Project description:IgE-binding monocytes are a rare peripheral immune cell type involved in the allergic response through binding of IgE on their surface. IgE-binding monocytes are present in both healthy and allergic individuals. We performed RNA sequencing to ask how the function of IgE-binding monocytes differs in the context of allergy. Using a large animal model of allergy, equine Culicoides hypersensitivity, we compared the transcriptome of IgE-binding monocytes in allergic and non-allergic horses at two seasonal timepoints: (i) when allergic animals were clinical healthy, in the winter “Remission Phase”, and (ii) during chronic disease, in the summer “Clinical Phase”. Most transcriptional differences between allergic and non-allergic horses occurred only during the “Remission Phase”, suggesting principal differences in monocyte function even in the absence of allergen exposure. F13A1, a subunit of fibrinoligase, was significantly upregulated at both timepoints in allergic horses. This suggested a role for increased fibrin deposition in the coagulation cascade to promote allergic inflammation. IgE-binding monocytes also downregulated CCR10 expression in allergic horses during the “Clinical Phase”, suggesting a defect in maintenance of skin homeostasis, which further promotes allergic inflammation. Together, this transcriptional analysis provides valuable clues into the mechanisms used by IgE-binding monocytes in allergic individuals.
Project description:The lymphocyte stimulation test (LST) helps with the diagnosis of non-IgE-mediated gastrointestinal food allergies. However, The LST requires large volumes of fresh peripheral blood and long culture times.The purpose of this study was to develop a novel LST. we obtained whole blood from patients with non-IgE-GI-FAs to cow’s milk and disease control children. And, we stimulated it with α-casein and Pmix, which is a mixture of four milk protein components (α-casein, κ-casein, α-lactalbumin, or β-lactoglobulin for 24 hours. Then we analyzed genome-wide gene expression using microarray and selected up- or down-regulated genes Nine putative marker genes, including those known to be involved in allergic inflammation, such as IL2RA, CCL17 and CISH were specific to patient group after stimulation with α-casein. On the other hand, 232 marker genes were specific to patient group after stimulation with Pmix.
Project description:The pathological mechanism of the gastrointestinal forms of food allergies is less understood in comparison to other clinical phenotypes, such as asthma, and anaphylaxis, partly due to difficulty in the access to intestinal tissues and because of a highly complex interplay between microbiota and intestinal mucosa. Importantly, a high level of IgE is a poor prognostic factor in gastrointestinal allergies. This study aimed to investigate how IgE influences the development of intestinal inflammation and the metabolome in allergic enteritis (AE), using IgE knock-in (IgEki) mice expressing high levels of IgE. Ovalbumin-sensitized and egg-white diet fed (OVA/EW) BALB/c WT mice developed moderate AE, whereas OVA/EW IgEki mice induced more aggravated intestinal inflammation with enhanced eosinophil accumulation.
Project description:Allergen-specific IgE antibodies mediate allergic pathology in diseases such as allergic rhinitis and food allergy. Memory B cells (MBCs) contribute to circulating IgE by regenerating IgE-producing plasma cells upon allergen encounter. We report a population of type 2 polarized MBCs defined as CD23hi, IL-4Rαhi, CD32low at the transcriptional and surface protein levels.
Project description:Basophils play critical roles in the development of mouse delayed-onset skin allergic inflammation (IgE-CAI model). Importantly, they also contribute to the resolution of allergic inflammation by promoting the generation of pro-resolving macrophages. However, it remains unclear how pro-resolving macrophages suppress excess inflammation. To address this, we conducted single-cell RNA-seq (scRNA-seq) analysis of the IgE-CAI skin lesion at days 3 and 5 post-challenge of allergens. scRNA-seq analysis identified two distinct classical monocyte-derived macrophage (CMDM) populations, namely early and late CMDMs, in IgE-CAI skin lesion. The former population was preferentially observed at the peak of inflammation (day 3), whereas the latter one at the termination phase of inflammation (day 5). Gene ontology analysis revealed that genes associated with phagocytosis were enriched in late CMDMs. In particular, late CMDMs displayed upregulated expression of Gas6 and Mertk, key genes for phagocytic clearance of apoptotic cells. Taken together, scRNA-seq identified CMDMs that display high capacity of dead cell clearance and contribute to the resolution of IgE-CAI.
