1,25-Dihydroxyvitamin D-3 and its analog TX527 promote a stable regulatory T cell phenotype in T cells from type 1 diabetes patients

The emergence of regulatory T cells (Tregs) as central mediators of peripheral tolerance in the immune system has led to an important area of clinical investigation to target these cells for the treatment of autoimmune diseases such as type 1 diabetes. We have demonstrated earlier that in vitro treatment of T cells from healthy individuals with TX527, a low-calcemic analog of bioactive vitamin D, can promote a CD4(+)CD25(high)CD127(low) regulatory profile and imprint a migratory signature specific for homing to sites of inflammation. Towards clinical application of vitamin D-induced Tregs in autologous adoptive immunotherapy for type 1 diabetes, we show here that 1,25-dihydroxyvitamin D-3 [1,25(OH)(2)D-3] and TX527 similarly imprint T cells from type 1 diabetes patients with a CD4(+)CD25(high)CD127(low) regulatory profile, modulate surface expression of skin- and inflammation-homing receptors, and increase expression of CTLA-4 and OX-40. Also, 1,25(OH)(2)D-3 and TX527 treatment inhibit the production of effector cytokines IFN-gamma, IL-9, and IL-17. Importantly, 1,25(OH)(2)D-3 and TX527 promote the induction of IL-10-producing CD4(+)CD25(high)CD127(low) T cells with a stable phenotype and the functional capacity to suppress proliferation of autologous responder T cells in vitro. These findings warrant additional validation of vitamin D-induced Tregs in view of future autologous adoptive immunotherapy in type 1 diabetes

Ubiquitin D regulates IRE1 α/c-Jun N-terminal kinase (JNK) protein-dependent apoptosis in pancreatic beta cells

Pro-inflammatory cytokines contribute to pancreatic beta cell apoptosis in type 1 diabetes at least in part by inducing endoplasmic reticulum (ER) stress and the consequent unfolded protein response (UPR). It remains to be determined what causes the transition from "physiological" to "apoptotic" UPR, but accumulating evidence indicates that signaling by the ER transmembrane protein IRE1 alpha is critical for this transition. IRE1 alpha activation is regulated by both intra-ER and cytosolic cues. We evaluated the role for the presently discovered cytokine-induced and IRE1 alpha-interacting protein ubiquitin D (UBD) on the regulation of IRE1 alpha and its downstream targets. UBD was identified by use of a MAPPIT (mammalian protein-protein interaction trap)-based IRE1 alpha interactome screen followed by comparison against functional genomic analysis of human and rodent beta cells exposed to pro-inflammatory cytokines. Knockdown ofUBDin human and rodent beta cells and detailed signal transduction studies indicated that UBD modulates cytokine-induced UPR/IRE1 alpha activation and apoptosis. UBD expression is induced by the pro-inflammatory cytokines interleukin (IL)-1 beta and interferon (IFN)-gamma in rat and human pancreatic beta cells, and it is also up-regulated in beta cells of inflamed islets from non-obese diabetic mice. UBD interacts with IRE1 alpha in human and rodent beta cells, modulating IRE1 alpha-dependent activation of JNK and cytokine-induced apoptosis. Our data suggest that UBD provides a negative feedback on cytokine-induced activation of the IRE1 alpha/JNK pro-apoptotic pathway in cytokine-exposed beta cells

Human multipotent adult progenitor cells enhance islet function and revascularisation when co-transplanted as a composite pellet in a mouse model of diabetes

AIMS/HYPOTHESIS: Hypoxia in the initial days after islet transplantation leads to considerable loss of islet mass and contributes to disappointing outcomes in the clinical setting. The aim of the present study was to investigate whether co-transplantation of human non-endothelial bone marrow-derived multipotent adult progenitor cells (MAPCs), which are non-immunogenic and can secrete angiogenic growth factors during the initial days after implantation, could improve islet engraftment and survival.METHODS: Islets (150) were co-transplanted, with or without human MAPCs (2.5 × 105) as separate or composite pellets, under the kidney capsule of syngeneic alloxan-induced diabetic C57BL/6 mice. Blood glucose levels were frequently monitored and IPGTTs were carried out. Grafts and serum were harvested at 2 and 5 weeks after transplantation to assess outcome.RESULTS: Human MAPCs produced high amounts of angiogenic growth factors, including vascular endothelial growth factor, in vitro and in vivo, as demonstrated by the induction of neo-angiogenesis in the chorioallantoic membrane assay. Islet-human MAPC co-transplantation as a composite pellet significantly improved the outcome of islet transplantation as measured by the initial glycaemic control, diabetes reversal rate, glucose tolerance and serum C-peptide concentration compared with the outcome following transplantation of islets alone. Histologically, a higher blood vessel area and density in addition to a higher vessel/islet ratio were detected in recipients of islet-human MAPC composites.CONCLUSIONS/INTERPRETATION: The present data suggest that co-transplantation of mouse pancreatic islets with human MAPCs, which secrete high amounts of angiogenic growth factors, enhance islet graft revascularisation and subsequently improve islet graft function

