scholarly journals TREM-1+ Macrophages Define a Pathogenic Cell Subset in the Intestine of Crohn’s Disease Patients

Author(s):  
Charles Caër ◽  
Frida Gorreja ◽  
Sophia K Forsskåhl ◽  
Siggeir F Brynjolfsson ◽  
Louis Szeponik ◽  
...  

Abstract Background and Aims Uncontrolled activation of intestinal mononuclear phagocytes (MNPs) drives chronic inflammation in inflammatory bowel disease (IBD). Triggering receptor expressed on myeloid cells 1 (TREM-1) has been implicated in IBD pathogenesis. However, the role of TREM-1 + cell subsets in driving IBD pathology, and the link with clinical parameters, are not understood. We investigated TREM-1 expression in human intestinal MNP subsets and examined blocking TREM-1 as a potential IBD therapy. Methods TREM-1 gene expression was analysed in intestinal mucosa, enriched epithelial and lamina propria (LP) layers and purified cells from controls and IBD patients. TREM-1 protein on immune cells was assessed by flow cytometry and immunofluorescence microscopy. Blood monocyte activation was examined by large-scale gene expression using a TREM-1 agonist or LP conditioned media (LP-CM) from patients in the presence or absence of TREM-1 and TNF antagonist antibodies. Results TREM-1 gene expression increases in intestinal mucosa from IBD patients and correlates with the disease score. TREM-1 + cells, which are mainly immature macrophages and CD11b + granulocytes, increase among LP cells from Crohn’s patients and their frequency correlates with inflammatory molecules in LP-CM. LP-CM from Crohn’s patients induces an inflammatory transcriptome in blood monocytes, including increased IL-6 expression, which is reduced by simultaneous blocking of TREM-1 and TNF. Conclusions High intestinal TREM-1 expression, reflecting a high frequency of TREM-1 + immature macrophages and TREM-1 +CD11b + granulocytes, is linked to the deleterious inflammatory microenvironment in IBD patients. Therefore, blocking the TREM-1 pathway, especially simultaneously with anti-TNF therapy, has potential as a new IBD therapy.

2020 ◽  
Vol 9 (3) ◽  
pp. 86-93
Author(s):  
R. V. Ukrainets ◽  
Yu. S. Korneva ◽  
G. N. Alenina ◽  
N. V. Doronina

Reticuloendothelial system (RES) is considered one of the local immune response regulation centers. It takes part in most physiological and pathological processes, namely, in local homeostasis, in regulation of trophism and immunological responses of both primary and secondary immune responses. The main cell population of (RES) is a macrophage, which is a stationary cell that can move only within the tissue layer. Dendritic cells as representatives of (RES) as well are under direct control of macrophages. Up to 80% of all immunocompetent cells are concentrated in the intestinal mucosa. For adequate interaction with the intestinal microbiota and ensuring immunological tolerance to normal commensals, there is a lymphoid tissue associated with the intestinal mucosa (gut-associated lymphoid tissue – GALT), in which mononuclear phagocytes perform their most significant functions. When pathogenic microorganisms enter the mucosa, the network of resident macrophages as an immune barrier triggers an inflammatory response to further stabilize homeostasis. However, a pronounced microbial and antigenic load in the gut requires the mandatory presence of specific immune cells – lymphocytes, whose immature forms are located in GALT structures and specialize under the guidance of mononuclear phagocytes. After the final differentiation, lymphocytes expressing integrin α4β7 are able to return from the systemic bloodstream to the intestinal mucosa to perform highly specific functions. This phenomenon is called the homing effect. It was noted that in non-specific ulcerative colitis and Crohn's disease, both the number of regulatory T-lymphocytes and their expression of integrin α4β7 increases. The pathology of the homing effect, according to some researchers, explains the possibility of follow-up secondary lesions in chronic inflammatory bowel diseases with the development of systemic pathology.


