Thymic Epithelial Requirement for gamma delta T Cell Development Revealed in the Cell Ablation Transgenic System with TSCOT Promoter

• Published in: Molecules and cells 2012, 34(5), , pp.481-493
• Main Authors: Gwanghee Lee, 김문교, 김기연, Cheong-Hee Chang
• Format: Article
• Language: English
• Subjects: 생물학
• ISSN: 1016-8478; 0219-1032
• DOI: 10.1007/s10059-012-0246-4

In order to investigate the role of thymic epithelial cell (TEC) subsets during T-cell development, we established a new transgenic system, enabling inducible cell-specific ablation as well as marking the TEC subsets using bicistronic bacterial nitroreductase and EGFP genes. Two different lengths of the TSCOT promoter in transgenic mice, named 3.1T-NE and 9.1T-NE, drive EGFP expression into TECs. In adult life, EGFP expression was located in the medulla with a smaller 3.1 kb TSCOT promoter, while it was maintained in the cortex with a 9.1 kb promoter, suggesting putative TEC specific as well as compartment specific cis elements within two promoters. Nitroreductase induced cell death was specific without bystander killing upon the treatment of prodrugs such as nitrofurantoin and metronidazol. The degree of cell death was dependent on the dose of the prodrug in the cell and the fetal thymic organ cultures (FTOCs). Fetal thymic stromal populations were analyzed based on the expression levels of EpCAM, MHCII, CDR1 and/or UEA-1. EGFP expression patterns varied among subsets indicat-ing the differential TSCOT promoter activity in each TEC subset. Prodrug treatment in FTOCs reduced the numbers of total and subsets of thymocytes. A CD4+CD8+ double positive cell population was highly susceptible in both transgenic lines. Surprisingly, there was a distinct reduction in  T cell population only in the 9.1T-NE thymus, indicating that they require a NTR-EGFP expressing TEC population. Therefore, these results support a division of labor within TEC subsets for the  and  lineage specification. KCI Citation Count: 3