Interactions between pulmonary surfactant and alveolar macrophages in the pathogenesis of lung disease.

This article reviews recent findings regarding interrelationships between the pulmonary surfactant system and alveolar macrophages in the pathogenesis of human lung diseases, including pulmonary alveolar proteinosis, pulmonary infection, inflammation and obstructive lung diseases. Various components of pulmonary surfactant interact with alveolar macrophages in the modulation of innate host defense responses of the lung. In a reciprocal manner, alveolar macrophages regulate surfactant homeostasis, influencing rates of surfactant protein and phospholipid clearance and catabolism. Increasing evidence suggests that the complex interactions between the surfactant system and the alveolar macrophage are intrinsically linked to development of various lung diseases.