Quantitative analysis of phagocytosis of Cryptococcus neoformans by adherent phagocytic cells by fluorescence multi-well plate reader

Macrophages and monocytes are adherent phagocytic cells which play an impor tant role in host defence against the yeast-like fungus Cryptococcus neofor mans. Before, phagocytosis by adherent phagocytes could only be measured by means of microscopy or by a radioactive assay, which both have obvious dis advantages. We have developed a new, rapid and objective method to measure phagocytosis of C. neoformans by adherent phagocytes (e.g. alveolar macroph ages) using a fluorescence multi-well plate reader. This method allows us t o discriminate accurately between adherence and internalisation of C. neofo rmans by macrophages during long term incubation. In addition, the method w as used to study the role of the mannose receptor in phagocytosis of the ac apsular yeast in the absence of serum by human monocyte-derived macrophages (MDM). (C) 2000 Elsevier Science B.V. All rights reserved.