Author(s):  
K. E. Muse ◽  
D. G. Fischer ◽  
H. S. Koren

Mononuclear phagocytes, a pluripotential cell line, manifest an array of basic extracellular functions. Among these physiological regulatory functions is the expression of spontaneous cytolytic potential against tumor cell targets.The limited observations on human cells, almost exclusively blood monocytes, initially reported limited or a lack of tumoricidal activity in the absence of antibody. More recently, freshly obtained monocytes have been reported to spontaneously impair the biability of tumor target cells in vitro (Harowitz et al., 1979; Montavani et al., 1979; Hammerstrom, 1979). Although the mechanism by which effector cells express cytotoxicity is poorly understood, discrete steps can be distinguished in the process of cell mediated cytotoxicity: recognition and binding of effector to target cells,a lethal-hit stage, and subsequent lysis of the target cell. Other important parameters in monocyte-mediated cytotoxicity include, activated state of the monocyte, effector cell concentrations, and target cell suseptibility. However, limited information is available with regard to the ultrastructural changes accompanying monocyte-mediated cytotoxicity.


2020 ◽  
Author(s):  
Lungwani Muungo

The purpose of this review is to evaluate progress inmolecular epidemiology over the past 24 years in canceretiology and prevention to draw lessons for futureresearch incorporating the new generation of biomarkers.Molecular epidemiology was introduced inthe study of cancer in the early 1980s, with theexpectation that it would help overcome some majorlimitations of epidemiology and facilitate cancerprevention. The expectation was that biomarkerswould improve exposure assessment, document earlychanges preceding disease, and identify subgroupsin the population with greater susceptibility to cancer,thereby increasing the ability of epidemiologic studiesto identify causes and elucidate mechanisms incarcinogenesis. The first generation of biomarkers hasindeed contributed to our understanding of riskandsusceptibility related largely to genotoxic carcinogens.Consequently, interventions and policy changes havebeen mounted to reduce riskfrom several importantenvironmental carcinogens. Several new and promisingbiomarkers are now becoming available for epidemiologicstudies, thanks to the development of highthroughputtechnologies and theoretical advances inbiology. These include toxicogenomics, alterations ingene methylation and gene expression, proteomics, andmetabonomics, which allow large-scale studies, includingdiscovery-oriented as well as hypothesis-testinginvestigations. However, most of these newer biomarkershave not been adequately validated, and theirrole in the causal paradigm is not clear. There is a needfor their systematic validation using principles andcriteria established over the past several decades inmolecular cancer epidemiology.


Gut ◽  
2020 ◽  
pp. gutjnl-2020-321731
Author(s):  
Dominik Aschenbrenner ◽  
Maria Quaranta ◽  
Soumya Banerjee ◽  
Nicholas Ilott ◽  
Joanneke Jansen ◽  
...  

ObjectiveDysregulated immune responses are the cause of IBDs. Studies in mice and humans suggest a central role of interleukin (IL)-23-producing mononuclear phagocytes in disease pathogenesis. Mechanistic insights into the regulation of IL-23 are prerequisite for selective IL-23 targeting therapies as part of personalised medicine.DesignWe performed transcriptomic analysis to investigate IL-23 expression in human mononuclear phagocytes and peripheral blood mononuclear cells. We investigated the regulation of IL-23 expression and used single-cell RNA sequencing to derive a transcriptomic signature of hyperinflammatory monocytes. Using gene network correlation analysis, we deconvolved this signature into components associated with homeostasis and inflammation in patient biopsy samples.ResultsWe characterised monocyte subsets of healthy individuals and patients with IBD that express IL-23. We identified autosensing and paracrine sensing of IL-1α/IL-1β and IL-10 as key cytokines that control IL-23-producing monocytes. Whereas Mendelian genetic defects in IL-10 receptor signalling induced IL-23 secretion after lipopolysaccharide stimulation, whole bacteria exposure induced IL-23 production in controls via acquired IL-10 signalling resistance. We found a transcriptional signature of IL-23-producing inflammatory monocytes that predicted both disease and resistance to antitumour necrosis factor (TNF) therapy and differentiated that from an IL-23-associated lymphocyte differentiation signature that was present in homeostasis and in disease.ConclusionOur work identifies IL-10 and IL-1 as critical regulators of monocyte IL-23 production. We differentiate homeostatic IL-23 production from hyperinflammation-associated IL-23 production in patients with severe ulcerating active Crohn’s disease and anti-TNF treatment non-responsiveness. Altogether, we identify subgroups of patients with IBD that might benefit from IL-23p19 and/or IL-1α/IL-1β-targeting therapies upstream of IL-23.


