Type 1 diabetes (T1D) is an autoimmune disorder with unambiguous involvement of both innate and adaptive immune mechanisms in the destruction of pancreatic beta cells. Recent evidence demonstrated ...that neutrophils infiltrate the pancreas prior to disease onset and therein extrude neutrophil extracellular traps (NETs), web-like structures of DNA and nuclear proteins with a strong pro-inflammatory biologic activity. Our previous work showed that T1D NETs activate dendritic cells, which consequently induce IFNγ-producing Th1 lymphocytes. The aim of this study was to assess direct
biomarkers of NETosis in the serum of recent onset and long-term pediatric T1D patients, their first-degree relatives and healthy controls. To this end we evaluated serum levels of myeloperoxidase (MPO), neutrophil elastase (NE), proteinase 3 (PR3), protein arginine deiminase 4 (PAD4), LL37 and cell-free DNA-histone complexes in sex- and age-matched cohorts of T1D first-degree relatives, recent-onset T1D patients, and in patients 12 months after clinical manifestation of the disease. Our data shows that disease onset is accompanied by peripheral neutrophilia and significant elevation of MPO, NE, PR3, PAD4 and cell-free DNA-histone complexes. Most biomarkers subsequently decrease but do not always normalize in long-term patients. First-degree relatives displayed an intermediate phenotype, except for remarkably high levels of LL37. Together, this report provides evidence for the presence of ongoing NETosis in pediatric patients with T1D at time of clinical manifestation of the disease, which partly subsides in subsequent years.
► Thirty percent of patients with T1D exhibit increased levels of m-α-defensin mRNAs in their capillary blood. ► Increased m-α-defensin levels were observed in capillary but not in venous blood ...samples. ► CD15dull/CD14weak eosinophil population was identified as the cellular source of m-α-defensins. ► Eosinophils from all T1D patients tested displayed augmented m-α-defensin expression. ► Eosinophils could contribute to the magnitude of inflammation and β-cell destruction.
Type 1 diabetes (T1D) is an autoimmune disease caused by T-cell mediated destruction of pancreatic beta cells. Recently, small cationic α-defensin molecules have been implicated in the pathogenesis of certain inflammatory and autoimmune diseases. The purpose of this study was to assess the α-defensin expression in patients with T1D and elucidate the cellular source of their production. Our results show that 30% of patients exhibit increased levels of α-defensin mRNAs in their capillary blood. Quantitative RT-PCR performed on FACS-sorted granulocytes identified CD15dull/CD14weak population as the cellular source of α-defensins. Surprisingly, this granulocyte subpopulation displayed augmentation of α-defensin expression in all T1D patients tested. The determination of cell surface markers, expression of cell-specific genes and confocal microscopy identified CD15dull/CD14weak cells as eosinophils. The presence of transcriptionally active eosinophils in diabetic patients suggests that eosinophils could be a part of an intricate innate immune cellular network involved in the development of diabetes.
Type 1 Diabetes (T1D) is considered to be a T-helper- (Th-) 1 autoimmune disease; however, T1D pathogenesis likely involves many factors, and sufficient tools for autoreactive T cell detection for ...the study of this disease are currently lacking. In this study, using gene expression microarrays, we analysed the effect of diabetes-associated autoantigens on peripheral blood mononuclear cells (PBMCs) with the purpose of identifying (pre)diabetes-associated cell processes. Twelve patients with recent onset T1D, 18 first-degree relatives of the TD1 patients (DRL; 9/18 autoantibody positive), and 13 healthy controls (DV) were tested. PBMCs from these individuals were stimulated with a cocktail of diabetes-associated autoantigens (proinsulin, IA-2, and GAD65-derived peptides). After 72 hours, gene expression was evaluated by high-density gene microarray. The greatest number of functional differences was observed between relatives and controls (69 pathways), from which 15% of the pathways belonged to “immune response-related” processes. In the T1D versus controls comparison, more pathways (24%) were classified as “immune response-related.” Important pathways that were identified using data from the T1D versus controls comparison were pathways involving antigen presentation by MHCII, the activation of Th17 and Th22 responses, and cytoskeleton rearrangement-related processes. Genes involved in Th17 and TGF-beta cascades may represent novel, promising (pre)diabetes biomarkers.
Abstract Objective Dendritic cells (DCs) play an important role in pathogenesis of autoimmunity, including type 1 diabetes (T1D). In this study, we investigated DC subpopulations and their responses ...to TLR stimulation in T1D patients and their relatives. Methods We analyzed the frequency of myeloid (mDCs) and plasmacytoid DCs (pDCs) in 97 T1D patients (69 onset, 28 long-term), 67 first-degree relatives, and 64 controls. We additionally tested the IFN-alpha production by pDCs upon stimulation with TLR 7, 8 and 9 agonists. Results A lower number of mDCs and pDCs were found in T1D patients and their relatives. Of all the tested TLR ligands, only stimulation with CpG 2216 induced IFN-alpha production that was the highest in T1D relatives, except of autoantibody-negative relatives bearing the protective haplotypes. Conclusion Our data demonstrate disturbances in DC number and function expressed most significantly in T1D relatives and point to a potential role of TLR9-induced IFN-alpha production in T1D development.
