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"Raper, Anna"
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Human cytomegalovirus evades ZAP detection by suppressing CpG dinucleotides in the major immediate early 1 gene
by
Chiweshe, Stephen
,
Wilson, Sam J.
,
Simmonds, Peter
in
Alternative Splicing
,
Attenuation
,
Biology and life sciences
2020
The genomes of RNA and small DNA viruses of vertebrates display significant suppression of CpG dinucleotide frequencies. Artificially increasing dinucleotide frequencies results in substantial attenuation of virus replication, suggesting that these compositional changes may facilitate recognition of non-self RNA sequences. Recently, the interferon inducible protein ZAP, was identified as the host factor responsible for sensing CpG in viral RNA, through direct binding and possibly downstream targeting for degradation. Using an arrayed interferon stimulated gene expression library screen, we identified ZAPS, and its associated factor TRIM25, as inhibitors of human cytomegalovirus (HCMV) replication. Exogenous expression of ZAPS and TRIM25 significantly reduced virus replication while knockdown resulted in increased virus replication. HCMV displays a strikingly heterogeneous pattern of CpG representation with specific suppression of CpG motifs within the IE1 major immediate early transcript which is absent in subsequently expressed genes. We demonstrated that suppression of CpG dinucleotides in the IE1 gene allows evasion of inhibitory effects of ZAP. We show that acute virus replication is mutually exclusive with high levels of cellular ZAP, potentially explaining the higher levels of CpG in viral genes expressed subsequent to IE1 due to the loss of pressure from ZAP in infected cells. Finally, we show that TRIM25 regulates alternative splicing between the ZAP short and long isoforms during HCMV infection and interferon induction, with knockdown of TRIM25 resulting in decreased ZAPS and corresponding increased ZAPL expression. These results demonstrate for the first time that ZAP is a potent host restriction factor against large DNA viruses and that HCMV evades ZAP detection through suppression of CpG dinucleotides within the major immediate early 1 transcript. Furthermore, TRIM25 is required for efficient upregulation of the interferon inducible short isoform of ZAP through regulation of alternative splicing.
Journal Article
ADGRE1 (EMR1, F4/80) Is a Rapidly-Evolving Gene Expressed in Mammalian Monocyte-Macrophages
by
Bush, Stephen J.
,
Pridans, Clare
,
Clark, Emily L.
in
ADGRE1/EMR1
,
Alternative Splicing
,
Animals
2018
The F4/80 antigen, encoded by the
locus, has been widely-used as a monocyte-macrophage marker in mice, but its value as a macrophage marker in other species is unclear, and has even been questioned. ADGRE1 is a seven transmembrane G protein-coupled receptor with an extracellular domain containing repeated Epidermal Growth Factor (EGF)-like calcium binding domains. Using a new monoclonal antibody, we demonstrated that ADGRE1 is a myeloid differentiation marker in pigs, absent from progenitors in bone marrow, highly-expressed in mature granulocytes, monocytes, and tissue macrophages and induced by macrophage colony-stimulating factor (CSF1) treatment
. Based upon these observations, we utilized RNA-Seq to assess the expression of
mRNA in bone marrow or monocyte-derived macrophages (MDM) and alveolar macrophages from 8 mammalian species including pig, human, rat, sheep, goat, cow, water buffalo, and horse.
mRNA was expressed by macrophages in each species, with inter-species variation both in expression level and response to lipopolysaccharide (LPS) stimulation. Analysis of the RNA-Seq data also revealed additional exons in several species compared to current Ensembl annotations. The ruminant species and horses appear to encode a complete duplication of the 7 EGF-like domains. In every species, Sashimi plots revealed evidence of exon skipping of the EGF-like domains, which are highly-variable between species and polymorphic in humans. Consistent with these expression patterns, key elements of the promoter and a putative enhancer are also conserved across all species. The rapid evolution of this molecule and related ADGRE family members suggests immune selection and a role in pathogen recognition.
