19 research outputs found

    Rewiring of the TCR signalosome in natural intestinal Intraepithelial T lymphocytes drives non-deletional tolerance

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    Intraepithelial T lymphocytes (T-IEL) are a large population of cytotoxic T cells that protect the small intestinal epithelium against pathogens. Based on ontogeny, T-IEL can be categorized into two major subsets: induced and natural. Natural T-IEL are agonistically selected in the thymus on self-antigens before migrating directly to the small intestine. Despite having self-reactive T cell antigen receptors (TCR), natural T-IEL are maintained in a tolerized state in the gut by unknown mechanisms. We therefore investigated TCR signaling in T-IEL using multiplexed fluorescent cell barcoding, phosphoproteomics and TCR signaling reporter mouse models, which revealed that TCR signaling is intrinsically suppressed in natural, but not induced, T-IEL. Unexpectedly, we discover that this cell intrinsic suppression was mediated through altered TCR signalosome components. Specifically, downregulation of the key signaling adaptor, Linker for activation of T cells (LAT) during thymic selection is a vital checkpoint for the development and tolerization of natural IELs. Thus, TCR signaling is rewired in self-reactive natural T-IEL to promote tolerance and prevent inappropriate inflammation in the gut.One sentence summary Self-reactive natural intestinal intraepithelial T lymphocytes are developmentally tolerized by rewiring the T cell antigen receptor signaling pathway through the downregulation of the adaptor protein, LAT

    Rewiring of the TCR signalosome in natural intestinal Intraepithelial T lymphocytes drives non-deletional tolerance

    Get PDF
    Intraepithelial T lymphocytes (T-IEL) are a large population of cytotoxic T cells that protect the small intestinal epithelium against pathogens. Based on ontogeny, T-IEL can be categorized into two major subsets: induced and natural. Natural T-IEL are agonistically selected in the thymus on self-antigens before migrating directly to the small intestine. Despite having self-reactive T cell antigen receptors (TCR), natural T-IEL are maintained in a tolerized state in the gut by unknown mechanisms. We therefore investigated TCR signaling in T-IEL using multiplexed fluorescent cell barcoding, phosphoproteomics and TCR signaling reporter mouse models, which revealed that TCR signaling is intrinsically suppressed in natural, but not induced, T-IEL. Unexpectedly, we discover that this cell intrinsic suppression was mediated through altered TCR signalosome components. Specifically, downregulation of the key signaling adaptor, Linker for activation of T cells (LAT) during thymic selection is a vital checkpoint for the development and tolerization of natural IELs. Thus, TCR signaling is rewired in self-reactive natural T-IEL to promote tolerance and prevent inappropriate inflammation in the gut.One sentence summary Self-reactive natural intestinal intraepithelial T lymphocytes are developmentally tolerized by rewiring the T cell antigen receptor signaling pathway through the downregulation of the adaptor protein, LAT

    Tissue environment, not ontogeny, defines murine intestinal intraepithelial T lymphocytes

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    Tissue-resident intestinal intraepithelial T lymphocytes (T-IEL) patrol the gut and have important roles in regulating intestinal homeostasis. T-IEL include both induced T-IEL, derived from systemic antigen-experienced lymphocytes, and natural T-IEL, which are developmentally targeted to the intestine. While the processes driving T-IEL development have been elucidated, the precise roles of the different subsets and the processes driving activation and regulation of these cells remain unclear. To gain functional insights into these enigmatic cells, we used high-resolution, quantitative mass spectrometry to compare the proteomes of induced T-IEL and natural T-IEL subsets, with naive CD8(+) T cells from lymph nodes. This data exposes the dominant effect of the gut environment over ontogeny on T-IEL phenotypes. Analyses of protein copy numbers of >7000 proteins in T-IEL reveal skewing of the cell surface repertoire towards epithelial interactions and checkpoint receptors; strong suppression of the metabolic machinery indicating a high energy barrier to functional activation; upregulated cholesterol and lipid metabolic pathways, leading to high cholesterol levels in T-IEL; suppression of T cell antigen receptor signalling and expression of the transcription factor TOX, reminiscent of chronically activated T cells. These novel findings illustrate how T-IEL integrate multiple tissue-specific signals to maintain their homeostasis and potentially function

    Acupuncture, Counseling, and Usual care for Depression (ACUDep): study protocol for a randomized controlled trial

