Growth inhibition of Candida albicans by rabbit alveolar macrophages.

Normal rabbit alveolar macrophages were infected in vitro with Candida albicans. Early after infection, germ tube formation of phagocytized C. albicans was inhibited in contrast to extracellular (nonphagocytized) C. albicans. Over and 8-h period, plate counts of C. albicans incubated with alveolar macrophages revealed a decrease in colony-forming units in contrast to C. albicans alone. In addition, an assay was developed which specifically measured C. albicans [3H]leucine incorporation in the presence of alveolar macrophages. Using this assay, we observed a 71 to 93% inhibition of macromolecular synthesis in C. albicans when incubated with alveolar macrophages. Autoradiographic studies showed that the inhibition of leucine incorporation was restricted to the ingested Candida.