T-follicular helper cells are epigenetically poised to transdifferentiate into T-regulatory type 1 cells.

Chronic antigenic stimulation can trigger the formation of interleukin 10 (IL-10)-producing T-regulatory type 1 (TR1) cells in vivo. We have recently shown that murine T-follicular helper (TFH) cells are precursors of TR1 cells and that the TFH-to-TR1 cell transdifferentiation process is characterized by the progressive loss and acquisition of opposing transcription factor gene expression programs that evolve through at least one transitional cell stage. Here, we use a broad range of bulk and single-cell transcriptional and epigenetic tools to investigate the epigenetic underpinnings of this process.

Transcriptional re-programming of insulin B-chain epitope-specific T-follicular helper cells into anti-diabetogenic T-regulatory type-1 cells.

Systemic delivery of nanoparticles (NPs) coated with mono-specific autoimmune disease-relevant peptide-major histocompatibility complex class II (pMHCII) molecules can resolve organ inflammation in various disease models in a disease-specific manner without impairing normal immunity. These compounds invariably trigger the formation and systemic expansion of cognate pMHCII-specific T-regulatory type 1 (TR1) cells. By focusing on type 1 diabetes (T1D)-relevant pMHCII-NP types that display an epitope from the insulin B-chain bound to the same MHCII molecule (IA) on three different registers, we show that pMHCII-NP-induced TR1 cells invariably co-exist with cognate T-Follicular Helper (TFH)-like cells of quasi-identical clonotypic composition and are oligoclonal, yet transcriptionally homogeneous.

A T follicular helper cell origin for T regulatory type 1 cells.

Chronic antigenic stimulation can trigger the differentiation of antigen-experienced CD4 T cells into T regulatory type 1 (TR1) cells, a subset of interleukin-10-producing Treg cells that do not express FOXP3. The identities of the progenitor(s) and transcriptional regulators of this T-cell subset remain unclear. Here, we show that the peptide-major histocompatibility complex class II (pMHCII) monospecific immunoregulatory T-cell pools that arise in vivo in different genetic backgrounds in response to pMHCII-coated nanoparticles (pMHCII-NPs) are invariably comprised of oligoclonal subpools of T follicular helper (TFH) and TR1 cells with a nearly identical clonotypic composition but different functional properties and transcription factor expression profiles.

Extremely short bioavailability and fast pharmacodynamic effects of pMHC-based nanomedicines.

Nanoparticles (NPs) coated with autoimmune disease-relevant peptide-major histocompatibility complexes (pMHCs) can blunt autoimmune diseases by re-programming cognate effector T-lymphocytes into disease-suppressing regulatory T-cells, followed by massive expansion. Here, a method to quantify the absolute amounts of the active drug product is developed, to understand the relationship between bioavailability and pharmacodynamics. Incubation with plasma results in the formation of a protein corona that stabilizes the directional pMHC coat, shielding it from proteolysis or anti-drug antibody recognition, without any appreciable loss in biological potency.

Increased yields and biological potency of knob-into-hole-based soluble MHC class II molecules.

Assembly of soluble peptide-major histocompatibility complex class II (pMHCII) monomers into multimeric structures enables the detection of antigen-specific CD4 T cells in biological samples and, in some configurations, their reprogramming in vivo. Unfortunately, current MHCII-αβ chain heterodimerization strategies are typically associated with low production yields and require the use of foreign affinity tags for purification, precluding therapeutic applications in humans. Here, we show that fusion of peptide-tethered or empty MHCII-αβ chains to the IgG1-Fc mutated to form knob-into-hole structures results in the assembly of highly stable pMHCII monomers.

Peptide-MHC-based nanomedicines for autoimmunity function as T-cell receptor microclustering devices.

We have shown that nanoparticles (NPs) can be used as ligand-multimerization platforms to activate specific cellular receptors in vivo. Nanoparticles coated with autoimmune disease-relevant peptide-major histocompatibility complexes (pMHC) blunted autoimmune responses by triggering the differentiation and expansion of antigen-specific regulatory T cells in vivo. Here, we define the engineering principles impacting biological activity, detail a synthesis process yielding safe and stable compounds, and visualize how these nanomedicines interact with cognate T cells.

