Figure 1. MHC class II restricted thymocytes are redirected to the CD8-lineage when HDAC3 is absent.

(A) CD4/CD8 profile of mature thymic SP (Vβ5⁺Vα2⁺H2K⁺CD24^lo) and splenic T cells (Vβ5⁺Vα2⁺) from OT-II, OT-II RORγt-KO Bcl-xl tg (RB) and OT-II RB3 mice. Graphs depict frequency of gated cells from at least three independent experiments (n = 3–5/group) (B) Runx3 and ThPOK expression in mature thymic SP cells from OT-II, OT-II RB, and OT-II RB3 mice (n = 4/group from four independent experiments). (C) CD4/CD8 profile of mature thymic SP from OT-II RORγt-KO and OT-II RORγt-KO HDAC3-cKO mice. Graphs depict frequency of gated cells from at least three independent experiments (n = 3–4/group). (D) Granzyme b and perforin expression in SP thymocytes from OT-II, OT-I, OT-II RB and OT-II RB3 mice. FACS plots were gated on CD4SP cells for OT-II and OT-II RB mice and CD8SP cells for OT-I and OT-II RB3 mice. Bar graphs depict mean ± SEM (n = 3/group from three independent experiments) of the fold change in MFI between unstimulated and TCR/CD2 stimulated conditions. (E) Representative FACS plots of the proportion of CD4SP and CD8SP mature thymocytes from straight BMCs, where bone marrow from OT-II or OT-II RB3 mice were transplanted into B6.SJL or β2m-KO recipients. Mature SP thymocytes were gated as Vβ5⁺Vα2⁺H2K⁺CD24^lo. Mice (n = 3–5/group from three independent experiments) were analyzed 8–10 weeks after transfer. (F) Representative FACS plots of the proportion of CD4SP and CD8SP mature thymocytes from mixed BMCs from OT-II (CD45.1^-)/B6.SJL (CD45.1⁺) and OT-II RB3 (CD45.1^-)/B6.SJL (CD45.1⁺) mice. Mature SP thymocytes from CD45.1⁺ cells were gated as H2K⁺CD24^lo; mature SP thymocytes from CD45.1^- cells were gated as Vβ5⁺Vα2⁺H2K⁺CD24^lo. Mice were analyzed 8–10 weeks after transfer. (n = 5/group from three independent experiments).