Abstract
Human peripheral blood monocytes readily phagocytized Coccidioides immitis endospores (2 to 5 microns) in vitro. Within 24 to 30 h at 37 degrees C, the phagocytized endospores started developing into immature spherules. However, when the monocytes were incubated with recombinant human gamma interferon (rIFN-gamma) or recombinant human tumor necrosis factor alpha (rTNF-alpha) and then infected, fewer endospores developed into spherules. Treatment with rIFN-gamma or rTNF-alpha activated the fungicidal capabilities of the monocytes as evidenced by the significant reduction in CFU that could be recovered from rIFN-gamma- or rTNF-alpha-activated monocytes compared with nontreated controls.