ORCID Profile
0000-0003-2146-8561
Current Organisations
University of Western Australia
,
Estonian University of Life Sciences
,
University of Oxford
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Publisher: Wiley
Date: 19-08-2020
DOI: 10.1111/BJH.16152
Publisher: Springer Science and Business Media LLC
Date: 19-08-2022
DOI: 10.1038/S41467-022-32567-8
Abstract: The biological determinants of the response to immune checkpoint blockade (ICB) in cancer remain incompletely understood. Little is known about dynamic biological events that underpin therapeutic efficacy due to the inability to frequently s le tumours in patients. Here, we map the transcriptional profiles of 144 responding and non-responding tumours within two mouse models at four time points during ICB. We find that responding tumours display on/fast-off kinetics of type-I-interferon (IFN) signaling. Phenocopying of this kinetics using time-dependent sequential dosing of recombinant IFNs and neutralizing antibodies markedly improves ICB efficacy, but only when IFNβ is targeted, not IFNα. We identify Ly6C + /CD11b + inflammatory monocytes as the primary source of IFNβ and find that active type-I-IFN signaling in tumour-infiltrating inflammatory monocytes is associated with T cell expansion in patients treated with ICB. Together, our results suggest that on/fast-off modulation of IFNβ signaling is critical to the therapeutic response to ICB, which can be exploited to drive clinical outcomes towards response.
Publisher: BMJ
Date: 06-2018
DOI: 10.1136/JCLINPATH-2018-205168
Abstract: The number of precursor and mature lymphoid cells and plasma cells in normal bone marrow trephine (BMT) biopsies throughout the human lifespan is unknown. Reference ranges have been established from aspirated marrow, but due to haemodilution errors, these do not accurately reflect the native marrow milieu. We aimed to define age-specific, normal reference ranges for lymphoid and plasma cells in BMT biopsy specimens using a combined immunophenotyping and digital enumeration approach. Morphologically normal BMT biopsy specimens (n=483) were obtained from patients aged 1 month to 90 years of age. Immunohistochemistry was performed to identify lymphoid progenitors , T-lymphocytes (CD3), B-lymphocytes (CD20) and plasma cells (CD138 and MUM1). Positive cells were counted using digital enumeration software, and the percent positivity for each antigen was determined per case. Mean values were generated for specific age groups, and age-defined reference ranges were determined for each antigen using normalised data. A mean of 16 609 cells (range: 7210–34 097) were counted per biopsy. Infant marrows showed a predominance of immature lymphoid progenitors and B cells. With increasing age, an increase in mean T cell and plasma cell numbers were observed. The results showed the same trends to flow cytometry references for aspirate material although the absolute values differed. Combined immunohistochemistry and automated enumeration gives an accurate, reproducible number of antigen-positive cells and has generated normal reference ranges for these cell types in BMT biopsies. The method and ranges we have established have the potential to be applied in routine clinical practice.
Publisher: Springer Science and Business Media LLC
Date: 02-06-2020
DOI: 10.1186/S13059-020-02048-6
Abstract: Single-cell RNA sequencing has been widely adopted to estimate the cellular composition of heterogeneous tissues and obtain transcriptional profiles of in idual cells. Multiple approaches for optimal s le dissociation and storage of single cells have been proposed as have single-nuclei profiling methods. What has been lacking is a systematic comparison of their relative biases and benefits. Here, we compare gene expression and cellular composition of single-cell suspensions prepared from adult mouse kidney using two tissue dissociation protocols. For each s le, we also compare fresh cells to cryopreserved and methanol-fixed cells. Lastly, we compare this single-cell data to that generated using three single-nucleus RNA sequencing workflows. Our data confirms prior reports that digestion on ice avoids the stress response observed with 37 °C dissociation. It also reveals cell types more abundant either in the cold or warm dissociations that may represent populations that require gentler or harsher conditions to be released intact. For cell storage, cryopreservation of dissociated cells results in a major loss of epithelial cell types in contrast, methanol fixation maintains the cellular composition but suffers from ambient RNA leakage. Finally, cell type composition differences are observed between single-cell and single-nucleus RNA sequencing libraries. In particular, we note an underrepresentation of T, B, and NK lymphocytes in the single-nucleus libraries. Systematic comparison of recovered cell types and their transcriptional profiles across the workflows has highlighted protocol-specific biases and thus enables researchers starting single-cell experiments to make an informed choice.
