Session I: Immune – stromal cell networking during development
Thursday March 30, 2017
11.15 Graham Anderson, Birmingham, United Kingdom
"The ins and outs of T-cell development in the thymus"
MRC Centre for Immune Regulation, Institute for Immunology and Immunotherapy, University of Birmingham, United Kingdom.
T-cell development in the thymus involves a series of inter-linked processes that result in the progressive differentiation of immature thymocytes towards functionally competent T-cells. These include the regulation of T-cell commitment, and positive and negative selection of the emerging T-cell receptor repertoire. The programme of T-cell development also involves several migration steps that are essential for T-cell production. For example, the thymus recruits early lymphoid progenitors from the bone marrow via chemokine-mediated mechanisms, a process that is important in both the steady state and during immune reconstitution that follows bone marrow transplantation for cancer treatment. Additionally, thymocyte migration controls exit from the thymus and the entry of mature CD4+ and CD8+ thymocytes to the periphery. The regulators of this process are still only partly understood. Critically, as these stages of thymocyte development are non-cell autonomous, they require continual input from heterogenous stromal cells that collectively comprise specialised thymic cortical and medullary microenvironments. Thymic epithelial cells (TEC) in particular are key stromal regulators of thymocyte development that operate at multiple stages. At this meeting, data will be presented on the mechanisms that control entry and exit from the thymus, focussing on the stromal cell types that control these processes.
12.00 Martijn Nolte, Sanquin, The Netherlands
"Back to the roots: Networking T cells in the bone marrow"
Martijn Nolte, Sanquin, Amsterdam, The Netherlands. (email@example.com)
Bone marrow is a highly dynamic organ, in which cellular networking is essential to ensure the continuous release of new blood cells, which has been estimated at a staggering rate of ~5 million cells per second! The hematopoietic process responsible for this huge production is tightly controlled, as too few or too many blood cells is obviously detrimental to human health and will have clinical consequences. A balanced level of differentiation of hematopoietic stem or progenitor cells to mature blood cells is already an intricate process during the steady state, but it becomes even more complex upon infection. When we are under attack from a pathogen, the bone marrow receives cues to enhance the production of the appropriate type of blood cell to combat the infection, whereas the generation of other cell types is temporarily inhibited1. Although it has been recognized that such a tailored response from the bone marrow occurs during an infection2, the underlying cellular and molecular mechanisms are not yet fully understood. In recent years, we have analyzed the presence and function of T cells inside the bone marrow and in this lecture I will show that these immune cells are important regulators of hematopoiesis. (read more)