In toxicology, steps are being taken towards more mechanism-focused and human relevant approaches to risk assessment, requiring new approaches and methods. Additionally, there is increasing emphasis by regulators on risk assessment of immunotoxicity. Here we present data from a peripheral blood mononuclear cell (PBMC) system whereby a varied set of stimuli, including those against the TCR and Toll-like receptors, enable readouts of cytokine and prostaglandin E2 (PGE2) production with monocyte, T cell and B cell viability, proliferation, and associated activation markers.
View Article and Find Full Text PDFBackground: To reduce Medicare prescription drug expenditures, the 2022 Inflation Reduction Act (IRA) allows the Centers for Medicare & Medicaid Services (CMS) to directly negotiate with drug manufacturers on Medicare prices of high-expenditure drugs (≥$200m annual spending) which meet certain eligibility criteria. However, it is unclear what proportion of high-expenditure drugs covered by Medicare, and attributable annual drug spending, would typically be eligible for CMS negotiations in a given year.
Methods: We used historical Medicare drug spending data to determine how many high-expenditure drugs, and attributable drug spending, would have been eligible for CMS negotiations had the IRA been in effect from 2016-2019, while also determining which of the IRA's eligibility criteria is most restrictive.
Activity in the basolateral amygdala complex (BLA) is needed to encode fears acquired through contact with both innate sources of danger (i.e., things that are painful) and learned sources of danger (e.
View Article and Find Full Text PDFThis study examined the effect of danger on consolidation of neutral information in two regions of the rat (male and female) medial temporal lobe: the perirhinal cortex (PRh) and basolateral amygdala complex (BLA). The neutral information was the association that forms between an auditory stimulus and a visual stimulus (labeled S2 and S1) across their pairings in sensory preconditioning. We show that, when the sensory preconditioning session is followed by a shocked context exposure, the danger shifts consolidation of the S2-S1 association from the PRh to the BLA; and does so by interacting with processes involved in encoding of the S2-S1 pairings.
View Article and Find Full Text PDFAcute and chronic neurodegenerative diseases represent an immense socioeconomic burden that drives the need for new disease modifying drugs. Common pathogenic mechanisms in these diseases are evident, suggesting that a platform neuroprotective therapy may offer effective treatments. Here we present evidence for the mode of pharmacological action of a novel neuroprotective low molecular weight dextran sulphate drug called ILB.
View Article and Find Full Text PDFNear-infrared (NIR) chemical fluorophores are promising tools for in-vivo imaging in real time but often succumb to rapid photodegradation. Indocyanine green (ICG) is the only NIR dye with regulatory approval for ocular imaging in humans; however, ICG, when employed for applications such as labelling immune cells, has limited sensitivity and does not allow precise detection of specific inflammatory events, for example leukocyte recruitment during uveitic flare-ups. We investigated the potential use of photostable novel triazole NIR cyanine (TNC) dyes for detecting and characterising activated T-cell activity within the eye.
View Article and Find Full Text PDFCD28 and CTLA-4 (CD152) play essential roles in regulating T cell immunity, balancing the activation and inhibition of T cell responses, respectively. Although both receptors share the same ligands, CD80 and CD86, the specific requirement for two distinct ligands remains obscure. In the present study, we demonstrate that, although CTLA-4 targets both CD80 and CD86 for destruction via transendocytosis, this process results in separate fates for CTLA-4 itself.
View Article and Find Full Text PDFHyperinsulinemia promotes fat accumulation, causing obesity. Being an inflammatory state, obesity can induce further inflammation and is a risk factor for HPA (hypothalamic pituitary axis) dysregulation through hypercortisolism-related hyperglycemia. In another hypothesis, the sympathetic nervous system (SNS) plays a significant role in the regulation of hormone secretion from the pancreas such as an increase in catecholamines and glucagon as well as a decrease in plasma insulin levels, a disruption on SNS activity increases insulin levels, and induces glycogenolysis in the liver and lipolysis in adipose tissue during hypoglycemia.
View Article and Find Full Text PDFThe metabolism of l-tryptophan to -formyl-l-kynurenine by indoleamine-2,3-dioxygenase 1 (IDO1) is thought to play a critical role in tumour-mediated immune suppression. Whilst there has been significant progress in elucidating the overall enzymatic mechanism of IDO1 and related enzymes, key aspects of the catalytic cycle remain poorly understood. Here we report the design, synthesis and biological evaluation of a series of tryptophan analogues which have the potential to intercept putative intermediates in the metabolism of 1 by IDO1.
View Article and Find Full Text PDFElimination of the binding of immunoglobulin Fc to Fc gamma receptors (FcγR) is highly desirable for the avoidance of unwanted inflammatory responses to therapeutic antibodies and fusion proteins. Many different approaches have been described in the literature but none of them completely eliminates binding to all of the Fcγ receptors. Here we describe a set of novel variants having specific amino acid substitutions in the Fc region at L234 and L235 combined with the substitution G236R.
