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2.
Cell Stress Chaperones ; 29(2): 312-325, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38490439

RESUMO

Type 1 diabetes (T1D) is characterized by lymphocyte infiltration into the pancreatic islets of Langerhans, leading to the destruction of insulin-producing beta cells and uncontrolled hyperglycemia. In the nonobese diabetic (NOD) murine model of T1D, the onset of this infiltration starts several weeks before glucose dysregulation and overt diabetes. Recruitment of immune cells to the islets is mediated by several chemotactic cytokines, including CXCL10, while other cytokines, including SDF-1α, can confer protective effects. Global gene expression studies of the pancreas from prediabetic NOD mice and single-cell sequence analysis of human islets from prediabetic, autoantibody-positive patients showed an increased expression of metallothionein (MT), a small molecular weight, cysteine-rich metal-binding stress response protein. We have shown that beta cells can release MT into the extracellular environment, which can subsequently enhance the chemotactic response of Th1 cells to CXCL10 and interfere with the chemotactic response of Th2 cells to SDF-1α. These effects can be blocked in vitro with a monoclonal anti-MT antibody, clone UC1MT. When administered to NOD mice before the onset of diabetes, UC1MT significantly reduces the development of T1D. Manipulation of extracellular MT may be an important approach to preserving beta cell function and preventing the development of T1D.


Assuntos
Diabetes Mellitus Tipo 1 , Estado Pré-Diabético , Humanos , Camundongos , Animais , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/prevenção & controle , Camundongos Endogâmicos NOD , Metalotioneína/genética , Metalotioneína/metabolismo , Quimiocina CXCL12
3.
Diabetes Care ; 47(5): 826-834, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38498185

RESUMO

OBJECTIVE: To explore associations of HLA class II genes (HLAII) with the progression of islet autoimmunity from asymptomatic to symptomatic type 1 diabetes (T1D). RESEARCH DESIGN AND METHODS: Next-generation targeted sequencing was used to genotype eight HLAII genes (DQA1, DQB1, DRB1, DRB3, DRB4, DRB5, DPA1, DPB1) in 1,216 participants from the Diabetes Prevention Trial-1 and Randomized Diabetes Prevention Trial with Oral Insulin sponsored by TrialNet. By the linkage disequilibrium, DQA1 and DQB1 are haplotyped to form DQ haplotypes; DP and DR haplotypes are similarly constructed. Together with available clinical covariables, we applied the Cox regression model to assess HLAII immunogenic associations with the disease progression. RESULTS: First, the current investigation updated the previously reported genetic associations of DQA1*03:01-DQB1*03:02 (hazard ratio [HR] = 1.25, P = 3.50*10-3) and DQA1*03:03-DQB1*03:01 (HR = 0.56, P = 1.16*10-3), and also uncovered a risk association with DQA1*05:01-DQB1*02:01 (HR = 1.19, P = 0.041). Second, after adjusting for DQ, DPA1*02:01-DPB1*11:01 and DPA1*01:03-DPB1*03:01 were found to have opposite associations with progression (HR = 1.98 and 0.70, P = 0.021 and 6.16*10-3, respectively). Third, DRB1*03:01-DRB3*01:01 and DRB1*03:01-DRB3*02:02, sharing the DRB1*03:01, had opposite associations (HR = 0.73 and 1.44, P = 0.04 and 0.019, respectively), indicating a role of DRB3. Meanwhile, DRB1*12:01-DRB3*02:02 and DRB1*01:03 alone were found to associate with progression (HR = 2.6 and 2.32, P = 0.018 and 0.039, respectively). Fourth, through enumerating all heterodimers, it was found that both DQ and DP could exhibit associations with disease progression. CONCLUSIONS: These results suggest that HLAII polymorphisms influence progression from islet autoimmunity to T1D among at-risk subjects with islet autoantibodies.


