Growth inhibition of Blastomyces dermatitidis in alveolar and peripheral macrophages from patients with blastomycosis.

Blastomyces dermatitidis evokes a pyogranulomatous disorder with organisms frequently found inside giant cells. Macrophages from bronchoalveolar lavage fluid and peripheral blood in monolayer cell cultures were challenged with live yeast organisms to examine phagocytosis and intracellular growth. A greater number of macrophages from patients recovering from blastomycosis had phagocytized Blastomyces compared with macrophages from healthy control donors. No differences were detected within the groups between alveolar and peripheral macrophages. Intracellular growth of the fungus was reduced in cultures of both cell types from patients compared with those from control subjects. Supernatants from specific Blastomyces antigen-stimulated lymphocyte cultures were collected, and treatment with the supernatant to control donors' macrophages resulted in increased phagocytosis and inhibition of intracellular growth. Antigen-induced lymphocyte stimulation as a correlate of cellular immunity is qualitatively related to alveolar or peripheral macrophage phagocytosis and growth inhibition of this fungus.