scholarly journals Do viral infections protect from or enhance type 1 diabetes and how can we tell the difference?

2011 ◽  
Vol 8 (3) ◽  
pp. 193-198 ◽  
Author(s):  
Urs Christen ◽  
Matthias G von Herrath
2021 ◽  
Vol 9 (7) ◽  
pp. 1519
Author(s):  
Sonia R. Isaacs ◽  
Dylan B. Foskett ◽  
Anna J. Maxwell ◽  
Emily J. Ward ◽  
Clare L. Faulkner ◽  
...  

For over a century, viruses have left a long trail of evidence implicating them as frequent suspects in the development of type 1 diabetes. Through vigorous interrogation of viral infections in individuals with islet autoimmunity and type 1 diabetes using serological and molecular virus detection methods, as well as mechanistic studies of virus-infected human pancreatic β-cells, the prime suspects have been narrowed down to predominantly human enteroviruses. Here, we provide a comprehensive overview of evidence supporting the hypothesised role of enteroviruses in the development of islet autoimmunity and type 1 diabetes. We also discuss concerns over the historical focus and investigation bias toward enteroviruses and summarise current unbiased efforts aimed at characterising the complete population of viruses (the “virome”) contributing early in life to the development of islet autoimmunity and type 1 diabetes. Finally, we review the range of vaccine and antiviral drug candidates currently being evaluated in clinical trials for the prevention and potential treatment of type 1 diabetes.


2021 ◽  
Vol 9 (6) ◽  
pp. 1177
Author(s):  
Abdulaziz Alhazmi ◽  
Magloire Pandoua Nekoua ◽  
Hélène Michaux ◽  
Famara Sane ◽  
Aymen Halouani ◽  
...  

The thymus gland is a primary lymphoid organ for T-cell development. Various viral infections can result in disturbance of thymic functions. Medullary thymic epithelial cells (mTECs) are important for the negative selection of self-reactive T-cells to ensure central tolerance. Insulin-like growth factor 2 (IGF2) is the dominant self-peptide of the insulin family expressed in mTECs and plays a crucial role in the intra-thymic programing of central tolerance to insulin-secreting islet β-cells. Coxsackievirus B4 (CVB4) can infect and persist in the thymus of humans and mice, thus hampering the T-cell maturation and differentiation process. The modulation of IGF2 expression and protein synthesis during a CVB4 infection has been observed in vitro and in vivo in mouse models. The effect of CVB4 infections on human and mouse fetal thymus has been studied in vitro. Moreover, following the inoculation of CVB4 in pregnant mice, the thymic function in the fetus and offspring was disturbed. A defect in the intra-thymic expression of self-peptides by mTECs may be triggered by CVB4. The effects of viral infections, especially CVB4 infection, on thymic cells and functions and their possible role in the pathogenesis of type 1 diabetes (T1D) are presented.


Open Medicine ◽  
2009 ◽  
Vol 4 (4) ◽  
pp. 415-422
Author(s):  
Kamile Gul ◽  
Ihsan Ustun ◽  
Yusuf Aydin ◽  
Dilek Berker ◽  
Halil Erol ◽  
...  

AbstractThe aim of the study was to determine the frequency and titers of anti-thyroid peroxidase (Anti-TPO), anti-thyroglobulin (Anti-TG), and anti-glutamic acid decarboxylase (Anti-GAD) antibodies in Turkish patients with type 1 diabetes mellitus (DM), and to compare the frequency of anti-TPO and anti-TG titers in the presence or absence of anti-GAD. A total of 104 patients including 56 males and 48 females with type 1 DM and their age-, gender-, and body mass index-matched control group, including 31 males and 27 females, 58 cases in total with an age range of 15-50 years, were recruited into this study. In patients with type 1 DM, positive anti-GAD was detected in 30.8% (n=32). In patients with positive anti-GAD, rate of positive anti-TPO was 37.5%; however, in patients with negative anti-GAD, the rate of positive anti-TPO was 9.7% and the difference was statistically significant (p=0.001). In patients with positive anti-GAD, the rate of positive anti-TG was 18.8%. In patients with negative anti-GAD, the rate of positive anti-TG was 2.8%, and the difference between them was statistically significant (p=0.005). In patients with positive and negative anti-GAD, rates of both positive anti-TPO and anti-TG were 15.6% and 1.4%, respectively, with the difference showing statistical significance (p=0.004). Thyroid autoimmunity in type 1 DM patients with positive anti-GAD was apparently higher; therefore, these patients should be followed more frequently and carefully.


