Accelerating the Implementation of Mass Spectrometry in the Clinical Lab



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Plenary & Keynote Lecture Series

Distinguished Contribution Award Lecture

On the Award

>> Wednesday 16:30 in Mozart 1-5

Zoltan Takats
Imperial College London

Plenary Lectures

>> Tuesday 14:15 in Mozart 1-5
Inflammatory Stories in Time and Space: Using Mass Spectrometry Imaging, Ion Mobility and High Throughput Lipidomics to Understand Human Disease
Jules Griffin
Computational and Systems Medicine, Surgery and Cancer, Imperial College London, London and Department of Biochemistry, University of Cambridge, Cambridge, UK

A central aspect of the development of many of the pathologies associated with the metabolic syndrome is a chronic progression of inflammation in the affected tissues. This is in part driven by lipid remodelling in the cell membrane and the production of pro-inflammatory lipid mediators produced from polyunsaturated fatty acids such as arachidonic, docosahexaenoic and eicosapentaenoic acids. To explore lipid remodelling during the development of non-alcoholic fatty liver disease we have applied MALDI-based mass spectrometry imaging (MSI) to examine both human tissue and animal models of the disease progression. Using a combination of high fat feeding and genetic modification (the ob/ob mouse which lacks leptin) to cause hepatic steatosis with and without inflammation, MSI shows that one of the events associated with disease progression is a lipid remodelling of phosphatidylcholines (PCs), and in particular, a reduction in arachidonic acid containing PCs. We have also developed a ultra-high performance liquid chromatography ion mobility mass spectrometry-based method to profile known and novel lipid mediators, using a KNIME workflow to process the data and annotate the detected lipids, in part relying on collision cross-section values for these species to aid assignments. This will be illustrated in following the time course of lipid changes in thrombin activated human platelets.
>> Thursday 16:45 in Mozart 1-3
Donor-derived cell-free DNA as a biomarker in organ transplantation
Michael Oellerich
Institute for Clinical Pharmacology, University Medicine Göttingen, Germany

Molecular biomarkers have attracted special attention in solid organ transplantation because of unresolved problems that limit long-term outcome. There is a lack of reliable noninvasive markers. Immunosuppressive drug monitoring mainly indicates potential toxicity, but is a poor biomarker of graft damage. In kidney transplant patients, for example, an increase of plasma creatinine may be also be due to exsiccation, the use of ACE inhibitors, or immunosuppressive drug toxicity. By the time a rejection-related increase in plasma creatinine is evident, a significant degree of tissue damage has already occurred within the kidney. A further limitation of the current standard of care is that rejection episodes can only be confirmed by biopsies. Biomarkers are needed to achieve personalized immunosuppression to reduce premature graft loss. Against this background, a particularly promising new approach for the early detection of acute or chronic rejection or asymptomatic graft injury leading to irreversible damage is based on the determination of donor-derived circulating cell-free DNA (dd-cfDNA). Data on clinical validity have been documented in more than 48 independent studies which have shown that dd-cfDNA detects rejection episodes early, at an actionable stage, and is a more reliable marker of graft injury, compared to conventional tests. dd-cfDNA may also be useful to guide changes in immunosuppression, to monitor immunosuppression minimization (e.g. during tapering), and to prevent immune activation. The high negative predictive value of dd-cfDNA is the reason why this test can be helpful to avoid unnecessary biopsies. It could be shown that dd-cfDNA can be useful to detect subclinical (e.g. clinically unsuspected) graft damage as a result of immune activation triggered by under-immunosuppression. Early diagnosis of subclinical antibody-mediated rejection may improve outcomes after kidney transplantation. In summary, dd-cfDNA monitoring will allow more personalized treatment that shifts emphasis from reaction to prevention.

