I am an immunologist investigating the interactions between the liver and the immune system in order to understand the tolerogenic property of this organ.
Role Of Hepatocytes In Inducing Primary CD8+ T Cell Activation And Tolerance
Funder
National Health and Medical Research Council
Funding Amount
$159,662.00
Summary
It is well known that tolerance to liver allografts is more readily achieved than to other organ grafts, even across a major histocompatibility (MHC) barrier. According to some experiments, preferential tolerance to liver grafts may be due to development of chimerism involving the very large number of passenger leukocytes of donor hematopoietic origin present in an organ of this size. However, such a concept does not explain all the available data, particularly those relevant to CD8+ T cells, th ....It is well known that tolerance to liver allografts is more readily achieved than to other organ grafts, even across a major histocompatibility (MHC) barrier. According to some experiments, preferential tolerance to liver grafts may be due to development of chimerism involving the very large number of passenger leukocytes of donor hematopoietic origin present in an organ of this size. However, such a concept does not explain all the available data, particularly those relevant to CD8+ T cells, the primary effectors of graft rejection. Moreover, it does not take into account the fact that the liver possesses a unique fenestrated endothelium which is permeable to naive as well as activated T cells, nor the tolerogenic properties of hepatocytes themselves. Our recent experiments suggest that the liver is a site of primary activation for CD8 T cells and that a normal liver contains a significant number of self-reactive CD8+ T cells. The aim of this project is to determine whether activation of CD8+ T cells by hepatocytes contributes to the striking ability of liver grafts to be accepted and to induce tolerance in the CD8 T cell compartment. This would indicate that the liver plays an important role in peripheral tolerance of CD8+ T cells, providing the basis for novel therapies in transplantation and the treatment of autoimmune diseases. Moreover, this project also aims to generate a unique animal model of chronic liver inflammation in the absence of viral infection. Such a model is needed to study cirrhosis and hepatocarcinoma in the absence of potential oncogenes carried by viruses such as hepatitis B.Read moreRead less
Transgenic Mice : A Unique Model To Reassess Specific T Cell Suppression
Funder
National Health and Medical Research Council
Funding Amount
$272,545.00
Summary
Acceptance of transplanted organs is currently achieved by treating the recipient with immunosuppressive drugs that block T cell responses. However, because these drugs are non-specific, they will block all T cell responses, including those directed to undesirable viral or bacterial infections. So, whilst this strategy is the best available at the moment, it is far from ideal. The best treatment would be to induce specific graft acceptance without immunosuppression. In the 1970 s several studies ....Acceptance of transplanted organs is currently achieved by treating the recipient with immunosuppressive drugs that block T cell responses. However, because these drugs are non-specific, they will block all T cell responses, including those directed to undesirable viral or bacterial infections. So, whilst this strategy is the best available at the moment, it is far from ideal. The best treatment would be to induce specific graft acceptance without immunosuppression. In the 1970 s several studies have described treatment of recipients achieving specific suppression mediated by a subset of T lymphocytes. Although the phenomenon can be observed, no consensus has been reached to explain the mechanisms involved in the different models. One reason was the unability to track a population of suppressive T cells. We have now the technology and more knowledge to reassess these studies and understand how specific suppression can be achieved. Our lab has developed transgenic mice to study these phenomenon. One of our transgenic models mimicks the T cell response following liver transplantation. Acceptance of liver transplants is more readily achieved than to other organ grafts, even across a major histocompatibility (MHC) barrier and without immunosuppressive drugs. Not only are liver transplants well accepted, but they may induce secondary acceptance of kidney or heart grafts from the same donor, which would otherwise be rejected. Although this property has been made use of by surgeons, the amazing capacity of the liver to be accepted and to induce acceptance of other organs is still not understood. Previous studies and our own model suggests that specific suppression is involved. Our model which enable us to track the relevant cells provides therefore a unique tool to understand how specific suppression can be achieved. Understanding these mechanisms would help us to design strategies to induce tolerance to any organ without immunosuppressing the patient.Read moreRead less
Cholestasis And Hepatocyte Injury In Chronic Liver Disease
Funder
National Health and Medical Research Council
Funding Amount
$615,967.00
Summary
The aim of this project is to understand the consequences of long-term cholestasis or impaired bile excretion/flow on normal liver cells (hepatocytes) and to test whether specific bile acids can cause irreversible damage to hepatocytes leading to their transformation into pre-malignant cells and hepatocellular carcinoma (primary liver cancer). The results from this project will inform new strategies in screening, prevention and treatment of liver cancer in children and adults with cholestasis.
Significance Of Microparticles In The Pathogenesis Of Liver Ischemia Reperfusion Injury
Funder
National Health and Medical Research Council
Funding Amount
$643,958.00
Summary
The overall aim of the project is to investigate the significance of microparticles in liver ischemia reperfusion injury (IRI). IRI causes damage to donor livers stored in preparation for liver transplantation. We postulate that microparticles released from the liver are critical in this form of injury. The expected outcomes are novel insights into liver IRI with the aim of developing new approaches to prevent liver damage during liver surgery, transplantation and shock.
The Role Of MBOAT7 In Hepatic Inflammation: Implications For Therapy
Funder
National Health and Medical Research Council
Funding Amount
$848,340.00
Summary
When a fatty liver progresses to develop inflammation, patients are at-risk of liver-related morbidity and death. Currently, there are no effective therapies. From human studies, we have discovered that a lipid modifying enzyme (MBOAT7) profoundly regulates liver inflammation. In this proposal, we will obtain a detailed understanding of how the activity of this pathway modulates inflammation. We expect to show that MBOAT7 is a novel ‘druggable’ pathway for the treatment of liver inflammation.
P53 And Hepatocyte Proliferation In Chronic Liver Disease
Funder
National Health and Medical Research Council
Funding Amount
$331,360.00
Summary
The aim of this project is understand how loss of control of p53, a tumour suppressor gene, in liver cells causes the transformation of normal liver cell (hepatocyte) to ‘rouge’ pre-cancerous cells in hepatocellular carcinoma (HCC) or primary liver cancer. We will test novel therapies to restore p53 function in liver cells in order to prevent or retard the development of HCC in patients with cirrhosis and those ‘at risk’ of this rapidly increasing fatal cancer in Australia.
MERTK Receptor Tyrosine Kinase: A Novel Therapeutic Target For Liver Fibrosis
Funder
National Health and Medical Research Council
Funding Amount
$870,972.00
Summary
Hepatic fibrosis is the principal cause of liver-related morbidity and mortality, for which there are no effective therapies. Thus, there is an urgent and unmet need to identify new targets to treat liver fibrosis. We have demonstrated for the first time, that liver fibrosis correlates with elevated hepatic expression of MERTK, a receptor tyrosine kinase. This project will explore whether MERTK function can be exploited to target and reverse liver fibrosis
The Role Of The Hepatocyte And EMMPRIN In Liver Injury
Funder
National Health and Medical Research Council
Funding Amount
$607,487.00
Summary
This research plan investigates the role of the hepatocyte, the principal functional cell within the liver in the development of liver disease. Liver injury can result in end-stage scaring known as cirrhosis as well as leading to liver cancer. Our research aims to identify strategies for reversing the fibrotic process and result damage to the liver