Immunometabolism

Immunometabolism is a branch of biology that studies the interplay between metabolism and immunology in all organisms. In particular, immunometabolism is the study of the molecular and biochemical underpinninngs for i) the metabolic regulation of immune function, and ii) the regulation of metabolism by molecules and cells of the immune system. Further categorization includes i) systemic immunometabolism and ii) cellular immunometabolism. Immunometabolism first appears in academic literature in 2011, where it is defined as "an emerging field of investigation at the interface between the historically distinct disciplines of immunology and metabolism." A later article defines immunometabolism as describing "the changes that occur in intracellular metabolic pathways in immune cells during activation". Broadly, immunometabolic research records the physiological functioning of the immune system in the context of different metabolic conditions in health and disease. These studies can cover molecular and cellular aspects of immune system function in vitro, in situ, and in vivo, under different metabolic conditions. For example, highly proliferative cells such as cancer cells and activating T cells undergo metabolic reprogramming, increasing glucose uptake to shift towards aerobic glycolysis during normoxia. While aerobic glycolysis is an inefficient pathway for ATP production in quiescent cells, this so-called “Warburg effect” supports the bioenergetic and biosynthetic needs of rapidly proliferating cells. There are many indispensable signalling molecules connected to metabolic processes, which play an important role in both the immune system homeostasis and in the immune response. From these the most significant are mammalian target of rapamycin (mTOR), liver kinase B1 (LBK1), 5' AMP-activated protein kinase (AMPK), phosphoinositide 3 kinase (PI3K) and protein kinase B (akt). All of the aforementioned molecules together control the most important metabolic pathways in cells like glycolysis, krebs cycle or oxidative phosphorylation.