Effects of lactate on metabolism and differentiation of CD4T cells.

Background: Lactate accumulation caused by abnormal tumor metabolism can induce the formation of an inhibitory immune microenvironment through a variety of pathways, which is characterized by regulatory T cells (Treg) infiltration and effector T cells (Teff) depletion. Studies have found that the key reason why Treg cells can survive in harsh environments lies in their flexible metabolic mode, which can use lactate in tumor microenvironment (TME) as an alternative energy substance to maintain their inhibitory activity. In addition, lactate could also promote the differentiation of CD4T cells into Treg, but the mechanism was not completely clear.