Publications by authors named "Jake Powrie"

Type 1 diabetes is characterized by a loss of tolerance to pancreatic β-cell autoantigens and defects in regulatory T-cell (Treg) function. In preclinical models, immunotherapy with MHC-selective, autoantigenic peptides restores immune tolerance, prevents diabetes, and shows greater potency when multiple peptides are used. To translate this strategy into the clinical setting, we administered a mixture of six HLA-DRB1*0401-selective, β-cell peptides intradermally to patients with recent-onset type 1 diabetes possessing this genotype in a randomized placebo-controlled study at monthly doses of 10, 100, and 500 μg for 24 weeks.

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Article Synopsis
  • Immunotherapy that uses short immunogenic peptides from autoantigens shows promise in restoring immune tolerance in type 1 diabetes, with a study focused on proinsulin peptides in patients.
  • The treatment was well tolerated and did not lead to increased hypersensitivity, while placebo patients experienced a decline in insulin reserve and an increase in insulin usage over time.
  • Results indicated that the treated patients maintained C-peptide levels and exhibited signs of immune modulation, suggesting that proinsulin peptide therapy could safely preserve β cell function in type 1 diabetes.
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Autoreactive CD8 T cells play a central role in the destruction of pancreatic islet β-cells that leads to type 1 diabetes, yet the key features of this immune-mediated process remain poorly defined. In this study, we combined high-definition polychromatic flow cytometry with ultrasensitive peptide-human leukocyte antigen class I tetramer staining to quantify and characterize β-cell-specific CD8 T cell populations in patients with recent-onset type 1 diabetes and healthy control subjects. Remarkably, we found that β-cell-specific CD8 T cell frequencies in peripheral blood were similar between subject groups.

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Studies in type 1 diabetes indicate potential disease heterogeneity, notably in the rate of β-cell loss, responsiveness to immunotherapies, and, in limited studies, islet pathology. We sought evidence for different immunological phenotypes using two approaches. First, we defined blood autoimmune response phenotypes by combinatorial, multiparameter analysis of autoantibodies and autoreactive T-cell responses in 33 children/adolescents with newly diagnosed diabetes.

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Type 1 diabetes results from T cell-mediated β-cell destruction. The HLA-A*24 class I gene confers significant risk of disease and early onset. We tested the hypothesis that HLA-A24 molecules on islet cells present preproinsulin (PPI) peptide epitopes to CD8 cytotoxic T cells (CTLs).

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Objective: CD4 T-cells secreting interleukin (IL)-17 are implicated in several human autoimmune diseases, but their role in type 1 diabetes has not been defined. To address the relevance of such cells, we examined IL-17 secretion in response to β-cell autoantigens, IL-17A gene expression in islets, and the potential functional consequences of IL-17 release for β-cells.

Research Design And Methods: Peripheral blood CD4 T-cell responses to β-cell autoantigens (proinsulin, insulinoma-associated protein, and GAD65 peptides) were measured by IL-17 enzyme-linked immunospot assay in patients with new-onset type 1 diabetes (n = 50).

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Introduction: Chronic low-dose cabergoline treatment for microprolactinoma may cause cardiac valve pathology, but the evidence is contradictory. We investigated whether the expectation of the echocardiographer could influence the report.

Methods: Transthoracic echocardiograms from 40 patients aged 49·3 ± 9·6 (mean ± SD) years (Men:Women 7:33) on long-term cabergoline and bromocriptine therapy (duration 9·94 ± 4·5 years) were randomly assigned to two groups of echocardiographers so that each echocardiogram was reported twice.

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Objectives: Oral oestrogen preparations increase total cortisol concentration by increasing circulating cortisol-binding globulin (CBG) levels. Transdermal oestrogen treatments are being used increasingly in clinical practice. These topical preparations may have less of an effect on CBG and hence on total serum cortisol levels by reducing hepatic oestrogen exposure.

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Diabetes mellitus is a major health problem across the world. Diabetic retinopathy (DR) and nephropathy are two of the major complications of diabetes. DR is the leading cause of blindness and diabetic nephropathy is the leading cause of end-stage renal failure.

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Diabetic retinopathy is the commonest complication of diabetes and is the biggest single cause of registered blindness in the UK. No biochemical tests exist to determine the precise state and rate of change of the eyes in the diabetic patient. In the present study, using real-time quantitative reverse transcriptase polymerase chain reaction (RT-PCR), we measured mRNA encoding the retina-specific pigment protein rhodopsin (RHO) in the peripheral blood of healthy individuals (n = 20) and diabetic patients (n = 46) with and without retinopathy.

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