TABLE 1.

Metabolism and function of immune cells

Immune cell lineage	Subtypes	Function	Metabolism
Macrophage
	M1 (classical activation)	Pathogen clearance and antigen presentation Secretes pro‐inflammatory cytokines and express high levels of MHC	Enhanced glycolysis, PPP, and FA synthesis
	M2 (alternate activation)	Produce anti‐inflammatory cytokines to promote immunosuppression and tumor progression	Increased OXPHOS and FAO decreased glycolysis and PPP
Neutrophil			Glycolysis If exposed to a TME deficient in glucose, adapt to mitochondrial FAO
	N1 (anti‐tumor)	Anti‐tumor polarization induced by type 1 IFNs
	N2 (pro‐tumor)	TGF‐β an overexpressed by tumor cells polarize neutrophils to pro‐tumor phenotype
	Neutrophil extracellular traps (NETs)	Fibers of decondensed DNA	Dependent on glucose and to a lesser extent on glutamine
NK cell		Critical in the early immune response regulating the adaptive immune response through the release of IFN‐γ	Use OXPHOS during their resting state and upon short‐term activation Prolonged stimulation: switch to glycolysis
T cell
	CD4+ Helper T cells	Mediator of immune function secreting cytokines to heighten immune response	Glycolysis and ACC‐mediated de novo FA synthesis
	CD8+ Cytotoxic T cells	Direct cytotoxic killing of cancer cells	Enhanced glycolysis, glutaminolysis, and FAO to exert anti‐tumor cytotoxicity
	Regulatory T cells	Dampen the immune response	FAO rather than glycolysis
	Memory T cells	Protection against reinfection or tumor re‐emergence	Mitochondrial FAO for development and long‐term survival