Supplementary Material for: Actin and Phosphoinositide Recruitment to Fully Formed <i>Candida albicans </i>Phagosomes in Mouse Macrophages

<i>Candida albicans</i> is a dimorphic yeast that enters macrophages (Mφ) via the β-glucan receptor dectin-1. Phagocytosis of <i>C. albicans</i> is characterized by actin polymerization, Syk kinase activation and rapid acquisition of phagolysosomal markers. In mice, <i>C. albicans</i> are able to resist the harsh environment of the phagosome and form pseudohyphae inside the phagolysosomal compartment, eventually extending from the Mφ. In this study, we investigated these unique <i>C. albicans </i>phagosomes and found that actin localized dynamically around the phagosomes, before disintegrating. Membrane phosphoinositides, PI(4,5)P<sub>2</sub>, PI(3,4,5)P<sub>3</sub>, PI(3,4)P<sub>2</sub>, and PI(3)P also localized to the phagosomes. Localization was not related to actin polymerization, and inhibitor studies showed that polymerization of actin on the <i>C. albicans</i> phagosome was independent of PI3K. The ability of mature <i>C. albicans</i> phagosomes to stimulate actin polymerization could facilitate the escape of the growing yeast from the Mφ.