Assuntos
Diabetes Mellitus Tipo 1 , Humanos , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/prevenção & controle , Soroconversão , Genótipo , Haplótipos , Progressão da Doença , Cadeias HLA-DRB1/genética , Cadeias beta de HLA-DQ/genética , Alelos , Frequência do Gene
4.
Proc Natl Acad Sci U S A ; 121(6): e2315419121, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38285952

RESUMO

Persistent antigen exposure results in the differentiation of functionally impaired, also termed exhausted, T cells which are maintained by a distinct population of precursors of exhausted T (TPEX) cells. T cell exhaustion is well studied in the context of chronic viral infections and cancer, but it is unclear whether and how antigen-driven T cell exhaustion controls progression of autoimmune diabetes and whether this process can be harnessed to prevent diabetes. Using nonobese diabetic (NOD) mice, we show that some CD8+ T cells specific for the islet antigen, islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) displayed terminal exhaustion characteristics within pancreatic islets but were maintained in the TPEX cell state in peripheral lymphoid organs (PLO). More IGRP-specific T cells resided in the PLO than in islets. To examine the impact of extraislet antigen exposure on T cell exhaustion in diabetes, we generated transgenic NOD mice with inducible IGRP expression in peripheral antigen-presenting cells. Antigen exposure in the extraislet environment induced severely exhausted IGRP-specific T cells with reduced ability to produce interferon (IFN)γ, which protected these mice from diabetes. Our data demonstrate that T cell exhaustion induced by delivery of antigen can be harnessed to prevent autoimmune diabetes.


Assuntos
Diabetes Mellitus Tipo 1 , Ilhotas Pancreáticas , Camundongos , Animais , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/prevenção & controle , Proteínas/metabolismo , Exaustão das Células T , Glucose-6-Fosfatase/genética , Glucose-6-Fosfatase/metabolismo , Camundongos Transgênicos , Camundongos Endogâmicos NOD , Ilhotas Pancreáticas/metabolismo , Linfócitos T CD8-Positivos
5.
Pol Arch Intern Med ; 134(1)2024 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-38164523

RESUMO

INTRODUCTION: Clinical remission in type 1 diabetes (T1D) results from metabolic compensation after insulin implementation and is caused by various factors. OBJECTIVES: Our aim was to investigate an association between air pollution defined based on ozone concentration in the month of T1D diagnosis and the early course of the disease, that is, glucose metabolism and the occurrence of remission. PATIENTS AND METHODS: This prospective, observational analysis included 96 adult patients with newly diagnosed T1D. The study group was divided according to the occurrence of remission at 12 months after the diagnosis. The levels of ambient ozone measured within the month of T1D diagnosis were calculated using the official data of Poland's Chief Inspectorate of Environmental Protection. Remission was defined according to the following formula: actual glycated hemoglobin (HbA1c)(%) level + [4 × insulin dose (units/kg per 24 h)] - value defining partial remission ≤9. RESULTS: The remission rate after 12 months was higher in the group where ozone concentration was below or equal to the median for the study population (P <0.001). Moreover, the patients in the group where ozone levels were above the median, presented lower C­peptide levels (P = 0.01), higher HbA1c concentration (P = 0.005), and higher daily insulin requirements (P = 0.02) after 12 months from the diagnosis. Also, in the group of participants achieving remission, the ambient ozone level was lower (P <0.001). In a multivariable logistic regression analysis, the increased ozone concentration in the month of diagnosis was the variable that influenced the lack of remission after 12 months, independently of sex and smoking (P <0.001). CONCLUSIONS: Increased ozone level may exacerbate metabolic outcomes and reduce remission in T1D.


Assuntos
Diabetes Mellitus Tipo 1 , Ozônio , Adulto , Humanos , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/prevenção & controle , Hemoglobinas Glicadas , Insulina/uso terapêutico , Ozônio/análise , Polônia/epidemiologia , Estudos Prospectivos
6.
Exp Parasitol ; 256: 108649, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37914152

RESUMO

Type 1 diabetes mellitus is a chronic disease caused by the destruction of pancreatic beta cells. Based on the hygiene hypothesis, a growing body of evidence suggests a negative association between parasitic infections and diabetes in humans and animal models. The mechanism of parasite-mediated prevention of type 1 diabetes mellitus may be related to the adaptive and innate immune systems. Macrophage polarization is a new paradigm for the treatment of type 1 diabetes mellitus, and different host macrophage subsets play various roles during parasite infection. Proinflammatory cytokines are released by M1 macrophages, which are important in the development of type 1 diabetes mellitus. Parasite-activated M2 macrophages prevent the development of type 1 diabetes mellitus and can influence the development of adaptive immune responses through several mechanisms, including Th2 cells and regulatory T cells. Here, we review the role and mechanism of macrophage polarization in parasitic protection against type 1 diabetes mellitus.