Author(s):  
Ekaterina Bourova-Flin ◽  
Samira Derakhshan ◽  
Afsaneh Goudarzi ◽  
Tao Wang ◽  
Anne-Laure Vitte ◽  
...  

Abstract Background Large-scale genetic and epigenetic deregulations enable cancer cells to ectopically activate tissue-specific expression programmes. A specifically designed strategy was applied to oral squamous cell carcinomas (OSCC) in order to detect ectopic gene activations and develop a prognostic stratification test. Methods A dedicated original prognosis biomarker discovery approach was implemented using genome-wide transcriptomic data of OSCC, including training and validation cohorts. Abnormal expressions of silent genes were systematically detected, correlated with survival probabilities and evaluated as predictive biomarkers. The resulting stratification test was confirmed in an independent cohort using immunohistochemistry. Results A specific gene expression signature, including a combination of three genes, AREG, CCNA1 and DDX20, was found associated with high-risk OSCC in univariate and multivariate analyses. It was translated into an immunohistochemistry-based test, which successfully stratified patients of our own independent cohort. Discussion The exploration of the whole gene expression profile characterising aggressive OSCC tumours highlights their enhanced proliferative and poorly differentiated intrinsic nature. Experimental targeting of CCNA1 in OSCC cells is associated with a shift of transcriptomic signature towards the less aggressive form of OSCC, suggesting that CCNA1 could be a good target for therapeutic approaches.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A38-A38
Author(s):  
Shilpa Ravindran ◽  
Heba Sidahmed ◽  
Harshitha Manjunath ◽  
Rebecca Mathew ◽  
Tanwir Habib ◽  
...  

BackgroundPatients with inflammatory bowel disease (IBD) have increased risk of developing colorectal cancer (CRC), depending on the duration and severity of the disease. The evolutionary process in IBD is driven by chronic inflammation leading to epithelial-to-mesenchymal transition (EMT) events in colonic fibrotic areas. EMT plays a determinant role in tumor formation and progression, through the acquisition of ‘stemness’ properties and the generation of neoplastic cells. The aim of this study is to monitor EMT/cancer initiating tracts in IBD in association with the deep characterization of inflammation in order to assess the mechanisms of IBD severity and progression towards malignancy.Methods10 pediatric and 20 adult IBD patients, admitted at Sidra Medicine (SM) and Hamad Medical Corporation (HMC) respectively, have been enrolled in this study, from whom gut tissue biopsies (from both left and right side) were collected. Retrospectively collected tissues (N=10) from patients with malignancy and history of IBD were included in the study. DNA and RNA were extracted from fresh small size (2–4 mm in diameter) gut tissues using the BioMasher II (Kimble) and All Prep DNA/RNA kits (Qiagen). MicroRNA (miRNA; N=700) and gene expression (N=800) profiling have been performed (cCounter platform; Nanostring) as well as the methylation profiling microarray (Infinium Methylation Epic Bead Chip kit, Illumina) to interrogate up to 850,000 methylation sites across the genome.ResultsDifferential miRNA profile (N=27 miRNA; p<0.05) was found by the comparison of tissues from pediatric and adult patients. These miRNAs regulate: i. oxidative stress damage (e.g., miR 99b), ii. hypoxia induced autophagy; iii. genes associated with the susceptibility to IBD (ATG16L1, NOD2, IRGM), iv. immune responses, such as TH17 T cell subset (miR 29). N=6 miRNAs (miR135b, 10a196b, 125b, let7c, 375) linked with the regulation of Wnt/b-catenin, EM-transaction, autophagy, oxidative stress and play role also in cell proliferation and mobilization and colorectal cancer development were differentially expressed (p<0.05) in tissues from left and right sides of gut. Gene expression signature, including genes associated with inflammation, stemness and fibrosis, has also been performed for the IBD tissues mentioned above. Methylation sites at single nucleotide resolution have been analyzed.ConclusionsAlthough the results warrant further investigation, differential genomic profiling suggestive of altered pathways involved in oxidative stress, EMT, and of the possible stemness signature was found. The integration of data from multiple platforms will provide insights of the overall molecular determinants in IBD patients along with the evolution of the disease.Ethics ApprovalThis study was approved by Sidra Medicine and Hamad Medical Corporation Ethics Boards; approval number 180402817 and MRC-02-18-096, respectively.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ashley A. Krull ◽  
Deborah O. Setter ◽  
Tania F. Gendron ◽  
Sybil C. L. Hrstka ◽  
Michael J. Polzin ◽  
...  

