Sigma MISSION Predesigned Il-33 siRNAs based on Rosetta siRNA design algorithm). Cells transfected with these siRNA duplexes (si2) were compared with those transfected with the provided controls (CTsi2). Three independent biological replicates (noted _A, _B, _C) were prepared and analyzed for each condition, leading to 6 different samples. Each of them was fractionated into 12 gel bands analyzed by nanoLC-MS/MS, leading to 72 raw files.
Project description:The current model of hematopoiesis only resolves the thymus around the production and establishment of the peripheral T cell pool. However, the role and in situ development of other immune subsets has been overlooked. We aim to demonstrate that during TL1A and IL-18 induced inflammation, the thymus is capable of producing other cell types such as neutrophils, monocytes, and macrophages and that these potentially have other functions aside from supporting T cell development as scavengers. Here we have proven that ex vivo and in vivo treatment with TL1A and IL-18 results in acute thymic atrophy by a massive loss of DP T cells and shrinking of the thymic lobe. By electron microscopy, flow cytometry and single cell we demonstrate that neutrophils are able to maturate inside the thymus lobe in a NOTCH-independent manner. We used fate-mapping tools to elucidate the origin of thymic neutrophils since we observed a great expansion in our culture that is isolated from the influx of BM progenitors. The Rag1-Cre Rosa26-YFP fate mapping model revealed that neutrophils share a common progenitor with T cells, while monocytes/macrophages do not. Furthermore, we found that most of the thymic GMPs (defined as Lin-Sca-1-c-Kit+CD16/32+CD34+) show history of Rag1 expression in comparison with bone marrow GMPs. Additionally, by using Ms4a3-Cre Rosa26Tdtomato fate mapping model we observed that there was not difference in Tdt labeling between the thymus and bone marrow, suggesting that thymic neutrophils still undergo conventional neutrophils pathway arising from GMPs. Moreover, we show that thymic-derived neutrophils are functional and are capable of forming extracellular neutrophils traps (NETs) similarly to benchmark peritoneal neutrophils. We found that the expansion of thymic neutrophils is GM-CSF dependent by using Csf2rb KO mice. Additionally, we identified DR3+ and IL-18Rα+ expressing subsets of ILCs and gdT cells as the cellular source GM-CSF. Lastly, in vivo treatment with TL1A+IL-18 lead to emergency granulopoiesis and an increase of neutrophils in all the organs investigated, including the thymus.
Project description:Determination of the molecular mechanism of IL33 on glioma cells Since IL-33 is known to associate with chromatin and regulate transcriptional activity and that nuclear expression of IL-33 increases glioma progression, we determined Nuclear IL-33 regulates the expression and secretion of inflammatory cytokines in glioma cells. Using these parameters 340 genes were induced by the ectopic expression of IL-33 and an additional 377 genes were downregulated. Gene ontology terms over-represented in the genes induced by IL-33 include three major clusters that associate with cytokine activity and inflammation
Project description:Interleukin-33 (IL-33), a member of the IL-1 superfamily cytokines, is an endogenous danger signal and a nuclear-associated cytokine. It is one of the essential mediators of both innate and adaptive immune responses. Aberrant IL-33 signaling has been demonstrated to play a defensive role against various infectious and inflammatory diseases. Although the signaling responses mediated by IL-33 have been previously reported, the temporal signalingdynamicsare yet to be explored. Towards this end,we applied quantitative temporal phosphoproteomics analysis to elucidate pathways and proteins induced by IL-33 in THP1 monocytes. Employing TMT labeling-based quantitation and titanium dioxide (TiO2)-based phosphopeptide enrichment strategy followed by mass spectrometry analysis, we identified 14,515 phosphorylation sites mapping to 4,174 proteins across (0 min to 240 mins)time points.
Project description:We report gene expression of Treg cells isolated from injured muscle in IL-33 vs PBS treated mice. Male Foxp3-GFP C57BL/6 reporter (2 months old) mice were injured intramuscularly with cardiotoxin/rIL-33 (0.3 ug/muscle). Tregs were sorted directly into Trizol from injured muscle 4 days post-injury.