scholarly journals Integrating Mendelian randomization and multiple-trait colocalization to uncover cell-specific inflammatory drivers of autoimmune and atopic disease

2018 ◽  
Author(s):  
Lucy M. McGowan ◽  
George Davey Smith ◽  
Tom R. Gaunt ◽  
Tom G. Richardson

AbstractImmune mediated diseases (IMDs) arise from a lack of immune tolerance, causing chronic inflammation. Despite their growing prevalence, targeted therapies to treat IMDs are lacking. Cytokines and their receptors, which mediate inflammation, have been associated with IMD susceptibility. However, the complex signalling networks and multiple cell-types required to orchestrate inflammatory responses have made it difficult to pinpoint specific cytokines and immune cell-types which drive IMDs.In this study, we developed an analytical framework which integrates Mendelian randomisation (MR) and multiple-trait colocalization (moloc) analyses to determine putative cell-specific drivers of IMDs. We used MR to determine the likelihood of causal associations between the levels of 10 circulating cytokines/cytokine receptors and 9 IMDs within human populations of European descent. Conservative (single SNP) and liberal (multiple SNP) MR analysis supported a causal role for IL-18 in inflammatory bowel disease (P = 1.17 × 10−4) and eczema/dermatitis (P = 2.81 × 10−3), as well as roles for IL-2rα and IL-6R in several IMDs.Where associations between cytokines/cytokine receptors and IMDs were discovered using MR, we undertook moloc analyses. This was to assess the likelihood that cytokine/cytokine receptor protein quantitative trait loci (pQTL) and IMD-associated loci share a causal genetic variant along with expression QTL (eQTL) using data from 3 immune cell-types: monocytes, neutrophils and T cells. We found a monocyte and neutrophil-driven role for IL-18 in IBD pathogenesis, amongst evidence supporting several other cell-specific inflammatory drivers of IMDs. Our study helps to elucidate causal pathways for the pathogeneses of IMDs which, together with other studies, highlights possible therapeutic targets for their treatment.

2019 ◽  
Vol 28 (19) ◽  
pp. 3293-3300 ◽  
Author(s):  
Lucy M McGowan ◽  
George Davey Smith ◽  
Tom R Gaunt ◽  
Tom G Richardson

Abstract Immune-mediated diseases (IMDs) arise when tolerance is lost and chronic inflammation is targeted towards healthy tissues. Despite their growing prevalence, therapies to treat IMDs are lacking. Cytokines and their receptors orchestrate inflammatory responses by regulating elaborate signalling networks across multiple cell types making it challenging to pinpoint therapeutically relevant drivers of IMDs. We developed an analytical framework that integrates Mendelian randomization (MR) and multiple-trait colocalization (moloc) analyses to highlight putative cell-specific drivers of IMDs. MR evaluated causal associations between the levels of 10 circulating cytokines and 9 IMDs within human populations. Subsequently, we undertook moloc analyses to assess whether IMD trait, cytokine protein and corresponding gene expression are driven by a shared causal variant. Moreover, we leveraged gene expression data from three separate cell types (monocytes, neutrophils and T cells) to discern whether associations may be attributed to cell type-specific drivers of disease. MR analyses supported a causal role for IL-18 in inflammatory bowel disease (IBD) (P = 1.17 × 10−4) and eczema/dermatitis (P = 2.81 × 10−3), as well as associations between IL-2rα and IL-6R with several other IMDs. Moloc strengthened evidence of a causal association for these results, as well as providing evidence of a monocyte and neutrophil-driven role for IL-18 in IBD pathogenesis. In contrast, IL-2rα and IL-6R associations were found to be T cell specific. Our analytical pipeline can help to elucidate putative molecular pathways in the pathogeneses of IMDs, which could be applied to other disease contexts.


Endocrinology ◽  
2015 ◽  
Vol 157 (2) ◽  
pp. 900-912 ◽  
Author(s):  
Yuechao Zhao ◽  
Yiru Chen ◽  
Ye Kuang ◽  
Milan K. Bagchi ◽  
Robert N. Taylor ◽  
...  

