Publications by authors named "Tyrrell D"

Spectral flow cytometry provides greater insights into cellular heterogeneity by simultaneous measurement of up to 50 markers. However, analyzing such high-dimensional (HD) data is complex through traditional manual gating strategy. To address this gap, we developed CAFE as an open-source Python-based web application with a graphical user interface.

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The main protease of SARS-CoV-2 is an essential enzyme required for polyprotein cleavage during viral replication and thus is an excellent target for development of direct-acting antiviral compounds. Continued research efforts have elucidated several peptidic small molecules like GC376, boceprevir, and nirmatrelvir with potent anticoronaviral activity bearing optimized amino acid side chain residues. To reduce synthetic complexity and cost, we used simple chemical surrogates that were commercially readily available to develop new inhibitors that mimic the potency of these drug compounds.

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Background: Group A streptococci (Strep A) orStreptococcus pyogenes is a major human pathogen causing an estimated 500,000 deaths worldwide each year. Disease can range from mild pharyngitis to more severe infections, such as necrotizing fasciitis, septicemia, and toxic shock syndrome. Untreated, Strep A infection can lead to the serious post streptococcal pathologies of rheumatic fever/rheumatic heart disease and post-streptococcal glomerulonephritis.

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Article Synopsis
  • Flow cytometry is a technique for analyzing immune cells, and spectral flow cytometry enhances this by allowing for high-dimensional analysis, addressing the limitations of traditional methods.
  • A novel analysis pipeline was developed to better handle data from large antibody panels, helping to identify rare T cell populations in aging by applying advanced methods like dimensionality reduction and unsupervised clustering.
  • The study compared T cell clusters from young and aged mice, revealing significant age-related differences in T cell subsets, and demonstrated the pipeline's effectiveness with human PBMC datasets, potentially paving the way for new therapeutic targets in age-related immune issues.
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Obesity is a major risk factor for atrial fibrillation (AF) the most common serious cardiac arrhythmia, but the molecular mechanisms underlying diet-induced AF remain unclear. In this study, we subjected mice to a chronic high-fat diet and acute sympathetic activation ('two-hit' model) to study the mechanisms by which diet-induced obesity promotes AF. Surface electrocardiography revealed that diet-induced obesity and sympathetic activation synergize during intracardiac tachypacing to induce AF.

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Background: The 78-kDa glucose-regulated protein (GRP78) expressed on the cell surface (csGRP78) has been reported to regulate tissue factor (TF) procoagulant activity (PCA) in lesion-resident endothelial cells (ECs), which is further enhanced by circulating anti-GRP78 autoantibodies that bind to the Leu-Leu epitope in GRP78.

Objectives: Determine the effects of the engagement of the anti-GRP78 autoantibody to csGRP78 on ECs and the underlying mechanisms that impact TF PCA.

Methods: Immunofluorescent staining was used to determine the presence of csGRP78 in tumor necrosis factor α-treated ECs.

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Background & Aims: An optimal HCV vaccine requires the induction of antibodies that neutralise the infectivity of many heterogenous viral isolates. In this study, we have focused on determining the optimal recombinant envelope glycoprotein component to elicit cross-neutralising antibodies against global HCV genotypes. We compared the immunoreactivity and antigenicity of the HCV genotype 1a strain H77C-derived envelope glycoprotein heterodimer gpE1/gpE2 with that of recombinant gpE2 alone.

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Flow cytometry is a widely used technique for immune cell analysis, offering insights into cell composition and function. Spectral flow cytometry allows for high-dimensional analysis of immune cells, overcoming limitations of conventional flow cytometry. However, analyzing data from large antibody panels can be challenging using traditional bi-axial gating strategies.

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The number of adults living with cystic fibrosis (CF) has already increased significantly because of drastic improvements in life expectancy attributable to advances in treatment, including the development of highly effective modulator therapy. Chronic airway inflammation in CF contributes to morbidity and mortality, and aging processes like inflammaging and cell senescence influence CF pathology. Our results show that single-cell RNA sequencing data, human primary bronchial epithelial cells from non-CF and CF donors, a CF bronchial epithelial cell line, and Cftr-knockout (Cftr-/-) rats all demonstrated increased cell senescence markers in the CF bronchial epithelium.

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Article Synopsis
  • - Multiple system atrophy (MSA) is a rare, rapidly progressing neurodegenerative disease characterized by the presence of alpha-synuclein inclusions and results in severe brain damage, including demyelination and inflammation.
  • - Researchers used a modified AAV to study the role of CD8+ T cells in MSA by creating a mouse model, revealing significant infiltration of these cells into the striatum after inducing MSA-related pathology.
  • - Findings showed that while CD8+ T cells do not drive MSA progression, they play a role in modulating neuroinflammation and demyelination, which alters disease responses.
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Many postdoctoral fellows and scholars who hope to secure tenure-track faculty positions in the United States apply to the National Institutes of Health (NIH) for a Pathway to Independence Award. This award has two phases (K99 and R00) and provides funding for up to 5 years. Using NIH data for the period 2006-2022, we report that ~230 K99 awards were made every year, representing up to ~$250 million annual investment.

