Lung Defense Mechanisms

Abstract

(Second of Two Parts)MacrophagesThe alveolar macrophage system has been extensively studied. Alveolar macrophages are responsible for the physical removal of inhaled particles although the major clearance mechanism consists of the mucociliary transport system. Mackaness has shown^{151 152 153 154 155 156 157 158 159} that alveolar macrophages may be activated or armed in infectious processes to render them more capable of dealing with potential pathogens. Lymphocytes may be specifically sensitized to antigen and interact with macrophages, which themselves may become activated. Activated macrophages have a higher lysosomal enzyme level,¹⁵¹ are more phagocytic¹⁵⁴ and possess more bacteriocidal activity^{155 , 156} than nonactivated cells. Once activated, macrophages display non-antigen-specific capacity . . .