Assuntos
Diabetes Mellitus Tipo 1 , Parasitos , Doenças Parasitárias , Humanos , Animais , Diabetes Mellitus Tipo 1/prevenção & controle , Macrófagos , Citocinas , Células Th2 , Ativação de Macrófagos
7.
Parasitol Int ; 98: 102818, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37848126

RESUMO

The study of immune regulation mechanisms induced by parasites may help develop new treatment methods for inflammatory diseases including type 1 diabetes, which is related to type 1 immune responses. The negative correlation between schistosomiasis infection and type 1 diabetes has been confirmed, and the mechanism of Schistosoma-mediated prevention of type 1 diabetes may be related to the adaptive and innate immune systems. Schistosoma-related molecules affect immune cell composition and macrophage polarization and stimulate an increase in natural killer T cells. Furthermore, Schistosoma-related molecules can regulate the adaptive immune responses related to the prevention of type 1 diabetes and change the Th1/Th2 and Th17/Treg axis. Our previous review showed the role of regulatory T cells in the protective of type 1 diabetes mediated by Schistosoma. Here, we aim to review the other mechanisms of schistosomiasis infection and Schistosoma-related products in regulating the immune response associated with the treatment of type 1 diabetes.


Assuntos
Diabetes Mellitus Tipo 1 , Esquistossomose , Animais , Diabetes Mellitus Tipo 1/prevenção & controle , Schistosoma , Linfócitos T Reguladores , Antígenos de Helmintos , Citocinas
8.
Probl Sotsialnoi Gig Zdravookhranenniiai Istor Med ; 31(Special Issue 2): 1189-1196, 2023 Oct.
Artigo em Russo | MEDLINE | ID: mdl-38069884

RESUMO

The exact etiology and mechanisms that trigger the development of type 1 diabetes mellitus (DM1) are not conclusively studied. However, there is increasing scientific evidence that damage to pancreatic islet cells (ß-cells) in genetically predisposed individuals is initiated by environmental factors. Currently, the main tactic of DM1 treatment at the stage of clinical manifestations is based on insulin replacement therapy. The introduction of modern insulin drugs and devices for its delivery, as well as continuous glucose monitoring systems into medical practice does not relieve patients from the need to take this hormone for life. Therefore, the development of methods to prevent DM1 remains the main task of diabetes research. The purpose of this article was to review current preventive strategies aimed at preventing or stopping the progression of DM1 in high-risk individuals. This article was prepared based on a review of current publications from the PubMed bibliographic database. The article discusses strategies targeting environmental triggers, methods to regulate the immune response using current cellular approaches and novel autoantigens, as well as off-target effects of the BCG vaccine and general principles of personalized prevention.


Assuntos
Diabetes Mellitus Tipo 1 , Humanos , Autoantígenos/uso terapêutico , Glicemia , Automonitorização da Glicemia , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/prevenção & controle , Insulina/uso terapêutico
9.
Life Sci ; 335: 122274, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37979832

