The Role of Macrophages in Candida albicansInfection In Vitro

Abstract

Mouse peritoneal macrophages cultivated in vitro were infected with Candida albicaus. The uptake of 3H-uridine and 3H-leucine as well as morphological changes in macrophages and fungus cells were studied by autoradiography. Phagocytized fungus cells remained in the yeast form and showed no activity toward incorporating 3H-uridine and 3H-leucine for 2 hr after infection. Cells not phagocytized began to produce germ tubes and actively incorporated both labeled precursors. Fungus cells within the macrophages produced germ tubes after 3 hr, some of which ruptured the host cells, then grew pseudohyphae and true hyphae. The uptake of both precursors was vigorous in candidal elements, but decreased in macrophages. Networks of long candidal filaments appeared 4 hr after infection and macrophages seemed to be degenerating with severely damaged synthesizing activities. When growth of C. albicans was compared in four different media, one with macrophages and the other three without macrophages, much more mycelial growth was obtained in the medium in which macrophages were present than in media without macrophages. From these results the role of macrophages in Candida infection was discussed.