Figure 1: Decreased thymic negative selection in Il23 p19^−/− mice.

(a) Hematoxylin and eosin (H&E) staining of thymus from the indicated male mice. Enlarged images of the outlined area from upper images are shown below. (b) H&E staining of thymus from the indicated female mice. The object lens used to acquire the images is shown. Scale bars in a and b, 300 μm. (c–h) Flow cytometry analysis of the frequency of H-Y TCR⁺ thymocytes and the distribution of CD4/CD8 in H-Y TCR⁺ thymocytes in (c) male Il23 p19^+/+ Tg, (d) male Il23 p19^−/−Tg, (f) female Il23 p19^+/+ Tg and (g) female Il23 p19^−/−Tg mice. In each group, all samples were gated first on Thy1.2⁺ cells. Numbers shown within each quadrant indicate the percent cells in the quadrant. Cell counts of the indicated populations of thymocytes (e,h). All populations were gated within the TCR D^b/H-Y⁺ thymocytes. All results shown were calculated based on the percentage of each subpopulation of thymocytes multiplied by the total thymocyte count multiplied by 10⁻⁶. (i) Immunohistochemistry staining of thymic DCs (S100⁺, magenta) and apoptotic cells (TUNEL⁺, dark brown). The object lens used to acquire each panel of image is shown at the bottom. Scale bar, 100 μm. (j) The percentage of TUNEL⁺ cells at the indicated thymic region was quantified in five randomly chosen microscopic areas from each section. All results represent the mean±s.e.m. (N=2–3 mice per group for three independent experiments; **P<0.01 and ***P<0.005 between p19 Il23^+/+ D^b/H-Y Tg male and p19 Il23^−/−D^b/H-Y Tg male mice).