178 research outputs found
The Serums Tool-Chain:Ensuring Security and Privacy of Medical Data in Smart Patient-Centric Healthcare Systems
Digital technology is permeating all aspects of human society and life. This leads to humans becoming highly dependent on digital devices, including upon digital: assistance, intelligence, and decisions. A major concern of this digital dependence is the lack of human oversight or intervention in many of the ways humans use this technology. This dependence and reliance on digital technology raises concerns in how humans trust such systems, and how to ensure digital technology behaves appropriately. This works considers recent developments and projects that combine digital technology and artificial intelligence with human society. The focus is on critical scenarios where failure of digital technology can lead to significant harm or even death. We explore how to build trust for users of digital technology in such scenarios and considering many different challenges for digital technology. The approaches applied and proposed here address user trust along many dimensions and aim to build collaborative and empowering use of digital technologies in critical aspects of human society
An emerging role for NAADP-mediated Ca2+ signaling in the pancreatic beta-cell
Several recent reports, including one in this journal, have reignited the debate about whether the calcium-mobilizing messenger, nicotinic adenine nucleotide diphosphate (NAADP) plays a central role in the regulation of calcium signaling in pancreatic beta-cells. 1-5 These studies have highlighted a role for NAADP-induced Ca2+ mobilization not only in mediating the effects of the incretin, GLP-1 and the autocrine proliferative effects of insulin, but also possibly a fundamental role in glucose-mediated insulin secretion in the pancreatic beta-cell.</p
NAD+ protects against EAE by regulating CD4+ T-cell differentiation
CD4+ T cells are involved in the development of autoimmunity, including multiple sclerosis (MS). Here we show that nicotinamide adenine dinucleotide (NAD+) blocks experimental autoimmune encephalomyelitis (EAE), a mouse model of MS, by inducing immune homeostasis through CD4+IFNγ+IL-10+ T cells and reverses disease progression by restoring tissue integrity via remyelination and neuroregeneration. We show that NAD+ regulates CD4+ T-cell differentiation through tryptophan hydroxylase-1 (Tph1), independently of well-established transcription factors. In the presence of NAD+, the frequency of T-bet−/− CD4+IFNγ+ T cells was twofold higher than wild-type CD4+ T cells cultured in conventional T helper 1 polarizing conditions. Our findings unravel a new pathway orchestrating CD4+ T-cell differentiation and demonstrate that NAD+ may serve as a powerful therapeutic agent for the treatment of autoimmune and other diseases
Lung macrophage scavenger receptor SR-A6 (MARCO) is an adenovirus type-specific virus entry receptor
<div><p>Macrophages are a diverse group of phagocytic cells acting in host protection against stress, injury, and pathogens. Here, we show that the scavenger receptor SR-A6 is an entry receptor for human adenoviruses in murine alveolar macrophage-like MPI cells, and important for production of type I interferon. Scavenger receptors contribute to the clearance of endogenous proteins, lipoproteins and pathogens. Knockout of SR-A6 in MPI cells, anti-SR-A6 antibody or the soluble extracellular SR-A6 domain reduced adenovirus type-C5 (HAdV-C5) binding and transduction. Expression of murine SR-A6, and to a lower extent human SR-A6 boosted virion binding to human cells and transduction. Virion clustering by soluble SR-A6 and proximity localization with SR-A6 on MPI cells suggested direct adenovirus interaction with SR-A6. Deletion of the negatively charged hypervariable region 1 (HVR1) of hexon reduced HAdV-C5 binding and transduction, implying that the viral ligand for SR-A6 is hexon. SR-A6 facilitated macrophage entry of HAdV-B35 and HAdV-D26, two important vectors for transduction of hematopoietic cells and human vaccination. The study highlights the importance of scavenger receptors in innate immunity against human viruses.</p></div
Uncovering a neurological protein signature for severe COVID-19
Coronavirus disease of 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has sparked a global pandemic with severe complications and high morbidity rate. Neurological symptoms in COVID-19 patients, and neurological sequelae post COVID-19 recovery have been extensively reported. Yet, neurological molecular signature and signaling pathways that are affected in the central nervous system (CNS) of COVID-19 severe patients remain still unknown and need to be identified. Plasma samples from 49 severe COVID-19 patients, 50 mild COVID-19 patients, and 40 healthy controls were subjected to Olink proteomics analysis of 184 CNS-enriched proteins. By using a multi-approach bioinformatics analysis, we identified a 34-neurological protein signature for COVID-19 severity and unveiled dysregulated neurological pathways in severe cases. Here, we identified a new neurological protein signature for severe COVID-19 that was validated in different independent cohorts using blood and postmortem brain samples and shown to correlate with neurological diseases and pharmacological drugs. This protein signature could potentially aid the development of prognostic and diagnostic tools for neurological complications in post-COVID-19 convalescent patients with long term neurological sequelae
