The Cellular And Molecular Basis To The Paradox Of Positive Versus Negative T Cell Selection
Funder
National Health and Medical Research Council
Funding Amount
$278,090.00
Summary
The protection against disease requires the generation of white blood cells called T lymphocytes that are produced in the thymus. Each T cell has a specific surface receptor, generated by random gene switching, that can react against foreign pathogens. Since there is a very high conservation of molecules used in all organisms, some of these receptors could by chance also react against normal cells in the host. Eliminating all such self-reactive cells would mean, however, the repertoire remaining ....The protection against disease requires the generation of white blood cells called T lymphocytes that are produced in the thymus. Each T cell has a specific surface receptor, generated by random gene switching, that can react against foreign pathogens. Since there is a very high conservation of molecules used in all organisms, some of these receptors could by chance also react against normal cells in the host. Eliminating all such self-reactive cells would mean, however, the repertoire remaining for eliminating infection would be too low and immunodeficiency develops. This project investigates the mechanisms controlling the balance between defence infection and the need to prevent immune-based self destruction termed autoimmunity.Read moreRead less
The Generation, Fate And Functional Potential Of Recent Thymic Emigrants
Funder
National Health and Medical Research Council
Funding Amount
$318,856.00
Summary
A particular kind of white blood cell, called a T lymphocyte, is responsible for controlling our immune responses to foreign invaders. These cells develop in the thymus, where they learn to distinguish between foreign invaders and self tissue, before emigrating to other organs. The regulation of this process is important to maintain a pool of T lymphocytes in the body. It is important that T lymphocytes do not respond against self tissue, as this can lead to a Oself destructO disease called auto ....A particular kind of white blood cell, called a T lymphocyte, is responsible for controlling our immune responses to foreign invaders. These cells develop in the thymus, where they learn to distinguish between foreign invaders and self tissue, before emigrating to other organs. The regulation of this process is important to maintain a pool of T lymphocytes in the body. It is important that T lymphocytes do not respond against self tissue, as this can lead to a Oself destructO disease called autoimmunity. Since these developing T lymphocytes will not see all kinds of self tissue while in the thymus, we propose that their education to prevent self-tissue reactivity may continue for some time after they leave the thymus.Read moreRead less
Identification Of Antigen Selection In The Human IgE Response By Analysis Of Somatic Point Mutations
Funder
National Health and Medical Research Council
Funding Amount
$256,973.00
Summary
Allergic disease affects over 25% of the Australian community. It is responsible for significant sickness and death, particularly amongst children, and its incidence is on the increase. The reasons for this, and the underlying causes of allergic disease, remain unclear. Allergic disease results from the actions of molecules called IgE antibodies, which are also associated with parasitic infection. Even in these conditions, where IgE concentrations are raised in the blood, the concentrations are ....Allergic disease affects over 25% of the Australian community. It is responsible for significant sickness and death, particularly amongst children, and its incidence is on the increase. The reasons for this, and the underlying causes of allergic disease, remain unclear. Allergic disease results from the actions of molecules called IgE antibodies, which are also associated with parasitic infection. Even in these conditions, where IgE concentrations are raised in the blood, the concentrations are too low to allow their direct study. We have recently applied molecular biological techniques to study the genes that encode IgE antibodies. Our work suggests that the IgE response can sometimes develop in a different way to that of other antibodies (eg IgG). On the other hand, laboratory (in vitro) studies over many years support the possibility that IgE and IgG develop in parallel. In this study, we wish to identify circumstances in which IgG-like IgE antibodies develop. We therefore wish to study patients with different kinds of allergic disease, and patients with other conditions that are associated with IgE production. We therefore wish to study patients who have infections with parasitic worms. We deduce the processes that give rise to IgE antibodies by analysing patterns of mutations that accumulate in antibody genes during an immune response. Over recent years, we have developed new approaches to the analysis of such mutations, and this project also seeks to further develop our mutation analysis. This more powerful analysis will be applied to the study of mutations in the IgE genes seen in different patient groups, and should allow us to quantify the proportion of IgE antibodies that develop in each way. A better understanding of the relative contributions of the two pathways to IgE, in different conditions, will transform our understanding of the IgE response, and open up new avenues for the investigation of the causes and treatment of allergic disease.Read moreRead less
DETERMINING THE ROLE OF ER STRESS INDUCED APOPTOSIS IN THYMIC NEGATIVE SELECTION
Funder
National Health and Medical Research Council
Funding Amount
$558,189.00
Summary
Apoptosis is an evolutionarily conserved mechanism for killing unwanted cells that are no longer needed, damaged, infected with pathogens or dangerous. Defects in apoptosis can cause a number of diseases. For example, abnormal survival of cells can cause cancer or autoimmune disease. Bim is a protein that induces apoptosis and act as a barrier against cancer and autoimmune diseases. This work is aimed at understanding how Bim acts as a barrier against the development of autoimmunity.
How Does The P75 Neurotrophin Receptor Transmit Both Pro-survival And Pro-apoptotic Signals In Neurons?
Funder
National Health and Medical Research Council
Funding Amount
$265,500.00
Summary
Signaling by the two NGF receptors, TrkA and p75, determines the survival or death of sensory neurons and of certain brain neurons involved in memory and learning. The most baffling aspect of these receptors is that in most circumstances they cooperate with each other to maximise the survival of neurons when NGF is present, but in some situations they are opposed to each other. In the latter case, NGF treatment can lead to death, rather than rescue, of neurons. In the last three years we have de ....Signaling by the two NGF receptors, TrkA and p75, determines the survival or death of sensory neurons and of certain brain neurons involved in memory and learning. The most baffling aspect of these receptors is that in most circumstances they cooperate with each other to maximise the survival of neurons when NGF is present, but in some situations they are opposed to each other. In the latter case, NGF treatment can lead to death, rather than rescue, of neurons. In the last three years we have developed novel antisense oligonucleotides which can be used to switch off each receptor separately. These have been, and will continue to be, particularly valuable tools for our research. We have also uncovered a novel way in which the two receptors interact (via a signal transduction molecule known as SHC), which provides us with a competitive edge in this area. We have the expertise and equipment to identify and clone the missing factors that account for the paradoxical interactions between p75 and TrkA. A successful outcome from this project will have important benefits by improving our understanding of the factors controlling neuronal fate, and will help to develop treatments for neurodegenerative diseases.Read moreRead less
Finding The Optimum Target And Predictors Of Outcome In Deep Brain Stimulation Of Older Patients With Parkinsons Disease
Funder
National Health and Medical Research Council
Funding Amount
$428,392.00
Summary
Parkinson's disease treatment has been revolutionised by the advent of deep brain stimulator surgery. The major benefits come from improved motor function and quality of life. We aim to test the relative benefits of two different targets for brain stimulation and compare their effects on quality of life and cognition. We will also use some of Australia's expertise in brain scanning technology to look for pre-operative predictors of treatment outcomes in this group of older patients with PD.