Figure 7.

S. aureus within neutrophils is targeted by selective autophagy receptor Sqstm1. (A and B) Confocal photomicrographs of Sqstm1-mediated response at 1 hpi in live lyz:GFP-Sqstm1 embryos infected with mCherry-labeled S. aureus. The fusion GFP-Sqstm1 protein colocalizes with intracellular bacteria (A) or with apparent vesicles containing the bacteria (B). The images shown are representative of three independent experiments. Scale bars: 10 µm. (C) Quantification of Sqstm1 associations with intracellular S. aureus at 2 hpi within neutrophils of live lyz:GFP-Sqstm1 embryos infected with approximately 1500 CFU of live or heat-killed mCherry-labeled S. aureus. Data are shown as mean ± standard deviation (SD) obtained from three independent experiments (5–6 larvae per group per experiment). 109 infected neutrophils in 18 larvae injected with live bacteria were analyzed. 101 infected neutrophils in 17 larvae injected with heat-killed bacteria were analyzed. Unpaired two-tailed t-test was used. **** P < 0.0001