Thymic epithelial cell-derived signals control B progenitor formation and proliferation in the thymus by regulating Let-7 and Arid3a
Fig 3
Specific overexpression of Lin28a in HSCs caused a reduction of Let-7 and promoted thymic B cells production.
1×107 T/ B depleted BM cells isolated from 9-weeks iLin28a;Vav-iCre mice including Cre+ test and Cre- control group were transferred into lethally irradiated 8-weeks +/Z and Z/Z mutant mice respectively. The BM and thymic B progenitors (CD19+B220+CD24+CD43+/loIgM-) collected from host were analyzed at 21 days later. (A-D). Gene expression of Lin28a (A), Let-7b (B), Let-7g (C) and Arid3a (D) in host BM and thymic B progenitors were analyzed by Q-PCR. The value of gene expression in Cre- control BM cell was set as 1. Data are representative of three independent experiments (BM: n = 3, thymic B: n = 5 for each group). (E). Profiles of CD19 and CD24 expressions were shown in DN1 thymocytes. (F-G). Percentages of CD19+ cells in DN1 thymocytes (F) and a total number of CD19+ cells in the thymus (G) were summarized in the histogram. Data are representative of three independent experiments (+/Z: Cre- n = 3, Cre+ n = 3; Z/Z: Cre- n = 3, Cre+ n = 5). ns: not significant. nd: not detected. Student’s t-test results between Cre+ test and Cre- control groups: *P <0.05, **P <0.01, ***P <0.001. Bars indicate means ± SEM.