ORCID Profile
0000-0002-7921-2326
Current Organisations
Monash University
,
University of Oxford
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Publisher: Elsevier BV
Date: 12-2015
Publisher: Elsevier BV
Date: 04-2008
Abstract: Experimental unilateral ureteral obstruction (UUO) is widely used to study renal fibrosis however, renal injury can only be scored semiobjectively by histology. We sought to improve the UUO model by reimplanting the obstructed ureter followed by removal of the contralateral kidney, thus allowing longitudinal measurements of renal function. Mice underwent UUO for different lengths of time before ureteral reimplantation and contralateral nephrectomy. Measurement of blood urea nitrogen (BUN) allows objective evaluation of residual renal function. Seven weeks after reimplantation and contralateral nephrectomy, mean BUN levels were increased with longer duration of UUO. Interstitial expansion, fibrosis, and T-cell and macrophage infiltration were similar in kidneys harvested after 10 days of UUO or following 10 weeks of ureter reimplantation, suggesting that the inflammatory process persisted despite relief of obstruction. Urinary protein excretion after reimplantation was significantly increased compared to control animals. Our study shows that functional assessment of the formerly obstructed kidney can be made after reimplantation and may provide a useful model to test therapeutic strategies for reversing renal fibrosis and preserving or restoring renal function.
Publisher: Springer Science and Business Media LLC
Date: 24-03-2020
DOI: 10.1038/S41598-020-62492-Z
Abstract: An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Publisher: Springer Science and Business Media LLC
Date: 07-01-2020
DOI: 10.1186/S12916-019-1470-Y
Abstract: Endometriosis is a gynaecological condition characterised by immune cell infiltration and distinct inflammatory signatures found in the peritoneal cavity. In this study, we aim to characterise the immune microenvironment in s les isolated from the peritoneal cavity in patients with endometriosis. We applied mass cytometry (CyTOF), a recently developed multiparameter single-cell technique, in order to characterise and quantify the immune cells found in peritoneal fluid and peripheral blood from endometriosis and control patients. Our results demonstrate the presence of more than 40 different distinct immune cell types within the peritoneal cavity. This suggests that there is a complex and highly heterogeneous inflammatory microenvironment underpinning the pathology of endometriosis. Stratification by clinical disease stages reveals a dynamic spectrum of cell signatures suggesting that adaptations in the inflammatory system occur due to the severity of the disease. Notably, among the inflammatory microenvironment in peritoneal fluid (PF), the presence of CD69 + T cell subsets is increased in endometriosis when compared to control patient s les. On these CD69 + cells, the expression of markers associated with T cell function are reduced in PF s les compared to blood. Comparisons between CD69 + and CD69 − populations reveal distinct phenotypes across peritoneal T cell lineages. Taken together, our results suggest that both the innate and the adaptive immune system play roles in endometriosis. This study provides a systematic characterisation of the specific immune environment in the peritoneal cavity and identifies cell immune signatures associated with endometriosis. Overall, our results provide novel insights into the specific cell phenotypes governing inflammation in patients with endometriosis. This prospective study offers a useful resource for understanding disease pathology and opportunities for identifying therapeutic targets.
Publisher: Frontiers Media SA
Date: 26-10-2021
Abstract: Uterine Fibroids (leiomyomata) and endometriosis affect millions of women world-wide. Although aetiology and natural history of the conditions are markedly different, symptoms can overlap and make differential diagnoses necessary, often using invasive methods such as laparoscopy. Considerable comorbidity exists between the two conditions and needs to be taken into account when treating fibroids and/or endometriosis. The genetic foundations of both uterine fibroids and endometriosis remain to be fully understood but recent evidence suggest common underpinnings. Here, we discuss the comorbidity of uterine fibroids and endometriosis and the implications for diagnosis, treatment and risks.
Publisher: EMBO
Date: 23-01-2004
Abstract: Toll‐like receptors (TLRs) mediate recognition of microbial components. Despite activation of a shared set of signal transduction molecules, the biological effects of certain TLR agonists differ considerably. In macrophages and dendritic cells, stimulation by the prototypical stimuli CpG‐DNA (TLR9), lipopolysaccharide (LPS TLR4) and lipoteichoic acid (LTA TLR2) resulted in striking differences in expression of IL‐12. However, these stimuli induced similar amounts of the common proinflammatory cytokine TNFα. Surprisingly, an IL‐12p40 promoter reporter construct was activated equally by CpG‐DNA, LPS and LTA. Examinations of the chromatin structure of the endogenous IL‐12p40 promoter revealed that nucleosome remodelling contributed to differential IL‐12 induction. Upon stimulation, nucleosome architecture was changed to provide increased access to the IL‐12p40 promoter. In dendritic cells, a differential induction of nucleosome remodelling at the IL‐12p40 promoter was observed upon triggering with different TLR agonists. These results identify nucleosome remodelling as an additional restriction point in differential TLR signalling.
