Regulatory T cells hold promise as targets for therapeutic intervention in autoimmunity, but approaches capable of expanding antigen-specific regulatory T cells in vivo are currently not available. Here we show that systemic delivery of nanoparticles coated with autoimmune-disease-relevant peptides bound to major histocompatibility complex class II (pMHCII) molecules triggers the generation and expansion of antigen-specific regulatory CD4(+) T cell type 1 (TR1)-like cells in different mouse models, including mice humanized with lymphocytes from patients, leading to resolution of established autoimmune phenomena. Ten pMHCII-based nanomedicines show similar biological effects, regardless of genetic background, prevalence of the cognate T-cell population or MHC restriction. These nanomedicines promote the differentiation of disease-primed autoreactive T cells into TR1-like cells, which in turn suppress autoantigen-loaded antigen-presenting cells and drive the differentiation of cognate B cells into disease-suppressing regulatory B cells, without compromising systemic immunity. pMHCII-based nanomedicines thus represent a new class of drugs, potentially useful for treating a broad spectrum of autoimmune conditions in a disease-specific manner.
Background Minor hallucinations and well‐structured hallucinations are considered in the severity continuum of the psychotic spectrum associated with Parkinson's disease. Although their chronological relationship is largely unknown, the spatial patterns of brain atrophy in these 2 forms of hallucinations partially overlap, suggesting they share similar pathophysiological processes. Functional connectivity studies show that disruption of functional networks involved in perception and attention could be relevant in the emergence of well‐structured hallucinations. However, functional neuroimaging studies in patients with isolated minor hallucinations are lacking. The objectives of this study were to explore the structural and functional changes underlying minor hallucinations. Methods We compared patients with (n = 18) and without (n = 14) minor hallucinations using a multimodal structural (gray‐matter volume voxel‐based morphometry) and functional (seed‐to‐whole‐brain resting‐state functional MRI) neuroimaging study. Results Coincident with previously described structural changes in well‐structured hallucinations in Parkinson's disease, patients with minor hallucinations exhibited gray‐matter atrophy with significant voxel‐wise differences in visuoperceptual processing areas and core regions of the default mode network. Functional connectivity changes consisted of altered connectivity within the default mode network, reduced negative correlation with task‐positive network, and aberrant connectivity between posterior regions of the default mode network and visual‐processing areas. These changes are in accordance with the attentional networks hypothesis proposed for well‐structured hallucinations. Conclusions Although longitudinal studies are needed to assess the potential role of minor hallucinations as an early clinical biomarker of progression to well‐structured hallucinations, the present findings show that the 2 phenomena share similar structural and functional brain correlates. © 2018 International Parkinson and Movement Disorder Society
LC is a misdiagnosed entity associated with considerable diagnostic delay. MRI evidence of bilateral hemispheric involvement and CSF pleocytosis should be alerts for this diagnosis. Treatment with methotrexate-based chemotherapy must be considered, especially for patients with good KPS.
IntroductionThe development of new therapies to induce self-tolerance has been an important medical health challenge in type 1 diabetes. An ideal immunotherapy should inhibit the autoimmune attack, avoid systemic side effects and allow β-cell regeneration. Based on the immunomodulatory effects of apoptosis, we hypothesized that apoptotic mimicry can help to restore tolerance lost in autoimmune diabetes.ObjectiveTo generate a synthetic antigen-specific immunotherapy based on apoptosis features to specifically reestablish tolerance to β-cells in type 1 diabetes.MethodsA central event on the surface of apoptotic cells is the exposure of phosphatidylserine, which provides the main signal for efferocytosis. Therefore, phosphatidylserine-liposomes loaded with insulin peptides were generated to simulate apoptotic cells recognition by antigen presenting cells. The effect of antigen-specific phosphatidylserine-liposomes in the reestablishment of peripheral tolerance was assessed in NOD mice, the spontaneous model of autoimmune diabetes. MHC class II-peptide tetramers were used to analyze the T cell specific response after treatment with phosphatidylserine-liposomes loaded with peptides.ResultsWe have shown that phosphatidylserine-liposomes loaded with insulin peptides induce tolerogenic dendritic cells and impair autoreactive T cell proliferation. When administered to NOD mice, liposome signal was detected in the pancreas and draining lymph nodes. This immunotherapy arrests the autoimmune aggression, reduces the severity of insulitis and prevents type 1 diabetes by apoptotic mimicry. MHC class II tetramer analysis showed that peptide-loaded phosphatidylserine-liposomes expand antigen-specific CD4+ T cells in vivo. The administration of phosphatidylserine-free liposomes emphasizes the importance of phosphatidylserine in the modulation of antigen-specific CD4+ T cell expansion.ConclusionsWe conclude that this innovative immunotherapy based on the use of liposomes constitutes a promising strategy for autoimmune diseases.