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    Background: The evidence on the effect of acupuncture or counseling for depression is not conclusive yet is sufficient to warrant further research. Our aim is to conduct a full-scale RCT to determine the clinical and cost effectiveness of acupuncture and counseling compared to usual care alone. We will explore the experiences and perspectives of patients and practitioners. Methods/Design: Randomized controlled trial with three parallel arms: acupuncture plus usual care, counseling plus usual care, and usual care alone, in conjunction with a nested qualitative study using in-depth interviews with purposive samples of trial participants. Participants: Patients aged over 18 years diagnosed with depression or mood disorder by their GP and with a score of 20 or above on the Beck Depression Inventory (BDI-II). Randomization: Computer randomization by York Trials Unit to acupuncture, counseling, and usual care alone in proportions of 2:2:1, respectively, with secure allocation concealment. Interventions: Patients allocated to acupuncture and counseling groups receive the offer of up to 12 weekly sessions. Both interventions allow flexibility to address patient variation, yet are constrained within defined protocols. Acupuncture is based on traditional Chinese medicine and counseling is non-directive within the humanistic tradition. Outcome: The PHQ-9 is the primary outcome measure, collected at baseline, 3, 6, 9, and 12 months. Also measured is BDI-II, SF-36 Bodily pain subscale, and EQ-5D. Texted mood scores are collected weekly over the first 15 weeks. Health-related resource use is collected over 12 months. Analysis: The sample size target was for 640 participants, calculated for an effect size of 0.32 on the PHQ-9 when comparing acupuncture with counseling given 90% power, 5% significance, and 20% loss to follow-up. Analysis of covariance will be used on an intention-to-treat basis. Thematic analysis will be used for qualitative data. We will compare incremental cost-effectiveness of the three treatment options at 12 months. Discussion: Ethical approval was obtained in October 2009. There were six subsequent protocol amendments, the last of which was approved in January 2012. Recruitment of 755 participants took place over 18 months. Data collection will be completed by June 2012. No interim analyses have been conducted

    Environmental exposures and their genetic or environmental contribution to depression and fatigue: a twin study in Sri Lanka

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    Background There is very little genetically informative research identifying true environmental risks for psychiatric conditions. These may be best explored in regions with diverse environmental exposures. The current study aimed to explore similarities and differences in such risks contributing to depression and fatigue. Methods Home interviews assessed depression (lifetime-ever), fatigue and environmental exposures in 4,024 randomly selected twins from a population-based register in the Colombo district of Sri Lanka. Results Early school leaving and standard of living showed environmentally-mediated effects on depression, in men. In women, life events were associated with depression partly through genetic pathways (however, the temporal order is consistent with life events being an outcome of depression, as well as the other way around). For fatigue, there were environmentally mediated effects (through early school leaving and life events) and strong suggestions of family-environmental influences. Conclusions Compared to previous studies from higher-income countries, novel environmentally-mediated risk factors for depression and fatigue were identified in Sri Lanka. But as seen elsewhere, the association between life events and depression was partially genetically mediated in women. These results have implications for understanding environmental mechanisms around the world

    An economic evaluation of Alexander Technique lessons or acupuncture sessions for patients with chronic neck pain : A randomized trial (ATLAS)

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    OBJECTIVES: To assess the cost-effectiveness of acupuncture and usual care, and Alexander Technique lessons and usual care, compared with usual GP care alone for chronic neck pain patients. METHODS: An economic evaluation was undertaken alongside the ATLAS trial, taking both NHS and wider societal viewpoints. Participants were offered up to twelve acupuncture sessions or twenty Alexander lessons (equivalent overall contact time). Costs were in pounds sterling. Effectiveness was measured using the generic EQ-5D to calculate quality adjusted life years (QALYs), as well as using a specific neck pain measure-the Northwick Park Neck Pain Questionnaire (NPQ). RESULTS: In the base case analysis, incremental QALY gains were 0.032 and 0.025 in the acupuncture and Alexander groups, respectively, in comparison to usual GP care, indicating moderate health benefits for both interventions. Incremental costs were £451 for acupuncture and £667 for Alexander, mainly driven by intervention costs. Acupuncture was likely to be cost-effective (ICER = £18,767/QALY bootstrapped 95% CI £4,426 to £74,562) and was robust to most sensitivity analyses. Alexander lessons were not cost-effective at the lower NICE threshold of £20,000/QALY (£25,101/QALY bootstrapped 95% CI -£150,208 to £248,697) but may be at £30,000/QALY, however, there was considerable statistical uncertainty in all tested scenarios. CONCLUSIONS: In comparison with usual care, acupuncture is likely to be cost-effective for chronic neck pain, whereas, largely due to higher intervention costs, Alexander lessons are unlikely to be cost-effective. However, there were high levels of missing data and further research is needed to assess the long-term cost-effectiveness of these interventions

    Increasing frailty is associated with higher prevalence and reduced recognition of delirium in older hospitalised inpatients: results of a multi-centre study

