Administration of Human Derived Upper gut Commensal Prevotella histicola delays the onset of type 1 diabetes in NOD mice

Background Type 1 diabetes (T1D) is an autoimmune disease that is increasing in prevalence worldwide. One of the contributing factors to the pathogenesis of T1D is the composition of the intestinal microbiota, as has been demonstrated. in T1D patients, with some studies demonstrating a deficiency in their levels of Prevotella. We have isolated a strain of Prevotella histicola from a duodenal biopsy that has anti-inflammatory properties, and in addition, alters the development of autoimmune diseases in mouse models. Therefore, our hypothesis is that the oral administration of P. histicola might delay the development of T1D in the non-obese diabetic (NOD) mice. To assess this, we used the following materials and methods. Female NOD mice (ages 5–8 weeks) were administered every other day P. histicola that was cultured in-house. Blood glucose levels were measured every other week. Mice were sacrificed at various time points for histopathological analysis of the pancreas. Modulation of immune response by the commensal was tested by analyzing regulatory T-cells and NKp46+ cells using flow cytometry and intestinal cytokine mRNA transcript levels using quantitative RT-PCR. For microbial composition, 16 s rRNA gene analysis was conducted on stool samples collected at various time points. Results Administration of P. histicola in NOD mice delayed the onset of T1D. Beta diversity in the fecal microbiomes demonstrated that the microbial composition of the mice administered P. histicola was different from those that were not treated. Treatment with P. histicola led to a significant increase in regulatory T cells with a concomitant decrease in NKp46+ cells in the pancreatic lymph nodes as compared to the untreated group after 5 weeks of treatment. Conclusions These observations suggest that P. histicola treatment delayed onset of diabetes by increasing the levels of regulatory T cells in the pancreatic lymph nodes. This preliminary work supports the rationale that enteral exposure to a non pathogenic commensal P. histicola be tested as a future therapy for T1D.

Reduced Follicular Regulatory T Cells in Spleen and Pancreatic Lymph Nodes of Patients With Type 1 Diabetes

In the attempt to understand the origin of autoantibody (AAb) production in patients with and at-risk for T1D, multiple studies have analyzed and reported alterations in follicular helper T cells (Tfh) in presymptomatic AAb-positive subjects and patients with T1D. Yet, it is still not clear whether the regulatory counterpart of Tfh cells, represented by follicular regulatory T cells (Tfr), is similarly altered. To address this question, we performed analyses in peripheral blood, spleen and pancreatic lymph nodes (PLN) of organ donor subjects with T1D. Blood analyses were also performed in living AAb-negative and -positive subjects. While negligible differences in the frequency and phenotype of blood Tfr cells were observed between T1D, AAb-negative and AAb-positive adult subjects, the frequency of Tfr cells was significantly reduced in spleen and PLN of T1D as compared to non-diabetic controls. Furthermore, adoptive transfer of Tfr cells delayed disease development in a mouse model of T1D, a finding that could indicate that Tfr cells play an important role in peripheral tolerance and regulation of autoreactive Tfh cells. Together, our findings provide evidence of Tfr cell alterations within disease-relevant tissues in patients with T1D suggesting a role for Tfr cells in defective humoral tolerance and disease pathogenesis.

Reduced Follicular Regulatory T Cells in Spleen and Pancreatic Lymph Nodes of Patients With Type 1 Diabetes

In the attempt to understand the origin of autoantibody (AAb) production in patients with and at-risk for T1D, multiple studies have analyzed and reported alterations in follicular helper T cells (Tfh) in presymptomatic AAb-positive subjects and patients with T1D. Yet, it is still not clear whether the regulatory counterpart of Tfh cells, represented by follicular regulatory T cells (Tfr), is similarly altered. To address this question, we performed analyses in peripheral blood, spleen and pancreatic lymph nodes (PLN) of organ donor subjects with T1D. Blood analyses were also performed in living AAb-negative and -positive subjects. While negligible differences in the frequency and phenotype of blood Tfr cells were observed between T1D, AAb-negative and AAb-positive adult subjects, the frequency of Tfr cells was significantly reduced in spleen and PLN of T1D as compared to non-diabetic controls. Furthermore, adoptive transfer of Tfr cells delayed disease development in a mouse model of T1D, a finding that could indicate that Tfr cells play an important role in peripheral tolerance and regulation of autoreactive Tfh cells. Together, our findings provide evidence of Tfr cell alterations within disease-relevant tissues in patients with T1D suggesting a role for Tfr cells in defective humoral tolerance and disease pathogenesis.