Publisher: Informa UK Limited
Date: 03-10-2017
Publisher: Oxford University Press (OUP)
Date: 24-10-2023
Publisher: Elsevier BV
Date: 08-2010
DOI: 10.1038/KI.2010.177
Abstract: Tubulointerstitial fibrosis is a common consequence of a erse range of kidney diseases that lead to end-stage renal failure. The degree of fibrosis is related to leukocyte infiltration. Here, we determined the role of different T cell populations on renal fibrosis in the well-characterized mouse model of unilateral ureteric obstruction. Depletion of CD4(+) T cells in wild-type mice with a monoclonal antibody significantly reduced the amount of interstitial expansion and collagen deposition after 2 weeks of obstruction. Reconstitution of lymphopenic RAG knockout mice with purified CD4(+) but not CD8(+) T cells, prior to ureteric obstruction, resulted in a significant increase in interstitial expansion and collagen deposition. Wild-type mice had significantly greater interstitial expansion and collagen deposition compared with lymphopenic RAG(-/-) mice, following ureteric obstruction however, macrophage infiltration was equivalent in all groups. Thus, our results suggest that renal injury with subsequent fibrosis is likely to be a multifactorial process, with different arms of the immune system involved at different stages. In this ureteric obstruction model, we found a critical role for CD4(+) T cells in kidney fibrosis. These cells could be a potential target of therapeutic intervention to prevent excessive fibrosis and loss of function due to renal injury.
Publisher: Springer International Publishing
Date: 2014
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-01-2013
DOI: 10.1002/HEP.26094
Abstract: Liver metastasis from colorectal cancer is a leading cause of cancer mortality. Myeloid cells play pivotal roles in the metastatic process, but their prometastatic functions in liver metastasis remain incompletely understood. To investigate their role, we simulated liver metastasis in C57BL/6 mice through intrasplenic inoculation of MC38 colon carcinoma cells. Among the heterogeneous myeloid infiltrate, we identified a distinct population of CD11b/Gr1(mid) cells different from other myeloid populations previously associated with liver metastasis. These cells increased in number dramatically during establishment of liver metastases and were recruited from bone marrow by tumor-derived CCL2. Liver metastasis of Lewis lung carcinoma cells followed this pattern but this mechanism is not universal as liver colonization by B16F1 melanoma cells did not recruit similar subsets. Inhibition of CCL2 signaling and absence of its cognate receptor CCR2 reduced CD11b/Gr1(mid) recruitment and decreased tumor burden. Depletion of the CD11b/Gr1(mid) subset in a transgenic CD11b-diphtheria toxin receptor mouse model markedly reduced tumor cell proliferation. There was no evidence for involvement of an adaptive immune response in the prometastatic effects of CD11b/Gr1(mid) cells. Additionally, an analogous myeloid subset was found in liver metastases of some colorectal cancer patients. Collectively, our findings highlight the importance of myeloid cells--in this case a selective CD11b/Gr1(mid) subset--in sustaining development of colorectal cancer liver metastasis and identify a potential target for antimetastatic therapy.
Publisher: Proceedings of the National Academy of Sciences
Date: 20-07-2015
Abstract: Acidic pH may distinguish aggressive from more indolent cancers. The limitation on testing this hypothesis to date has been the difficulty of measuring acidic pH in cancers. Here we show that retention of the pH low insertion peptide (pHLIP) Variant 3 (Var3) reflects acidic pH. Using pHLIP Var3, we show its ability to detect cancer with a low false-positive rate in a genetically engineered model of murine breast cancer, paving the way for testing this probe in clinical situations.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 25-08-2021
DOI: 10.1126/SCITRANSLMED.ABD6469
Abstract: Genetic analyses in humans and macaques followed by cellular and mouse studies demonstrate NPSR1 as a nonhormonal drug target in endometriosis.
