Changes in the fate of thymic emigrants during foetal and postnatal development in sheep [ 2000 - 2000 ]

Research Grant

Researchers: Prof Ross Cahill (Principal investigator)

Brief description 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.

Funding Amount $AUD 62,744.01

Funding Scheme NHMRC Project Grants

Notes Bridging