Fig. 2.

Neutrophil mitochondria actively participate in phagocytosis of S. aureus

After inoculation with GFP-labelled S. aureus, PMN mitochondria are present at the leading edge of activated cells. A) Representative 3D image series captured from Supplementary Video 1. B) Representative 2D image captured immediately after inoculation of MitoTracker Deep-Red-loaded PMN with GFP-S. aureus, captured at 25 μm scale. C) Representative 2D image series illustrating a 25-frame tile-scan image, captured at 100 μm scale (left), 25 μm scale (center), and 5 μm scale (right). Phagocytosis was quantified throughout time-course by generating an image ‘mask’ using the red mitochondrial signal and verifying PMN morphology using brightfield imaging. The total area of GFP-S. aureus contained within the image mask was measured in 10-min intervals for 30 min. D) Quantitation of total S. aureus area per PMN. Data are mean ± SEM of n = 7 patients; RM one-way ANOVA with Tukey post-test; *p < 0.05, **p < 0.01. For immunofluorescence: mitochondria (red), S. aureus (green), nuclei (blue). (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)