Figure 4

TSLP increases proliferation of DN1 and DN2 thymocytes in FTOC. E17 FTOCs were cultured with or without TSLP (30 ng/ml) for 48 hours, and BrdU was added for the last 4 hours before analysis. (A) Thymocytes from each FTOC lobe were harvested, stained for CD44, CD25, CD3, CD4, CD8 and BrdU. Thymocytes that were negative for expression of CD3, CD4 and CD8 were analyzed for DN subpopulations and relative BrdU incorporation. (B) The same thymocytes were analyzed for BrdU incorporation in CD3⁺CD4⁺ or CD3⁺CD8⁺ cells. The data is representative of two independent experiments. *, indicates p < 0.05; **, p < 0.01.