MCT Research Talks – 19th June 2017
Dr Rebecca Coll is a Research-Industry Fellow at the University of Queensland, studying innate immunity and novel anti-inflammatory drugs. Rebecca received her PhD in Immunology in 2013 under the supervision of Professor Luke O’Neill at Trinity College Dublin and moved to Associate Professor Kate Schroder’s group at the Institute for Molecular Bioscience in UQ in 2014. Over the last five years, her research has focused on inflammasomes – protein complexes at the heart of inflammation and disease – and how these complexes can be targeted therapeutically to prevent damaging inflammation.
Rebecca led the biological characterisation of MCC950, a small molecule inhibitor of the NLRP3 inflammasome and an exciting prospect as a new therapy for treating patients with NLRP3-mediated diseases. In 2016, Rebecca received the Research Australia Discovery Award for her work on MCC950.
MCT Research Talks – 24th April 2017
The main challenge in treating high-risk neuroblastoma is to combat tumour metastasis and development of resistance to multiple chemotherapeutic drugs. In the native tissue, cancer cells are surrounded by a three-dimensional (3D) microenvironment which provides biological and physical support and determines disease initiation, progression, patient prognosis and response to treatment. The conventional two-dimensional (2D) cell culture lacks this feature resulting in discrepancies between in vitro and in vivo results. Current neuroblastoma studies employ either 2D cell culture systems or murine models or alternatively a mix of both.
In collaboration with Dr Caroline Curtin and Prof Fergal O’Biren (TERG), we decided to bridge the gap between 2D culture and in vivo tumours in neuroblastoma research by developing a tissue-engineered cell culture model of neuroblastoma. This project is supported by a pilot grant from Neuroblastoma UK.
To understand what signalling pathways are activated in 2D, 3D and in vivo neuroblastoma models, we decided to look closer at the differences between conventional 2D neuroblastoma cells and their xenografts. This way we hope to find those targets that are activated in both tumour microenvironment and the 3D tissue engineered models. Ciara and Larissa have begun this search by profiling xenograft samples with a panel of antibodies. Ciara became particularly fascinated by the elevated levels of c-jun, TCF1 and LEF1 in cisplatin-resistant neuroblastoma xenografts suggesting that the development of cisplatin resistance in neuroblastoma may be accompanied by activation of the wnt/b-catenin pathway in vivo. Larissa identified that cisplatin-resistant neuroblastoma cells secrete chromogranin A (CgA) at levels higher that cisplatin-sensitive cells. CgA levels also correlated with increased vascularisation and volume of murine orthotopic neuroblastoma xenografts. Altogether it suggests that CgA can be used as a marker of neuroblastoma cell growth both in vitro and in vivo.
MCT Research Talks – 10th, April 2017
Research talks were presented by Sheila Zarros, Tatyana Devine, Afnan Ali and Padraig Norton. Tatyana and Sheila were talking about challenges in the characterisation of novel FCγRIIa inhibitors.
Fc receptors are a widely distributed family of receptors that mediate cellular responses to antibodies or immunoglobulins (Ig). The Fc gamma receptor II, FcgRII (also known as CD32) is a low-affinity receptor for Fc portion of immunoglobulin G (IgG) and has two isoforms FcgRIIa and b. Fcg RIIa is widely expressed by human innate immune cells and is the only Fc gamma receptor found on human platelets.
Our group and others have demonstrated the significance of this receptor in the activation of platelets by bacteria, suggesting that it could be an important target in the treatment of sepsis. Its implications in rheumatoid arthritis, cancer pathogenesis, allergic reactions and flu virus-induced thrombocytopenia were also demonstrated.
Our project is focused on characterisation of novel small molecule compounds designed for targeting FcgRIIa receptor’s IgG binding site to inhibit bacteria-induced platelet aggregation in primary human plasma and investigation of their interactions with the FcgRIIa using surface plasmon resonance technology.
Afnan Ali reported on the role of the Fc gamma Receptor IIa (FcγRIIa) in platelet activation. Platelets express the FcγRIIa and this receptor has been identified as a key receptor in bacterial activation of platelets leading to thrombocytopenia and platelet activation. The aim of this study was to identify drugs that could be re-purposed for the treatment of sepsis and immune-mediated thrombocytopenia. We identified 42 drugs predicted to inhibit binding of IgG1 to the FcγRIIa using virtual high throughput screening. This included 20 antibacterial agents, 3 anti-fungals, 3 antiviral agents, 7 antineoplastics and 3 immunosuppressives. A selection of drugs were tested for inhibition of platelet adhesion to IgG, S. aureus-induced platelet aggregation and assessed for platelet activation. This work has identified multiple drugs that have potential to be to be repositioned for thrombocytopenia, sepsis and autoimmune disorders, as well as providing a possible mechanism of action to explain the immunosuppressive effects of some anti-neoplastics and immunosuppressive drugs.
