Project description:IgE-producing memory cells are hard to detect in the periphery. Here, we sorted IgE+ memory B cells from allergic patients who had received allergen-immunotherapy for grass pollen. Cells were FACS-sorted and subseuqenlty sequenced by single cell RNAseq to determine isotype and phenotype. Two out of 90 cells were determiend to be true IgE producing memory B cells.
Project description:Background: Multiple regulatory mechanisms have been identified employing conventional hypothesis-driven approaches as contributing to allergen-specific immunotherapy outcomes, but understanding of how these integrate to maintain immunological homeostasis is incomplete. Objective: To explore the potential for unbiased systems-level gene co-expression network analysis to advance understanding of immunotherapy mechanisms. Methods: We profiled genome-wide allergen-induced Th-cell responses prospectively during 24 months subcutaneous immunotherapy (SCIT) in 25 rhinitis, documenting changes in immunoinflammatory pathways and associated co-expression networks and their relationships to symptom scores out to 36 months. Results: Prior to immunotherapy, mite-induced Th-cell response networks involved multiple discrete co-expression modules including those related to Th2-, type1 IFN-, inflammation- and FOXP3/IL2-associated signalling. A signature comprising 109 genes correlated with symptom scores, and these mapped to cytokine signalling/T-cell activation-associated pathways, with upstream drivers including hallmark Th1/Th2- and inflammation-associated genes. Reanalysis after 3.5 months SCIT updosing detected minimal changes to pathway/upstream regulator profiles despite 32.5% symptom reduction; however, network analysis revealed underlying merging of FOXP3/IL2-with inflammation-and Th2-associated modules. By 12 months SCIT, symptoms had reduced by 41% without further significant changes to pathway/upstream regulator or network profiles. Continuing SCIT to 24 months stabilized symptoms at 47% of baseline, accompanied by upregulation of the type1 IFN-associated network module and its merging into the Th2/FOXP3/IL2/inflammation module. Conclusions: Subcutaneous immunotherapy stimulates progressive integration of mite-induced Th cell-associated Th2-, FOXP3/IL2-, inflammation- and finally type1 IFN-signalling subnetworks, forming a single highly integrated co-expression network module, maximizing potential for stable homeostatic control of allergen-induced Th2 responses via cross-regulation. Th2-antagonistic type1 IFN signalling may play a key role in stabilizing clinical effects of SCIT.
Project description:While several systemic immunomodulatory effects of allergen-specific immunotherapy (AIT) have been discovered, local anti-inflammatory mechanisms in the respiratory tract are largely unknown. We sought to elucidate local and epithelial mechanisms underlying allergen-specific immunotherapy in a genome-wide approach. We induced sputum in hay fever patients and healthy controls during the pollen peak season and stratified patients by effective allergen-immunotherapy or as untreated. Sputum was directly processed after induction and subjected to whole transcriptome RNA microarray analysis. Nasal secretions were analyzed for Secretoglobin1A1 (SCGB1A1) and IL-24 protein levels in an additional validation cohort at three defined time points during the three-year course of AIT. Subsequently, RNA was extracted and subjected to an array-based whole transcriptome analysis. AIT inhibited pro-inflammatory CXCL8, IL24 and CCL26 mRNA expression, while SCGB1A1, IL7, CCL5, CCL23 and WNT5B mRNAs were induced independently of the asthma status and allergen season. In our validation cohort, local increase of SCGB1A1 occurred concomitantly with the reduction of local IL-24 in upper airways during the course of AIT. Additionally, SCGB1A1 was identified as a suppressor of epithelial gene expression.AIT induces a yet unknown local gene expression footprint in the lower airways that on one hand appears to be a result of multiple regulatory pathways and on the other hand reveals SCGB1A1 as novel anti-inflammatory mediator of long-term allergen specific therapeutic intervention in the local environment.