Innate Immune Response of Human Alveolar Macrophages during Influenza A Infection
Alveolar macrophages (AM) are one of the key cell types for initiating inflammatory and immune responses to influenza virus in the lung. However, the genome-wide changes in response to influenza infection in AM have not been defined. We performed gene profiling of human AM in response to H1N1 influenza A virus PR/8 using Affymetrix HG-U133 Plus 2.0 chips and verified the changes at both mRNA and protein levels by real-time RT-PCR and ELISA. We confirmed the response with a contemporary H3N2 influenza virus A/New York/238/2005 (NY/238). To understand the local cellular response, we also evaluated the impact of paracrine factors on virus-induced chemokine and cytokine secretion. In addition, we investigated the changes in the expression of macrophage receptors and uptake of pathogens after PR/8 infection. Although macrophages fail to release a large amount of infectious virus, we observed a robust induction of type I and type III interferons and several cytokines and chemokines following influenza infection. CXCL9, 10, and 11 were the most highly induced chemokines by influenza infection. UV-inactivation abolished virus-induced cytokine and chemokine response, with the exception of CXCL10. The contemporary influenza virus NY/238 infection of AM induced a similar response as PR/8. Inhibition of TNF and/or IL-1β activity significantly decreased the secretion of the proinflammatory chemokines CCL5 and CXCL8 by over 50%. PR/8 infection also significantly decreased mRNA levels of macrophage receptors including C-type lectin domain family 7 member A (CLEC7A), macrophage scavenger receptor 1 (MSR1), and CD36, and reduced uptake of zymosan. In conclusion, influenza infection induced an extensive proinflammatory response in human AM. Targeting local components of innate immune response might provide a strategy for controlling influenza A infection-induced proinflammatory response in vivo
Longitudinal cellular and humoral immune responses following COVID-19 BNT162b2-mRNA-based booster vaccination of craft and manual workers in Qatar
BackgroundIn March 2020, the rapid spread of SARS-CoV-2 prompted global vaccination campaigns to mitigate COVID-19 disease severity and mortality. The 2-dose BNT162b2-mRNA vaccine effectively reduced infection and mortality rates, however, waning vaccine effectiveness necessitated the introduction of a third vaccine dose or booster.AimTo assess the magnitude and longevity of booster-induced immunity, we conducted a longitudinal study of SARS-CoV-2 specific cellular and humoral immune responses among Qatar’s vulnerable craft and manual worker community. We also investigated the impact of prior naturally acquired immunity on booster vaccination efficacy.MethodsSeventy healthy participants were enrolled in the study, of whom half had prior SARS-CoV-2 infection. Blood samples were collected before and after booster vaccination to evaluate immune responses through SARS-CoV-2 specific ELISpots, IgG ELISA, neutralization assays, and flow cytometric immunophenotyping.ResultsT cell analysis revealed increased Th1 cytokine responses, marked by enhanced IFN-γ release, in recently infected participants, which was further enhanced by booster vaccination for up to 6-months. Furthermore, booster vaccination stimulated cytotoxic responses in infection-naïve participants, characterized by granzyme B production. Both natural SARS-CoV-2 infection and booster vaccination induced robust and durable SARS-CoV-2 specific humoral immune responses, with high neutralizing antibody levels. Prior natural infection was also linked to an increased number of class-switched B cells prior to booster vaccination.ConclusionsThese findings underscore the importance of booster vaccination in enhancing anti-viral immunity across both infection-naïve and previously infected individuals, enhancing distinct arms of the anti-viral immune response and prolonging naturally acquired immunity
Scavenger receptors and β-glucan receptors participate in the recognition of yeasts by murine macrophages
