ORCID Profile
0000-0002-0506-6389
Current Organisations
University of Tasmania
,
Tasmanian Department of Education
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Publisher: MDPI AG
Date: 13-01-2021
DOI: 10.3390/MOLECULES26020387
Abstract: Sparkling wine made by the traditional method (Méthode Traditionelle) develops a distinct and desirable flavour and aroma profile attributed to proteolytic processes during prolonged ageing on lees. Microwave, ultrasound and addition of β-glucanase enzymes were applied to accelerate the disruption of Saccharomyces cerevisiae, and added to the tirage solution for secondary fermentation in traditional sparkling winemaking. Scanning electron microscopy and flow cytometry analyses were used to observe and describe yeast whole-cell anatomy, and cell integrity and structure via propidium iodide (PI) permeability after 6-, 12- and 18-months post-tirage. Treatments applied produced features on lees that were distinct from that of the untreated control yeast. Whilst control yeast displayed budding cells (growth features) with smooth, cavitated and flat external cell appearances microwave treated yeast cells exhibited modifications like ‘doughnut’ shapes immediately after treatment (time 0). Similar ‘doughnut’-shaped and ‘pitted orous’ cell features were observed on progressively older lees from the control. Flow cytometry was used to discriminate yeast populations features consistent with cell disruption were observed in the microwave, ultrasound and enzyme treatments, as evidenced by up to 4-fold increase in PI signal in the microwave treatment. Forward and side scatter signals reflected changes in size and structure of yeast cells, in all treatments applied. When flow cytometry was interpreted alongside the scanning electron microscopy images, bimodal populations of yeast cells with low and high PI intensities were revealed and distinctive ‘doughnut’-shaped cell features observed in association with the microwave treatment only at tirage, that were not observed until 12 months wine ageing in older lees from the control. This work offers both a rapid approach to visualise alterations to yeast cell surfaces and a better understanding of the mechanisms of yeast lysis. Microwave, ultrasound or β-glucanase enzymes are tools that could potentially initiate the release of yeast cell compounds into wine. Further investigation into the impact of such treatments on the flavour and aroma profiles of the wines through sensory evaluation is warranted.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 03-07-2020
Abstract: A simple cut-and-paste reagent development method applicable to any species reveals checkpoint molecules on transmissible cancers.
Publisher: American Society for Microbiology
Date: 15-07-2010
DOI: 10.1128/AEM.00315-10
Abstract: In an experiment delineating aciduric strains, food and clinical Listeria monocytogenes isolates tended to produce the most biomass whereas ovine and avian strains produced comparatively less biomass when exposed to high levels of sodium diacetate (SD) and potassium sorbate. Compared to reference strains that exhibited greater acid sensitivity, representative food isolates with comparatively good growth capacities in the presence of 21 mM SD at pH 5.0 accumulated reduced levels of acetate anion and K + ion. The aciduric nature of SD-resistant strains was also reflected by comparatively high tolerance to pH 2.4 (HCl) acid challenges, a property boosted by the presence of SD. Exposure to elevated levels of SD (21 mM SD at pH 5.0) was found to have broad effects on gene expression, as differentiated from effects caused by mildly acidic conditions (pH 5.0). SD-resistant strain FW04/0025 was more responsive to elevated SD, increasing the expression of 222 genes ( -fold change [ P 0.05]), compared to the more sensitive EGD reference strain, which exhibited increases in expression of 112 genes. Key differences between the strains in relation to SD-enhanced transcripts were notably associated with the cell envelope, oxidative stress management, and intermediary metabolism. SD thus appears to differentially influence growth efficiency and survival of strains, under conditions relevant to acidic foods, that could be due to altered cell wall and metabolic phenotypes.