Abstract Background Mesenchymal stromal cells (MSCs) have been studied with increasing intensity as clinicians and researchers strive to understand the ability of MSCs to modulate disease progression and promote tissue regeneration. As MSCs are used for diverse applications, it is important to appreciate how specific physiological environments may stimulate changes that alter the phenotype of the cells. One need for neuroregenerative applications is to characterize the spectrum of MSC responses to the cerebrospinal fluid (CSF) environment after their injection into the intrathecal space. Mechanistic understanding of cellular biology in response to the CSF environment may predict the ability of MSCs to promote injury repair or provide neuroprotection in neurodegenerative diseases. Methods In this study, we characterized changes in morphology, metabolism, and gene expression occurring in human adipose-derived MSCs cultured in human (hCSF) or artificial CSF (aCSF) as well as examined relevant protein levels in the CSF of subjects treated with MSCs for amyotrophic lateral sclerosis (ALS). Results Our results demonstrated that, under intrathecal-like conditions, MSCs retained their morphology, though they became quiescent. Large-scale transcriptomic analysis of MSCs revealed a distinct gene expression profile for cells cultured in aCSF. The aCSF culture environment induced expression of genes related to angiogenesis and immunomodulation. In addition, MSCs in aCSF expressed genes encoding nutritional growth factors to expression levels at or above those of control cells. Furthermore, we observed a dose-dependent increase in growth factors and immunomodulatory cytokines in CSF from subjects with ALS treated intrathecally with autologous MSCs. Conclusions Overall, our results suggest that MSCs injected into the intrathecal space in ongoing clinical trials remain viable and may provide a therapeutic benefit to patients.


2021 ◽  
Vol 22 (12) ◽  
pp. 6394
Author(s):  
Jacob Spinnen ◽  
Lennard K. Shopperly ◽  
Carsten Rendenbach ◽  
Anja A. Kühl ◽  
Ufuk Sentürk ◽  
...  

For in vitro modeling of human joints, osteochondral explants represent an acceptable compromise between conventional cell culture and animal models. However, the scarcity of native human joint tissue poses a challenge for experiments requiring high numbers of samples and makes the method rather unsuitable for toxicity analyses and dosing studies. To scale their application, we developed a novel method that allows the preparation of up to 100 explant cultures from a single human sample with a simple setup. Explants were cultured for 21 days, stimulated with TNF-α or TGF-β3, and analyzed for cell viability, gene expression and histological changes. Tissue cell viability remained stable at >90% for three weeks. Proteoglycan levels and gene expression of COL2A1, ACAN and COMP were maintained for 14 days before decreasing. TNF-α and TGF-β3 caused dose-dependent changes in cartilage marker gene expression as early as 7 days. Histologically, cultures under TNF-α stimulation showed a 32% reduction in proteoglycans, detachment of collagen fibers and cell swelling after 7 days. In conclusion, thin osteochondral slice cultures behaved analogously to conventional punch explants despite cell stress exerted during fabrication. In pharmacological testing, both the shorter diffusion distance and the lack of need for serum in the culture suggest a positive effect on sensitivity. The ease of fabrication and the scalability of the sample number make this manufacturing method a promising platform for large-scale preclinical testing in joint research.


Sign in / Sign up

Export Citation Format

Share Document