RESUMO

AIMS: Extra virgin olive oil (EVOO) is the highest quality olive oil available and has been shown to regulate postprandial blood glucose in patients with type 1 diabetes (T1D). However, it remains uncertain whether EVOO can prevent the onset of T1D. In this study, we investigated the potential preventive effect of orally administered EVOO on T1D in non-obese diabetic (NOD) mice. MAIN METHODS: We analyzed changes in fecal microbes using 16 s rDNA sequencing and serum metabolites using Ultra High-Performance Liquid Chromatography and Quadrupole Time-of-Flight Mass Spectrometry (Q-TOF-MS). KEY FINDINGS: Our findings showed that EVOO supplementation in NOD mice slowed gastric emptying, reduced insulitis, and delayed T1D onset. Moreover, EVOO altered the composition of fecal microbes, increasing the Bacteroidetes/Firmicutes ratio, and promoting the growth of short-chain fatty acids (SCFAs)-producing bacteria, such as Lachnoclostridium and Ruminococcaceae_UCG-005. Moreover, it also increased beneficial serum metabolites, including unsaturated fatty acid and triterpenoid, which positively correlated with the increased SCFA-producing bacteria and negatively correlated with the disease indicators. Conversely, most decreased serum lipid metabolites, such as Oleamide, showed the opposite trend. SIGNIFICANCE: Our study demonstrates that EVOO may ameliorate pancreas inflammation and prevent T1D onset in NOD mice by modulating gut microbiota and serum metabolites.


Assuntos
Diabetes Mellitus Tipo 1 , Microbioma Gastrointestinal , Camundongos , Animais , Humanos , Camundongos Endogâmicos NOD , Diabetes Mellitus Tipo 1/prevenção & controle , Azeite de Oliva/farmacologia , Suplementos Nutricionais
10.
Life Sci ; 335: 122273, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37972884

RESUMO

AIMS: To investigate the potential of imDCs with high expression of HO-1 in preventing or delaying the onset of Type 1 diabetes mellitus (T1DM) in non-obese diabetic (NOD) mice. MATERIALS AND METHODS: The phenotypic features of DCs in each group were assessed using flow cytometry. Western blot analysis was used to confirm the high expression of HO-1 in imDCs induced with CoPP. Additionally, flow cytometry was used to evaluate the suppressive capacity of CoPP-induced imDCs on splenic lymphocyte proliferation. Finally, the preventive effect of CoPP-induced imDCs was tested in NOD mice. KEY FINDINGS: Compared to imDCs, CoPP-induced imDCs exhibited a reduced mean fluorescence intensity (MFI) of the co-stimulatory molecule CD80 on their surface (P < 0.05) and significantly increased HO-1 protein expression (P < 0.05). Following LPS stimulation, the MFI of co-stimulatory molecules CD80 and CD86 on the surface of CoPP-induced imDCs remained at a lower level (P < 0.05). Furthermore, there was a reduced proliferation rate of lymphocytes stimulated with anti-CD3/28 antibodies. The adoptive transfer of CoPP-imDCs significantly reduced the incidence of T1DM (16.66 % vs. control group: 66.67 %, P = 0.004). Furthermore, at 15 weeks of age, the insulitis score was also decreased in the CoPP-induced imDC treatment group (P < 0.05). There were no significant differences in serum insulin levels among all groups. SIGNIFICANCE: ImDCs induced with CoPP and exhibiting high expression of HO-1 demonstrate a robust ability to inhibit immune responses and effectively reduce the onset of diabetes in NOD mice. This finding suggests that CoPP-induced imDCs could potentially serve as a promising treatment strategy for T1DM.


Assuntos
Diabetes Mellitus Tipo 1 , Animais , Camundongos , Transferência Adotiva , Células Cultivadas , Células Dendríticas , Diabetes Mellitus Tipo 1/prevenção & controle , Diabetes Mellitus Tipo 1/metabolismo , Heme Oxigenase-1/metabolismo , Camundongos Endogâmicos NOD
12.
IEEE Pulse ; 14(4): 19-23, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37983136

RESUMO

In The U.K., a heated debate is raging in the genetics community about a not-so-new technology and its role in public health. Cheap genetic tests to discover our ancestry have become familiar consumer products, and our genes can tell us a lot about our ancestry, so it is an appealing idea that they can tell us about our susceptibility to serious diseases. Polygenic risk scores (PRS)-generated by sequencing multiple parts of a person's DNA-are said by some to hold the key to helping people avoid everything from type 1 diabetes to cardiovascular disease and cancer. This could herald a new era of preventive medicine, and the U.K. is investing heavily, but ultimately, whether or not this a good investment is still being determined.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 1 , Humanos , Testes Genéticos , Fatores de Risco , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/prevenção & controle , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/prevenção & controle , DNA
13.
Pediatr Endocrinol Diabetes Metab ; 29(3): 196-201, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38031834

