マウス肺胞マクロファージ・コロニー形成細胞と気管内投与粒子の及ぼす影響

抄録

Murine pulmonary alveolar macrophages (PAM) form macrophage (Mφ) colonies by cultures with granulocyte-macrophage colony-stimulating factor (GM-CSF). These alveolar colony-forming cells (AL-CFC) were also radioresistant, and were maintained in mice depleted of bone marrow cells and monocytes by radiostrontium (⁸⁹Sr), with or without intratracheal instillation of foreign body Sephadex G50 beads. The intratracheal exposures to either crocidolite asbestos or silica particles, however, induced a significant depletion of AL-CFC as well as decrease of PAM recovered, as compared to either untreated or TiO₂-exposed animals, suggesting the toxic effects of fibrogenic particles on the self-renewal of PAM. These results indicate that radioresistant AL-CFC are putative precursors of PAM which are maintained in the pulmonary alveoli independently of recruited mononuclear phagocyte precursors.