EPAS1 regulates host antibacterial defense in response to bacterial quorum sensing

Hypoxia-inducible factors (HIFs) are a family of transcription factors that function as sensors of hypoxia. However, it remains unclear whether and how HIFs modulate host immunity by responding to other ligands. Here, we describe an immune regulatory function of HIF-2 (also known as EPAS1) in response to cis-2-dodecenoic acid (BDSF), a quorum sensing (QS) signal, secreted by Burkholderia cenocepacia. Upon ligand binding, EPAS1 activation leads to the production of inflammatory cytokines and the initiation of antibacterial defense. Inoculation with diffusible BDSF or liposome-encapsulated BDSF improves survival in mice infected with B. cenocepacia or Acinetobacter baumannii by preconditioning the immune system. Our findings reveal a previously unidentified role of EPAS1 as an intracellular pattern recognition receptor (PRR) for bacterial QS signal to control host antibacterial defense.