MCT Research Talks – 24th March 2017
Prof. Eric S. G. Shaqfeh, Qin M. Qi, Departments of Chemical and of Mechanical Engineering, Stanford University
The inhomogeneous center-of-mass distribution of red blood cells and platelets normal to the flow direction in small vessels plays a significant role in hemostasis, drug delivery and microfluidics. Under pressure-driven flow in channels, the migration of deformable red blood cells at steady state is characterised by a concentration peak at the channel center and a cell-free layer or Fahraeus-Lindqvist layer near the vessel wall.
Rigid particles such as platelets, however, “marginate” and thus develop a near-wall excess concentration. This margination controls the time it takes for the initial stages of platelet binding and clotting in response to trauma.
In this talk, we investigate the time-dependent concentration distribution of red blood cells and platelets in pressure-driven flow by developing and solving a Boltzmann model, advection-diffusion equation for both species. From a fluid mechanics point of view, deformability-induced hydrodynamic lift and shear-induced diffusion are essential mechanisms for the cross-flow particle migration and margination. The governing equation for the distribution of red blood cells includes both lift flux away from the wall and shear-induced diffusion due to cell-cell “collisions”. On the other hand, the governing transport equation for platelets includes shear-induced diffusion from cell-platelet “collisions” and platelet-platelet “collisions”. We demonstrate that these predictions are in good agreement with full boundary element simulations of the margination process and we also compare directly to experimental results. We then examine, within this model and our full boundary element simulations, the time evolution and “entrance length” for red blood cell migration and platelet margination. The resulting complete model can serve as a fast and computationally efficient alternative to large-scale simulation with the application, for example, as a real-time computational tool for microfluidic blood assay systems.
MCT Research Talks –13th March 2017
Jonathan Cowman reports
Cardiovascular disease (CVD) is the leading cause of death and disability in the world (approx. 1.9 million deaths per year within the EU). Platelet’s play a key role in this process and hence is why antiplatelet therapy such as aspirin is effective in reducing its incidences. Platelet function testing has a role in identifying those that are at high risk of a CVD related event (example a heart attack) and also identifying those patients that do not respond to their medication. There are a number of platelet function tests on the market however these tests suffer from a number of disadvantages such as expense, high sample volume, requirement for trained lab personal and single drug test capability.
My current research under the supervision of Prof. Dermot Kenny (RCSI) and Dr. Niamh Gilmartin (DCU and DIT) is to work alongside our multi-disciplinary team to produce a cost effective, rapid, small sample volume platelet function assay which can detect the effect of multiple antiplatelet drugs in a single patient blood sample. The project is known as the Platelet Monitoring Biochip (PMB). The PMB device consists of 6 micron sized fibrinogen dots, which are micro contact printed to a Zeonor (plastic) surface, a bright-field imaging system and a custom designed platelet analysis software. Blood is added to the device and rocked for 30 minutes to allow platelets to adhere to the fibrinogen dots. The device has 3 channels, a control (no agonist well), an adenosine diphosphate (ADP) well and an Arachidonic acid (AA) well which can be used to detect P2Y12 platelet inhibition and aspirin effect simultaneously. The PMB device provides a fast, easy and low cost way to determine the effectively of antiplatelet therapy against multiple agonists in whole blood. The device is currently in operation in RCSI Beaumont.
MCT Research Talks – 20th February 2017
Sinead Heavin reports
Epilepsy is a common neurological disorder that affects ~40,000 people in Ireland. There are many different types of seizures which are caused by uncontrolled electrical impulses in the brain. Anti-epileptic drugs control seizures for ~50% of people with epilepsy but up to ~30% of patients remain uncontrolled despite treatment with multiple drugs. Epilepsy is caused by a number of factors include stroke, trauma and infections. However, more recently we have learned that epilepsy can be caused by genetic mutations. Some epilepsies are heritable while others arise de-novo. Many patients with an intellectual disability (ID) also have epilepsy. Many of these patients lack a specific diagnosis due to limited testing and available investigations. We sequenced a cohort of 99 adult patients with epilepsy and ID on a custom gene panel of ~150 genes. A likely pathogenic variant was identified in 20 patients in 19 different genes, including SCN1A, DCX and DEPDC5, well-known epilepsy genes. Furthermore, we identified copy number variants in two patients which are likely causative. Further work is needed to investigate the phenotype-genotype correlations identified in this study and any potential treatment options that may arise.
MCT Research Talks – 13th February 2017
Dr. Claire McCoy
I have recently arrived as a Lecturer in Biochemistry/Immunology within the Molecular and Cellular Therapeutics Department at RSCI. I am a dedicated and passionate Biochemist/Immunologist who obtained a BA (Mod) in Biochemistry from Trinity College Dublin in 2001.
In 2006, I completed my PhD at the University of Dundee, Scotland after which I conducted my postdoctoral training in innate immunology with Prof Luke O’Neill. In 2010, I received a Marie Curie Mobility Fellowship where I gained scientific independence and re-located to the Hudson Institute of Medical Research in Melbourne, Australia. In 2014, I was awarded an Australian NHMRC project grant enabling me to lead an independent research team, conducting my research specifically on the regulation of microRNAs in innate immune cells, with a particular focus on inflammatory diseases such as Multiple Sclerosis.
