The transcription factor BACH1 couples chromatin priming and repression to enable macrophage plasticity and adaptation.

BACH1 acts as a pioneer repressor, priming chromatin and regulating macrophage plasticity with 3D architecture constraints, crucial for tissue adaptation and inflammation responses.

• Why it matters: Understanding how macrophages adapt to inflammation and tissue changes is vital for developing therapies for inflammatory diseases and tissue repair, but the mechanisms controlling their transcriptional flexibility are unclear.
• What they did: The study used genomic and in vivo approaches to analyze BACH1 binding, chromatin interactions, and macrophage functions, revealing its dual role in chromatin priming and repression during activation.
• The result: BACH1's activity enables macrophages to rapidly respond to stimuli, with its deletion impairing polarization and tissue resilience, highlighting its key role in immune adaptability and potential therapeutic targeting.