Figure 1.

CD8 SP thymocytes become memory-like CD8⁺ T cells by IL-4 produced from PLZF^high T cells. ETPs from bone marrow migrate to the thymus and differentiate into CD8 or CD4 SP thymocytes in the medulla. In WT BALB/c mice, IL-4 from iNKT cells conditions SP thymocytes to become memory-like cells expressing Eomes. CD4 SP thymocytes (dotted line) are much less efficient to become Eomes-positive memory-like cells compared to CD8 SP thymocytes (solid line). These features are also seen in genetically altered B6 mice (listed on the right side), in which PLZF-positive iNKT or γδ T cells expand.

SP, single positive; ETP, early T cell progenitor; DP, double positive.