(A) GFP-LC3 CHO cells were preincubated with 1 mM dybutiryl cAMP (+dbcAMP) for 30 min and then were infected for 4 h in the presence of db cAMP with the wt strain of S. aureus (wt), the mutant deficient for α-hemolysin (Hla−), or the Hla(−) mutant expressing an α-hemolysin plasmid (Hla(−) +pHla). Cells without any treatment were used as control (−dbcAMP). The nucleus and the bacteria were labeled with TOPRO as indicated in Materials and Methods, and immediately visualized by confocal microscopy. Images are representative of two independent experiments. 