Objectives: Numerous receptors have been implicated in recognition of pathogenic fungi by macrophages, including the -glucan receptor dectin-1. The role of scavenger receptors (SRs) in anti-fungal immunity is not well characterized. Methods: We studied uptake of unopsonized Saccharomycetes cerevisiae (zymosan) and live Candida albicans yeasts as well as zymosan-stimulated production in J774 macrophage-like cells and peritoneal exudate macrophages (PEMs). The role of different receptors was assessed with the use of competitive ligands, transfected cells and receptor-deficient macrophages. Results: The uptake of zymosan by untreated J774 cells was mediated approximately half by SRs and half by a -glucan receptor which was distinct from dectin-1 and not linked to stimulation of production. Ligands of -glucan receptors and of SRs also inhibited uptake of C. albicans by macrophages (J774 cells and PEMs). In macrophages pretreated with a CpG motif-containing oligodeoxynucleotide (CpG-ODN) the relative contribution of SRs to yeast uptake increased and that of -glucan receptors decreased. Whereas the class A SR MARCO participated in the uptake of both zymosan and C. albicans by CpG-ODN-pretreated, but not untreated macrophages, the related receptor SR-A/CD204 was involved in the uptake of zymosan, but not of C. albicans. The reduction of zymosan-stimulated production observed in DS-pretreated J774 cells and in class A SRs-deficient PEMs suggest that class A SRs mediate part of this process. Conclusions: Our results revealed that SRs belong to a redundant system of receptors for yeasts. Binding of yeasts to different receptors in resting versus CpG-ODN-pre-exposed macrophages may differentially affect polarization of adaptive immune responses
Genetic Variants in MARCO Are Associated with the Susceptibility to Pulmonary Tuberculosis in Chinese Han Population
BACKGROUND: Susceptibility to tuberculosis is not only determined by Mycobacterium tuberculosis infection, but also by the genetic component of the host. Macrophage receptor with a collagenous structure (MARCO) is essential components required for toll like receptor-signaling in macrophage response to Mycobacterium tuberculosis, which may contribute to tuberculosis risk. PRINCIPAL FINDINGS: To specifically investigated whether single nucleotide polymorphisms (SNPs) in MARCO gene are associated with pulmonary tuberculosis in Chinese Han population. By selecting tagging SNPs in MARCO gene, 17 tag SNPs were identified and genotyped in 923 pulmonary tuberculosis patients and 1033 healthy control subjects using a hospital based case-control association study. Single-point and haplotype analysis revealed an association in intron and exon region of MARCO gene. One SNP (rs17009726) was associated with susceptibility to pulmonary tuberculosis, where the carriers of the G allele had a 1.65 fold (95% CI = 1.32-2.05, p(corrected) = 9.27E-5) increased risk of pulmonary tuberculosis. Haplotype analysis revealed that haplotype GC containing G allele of 17009726 and haplotype TGCC (rs17795618T/A, rs1371562G/T, rs6761637T/C, rs2011839C/T) were also associated with susceptibility to pulmonary tuberculosis (p(corrected) = 0.0001 and 0.029, respectively). CONCLUSIONS: Our study suggested that genetic variants in MARCO gene were associated with pulmonary tuberculosis susceptibility in Chinese Han population, and the findings emphasize the importance of MARCO mediated immune responses in the pathogenesis of tuberculosis
Seasonal childhood anaemia in West Africa is associated with the haptoglobin 2-2 genotype.
BACKGROUND: Anaemia is a major cause of morbidity and mortality for children in Africa. The plasma protein haptoglobin (Hp) binds avidly to free haemoglobin released following malaria-induced haemolysis. Haptoglobin polymorphisms result in proteins with altered haemoglobin-binding capacity and different antioxidant, iron-recycling, and immune functions. Previous studies examined the importance of haptoglobin polymorphism in malaria and iron homeostasis, but it is unknown whether haptoglobin genotype might be a risk factor for anaemia in children in a malaria-endemic area. METHODS AND FINDINGS: A cohort of 780 rural Gambian children aged 2-6 y was surveyed at the start and end of the malaria season. Samples were taken to assess haemoglobin (Hb) concentration, iron status (ferritin, zinc protoporphyrin, transferrin saturation, and soluble transferrin receptor concentration), haptoglobin concentration, alpha-1-antichymotrypsin (a measure of inflammation), and malaria parasites on blood film. We extracted DNA and genotyped for haptoglobin, sickle cell, and glucose-6-phosphate (G6PD) deficiency. Mean Hb levels fell over the malaria season. Children with the haptoglobin 2-2 genotype (17%) had a greater mean drop in Hb level over the malaria season (an 8.9 g/l drop; confidence interval [CI] 5.7, 12.1) compared to other children (a 5.1 g/l drop; CI 3.8, 6.4). In multivariate regression analysis, controlling for baseline Hb level, age group, village, malaria parasites on blood film, iron status, haptoglobin concentration, and G6PD deficiency, haptoglobin genotype predicted Hb level at the end of the malaria season (p = 0.0009, coefficient = -4.2). Iron status was not influenced by haptoglobin genotype. CONCLUSIONS: The finding that haptoglobin 2-2 genotype is a risk factor for anaemia in children in a malaria-endemic area may reflect the reduced ability of the Hp2-2 polymer to scavenge free haemoglobin-iron following malaria-induced haemolysis. The magnitude of the effect of haptoglobin genotype (4 g/l Hb difference, p = 0.0009) was comparable to that of G6PD deficiency or HbAS (3 g/l difference, p = 0.03; and 2 g/l difference, p = 0.68, respectively)
- …
