Tissue-resident memory T cells live off the fat of the land

Abstract

The consumption of exogenous free fatty acids by tissue-resident memory T (Trm) cells is critical for their long-term survival and antiviral function, and appears to be a conserved feature of Trm cells in both mouse and man, a recent paper published in Nature demonstrates.

Figure 1

Left, Endogenous lipid metabolism in circulating memory T cells. (A) Basal glucose uptake and glycolysis drives TCA cycle progression. (B) TCA cycle intermediates are utilized for de novo lipid synthesis. (C) IL-7 signaling supports aquaporin-mediated import of glycerol used in the synthesis of triacylglycerol. (D) Triacylglycerol is the predominant substrate for mitochondrial β-oxidation driving OXPHOS in circulating memory T cells. Right, Exogenous fatty acid utilization by T_rm cells. (1) Expression of the lipid scavenger receptor CD36 encourages the uptake of exogenous FFAs. (2) FABP4/5 are necessary for the internalization and processing of exogenous FFAs used for OXPHOS (3). (4) Constitutive expression of Pparγ supports exogenous lipid metabolism in T_rm cells in part through promoting Fabp4/5 expression.