Publisher: American Society of Hematology
Date: 03-03-2022
Abstract: RNA processing is increasingly recognized as a critical control point in the regulation of different hematopoietic lineages including megakaryocytes responsible for the production of platelets. Platelets are anucleate cytoplasts that contain a rich repertoire of RNAs encoding proteins with essential platelet functions derived from the parent megakaryocyte. It is largely unknown how RNA binding proteins contribute to the development and functions of megakaryocytes and platelets. We show that serine-arginine–rich splicing factor 3 (SRSF3) is essential for megakaryocyte maturation and generation of functional platelets. Megakaryocyte-specific deletion of Srsf3 in mice led to macrothrombocytopenia characterized by megakaryocyte maturation arrest, dramatically reduced platelet counts, and abnormally large functionally compromised platelets. SRSF3 deficient megakaryocytes failed to reprogram their transcriptome during maturation and to load platelets with RNAs required for normal platelet function. SRSF3 depletion led to nuclear accumulation of megakaryocyte mRNAs, demonstrating that SRSF3 deploys similar RNA regulatory mechanisms in megakaryocytes as in other cell types. Our study further suggests that SRSF3 plays a role in sorting cytoplasmic megakaryocyte RNAs into platelets and demonstrates how SRSF3-mediated RNA processing forms a central part of megakaryocyte gene regulation. Understanding SRSF3 functions in megakaryocytes and platelets provides key insights into normal thrombopoiesis and platelet pathologies as SRSF3 RNA targets in megakaryocytes are associated with platelet diseases.
Publisher: Frontiers Media SA
Date: 2012
Publisher: American Society for Microbiology
Date: 03-2014
DOI: 10.1128/JVI.02720-13
Abstract: Prion diseases are a group of fatal and incurable neurodegenerative diseases affecting both humans and animals. The principal mechanism of these diseases involves the misfolding the host-encoded cellular prion protein, PrP C , into the disease-associated isoform, PrP Sc . Familial forms of human prion disease include those associated with the mutations G114V and A117V, which lie in the hydrophobic domain of PrP. Here we have studied the murine homologues (G113V and A116V) of these mutations using cell-based and animal models of prion infection. Under normal circumstances, the mutant forms of PrP C share similar processing, cellular localization, and physicochemical properties with wild-type mouse PrP (MoPrP). However, upon exposure of susceptible cell lines expressing these mutants to infectious prions, very low levels of protease-resistant aggregated PrP Sc are formed. Subsequent mouse bioassay revealed high levels of infectivity present in these cells. Thus, these mutations appear to limit the formation of aggregated PrP Sc , giving rise to the accumulation of a relatively soluble, protease sensitive, prion species that is highly neurotoxic. Given that these mutations lie next to the glycine-rich region of PrP that can abrogate prion infection, these findings provide further support for small, protease-sensitive prion species having a significant role in the progression of prion disease and that the hydrophobic domain is an important determinant of PrP conversion. IMPORTANCE Prion diseases are transmissible neurodegenerative diseases associated with an infectious agent called a prion. Prions are comprised of an abnormally folded form of the prion protein (PrP) that is normally resistant to enzymes called proteases. In humans, prion disease can occur in in iduals who inherited mutations in the prion protein gene. Here we have studied the effects of two of these mutations and show that they influence the properties of the prions that can be formed. We show that the mutants make highly infectious prions that are more sensitive to protease treatment. This study highlights a certain region of the prion protein as being involved in this effect and demonstrates that prions are not always resistant to protease treatment.