•T1D patient’s autoantibody profile and cytokine production was examined.•Increased IL17 production was found in patients with high IA2 autoantibodies.•The titre of IA2 autoantibodies correlates with ...the proportion of Tc and Th cells.•Patient’s autoantibody profile reflects immune cellular responses.
Type 1 diabetes (T1D) is an autoimmune disorder characterised by the immune-mediated destruction of insulin-producing pancreatic beta cells. The inflammatory process appears to be primarily mediated by pro-inflammatory Th1 lymphocytes, while the role Th17 cells in T1D is currently being investigated. T1D is characterised by the presence of autoantigen-specific autoantibodies.
This study was conducted using patients with confirmed T1D and healthy control subjects. We examined the effect of the patient’s autoantibody profile on peripheral blood mononuclear cell (PBMC) cytokine production following stimulation with the major diabetogenic autoantigens GAD65 and IA2. IFN-gamma and IL17 production was detected by ELISPOT and the ratio of basic cellular populations in PBMCs was measured by flow cytometry.
We demonstrated a significant interaction between the patient’s autoantibody profile and mode of stimulation. This suggests that autoantigen stimulation has a different effect on different groups of patients depending on their autoantibody profile. An increased production of IL17 was found in patients with high IA2 autoantibodies compared to patients with low levels of autoantibodies and healthy controls regardless of the mode of stimulation. The titre of IA2 autoantibodies positively correlates with the proportion of Tc lymphocytes and negatively correlates with the proportion of Th lymphocytes.
Our results show that a patient’s autoantibody profile reflects the type of cellular immune responses. It seems that the high titre of IA2 autoantibodies is related to increased production of IL17 and an increased proportion of Tc lymphocytes. This finding may be useful in designing immunointervention studies to prevent T1D.
5 Abstract Type 1 diabetes (T1D) is an organ specific autoimmune disorder characterised by the immune-mediated destruction of insulin-producing pancreatic beta cells. Beta-cell destruction is ...mediated primarily by cellular components of the immune system, especially auto-reactive T cells. Nowadays, a goal of many studies is built up the best system for identification of individuals in prediabetes stage and to treat them to preserve sufficient amount of insulin producing beta cells. We identified several candidate pathways and proteins which could be important in pathology of T1D, like an antiviral responses and differentiation of Th17 pathways. We observed differences in dendritic cells count and in their cytokines production. Our data support the notion that the establishment of proinflammatory environment in genetically predisposed individuals along with the involvement of non-specific immune mechanisms is critical for the initiation of autoimmune, destructive insulitis. Nonetheless, patient's autoantibody profile reflects the type of cellular immune response and should be take in a count as well. This finding may be useful in design of immunointervention studies to prevent T1D. Considering the heterogeneity of the clinical course of this disease and perhaps different mechanisms of molecular pathology,...
Type 1 diabetes (T1D) is an autoimmune disease characterized by the lack of insulin due to an autoimmune destruction of pancreatic beta cells. Here, we report a unique case of a family with naturally ...conceived quadruplets in which T1D was diagnosed in two quadruplets simultaneously. At the same time, the third quadruplet was diagnosed with the pre-diabetic stage. Remarkably, all four quadruplets were positive for anti-islet cell antibodies, GAD65 and IA-A2. Monozygotic status of the quadruplets was confirmed by testing 14 different short tandem repeat polymorphisms. Serological examination confirmed that all quadruplets and their father suffered from a recent enteroviral infection of EV68-71 serotype. To assess the nature of the molecular pathological processes contributing to the development of diabetes, immunocompetent cells isolated from all family members were characterized by gene expression arrays, immune-cell enumerations and cytokine-production assays. The microarray data provided evidence that viral infection, and IL-27 and IL-9 cytokine signalling contributed to the onset of T1D in two of the quadruplets. The propensity of stimulated immunocompetent cells from non-diabetic members of the family to secrete high level of IFN-α further corroborates this conclusion. The number of T regulatory cells as well as plasmacytoid and/or myeloid dendritic cells was found diminished in all family members. Thus, this unique family is a prime example for the support of the so-called 'fertile-field' hypothesis proposing that genetic predisposition to anti-islet autoimmunity is 'fertilized' and precipitated by a viral infection leading to a fully blown T1D.