Journal Article
A stable NTN1 fluorescent reporter chicken reveals cell specific molecular signatures during optic fissure closure
2025
NTN1
is expressed in a wide range of developmental tissues and is essential for normal development. Here we describe the generation of a Netrin-1 reporter chicken line (
NTN1-T2A-eGFP
) by targeting green fluorescent protein into the
NTN1
locus using CRISPR/Cas9 methodology. Our strategy gave 100% transmission of heterozygous (
NTN1
T2A − eGFP
/+
) embryos in which GFP localisation faithfully replicated endogenous
NTN1
expression in the optic fissure and neural tube floorplate. Furthermore, all
NTN1
T2A − eGFP
/+
embryos and hatched birds appeared phenotypically normal. We applied this resource to a pertinent developmental context - coloboma is a structural eye malformation characterised by failure of epithelial fusion during optic fissure closure (OFC) and
NTN1
is specifically expressed in fusion pioneer cells at the edges of the optic fissure. We therefore optimised the isolation of GFP expressing cells from embryonic
NTN1
T2A − eGFP
/+
eyes using spectral fluorescence cell-sorting and applied transcriptomic profiling of pioneer cells, which revealed multiple new OFC markers and novel pathways for developmental tissue fusion and coloboma. This work provides a novel fluorescent
NTN1
chicken reporter line with broad experimental utility and is the first to directly molecularly characterise pioneer cells during OFC.
Journal Article
Protocol for a type 3 hybrid implementation cluster randomized clinical trial to evaluate the effect of patient and clinician nudges to advance the use of genomic medicine across a diverse health system
by
Ellis, Colin A.
,
Kripke, Colleen Morse
,
Oyer, Randall A.
in
Algorithms
,
Behavior
,
Behavioral economics
2024
Background
Germline genetic testing is recommended for an increasing number of conditions with underlying genetic etiologies, the results of which impact medical management. However, genetic testing is underutilized in clinics due to system, clinician, and patient level barriers. Behavioral economics provides a framework to create implementation strategies, such as nudges, to address these multi-level barriers and increase the uptake of genetic testing for conditions where the results impact medical management.
Methods
Patients meeting eligibility for germline genetic testing for a group of conditions will be identified using electronic phenotyping algorithms. A pragmatic, type 3 hybrid cluster randomization study will test nudges to patients and/or clinicians, or neither. Clinicians who receive nudges will be prompted to either refer their patient to genetics or order genetic testing themselves. We will use rapid cycle approaches informed by clinician and patient experiences, health equity, and behavioral economics to optimize these nudges before trial initiation. The primary implementation outcome is uptake of germline genetic testing for the pre-selected health conditions. Patient data collected through the electronic health record (e.g. demographics, geocoded address) will be examined as moderators of the effect of nudges.
Discussion
This study will be one of the first randomized trials to examine the effects of patient- and clinician-directed nudges informed by behavioral economics on uptake of genetic testing. The pragmatic design will facilitate a large and diverse patient sample, allow for the assessment of genetic testing uptake, and provide comparison of the effect of different nudge combinations. This trial also involves optimization of patient identification, test selection, ordering, and result reporting in an electronic health record-based infrastructure to further address clinician-level barriers to utilizing genomic medicine. The findings may help determine the impact of low-cost, sustainable implementation strategies that can be integrated into health care systems to improve the use of genomic medicine.
Trial registration
ClinicalTrials.gov. NCT06377033. Registered on March 31, 2024.
https://clinicaltrials.gov/study/NCT06377033?term=NCT06377033&rank=1
Journal Article
Phenotypic characterisation of bovine alveolar macrophages reveals two major subsets with differential expression of CD163
by
Burdon, Tom
,
Randall, Emily M.
