FIG. 7.

Influence of LPS and PMA on the frequency of coiling phagocytosis of C. albicans. Untreated human peripheral blood monocytes (PBM; 2 × 10⁶) and PBM pretreated with LPS (1 μg/ml) and/or PMA (10 ng/ml) for 10 min were incubated with C. albicans hyphae (2 × 10⁷) in the presence of fFCS for another 30 min. Phagocytosis was evaluated in a blinded fashion by electron microscopy of randomly chosen ultrathin sections. The bars represent the normalized frequencies of coiling phagocytosis, expressed as mean ± SEM of three separate experiments with monocytes from different donors. Pretreatment of PBM with LPS abolished coiling phagocytosis of C. albicans hyphae. The effect of LPS could be neutralized by additional treatment with PMA, whereas PMA alone did not affect the frequency of coiling phagocytosis to a significant extent (∗, P < 0.05 in the χ² test).