Footprint of pancreas infiltrating and circulating immune cells throughout type 1 diabetes development

IntroductionType 1 diabetes (T1D) is defined by immune cell infiltration of the pancreas, in particular the islets of Langerhans, referred to as insulitis, which is especially prominent during the early disease stages in association with decreased beta cell mass. An in-depth understanding of the dynamics and phenotype of the immune cells infiltrating the pancreas and the accompanying changes in their profiles in peripheral blood during T1D development is critical to generate novel preventive and therapeutic approaches, as well as to find biomarkers for the disease process.MethodsUsing multi-parameter flow cytometry, we explored the dynamic changes of immune cells infiltrating the pancreas and the pancreatic draining lymph nodes (PLN), compared to those in peripheral blood in female and male non-obese diabetic (NOD) mice during T1D progression.ResultsThe early stages of T1D development were characterized by an influx of innate dendritic cells and neutrophils in the pancreas. While dendritic cells seemed to move in and out (to the PLN), neutrophils accumulated during the pre-symptomatic phase and reached a maximum at 8 weeks of age, after which their numbers declined. During disease progression, CD4+ and CD8+ T cells appeared to continuously migrate from the PLN to the pancreas, which coincided with an increase in beta cell autoimmunity and insulitis severity, and a decline in insulin content. At 12 weeks of age, CD4+ and especially CD8+ T cells in the pancreas showed a dramatic shift from naïve to effector memory phenotype, in contrast to the PLN, where most of these cells remained naïve. A large proportion of pancreas infiltrating CD4+ T cells were naïve, indicating that antigenic stimulation was not necessary to traffic and invade the pancreas. Interestingly, a pre-effector-like T cell dominated the peripheral blood. These cells were intermediates between naïve and effector memory cells as identified by single cell RNA sequencing and might be a potential novel therapeutic target.ConclusionThese time- and tissue-dependent changes in the dynamics and functional states of CD4+ and CD8+ T cells are essential steps in our understanding of the disease process in NOD mice and need to be considered for the interpretation and design of disease-modifying therapies

dietary supplementation with high doses of regular vitamin d3 safely reduces diabetes incidence in nod mice when given early and long term

High doses of the active form of vitamin D3, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) prevent diabetes in the non-obese diabetic (NOD) mouse but also elicit unwanted calcemic side-effects. Because immune cells themselves can convert vitamin D3 into 1,25(OH)2D3 locally, we hypothesized that dietary vitamin D3 can also prevent disease. Thus, we evaluated whether dietary administration of high doses of regular vitamin D3 (800 IU per day) during different periods of life (pregnancy and lactation, early-life (3-14 weeks of age), or lifelong (3-35 weeks of age)) safely prevents diabetes in NOD mice. We found that only lifelong treatment raised serum 25-hydroxyvitamin D3 from 173 nmol/L in controls to 290 nmol/L, without inducing signs of calcemic or bone toxicity, and significantly reduced diabetes development in both male and female NOD mice. This diabetes protection by vitamin D3 correlated with preserved pancreatic insulin content and improved insulitis scores. Moreover, vitamin D3 treatment decreased interferon-γ-positive CD8+ T-cells and increased CD4+(CD25+)FoxP3+ T-cells in pancreatic draining lymph nodes. In conclusion, this study shows for the first time that high doses of regular dietary vitamin D3 can safely prevent diabetes in NOD mice when administered lifelong, although caution is warranted with regards to administering equivalently high doses in humans

The active enhancer network operated by liganded RXR supports angiogenic activity in macrophages

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Longitudinal in vivo assessment of host-microbe interactions in a murine model of pulmonary aspergillosis

The fungus Aspergillus fumigatus is ubiquitous in nature and the most common cause of invasive pulmonary aspergillosis (IPA) in patients with a compromised immune system. The development of IPA in patients under immunosuppressive treatment or in patients with primary immunodeficiency demonstrates the importance of the host immune response in controlling aspergillosis. However, study of the host-microbe interaction has been hampered by the lack of tools for their non-invasive assessment. We developed a methodology to study the response of the host's immune system against IPA longitudinally in vivo by using fluorine-19 magnetic resonance imaging (F-19 MRI). We showed the advantage of a perfluorocarbon-based contrast agent for the in vivo labeling of macrophages and dendritic cells, permitting quantification of pulmonary inflammation in different murine IPA models. Our findings reveal the potential of F-19 MRI for the assessment of rapid kinetics of innate immune response against IPA and the permissive niche generated through immunosuppression