RESUMO

Type 1 diabetes (T1D) is an autoimmune disorder, and insulin deficiency is the result of b-cell dysfunction. Treatment of type 1 diabetes requires constant parenteral insulin administration, which can be very burdensome for the patient. Meticulous use of insulin therapy does not protect the patient against complications. Hence, the search for other methods of treatment as well as ways of preventing the onset of diabetes has been ongoing for a long time. The main obstacle in the implementation of the prevention task is the need to identify people at risk of developing diabetes before the start of autoimmunity. It seems that primary prevention is still unrealistic at the moment, because we do not know all the factors leading to the activation of autoimmunity processes. Research on the use of late secondary prevention in people who develop glucose tolerance disorders or in the early period after the onset of type 1 diabetes are at the most advanced stage. Gene therapy is another attempt at an alternative treatment and prevention of type 1 diabetes and still requires further research. Recent years have brought a lot of information about the nature of type 1 diabetes and the mechanisms leading to its development. However, it has not yet been established what factors decide about the initiation of autoimmunity and what determines the dynamics of these processes.


Assuntos
Diabetes Mellitus Tipo 1 , Humanos , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/prevenção & controle , Insulina/uso terapêutico , Autoimunidade
14.
Nutrients ; 15(20)2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37892409

RESUMO

AIMS AND HYPOTHESIS: The incidence of type 1 diabetes mellitus in children is considerably increasing in western countries. Thus, identification of the environmental determinants involved could ultimately lead to disease prevention. Here, we aimed to systematically review (PROSPERO ID: CRD42022362522) the current evidence of the association between maternal dietary factors during gestation and the risk of developing type 1 diabetes and/or islet autoimmunity (IA) in murine and human offspring. METHODS: In accordance with PRISMA guidelines, the present systematic review searched PubMed and Scopus (n = 343) for different combinations of MeSH terms, such as type 1 diabetes, diet, islet autoimmunity, prenatal, nutrient, gluten, gliadin, vitamin, milk, and fibers. RESULTS: We found that the most investigated dietary factors in the present literature were gluten, dietary advanced glycosylated end products (dAGEs), vitamin D, fatty acids, and iron. The results concerning prenatal exposure to a gluten-free environment showed a consistently protective effect on the development of IA. Prenatal exposures to vitamin D and certain fatty acids appeared to protect against the development of IA, whereas in utero iron and fat exposures correlated with increased risks of IA. CONCLUSION: We conclude that a definite association is not established for most factors investigated as the literature represents a heterogeneous pool of data, although fetal exposures to some maternal dietary components, such as gluten, show consistent associations with increased risks of IA. We suggest that human prospective dietary intervention studies in both cohort and clinical settings are crucial to better evaluate critical and protective prenatal exposures from the maternal diet during pregnancy.


Assuntos
Diabetes Mellitus Tipo 1 , Ilhotas Pancreáticas , Criança , Gravidez , Feminino , Humanos , Animais , Camundongos , Diabetes Mellitus Tipo 1/etiologia , Diabetes Mellitus Tipo 1/prevenção & controle , Diabetes Mellitus Tipo 1/epidemiologia , Autoimunidade , Vitamina D , Vitaminas , Ácidos Graxos , Glutens , Ferro , Autoanticorpos , Fatores de Risco
15.
Front Immunol ; 14: 1227133, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37731505