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This study explores the relationship between structural alterations of nirmatrelvir, such as homologation and deuteration, and metabolic stability of newly synthesized derivatives. We developed a reliable synthetic protocol toward dideutero-nirmatrelvir and its homologated analogues with high isotopic incorporation. Deuteration of the primary metabolic site of nirmatrelvir provides a 3-fold improvement of its human microsomal stability but is accompanied by an increased metabolism rate at secondary sites.

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Itaconate has emerged as a critical immunoregulatory metabolite. Here, we examined the therapeutic potential of itaconate in atherosclerosis. We found that both itaconate and the enzyme that synthesizes it, aconitate decarboxylase 1 (Acod1, also known as immune-responsive gene 1 [IRG1]), are upregulated during atherogenesis in mice.

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Mitochondria are cellular organelles critical for ATP production and are particularly relevant to cardiovascular diseases including heart failure, atherosclerosis, ischemia-reperfusion injury, and cardiomyopathies. With advancing age, even in the absence of clinical disease, mitochondrial homeostasis becomes disrupted (e.g.

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Aging is a strong risk factor for atherosclerosis and induces accumulation of memory CD8 T cells in mice and humans. Biological changes that occur with aging lead to enhanced atherosclerosis, yet the role of aging on CD8 T cells during atherogenesis is unclear. In this study, using femle mice, we found that depletion of CD8 T cells attenuated atherogenesis in aged, but not young, animals.

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There is an urgent need to better understand the impact of different severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants on immune response and disease dynamics to facilitate better intervention strategies. Here, we show that SARS-CoV-2 variants differentially affect host immune responses. The magnitude and quantity of cytokines and chemokines were comparable in those infected with the Wuhan strain and the Delta variant.

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The targeted screening and sequencing approaches for COVID-19 surveillance need to be adjusted to fit the evolving surveillance objectives which necessarily change over time. We present the development of variant screening assays that can be applied to new targets in a timely manner and enable multiplexing of targets for efficient implementation in the laboratory. By targeting the HV69/70 deletion for Alpha, K417N for Beta, K417T for Gamma, and HV69/70 deletion plus K417N for sub-variants BA.

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For any controlled human infection model (CHIM), a safe, standardized, and biologically relevant challenge inoculum is necessary. For hepatitis C virus (HCV) CHIM, we propose that human-derived high-titer inocula of several viral genotypes with extensive virologic, serologic, and molecular characterizations should be the most appropriate approach. These inocula should first be tested in human volunteers in a step-wise manner to ensure safety, reproducibility, and curability prior to using them for testing the efficacy of candidate vaccines.

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Type III interferons (IFN-lambdas, IFN-λs) are important antiviral cytokines that can also modulate immune responses by acting through a heterodimeric receptor composed of the specific and limited expressed IFN-λR1 chain and the ubiquitous IL-10R2 chain, which is shared with IL-10 family cytokines. Conflicting data have been reported regarding which cells express the IFN-λR1 subunit and directly respond to IFN-λs. This is, in part, owing to transcript levels of the IFN-λR1 gene, , not always correlating with cell surface protein levels.

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An approach to assess severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (and past infection) was developed. For virus detection, the SARS-CoV-2 virus nucleocapsid protein (NP) was targeted. To detect the NP, antibodies were immobilized on magnetic beads to capture the NPs, which were subsequently detected using rabbit anti-SARS-CoV-2 nucleocapsid antibodies and alkaline phosphatase (AP)-conjugated anti-rabbit antibodies.

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Interferon regulatory factors (IRFs) are key elements of antiviral innate responses that regulate the transcription of interferons (IFNs) and IFN-stimulated genes (ISGs). While the sensitivity of human coronaviruses to IFNs has been characterized, antiviral roles of IRFs during human coronavirus infection are not fully understood. Type I or II IFN treatment protected MRC5 cells from human coronavirus 229E infection, but not OC43.

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Many postdoctoral fellows and scholars who hope to secure tenure-track faculty positions in the United States apply to the National Institutes of Health (NIH) for a Pathway to Independence Award. This award has two phases (K99 and R00) and provides funding for up to five years. Using NIH data for the period 2006-2022, we report that ~230 K99 awards were made every year, representing up to ~$250 million annual investment.

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A sensor capable of quantifying both anti-SARS-CoV-2 spike receptor-binding domain (RBD) antibody levels and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus in saliva and serum was developed. This was accomplished by exploiting the enzymatic reaction of maltose and orthophosphate (PO) in the presence of maltose phosphorylase to generate an equivalent amount of glucose that was detected using a commercial glucometer test strip and a potentiostat. Important for this approach is the ability to generate PO in an amount that is directly related to the concentration of the analytes.

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The National Institute on Aging sponsored a symposium at the Gerontological Society of America (GSA) annual meeting in Indianapolis, Indiana, to discuss recent discoveries related to senescent and inflammatory mechanisms in aging and disease. Consistent with the 2022 Biological Sciences GSA program led by Dr. Rozalyn Anderson, the symposium featured early-stage investigators and a leader in the field of geroscience research.

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