Figure 6.

Purified thymic epithelial cells drive thymic growth. TECs (CD45⁻EpCAM⁺) and non-TECs (CD45⁺EpCAM⁻, including all live cells that did not fall into the TEC gate) were sorted from GFP⁺ fetal thymuses, and were injected into one thymic lobe of each middle-aged recipient mouse. Each mouse received 60,000–71,000 TECs or 360,000–400,000 non-TECs. After 45 days, thymuses were recovered and weighed. (A) Individual injected (Inj.) and uninjected (Uninj.) lobes were weighed from experimental mice. Left and Right lobes were compared in control mice. (B) Whole thymuses from control mice and mice that were intrathymically injected with either TECs or non-TECs were weighed. P values were determined using the paired (A) and unpaired (B) Student’s t-tests