Dendritic Cells Transduced to Express Interleukin 4 Reduce Diabetes Onset in Both Normoglycemic and Prediabetic Nonobese Diabetic Mice

Background: We and others have previously demonstrated that treatment with bone marrow derived DC genetically modified to express IL-4 reduce disease pathology in mouse models of collagen-induced arthritis and delayed-type hypersensitivity. Moreover, treatment of normoglycemic NOD mice with bone marrow derived DC, genetically modified to express interleukin 4 (IL-4), reduces the onset of hyperglycemia in a significant number of animals. However, the mechanism(s) through which DC expressing IL-4 function to prevent autoimmune diabetes and whether this treatment can reverse disease in pre-diabetic NOD mice are unknown. Methodology/Principal Findings: DC were generated from the bone marrow of NOD mice and transduced with adenoviral vectors encoding soluble murine IL-4 (DC/sIL-4), a membrane-bound IL-4 construct, or empty vector control. Female NOD mice were segregated into normoglycemic (<150mg/dL) and prediabetic groups (between 150 and 250 mg/dL) on the basis of blood glucose measurements, and randomized for adoptive transfer of 106 DC via a single i.v. injection. A single injection of DC/sIL-4, when administered to normoglycemic 12-week old NOD mice, significantly reduced the number of mice that developed diabetes. Furthermore, DC/sIL-4, but not control DC, decreased the number of mice progressing to diabetes when given to prediabetic NOD mice 12-16 weeks of age. DC/sIL-4 treatment also significantly reduced islet mononuclear infiltration and increased the expression of FoxP3 in the pancreatic lymph nodes of a subset of treated animals. Furthermore, DC/sIL-4 treatment altered the antigen-specific Th2:Th1 cytokine profiles as determined by ELISPOT of splenocytes in treated animals. Conclusions: Adoptive transfer of DC transduced to express IL-4 into both normoglycemic and prediabetic NOD mice is an effective treatment for T1D. © 2010 Ruffner, Robbins

Inhibition of Autoimmune Diabetes in NOD Mice by miRNA Therapy.

Autoimmune destruction of the pancreatic islets in Type 1 diabetes is mediated by both increased proinflammatory (Teff) and decreased regulatory (Treg) T lymphocytes resulting in a significant decrease in the Treg:Teff ratio. The non-obese diabetic (NOD) mouse is an excellent in vivo model for testing potential therapeutics for attenuating the decrease in the Treg:Teff ratio and inhibiting disease pathogenesis. Here we show for the first time that a bioreactor manufactured therapeutic consisting of a complex of miRNA species (denoted as TA1) can effectively reset the NOD immune system from a proinflammatory to a tolerogenic state thus preventing or delaying autoimmune diabetes. Treatment of NOD mice with TA1 resulted in a systemic broad-spectrum upregulation of tolerogenic T cell subsets with a parallel downregulation of Teff subsets yielding a dramatic increase in the Treg:Teff ratio. Moreover, the murine-derived TA1 was highly effective in the inhibition of allorecognition of HLA-disparate human PBMC. TA1 demonstrated dose-responsiveness and exhibited equivalent or better inhibition of allorecognition driven proliferation than etanercept (a soluble TNF receptor). These findings demonstrate that miRNA-based therapeutics can effectively attenuate or arrest autoimmune disease processes and may be of significant utility in a broad range of autoimmune diseases including Type 1 diabetes

Exploiting the Role of Endogenous Lymphoid-Resident Dendritic Cells in the Priming of NKT Cells and CD8+ T Cells to Dendritic Cell-Based Vaccines

Transfer of antigen between antigen-presenting cells (APCs) is potentially a physiologically relevant mechanism to spread antigen to cells with specialized stimulatory functions. Here we show that specific CD8+ T cell responses induced in response to intravenous administration of antigen-loaded bone marrow-derived dendritic cells (BM-DCs), were ablated in mice selectively depleted of endogenous lymphoid-resident langerin+ CD8α+ dendritic cells (DCs), suggesting that the antigen is transferred from the injected cells to resident APCs. In contrast, antigen-specific CD4+ T cells were primed predominantly by the injected BM-DCs, with only very weak contribution of resident APCs. Crucially, resident langerin+ CD8α+ DCs only contributed to the priming of CD8+ T cells in the presence of maturation stimuli such as intravenous injection of TLR ligands, or by loading the BM-DCs with the glycolipid α-galactosylceramide (α-GalCer) to recruit the adjuvant activity of activated invariant natural killer-like T (iNKT) cells. In fact, injection of α-GalCer-loaded CD1d−/− BM-DCs resulted in potent iNKT cell activation, suggesting that this glycolipid antigen can also be transferred to resident CD1d+ APCs. While iNKT cell activation per se was independent of langerin+ CD8α+ DCs, some iNKT cell-mediated activities were reduced, notably release of IL-12p70 and transactivation of NK cells. We conclude that both protein and glycolipid antigens can be exchanged between distinct DC species. These data suggest that the efficacy of DC-based vaccination strategies may be improved by the incorporation of a systemic maturation signal aimed to engage resident APCs in CD8+ T cell priming, and α-GalCer may be particularly well suited to this purpose

A Cytosine Methyltransferase Homologue Is Essential for Sexual Development in Aspergillus nidulans

Background: The genome defense processes RIP (repeat-induced point mutation) in the filamentous fungus Neurospora crassa, and MIP (methylation induced premeiotically) in the fungus Ascobolus immersus depend on proteins with DNA methyltransferase (DMT) domains. Nevertheless, these proteins, RID and Masc1, respectively, have not been demonstrated to have DMT activity. We discovered a close homologue in Aspergillus nidulans, a fungus thought to have no methylation and no genome defense system comparable to RIP or MIP. Principal Findings: We report the cloning and characterization of the DNA methyltransferase homologue A (dmtA) gene from Aspergillus nidulans. We found that the dmtA locus encodes both a sense (dmtA) and an anti-sense transcript (tmdA). Both transcripts are expressed in vegetative, conidial and sexual tissues. We determined that dmtA, but not tmdA, is required for early sexual development and formation of viable ascospores. We also tested if DNA methylation accumulated in any of the dmtA/tmdA mutants we constructed, and found that in both asexual and sexual tissues, these mutants, just like wild-type strains, appear devoid of DNA methylation. Conclusions/Significance: Our results demonstrate that a DMT homologue closely related to proteins implicated in RIP and MIP has an essential developmental function in a fungus that appears to lack both DNA methylation and RIP or MIP. It remains formally possible that DmtA is a bona fide DMT, responsible for trace, undetected DNA methylation that i

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta