In Vitro Model of Thymuc Micro-environment. Interaction between Epithelial and Lymphoid Cells of the Human Thymus: Nature of Signals
Tech Area / Field
- BIO-CGM/Cytology, Genetics and Molecular Biology/Biotechnology
8 Project completed
Senior Project Manager
Pobedimskaya D D
Institute of Immunology, Russia, Moscow
- Institute of Immunological Engineering, Russia, Moscow reg., Lyubuchany
- CRSSA, France, La Tronche\nHeinrich-Pette-Institute, Germany, Hamburg\nInstitut National de la Santé et de la Recherche Médicale / INSERM U 345, France, Paris
Project summaryApplication of the new test-system for the in vitro modeling of events taking place in the human thymus between epithelial cells (TEC) and thymocytes is suggested. As a result of these interactions thymocytes are differentiated in T-lymphocytes, migrate to the peripheral organs of immune system and blood for the implementation of immune supervision. This test-system is based on co-cultivation of TEC derived from the human thymus with freshly isolated thymocytes. The unique feature of this test-system is activation of TEC in response to addition of thymocytes accompanied by secretion of thymic hormones and cytokines and programmed death of thymocytes. These phenomena relate to the events, which occur during thymocyte development in the thymus. Analysis of their mechanisms is important for elaboration of approaches to correction of disturbances in Т-cell maturation.
The objective of proposed project is the study of the processes of thymocytes development under the influence of the unique human thymic epithelial cell line (TEC) derived by the authors of the project.
Main tasks which will be decided:
- determination of the role of some membrane molecules, cytokines and hormones in TEC-thymocyte interaction;
- establishment of some mechanisms of intracellular signal transduction essential for selection of "perspective" clones of thymocytes and elimination of clones capable to become autoaggressive - principal process deriving in thymus;
- study of the possibility of TEC to eliminate leukemia cells in the blood of patients, estimation of effects of some drugs and physical actions on TEC production of thymus hormones.
The project will be carried out with the use of various methods of cellular and molecular biology: conventional methods of cell cultivation and estimation of cell proliferation; detection of apoptosis using biochemical, morphological and cytofluorometric approaches; immunoenzyme and radioimmune assays of cytokines and thymic hormones; cytofluorometric determination of cell surface markers; radioligand study of cell receptors for cytokines and thymic hormones; inhibitory analysis of investigating processes; immunoblot analysis of protooncogen expression and tyrosine phosphorylation of intracellular proteins; measure of intracellular concentration of Ca++ and ATP.
The scientific novelty of planned studies. New data will be obtained about the nature, mechanisms and results of interaction between epithelial and lymphoid cells of human thymus, the role of surface and secreted molecules and mechanisms of intracellular signaling in the development of T-lymphocytes in thymus. In more general sense they will be useful for comprehension of the nature of positive selection of thymocytes, biological significance of lymphocyte-epithelial cell interactions.
The applied significance of work consists in the elaboration of new approaches to regulation of hormone production and other expressions of TEC activity. The new test-system will help to study the processes of T-lymphocyte maturation and the effects of drugs as well as of the adverse factors of media on the thymic microenvironment and its production of hormones. These approaches will be used for the selection of thymotropic drugs.
Commercial value is demonstrated by TEC line from human thymus, which maybe exploited to study in vitro thymic epithelium, as well as for solution of numerous applied problems.