Identification of Fra-1/AP-1 binding sites in macrophages

The polarization and activation of macrophages are controlled synergistically by transcription factors such as NF-κB and AP-1 transcription factor members. Surprisingly, little is known about the role of the AP-1 member, Fra-1, during macrophage responses. To determine the full spectrum of Fra-1 binding sites in macrophages, chromatin immunoprecipitation sequencing analysis was performed in macrophages pooling down for the transcription factor Fra-1. For ChIP analyses, peritoneal macrophages were collected by peritoneal lavage of 8-week-old C57Bl/6 (n=9). Peritoneal cells were plated over night. The next day, suspension cells were removed and adherent cells were stimulated for 1 h with 10 µg/mL LPS (n=3), apoptotic cells in a ratio of 1:5 (n=3) or left unstimulated (n=3).