Publisher: MDPI AG
Date: 17-02-2018
DOI: 10.3390/IJMS19020599
Publisher: Elsevier BV
Date: 02-2020
Publisher: Springer Science and Business Media LLC
Date: 14-10-2022
DOI: 10.1038/S41388-022-02488-3
Abstract: Metastatic tumour progression is facilitated by tumour associated macrophages (TAMs) that enforce pro-tumour mechanisms and suppress immunity. In pulmonary metastases, it is unclear whether TAMs comprise tissue resident or infiltrating, recruited macrophages and the different expression patterns of these TAMs are not well established. Using the mouse melanoma B16F10 model of experimental pulmonary metastasis, we show that infiltrating macrophages (IM) change their gene expression from an early pro-inflammatory to a later tumour promoting profile as the lesions grow. In contrast, resident alveolar macrophages (AM) maintain expression of crucial pro-inflammatory/anti-tumour genes with time. During metastatic growth, the pool of macrophages, which initially contains mainly alveolar macrophages, increasingly consists of infiltrating macrophages potentially facilitating metastasis progression. Blocking chemokine receptor mediated macrophage infiltration in the lung revealed a prominent role for CCR2 in Ly6C + pro-inflammatory monocyte/macrophage recruitment during metastasis progression, while inhibition of CCR2 signalling led to increased metastatic colony burden. CCR1 blockade, in contrast, suppressed late phase pro-tumour MR + Ly6C - monocyte/macrophage infiltration accompanied by expansion of the alveolar macrophage compartment and accumulation of NK cells, leading to reduced metastatic burden. These data indicate that IM has greater plasticity and higher phenotypic responsiveness to tumour challenge than AM. A considerable difference is also confirmed between CCR1 and CCR2 with regard to the recruited IM subsets, with CCR1 presenting a potential therapeutic target in pulmonary metastasis from melanoma.
Publisher: The American Association of Immunologists
Date: 15-03-2008
DOI: 10.4049/JIMMUNOL.180.6.3910
Abstract: Homeostatic proliferation is a normal physiological process triggered by lymphopenia to maintain a constant level of T cells. It becomes the predominant source of new T cells in adulthood after thymus regression. T cells that have undergone homeostatic proliferation acquire the memory phenotype, cause autoimmune disease, and are resistant to tolerance induction protocols. Transplantation is a rare ex le in which lymphopenia is deliberately induced for its immunosuppressive effect. However, it is not known whether the homeostatic proliferation that follows will have the opposite effect and accelerate rejection. We show that T cells that have undergone homeostatic proliferation acquire a memory phenotype, spontaneously skews toward the Th1 phenotype, even in the absence of antigenic stimulus. Interestingly, in contrast, the percentage of Foxp3+ regulatory T cells increased by 28-fold following homeostatic proliferation. Using a mouse life-sustaining kidney transplant model, we showed that T cells that have gone through homeostatic proliferation in lymphopenic hosts transformed chronic rejection to acute rejection of a single MHC class II-mismatched kidney allograft. T cells that have undergone homeostatic proliferation consistently cause reliable rejection even when bona fide memory T cells cannot. These functional changes are long-lasting and not restricted to the acute phase of homeostatic proliferation. Our findings have important implications for tolerance induction or graft-prolonging protocols involving leukocyte depletion such as irradiation bone marrow chimera, T cell-depleting Abs, and lymphopenia induced by infections such as CMV and HIV.
Publisher: Informa UK Limited
Date: 03-2013
DOI: 10.4161/ONCI.23187
Publisher: Wiley
Date: 03-07-2012
DOI: 10.1002/IJC.27677
Abstract: Suppression of neo-angiogenesis is a clinically used anti-tumor strategy with new targets such as angiopoietin-2 (Ang2) being proposed. However, the functions of Ang2 in vascular remodeling, inflammation and tumor growth are not consistent. We examined effect of depletion of host Ang2 on liver colony formation using Ang2 deficient (Ang2(-/-)) mice. Surprisingly, the metastatic colonies formed in Ang2(-/-) mice were larger than those in the wild type. These colonies had greater vascular density with more pericyte coverage than the vessels in liver colonies in the wild type. Liver VEGF concentration in both genotypes was equivalent, and thus, the differences appeared VEGF independent. However, after colony formation, the serum concentration of granulocyte-colony stimulating factor (G-CSF) and CXCL1 in Ang2(-/-) mice was 12 and 6 times greater than after colony formation in wild type. Increase of these two cytokines was associated with two times greater numbers of neutrophils recruited to the liver. Two times more Tie2+/CD11b+/CD31- cells were present in the tumors in Ang2(-/-) than in the wild type livers. These results suggest that the depletion of host Ang2 induced compensatory VEGF-independent angiogenic mechanisms and thus enhanced liver metastatic colony growth and colony vascularity. They further indicate organotypic differences in response to tumor metastasis. In contrast, Ang2 deficiency inhibited tumor growth during metastatic colony formation in the lung, consistent with the reports of decreased pulmonary seeding of tumor cells after pharmacological inhibition of Ang2. Further studies are thus required to assess the effects of pharmacological Ang2 blockade for cancer patients particularly in the liver.
