Lactate: A key regulator of the immune response.

Lactate, the end product of both anaerobic and aerobic glycolysis in proliferating and growing cells-with the latter process known as the Warburg effect-is historically considered a mere waste product of cell and tissue metabolism. However, research over the past ten years has unveiled multifaceted functions of lactate that critically shape and impact cellular biology. Beyond serving as a fuel source, lactate is now known to influence gene expression through histone modification and to function as a signaling molecule that impacts a wide range of cellular activities. These properties have been particularly studied in the context of both adaptive and innate immune responses. Here, we review the diverse roles of lactate in the regulation of the immune system during homeostasis and disease pathogenesis (including cancer, infection, cardiovascular diseases, and autoimmunity). Furthermore, we describe recently proposed therapeutic interventions for manipulating lactate metabolism in human diseases.