AUGMENTED INHIBITION OF GROWTH OF CANDIDA-ALBICANS BY NEUTROPHILS IN THE PRESENCE OF LACTOFERRIN

The combined inhibitory effects of neutrophils and lactoferrins on the growth of Candida albicans were examined. Murine or human neutrophils partially inhibited growth of C. albicans when cultured with C. albic ans in vitro. The growth inhibition was augmented by a combination of neutrophils and more than 30 mu g/ml of bovine lactoferrin or 1 mu g/m l of human lactoferrin, concentrations less than 1/10-1/200 their inhi biting concentrations when used alone. The inhibition of C. albicans w as also enhanced by combination of neutrophils and bovine apolactoferr in or iron-bound holo-lactoferrin, but not by transferrin. Combination effects of neutrophils and lactoferrin were also observed in a condit ion where there was no contact between neutrophils and Candida cells. These results suggest that neutrophils inhibit the growth of C. albica ns regardless of whether there is direct contact between them and Cand ida cells: neutrophil growth inhibition effects were augmented in the presence of a physiological concentration of lactoferrin, perhaps thro ugh some action of lactoferrin other than chelation of ferric ion.