Publications by authors named "Sarah K Howlett"

As the dimensionality, throughput and complexity of cytometry data increases, so does the demand for user-friendly, interactive analysis tools that leverage high-performance machine learning frameworks. Here we introduce FlowAtlas: an interactive web application that enables dimensionality reduction of cytometry data without down-sampling and that is compatible with datasets stained with non-identical panels. FlowAtlas bridges the user-friendly environment of FlowJo and computational tools in Julia developed by the scientific machine learning community, eliminating the need for coding and bioinformatics expertise.

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Article Synopsis
  • The immune system is made up of various cell types that are found in blood and tissues, but research mostly focuses on blood samples, leaving gaps in our understanding of immune variation throughout the body and across different ages.
  • Researchers analyzed RNA and surface protein expression from over 1.25 million immune cells collected from various tissues of 24 organ donors aged 20-75 years to understand these variations better.
  • They discovered that immune cell composition and function varies significantly based on tissue type and age, providing insights into how immune responses can be linked to disease across the human lifespan.
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The adoptive transfer of regulatory T-cells (Tregs) is a promising therapeutic approach in transplantation and autoimmunity. However, because large cell numbers are needed to achieve a therapeutic effect, in vitro expansion is required. By comparing their function, phenotype and transcriptomic profile against ex vivo Tregs, we demonstrate that expanded human Tregs switch their metabolism to aerobic glycolysis and show enhanced suppressive function through hypoxia-inducible factor 1-alpha (HIF1A) driven acquisition of CD73 expression.

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Dopaminergic (DA) cell replacement therapies are a promising experimental treatment for Parkinson's disease (PD) and a number of different types of DA cell-based therapies have already been trialled in patients. To date, the most successful have been allotransplants of foetal ventral midbrain but even then, the results have been inconsistent. This coupled to the ethical and logistical problems with using this tissue has meant that an alternative cell source has been sought of which human pluripotent stem cells (hPSCs) sources have proven very attractive.

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Susceptibility to multiple autoimmune diseases is associated with common gene polymorphisms influencing IL-2 signaling and T function, making T-specific expansion by IL-2 a compelling therapeutic approach to treatment. As an in vivo IL-2 half-life enhancer we used a non-targeted, effector-function-silent human IgG1 as a fusion protein. An IL-2 mutein (N88D) with reduced binding to the intermediate affinity IL-2Rβγ receptor was engineered with a stoichiometry of two IL-2N88D molecules per IgG, i.

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We have previously proposed that sequence variation of the CD101 gene between NOD and C57BL/6 mice accounts for the protection from type 1 diabetes (T1D) provided by the insulin-dependent diabetes susceptibility region 10 (Idd10), a <1 Mb region on mouse chromosome 3. In this study, we provide further support for the hypothesis that Cd101 is Idd10 using haplotype and expression analyses of novel Idd10 congenic strains coupled to the development of a CD101 knockout mouse. Susceptibility to T1D was correlated with genotype-dependent CD101 expression on multiple cell subsets, including Foxp3(+) regulatory CD4(+) T cells, CD11c(+) dendritic cells, and Gr1(+) myeloid cells.

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NK cells from NOD mice induced with poly(I:C) in vivo exhibit low cytotoxicity against a range of target cells, but the genetic mechanisms controlling this defect are yet to be elucidated. Defects in the expression of NKG2D and its ligands, the RAE-1 molecules, have been hypothesized to contribute to the reduced NK function present in NOD mice. In this study, we show that segregation of the NK-mediated killing phenotype did not correlate with the NOD Raet1 haplotype and that the large alterations in NKG2D expression previously reported on NK cells expanded in vitro were not observed in primary, poly(I:C)-elicited NK cells in vivo.

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Variants within the IL-2 (interleukin 2) and CD25 genes are associated with T1DM (Type 1 diabetes mellitus) in mice and humans respectively. Both gene products are essential for optimal immune tolerance and a partial failure to tolerize is linked to the autoimmune responses to insulin and other beta-cell proteins that precede T1DM onset. Gene variants that contribute to common disease susceptibility often alter gene expression only modestly.

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Although the first mouse embryonic stem (ES) cell lines were derived 25 years ago using feeder-layer-based blastocyst cultures, subsequent efforts to extend the approach to other mammals, including both laboratory and domestic species, have been relatively unsuccessful. The most notable exceptions were the derivation of non-human primate ES cell lines followed shortly thereafter by their derivation of human ES cells. Despite the apparent common origin and the similar pluripotency of mouse and human embryonic stem cells, recent studies have revealed that they use different signalling pathways to maintain their pluripotent status.

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It would be extremely advantageous to the analysis of disease mechanisms in the spontaneous mouse model of type 1 diabetes, the nonobese diabetic (NOD) strain, if genes in this strain could be modified in vivo using embryonic stem (ES) cells and homologous recombination. However, a NOD ES cell line with adequate germline transmission has not yet been reported. We report the development of highly germline-competent ES cell lines from the F1 hybrid of NOD and 129 for use in NOD gene targeting.

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Inhibition of DNA replication in the 1-cell mouse embryo causes arrest in interphase. In such arrested cells the pattern of protein synthesis progresses as normal through the first cell cycle but does not show the characteristic changes that are associated with mitosis. Synthesis does occur of the 68/70 kd heat shock-like proteins, on the earliest detectable embryonic transcripts synthesised shortly after first cleavage in control embryos.

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