Fig. 1: CCR9 downregulation is associated with CD4 lineage specification.

a CCR9 expression was assessed on CD4 and CD8 spleen T cells. Results are representative of 14 independent experiments with a total of 16 WT mice. b CCR9 expression was assessed on TCRβ^hi mature CD4SP and CD8SP thymocytes. Results are representative of 14 independent experiments with a total of 16 WT mice. c Total thymocytes were assessed for CCR7 and CD69, whose differential expression identifies 5 distinct developmental stages of thymocytes (i.e., stages I–V). CCR9 expression was then assessed for each stage. Results are representative of 6 independent experiments with a total of 8 WT mice. d CCR9 expression on CD24^loTCRβ^hi mature CD4SP and CD8SP thymocytes. Results are representative of 6 independent experiments with a total of 6 WT mice. e CCR9 expression on post-selection CD4SP thymocytes. Post-selection (CCR7⁺TCRβ^hi) thymocytes were identified by CCR7 and TCRβ expression and then assessed for further maturation based on CD69 and MHCI expression (left). CCR9 expression was determined in CD4SP cells from semi-mature (SM), mature 1 (M1) or mature 2 (M2) thymocyte populations (right). The results are representative of 5 independent experiments with a total of 9 WT mice. f CCR9 expression on Runx3^Tg and Runx3d^KO thymocytes. CCR9 expression was determined on post-selection CD4SP cells of SM, M1, and M2 thymocytes of WT and Runx3^Tg mice (left), and on post-selection CD8SP cells of M1 and M2 thymocytes of WT and Runx3d^KO mice (right). Results are representative of 3 independent experiments with a total of 5 WT, 6 Runx3^Tg, and 4 Runx3d^KO mice. g ThPOK-GFP reporter (top) and CCR9 expression (bottom) on CD24^loTCRβ^hi mature CD4SP, CD8SP, and iNKT cells of ThPOK-GFP reporter thymocytes. Results are representative of 2 independent experiments with a total of 3 ThPOK-GFP reporter mice.