Glutamatergic stimulation induces GluN2B translation by the nitric oxide-Heme-Regulated eIF2α kinase in cortical neurons.

The activation of N-Methyl D-Aspartate Receptor (NMDAR) by glutamate is crucial in the nervous system function, particularly in memory and learning. NMDAR is composed by two GluN1 and two GluN2 subunits. GluN2B has been reported to participate in the prevalent NMDAR subtype at synapses, the GluN1/2A/2B.

Expanding antigen-specific regulatory networks to treat autoimmunity.

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.

Physiological Control of Nitric Oxide in Neuronal BACE1 Translation by Heme-Regulated eIF2α Kinase HRI Induces Synaptogenesis.

Aims: Hippocampus is the brain center for memory formation, a process that requires synaptogenesis. However, hippocampus is dramatically compromised in Alzheimer's disease due to the accumulation of amyloid β-peptide, whose production is initiated by β-site APP Cleaving Enzyme 1 (BACE1). It is known that pathological stressors activate BACE1 translation through the phosphorylation of the eukaryotic initiation factor-2α (eIF2α) by GCN2, PERK, or PKR kinases, leading to amyloidogenesis.

A monoclonal antibody against the extracellular domain of mouse and human epithelial V-like antigen 1 reveals a restricted expression pattern among CD4- CD8- thymocytes.

Expression of transcripts for the homotypic adhesion protein epithelial V-like antigen 1 (EVA1), also known as myelin protein zero like-2 (Mpzl2), is known to be present in thymic stromal cells. However, protein expression within different thymic subsets, stromal and/or lymphoid, has not been characterized due a lack of specific reagents. To address this, we generated a hybridoma (G9P3-1) secreting a monoclonal antibody (G9P3-1Mab), reactive against both human and mouse EVA1.

Activation of PKR causes amyloid ß-peptide accumulation via de-repression of BACE1 expression.

BACE1 is a key enzyme involved in the production of amyloid ß-peptide (Aß) in Alzheimer's disease (AD) brains. Normally, its expression is constitutively inhibited due to the presence of the 5'untranslated region (5'UTR) in the BACE1 promoter. BACE1 expression is activated by phosphorylation of the eukaryotic initiation factor (eIF)2-alpha, which reverses the inhibitory effect exerted by BACE1 5'UTR.

A gain-of-function SNP in TRPC4 cation channel protects against myocardial infarction.

Aims: The TRPC4 non-selective cation channel is widely expressed in the endothelium, where it generates Ca(2+) signals that participate in the endothelium-mediated vasodilatory response. This study sought to identify single-nucleotide polymorphisms (SNPs) in the TRPC4 gene that are associated with myocardial infarction (MI).

Methods And Results: Our candidate-gene association studies identified a missense SNP (TRPC4-I957V) associated with a reduced risk of MI in diabetic patients [odds ratio (OR) = 0.

Loss of function of transient receptor potential vanilloid 1 (TRPV1) genetic variant is associated with lower risk of active childhood asthma.

Transient receptor potential cation channels of the vanilloid subfamily (TRPV) participate in the generation of Ca(2+) signals at different locations of the respiratory system, thereby controlling its correct functioning. TRPV1 expression and activity appear to be altered under pathophysiological conditions such as chronic cough and airway hypersensitivity, whereas TRPV4 single nucleotide polymorphisms (SNP) are associated with chronic obstructive pulmonary disease. However, to date, there is no information about the genetic impact of either TRPV1 or TRPV4 on asthma pathophysiology.

The asthma-associated ORMDL3 gene product regulates endoplasmic reticulum-mediated calcium signaling and cellular stress.

Alterations of protein folding or Ca(2+) levels within the endoplasmic reticulum (ER) result in the unfolded-protein response (UPR), a process considered as an endogenous inducer of inflammation. Thereby, understanding how genetic factors modify UPR is particularly relevant in chronic inflammatory diseases such as asthma. Here we identified that ORMDL3, the only genetic risk factor recently associated to asthma in a genome wide study, alters ER-mediated Ca(2+) homeostasis and facilitates the UPR.

The progesterone receptor regulates the expression of TRPV4 channel.

