Fig. 3: AT2 MHCII is dispensable for immune homeostasis in the lung in 12-week-old mice.
a MHCII expression by AT2s from naive SPC-Cre-ERT2+/− (SPCCre), H2-Ab1fl/fl (Ab1fl/fl), and SPC-Cre-ERT2+/− × H2-Ab1fl/fl (SPCΔAb1), lungs measured by flow cytometry; histograms represent n > 50 mice per strain total from >10 independent experiments. b Immunofluorescence detection of MHCII (yellow), SPC (red), E-Cadherin (gray), and DAPI (blue), in Ab1fl/fl, SPCΔAb1, and MHCII−/− lungs; scale bar depicts 20 μm, representative images of n = 2 mice each for Ab1fl/fl and SPCΔAb1 strains and n = 1 for MHCII−/−. c, d Percent and MFI of each cell type expressing MHCII protein for lung AT2s, B cells, alveolar macrophages, CD103+ DCs, and spleen B cells and CD8+ DCs, from naive SPCCre, Ab1fl/fl, and SPCΔAb1 mice, measured by ex vivo flow cytometry analysis; bars show n = 4 mice per strain from one experiment, representative of two similar independent experiments for the Ab1fl/fl and SPCΔAb1 strains (n = 8 mice total per strain). e H&E staining of naive 12-week-old Ab1fl/fl and SPCΔAb1 lungs, images representative of n = 5 mice per strain. Scale bar depicts 200 μm. f–i Absolute number of lung CD4+ and CD8+ T cells (f), and frequency of lung CD4+ and CD8+ T cells expressing CD44, CD62L (g), Foxp3 (h), and CD69, CD11a (i), as indicated, from naive 12-week-old Ab1fl/fl and SPCΔAb1 mice measured by ex vivo flow cytometry analysis; each symbol represents n = 1 mouse, with n = 9 Ab1fl/fl and n = 10 SPCΔAb1 mice total displayed from one experiment, which is representative of two similar experiments. c, d, f–i Data shown are mean plus SEM, analyzed by two-tailed Mann–Whitney test (f [CD4s]) or unpaired two-tailed Student’s t-test (f [CD8s], g–i). Full statistical test results are in Supplementary Table 1. For a, c, d, f–I SPCCre are in black, Ab1fl/fl in gray, SPCΔAb1 in red. Source data are provided as a Source data file.
