bioRxiv. 2023 Sep 26. pii: 2023.09.25.559385. [Epub ahead of print]
Emily C Britt,
Xin Qing,
James A Votava,
Jorgo Lika,
Andrew Wagner,
Simone Shen,
Nicholas L Arp,
Hamidullah Khan,
Stefan M Schieke,
Christopher D Fletcher,
Anna Huttenlocher,
Jing Fan.
Neutrophils are the first responders in innate immunity. Neutrophils can perform a variety of effector functions which are associated with specific metabolic demand. The utilization of various metabolic sources, including extracellular glucose, intracellular glycogen, and other alternative substrates, have been found critical for neutrophil fitness and functions in recent studies. However, the quantitative contribution of these nutrients under specific conditions and the relative dependence of various cell functions on specific nutrients remain unclear. Here using ex vivo and in vivo isotopic tracing, we revealed that under resting condition, human peripheral blood neutrophils, in contrast to in vitro cultured human neutrophil-like cell lines, rely on glycogen as a major direct source of glycolysis and pentose phosphate pathway. Extracellular glucose contributes slightly less than half, and other sources have minor contributions. Upon activation with a diversity of stimuli (including zymosan A, TNFα, PMA, LPS, or Pseudomonas aeruginosa ), neutrophils undergo a significant nutrient preference shift, with glucose becoming the dominant metabolic source. The shift to glucose utilization is often rapid and driven by multi-fold increases in glucose uptake, which is mechanistically mediated by the phosphorylation and translocation of GLUT1. At the same time, cycling between gross glycogenesis and glycogenolysis is also substantially increased, while the net flux favors sustained or increased glycogen storage. Different effector functions of activated neutrophils have specific nutrient dependence. The oxidative burst is most dependent on extracellular glucose, while the release of neutrophil extracellular traps can be flexibly supported by either glucose or glycogen utilization. Shifting neutrophil away from glycogen utilization increases migration and fungal control. Together, these results quantitatively characterize fundamental features of neutrophil metabolism and elucidate how metabolic remodeling supports and shapes neutrophil functions upon activation.