Control of Epstein-Barr virus infection in vitro by T helper cells specific for virion glycoproteins

Epstein-Barr virus (EBV) establishes lifelong persistent infections in humans by latently infecting B cells, with occasional cycles of reactivation, virus production, and reinfection. Protective immunity against EBV is mediated by T cells, but the role of EBV-specific T helper (Th) cells is still poorly defined. Here, we study the Th response to the EBV lytic cycle proteins BLLF1 (gp350/220), BALF4 (gp110), and BZLF1 and show that glycoprotein-specific Th cells recognize EBV-positive cells directly; surprisingly, a much higher percentage of target cells than those expressing lytic cycle proteins were recognized. Antigen is efficiently transferred to bystander B cells by receptor-mediated uptake of released virions, resulting in recognition of target cells incubated with <1 virion/cell. T cell recognition does not require productive infection and occurs early after virus entry before latency is established. Glycoprotein-specific Th cells are cytolytic and inhibit proliferation of lymphoblastoid cell lines (LCL) and the outgrowth of LCL after infection of primary B cells with EBV. These results establish a novel role for glycoprotein-specific Th cells in the control of EBV infection and identify virion proteins as important immune targets. These findings have implications for the treatment of diseases associated with EBV and potentially other coated viruses infecting MHC class II–positive cells

Involvement of the extracellular matrix and integrin signalling proteins in skeletal muscle glucose uptake

Whole‐body euglycaemia is partly maintained by two cellular processes that encourage glucose uptake in skeletal muscle, the insulin‐ and contraction‐stimulated pathways, with research suggesting convergence between these two processes. The normal structural integrity of the skeletal muscle requires an intact actin cytoskeleton as well as integrin‐associated proteins, and thus those structures are likely fundamental for effective glucose uptake in skeletal muscle. In contrast, excessive extracellular matrix (ECM) remodelling and integrin expression in skeletal muscle may contribute to insulin resistance owing to an increased physical barrier causing reduced nutrient and hormonal flux. This review explores the role of the ECM and the actin cytoskeleton in insulin‐ and contraction‐mediated glucose uptake in skeletal muscle. This is a clinically important area of research given that defects in the structural integrity of the ECM and integrin‐associated proteins may contribute to loss of muscle function and decreased glucose uptake in type 2 diabetes. [Image: see text

Model-based comparison of organ at risk protection between VMAT and robustly optimised IMPT plans

The comparison between intensity-modulated proton therapy (IMPT) and volume-modulated arc therapy (VMAT) plans, based on models of normal tissue complication probabilities (NTCP), can support the choice of radiation modality. IMPT irradiation plans for 50 patients with head and neck tumours originally treated with photon therapy have been robustly optimised against density and setup uncertainties. The dose distribution has been calculated with a Monte Carlo (MC) algorithm. The comparison of the plans was based on dose-volume parameters in organs at risk (OARs) and NTCP-calculations for xerostomia, sticky saliva, dysphagia and tube feeding using Langendijk's model-based approach. While the dose distribution in the target volumes is similar, the IMPT plans show better protection of OARs. Therefore, it is not the high dose confirmation that constitutes the advantage of protons, but it is the reduction of the mid-to-low dose levels compared to photons. This work investigates to what extent the advantages of proton radiation are beneficial for the patient's post-therapeutic quality of life (QoL). As a result, approximately one third of the patients examined benefit significantly from proton therapy with regard to possible late side effects. Clinical data is needed to confirm the model-based calculations

Immunodominance of Lytic Cycle Antigens in Epstein-Barr Virus-Specific CD4+ T Cell Preparations for Therapy

