Thioreductase-Containing Epitopes Inhibit the Development of Type 1 Diabetes in the NOD Mouse Model

Autoreactive CD4+ T cells recognizing islet-derived antigens play a primary role in type 1 diabetes. Specific suppression of such cells therefore represents a strategic target for the cure of the disease. We have developed a methodology by which CD4+ T cells acquire apoptosis-inducing properties on antigen-presenting cells after cognate recognition of natural sequence epitopes. We describe here that inclusion of a thiol-disulfide oxidoreductase (thioreductase) motif within the flanking residues of a single MHC class II-restricted GAD65 epitope induces GAD65-specific cytolytic CD4+ T cells (cCD4+ T). The latter, obtained either in vitro or by active immunization, acquire an effector memory phenotype and lyse APCs by a Fas–FasL interaction. Furthermore, cCD4+ T cells eliminate by apoptosis activated bystander CD4+ T cells recognizing alternative epitopes processed by the same APC. Active immunization with a GAD65 class II-restricted thioreductase-containing T cell epitope protects mice from diabetes and abrogates insulitis. Passive transfer of in vitro-elicited cCD4+ T cells establishes that such cells are efficient in suppressing autoimmunity. These findings provide strong evidence for a new vaccination strategy to prevent type 1 diabetes

Tocopherol Emulsions as Functional Autoantigen Delivery Vehicles Evoke Therapeutic Efficacy in Experimental Autoimmune Encephalomyelitis

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Molecular Pharmaceutics, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://doi.org/10.1021/acs.molpharmaceut.8b00887.Contemporary approaches to treating autoimmune diseases like multiple sclerosis broadly modulate the immune system and leave patients susceptible to severe adverse effects. Antigen-specific immunotherapies (ASIT) offer a unique opportunity to selectively suppress autoreactive cell populations but have suffered from marginal efficacy even when employing traditional adjuvants to improve delivery. The development of immunologically active antigen delivery vehicles could potentially increase the clinical success of antigen-specific immunotherapies. An emulsion of the antioxidant tocopherol delivering an epitope of proteolipid protein autoantigen (PLP139–151) yielded significant efficacy in mice with experimental autoimmune encephalomyelitis (EAE). In vitro studies indicated tocopherol emulsions reduced oxidative stress in antigen-presenting cells. Ex vivo analysis revealed that tocopherol emulsions shifted cytokine responses in EAE splenocytes. In addition, IgG responses against PLP139–151 were increased in mice treated with tocopherol emulsions delivering the antigen, suggesting a possible skew in immunity. Overall, tocopherol emulsions provide a functional delivery vehicle for ASIT capable of ameliorating autoimmunity in a murine model

Proton Sponge Trick for pH-Sensitive Disassembly of Polyethylenimine-Based siRNA Delivery Systems

Small interfering RNAs offer novel opportunities to inhibit gene expression in a highly selective and efficient manner but depend on cytosolic translocation with synthetic delivery systems. The polyethylenimine (PEI) is widely used for plasmid DNA transfection. However, the water-soluble PEI does not form siRNA polyplexes stable enough in extracellular media for effective delivery. We previously showed that rendering PEI insoluble in physiological media, without modifying drastically its overall cationic charge density, by simple conjugation with natural hydrophobic α-amino acids, can lead to effective siRNA delivery in mammalian cells. In here, we comprehensively investigated the mechanism behind the excellent efficacy of the leading PEIY vector. Our data revealed that the underlining proton sponge property is key to the effectiveness of the tyrosine−polyethylenimine conjugate as it may allow both endosomal rupture and siRNA liberation via an optimal pH-sensitive dissolution of the PEIY self-aggregates. Altogether, these results should facilitate the development of novel and more sophisticated siRNA delivery systems

Polydiacetylenic nanofibers as new siRNA vehicles for in vitro and in vivo delivery

Polydiacetylenic nanofibers (PDA-Nfs) obtained by photopolymerization of surfactant 1 were optimized for intracellular delivery of small interfering RNAs (siRNAs). PDA-Nfs/siRNA complexes efficiently silenced the oncogene Lim-1 in the renal cancer cells 786-O in vitro. Intraperitoneal injection of PDA-Nfs/siLim1 downregulated Lim-1 in subcutaneous tumor xenografts obtained with 786-O cells in nude mice. Thus, PDA-Nfs represent an innovative system for in vivo delivery of siRNAs

