Peptide immunotherapy in allergic asthma generates IL-10-dependent immunological tolerance associated with linked epitope suppression

Treatment of patients with allergic asthma using low doses of peptides containing T cell epitopes from Fel d 1, the major cat allergen, reduces allergic sensitization and improves surrogate markers of disease. Here, we demonstrate a key immunological mechanism, linked epitope suppression, associated with this therapeutic effect. Treatment with selected epitopes from a single allergen resulted in suppression of responses to other ("linked") epitopes within the same molecule. This phenomenon was induced after peptide immunotherapy in human asthmatic subjects and in a novel HLA-DR1 transgenic mouse model of asthma. Tracking of allergen-specific T cells using DR1 tetramers determined that suppression was associated with the induction of interleukin (IL)-10(+) T cells that were more abundant than T cells specific for the single-treatment peptide and was reversed by anti -IL-10 receptor administration. Resolution of airway pathophysiology in this model was associated with reduced recruitment, proliferation, and effector function of allergen-specific Th2 cells. Our results provide, for the first time, in vivo evidence of linked epitope suppression and IL-10 induction in both human allergic disease and a mouse model designed to closely mimic peptide therapy in humans

Assessing Theoretical Conclusions With Blinded Inference to Investigate a Potential Inference Crisis

Scientific advances across a range of disciplines hinge on the ability to make inferences about unobservable theoretical entities on the basis of empirical data patterns. Accurate inferences rely on both discovering valid, replicable data patterns and accurately interpreting those patterns in terms of their implications for theoretical constructs. The replication crisis in science has led to widespread efforts to improve the reliability of research findings, but comparatively little attention has been devoted to the validity of inferences based on those findings. Using an example from cognitive psychology, we demonstrate a blinded-inference paradigm for assessing the quality of theoretical inferences from data. Our results reveal substantial variability in experts’ judgments on the very same data, hinting at a possible inference crisis

Studies on the mechanism of histone deacetylase enzymes

The nucleosome core particle, which is the fundamental building block of chromatin, is composed of 146–147 base pairs of DNA wrapped around a histone octomer containing one H3–H4 tetramer and two H2A–H2B dimers (Luger 2003). Histone proteins are the sites of many different types of posttranslational modifications including acetylation, phosphorylation, methylation, ubiquitination, sumolation, and ADP-ribosylation (Khorasanizadeh 2004). Dynamic acetylation of the ϵ-amino group of specific lysine residues on the N-terminal tails of histones is achieved by histone acetyltransferase (HAT) and histone deacetylase (HDAC) enzymes (Grunstein 1997). Hyperacetylation is associated with euchromatin, which has a more open conformation allowing for increased gene expression. On the other hand, hypoacetylation is found in condensed heterochromatin and is coupled with repression of transcriptional activity (de Ruijter, van Gennip et al. 2003; Hake, Xiao et al. 2004). HDAC enzymes have been organized into three phylogenetic classes based on sequence homology, inhibitor sensitivity, and cofactor necessity (de Ruijter, van Gennip et al. 2003). The class I and II zinc-dependent HDACs participate in cell cycle control and growth regulation, and consequently their inhibitors have demonstrated the ability to arrest tumor cell growth, induce differentiation, and cause apoptosis (Marks, Miller et al. 2003). HDACs play integral roles in cancer gene regulation and cancer proliferation and as a result, HDAC inhibitors represent promising new chemotherapies for the treatment of certain hematological malignancies like acute leukemias, non-Hodgkins lymphoma, and cutaneous T-cell lymphoma, as well as for tumors of the breast, colon, lung, prostate and stomach (Huang, Sloan et al. 2003; Marks, Miller et al. 2003; Hake, Xiao et al. 2004; Somech, Izraeli et al. 2004). Thorough characterization of HDAC activity is paramount not only to our understanding of gene-specific transcriptional regulation, but indispensable to our complete understanding of cancer pathology. Despite the vital role played by class I and II zinc-dependent HDAC enzymes in gene expression and cancer, the exact mechanism of their catalytic activity remains unknown. In this dissertation, a continuous spectrophotomeric assay for monitoring HDAC activity will be described. Details of the kinetic and chemical mechanism of HDLP, a histone deacetylase-like protein from A. aeolicus will be presented. Mutational analysis of catalytically important residues of HDLP will be discussed to provide further insight into the mechanism of this intriguing class of enzymes