The transient receptor potential cationic channel TRPV4 contributes to different aspects of cell physiology via the generation of a Ca2+ signal and/or depolarization of the membrane potential. TRPV4 channel integrates distinct physical and chemical stimuli, including osmotic and mechanical stress, heat, acidic pH, endogenous ligands, and synthetic agonists such as 4alpha-phorbol 12,13-didecanoate (4alphaPDD). Although several regulatory sites controlling TRPV4 channel activity have been identified, very little is known about the regulation of TRPV4 expression, a situation common to other TRP channels.

A novel muscle DNA-binding activity in the GLUT1 promoter.

GLUT1 glucose transporters are highly expressed in proliferating and transformed cells and serum and cAMP or the transcription factor Sp1 induce GLUT1 gene transcription. Here we identified a cis element situated at -46/-37 (MG1E - muscle-specific GLUT1 element) to which muscle-specific nuclear factors bind, and the DNA-protein complexes showed electrophoretic mobility of 41 and 32 kDa. MyoD over-expression induced the generation of MG1E-protein complexes characteristic of myoblast cells.

The use of immobilized yeast technology for the production of rose and white sparkling wine from grape varieties of the Zitsa region, in Greece.

The use of immobilized yeast technology and its advantages in sparkling wine production was chosen for rose and white sparkling wine production, aiming at the study and brand development of a traditional local sparkling wine, mainly rose, which is produced from grape varieties cultivated at a local scale with the "rural" method, in Zitsa region, Ioannina, Greece. In all cases the double-layer immobilization method was used. Sodium alginate was used in the same concentration in all cases, for the external layer of the beads.

Role of plasma membrane transporters in muscle metabolism.

Muscle plays a major role in metabolism. Thus it is a major glucose-utilizing tissue in the absorptive state, and changes in muscle insulin-stimulated glucose uptake alter whole-body glucose disposal. In some conditions, muscle preferentially uses lipid substrates, such as fatty acids or ketone bodies.

GLUT1 glucose transporter gene transcription is repressed by Sp3. Evidence for a regulatory role of Sp3 during myogenesis.

GLUT1 glucose transporters are highly expressed in proliferating and transformed cells as well as in tissues during fetal life. However, the mechanisms that regulate GLUT1 gene expression remain largely unknown. Here, we demonstrate that Sp3 proteins bind to the GLUT1 proximal promoter gene and inhibit transcriptional activity in muscle and non-muscle cells.

Factors involved in GLUT-1 glucose transporter gene transcription in cardiac muscle.

Glucose constitutes a major fuel for the heart, and high glucose uptake during fetal development is coincident with the highest level of expression of the glucose transporter GLUT-1 during life. We have previously reported that GLUT-1 is repressed perinatally in rat heart, and GLUT-4, which shows a low level of expression in the fetal stage, becomes the main glucose transporter in the adult. Here, we show that the perinatal expression of GLUT-1 and GLUT-4 glucose transporters in heart is controlled directly at the level of gene transcription.

Cyclic adenosine 3',5'-monophosphate regulates GLUT4 and GLUT1 glucose transporter expression and stimulates transcriptional activity of the GLUT1 promoter in muscle cells.

We have previously reported that innervation-dependent basal contractile activity regulates in an inverse manner the expression of GLUT1 and GLUT4 glucose transporters in skeletal muscle. Based on the facts that muscle innervation decreases and muscle denervation increases cAMP levels, we investigated whether cAMP might mediate the effects of innervation/denervation on glucose transporter expression. Treatment of L6E9 myotubes with 8-bromo-cAMP, forskolin, or monobutyryl-8-bromo-cAMP led to a marked decrease in GLUT4 protein levels; 8-bromo-cAMP also diminished GLUT4 messenger RNA (mRNA), suggesting pretranslational repression.

Myogenesis and MyoD down-regulate Sp1. A mechanism for the repression of GLUT1 during muscle cell differentiation.

Muscle cell differentiation caused a reduction of glucose transport, GLUT1 glucose transporter expression, and GLUT1 mRNA levels. A fragment of 2.1 kilobases of the rat GLUT1 gene linked to chloramphenicol acetyltransferase drove transcriptional activity in myoblasts, and differentiation caused a decrease in transcription.