Publisher: Frontiers Media SA
Date: 04-03-2022
Abstract: Uterine Fibroids, or leiomyomata, affect millions of women world-wide, with a high incidence of 75% within women of reproductive age. In ~30% of patients, uterine fibroids cause menorrhagia, or heavy menstrual bleeding, and more than half of the patients experience symptoms such as heavy menstrual bleeding, pelvic pain, or infertility. Treatment is symptomatic with limited options including hysterectomy as the most radical solution. The genetic foundations of uterine fibroid growth have been traced to somatic driver mutations ( MED12, HMGA2, FH −/− , and COL4A5-A6 ). These also lead to downstream expression of angiogenic factors including IGF-1 and IGF-2, as opposed to the VEGF-driven mechanism found in the angiogenesis of hypoxic tumors. The resulting vasculature supplying the fibroid with nutrients and oxygen is highly irregular. Of particular interest is the formation of a pseudocapsule around intramural fibroids, a unique structure within tumor angiogenesis. These aberrations in vascular architecture and network could explain the heavy menstrual bleeding observed. However, other theories have been proposed such as venous trunks, or venous lakes caused by the blocking of normal blood flow by uterine fibroids, or the increased local action of vasoactive growth factors. Here, we review and discuss the evidence for the various hypotheses proposed.
Publisher: Springer Science and Business Media LLC
Date: 30-01-2020
DOI: 10.1038/S41598-020-58362-3
Abstract: Endometriosis is a common gynaecological disease of women in reproductive age, and is thought to arise from retrograde menstruation and implantation of endometrial tissue, mostly into the peritoneal cavity. The condition is characterized by a chronic, unresolved inflammatory process thereby contributing to pain as cardinal symptom in endometriosis. Elevated reactive oxygen species (ROS) and oxidative stress have been postulated as factors in endometriosis pathogenesis. We here set out for a systematic study to identify novel mechanisms and pathways relating to oxidative stress in ectopic peritoneal lesions. Using combined proteomic and transcriptomic approaches, we identified novel targets including upregulated pro-oxidative enzymes, such as amine oxidase 3/vascular adhesion protein 1 (AOC3/VAP1) as well as downregulated protective factors, in particular alkenal reductase PTGR1 and methionine sulfoxide reductase. Consistent with an altered ROS landscape, we observed hemoglobin / iron overload, ROS production and lipid peroxidation in ectopic lesions. ROS-derived 4-hydroxy-2-nonenal induced interleukin IL-8 release from monocytes. Notably, AOC3 inhibitors provoked analgesic effects in inflammatory pain models in vivo , suggesting potential translational applicability.
Publisher: BMJ
Date: 03-2020
DOI: 10.1136/BMJOPEN-2019-032220
Abstract: Millions of women suffer from the consequences of endometriosis and uterine fibroids, with fibroids the cause for over 50% of hysterectomies in the USA, and direct costs for their treatment estimated at between US$4 and US$9 billion. Endometriosis commonly affects millions of women worldwide predominantly during reproductive age, with severe menstrual and non-menstrual pain and subfertility the main symptoms. Due to the ‘unhappy triad’ of endometriosis—lack of awareness, lack of clinically relevant biomarkers and the unspecific nature of symptoms—women wait on average for 8–12 years before the definitive endometriosis diagnosis is made. Treatment options for both conditions are not satisfactory at the moment, especially with a view to preserving fertility for the women and families affected. In the Fibroids and Endometriosis Oxford (FENOX) study, we combine the investigation of fibroids and endometriosis, and plan to collect high-quality tissue s les and medical data of participants over a time frame of 5 years after surgical intervention. Biological s les such as blood, saliva, urine, fat, peritoneal fluid and—if found—endometrial tissue or fibroids as well as detailed clinical and intraoperative data will be collected from women undergoing surgery and participating in the study after informed consent. We plan to recruit up to 1200 participants per disease arm (ie, endometriosis and uterine fibroids) over 5 years. Participants will fill in detailed and validated questionnaires on their medical history and quality of life, with follow-ups for 5 years. Enrolment started on 2 April 2018, and FENOX will close on 31 March 2028. We will analyse the biological s les using state-of-the-art molecular biology methods and correlate the findings with the medical records and questionnaire data. The findings will be published in high-ranking journals in the field and presented at national and international conferences. NCT13560263 .
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 Thomas Tapmeier.