Role of the thymus in T cell homeostasis during foetal and postnatal life in sheep [ 2003 - 2005 ]

Research Grant

Researchers: Prof Ross Cahill (Principal investigator) ,  Wayne Kimpton

Brief description 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 cells, has considerable implications for the development of a pool of T cells able to respond to a large number of infections. Recent thymic emigrants represent a wide diversity of positively selected thymocytes exhibiting newly arising T cell specificities, but mature T cell pool expansion results in reduced diversity because of a predominant expansion of a limited number of clones. It follows that a mixing of the pool of older mature T cells with new ones just released from the thymus will introduce more variability, and hence greater adaptability into the immune system. We have developed techniques for labeling the thymus in vivo and the entire blood leukocyte pool in vivo using the long-term lymphocyte tracking dye CFSE. We can establish a cohort of labeled cells and we can, for the first time in any experimental system, track directly the survival, death or division of recent thymic emigrants and mature cells and their progeny together with their tissue homing properties and surface markers for periods of many months. 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 264,750.00

Funding Scheme NHMRC Project Grants

Notes Standard Project Grant