Pkagocyt ~ c Properties of BCG-Induced Alveolar Macrophages

The preceding article (1) delineated the nature and properties of the hydrolase-containing cytoplasmic granules of the BCG-induced alveolar macrophage. These organelles represented a spectrum of morphological types which were considerably denser than mitochondria, were stained with vital dyes, and contained large amounts of hydrolytic enzymes. These enzymes exhibited the property of "latency," were presumably surrounded by a semipermeable membrane, and could be liberated in a soluble form by mechanical trauma. Since the macrophage is an actively phagocytic cell, it was of some interest to examine the fate of these organelles and their contents following the uptake of particulate material. This communication will describe both biochemical and morphological events following the ingestion of microorganisms by BCGinduced alveolar macrophages.