Reduced Follicular Regulatory T Cells in Spleen and Pancreatic Lymph Nodes of Patients With Type 1 Diabetes

In the attempt to understand the origin of autoantibody (AAb) production in patients with and at-risk for T1D, multiple studies have analyzed and reported alterations in follicular helper T cells (Tfh) in presymptomatic AAb-positive subjects and patients with T1D. Yet, it is still not clear whether the regulatory counterpart of Tfh cells, represented by follicular regulatory T cells (Tfr), is similarly altered. To address this question, we performed analyses in peripheral blood, spleen and pancreatic lymph nodes (PLN) of organ donor subjects with T1D. Blood analyses were also performed in living AAb-negative and -positive subjects. While negligible differences in the frequency and phenotype of blood Tfr cells were observed between T1D, AAb-negative and AAb-positive adult subjects, the frequency of Tfr cells was significantly reduced in spleen and PLN of T1D as compared to non-diabetic controls. Furthermore, adoptive transfer of Tfr cells delayed disease development in a mouse model of T1D, a finding that could indicate that Tfr cells play an important role in peripheral tolerance and regulation of autoreactive Tfh cells. Together, our findings provide evidence of Tfr cell alterations within disease-relevant tissues in patients with T1D suggesting a role for Tfr cells in defective humoral tolerance and disease pathogenesis.

Abnormal Cannabidiol protects pancreatic beta cells in mouse models of experimental Type 1 diabetes

ABSTRACTBackground and PurposeThe atypical cannabinoid Abn-CBD was reported to improve the inflammatory status in preclinical models of several pathologies including autoimmune diseases. However, its potential for autoimmune diabetes, i.e. type 1 diabetes (T1D), is unknown.Experimental ApproachWe used two mouse models of T1D, streptozotocin (STZ)-injected and non-obese diabetic (NOD) mice. Eight-to-ten-week-old male C57Bl6/J mice were pre-treated with Abn-CBD (1mg/kg of body weight) or vehicle for 1 week, following STZ treatment, and euthanized 1 week later. Six-week-old female NOD mice were treated with Abn-CBD (0.1-1mg/kg) or vehicle for 12 weeks and then euthanized. Blood, pancreas, pancreatic lymph nodes and circulating T cells were collected and processed for analysis. Glycemia was also monitored.Key ResultsAbn-CBD decreased circulating proinflammatory cytokines, ameliorated islet inflammation and the autoimmune attack, showing a 2-fold decrease in CD8+ T cells infiltration and reduced Th1/Th2 ratio in pancreatic lymph nodes of STZ-injected mice. Mechanistically, Abn-CBD reduced intra-islet phospho-NF-κB and TXNIP. Concomitant reduction of islet cell apoptosis and intra-islet fibrosis were observed in Abn-CBD pre-treated mice compared to vehicle. In NOD mice, Abn-CBD reduced the expression of Ifng, Il21, Tnfa and Il10 while increased Il4 in circulating CD4+ T cells compared to vehicle, reducing the severity of insulitis and improving glucose tolerance.Conclusion and ImplicationsAltogether, we found that Abn-CBD reduces intra-islet inflammation and delays the progression of insulitis in mouse models of T1D, preserving healthy functional islets. Hence, Abn-CBD and related compounds emerge as new candidates to develop pharmacological strategies to treat early stages of T1D.WHAT IS ALREADY KNOWN-Phytocannabinoids such as cannabidiol (CBD) have anti-inflammatory and glucose-lowering properties-The CBD derivative Abn-CBD ameliorates inflammation in various diseases and modulates beta cell functionWHAT THIS STUDY ADDS-Abn-CBD reduces systemic and pancreatic inflammation in mice models of type 1 diabetes-Abn-CBD prevents beta cell damage and loss during type 1 diabetes onsetCLINICAL SIGNIFICANCE-Synthetic cannabinoids emerge as potential treatment for type 1 diabetes