Author(s):  
Hermann E. Wasmuth ◽  
Gregor Hess ◽  
Christoph Viergutz ◽  
Helmut R. Henrichs ◽  
Stephan Martin ◽  
...  

2015 ◽  
Vol 309 (5) ◽  
pp. E474-E486 ◽  
Author(s):  
Ling Hinshaw ◽  
Ashwini Mallad ◽  
Chiara Dalla Man ◽  
Rita Basu ◽  
Claudio Cobelli ◽  
...  

Glucagon use in artificial pancreas for type 1 diabetes (T1D) is being explored for prevention and rescue from hypoglycemia. However, the relationship between glucagon stimulation of endogenous glucose production (EGP) viz., hepatic glucagon sensitivity, and prevailing glucose concentrations has not been examined. To test the hypothesis that glucagon sensitivity is increased at hypoglycemia vs. euglycemia, we studied 29 subjects with T1D randomized to a hypoglycemia or euglycemia clamp. Each subject was studied at three glucagon doses at euglycemia or hypoglycemia, with EGP measured by isotope dilution technique. The peak EGP increments and the integrated EGP response increased with increasing glucagon dose during euglycemia and hypoglycemia. However, the difference in dose response based on glycemia was not significant despite higher catecholamine concentrations in the hypoglycemia group. Knowledge of glucagon's effects on EGP was used to develop an in silico glucagon action model. The model-derived output fitted the obtained data at both euglycemia and hypoglycemia for all glucagon doses tested. Glucagon clearance did not differ between glucagon doses studied in both groups. Therefore, the glucagon controller of a dual hormone control system may not need to adjust glucagon sensitivity, and hence glucagon dosing, based on glucose concentrations during euglycemia and hypoglycemia.


2018 ◽  
Vol 43 (6) ◽  
pp. 541-552 ◽  
Author(s):  
Nicole K. Brockman ◽  
Jane E. Yardley

Sex-related differences in metabolic and neuroendocrine response to exercise in individuals without diabetes have been well established. Men and women differ in fuel selection during exercise, in which women rely to a greater extent on fat oxidation, whereas males rely mostly on carbohydrate oxidation for energy production. The difference in fuel selection appears to be mediated by sex-related differences in hormonal (including catecholamines, growth hormone, and estrogen) response to different types and intensities of exercise. In general, men exhibit an amplified counter-regulatory response to exercise, with elevated levels of catecholamines compared with women. However, women exhibit greater sensitivity to the lipolytic action of the catecholamines and deplete less of their glycogen stores than men during exercise, which suggests that women may experience a greater defense in blood glucose control after exercise than men. Conversely, little is known about sex-related differences in response to exercise in individuals with type 1 diabetes (T1D). A single study investigating sex-related differences in response to moderate aerobic exercise in individuals with T1D found sex-related differences in catecholamine response and fuel selection, but changes in blood glucose were not measured. To our knowledge, there are no studies investigating sex-related differences in blood glucose responses to different types and intensities of exercise in individuals with T1D. This review summarizes sex-related differences in exercise responses that could potentially impact blood glucose levels during exercise in individuals with T1D and highlights the need for further research.


2016 ◽  
Vol 5 (3) ◽  
pp. 136-142 ◽  
Author(s):  
M Boering ◽  
P R van Dijk ◽  
S J J Logtenberg ◽  
K H Groenier ◽  
B H R Wolffenbuttel ◽  
...  

