A detailed study led by Ana Traven (Monash University, Australia) sheds new light on the mechanisms by which clinically-important fungal infections such as C albicans are able to evade the host immune system that leads to an inflammasome-dependent host cell death (pyroptosis) of macrophages.
Amongst their investigations was an elegant live-microscopy analysis to model the inhibition of this process. Macrophages with an inflammasome protein (ASC) tagged with Cerulean fluorescent protein were exposed to C albicans and then monitored for inflammasome-triggering and consequent pyroptosis. Cell death was monitored by the presence of the far-red viability probe DRAQ7 over 24 hours of time-lapse imaging. Dead cells become permeabilised and DRAQ7 brightly labels the nuclei. Co-localisation of an inflammasome cerulean "speck" and DRAQ7 nucleus infers the conclusion of the pyroptosis while cells with solely the bright cerulean "speck" denotes a macrophage with activated inflammasome but not yet dead.
Tucey TM, Verma-Gaur J, Nguyen J, Hewitt VL, Lo TL, Shingu-Vazquez M, Robertson AA, Hill JR, Pettolino FA, Beddoe T, Cooper MA. The Endoplasmic Reticulum-Mitochondrion Tether ERMES Orchestrates Fungal Immune Evasion, Illuminating Inflammasome Responses to Hyphal Signals. mSphere. 2016 Jun 22;1(3):e00074-16.
