Interplay Between Metabolic Sensors and Immune Cell Signaling.

The immune system, like all other systems, responds to perturbations of the baseline, homeostatic functioning of immune cells. These perturbations come in the form of infection, tumors, autoantigens, and can occur after mismatched transplantation. During response, immune cells alter their metabolic activities. However, the subsets of the same cell type differ to distinctively associate specific immune function to a particular metabolic profile. The response is mounted as a joint function of metabolic receptor and immune receptor signaling that target various metabolic pathways: glycolysis the pentose phosphate pathway; oxidative phosphorylation; beta-oxidation of fatty acids and transamination. The products from these cycles are integrated in the tricarboxylic acid cycle. However, many more pathways lead to many secondary metabolites that are not directly related to energy derivation or maintaining structure of the cells. These secondary metabolites can again work in an autocrine manner to re-tune the immune cells to optimize their restorative effector functions.