Inhibition of hepadnaviral replication by polyethylenimine-based intravenous delivery of antisense phosphodiester oligodeoxynucleotides to the liver

Antisense oligodeoxynucleotides (ODNs) appear as attractive anti-hepatitis B virus (HBV) agents. We investigated in vivo, in the duck HBV (DHBV) infection model, whether linear polyethylenimine (lPEI)-based intravenous delivery of the natural antisense phosphodiester ODNs (O-ODNs) can prevent their degradation and allow viral replication inhibition in the liver. DHBV-infected Pekin ducklings were injected with antisense O-ODNs covering the initiation codon of the DHBV large envelope protein, either in free form (O-ODN-AS2) or coupled to lPEI (lPEI/O-ODN-AS2). Following optimization of lPEI/O-ODN complex formulation, complete O-ODN condensation into a homogenous population of small (20–60 nm) spherical particles was achieved. Flow cytometry analysis showed that lPEI-mediated transfer allowed the intrahepatic delivery of lPEI/O-ODN-AS2 to increase three-fold as compared with the O-ODN-AS2. Following 9-day therapy the intrahepatic levels of both DHBV DNA and RNA were significantly decreased in the lPEI/O-ODN-AS2-treated group as compared with the O-ODN-AS2-treated, control lPEI/O-ODN-treated, and untreated controls. In addition, inhibition of intrahepatic viral replication by lPEI/O-ODN-AS2 was not associated with toxicity and was comparable with that induced by the phosphorothioate S-ODN-AS2 at a five-fold higher dose. Taken together, our results demonstrate that phosphodiester antisense lPEI/O-ODN complexes specifically inhibit hepadnaviral replication. Therefore we provide here the first in vivo evidence that intravenous treatment with antisense phosphodiester ODNs coupled to lPEI can selectively block a viral disease-causing gene in the liver

Fast All-Optical 10 Gb/s NRZ Wavelength Conversion and Power Limiting Function using Hybrid InP on SOI Nanocavity

International audienceA new optical switch is presented using InP/SOI hybrid photonic crystal nanocavity. Switching contrast of 11 dB with 20 mW peak power and recovery time of 14 ps are measured. NRZ wavelength conversion and power limiter are demonstrated at 10 Gb/s through system experiments with 6 and 1 mW peak power respectively

Photopolymerized micelles of diacetylene amphiphile: physical characterization and cell delivery properties:

A series of polydiacetylene (PDA) - based micelles were prepared from diacetylenic surfactant bearing polyethylene glycol, by increasing UV-irradiation times. These polymeric lipid micelles were analyzed by physicochemical methods, electron microscopy and NMR analysis. Cellular delivery of fluorescent dye suggests that adjusting the polymerization state is vital to reach the full in vitro potential of PDA-based delivery system

Bronchial artery embolization for management of massive cryptogenic hemoptysis: a case series

<p>Abstract</p> <p>Introduction</p> <p>Hemoptysis constitutes a common and urgent medical problem. Swift and effective management is of crucial importance, especially in severe, life-threatening cases. In cases of idiopathic hemoptysis, in which no underlying pulmonary pathology can be identified, treatment is challenging. We report our experience with bronchial artery embolization in the treatment of massive idiopathic hemoptysis.</p> <p>Cases presentation</p> <p>We report three consecutive cases of acute severe idiopathic hemoptysis. Our patients (two men aged 51 and 56 years and one woman aged 46 years), were of Caucasian ethnicity. We discuss the results and management of the patients, and review the literature. All three patients were treated safely and successfully with transcatheter embolization of the bronchial arteries using tris-acryl gelatin microspheres. Hemoptysis was controlled. All cases were followed up for 12 months, and there was no recurrence of bleeding.</p> <p>Conclusion</p> <p>Bronchial artery embolization is an effective tool for the evaluation and treatment of massive idiopathic hemoptysis.</p