Aims Elevated sex hormone-binding globulin (SHBG) concentrations have been described in patients with type 1 diabetes mellitus (T1DM), probably due to low portal insulin concentrations. We aimed to investigate whether the route of insulin administration, continuous intraperitoneal insulin infusion (CIPII), or subcutaneous (SC), influences SHBG concentrations among T1DM patients. Methods Post hoc analysis of SHBG in samples derived from a randomized, open-labeled crossover trial was carried out in 20 T1DM patients: 50% males, mean age 43 (±13) years, diabetes duration 23 (±11) years, and hemoglobin A1c (HbA1c) 8.7 (±1.1) (72 (±12) mmol/mol). As secondary outcomes, testosterone, 17-β-estradiol, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were analyzed. Results Estimated mean change in SHBG was −10.3nmol/L (95% CI: −17.4, −3.2) during CIPII and 3.7nmol/L (95% CI: −12.0, 4.6) during SC insulin treatment. Taking the effect of treatment order into account, the difference in SHBG between therapies was −6.6nmol/L (95% CI: −17.5, 4.3); −12.7nmol/L (95% CI: −25.1, −0.4) for males and −1.7nmol/L (95% CI: −24.6, 21.1) for females, respectively. Among males, SHBG and testosterone concentrations changed significantly during CIPII; −15.8nmol/L (95% CI: −24.2, −7.5) and −8.3nmol/L (95% CI: −14.4, −2.2), respectively. The difference between CIPII and SC insulin treatment was also significant for change in FSH 1.2U/L (95% CI: 0.1, 2.2) among males. Conclusions SHBG concentrations decreased significantly during CIPII treatment. Moreover, the difference in change between CIPII and SC insulin therapy was significant for SHBG and FSH among males. These findings support the hypothesis that portal insulin administration influences circulating SHBG and sex steroids.


2021 ◽  
Vol 12 ◽  
Author(s):  
Michele Mishto ◽  
Artem Mansurkhodzhaev ◽  
Teresa Rodriguez-Calvo ◽  
Juliane Liepe

Increasing evidence suggests that post-translational peptide splicing can play a role in the immune response under pathological conditions. This seems to be particularly relevant in Type 1 Diabetes (T1D) since post-translationally spliced epitopes derived from T1D-associated antigens have been identified among those peptides bound to Human Leucocyte Antigen (HLA) class I and II complexes. Their immunogenicity has been confirmed through CD4+ and CD8+ T cell-mediated responses in T1D patients. Spliced peptides theoretically have a large sequence variability. This might increase the frequency of viral-human zwitter peptides, i.e. peptides that share a complete sequence homology irrespective of whether they originate from human or viral antigens, thereby impinging upon the discrimination between self and non-self antigens by T cells. This might increase the risk of autoimmune responses triggered by viral infections. Since enteroviruses and other viral infections have historically been associated with T1D, we investigated whether cis-spliced peptides derived from selected viruses might be able to trigger CD8+ T cell-mediated autoimmunity. We computed in silico viral-human non-spliced and cis-spliced zwitter epitope candidates, and prioritized peptide candidates based on: (i) their binding affinity to HLA class I complexes, (ii) human pancreatic β cell and medullary thymic epithelial cell (mTEC) antigens’ mRNA expression, (iii) antigen association with T1D, and (iv) potential hotspot regions in those antigens. Neglecting potential T cell receptor (TCR) degeneracy, no viral-human zwitter non-spliced peptide was found to be an optimal candidate to trigger a virus-induced CD8+ T cell response against human pancreatic β cells. Conversely, we identified some zwitter peptide candidates, which may be produced by proteasome-catalyzed peptide splicing, and might increase the likelihood of pancreatic β cells recognition by virus-specific CD8+ T cell clones, therefore promoting β cell destruction in the context of viral infections.


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