Epithelial Cell Gene Expression Induced by IntracellularStaphylococcus aureus
HEp-2 cell monolayers were cocultured with intracellularStaphylococcus aureus, and changes in gene expression were profiled using DNA microarrays. IntracellularS. aureusaffected genes involved in cellular stress responses, signal transduction, inflammation, apoptosis, fibrosis, and cholesterol biosynthesis. Transcription of stress response and signal transduction-related genes includingatf3, sgk, map2k1, map2k3, arhb, andarhewas increased. In addition, elevated transcription of proinflammatory genes was observed fortnfa, il1b, il6, il8, cxcl1, ccl20, cox2,andpai1. Genes involved in proapoptosis and fibrosis were also affected at transcriptional level by intracellularS. aureus. Notably, intracellularS. aureusinduced strong transcriptional down-regulation of several cholesterol biosynthesis genes. These results suggest that epithelial cells respond to intracellularS. aureusby inducing genes affecting immunity and in repairing damage caused by the organism, and are consistent with the possibility that the organism exploits an intracellular environment to subvert host immunity and promote colonization.