A DIAGNOSTIC PITFALL: PANCREATIC TUBERCULOSIS MASQUERADING AS PANCREATIC CARCINOMA

Isolated cases of Pancreatic Tuberculosis remains a rare entity even in countries with a high incidence of Tuberculosis. It presents as a hypoechoic mass on ultrasonography and imaging mimicking pancreatic malignancy. Consequently, it represents a diagnostic challenge both clinically (due to a similar array of symptoms) and radiologically. The diagnosis often requires tissue biopsy. The possibility of TB should be considered in the list of differential diagnoses of pancreatic mass and an endoscopic, ultrasound-guided biopsy might help to clinch the diagnosis of this potentially curable disease. Here, we report a case with symptoms of abdominal pain, progressive jaundice, and anorexia and weight loss, diagnosed to be a case of Disseminated Tuberculosis (Pancreatic TB) following Endoscopic Ultrasound guided FNAC of peri-pancreatic lymph nodes.

Expansion of Functional Regulatory T Cells Using Soluble RAGE Prevents Type 1 Diabetes

Type 1 diabetes (T1D) is an autoimmune disease with no cure. Therapeutic translation has been hampered by preclinical reproducibility. Here, short-term administration of an antagonist to the receptor for advanced glycation end products (sRAGE) protected against murine diabetes at two independent centers. Treatment with sRAGE increased regulatory T cells (Tregs) within islets, pancreatic lymph nodes and spleen, increasing islet insulin expression and function. Diabetes protection was abrogated by Treg depletion and shown to be dependent on antagonizing RAGE using knockout mice. Human Tregs treated with a RAGE ligand downregulated genes for suppression, migration and Treg homeostasis (FOXP3, IL7R, TIGIT, JAK1, STAT3, STAT5b, CCR4). Loss of suppressive function was reversed by sRAGE, where Tregs increased proliferation and suppressed conventional T cell division, confirming that sRAGE expands functional human Tregs. These results highlight sRAGE as an attractive treatment to prevent diabetes, showing efficacy at multiple research centers and in human T cells.

Dendritic cells and regulatory T cells expressing CCR4 provide resistance to coxsackievirus B5-induced pancreatitis

Type B coxsackieviruses (CVB) are enteroviruses responsible for a common infectious myocarditis and pancreatitis. DCs and regulatory T cells (Tregs) are key players in controlling virus replication and regulating the immune response and tissue damage, respectively. However, the mechanisms underlying cellular migration to target tissues remain unclear. In the present study, we found that CVB5 infection induced CCL17 production and controlled the migration of CCR4+ DCs and CCR4+ Tregs to the pancreatic lymph nodes (pLN). CVB5 infection of CCR4−/− mice reduced the migration of the CD8α+ DC subset and reduced DC activation and production of IFN-β and IL-12. Consequently, CCR4−/− mice presented decreased IFN-γ-producing CD4+ and CD8+ T cells, an increased viral load and more severe pancreatitis. In addition, CCR4−/− mice had impaired Treg accumulation in pLN as well as increased T lymphocyte activation. Adoptive transfer of CCR4+ Tregs but not CCR4− Tregs was able to regulate T lymphocyte activation upon CVB5 infection. The present data reveal a previously unknown role for CCR4 in coordinating immune cell migration to CVB-infected tissues and in controlling subsequent pancreatitis. These new insights may contribute to the design of future therapies for acute and chronic infection of non-polio enteroviruses.