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Hendriks, R. W.

Publications and source records attributed to Hendriks, R. W..

5 recordsLinked to original sources

Common γ-chain cytokines induce an epigenomically plastic precursor-like KIT+ ILC2 state linked to immune disease susceptibility

BackgroundGroup 2 innate lymphoid cells (ILC2s) are key effector cells of type-2 immunity. A subset of ILC2s expresses KIT (CD117), which display increased phenotypic plasticity and were previously linked to severe asthma and psoriasis. However, the molecular mechanisms promoting a KIT+ ILC2 state remain poorly understood. ObjectiveDefine the molecular basis for the enhanced plasticity of KIT+ ILC2s and identify signals that induce this phenotype, including links with immune disease susceptibility. MethodsWe combine bulk as well as single-cell transcriptome (RNA-seq) and epigenome (ATAC-seq) with in vitro culture assays using primary human KIT+ or KITneg ILC2s and multipotent ILC precursors (ILCPs). Epigenomic data were integrated with genetic risk variants for major human immune diseases. ResultsMulti-omics analyses revealed that KIT+ ILC2s maintain a unique hybrid character marked by expression and open chromatin of genes linked to both ILCP and ILC2 biology. KIT+ ILC2s showed extensive epigenomic priming at gene loci related to naive lymphocyte biology, tissue homing, and ILC3 effector functions, including IL17 and IL23R - explaining why KIT+ ILC2s are poised to adopt an ILC3-like phenotype. Genetic risk variants for asthma and autoimmunity are enriched in the poised epigenome of KIT+ ILC2s. Common {gamma}-chain cytokines IL-2 and IL-7 induced a KIT+ phenotype in KITneg ILC2s through STAT5 activation. ConclusionsOur study defines KIT+ ILC2s as a developmentally immature state carrying a precursor-like epigenome that promotes phenotypic plasticity and is linked to immune disease susceptibility. Importantly, we identify STAT5-mediated cytokine signals as candidates for therapeutic targeting of KIT+ ILC2s.

immunology↗

Airway epithelial response to RSV is impaired in multiciliated and goblet cells in asthma

In patients with asthma, respiratory syncytial virus (RSV) infections can cause disease exacerbations by infecting the epithelial layer of the airways, inducing an innate and adaptive immune response. The type-I interferon antiviral response of epithelial cells upon RSV infection is found to be reduced in asthma in most -but not all-studies. Moreover, the molecular mechanisms that cause the differences in the asthmatic bronchial epithelium in response to viral infection are poorly understood. Here, we investigated the transcriptional response to RSV infection of primary bronchial epithelial cells (pBECs) from asthma patients(n=8) and healthy donors(n=8). The pBECs obtained from bronchial brushes were differentiated in air-liquid interface conditions and infected with RSV. After three days, cells were processed for single-cell RNA sequencing. A strong antiviral response to RSV was observed for all cell types present, from both asthma patients and healthy donors. Most differentially regulated genes following RSV infection were found in cells transitioning from basal to secretory. Goblet cells from asthma patients showed lower expression of genes involved in the interferon response. In multiciliated cells, an impairment of the signaling pathways involved in the response to RSV in asthma was observed, including no enrichment of the type-III interferon response. Our results highlight that the response to RSV infection of the bronchial epithelium in asthma and healthy airways was largely similar. However, in asthma, the response of goblet and the multiciliated cells was impaired, highlighting the need for studying airway epithelial cells at high resolution in the context of asthma exacerbations. What is already know on this topicThe airway epithelium response to RSV is altered in asthma. However, literature remains conflicted about the exact changes in the antiviral response, and the mechanisms causing these changes are yet to be found. What this study addsThis study describes extensively the response of the bronchial epithelial cells (BECs) to RSV for both healthy subjects and asthma patients, at a single-cell resolution. It highlights the major overlap between healthy and asthma in the antiviral response to RSV. It allows the identification of specific genes and cell types that show a different behavior in response to RSV in asthma compared to healthy. How this study might affect research, practice or policyOur study indicates that goblet and multiciliated cells are the most relevant BECs to further investigate in the context of drug development for RSV-induced asthma exacerbation. It also suggests that focusing research on the cross-talk between the epithelial and the immune cells, or into investigating a potential delayed response in asthma would be the best way forward into understanding the mechanisms involved in the asthma response to RSV.