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    Purpose: Delirium is a neuropsychiatric disorder delineated by an acute change in cognition, attention, and consciousness. It is common, particularly in older adults, but poorly recognised. Frailty is the accumulation of deficits conferring an increased risk of adverse outcomes. We set out to determine how severity of frailty, as measured using the CFS, affected delirium rates, and recognition in hospitalised older people in the United Kingdom. Methods: Adults over 65 years were included in an observational multi-centre audit across UK hospitals, two prospective rounds, and one retrospective note review. Clinical Frailty Scale (CFS), delirium status, and 30-day outcomes were recorded. Results: The overall prevalence of delirium was 16.3% (483). Patients with delirium were more frail than patients without delirium (median CFS 6 vs 4). The risk of delirium was greater with increasing frailty [OR 2.9 (1.8–4.6) in CFS 4 vs 1–3; OR 12.4 (6.2–24.5) in CFS 8 vs 1–3]. Higher CFS was associated with reduced recognition of delirium (OR of 0.7 (0.3–1.9) in CFS 4 compared to 0.2 (0.1–0.7) in CFS 8). These risks were both independent of age and dementia. Conclusion: We have demonstrated an incremental increase in risk of delirium with increasing frailty. This has important clinical implications, suggesting that frailty may provide a more nuanced measure of vulnerability to delirium and poor outcomes. However, the most frail patients are least likely to have their delirium diagnosed and there is a significant lack of research into the underlying pathophysiology of both of these common geriatric syndromes

    Acupuncture and counselling for depression in primary care : a randomised controlled trial

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    Background: Depression is a significant cause of morbidity. Many patients have communicated an interest in nonpharmacological therapies to their general practitioners. Systematic reviews of acupuncture and counselling for depression in primary care have identified limited evidence. The aim of this study was to evaluate acupuncture versus usual care and counselling versus usual care for patients who continue to experience depression in primary care. Methods and Findings: In a randomised controlled trial, 755 patients with depression (Beck Depression Inventory BDI-II score $20) were recruited from 27 primary care practices in the North of England. Patients were randomised to one of three arms using a ratio of 2:2:1 to acupuncture (302), counselling (302), and usual care alone (151). The primary outcome was the difference in mean Patient Health Questionnaire (PHQ-9) scores at 3 months with secondary analyses over 12 months follow-up. Analysis was by intention-to-treat. PHQ-9 data were available for 614 patients at 3 months and 572 patients at 12 months. Patients attended a mean of ten sessions for acupuncture and nine sessions for counselling. Compared to usual care, there was a statistically significant reduction in mean PHQ-9 depression scores at 3 months for acupuncture (22.46, 95% CI 23.72 to 21.21) and counselling (21.73, 95% CI 23.00 to 20.45), and over 12 months for acupuncture (21.55, 95% CI 22.41 to 20.70) and counselling (21.50, 95% CI 22.43 to 20.58). Differences between acupuncture and counselling were not significant. In terms of limitations, the trial was not designed to separate out specific from non-specific effects. No serious treatment-related adverse events were reported. Conclusions: In this randomised controlled trial of acupuncture and counselling for patients presenting with depression, after having consulted their general practitioner in primary care, both interventions were associated with significantly reduced depression at 3 months when compared to usual care alone

    Development and psychometric properties of a five-language multiperspective instrument to assess clinical decision making style in the treatment of people with severe mental illness (CDMS)

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    BACKGROUND: The aim of this study was to develop and evaluate psychometric properties of the Clinical Decision Making Style (CDMS) scale which measures general preferences for decision making as well as preferences regarding the provision of information to the patient from the perspectives of people with severe mental illness and staff. METHODS: A participatory approach was chosen for instrument development which followed 10 sequential steps proposed in a current guideline of good practice for the translation and cultural adaptation of measures. Following item analysis, reliability, validity, and long-term stability of the CDMS were examined using Spearman correlations in a sample of 588 people with severe mental illness and 213 mental health professionals in 6 European countries (Germany, UK, Italy, Denmark, Hungary, and Switzerland). RESULTS: In both patient and staff versions, the two CDMS subscales "Participation in Decision Making" and "Information" reliably measure distinct characteristics of decision making. Validity could be demonstrated to some extent, but needs further investigation. CONCLUSIONS: Together with two other five-language patient- and staff-rated measures developed in the CEDAR study (ISRCTN75841675) - "Clinical Decision Making in Routine Care" and "Clinical Decision Making Involvement and Satisfaction" - the CDMS allows empirical investigation of the complex relation between clinical decision making and outcome in the treatment of people with severe mental illness across Europe
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