Regulation of neutrophilic inflammation by the HIF/PHD pathway.

I propose that differential expression of HIF/PHD isoforms regulates neutrophil function and metabolism. Our key goals are to 1. Define the roles of hypoxia, inflammatory cytokines and microbes in the selective regulation of HIF/PHD pathway components and neutrophil polarisation. This will comprise the characterisation of relative expression of HIF1 and HIF2 in un-stimulated and inflammatory neutrophils, and their relationship to microbial killing and co-ordinated pro-inflammatory responses. The dominance of PHD3 over other PHD isoforms in regulating neutrophil survival will be addressed using in vivo models of neutrophilic inflammation, with the catalytic requirement and HIF dependence of this hypoxic survival response determined using stem cell derived neutrophil cell lines. 2. Determine whether direct regulation of neutrophil metabolism is central to hypoxic survival and the importance of the HIF/PHD pathway in co-ordinating this response. We will firstly characterise neutroph il metabolic flux in resting and activated neutrophils, before dissecting the importance of glucose / glutamine pathways in the regulation of neutrophil survival responses in vitro and how they modulate the outcomes of neutrophilic inflammation in vivo. 3. Translate the importance of metabolic and functional neutrophil regulation by the HIF/PHD pathway to in vivo models of acute and chronic lung infection.