Epstein-Barr virus (EBV) is associated with a number of human malignancies. EBV-positive post-transplant lymphoproliferative disease in solid organ and hematopoietic stem cell transplant recipients has been successfully treated by the adoptive transfer of polyclonal EBV-specific T cell lines containing CD4+ and CD8+ T cell components. Although patients receiving T cell preparations with a higher CD4+ T cell proportion show better clinical responses, the specificity of the infused CD4+ component has remained completely unknown. We generated LCL-stimulated T cell lines from 21 donors according to clinical protocols, and analyzed the antigen specificity of the CD4+ component in EBV-specific T cell preparations using a genetically engineered EBV mutant that is unable to enter the lytic cycle, and recombinantly expressed and purified EBV proteins. Surprisingly, CD4+ T cell lines from acutely and persistently EBV-infected donors consistently responded against EBV lytic cycle antigens and autoantigens, but barely against latent cycle antigens of EBV hitherto considered principal immunotherapeutic targets. Lytic cycle antigens were predominantly derived from structural proteins of the virus presented on MHC II via receptor-mediated uptake of released viral particles, but also included abundant infected cell proteins whose presentation involved intercellular protein transfer. Importantly, presentation of virion antigens was severely impaired by acyclovir treatment of stimulator cells, as currently performed in most clinical protocols. These results indicate that structural antigens of EBV are the immunodominant targets of CD4+ T cells in LCL-stimulated T cell preparations. These findings add to our understanding of the immune response against this human tumor-virus and have important implications for the improvement of immunotherapeutic strategies against EBV

NMR evaluation of total statin content and HMG-CoA reductase inhibition in red yeast rice (Monascus spp.) food supplements

Background Red yeast rice (i.e., rice fermented with Monascus spp.), as a food supplement, is claimed to be blood cholesterol-lowering. The red yeast rice constituent monacolin K, also known as lovastatin, is an inhibitor of the hydroxymethylglutaryl-CoA (HMG-CoA) reductase. This article aims to develop a sensitive nuclear magnetic resonance (NMR) method to determine the total statin content of red yeast rice products. Methods The total statin content was determined by a 400 MHz 1H NMR spectroscopic method, based on the integration of the multiplet at δ 5.37-5.32 ppm of a hydrogen at the hexahydronaphthalene moiety in comparison to an external calibration with lovastatin. The activity of HMG-CoA reductase was measured by a commercial spectrophotometric assay kit. Results The NMR detection limit for total statins was 6 mg/L (equivalent to 0.3 mg/capsule, if two capsules are dissolved in 50 mL ethanol). The relative standard deviations were consistently lower than 11%. The total statin concentrations of five red yeast rice supplements were between 1.5 and 25.2 mg per specified daily dose. A dose-dependent inhibition of the HMG-CoA reductase enzyme activity by the red yeast rice products was demonstrated. Conclusion A simple and direct NMR assay was developed to determine the total statin content in red yeast rice. The assay can be applied for the determination of statin content for the regulatory control of red yeast rice products

Impact of T2R38 receptor polymorphisms on Pseudomonas aeruginosa infection in cystic fibrosis

The T2R38 (taste receptor 2 member 38) bitter taste receptor on respiratory epithelia detects Pseudomonas aeruginosa N-acyl-l-homoserine lactones (AHLs). In vitro, T2R38 activation by AHLs initiates calcium-mediated increases in nitric oxide production and ciliary beat frequency, dependent on polymorphisms in the TAS2R38 gene (1). In patients with chronic rhinosinusitis, the TAS2R38 genotype is proposed to modify mucosal responses to P. aeruginosa (1). Polymorphisms in the TAS2R38 gene result in two high-frequency haplotypes associated with taste perception of the bitter compound phenylthiocarbamide (2). The “taster” haplotype codes proline-alanine-valine (PAV), and the “nontaster” haplotype codes alanine-valine-isoleucine (AVI) at positions 49, 262, and 296 in the receptor protein. Responses to AHLs in vitro are greatest in PAV/PAV epithelial cells, and this genotype is reported to be protective against P. aeruginosa in the sinonasal airway (1). P. aeruginosa is the most frequently isolated respiratory pathogen in cystic fibrosis (CF), and chronic infection is associated with accelerated rates of disease progression. Determining the impact of TAS2R38 polymorphisms on P. aeruginosa infection in CF could have implications for patient risk stratification and, as naturally occurring and synthetic agonists to T2R38 are already in clinical use (3), could identify promising therapeutic targets. We characterized T2R38 localization in the CF airway and investigated the hypothesis that TAS2R38 polymorphisms would modify the prevalence and impact of P. aeruginosa infection in CF. Some of the results of these studies have previously been reported in the form of abstracts

