HIF-1α Is Essential for Myeloid Cell-Mediated Inflammation

AbstractGranulocytes and monocytes/macrophages of the myeloid lineage are the chief cellular agents of innate immunity. Here, we have examined the inflammatory response in mice with conditional knockouts of the hypoxia responsive transcription factor HIF-1α, its negative regulator VHL, and a known downstream target, VEGF. We find that activation of HIF-1α is essential for myeloid cell infiltration and activation in vivo through a mechanism independent of VEGF. Loss of VHL leads to a large increase in acute inflammatory responses. Our results show that HIF-1α is essential for the regulation of glycolytic capacity in myeloid cells: when HIF-1α is absent, the cellular ATP pool is drastically reduced. The metabolic defect results in profound impairment of myeloid cell aggregation, motility, invasiveness, and bacterial killing. This role for HIF-1α demonstrates its direct regulation of survival and function in the inflammatory microenvironment