,
Waddell, Lindsey A.
in
631/1647/1407/1492
,
631/250/2504/342
,
Alveoli
2024
Bovine alveolar macrophages (AMs) defend the lungs against pathogens such as
Mycobacterium bovis
(
M. bovis)
, the causative agent of bovine tuberculosis. However, little is known about the surface molecules expressed by bovine AMs and whether there is heterogeneity within the population. The purpose of this study was to characterise the bovine AM cell surface phenotype using flow cytometry. Bronchoalveolar lavage samples from four different calves were stained with a combination of antibodies against immune cell molecules prior to flow cytometric analysis. To assess the degree of expression, we considered the distribution and relative intensities of stained and unstained cells. We demonstrated that bovine AMs have high expression of CD172a, ADGRE1, CD206, and CD14, moderate expression of CD80, MHC II, CD1b, and CD40, low expression of CX3CR1 and CD86, and little or no expression of CD16 and CD26. Two distinct subsets of bovine AMs were identified based on CD163 expression. Subsequent analysis showed that the CD163
+
subset had greater expression of other typical macrophage molecules compared to the CD163
-
subset, suggesting that these cells may perform different roles during infection. The characterisation of the uninfected bovine AM phenotype will provide a foundation for the examination of
M. bovis-
infected AMs.
Journal Article
A genotype-first approach identifies high incidence of NF1 pathogenic variants with distinct disease associations
2025
Loss of function variants in the
NF1
gene cause neurofibromatosis type 1, a genetic disorder characterized by complete penetrance, characteristic physical exam findings, and a substantially increased risk for malignancy. However, our understanding of the disorder is based on patients ascertained through phenotype-first approaches, which estimate prevalence at 1 in 3000. Leveraging a genotype-first approach in multiple large patient cohorts including over one million individuals, we demonstrate an unexpectedly high prevalence (1 in 1,286) of
NF1
pathogenic variants. Half are identified in individuals lacking clinical features of NF1, with many appearing to have post-zygotic mosaicism for the identified variant. Incidentally discovered variants are not associated with classic neurofibromatosis features but are associated with an increased incidence of malignancy compared to control populations. Our findings suggest that
NF1
pathogenic variants are substantially more common than previously thought, often characterized by somatic mosaicism and reduced penetrance, and are important contributors to cancer risk in the general population.
Our current understanding of neurofibromatosis type 1 (NF1) is based on patients ascertained through phenotype-first approaches, which estimate a low prevalence at 1 in 3,000. Here, the authors leverage a genotype-first approach in multiple large patient cohorts to demonstrate an unexpectedly high prevalence (1 in 1,286) of
NF1
pathogenic variants with distinct disease associations.
Journal Article
Application across species of a one health approach to liquid sample handling for respiratory based -omics analysis
2021
Airway inflammation is highly prevalent in horses, with the majority of non-infectious cases being defined as equine asthma. Currently, cytological analysis of airway derived samples is the principal method of assessing lower airway inflammation. Samples can be obtained by tracheal wash (TW) or by lavage of the lower respiratory tract (bronchoalveolar lavage (BAL) fluid; BALF). Although BALF cytology carries significant diagnostic advantages over TW cytology for the diagnosis of equine asthma, sample acquisition is invasive, making it prohibitive for routine and sequential screening of airway health. However, recent technological advances in sample collection and processing have made it possible to determine whether a wider range of analyses might be applied to TW samples. Considering that TW samples are relatively simple to collect, minimally invasive and readily available in the horse, it was considered appropriate to investigate whether, equine tracheal secretions represent a rich source of cells and both transcriptomic and proteomic data. Similar approaches have already been applied to a comparable sample set in humans; namely, induced sputum. Sputum represents a readily available source of airway biofluids enriched in proteins, changes in the expression of which may reveal novel mechanisms in the pathogenesis of respiratory diseases, such as asthma and chronic obstructive pulmonary disease. The aim of this study was to establish a robust protocol to isolate macrophages, protein and RNA for molecular characterization of TW samples and demonstrate the applicability of sample handling to rodent and human pediatric bronchoalveolar lavage fluid isolates. TW samples provided a good quality and yield of both RNA and protein for downstream transcriptomic/proteomic analyses. The sample handling methodologies were successfully applicable to BALF for rodent and human research. TW samples represent a rich source of airway cells, and molecular analysis to facilitate and study airway inflammation, based on both transcriptomic and proteomic analysis. This study provides a necessary methodological platform for future transcriptomic and/or proteomic studies on equine lower respiratory tract secretions and BALF samples from humans and mice.