View Article and Find Full Text PDFMany studies have reported that patients with psychosis, even before drug treatment, have mildly raised levels of blood cytokines relative to healthy controls. In contrast, there is a remarkable scarcity of studies investigating the cellular basis of immune function and cytokine changes in psychosis. The few flow-cytometry studies have been limited to counting the proportion of the major classes of monocyte and lymphocytes without distinguishing their pro- and anti-inflammatory subsets.
View Article and Find Full Text PDFCTLA-4 is an essential regulator of T-cell immune responses whose intracellular trafficking is a hallmark of its expression. Defects in CTLA-4 trafficking due to LRBA deficiency cause profound autoimmunity in humans. CTLA-4 rapidly internalizes via a clathrin-dependent pathway followed by poorly characterized recycling and degradation fates.
View Article and Find Full Text PDFBlockade of PD-1/PD-L1 interactions is proving an exciting, durable therapeutic modality in a range of cancers whereby T cells are released from checkpoint inhibition to revive their inherent anti-tumour activity. Here we have studied various ways to model ex vivo T cell function in order to compare the impact of the clinically utilised anti-PD-1 antibody, pembrolizumab (Keytruda) on the activation of human T cells: focussing on the release of pro-inflammatory IFNγ and anti-inflammatory IL-10 to assess functionality. Firstly, we investigated the actions of pembrolizumab in an acute model of T-cell activation with either immature or mature allogeneic dendritic cells (DCs); pembrolizumab enhanced IFNγ and IL-10 release from purified CD4+ T-cells in the majority of donors with a bias towards pro-inflammatory cytokine release.
View Article and Find Full Text PDFFibrotic disease is a major cause of mortality worldwide, with fibrosis arising from prolonged inflammation and aberrant extracellular matrix dynamics. Compromised cellular and tissue repair processes following injury, infection, metabolic dysfunction, autoimmune conditions and vascular diseases leave tissues susceptible to unresolved inflammation, fibrogenesis, loss of function and scarring. There has been limited clinical success with therapies for inflammatory and fibrotic diseases such that there remains a large unmet therapeutic need to restore normal tissue homoeostasis without detrimental side effects.
View Article and Find Full Text PDFThe cellular uptake, intracellular processing, and presentation of foreign antigen are crucial processes for eliciting an effective adaptive host response to the majority of pathogens. The effective recognition of antigen by T cells requires that it is first processed and then presented on MHC molecules that are expressed on other cells. A critical step leading to the presentation of antigen is delivering the foreign cargo to an intracellular compartment where the antigen can be processed and loaded onto MHC molecules.
View Article and Find Full Text PDFThe 5-hydroxytryptamine (5-HT) (serotonin) 5-HT receptor represents a clinical target for antagonists to deliver symptomatic relief to patients with diarrhea-predominant irritable bowel syndrome (IBS-d) or carcinoid syndrome. Unfortunately, this pharmacological strategy can present side effects (e.g.
View Article and Find Full Text PDFCD4 T cells play critical roles in directing immunity, both as T helper and as regulatory T (Treg) cells. Here, we demonstrate that hepatocytes can modulate T cell populations through engulfment of live CD4 lymphocytes. We term this phenomenon enclysis to reflect the specific enclosure of CD4 T cells in hepatocytes.
View Article and Find Full Text PDFBackground: Tubulointerstitial fibrosis is a key feature of chronic kidney diseases leading to renal failure. It is characterised by the infiltration of fibroblasts and aberrant accumulation of extracellular matrix (ECM) proteins, which are associated with progressive loss of renal function. Integrins play a major role in fibrosis, but the mechanisms through which they do this are not fully understood.
View Article and Find Full Text PDFRegulatory T cells (Treg) have a central role in controlling the activation of self-reactive T cells and maintaining peripheral tolerance in our body. Many effector mechanisms for Treg function have been described including a role for the protein CTLA-4 which is constitutively expressed by these cells. Despite its importance, there is currently little consensus in the methods and protocols for studying CTLA-4 function, which is partially due to debate over CTLA-4 function itself.
View Article and Find Full Text PDFThe amygdala is a critical substrate for learning about cues that signal danger. Less is known about its role in processing innocuous or background information. The present study addressed this question using a sensory preconditioning protocol in male rats.
View Article and Find Full Text PDFA correction to this article has been published and is linked from the HTML version of this paper. The error has been fixed in the paper.
View Article and Find Full Text PDFImmune complex (IC) deposition of IgG containing autologous antigens has been observed in autoimmunity. This can lead to IC-mediated antigen uptake and presentation by antigen presenting cells (APC) driving T cell dependent inflammation. IgG receptors (FcγRs) have been suggested to be involved in this process.
View Article and Find Full Text PDFActivated fibroblasts are considered major drivers of fibrotic disease progression through the production of excessive extracellular matrix (ECM) in response to signals from damaged epithelial and inflammatory cells. Nevertheless, epithelial cells are capable of expressing components of the ECM, cross-linking enzymes that increase its stability and are sensitive to factors involved in the early stages of fibrosis. We therefore wanted to test the hypothesis that epithelial cells can deposit ECM in response to stimulation in a comparable manner to fibroblasts.
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