RESUMO

Introduction: In this study, we report a novel therapeutic approach using B lymphocytes to attract islet-specific T cells in the non-obese diabetic (NOD) mouse model and prevent the development of autoimmune diabetes. Rather than using the antibody receptor of B cells, this approach utilizes their properties as antigen-presenting cells to T cells. Methods: Purified splenic B cells were treated with lipopolysaccharide, which increases regulatory B (Breg) cell function, then electroporated with mRNA encoding either chimeric MHC-I or MHC-II molecules covalently linked to antigenic peptides. Immunoregulatory functions of these engineered B cells (e-B cells) were tested by in vitro assays and in vivo co-transfer experiments with beta-cell-antigen-specific CD8+ or CD4+ T cells in NOD.Scid mice, respectively. Results: The e-B cells expressing chimeric MHC-I-peptide inhibited antigen-specific CD8+ T-cell cytotoxicity in vitro. The e-B cells expressing chimeric MHC-II-peptide induced antigen-specific CD4+ T cells to express the regulatory markers, PD-1, ICOS, CTLA-4, Lag3, and Nrp1. Furthermore, e-B cells encoding the chimeric MHC-I and MHC-II peptide constructs protected NOD.Scid mice from autoimmune diabetes induced by transfer of antigen-specific CD8+ and CD4+ T cells. Discussion: MHC-peptide chimeric e-B cells interacted with pathogenic T cells, and protected the host from autoimmune diabetes, in a mouse model. Thus, we have successfully expressed MHC-peptide constructs in B cells that selectively targeted antigen-specific cells, raising the possibility that this strategy could be used to endow different protective cell types to specifically regulate/remove pathogenic cells.


Assuntos
Linfócitos B Reguladores , Diabetes Mellitus Tipo 1 , Ilhotas Pancreáticas , Imunodeficiência Combinada Severa , Camundongos , Animais , Diabetes Mellitus Tipo 1/prevenção & controle , Camundongos Endogâmicos NOD , Camundongos SCID , Antígenos de Histocompatibilidade Classe II
16.
J Clin Invest ; 133(18)2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37561596

RESUMO

Adoptive immunotherapy with Tregs is a promising approach for preventing or treating type 1 diabetes. Islet antigen-specific Tregs have more potent therapeutic effects than polyclonal cells, but their low frequency is a barrier for clinical application. To generate Tregs that recognize islet antigens, we engineered a chimeric antigen receptor (CAR) derived from a monoclonal antibody with specificity for the insulin B chain 10-23 peptide presented in the context of the IAg7 MHC class II allele present in NOD mice. Peptide specificity of the resulting InsB-g7 CAR was confirmed by tetramer staining and T cell proliferation in response to recombinant or islet-derived peptide. The InsB-g7 CAR redirected NOD Treg specificity such that insulin B 10-23-peptide stimulation enhanced suppressive function, measured via reduction of proliferation and IL-2 production by BDC2.5 T cells and CD80 and CD86 expression on dendritic cells. Cotransfer of InsB-g7 CAR Tregs prevented adoptive transfer diabetes by BDC2.5 T cells in immunodeficient NOD mice. In WT NOD mice, InsB-g7 CAR Tregs prevented spontaneous diabetes. These results show that engineering Treg specificity for islet antigens using a T cell receptor-like CAR is a promising therapeutic approach for the prevention of autoimmune diabetes.


Assuntos
Diabetes Mellitus Tipo 1 , Receptores de Antígenos Quiméricos , Camundongos , Animais , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/prevenção & controle , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/metabolismo , Camundongos Endogâmicos NOD , Insulina/metabolismo , Linfócitos T Reguladores
17.
Int. microbiol ; 26(3): 675-690, Ene-Agos, 2023. ilus, tab, graf
Artigo em Inglês | IBECS | ID: ibc-223992

RESUMO

Type 1 diabetes mellitus (T1DM) has been increasing in prevalence in the last decades and has become a global burden. Autoantibodies against human glutamate decarboxylase (GAD65) are among the first to be detected at the onset of T1DM. Diverse viruses have been proposed to be involved in the triggering of T1DM because of molecular mimicry, i.e., similarity between parts of some viral proteins and one or more epitopes of GAD65. However, the possibility that bacterial proteins might also be responsible for GAD65 mimicry has been seldom investigated. To date, many genomes of Streptococcus pneumoniae (the pneumococcus), a prominent human pathogen particularly prevalent among children and the elderly, have been sequenced. A dataset of more than 9000 pneumococcal genomes was mined and two different (albeit related) genes (gadA and gadB), presumably encoding two glutamate decarboxylases similar to GAD65, were found. The various gadASpn alleles were present only in serotype 3 pneumococci belonging to the global lineage GPSC83, although some homologs have also been discovered in two subspecies of Streptococcus constellatus (pharyngis and viborgensis), an isolate of the group B streptococci, and several strains of Lactobacillus delbrueckii. Besides, gadBSpn alleles are present in > 10% of the isolates in our dataset and represent 16 GPSCs with 123 sequence types and 20 different serotypes. Sequence analyses indicated that gadA- and gadB-like genes have been mobilized among different bacteria either by prophage(s) or by integrative and conjugative element(s), respectively. Substantial similarities appear to exist between the putative pneumococcal glutamate decarboxylases and well-known epitopes of GAD65. In this sense, the use of broader pneumococcal conjugate vaccines such as PCV20 would prevent the majority of serotypes expressing those genes that might potentially contribute to T1DM.(AU)


