The aim of the proposed research is to study the fate of Zoopathogenic fungi within mammalian phagocytes and to gain some insight into the mechanism whereby such cells inhibit or kill intracellular parasites. The following fungus-host cell interactions will be examined by means of viability testing and studies of macromolecular synthesis: (1) mechanism of growth inhibition of Histoplasma capsulatum in macrophages activated by immune lymphocytes, (2) recovery of antifungal activity from disrupted phagocytic cells, (3) comparison of the intracellular fate of Candida albicans, H. capsulatum, and Torulopsis glabrata in neutrophiles, (4) comparison of fate of H. capsulatum within macrophages activated by fungal immunization with those activated by bacterial immunization, (5) mechanism of growth inhibition of T. glabrata within normal macrophages.