Publisher: MDPI AG
Date: 10-02-2020
Abstract: Background: The immune-modulator behaviour of the CCR6/CCL20 axis in multi -system pathophysiology and molecular signalling was investigated at two clinically significant time points, using a Ccr6—deficient mouse model of spontaneous colitis. Methods:Four groups of mice, (C57BL/6J, Ccr6−/− of C57BL/6J, Winnie × Ccr6−/− and Winnie) were utilized and (I) colonic clinical parameters (2) histology of colon, spleen, kidney and liver (3) T and B lymphocyte distribution in the spleen and MLN by flowcytometry (5) colonic CCL20, phosphorylated PI3K and phosphorylated Akt expression by immunohistochemistry and (6) colonic cytokine expression by RT-PCR were evaluated. Results: CCR6 deficiency was shown to attenuate inflammation in the spleen, liver and gut while renal histology remained unaffected. Marked focal lobular inflammation with reactive nuclear features were observed in hepatocytes and a significant neutrophil infiltration in red pulp with extra medullary hemopoiesis in the spleen existed in Winnie. These changes were considerably reduced in Winnie × Ccr6−/− with elevated goblet cell numbers and mucus production in the colonic epithelium. Conclusions: Results indicate that Ccr6-deficiency in the colitis model contributes towards resolution of disease. Our findings demonstrate an intricate networking role for CCR6 in immune activation, which is downregulated by Ccr6 deficiency, and could provide newer clinical therapies in colitis.
Publisher: Wiley
Date: 06-2022
Publisher: Cold Spring Harbor Laboratory
Date: 07-11-2020
DOI: 10.1101/831404
Abstract: Immune checkpoint immunotherapy has revolutionized medicine, but translational success for new treatments remains low. Around 40% of humans and Tasmanian devils ( Sarcophilus harrisii ) develop cancer in their lifetime, compared to less than 10% for most species. Additionally, devils are affected by two of the three known transmissible cancers in mammals. Unfortunately, little is known about of immune checkpoints in devils and other non-model species, largely due to a lack of species-specific reagents. We developed a simple cut-and-paste reagent development method applicable to any vertebrate species and show that immune checkpoint interactions are conserved across 160 million years of evolution. The inhibitory checkpoint molecule CD200 is highly expressed on devil facial tumor cells. We are the first to demonstrate that co-expression of CD200R1 can block CD200 expression. The evolutionarily conserved pathways suggest that naturally occurring cancers in devils and other species can serve as models for understanding cancer and immunological tolerance.
Publisher: Frontiers Media SA
Date: 27-05-2014
Publisher: Elsevier BV
Date: 02-2021
DOI: 10.1016/J.DCI.2020.103882
Abstract: Immune checkpoint immunotherapy is a pillar of human oncology treatment with potential for non-human species. The first checkpoint immunotherapy approved for human cancers targeted the CTLA4 protein. CTLA4 can inhibit T cell activation by capturing and internalizing CD80 and CD86 from antigen presenting cells, a process called trans-endocytosis. Similarly, CD28 can capture CD80 and CD86 via trogocytosis and retain the captured ligands on the surface of the CD28-expressing cells. The wild Tasmanian devil (Sarcophilus harrisii) population has declined by 77% due to transmissible cancers that evade immune defenses despite genetic mismatches between the host and tumors. We used a live cell-based assay to demonstrate that devil CTLA4 and CD28 can capture CD80 and CD86. Mutation of evolutionarily conserved motifs in CTLA4 altered functional interactions with CD80 and CD86 in accordance with patterns observed in other species. These results suggest that checkpoint immunotherapies can be translated to evolutionarily ergent species.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Springer Science and Business Media LLC
Date: 16-10-2019
DOI: 10.1007/S00442-019-04530-W
Abstract: Telomere dynamics vary fundamentally between endothermic populations and species as a result of differences in life history, yet we know little about these patterns in ectotherms. In ectotherms, the relationships between climate, metabolism and life history suggest that telomere attrition should be higher at relatively high environmental temperatures compared to relatively low environmental temperatures, but these effects may vary between populations due to local adaptation. To address this hypothesis, we s led reactive oxygen species (ROS) and telomere length of lizards from warm lowland and cool highland populations of a climatically widespread lizard species that we exposed to hot or cold basking treatments. The hot treatment increased relative telomere length compared to the cold treatment independent of climatic origin or ROS levels. Lizards from the cool highland region had lower ROS levels than those from the warm lowland region. Within the highland lizards, ROS increased more in the cold basking treatment than the hot basking treatment. These results are in the opposite direction to those predicted, suggesting that the relationships between temperature, metabolism, ROS and telomere dynamics are not straightforward. Future work incorporating detailed understanding of the thermal reaction norms of these and other linked traits is needed to fully understand these processes.