Publisher: Elsevier BV
Date: 02-2015
Publisher: BMJ
Date: 08-04-2016
Publisher: Research Square Platform LLC
Date: 24-09-2021
DOI: 10.21203/RS.3.RS-892399/V1
Abstract: Little is known about the dynamic biological events that underpin therapeutic efficacy in immune checkpoint blockade (ICB) in cancer, due to the inability to frequently s le tumors in patients. Here, we mapped the transcriptional profiles of 144 responding and non-responding tumors within two mouse models at four time points during ICB. We found that responding tumors displayed on/fast-off kinetics of type-I-interferon (IFN) signaling. Phenocopying of this kinetics using time-dependent sequential dosing of recombinant IFNs and neutralizing anti-bodies markedly improved ICB efficacy, but only when IFNβ was targeted, not IFNα. We identified Ly6C+/CD11b+ inflammatory monocytes as the primary source of IFNβ and found that active type-I-IFN signaling in tumor-infiltrating inflammatory monocytes was associated with T cell expansion in patients treated with ICB. Together, our results suggest that on/fast-off modulation of IFNβ signaling is critical to the therapeutic response to ICB, which can be exploited to drive clinical outcomes towards response.
Publisher: Elsevier BV
Date: 03-2016
Publisher: Informa UK Limited
Date: 07-06-2018
Publisher: Cold Spring Harbor Laboratory
Date: 06-11-2019
DOI: 10.1101/832444
Abstract: Single-cell and single-nucleus RNA sequencing have been widely adopted in studies of heterogeneous tissues to estimate their cellular composition and obtain transcriptional profiles of in idual cells. However, the current fragmentary understanding of artefacts introduced by s le preparation protocols impedes the selection of optimal workflows and compromises data interpretation. To bridge this gap, we compared performance of several workflows applied to adult mouse kidneys. Our study encompasses two tissue dissociation protocols, two cell preservation methods, bulk tissue RNA sequencing, single-cell and three single-nucleus RNA sequencing workflows for the 10x Genomics Chromium platform. These experiments enable a systematic comparison of recovered cell types and their transcriptional profiles across the workflows and highlight protocol-specific biases important for the experimental design and data interpretation.
Publisher: Elsevier BV
Date: 07-2017
Publisher: American Society of Agricultural and Biological Engineers
Date: 2020
Publisher: BMJ
Date: 19-08-2016
DOI: 10.1136/JCLINPATH-2015-203177
Abstract: Myeloproliferative neoplasms (MPN) are a heterogeneous group of clonal proliferative bone marrow diseases characterised by extensive megakaryocytic hyperplasia and morphological atypia. Despite knowledge of genomic defects, the pathobiological processes driving these megakaryocytic abnormalities in MPN remain poorly explained. We have explored the proliferative, apoptotic and epigenetic profiles of megakaryocytes in human MPN. Immunohistochemical staining was performed on bone marrow trephine biopsies of 81 MPN (with and without JAK2(V617F) and CALR mutations) and 15 normal controls to assess the megakaryocytic expression of biomarkers associated with proliferation (Ki67), apoptosis (Bcl-XL, BNIP-3) and epigenetic regulation (EZH2, SUZ12). Myeloproliferative megakaryocytes showed significantly greater expression of proliferative Ki67 and anti-apoptotic Bcl-XL, reduced pro-apoptotic BNIP-3 and increased SUZ12 compared with controls. In essential thrombocythaemia, large-giant megakaryocytes with hyperlobated nuclei showed a trend towards a proliferative signature. In contrast, myelofibrotic megakaryocytes with condensed nuclear chromatin, and cases with CALR mutations, had significant reductions in pro-apoptotic BNIP-3. Uncontrolled megakaryocytic expansion in MPN results from a combination of increased proliferation, attenuated apoptosis and defective epigenetic regulation with CALR mutations favouring apoptotic failure. The higher platelet counts reported to be seen in MPN with CALR mutations may be due to greater dysregulation of megakaryocyte apoptosis.