Abstract Endometriosis is an estrogen-dependent, inflammation-driven gynecologic disorder in which endometrial tissue creates inflammatory lesions at extrauterine sites, leading to pelvic pain and impaired fertility. Although dysregulated estrogen receptor (ER) signaling has been implicated, understanding of this disease is incomplete and current therapies are of limited benefit. Using an immunocompetent syngeneic murine model, we used combinations of donor uterine tissue and/or recipient host mice with partial genetic deletion of the ER coregulator, repressor of ER activity (REA) (also known as prohibitin 2), to investigate roles of REA in the contributions of donor uterine tissue and host cell influences on endometriosis establishment and progression. Ectopic lesions derived from donor tissue with half the wild-type gene dosage of REA (REA+/−) grown in REA+/− hosts displayed enhanced proliferation, vascularization, and markedly increased neuron innervation and inflammatory responses, including elevated cytokine production, nuclear factor kappa B activation, cyclooxygenase-2 expression, and immune cell infiltration. Although lesion progression was greatest when REA was reduced in both donor tissue and host animals, other donor/host combinations indicated that distinct stimulatory inputs were derived from ectopic tissue (proliferative signals) and host cells (inflammatory signals). Importantly, depletion of REA in primary human endometriotic stromal cells led to elevated proliferation and expression of cell cycle regulators. Notably, REA was significantly lower in human endometriotic tissue versus normal human endometrium. Thus, REA modulates cross talk among multiple cell types in the uterine tissue and host background, serving as a brake on the estradiol-ER axis and restraining multiple aspects that contribute to the pathologic progression of endometriosis.


2021 ◽  
Vol 3 (Supplement_2) ◽  
pp. ii14-ii14
Author(s):  
Michael Schulz ◽  
Tijna Alekseeva ◽  
Julian Anthes ◽  
Jandranka Macas ◽  
Birgitta Michels ◽  
...  

Abstract Macrophages represent a highly plastic cell type,indispensable for tissue and organ homeostasis, as well as innate immunity. Basic and translational research attributed tumor-promoting functions to macrophages, and their presence is often associated to poor patient prognosis and therapy resistance. While brain-resident macrophages, the so-called microglia (MG), represent the major immune cell type in the parenchyma under normal conditions, primary and metastatic brain tumors induce the recruitment of different immune cell types from the periphery, including monocyte-derived macrophages (MDM). Controversy remained about the redundancy of disease-associated molecular signatures and functions. The identification of markers that reliably distinguish brain-resident from blood-borne tumor-associated macrophages (TAMs) allowed the interrogation of molecular traits of different TAM populations in mouse and human brain tumors. Using RNA-Seq, we demonstrated that TAMs rapidly acquire disease-associated transcriptional programs upon initial tumor infiltration, while gene expression remained stable during different stages of BrM progression. Across different BrM models, disease-associated transcriptional changes revealed lineage-specific, non-redundant functions of TAM populations, which was further reflected by cell type-specific occupation of different niches within the BrM microenvironment. Furthermore, we observed dose- and cell type-specific immune modulatory effects of whole brain radiotherapy on myeloid cells in BrM leading to a transient loss of disease-associated transcriptional programs predominately in blood-borne myeloid populations. This effect can at least in part be attributed to a replenishment of the recruited macrophage pool. This observation was further supported by scRNA-Seq analyses revealing higher heterogeneity of TAM-MDM compared to TAM-MG under treatment-naïve conditions and in response to radiotherapy. Together, our results point towards the phenotypic plasticity of TAMs, especially MDMs, and the contribution of each compartment in instigating cancer-associated inflammation or the establishment of an immuno-suppressive TME. While TAM-MG exert functions related to pro-inflammatory responses, TAM-MDM are rather involved in tissue repair and regulation of adaptive immune cell functions.


1999 ◽  
Vol 340 (1) ◽  
pp. 153-159 ◽  
Author(s):  
Jun ZOU ◽  
Norman F. NEUMANN ◽  
Jason W. HOLLAND ◽  
Miodrag BELOSEVIC ◽  
Charles CUNNINGHAM ◽  
...  