Project description:Experimental IgE-mediated food allergy depends on intestinal anaphylaxis driven by interleukin (IL)-9. However, the primary cellular source of IL-9 and the mechanisms underlying the susceptibility to food-induced intestinal anaphylaxis remain unclear. Herein, we have reported the identification of multifunctional IL-9-producing mucosal mast cells (MMC9s) that can secrete prodigious amounts of IL-9 and IL-13 in response to IL-33, and mast cell protease-1 (MCPt-1) in response to antigen and IgE complex crosslinking, respectively. Repeated intragastric antigen challenge induced MMC9 development that required T cells, IL-4, and STAT6 transcription factor, but not IL-9 signals. Mice ablated of MMC9 induction failed to develop intestinal mastocytosis, which resulted in decreased food allergy symptoms that could be restored by adoptively transferred MMC9s. Finally, atopic patients that developed food allergy displayed increased intestinal expression of Il9 and MC-specific transcripts. Thus, the induction of MMC9s is a pivotal step to acquire the susceptibility to IgE-mediated food allergy. dUTP mRNA-Seq profiles of indicated hematopoietic cell lineages were generated on Illumina HiSeq2500. Hematopoietic cells were isolated from Balb/C mice that developed food allergy and bone marrow-derived mast cells were generated from naïve Balb/C mice
Project description:Basophils play critical roles in the development of mouse delayed-onset skin allergic inflammation (IgE-CAI model). Importantly, they also contribute to the resolution of allergic inflammation by promoting the generation of pro-resolving macrophages. However, it remains unclear how pro-resolving macrophages suppress excess inflammation. To address this, we conducted single-cell RNA-seq (scRNA-seq) analysis of the IgE-CAI skin lesion at days 3 and 5 post-challenge of allergens. scRNA-seq analysis identified four distinct monocyte-macrophage subpopulations, namely classical monoytes, early CMDMs, late CMDMs and resident-like macrophages. Based on the gene expression profiles, classical monoytes, early CMDMs, late CMDMs and resident-like macrophages corresponded to Ly6ChiPD-L2lo, Ly6ChiPD-L2hi, Ly6CloPD-L2hi, and Ly6CloPD-L2lo, respectively.
Project description:Experimental IgE-mediated food allergy depends on intestinal anaphylaxis driven by interleukin (IL)-9. However, the primary cellular source of IL-9 and the mechanisms underlying the susceptibility to food-induced intestinal anaphylaxis remain unclear. Herein, we have reported the identification of multifunctional IL-9-producing mucosal mast cells (MMC9s) that can secrete prodigious amounts of IL-9 and IL-13 in response to IL-33, and mast cell protease-1 (MCPt-1) in response to antigen and IgE complex crosslinking, respectively. Repeated intragastric antigen challenge induced MMC9 development that required T cells, IL-4, and STAT6 transcription factor, but not IL-9 signals. Mice ablated of MMC9 induction failed to develop intestinal mastocytosis, which resulted in decreased food allergy symptoms that could be restored by adoptively transferred MMC9s. Finally, atopic patients that developed food allergy displayed increased intestinal expression of Il9 and MC-specific transcripts. Thus, the induction of MMC9s is a pivotal step to acquire the susceptibility to IgE-mediated food allergy.
Project description:Purpose: To identify IgE inhibitory bioactive compound from A.Lappa for targeted therapy on peanut specific IgE production and hypersensitivity reactions, and to investigate its underlying mechanisms. The goals of this study were to compare the transcriptome map (RNA-seq) and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) before and after PMBC in patients with food allergy, and to evaluate the most critical genes and signaling pathways which inhibit IgE production by arctigenin.
Project description:Food allergy is caused by allergen-specific IgE but little is known about the B cell memory of persistent responses. Here we describe in pediatric peanut allergy a population of CD23+IgG1 memory B cells that contains peanut-specific clones and generates IgE plasma cells on activation. Through single cell transcriptomics and B cell receptor (BCR) sequencing, we characterized FCER2/CD23+ IgG1 memory B cells co-expressing IL4R, IL13RA1, IGHE and carrying highly mutated BCRs. Further we found that peanut allergen (Ara h 2)-specific B cells were mostly IgG1 memory cells, carried highly mutated BCRs compared to diphtheria toxin-specific B cells, and expressed FCER2 and germlin IGHE. Our findings suggest that CD23+IgG1+ memory B cells transcribing IGHE are a unique memory population containing precursors for pathogenic IgE in food allergy.