HIF-1α as a central mediator of cellular resistance to intracellular pathogens

Hypoxia-inducible transcription factor-1 alpha (HIF-1 alpha) was originally identified as a master regulator of cellular responses to hypoxia. More recently, HIF-1 alpha has emerged as a critical regulator of immune cell function that couples shifts in cellular metabolism to cell type-specific transcriptional outputs. Activation of macrophages with inflammatory stimuli leads to induction of the metabolic program aerobic glycolysis and to HIF-1 alpha stabilization, which reinforce one another in a positive feedback loop that helps drive macrophage activation. This activation of aerobic glycolysis and HIF-1 alpha is important both for production of inflammatory cytokines, such as IL-1 beta, and for cell intrinsic control of infection. Here, we review the importance of HIF-1 alpha for control of bacterial, fungal, and protozoan intracellular pathogens, highlighting recent findings that reveal mechanisms by which HIF-1 alpha is activated during infection and how HIF-1 alpha coordinates antimicrobial responses of macrophages.