Lung Adenocarcinoma Originates from Retrovirus Infection of Proliferating Type 2 Pneumocytes during Pulmonary Post-Natal Development or Tissue Repair
Figure 3
Number of proliferating SP-C+ and CC10+ cells in healthy lambs and adult sheep.
(A) Analysis of proliferating type 2 pneumocytes was performed by counting SP-C/Ki67 double positive cells in 2–4 day-old lambs (n = 4) and adult sheep (n = 2) by confocal microscopy as described in Materials and Methods. 10 sections for each animal were analysed using by confocal microscopy and numbers of double positive cells were normalized to the sectioned area. Results shown are the average numbers of SP-C+/Ki67+ (± SD) per section for both groups of animals. (B) Representative image of a lung section from a 2 day old lamb analyzed by confocal microscopy using antibodies towards SP-C (showed in red) and Ki67 (showed in green). Nuclei were stained with DAPI and are shown in blue. Note that Ki67 is a nuclear marker and therefore positive signal appears in turquoise in the merged image. Arrows indicate SP-C+/Ki67+ cells. (C) Analysis of proliferating Clara cells was performed by counting the number of CC10+/Ki67+ cells in 100 terminal bronchioli per each animal as indicated in Panel A. Results shown are the average numbers of CC-10+/Ki67+ (± SD) per 100 terminal bronchioli for both groups of animals. (D) Representative image of a lung section from a 2 day old lamb analyzed by confocal microscopy using antibodies towards CC-10 (showed in green) and Ki67 (showed in red). Nuclei were stained with DAPI and are shown in blue. Arrows indicate CC-10+/Ki67+ cells.