molecular biology↗

FastCAR: Fast Correction for Ambient RNA to facilitate differential gene expression analysis in single-cell RNA-sequencing datasets

Cell type-specific differential gene expression analyses based on single-cell transcriptome datasets are sensitive to the presence of cell-free mRNA in the droplets containing single cells. This so-called ambient RNA contamination may differ between samples obtained from patients and healthy controls. Current ambient RNA correction methods were not developed specifically for single-cell differential gene expression (sc-DGE) analyses and might therefore not sufficiently correct for ambient RNA-derived signals. Here, we show that ambient RNA levels are highly sample-specific. We found that without ambient RNA correction, sc-DGE analyses erroneously identify transcripts originating from ambient RNA as cell type-specific disease-associated genes. We therefore developed a computationally lean and intuitive correction method, Fast Correction for Ambient RNA (FastCAR), optimized for sc-DGE analysis of scRNA-Seq datasets generated by droplet-based methods including the 10XGenomics Chromium platform. FastCAR uses the profile of transcripts observed in libraries that likely represent empty droplets to determine the level of ambient RNA in each individual sample, and then corrects for these ambient RNA gene expression values. FastCAR can be applied as part of the data pre-processing and QC in sc-DGE workflows comparing scRNA-Seq data in a health versus disease experimental design. We compared FastCAR with two methods previously developed to remove ambient RNA, SoupX and CellBender. All three methods identified additional genes in sc-DGE analyses that were not identified in the absence of ambient RNA correction. However, we show that FastCAR performs better at correcting gene expression values attributed to ambient RNA, resulting in a lower frequency of false-positive observations. Moreover, the use of FastCAR in a sc-DGE workflow increases the cell-type specificity of sc-DGE analyses across disease conditions.

bioinformatics↗

CCR1 regulatory variants linked to pulmonary macrophage recruitment in severe COVID-19

Genome-wide association studies have identified 3p21.31 as the main risk locus for severe disease in COVID-19 patients, although underlying biological mechanisms remain elusive. We performed a comprehensive epigenomic dissection of the 3p21.31 locus, identifying a CTCF-dependent tissue-specific 3D regulatory chromatin hub that controls the activity of several tissue-homing chemokine receptor (CCR) genes in monocytes and macrophages. Risk SNPs colocalized with regulatory elements and were linked to increased expression of CCR1, CCR2 and CCR5 in monocytes and macrophages. As excessive organ infiltration of inflammatory monocytes and macrophages is a hallmark of severe COVID-19, our findings provide a rationale for the genetic association of 3p21.31 variants with elevated risk of hospitalization upon SARS-CoV-2 infection.

immunology↗

SIRPalpha on mouse B1 cells restricts lymphoid tissue migration and natural antibody production

The inhibitory immunoreceptor SIRP is expressed on myeloid and neuronal cells and interacts with the broadly expressed CD47. CD47-SIRP interactions form an innate immune checkpoint and its targeting has shown promising results in cancer patients. Here, we report expression of SIRP on B1 lymphocytes, a non-conventional subpopulation of murine B cells responsible for the production of natural antibodies. Mice defective in SIRP signaling (SIRP{Delta}CYT mice) displayed an enhanced CD11b/CD18 integrin-dependent B1 cell migration from the peritoneal cavity to the spleen, local B1 cell accumulation, and enhanced circulating natural antibody levels, which was further amplified upon immunization with T-independent type 2 antigen. As natural antibodies are atheroprotective we investigated the involvement of SIRP signaling in atherosclerosis development. Bone marrow (SIRP{Delta}CYT>LDLR-/-) chimaeric mice developed reduced atherosclerosis accompanied by increased natural antibody production. Collectively, our data identify SIRP as a unique B1 cell inhibitory receptor acting to control B1 cell migration, and imply SIRP as a potential therapeutic target in atherosclerosis.

immunology↗