Altering β Cell Antigen Exposure to Exhausted CD8+ T Cells Prevents Autoimmune Diabetes in Mice.

Chronic destruction of insulin-producing pancreatic β cells by T cells results in autoimmune diabetes. Similar to other chronic T cell-mediated pathologies, a role for T cell exhaustion has been identified in diabetes in humans and NOD mice. The development and differentiation of exhausted T cells depends on exposure to Ag.

TIGIT acts as an immune checkpoint upon inhibition of PD1 signaling in autoimmune diabetes.

Introduction: Chronic activation of self-reactive T cells with beta cell antigens results in the upregulation of immune checkpoint molecules that keep self-reactive T cells under control and delay beta cell destruction in autoimmune diabetes. Inhibiting PD1/PD-L1 signaling results in autoimmune diabetes in mice and humans with pre-existing autoimmunity against beta cells. However, it is not known if other immune checkpoint molecules, such as TIGIT, can also negatively regulate self-reactive T cells.

Simplified gestational diabetes screening with a triaging fasting plasma glucose reduces the burden of oral glucose tolerance tests during pregnancy - A large tertiary comparative cohort study.

Aims: The study aimed to evaluate the impact of a simplified screeningapproach for gestational diabetes (GDM) compared to conventional screening on OGTT rates, GDM prevalence, and perinatal outcomes.

Method: A retrospective comparative cohort study included singleton births from 20 weeks' gestation. Pregnancies without diagnostic glucose results from 13 weeks' gestation or incomplete screenings were excluded.

Increased Thyroidal Activity on Routine FDG-PET/CT after Combination Immune Checkpoint Inhibition: Temporal Associations with Clinical and Biochemical Thyroiditis.

Background: FDG-PET/CT used for immune checkpoint inhibitor (ICI) response assessment can incidentally identify immune-related adverse events (irAEs), including thyroiditis. This study aimed to correlate the time course of FDG-PET/CT evidence of thyroiditis with clinical and biochemical evolution of thyroid dysfunction.

Methods: A retrospective review was performed by two independent blinded nuclear medicine physicians (NMPs) of thyroidal FDG uptake in 127 patients who underwent PET/CT between January 2016 and January 2019 at baseline and during treatment monitoring of combination ICI therapy for advanced melanoma.

Imaging for assessment of cancer treatment response to immune checkpoint inhibitors can be complementary in identifying hypophysitis.

Introduction: Hypophysitis is reported in 8.5%-14% of patients receiving combination immune checkpoint inhibition (cICI) but can be a diagnostic challenge. This study aimed to assess the role of routine diagnostic imaging performed during therapeutic monitoring of combination anti-CTLA-4/anti-PD-1 treatment in the identification of hypophysitis and the relationship of imaging findings to clinical diagnostic criteria.

Continuous Glucose Monitoring-Based Composite Metrics: A Review and Assessment of Performance in Recent-Onset and Long-Duration Type 1 Diabetes.

This study examined correlations between continuous glucose monitoring (CGM)-based composite metrics and standard glucose metrics within CGM data sets from individuals with recent-onset and long-duration type 1 diabetes. First, a literature review and critique of published CGM-based composite metrics was undertaken. Second, composite metric results were calculated for the two CGM data sets and correlations with six standard glucose metrics were examined.

Interferons limit autoantigen-specific CD8 T-cell expansion in the non-obese diabetic mouse.

Interferon gamma (IFNγ) is a proinflammatory cytokine implicated in autoimmune diseases. However, deficiency or neutralization of IFNγ is ineffective in reducing disease. We characterize islet antigen-specific T cells in non-obese diabetic (NOD) mice lacking all three IFN receptor genes.

Case Report: Hypoglycemia Due to a Novel Activating Glucokinase Variant in an Adult - a Molecular Approach.

