Blood and islet phenotypes indicate immunological heterogeneity in type 1 diabetes

This is an author-created, uncopyedited electronic version of an article accepted for publication in Diabetes. The American Diabetes Association (ADA), publisher of Diabetes, is not responsible for any errors or omissions in this version of the manuscript or any version derived from it by third parties. The definitive publisher-authenticated version is available in Diabetes in print and online at http://diabetes.diabetesjournals.orgThe erratum to this article is available in ORE at http://hdl.handle.net/10871/40335Studies 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. Multidimensional cluster analysis showed two equal-sized patient agglomerations characterized by proinflammatory (interferon-γ-positive, multiautoantibody-positive) and partially regulated (interleukin-10-positive, pauci-autoantibody-positive) responses. Multiautoantibody-positive nondiabetic siblings at high risk of disease progression showed similar clustering. Additionally, pancreas samples obtained post mortem from a separate cohort of 21 children/adolescents with recently diagnosed type 1 diabetes were examined immunohistologically. This revealed two distinct types of insulitic lesions distinguishable by the degree of cellular infiltrate and presence of B cells that we termed "hyper-immune CD20Hi" and "pauci-immune CD20Lo." Of note, subjects had only one infiltration phenotype and were partitioned by this into two equal-sized groups that differed significantly by age at diagnosis, with hyper-immune CD20Hi subjects being 5 years younger. These data indicate potentially related islet and blood autoimmune response phenotypes that coincide with and precede disease. We conclude that different immunopathological processes (endotypes) may underlie type 1 diabetes, carrying important implications for treatment and prevention strategies.JDRFNational Institute for Health Research (NIHR) Biomedical Research Centre based at Guy’s and St Thomas’ NHS Foundation Trust and King’s College LondonEuropean Union (EU FP7) award - Persistent Virus Infection in Diabetes Network Study Group (PEVNET)EU FP7 Large-Scale Focused Collaborative Research Project on Natural Immunomodulators as Novel Immunotherapies for Type 1 Diabetes (NAIMIT)EU FP7 Large-Scale Focused Collaborative Research Project on β-cell preservation through antigen-specific immunotherapy in Type 1 Diabetes: Enhanced Epidermal Antigen Delivery Systems (EE-ASI)National Institutes of Health (NIH)National Institute of Diabetes and Digestive and Kidney DiseasesNational Institute of Allergy and Infectious DiseasesEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Center for Research ResourcesGeneral Clinical Research CenterAmerican Diabetes Association (ADA

Metabolic and immune effects of immunotherapy with proinsulin peptide in human new-onset type 1 diabetes*

Immunotherapy using short immunogenic peptides of disease-related autoantigens restores immune tolerance in preclinical disease models. We studied safety and mechanistic effects of injecting human leukocyte antigen–DR4(DRB1*0401)–restricted immunodominant proinsulin peptide intradermally every 2 or 4 weeks for 6 months in newly diagnosed type 1 diabetes patients. Treatment was well tolerated with no systemic or local hypersensitivity. Placebo subjects showed a significant decline in stimulated C-peptide (measuring insulin reserve) at 3, 6, 9, and 12 months versus baseline, whereas no significant change was seen in the 4-weekly peptide group at these time points or the 2-weekly group at 3, 6, and 9 months. The placebo group’s daily insulin use increased by 50% over 12 months but remained unchanged in the intervention groups. C-peptide retention in treated subjects was associated with proinsulin-stimulated interleukin-10 production, increased FoxP3 expression by regulatory T cells, low baseline levels of activated β cell–specific CD8 T cells, and favorable β cell stress markers (proinsulin/C-peptide ratio). Thus, proinsulin peptide immunotherapy is safe, does not accelerate decline in β cell function, and is associated with antigen-specific and nonspecific immune modulation

Peripheral and islet interleukin-17 pathway activation characterizes human autoimmune diabetes and promotes cytokine-mediated β-cell death

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). mRNA expression of IL-17A and IFNG pathway genes was studied by qRT-PCR using islets obtained from subjects who died 5 days and 10 years after diagnosis of disease, respectively, and from matched control subjects. IL-17 effects on the function of human islets, rat β-cells, and the rat insulinoma cell line INS-1E were examined. RESULTS A total of 27 patients (54%) showed IL-17 reactivity to one or more β-cell peptides versus 3 of 30 (10%) control subjects (P = 0.0001). In a single case examined close to diagnosis, islet expression of IL17A, RORC, and IL22 was detected. It is noteworthy that we show that IL-17 mediates significant and reproducible enhancement of IL-1β/interferon (IFN)-γ–induced and tumor necrosis factor (TNF)-α/IFN-γ–induced apoptosis in human islets, rat β-cells, and INS-1E cells, in association with significant upregulation of β-cell IL17RA expression via activation of the transcription factors STAT1 and nuclear factor (NF)-κB. CONCLUSIONS Circulating IL-17+ β-cell–specific autoreactive CD4 T-cells are a feature of type 1 diabetes diagnosis. We disclose a novel pathway to β-cell death involving IL-17 and STAT1 and NF-κB, rendering this cytokine a novel disease biomarker and potential therapeutic targe

Inherited mutations in the SDH complex increase metastatic malignant potential of paragnglioma and phaeochromocytoma tumours

<p>Phaeochromocytomas (PCC) and paraganglioma (PGL) are neural crest tumours arising from the chromaffin producing cells of the adrenal medulla or sympathetic/parasympathetic system respectively. Recently, in part due to advances in high throughput sequencing, our understanding of the genetic predisposition to these tumours has greatly increased. To date, 13 genes have been implicated in the pathogenesis of these conditions (ten available for testing at our centre). Recent studies indicate that ~30–40% of patients with PCC/PGL may harbour a genetic predisposition to the condition. We aimed to determine the frequency that metastatic PCC/PGL was associated with mutations in known susceptibility genes.</p> <p>The genetic profile of all individuals diagnosed with metastatic PCC and PGL in our centre was ascertained and compared to individuals with PCC/PGL without evidence of metastasis. Over the past 5 years 82 individuals with a diagnosis of PCC or PGL fulfilled the criteria for genetic testing. This included 16 individuals with metastatic disease. Among the patients with confirmed metastatic disease 13/16 (81%) had a genetic mutation identified in SDHB, SDHA, or SDHD predisposing to PCC and PGL. However, among those patients with no metastatic disease identified to date, only 42% (29/69) had a genetic mutation identified (P=0.001). Among the subjects with metastatic PCC, 11/13 had mutations (85%) in SDHB.</p> <p>Our results imply that the identification of a mutation in the known PCC/PGL susceptibility genes confers an increased metastatic potential and also subjects with metastatic disease are most likely to harbour mutations in SDHB. Subjects with metastatic PGL/PCC are highly likely to have a genetic predisposition. In addition, identification of those individuals with PGL/PCC with a genetic mutation should be considered at high-risk for harbouring tumours with metastatic malignant potential.</p