FIG. 5.
Frequency of coiling phagocytosis observed with L. major, T. cruzi, and C. albicans. Human peripheral blood monocytes (PBM) and resident (RPM) or thioglycolate-elicited (PEM) macrophages from the peritoneal cavities of mice (2 × 106 each) were incubated with either L. major promastigotes, T. cruzi trypomastigotes, or C. albicans hyphae (2 × 107 each) in the presence of fFCS for 30 min. Phagocytosis was evaluated by electron microscopy of randomly chosen ultrathin sections. The bars represent the relative frequencies of coiling phagocytosis, given as mean ± SEM of duplicate determinations in a typical experiment. Essentially the same results were observed in additional two experiments using phagocytes from different donors and animals. The majority of the L. major promastigotes are engulfed via pseudopod coils by all phagocyte populations, whereas this is a very rare event with T. cruzi trypomastigotes. Coiling phagocytosis is only occasionally observed with C. albicans hyphae by PBM and RPM but not by PEM.