Assuntos
Humanos , Streptococcus pneumoniae/genética , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/microbiologia , Glutamato Descarboxilase/genética , Mimetismo Molecular , Vacinas Pneumocócicas , Microbiologia , Técnicas Microbiológicas , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/prevenção & controle
18.
Cells ; 12(12)2023 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-37371037

RESUMO

The incidence of the autoimmune disease type 1 diabetes is increasing, likely caused by environmental factors. A gluten-free diet has previously been shown to ameliorate autoimmune diabetes in non-obese diabetic (NOD) mice and humans. Although the exact mechanisms are not understood, interventions influencing the intestinal microbiota early in life affect the risk of type 1 diabetes. Here, we characterize how NOD mice that are fed a gluten-free (GF) diet differ from NOD mice that are fed a gluten-containing standard (STD) diet in terms of their microbiota composition by 16S rRNA gene amplicon sequencing and pancreatic immune environment by real-time quantitative PCR at the prediabetic stage at 6 and 13 weeks of age. Gut microbiota analysis revealed highly distinct microbiota compositions in both the cecum and the colon of GF-fed mice compared with STD-fed mice. The microbiotas of the GF-fed mice were characterized by an increased Firmicutes/Bacteroidetes ratio, an increased abundance of short chain fatty acid (particularly butyrate)-producing bacteria, and a reduced abundance of Lactobacilli compared with STD mice. We found that the insulitis score in the GF mice was significantly reduced compared with the STD mice and that the markers for regulatory T cells and T helper 2 cells were upregulated in the pancreas of the GF mice. In conclusion, a GF diet during pre- and early post-natal life induces shifts in the cecal and colonic microbiota compatible with a less inflammatory environment, providing a likely mechanism for the protective effect of a GF diet in humans.


Assuntos
Diabetes Mellitus Tipo 1 , Dieta Livre de Glúten , Estado Pré-Diabético , Animais , Feminino , Camundongos , Gravidez , Bactérias , Diabetes Mellitus Tipo 1/prevenção & controle , Camundongos Endogâmicos NOD , Estado Pré-Diabético/prevenção & controle , RNA Ribossômico 16S/genética , Linfócitos T Reguladores , Microbioma Gastrointestinal
20.
Artigo em Inglês | MEDLINE | ID: mdl-37297566

RESUMO

Nowadays, the development of new immuno-therapeutic drugs has made it possible to alter the course of many autoimmune diseases. Type 1 diabetes is a chronic disease with a progressive dependence on exogenous insulin administration. The ability to intercept individuals at high risk of developing type 1 diabetes is the first step toward the development of therapies that can delay the process of ß-cell destruction, thus permitting a better glycemic control and reducing the incidence of ketoacidosis. The knowledge of the main pathogenetic mechanisms underlying the three stages of the disease may be helpful to identify the best immune therapeutic approach. In this review, we aim to give an overview of the most important clinical trials conducted during the primary, secondary and tertiary phases of prevention.


Assuntos
Doenças Autoimunes , Diabetes Mellitus Tipo 1 , Células Secretoras de Insulina , Humanos , Criança , Diabetes Mellitus Tipo 1/prevenção & controle , Diabetes Mellitus Tipo 1/tratamento farmacológico , Insulina/uso terapêutico , Doença Crônica , Autoimunidade
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