Dividing Functions of Thymic Microenvironment using Thymic Epithelial Cell Specific Ablation in the Mouse

초록

During thymopoiesis, highly regulated interactions between thymocytes and surrounding stromal cells occur in particular compartments of the thymic microenvironment. Molecules on these stromal cells directly or indirectly regulate genetic programs for thymocyte survival, traffic, selection, and lineage commitment. The gene encoding E. coli NTR was specifically expressed in the thymic epithelial cells of the transgenic mice using TSCOT promoter. EGFP expression driven by 3.1kb promoter appeared in the medullar region of thymus while 9.1kb promoter in the cortex. Treatment with the pro-drugs NFT and MTZ that produce apoptosis inducing products by NTR in the fetal thymic organ culture as well as in adult animals resulted in a dose dependant depletion of diverse thymocyte population. The varying degree of the reduction in the numbers of thymocyte population was due to the absence of the specific thyimic epithelial compartments of different NTR transgenic mouse systems carrying the different sizes of TSCOT promoter. As a result, these data suggest that transgenic mouse model system for thymic epithelial cell specific ablation using NTR was successfully established.