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
Characterisation Of Cumulus Cell Molecular Mediators Of Oocyte Health
Funder
National Health and Medical Research Council
Funding Amount
$451,896.00
Summary
Many women are poorly fertile because of poor egg quality due to age, disease and lifestyle. IVF can assist, but requires large doses of hormone, which can lead to significant health risks. IVM is an alternative lab technique to IVF, but has very poor success. We discovered that synthetic proteins copied from recently discovered egg proteins can be added to the egg and substantially increase IVM success. Answering why will further will aid treatment for infertile women
Re-energising The Preimplantation Embryo To Extend Lifetime Health
Funder
National Health and Medical Research Council
Funding Amount
$1,156,936.00
Summary
Diseases of aging are associated with shortening at the ends of chromosomes called telomeres. The length of an individual’s telomeres is established during embryo development, and in situations where embryo development is compromised such as with maternal obesity the normal process of telomere lengthening may not occur. We will determine how such disruptions in embryo telomere lengthening contribute to poor health in adulthood and test ways to restore the natural process.
Changes In The Fate Of Thymic Emigrants During Foetal And Postnatal Development In Sheep
Funder
National Health and Medical Research Council
Funding Amount
$62,744.00
Summary
SIGNIFICANCE The mature T cell pool can arise from only two sources, either thymic export or expansion of the peripheral T cell pool or a mixture of both. The lifespan of either cell type, i.e. recent thymic emigrants or mature T cell, has considerable implications for the development of the T cell repertoire. Recent thymic emigrants represent a wide diversity of positively selected thymocytes but mature T cell pool expansion results in reduced diversity because of a predominant expansion of a l ....SIGNIFICANCE The mature T cell pool can arise from only two sources, either thymic export or expansion of the peripheral T cell pool or a mixture of both. The lifespan of either cell type, i.e. recent thymic emigrants or mature T cell, has considerable implications for the development of the T cell repertoire. Recent thymic emigrants represent a wide diversity of positively selected thymocytes but mature T cell pool expansion results in reduced diversity because of a predominant expansion of a limited number of clones. A high rate of continuous substitution of mature T cells in the peripheral pool with freshly arriving recent thymic emigrants exhibiting newly arising TCR not previously existing will produce higher adaptive capabilities for the immune system. We have developed techniques for labeling the thymus in vivo by intra-thymic injection with the long-term lymphocyte tracking dye CFSE. We can establish a cohort of labeled recent thymic emigrants and we can, for the first time in any experimental system, track directly the survival, death or division of recent thymic emigrants and their progeny together with their tissue homing properties and surface markers for periods of many months after they leave the thymus. This will enable us to determine the way in which the pool of mature T cells is built up during the formation of the foetal immune system and the way the mature T cell population is established and maintained in postnatal life.Read moreRead less