Journal Article
An Unusual Cause of Hexokinase 1 Deficiency—Case Report
by
Hartung, Helge
,
Conlin, Laura
,
Jadhav, Tanaya
in
Case Report
,
hereditary hemolytic anemia
,
non‐coding mutation
2025
Introduction Molecular analysis of red cell disorders has revolutionized diagnosis, however, there remain challenges. Main Symptoms This patient presented with hemolytic anemia in the newborn period. He required chronic transfusions to maintain his hemoglobin level until 6 years of age. A splenectomy was performed at 3 years of age. Main Diagnoses Using whole genome sequencing, we were able to identify a duplication upstream of the red cell promoter of HK1. Long‐read RNA sequencing established aberrant expression off of this promoter. Conclusions These non‐coding variants remain challenging to identify. His promoter duplication may have a founder effect in South Asia.
Journal Article
The fluorescent protein iLOV as a reporter for screening of high‐yield production of antimicrobial peptides in Pichia pastoris
by
Kjeldsen, Annemette
,
Baxter, Scott
,
Magneschi, Leonardo
in
Antiinfectives and antibacterials
,
Antimicrobial agents
,
Antimicrobial peptides
2022
Summary The methylotrophic yeast Pichia pastoris is commonly used for the production of recombinant proteins at scale. The identification of an optimally overexpressing strain following transformation can be time and reagent consuming. Fluorescent reporters like GFP have been used to assist identification of superior producers, but their relatively big size, maturation requirements and narrow temperature range restrict their applications. Here, we introduce the use of iLOV, a flavin‐based fluorescent protein, as a fluorescent marker to identify P. pastoris high‐yielding strains easily and rapidly. The use of this fluorescent protein as a fusion partner is exemplified by the production of the antimicrobial peptide NI01, a difficult target to overexpress in its native form. iLOV fluorescence correlated well with protein expression level and copy number of the chromosomally integrated gene. An easy and simple medium‐throughput plate‐based screen directly following transformation is demonstrated for low complexity screening, while a high‐throughput method using fluorescence‐activated cell sorting (FACS) allowed for comprehensive library screening. Both codon optimization of the iLOV_NI01 fusion cassettes and different integration strategies into the P. pastoris genome were tested to produce and isolate a high‐yielding strain. Checking the genetic stability, process reproducibility and following the purification of the active native peptide are eased by visualization of and efficient cleavage from the iLOV reporter. We show that this system can be used for expression and screening of several different antimicrobial peptides recombinantly produced in P. pastoris. The methylotrophic yeast Pichia pastoris is commonly used for production of recombinant proteins at scale, but identification of an optimally over‐expressing strain following transformation can be time and reagent consuming. Here we introduce the use of iLOV, a flavin based fluorescent protein, as a removable fluorescent marker to identify P. pastoris jackpot strains easily and rapidly. We show that this system can be used for expression, screening, and monitoring of genetic stability and process reproducibility of several different antimicrobial peptides recombinantly produced in Pichia.
Journal Article
Kagami Ogata syndrome: a small deletion refines critical region for imprinting
2024
Kagami–Ogata syndrome is a rare imprinting disorder and its phenotypic overlap with multiple different etiologies hampers diagnosis. Genetic etiologies include paternal uniparental isodisomy (upd(14)pat), maternal allele deletions of differentially methylated regions (DMR) in 14q32.2 or pure primary epimutations. We report a patient with Kagami–Ogata syndrome and an atypical diagnostic odyssey with several negative standard-of-care genetic tests followed by epigenetic testing using methylation microarray and a targeted analysis of whole-genome sequencing to reveal a 203 bp deletion involving the MEG3 transcript and MEG3:TSS-DMR. Long-read sequencing enabled the simultaneous detection of the deletion, phasing, and biallelic hypermethylation of the MEG3:TSS-DMR region in a single assay. This case highlights the challenges in the sequential genetic testing paradigm, the utility of long-read sequencing as a single comprehensive diagnostic assay, and the smallest reported deletion causing Kagami–Ogata syndrome allowing important insights into the mechanism of imprinting effects at this locus.
Journal Article