My lab aims to understand how microRNAs regulate inflammation in disease. Our particular focus is how the pro-inflammatory microRNA, miR-155, plays a fundamental role in one immune cell subset called the macrophage. Macrophages are the sentinel cells of our immune system and quickly respond to infection to clear invading microbes. However, in chronic inflammatory diseases and autoimmunity, the presence of macrophages largely contributes to the damage, tissue destruction and symptoms associated with these diseases. Our research has shown that miR-155 is a key driver of this response. My lab aims to identify the molecular and functional mechanisms that underpin inflammatory macrophages, with the aim that miR-155 inhibition will lead to real therapeutic potential.
Multiple Sclerosis (MS) is a progressive degenerative disease where the prevalence in Ireland far exceeds the global average. Disease onset occurs between 20-40 years, an age critically affecting working and family life. To this day, there is no known cause and no cure for MS. Although, the early disease can be managed by current drug therapies, there is no treatment at the later progressive stages of disease, and no known treatments to repair the damage caused to the central nervous system. My research aims to uncover the role of macrophages in MS, and the contribution of miR-155 in this effect.
Claire McCoy is the recipient of a prestigious Marie Curie International fellowship and an Investigator Project Grant from the National Health and Medical Research Council (NHMRC), Australia. Altogether my research has attracted €800K in both national and international funding. I have published >21 highly cited and seminal publications in Nature Reviews Immunology, Nucleic Acids Research, Journal of Leukocyte Biology and Journal of Biological Chemistry. I am book editor for Springer Science, USA, as well as peer reviewer for international journals and funding agencies.
I will be talking about my research at 12pm TR4, Monday 13th Feb. The title of my talk will be ‘miR-155, a master regulator of the immune response’.
Dr. Claire McCoy
Lecturer in Biochemistry/Immunology,
Royal College of Surgeons in Ireland,
123 St Stephens Green,
MCT Research Talks – 30th January 2017
Last week’s departmental talks encompassed a Deep Dive into Clock biology in Macrophages affecting the Inflammatory Response. This area is the focus of the Immune-Clock laboratory of Dr. Annie Curtis, a recent recruit to RCSI.
Jamie Early (PhD student of the Curtis Lab) currently residing in the Luke O’Neill Laboratory presented his findings on the role of the circadian clock in suppressing inflammation in macrophages and if the anti-oxidant transcription factor and redox sensor NRF2 plays a role. His talk was titled ‘The macrophage clock is a key controller of the anti-oxidant and inflammatory response via the transcription factor Nrf2’.
Second up, we had Mariana Cervantes (PhD student and visiting scientist from the Instituto Politecnico Nacional (IPN) in Mexico) present her talk titled ‘The macrophage clock is having a profound impact on mitochondrial dynamics- what are the implications for inflammation?’
Mariana is interested in how mitochondria alter their morphology, either fusing together to form networks or fragmenting into smaller units termed fission. She is trying to uncover if the clock is regulating this process and if so what are the implications for the inflammatory response.
MCT Research Talks – 23th January 2017
Survival rates for breast cancer have risen significantly over the past few decades, in large part due to a considerable increase in the number of tumours detected via mammography at an early, more easily-treated stage. The presence of microcalcifications on a mammogram constitutes an important diagnostic clue to radiographers, with approximately 30% of invasive breast tumours and up to 90% of cases of ductal carcinoma in situ (DCIS) being detected by the presence of calcifications. Some studies have also suggested that the presence of calcifications may act as a prognostic factor, as patients presenting with breast tumours with associated calcifications have a worse prognosis than those without.
Despite their importance in breast cancer diagnosis, the exact mechanism by which microcalcifications are formed remains largely unexplored. Our group previously established the first in vitro model of mammary cell microcalcification (1) which we have recently extended to the human the breast cancer cell line MDA-MB-231. When cultured with a cocktail of osteogenic-reagents for a prolonged period, these cells produce deposits of calcium phosphate.
Using a combination of histological staining, quantitative measurement of calcium content, alkaline phosphatase activity and analysis of gene expression, we can monitor the changes in cell phenotype leading to onset of mineralisation. The nature of our model allows for easy manipulation of cell culturing conditions and by adding various inhibitory compounds or cytokines to our culture media, we can identify the key pathways and targets necessary for calcification production. In doing so, we hope to build up a comprehensive understanding of the cellular and molecular basis underlying the formation of these important diagnostic clues.
Cox RF, Hernandez-Santana A, Ramdass S, McMahon G, Harmey JH, Morgan MP. Microcalcifications in breast cancer: novel insights into the molecular mechanism and functional consequence of mammary mineralisation. Br J Cancer. 106(3):525-37 PMID: 22233923 (Jan 2012)
Shane O’Grady, Maria Morgan