Provider: Czech digital library/Česká digitální knihovna - Institution: National Medical Library/Národní lékařská knihovna - Data provided by Europeana Collections- Diabetes 1. typu (DM1) vzniká jako ...následek autoimunitní destrukce beta buněk pankreatu. Vliv diabetu na celkový výsledek těhotenství je poměrně dobře prostudován. Mnohem méně se toho však ví o vlivu diabetu matky na vyvíjející se imunitní systém plodu. Riziko rozvoje DM1 u dětí diabetických matek (pokud onemocněly před těhotenstvím) je nižší než např. u dětí diabetických otců. Tato diskrepance podporuje teorii, že by mohlo docházet k určitému navození imunotolerance u dětí DM1 matek. Z tohoto důvodu jsme si pro náš výzkum vybrali T regulační buňky (Tregs), které hrají důležitou roli v imunoregulaci a patogenezi mnoha autoimunitních onemocnění. Studie Tregs pupečníkové krve DM1 matek jsou navíc ojedinělé. Pomocí průtokové cytometrie jsme analyzovali zastoupení Tregs (definovaných jako CD45+ CD3+ CD4+ CD25+ CD127(low/-)) ve vzorcích pupečníkové krve od 17 matek s DM1, 17 s gestačním diabetem a 42 zdravých kontrol. Signifikantní rozdíl jsme nalezli jen v zastoupení Tregs z Th lymfocytů, kde v pupečníkové krvi zdravých matek činil tento poměr 9,25 % a u matek s DM1 6,73 % (p=0,043). Ostatní rozdíly nedosáhly signifikance. Pokud tedy dochází k navození specifické imunotolerance, je tato patrně podmíněna jinak než změnou počtu Tregs. Pokračujeme proto ve funkční analýze Tregs s cílem nalézt vysvětlení pro nižší výskyt diabetu u dětí DM1 matek ve srovnání s ostatními prvostupňovými příbuznými DM1 pacientů. Pochopení tohoto jevu by mohlo přispět např. i k vytvoření imunointervenční terapie DM1.- Type 1 diabetes (T1D) develops due to autoimmune pancreatic beta cells destruction. The effect of diabetes on pregnancy outcome is well documented. However, much less is known about the effect of maternal diabetes on the developing foetal immune system. The risk of T1D development in a child of T1D mother who was diagnosed prior pregnancy is lower than e.g. in a child of T1D father. This discrepancy supports the theory that there is some immunoregulatory influence on her baby. For this reason we decided to study T regulatory cells (Tregs) which are important in immunoregulation and for autoimmune diseases pathogenesis. Moreover Tregs cord blood (CB) studies of T1D mothers are limited. Tregs defined as CD45+ CD3+ CD4+ CD25+ CD127(low/-) in CB samples were investigated in our study by flow cytometry and 17 T1D mothers, 17 gestation diabetes mothers and 42 healthy controls were enrolled. We found just that CB from babies of T1D mothers contained 6,73 % Tregs/total Th-lymfocytes in comparison to 9,25 % in controls (p = 0,043). Other differences were not significant. If an establishment of specific immunological tolerance in foetus of T1D mother really exists, it seems to be rather due to other factors than just to changes in Tregs count (which was moreover found to be decreased). We are currently focused on explanation why children of T1D mothers suffer from diabetes less frequently than other first degree relatives by using functional analysis of Tregs. Insights in to this phenomenon would be useful e.g. for construction of T1D immunointervention therapy.- Tereza Ulmannová, Jindra Norková , Jana Včeláková, Dagmar Bartášková, Ivana Špálová, Kateřina Štechová: T regulační buňky v pupečníkové krvi dětí diabetických matek- Literatura 20- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Pregnanolone isomers (PIs) and their polar conjugates (PICs) modulate ionotropic receptors such as γ-aminobutyric acid or pregnane X receptors. Besides, brain synthesis, PI penetrates the blood–brain ...barrier. We evaluated the physiological importance of PI respecting the status of sex, menstrual cycle, and pregnancy. Accordingly, circulating levels of allopregnanolone (P3α 5α ), isopregnanolone (P3β 5α ), pregnanolone (P3α 5β ), epipregnanolone (P3β 5β ), their polar conjugates, and related steroids were measured in 15 men (M), 15 women in the follicular phase (F), 16 women in the luteal phase (L), and 30 women in the 36th week of gestation (P) using GC–MS. The steroid levels were similar in M and F, increased about thrice in L and escalated in P (38–410 times compared with F). The PICs were prevalent over the PIs (16–150 times). Higher ratios of 5α-PIC to 5α-PI found in P indicate the more intensive conjugation of 5α-PI during pregnancy. This mechanism probably provides for the elimination of neuroinhibitory P3α 5α in the maternal compartment. Additionally, our result points to a limited sulfation capacity for neuroinhibitory P3α 5β in P. In contrast to the situation in M, F, and L where the P3α 5β C is the most abundant PIC, and P3α 5β is present in minor quantities compared with the P3α 5α , P3α 5β may acquire physiological importance during pregnancy, contributing to the sustaining thereof. On the other hand, the declining formation of P3α 5β may participate in the initiation of parturition, given the relative abundance of the steroid, its potency to suppress the activity of oxytocin-producing cells and its effectiveness in uterine relaxation.
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