FIG. 6.

Soluble melanin influences the ingestion of fungal cells by human or animal phagocytes. The indices of phagocytosis for F. pedrosoi conidia (A), sclerotic forms (B), or C. albicans organisms (C) by human neutrophils were expressed as a function of BCECF staining, as measured by flow cytometry. The interaction of F. pedrosoi conidia with mouse macrophages was evaluated microscopically after staining with Giemsa stain (D). Black bars, phagocytosis of fungal forms after interaction with phagocytes. The addition of soluble melanin (white bars) caused an increase in the phagocytosis levels in all systems. The influence of melanin antibodies alone (gray bars) or in association with melanin (hatched bars) on the phagocytosis of conidia (A) or sclerotic cells (B) was also evaluated. Values of P and statistical significance are described in Results. Data are expressed as means of three independent experiments ± standard deviations. Inset, representative sample of the interaction of BCECF-labeled conidia and human neutrophils.