We present a case of an obese 22-year-old man with activating variant who had neonatal hypoglycemia, re-emerging with hypoglycemia later in life. We investigated him for asymptomatic hypoglycemia with a family history of hypoglycemia. Genetic testing yielded a novel missense class 3 variant that was subsequently found in his mother, sister and nephew and reclassified as a class 4 likely pathogenic variant.

Severe acute respiratory syndrome coronavirus 2 as a potential cause of type 1 diabetes facilitated by spike protein receptor binding domain attachment to human islet cells: An illustrative case study and experimental data.

Aims: Aim of this study is to report severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, responsible for coronavirus disease 2019 (COVID-19), as a possible cause for type 1 diabetes by providing an illustrative clinical case of a man aged 45 years presenting with antibody-negative diabetic ketoacidosis post-recovery from COVID-19 pneumonia and to explore the potential for SARS-CoV-2 to adhere to human islet cells.

Methods: Explanted human islet cells from three independent solid organ donors were incubated with the SARS-CoV-2 spike protein receptor biding domain (RBD) fused to a green fluorescent protein (GFP) or a control-GFP, with differential adherence established by flow cytometry.

Results: Flow cytometry revealed dose-dependent specific binding of RBD-GFP to islet cells when compared to control-GFP.

Tolerance to Proinsulin-1 Reduces Autoimmune Diabetes in NOD Mice.

T-cell responses to insulin and its precursor proinsulin are central to islet autoimmunity in humans and non-obese diabetic (NOD) mice that spontaneously develop autoimmune diabetes. Mice have two proinsulin genes proinsulin -1 and 2 that are differentially expressed, with predominant proinsulin-2 expression in the thymus and proinsulin-1 in islet beta-cells. In contrast to proinsulin-2, proinsulin-1 knockout NOD mice are protected from autoimmune diabetes.

Reducing adverse events associated with the glucagon stimulation test for the assessment of growth hormone deficiency in adults with a high prevalence of pituitary hormone deficiencies.

Design: A retrospective review of the adverse events (AEs) in 78 patients during the glucagon stimulation test (GST) for the assessment of growth hormone deficiency (GHD) before and after protocol amendments which aimed to reduce AEs in a group of patients with a high prevalence of pituitary hormone deficiencies.

Patients: Based on our observations of frequent AEs during the standard GST protocol in an initial 25 patients (cohort 1), a modified protocol was introduced to include the routine administration of 20 mg of hydrocortisone pre-GST in a subsequent 53 patients (cohort 2). Post hoc analysis of the effect of glucocorticoid dosing pre-GST on AEs was examined in those receiving <20 mg hydrocortisone (group A, n = 19) vs ≥20 mg hydrocortisone (group B, n = 59).

Harnessing CD8 T-cell exhaustion to treat type 1 diabetes.

Although immune interventions have shown great promise in type 1 diabetes mellitus (T1D) clinical trials, none are yet in routine clinical use or able to achieve insulin independence in patients. In addition to this, the principles of T1D treatment remain essentially unchanged since the isolation of insulin, almost a century ago. T1D is characterized by insulin deficiency as a result of destruction of insulin-producing beta cells mediated by autoreactive T cells.

Deficiency of the innate immune adaptor STING promotes autoreactive T cell expansion in NOD mice.

Aims/hypothesis: Stimulator of IFN genes (STING) is a central hub for cytosolic nucleic acid sensing and its activation results in upregulation of type I IFN production in innate immune cells. A type I IFN gene signature seen before the onset of type 1 diabetes has been suggested as a driver of disease initiation both in humans and in the NOD mouse model. A possible source of type I IFN is through activation of the STING pathway.

Soluble FAS ligand is not required for pancreatic islet inflammation or beta-cell destruction in non-obese diabetic mice.

CD8 T cells play a central role in beta-cell destruction in type 1 diabetes. CD8 T cells use two main effector pathways to kill target cells, perforin plus granzymes and FAS ligand (FASL). We and others have established that in non-obese diabetic (NOD) mice, perforin is the dominant effector molecule by which autoreactive CD8 T cells kill beta cells.