Project description:Allergic rhinitis is a prevalent condition affecting up to 25% of the global population. Whilst common pharmacotherapies such as anti-histamines and corticosteroids can act as temporary symptom reliever, it does not work in 20% of patients. In these patients, allergen immunotherapy is recommended. The role of innate lymphoid cells in allergen specific immunotherapy which can result in the induction of tolerance towards the sensitizing allergen remains unclear. Using a combination of single cell RNA/protein and FACS validation, we provide evidence that the competence of ILC2 to produce IL-10 is dysregulated in allergic individuals and can be restored in patients who receive grass pollen immunotherapy. We also identified that this mechanism is associated with modification in retinol metabolic pathway, cytokine-cytokine receptor interaction and JAK-STAT signalling pathways in the ILCs.
Project description:Background: Airway epithelium in patients with allergic airway disease actively releases and is subjected to the influence of type-2 cytokines with observable changes in basal epithelial cells. Symptoms that grass pollen-allergic patients experience due to this priming can be controlled by allergen-specific immunotherapy (AIT). However, the impact of AIT on type-2 related mediators of airway epithelial cells is unknown. Methods: Protein levels of type-2 cytokines in nasal secretions of grass pollen-allergic patients were analyzed during 3-year AIT-regimen using multiplex-ELISA. Source and IL-4-dependence of type-2 cytokines were examined in IL-4-primed primary ALI cultures using single-cell transcriptomics. Results: Type-2 cytokines CCL-26 and POSTN oscillated seasonally, derived from basal epithelial cells and were induced by IL-4-priming. In contrast, TSLP and IL-33 derived from basal cells, albeit independently of IL-4. POSTN and IL-24 nasal levels changed corresponding to 3-year AIT progression. Four characteristic epithelial type-2 cytokines stood out: IL-33 changed independent of season, IL-4-exposure, or AIT; CCL-26 was triggered upon IL-4-priming and was induced during pollen season, but not influenced by AIT; IL-24 decreased following three years of AIT; and POSTN, which was increased in IL-4-primed basal epithelial cells and oscillated during pollen season, also responded to long-term AIT. Conclusions: Atopic reprogramming of type-2 epithelial cytokines seems to persist despite long-term AIT, which may be one mechanism explaining why AIT only restores allergen tolerance for seven to ten years. Type-2 related epithelial cytokines are differentially expressed which may relate to the distinct expression of basal as opposed to differentiated secretory or ciliated epithelial cells.
Project description:Immune checkpoint blockade has revolutionized cancer therapy. In particular, inhibition of programmed cell death protein 1 (PD-1) is effective for the treatment of metastatic melanoma and other cancers. Despite a dramatic increase in progression-free survival, a large proportion of patients do not show durable response. Therefore, predictive biomarkers of clinical response are urgently needed. Here, we employed high-dimensional single cell mass cytometry and a bioinformatics pipeline for the in-depth characterization of the immune cell subsets in the peripheral blood of metastatic melanoma patients before and after anti-PD-1 immunotherapy. During therapy, we observed a clear treatment response to immunotherapy in the T cell compartment. However, prior to commending therapy a strong predictor of progression free and overall survival in response to anti-PD-1 immunotherapy was the frequency of CD14+CD16-HLA-DRhi monocytes. We could confirm this by conventional flow cytometry in an independent validation cohort and propose this as a novel predictive biomarker for therapy decisions in the clinic. In order to determine whether there are cell intrinsic changes in the monocyte signature, we performed RNA sequencing on sorted CD14+CD16-HLA-DRhi cells from HD, NR and R at baseline. Representative samples (n=4, each) of responders/non responders/ and healthy donors were selected from archival samples stored in the dermatology biobank according to the same clinical criteria used in the discovery and validation cohorts for CyTOF and FACS analysis. CD14+CD16-HLA-DRhiLin- (CD3, CD4, CD19, CD45RO) monocytes were sorted from frozen PBMC form blood samples from HD, R and NR at baseline.