Figure 5.

Donor-derived Y-chromosome⁺ cells are embedded in the basal and columnar layers of the respiratory epithelium. Recipient female C57Bl/6 mice were inoculated with Pseudomonas aeruginosa at a dose of 10⁶ cfu. Male C57Bl/6 mice were used as donors. Bone marrow cells isolated from these mice were enriched in progenitor cells using the EasySep system. The cell suspension was injected intratracheally in mice infected with P. aeruginosa 2 days earlier. The mice were killed after 6 weeks and the lung sections were screened for Y-chromosome⁺ cells and cytokeratin (CK⁺) cells. (a) Y-chromosome⁺ cells (green) that are CK⁺ (red). (b,c) Enlarged micrographs of image a. (d,f) Other examples of Y-chromosome+ cells that express CKs. Arrows indicate donor-derived CK+ cells. (g–i) Images were taken at a confocal laser scanning microscope; g and h show Y-chromosome⁺ cells, (i) Y-chromosome⁺ cells (green) that are CK⁺ (red). Note that donor-derived cells are present in the basal and columnar layers of the respiratory epithelium. Micrographs are representative of lung sections obtained from four animals. Original magnification ×63, except b, c, h, and i (×100). cfu, colony forming units.