Figure 1.

Metabolic pathways of neutrophils and macrophages. Macrophages and neutrophils utilize their differing metabolic capacities to maintain their effector function. In short lived, rapidly responding neutrophils, glucose is rapidly processed to form ATP via glycolysis and NADPH via the pentose phosphate pathway. These activities enable neutrophils to engage in chemotaxis, phagocytose and maintain respiratory burst via NADPH. Neutrophil NOX can be associated with the plasma membrane, rather than the mitochondria. This glucose‐maintained NADPH source is important for many ROS related functions such as NET formation; however fatty acid and glutamine fueled mitochondrial function has also been demonstrated to play a significant role in NET formation and the maintenance of ROS when glucose availability or NOX function is limited. Neutrophils also build and utilize glycogen, possibly to further aid function in glucose‐depleted environments. Macrophages are also able to process glucose via glycolysis and the pentose phosphate pathway to maintain ATP and NADPH respectively. ATP‐stimulation of macrophages helps maintain mitochondrial membrane potential, cell viability and induces cytokine expression. As a longer‐lived cell, macrophages also contain significant mitochondrial capacity and utilize this to process glutamine and fatty acids. This mitochondrial capacity is enhanced during activation with IL‐4 and reduced under IFN‐γ and LPS stimulation in an NO‐dependent mechanism