Label Retention Identifies a Multipotent Mesenchymal Stem Cell-Like Population in the Postnatal Thymus
Figure 1
Changes in H2BGFP expression within TECs in K5tTA;TetO-H2BGFP transgenic mice following a time course of Dox feeding.
A. Thymic sections prepared at the initiation of Dox feeding and from 2-6 weeks after the start of Dox feeding showing the reduction in H2BGFP expressing TECs. Sections were stained with anti-K8 (red) and anti-K5 antibodies (blue) to allow localization of the H2BGFP expressing nuclei within TECs. B. Representative FACS analysis of CD45- dissociated thymic stroma showing the frequency of EpCAM+ H2BGFP+ cells at time 0, 2, 4 and 6 weeks after the initiation of Dox feeding to inhibit H2BGFP expression in K5+TECs. Gates from left to right in each panel show the frequency of EpCAM+H2BGFP-, EpCAM+H2BGFPlo and EpCAM+GFPhi TECs at each time point. C. Graph shows the mean number of EpCAM+H2BGFPhi label-retaining cells and the number of EpCAM+H2BGFPlo cycling cells per thymus at 0, 2, 4, 6 and 12 weeks after the inhibition of H2BGFP expression through Dox feeding. Error bars are +/- the standard deviation of the mean. Results are representative of 3 independent experiments with 5 mice at each time point/experiment. D. Graph depicts the mean number of CD45- EpCAM+ TECs/thymus at 0, 2, 4, 6 and 12 weeks after the inhibition of H2BGFP expression through Dox feeding. Error bars are +/- the standard deviation of the mean.