In mammals, the increased generation of prostaglandins (PG) during the onset of inflammatory responses and activation of immune cell types has been attributed to the induction of a novel cyclo-oxygenase (COX) isoform, termed COX-2, which is distinct from the well-characterized constitutive activity (COX-1). Goldfish (Carassius auratus) macrophages exposed to bacterial lipopolysaccharide and leucocyte-derived macrophage-activating factor(s) showed a significant increase in the generation of the major COX product, PGE2, within the first 6 h of stimulation. The selective COX-2 inhibitor, NS398, inhibited this elevated generation of PGE, whereas the basal level of this product synthesized by unstimulated macrophages was unaffected by such exposure. PGE generation by goldfish macrophages was similarly inhibited by the glucocorticoid, dexamethasone, and an inhibitor of protein synthesis, cycloheximide, suggesting that this stimulation may be due to an inducible enzyme equivalent to mammalian COX-2. The complete coding sequence of rainbow trout (Oncorhynchus mykiss) COX-2 was obtained by PCR. The gene contains a 61 bp 5ʹ-untranslated region (UTR), a 1821 bp open reading frame and a 771 bp 3ʹUTR containing multiple copies of an mRNA instability motif (ATTTA). The predicted translation product had high homology to known mammalian and chicken COX-2 (83-84%) and COX-1 (77%) sequences. Reverse-transcriptase PCR with cDNA from control and bacterially challenged fish revealed that trout COX-2 expression was not constitutive but could be induced. Overall, these studies show for the first time that the inducible isoform of COX has a long evolutionary history, probably dating back to the evolution of fish over 500 million years ago.


2006 ◽  
Vol 26 (9) ◽  
pp. 3505-3513 ◽  
Author(s):  
Lixin Zheng ◽  
Nicolas Bidere ◽  
David Staudt ◽  
Alan Cubre ◽  
Jan Orenstein ◽  
...  

ABSTRACT Stimulation of tumor necrosis factor receptor 1 (TNFR1) can initiate several cellular responses, including apoptosis, which relies on caspases, necrotic cell death, which depends on receptor-interacting protein kinase 1 (RIP1), and NF-κB activation, which induces survival and inflammatory responses. The TNFR-associated death domain (TRADD) protein has been suggested to be a crucial signal adaptor that mediates all intracellular responses from TNFR1. However, cells with a genetic deficiency of TRADD are unavailable, precluding analysis with mature immune cell types. We circumvented this problem by silencing TRADD expression with small interfering RNA. We found that TRADD is required for TNFR1 to induce NF-κB activation and caspase-8-dependent apoptosis but is dispensable for TNFR1-initiated, RIP1-dependent necrosis. Our data also show that TRADD and RIP1 compete for recruitment to the TNFR1 signaling complex and the distinct programs of cell death. Thus, TNFR1-initiated intracellular signals diverge at a very proximal level by the independent association of two death domain-containing proteins, RIP1 and TRADD. These single transducers determine cell fate by triggering NF-κB activation, apoptosis, and nonapoptotic death signals through separate and competing signaling pathways.


2021 ◽  
Vol 22 (15) ◽  
pp. 8042
Author(s):  
Mengmeng Jin ◽  
Katja Akgün ◽  
Tjalf Ziemssen ◽  
Markus Kipp ◽  
Rene Günther ◽  
...  

Amyotrophic lateral sclerosis (ALS) is a progressive disease leading to the degeneration of motor neurons (MNs). Neuroinflammation is involved in the pathogenesis of ALS; however, interactions of specific immune cell types and MNs are not well studied. We recently found a shift toward T helper (Th)1/Th17 cell-mediated, pro-inflammatory immune responses in the peripheral immune system of ALS patients, which positively correlated with disease severity and progression. Whether Th17 cells or their central mediator, Interleukin-17 (IL-17), directly affects human motor neuron survival is currently unknown. Here, we evaluated the contribution of Th17 cells and IL-17 on MN degeneration using the co-culture of iPSC-derived MNs of fused in sarcoma (FUS)-ALS patients and isogenic controls with Th17 lymphocytes derived from ALS patients, healthy controls, and multiple sclerosis (MS) patients (positive control). Only Th17 cells from MS patients induced severe MN degeneration in FUS-ALS as well as in wildtype MNs. Their main effector, IL-17A, yielded in a dose-dependent decline of the viability and neurite length of MNs. Surprisingly, IL-17F did not influence MNs. Importantly, neutralizing IL-17A and anti-IL-17 receptor A treatment reverted all effects of IL-17A. Our results offer compelling evidence that Th17 cells and IL-17A do directly contribute to MN degeneration.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Stephan Hailfinger ◽  
Klaus Schulze-Osthoff