Publisher: Wiley
Date: 2013
DOI: 10.1111/IZY.12014
Publisher: American Association for Cancer Research (AACR)
Date: 31-10-2016
DOI: 10.1158/2326-6066.IMM2016-B040
Abstract: Background: The potent immune modifier imiquimod (R-837) induces apoptosis of various tumor cell lines by mechanisms that are not fully understood. As a topical immunotherapy, imiquimod successfully activates tumor-specific cytotoxic responses via stimulation of TLR7 signaling pathways and antagonism of adenosine receptor mediated regulatory pathways. A role for imiquimod-induced tumor apoptosis in augmenting this response has not been defined, however it remains plausible that molecular changes may render the cells more susceptible to an anti-tumor response. An improved understanding of the pathways regulated by imiquimod in tumor cells will reveal whether this is likely the case. Devil facial tumor disease (DFTD) is a clonal transmissible cancer threatening the world's largest marsupial carnivore, the Tasmanian devil. DFTD evades both non-self and anti-cancer immune defenses to survive in new hosts, providing an ideal model for studying immunotherapeutic mechanisms. As we have previously shown that DFTD cells are sensitive to treatment with imiquimod, investigation of these effects could reveal new therapeutic strategies for DFTD, and will improve our understanding of this drug in cancer immunotherapy. Methods: To investigate the mechanisms of imiquimod action in tumor cells, DFTD cell lines and control fibroblast cell lines were treated in culture with imiquimod. Changes to cell viability were monitored by proliferation and cell death assays. Molecular changes to DFTD cells were assessed through RNA sequencing and proteomic mass spectrometry, and bioinfomatic techniques were employed to identify biological processes regulated by imiquimod. Major findings were confirmed by quantitative PCR. Results: Imiquimod treatment induces complete apoptosis of DFTD cells, but not fibroblasts, over a period of days. Transcriptomic and proteomic analysis revealed high constitutive expression of ER stress genes in DFTD cell lines, which were further augmented in response to imiquimod treatment. Up-regulation of genes required for ER-stress mediated apoptosis was also detected, suggesting that imiquimod induces apoptosis through exhaustion of the ER stress response. Molecular pathways associated with tumor growth and survival were modulated in the dying cells, and damage-associated alarmins were highly expressed. Conclusions: Our study provides the first whole transcriptome and proteome analysis of any imiquimod treated tumor cell line. By using DFTD cells as a tumor model, we have shown that imiquimod directly increases the apoptotic potential of tumor cells through augmentation of ER stress, while producing molecular changes consistent with reduced tumorigenicity. These effects were not replicated in fibroblasts, suggesting that constitutive activation of stress responses in tumor cells may impact their ability to cope with additional stressors. Our findings suggest that ER stress pathways are ideal targets for therapy against DFTD in our endangered Tasmanian devil. These data can also be applied for more rational use of imiquimod as an immunotherapeutic agent in human cancer. Citation Format: Amanda L. Patchett, Terry L. Pinfold, Cesar Tovar, Bruce Lyons, Gregory M. Woods. Imiquimod initiates tumor specific overload of the ER stress response in Tasmanian devil facial cancer cells [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival 2016 Sept 25-28 New York, NY. Philadelphia (PA): AACR Cancer Immunol Res 2016 (11 Suppl):Abstract nr B040.
Publisher: Bio-Protocol, LLC
Date: 2020
No related grants have been discovered for Terry Pinfold.