Keynote Lectures

Imaging the unimaginable with imaging mass cytometry
Frits Koning

The fetus is thought to be protected from exposure to foreign antigens, yet CD45RO+ T cells reside in the fetal intestine. Here we combined functional assays with mass cytometry, single-cell RNA sequencing and high-throughput T cell antigen receptor (TCR) sequencing to characterize the CD4+ T cell compartment in the human fetal intestine. We identified 22 CD4+ T cell clusters, including naive-like, regulatory-like and memory-like subpopulations, which were confirmed and further characterized at the transcriptional level. Memory-like CD4+ T cells had high expression of Ki-67, indicative of cell division, and CD5, a surrogate marker of TCR avidity, and produced the cytokines IFN-? and IL-2. Pathway analysis revealed a differentiation trajectory associated with cellular activation and proinflammatory effector functions, and TCR repertoire analysis indicated clonal expansions, distinct repertoire characteristics and interconnections between subpopulations of memory-like CD4+ T cells. Imaging mass cytometry indicated that memory-like CD4+ T cells colocalized with antigen-presenting cells. Collectively, these results provide evidence for the generation of memory-like CD4+ T cells in the human fetal intestine that is consistent with exposure to foreign antigens.
The development of targeted proteomic assays, attempting to take biomarkers from the research lab to the clinic
Kevin Mills
University of London

My talk will involve how my lab attempts to bridge the gap between finding a biomarker in a research lab to its validation and potential translation of that test into a clinical setting. I will give several examples of this consisting of finding biomarkers in plasma, urine and CSF followed by their translation into multiplexed tests. The diseases I will cover will include inborn errors of metabolism (Fabry Disease), hypertrophic cardiomyopathy and the neurodegenerative conditions of Alzheimer’s and Parkinson’s disease.
Rethinking sex steroids: Understanding the clinical relevance of 11-oxygenated androgens.
Karl Storbeck
Stellenbosch University

The C19 steroid 11β-hydroxyandrostenedione (11OHA4) is a major product of adrenal steroidogenesis, but was ignored for decades due to an apparent lack of activity. However, recent studies have demonstrated that 11OHA4 is the precursor to the potent 11-oxygenated androgens, 11-ketotestosterone and 11-ketodihydrotestosterone, that bind and activate the human androgen receptor with affinities and potencies similar to that of testosterone and 5α-dihydrotestosterone (DHT), respectively. The significance of these findings becomes apparent when considering androgen dependent diseases such as castration resistant prostate cancer and endocrine conditions associated with androgen excess such as polycystic ovary syndrome and congenital adrenal hyperplasia. Recent findings pertaining to the importance of the overlooked 11-oxygenated androgens will be presented, highlighting the role of 11-oxygenated androgens in disease states and challenging the paradigm that testosterone and DHT are the only clinically relevant androgens.
From Spectrometric Data to Metabolic Networks: An Integrated Quantitative View of Cell Metabolism
Oscar Yanes
Rovira i Virgili University & IISPV

INTRODUCTION: Metabolite profiling – or metabolomics – presents a powerful global approach to measure shifts in metabolites as functional readouts of cellular state. Metabolites can complement upstream biochemical information obtained from genes, transcripts, and proteins and advance our understanding of how cells are altered in health and disease. Unfortunately, the great success in the characterization of genes, transcripts and proteins has currently no parallel in metabolites. Metabolomic studies are revealing large numbers of naturally occurring metabolites that cannot be characterized because their chemical structures and spectrometric data are not available. This is preventing metabolomics from evolving as fast as other omic sciences, and thus it is restricting the integration of multiple layers of omic data to gain more insights into the emergence of observed phenotypes.
OBJECTIVES: To fill this gap, new experimental approaches based on mass spectrometry (MS), and innovations in bioinformatics to enable a comprehensive analysis of cellular metabolites are needed.
RESULTS: Here I will present novel computational tools for: 1) identifying and quantifying metabolites from reconstructed GC-MS, LC-MS and MALDI-MS spectral profiles; 2) the structural characterisation of unknown metabolites; and 3) the use of isotopically labeled metabolites to study the flow of chemical moieties through the complex set of metabolic reactions that happen in the cell. Finally, I will show that the integrated analysis of proteomics and metabolomics data through metabolic networks provides a new conceptual structure for an alternative quantitative and predictive description of cell metabolism.

Folker Spitzenberger
Technische Hochschule Lübeck