Abstract Psoriasis is a frequent autoimmune-related skin disease, which involves various cell types such as T cells, keratinocytes and dendritic cells. Genetic variations, such as mutations of CARD14, can promote the development of the disease. CARD14 mutations as well as the stimulation of immune and cytokine receptors activate the paracaspase MALT1, a potent activator of the transcription factors NF-κB and AP-1. The disease-promoting role of MALT1 for psoriasis is mediated by both its protease activity as well as its molecular scaffold function. Here, we review the importance of MALT1-mediated signaling and its therapeutic implications in psoriasis.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Wiruntita Chankeaw ◽  
Sandra Lignier ◽  
Christophe Richard ◽  
Theodoros Ntallaris ◽  
Mariam Raliou ◽  
...  

Abstract Background A number of studies have examined mRNA expression profiles of bovine endometrium at estrus and around the peri-implantation period of pregnancy. However, to date, these studies have been performed on the whole endometrium which is a complex tissue. Consequently, the knowledge of cell-specific gene expression, when analysis performed with whole endometrium, is still weak and obviously limits the relevance of the results of gene expression studies. Thus, the aim of this study was to characterize specific transcriptome of the three main cell-types of the bovine endometrium at day-15 of the estrus cycle. Results In the RNA-Seq analysis, the number of expressed genes detected over 10 transcripts per million was 6622, 7814 and 8242 for LE, GE and ST respectively. ST expressed exclusively 1236 genes while only 551 transcripts were specific to the GE and 330 specific to LE. For ST, over-represented biological processes included many regulation processes and response to stimulus, cell communication and cell adhesion, extracellular matrix organization as well as developmental process. For GE, cilium organization, cilium movement, protein localization to cilium and microtubule-based process were the only four main biological processes enriched. For LE, over-represented biological processes were enzyme linked receptor protein signaling pathway, cell-substrate adhesion and circulatory system process. Conclusion The data show that each endometrial cell-type has a distinct molecular signature and provide a significantly improved overview on the biological process supported by specific cell-types. The most interesting result is that stromal cells express more genes than the two epithelial types and are associated with a greater number of pathways and ontology terms.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Rongqun Guo ◽  
Mengdie Lü ◽  
Fujiao Cao ◽  
Guanghua Wu ◽  
Fengcai Gao ◽  
...  

Abstract Background Knowledge of immune cell phenotypes, function, and developmental trajectory in acute myeloid leukemia (AML) microenvironment is essential for understanding mechanisms of evading immune surveillance and immunotherapy response of targeting special microenvironment components. Methods Using a single-cell RNA sequencing (scRNA-seq) dataset, we analyzed the immune cell phenotypes, function, and developmental trajectory of bone marrow (BM) samples from 16 AML patients and 4 healthy donors, but not AML blasts. Results We observed a significant difference between normal and AML BM immune cells. Here, we defined the diversity of dendritic cells (DC) and macrophages in different AML patients. We also identified several unique immune cell types including T helper cell 17 (TH17)-like intermediate population, cytotoxic CD4+ T subset, T cell: erythrocyte complexes, activated regulatory T cells (Treg), and CD8+ memory-like subset. Emerging AML cells remodels the BM immune microenvironment powerfully, leads to immunosuppression by accumulating exhausted/dysfunctional immune effectors, expending immune-activated types, and promoting the formation of suppressive subsets. Conclusion Our results provide a comprehensive AML BM immune cell census, which can help to select pinpoint targeted drug and predict efficacy of immunotherapy.


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