Publisher: Elsevier BV
Date: 04-2021
Publisher: Elsevier BV
Date: 03-2009
DOI: 10.1016/J.BBRC.2009.01.169
Abstract: Dihydrodipicolinate synthase (DHDPS) catalyses the first committed step in the biosynthesis of (S)-lysine, an essential constituent of bacterial cell walls. Escherichia coli DHDPS is homotetrameric, and each monomer contains an N-terminal (alpha/beta)(8)-barrel, responsible for catalysis and regulation, and three C-terminal alpha-helices, the function of which is unknown. This study investigated the C-terminal domain of E. coli DHDPS by characterising a C-terminal truncated DHDPS (DHDPS-H225*). DHDPS-H225* was unable to complement an (S)-lysine auxotroph, and showed significantly reduced solubility, stability, and maximum catalytic activity (k(cat)=1.20+/-0.01 s(-1)), which was only 1.6% of wild type E. coli DHDPS (DHDPS-WT). The affinity of DHDPS-H225* for substrates and the feedback inhibitor, (S)-lysine, remained comparable to DHDPS-WT. These changes were accompanied by disruption in the quaternary structure, which has previously been shown to be essential for efficient catalysis in this enzyme.
Publisher: Elsevier BV
Date: 2014
Publisher: Wiley
Date: 24-06-2015
Abstract: Biologically active metals such as copper, zinc and iron are fundamental for sustaining life in different organisms with the regulation of cellular metal homeostasis tightly controlled through proteins that coordinate metal uptake, efflux and detoxification. Many of the proteins involved in either uptake or efflux of metals are localised and function on the plasma membrane, traffic between intracellular compartments depending upon the cellular metal environment and can undergo recycling via the endosomal pathway. The biogenesis of exosomes also occurs within the endosomal system, with several major neurodegenerative disease proteins shown to be released in association with these vesicles, including the amyloid-β (Aβ) peptide in Alzheimer's disease and the infectious prion protein involved in Prion diseases. Aβ peptide and the prion protein also bind biologically active metals and are postulated to play important roles in metal homeostasis. In this review, we will discuss the role of extracellular vesicles in Alzheimer's and Prion diseases and explore their potential contribution to metal homeostasis.
Publisher: Wiley
Date: 06-10-2022
DOI: 10.1002/CNR2.1573
Abstract: Acute myeloid leukaemia (AML) results from the clonal expansion of blast cells of myeloid origin driven by genomic defects. The advances in next‐generation sequencing (NGS) have allowed the identification of many mutated genes important in the pathogenesis of AML. In this study, we aimed to assess the mutation types and frequency in a Chinese cohort presenting with de novo AML cohort using a targeted NGS strategy. In total, we studied s les from 87 adult patients with de novo AML who had no prior history of cytotoxic chemotherapy. S les were evaluated using a 120‐gene targeted NGS panel to assess the mutation profile. Of the 87 AML patients, there were 60 (69%) with a normal karyotype. 89.7% of patients had variants, with an average of 1.9 mutations per patient (range: 0–5 mutations per patient). DNMT3A variants were the most common, being detected in 33 patients (37.9%). NPM1 (34.5%), IDH1/2 (24.1%) and FLT3‐ITD (20.7%) mutations was the next most common. Of the patients with DNMT3A mutations, 24.2% also had mutations NPM1 and FLT3‐ITD and 6.1% NPM1 , FLT3‐ITD and IDH mutations. Both DNMT3A and NPM1 mutations were more common than in other Chinese and Western AML cohorts that have been studied. DNMT3A mutations tended to co‐occur with NPM1 and FLT3‐ITD mutations and were most commonly seen with a normal karyotype.
Publisher: Wiley
Date: 06-01-2021
DOI: 10.1002/PATH.5592
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 26-10-2020
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Belinda Guo.