Studies on the mechanism of histone deacetylase enzymes

The nucleosome core particle, which is the fundamental building block of chromatin, is composed of 146–147 base pairs of DNA wrapped around a histone octomer containing one H3–H4 tetramer and two H2A–H2B dimers (Luger 2003). Histone proteins are the sites of many different types of posttranslational modifications including acetylation, phosphorylation, methylation, ubiquitination, sumolation, and ADP-ribosylation (Khorasanizadeh 2004). Dynamic acetylation of the ϵ-amino group of specific lysine residues on the N-terminal tails of histones is achieved by histone acetyltransferase (HAT) and histone deacetylase (HDAC) enzymes (Grunstein 1997). Hyperacetylation is associated with euchromatin, which has a more open conformation allowing for increased gene expression. On the other hand, hypoacetylation is found in condensed heterochromatin and is coupled with repression of transcriptional activity (de Ruijter, van Gennip et al. 2003; Hake, Xiao et al. 2004). HDAC enzymes have been organized into three phylogenetic classes based on sequence homology, inhibitor sensitivity, and cofactor necessity (de Ruijter, van Gennip et al. 2003). The class I and II zinc-dependent HDACs participate in cell cycle control and growth regulation, and consequently their inhibitors have demonstrated the ability to arrest tumor cell growth, induce differentiation, and cause apoptosis (Marks, Miller et al. 2003). HDACs play integral roles in cancer gene regulation and cancer proliferation and as a result, HDAC inhibitors represent promising new chemotherapies for the treatment of certain hematological malignancies like acute leukemias, non-Hodgkins lymphoma, and cutaneous T-cell lymphoma, as well as for tumors of the breast, colon, lung, prostate and stomach (Huang, Sloan et al. 2003; Marks, Miller et al. 2003; Hake, Xiao et al. 2004; Somech, Izraeli et al. 2004). Thorough characterization of HDAC activity is paramount not only to our understanding of gene-specific transcriptional regulation, but indispensable to our complete understanding of cancer pathology. Despite the vital role played by class I and II zinc-dependent HDAC enzymes in gene expression and cancer, the exact mechanism of their catalytic activity remains unknown. In this dissertation, a continuous spectrophotomeric assay for monitoring HDAC activity will be described. Details of the kinetic and chemical mechanism of HDLP, a histone deacetylase-like protein from A. aeolicus will be presented. Mutational analysis of catalytically important residues of HDLP will be discussed to provide further insight into the mechanism of this intriguing class of enzymes

Evidence for access: systematic scoping review of access systems in general practice

Background: access to GP appointments is increasingly challenging in many high-income countries, with an overstretched workforce and rising demand. Various access systems have been developed and evaluated internationally.Aim: we aimed to systematically consolidate the current international evidence base related to different types of GP access systems.Design and setting: a scoping review examining international literature.Method: literature searches were run across relevant databases in May 2022. Title, abstract and full text screenings were carried out. Data from included studies were extracted and mapped to synthesise the components and aims within different GP access systems.Results: 49 studies were included in the review. The majority of these were set in the UK. Some access systems featured heavily in the literature, such as Advanced Access, telephone triage and online consultations, and others less so. There were two key strategies adopted by systems which related to either changing appointment capacity or modifying patient pathways. Components related to these strategies are summarised and illustrated as a schematic representation. Most rationales behind access systems were practice, rather than patient, focused. 'Add on' systems and aims for efficiency became more popular in recent years.Conclusion: the synthesis provides a useful tool in understanding access systems' aims, design, and implementation. With focus on alleviating demand, patient-focused outcomes appear to be under investigated and potentially overlooked during design and implementation. More recently, digital services are promoted as offering patient choice and convenience. But a context where demand outweighs resources challenges the premise that extending choice is possible.</p

Ex vivo study of molecular changes of stained teeth following hydrogen peroxide and peroxymonosulfate treatments.

White teeth can give confidence and tend to be associated with a healthier lifestyle in modern society. Therefore, tooth-bleaching strategies have been developed, including the use of hydrogen peroxide. Recently, peroxymonosulfate has been introduced as an alternative bleaching method to hydrogen peroxide. Although both chemicals are oxidizing agents, their effects on the molecular composition of the stained teeth are yet unknown. In this study, the molecular profiles of teeth bleached with hydrogen peroxide and peroxymonosulfate were compared using Liquid Chromatography-Tandem Mass Spectrometry. Statistical analyses were used to assess the samples. In addition, reference spectral libraries and in silico tools were used to perform metabolite annotation. Overall, principal component analysis showed a strong separation between control and hydrogen peroxide and peroxymonosulfate samples (p &lt; 0.001). The analysis of molecular changes revealed amino acids and dipeptides in stained teeth samples after hydrogen peroxide and peroxymonosulfate treatments. Noteworthy, the two bleaching methods led to distinct molecular profiles. For example, diterpenoids were more prevalent after peroxymonosulfate treatment, while a greater abundance of alkaloids was detected after hydrogen peroxide treatment. Whereas non-bleached samples (controls) showed mainly lipids. Therefore, this study shows how two different tooth-whitening peroxides could affect the molecular profiles of human teeth

Ex vivo study of molecular changes of stained teeth following hydrogen peroxide and peroxymonosulfate treatments

Abstract White teeth can give confidence and tend to be associated with a healthier lifestyle in modern society. Therefore, tooth-bleaching strategies have been developed, including the use of hydrogen peroxide. Recently, peroxymonosulfate has been introduced as an alternative bleaching method to hydrogen peroxide. Although both chemicals are oxidizing agents, their effects on the molecular composition of the stained teeth are yet unknown. In this study, the molecular profiles of teeth bleached with hydrogen peroxide and peroxymonosulfate were compared using Liquid Chromatography-Tandem Mass Spectrometry. Statistical analyses were used to assess the samples. In addition, reference spectral libraries and in silico tools were used to perform metabolite annotation. Overall, principal component analysis showed a strong separation between control and hydrogen peroxide and peroxymonosulfate samples (p < 0.001). The analysis of molecular changes revealed amino acids and dipeptides in stained teeth samples after hydrogen peroxide and peroxymonosulfate treatments. Noteworthy, the two bleaching methods led to distinct molecular profiles. For example, diterpenoids were more prevalent after peroxymonosulfate treatment, while a greater abundance of alkaloids was detected after hydrogen peroxide treatment. Whereas non-bleached samples (controls) showed mainly lipids. Therefore, this study shows how two different tooth-whitening peroxides could affect the molecular profiles of human teeth