FIGURE 3.

PRMT5 plays a role in peripheral T cell maintenance and early T cell development in a cell-intrinsic manner. Lethally irradiated CD90.2⁺ CD45.1⁺ wildtype mice (n = 4/group) were reconstituted with a 1:1 mixture of bone marrow cells from CD90.1⁺ CD45.2⁺ wildtype mice and CD90.2⁺ CD45.2⁺ Cre-ERT2 control or Cre-ERT2 PRMT5^fl/fl mice. The mixed bone marrow chimeras were treated with tamoxifen for five consecutive days and the spleen (A–C) and thymus (D–F) were analyzed by flow cytometry at 10 days after the last treatment. (A) Representative plots show the expression of YFP on donor CD45.2⁺ CD90.2⁺ CD8⁺ T (TCRβ⁺ CD8a⁺), CD4⁺ T (TCRβ⁺ CD4⁺), and iNKT (TCRβ⁺ CD1d tet⁺) cells in the spleen of mixed bone marrow chimeras. YFP⁺ CD8⁺ and CD4⁺ T cells were further analyzed for the expression of CD62L and CD44. (B) The frequencies of YFP⁺ cells among donor cells shown in (A) are plotted as mean ± SEM. (C) The frequencies of CD44^high cells among YFP⁺ CD8⁺ and CD4⁺ T cells are plotted as mean ± SEM. (D) Representative plots show the expression of YFP on donor CD45.2⁺ CD90.2⁺ DN (CD8a^– CD4^– TCRβ^–), DP (CD8a⁺ CD4⁺), CD8 SP (CD8a⁺ CD4^– TCRβ⁺), CD4 SP (CD8a^– CD4⁺) and iNKT (TCRβ⁺ CD1d tet⁺) cells in the thymus of mixed bone marrow chimeras. YFP⁺ DN cells were further divided into DN1 (CD44⁺ CD25^–), DN2 (CD44⁺ CD25⁺), DN3 (CD44^– CD25⁺), and DN4 (CD44^– CD25^–) developmental subsets. (E) The frequencies of YFP⁺ cells among donor cells shown in (D) are plotted as mean ± SEM. (F) The frequencies of DN subsets among YFP⁺ DN are plotted as mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, by unpaired two-tailed Student’s t-test. CD1d tet, CD1d tetramers loaded with PBS-57; NS, not significant; WT, wildtype.