Generation of hepatocyte- and endocrine pancreatic-like cells from human induced endodermal progenitor cells

Multipotent Adult Progenitor Cells (MAPCs) are one potential stem cell source to generate functional hepatocytes or β-cells. However, human MAPCs have less plasticity than pluripotent stem cells (PSCs), as their ability to generate endodermal cells is not robust. Here we studied the role of 14 transcription factors (TFs) in reprogramming MAPCs to induced endodermal progenitor cells (iENDO cells), defined as cells that can be long-term expanded and differentiated to both hepatocyte- and endocrine pancreatic-like cells. We demonstrated that 14 TF-iENDO cells can be expanded for at least 20 passages, differentiate spontaneously to hepatocyte-, endocrine pancreatic-, gut tube-like cells as well as endodermal tumor formation when grafted in immunodeficient mice. Furthermore, iENDO cells can be differentiated in vitro into hepatocyte- and endocrine pancreatic-like cells. However, the pluripotency TF OCT4, which is not silenced in iENDO cells, may contribute to the incomplete differentiation to mature cells in vitro and to endodermal tumor formation in vivo. Nevertheless, the studies presented here provide evidence that reprogramming of adult stem cells to an endodermal intermediate progenitor, which can be expanded and differentiate to multiple endodermal cell types, might be a valid alternative for the use of PSCs for creation of endodermal cell types

Increased β-Cell Mass by Islet Transplantation and PLAG1 Overexpression Causes Hyperinsulinemic Normoglycemia and Hepatic Insulin Resistance in Mice

OBJECTIVE-It is believed that an organism remains normoglycemic despite an increase in the beta-cell mass because of decreased insulin production by beta-cells on a per-cell basis However, some transgenic mouse models with beta-cell hyperplasia suggest that insulin production remains excessive and that normoglycemia is maintained by insulin resistance METHODS-Here, we investigated the effect of an increased beta-cell mass on glycemia and insulin resistance by grafting excess normal islets in normoglycemic mice, as well as using targeted PLAG1 expression in beta-cells, which leads to beta-cell expansion. RESULTS-In both models, fasting plasma insulin levels were increased, even though animals were normoglycemic. After an intraperitoneal glucose tolerance test, plasma insulin levels increased, which was associated with improved glucose clearing Under these conditions, normoglycemia is maintained by hepatic insulin resistance as demonstrated by hyperinsulinemic euglycemic clamp experiments. CONCLUSIONS-In conclusion, we demonstrate that when excess beta-cells are grafted, insulin production on a per beta-cell basis is not sufficiently decreased, leading to hyperinsulinemia and hepatic insulin resistance. This observation might be important for the design of stem cell-based islet replacement therapies. Diabetes 59:1957-1965, 2010Diabetes mellitus: pathophysiological changes and therap

Inhibition of histone deacetylase 6 (HDAC6) protects against vincristine-induced peripheral neuropathies and inhibits tumor growth

As cancer is becoming more and more a chronic disease, a large proportion of patients is confronted with devastating side effects of certain anti-cancer drugs. The most common neurological complications are painful peripheral neuropathies. Chemotherapeutics that interfere with microtubules, including plant-derived vinca-alkaloids such as vincristine, can cause these chemotherapy-induced peripheral neuropathies (CIPN). Available treatments focus on symptom alleviation and pain reduction rather than prevention of the neuropathy. The aim of this study was to investigate the potential of specific histone deacetylase 6 (HDAC6) inhibitors as a preventive therapy for CIPN using multiple rodent models for vincristine-induced peripheral neuropathies (VIPN). HDAC6 inhibition increased the level of acetylated α-tubulin in tissues of rodents undergoing vincristine-based chemotherapy, which correlates to a reduced severity of the neurological symptoms, both at the electrophysiological and the behavioral level. Mechanistically, disturbances in axonal transport of mitochondria is considered as an important contributing factor in the pathophysiology of VIPN. As vincristine interferes with the polymerization of microtubules, we investigated whether disturbances in axonal transport could contribute to VIPN. We observed that increasing α-tubulin acetylation through HDAC6 inhibition restores vincristine-induced defects of axonal transport in cultured dorsal root ganglion neurons. Finally, we assured that HDAC6-inhibition offers neuroprotection without interfering with the anti-cancer efficacy of vincristine using a mouse model for acute lymphoblastic leukemia. Taken together, our results emphasize the therapeutic potential of HDAC6 inhibitors with beneficial effects both on vincristine-induced neurotoxicity, as well as on tumor proliferation. ispartof: Neurobiology of Disease vol:111 pages:59-69 ispartof: location:United States status: publishe