Geo-scientific characterisation of the Boom Clay in the Netherlands in light of permanent confinement of radio-active waste

Recently, the OPERA research program has been initiated in the Netherlands. Its central objective is to develop initial, conditional safety cases for repositories in the Boom Clay and Zechstein rocksalt formations. TNO Geological Survey of the Netherlands has been granted two projects that deal with the geoscientific characterisation of the Tertiairy Boom Clay in the Netherlands, one of which is in cooperation with Utrecht University. The set-up of these projects is presented..

Human airway epithelial extracellular vesicle miRNA signature is altered upon asthma development

Background: miRNAs are master regulators of signaling pathways critically involved in asthma and are transferred between cells in extracellular vesicles (EV). We aimed to investigate whether the miRNA content of EV secreted by primary normal human bronchial epithelial cells (NHBE) is altered upon asthma development. Methods: NHBE cells were cultured at air-liquid interface and treated with interleukin (IL)-13 to induce an asthma-like phenotype. EV isolations by precipitation from basal culture medium or apical surface wash were characterized by nanoparticle tracking analysis, transmission electron microscopy, and Western blot, and EV-associated miRNAs were identified by a RT-qPCR-based profiling. Significant candidates were confirmed in EVs isolated by size-exclusion chromatography from nasal lavages of children with mild-to-moderate (n = 8) or severe asthma (n = 9), and healthy controls (n = 9). Results: NHBE cells secrete EVs to the apical and basal side. 47 miRNAs were expressed in EVs and 16 thereof were significantly altered in basal EV upon IL-13 treatment. Expression of miRNAs could be confirmed in EVs from human nasal lavages. Of note, levels of miR-92b, miR-210, and miR-34a significantly correlated with lung function parameters in children (FEV1FVC%pred and FEF25-75%pred), thus lower sEV-miRNA levels in nasal lavages associated with airway obstruction. Subsequent ingenuity pathway analysis predicted the miRNAs to regulate Th2 polarization and dendritic cell maturation. Conclusion: Our data indicate that secretion of miRNAs in EVs from the airway epithelium, in particular miR-34a, miR-92b, and miR-210, might be involved in the early development of a Th2 response in the airways and asthma

QED Corrections to Neutrino Electron Scattering

We evaluate the O(alpha) QED corrections to the recoil electron energy spectrum in the process nu_l + e --> nu_l + e (+gamma), where (+gamma) indicates the possible emission of a photon and l=e, mu or tau. The soft and hard bremsstrahlung differential cross sections are computed for an arbitrary value of the photon energy threshold. We also study the O(alpha) QED corrections to the differential cross section with respect to the total combined energy of the recoil electron and a possible accompanying photon. Their difference from the corrections to the electron spectrum is investigated. We discuss the relevance and applicability of both radiative corrections, emphasizing their role in the analysis of precise solar neutrino electron scattering experiments.Comment: 14 pages + 10 figures. Minimal changes, published versio

Reaction of porphyrin-based surface-anchored metal-organic frameworks to prolonged illumination

Crystalline surface-anchored metal–organic framework (SURMOF) thin films made from porphyrin-based organic linkers have recently been used in both photon upconversion and photovoltaic applications. While these studies showed promising results, the question of photostability in this organic–inorganic hybrid material has to be investigated before applications can be considered. Here, we combine steady-state photoluminescence, transient absorption, and time-resolved electron paramagnetic resonance spectroscopy to examine the effects of prolonged illumination on a palladium-porphyrin based SURMOF thin film. We find that phototreatment leads to a change in the material\u27s photoresponse caused by the creation of stable products of photodecomposition – likely chlorin – inside the SURMOF structure. When the mobile triplet excitons encounter such a defect site, a short-lived (80 ns) cation–anion radical pair can be formed by electron transfer, wherein the charges are localized at a porphyrin and the photoproduct site, respectively