Background Diffuse hemispheric gliomas, H3 G34-mutant (DHG H3G34-mutant) constitute a distinct type of aggressive brain tumors. Although initially described in children, they can also affect adults. The aims were to describe the characteristics of DHG H3G34-mutant in adults and to compare them to those of established types of adult WHO grade IV gliomas. Methods The characteristics of 17 adult DHG H3G34-mutant, 32 H3.3 K27M-mutant diffuse midline gliomas (DMG), 100 IDH-wildtype and 36 IDH-mutant glioblastomas were retrospectively analyzed. Results Median age at diagnosis in adult DHG H3G34-mutant was 25 years (range: 19-33). All tumors were hemispheric. For 9 patients (56%), absent or faint contrast enhancement initially suggested another diagnosis than a high-grade glioma, and diffusion-weighted imaging seemed retrospectively more helpful to suspect an aggressive tumor than MR-spectroscopy and perfusion MRI. All cases were IDH-wildtype. Most cases were immunonegative for ATRX (93%) and Olig2 (100%) and exhibited MGMT promoter methylation (82%). The clinical and radiological presentations of adult DHG H3G34-mutant were different from those of established types of adult grade IV gliomas. Median overall survival of adult DHG H3G34-mutant was 12.4 months compared to 19.6 months (p=.56), 11.7 months (p=.45) and 50.5 months (p=0.006) in H3.3 K27M-mutant DMG, IDH-wildtype and IDH-mutant glioblastomas, respectively. Conclusions Adult DHG H3G34-mutant are associated with distinct characteristics compared to those of established types of adult WHO grade IV gliomas. The present study supports considering these tumors as a new type of WHO grade IV glioma in future classifications.
Glutamic acid decarboxylase (GAD) is an intracellular enzyme whose physiologic function is the decarboxylation of glutamate to gamma-aminobutyric acid (GABA), the main inhibitory neurotransmitter within the central nervous system. GAD antibodies (Ab) have been associated with multiple neurological syndromes, including stiff-person syndrome, cerebellar ataxia, and limbic encephalitis, which are all considered to result from reduced GABAergic transmission. The pathogenic role of GAD Ab is still debated, and some evidence suggests that GAD autoimmunity might primarily be cell-mediated. Diagnosis relies on the detection of high titers of GAD Ab in serum and/or in the detection of GAD Ab in the cerebrospinal fluid. Due to the relative rarity of these syndromes, treatment schemes and predictors of response are poorly defined, highlighting the unmet need for multicentric prospective trials in this population. Here, we reviewed the main clinical characteristics of neurological syndromes associated with GAD Ab, focusing on pathophysiologic mechanisms.
This prospective study sought to identify the potential reversibility of oxaliplatin-induced peripheral neuropathy (OXAIPN) by following-up its long-term course 2 years after discontinuation of oxaliplatin (OXA)-based chemotherapy. Participants were 91 colorectal cancer patients treated with OXA-based chemotherapy. Neurological assessment, clinical Total Neuropathy Score© (TNSc©) and nerve conduction studies were performed at baseline (T0), the end of chemotherapy (T1) and 2 years (T2) after discontinuation of chemotherapy. A total of 73 of 91 (80%) patients experienced OXAIPN at T1. At a median follow-up of 25 months, persistence of chronic OXAIPN was present in 61 of 73 patients (84%) and complete resolution was present in 12 patients (17%). Longitudinal comparison of TNSc© values between T1 and T2 revealed that the overall severity of OXAIPN in those 61 patients significantly decreased over time. Median TNSc© values were nine (range: 2-15) at T1 vs. four (range: 2-12) at T2 (P < 0.001). Likewise, sensory nerve conduction measures at T2 significantly improved in all sensory nerves tested, compared with T1. Severity of OXAIPN at T2 was significantly associated (P < 0.001) with high severity of OXAIPN at T1. In conclusion, persistence of OXAIPN beyond 2 years after finishing chemotherapy is common. Clinical and neurophysiological improvement is observed, although recovery is often incomplete.
Pungent chemical compounds originating from decaying tissue are strong drivers of animal behavior. Two of the best-characterized death smell components are putrescine (PUT) and cadaverine (CAD), foul-smelling molecules produced by decarboxylation of amino acids during decomposition. These volatile polyamines act as ‘necromones’, triggering avoidance or attractive responses, which are fundamental for the survival of a wide range of species. The few studies that have attempted to identify the cognate receptors for these molecules have suggested the involvement of the seven-helix trace amine-associated receptors (TAARs), localized in the olfactory epithelium. However, very little is known about the precise chemosensory receptors that sense these compounds in the majority of organisms and the molecular basis of their interactions. In this work, we have used computational strategies to characterize the binding between PUT and CAD with the TAAR6 and TAAR8 human receptors. Sequence analysis, homology modeling, docking and molecular dynamics studies suggest a tandem of negatively charged aspartates in the binding pocket of these receptors which are likely to be involved in the recognition of these small biogenic diamines.
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