Fig. 2

Metabolic features of different CD8+ T cells. This figure depicts the distinct metabolic characteristics of CD8+ T cells in different states. Naïve CD8+ T cells are metabolically quiescent and take up minimal amounts of glucose and lipids to maintain their slow metabolic activities. These cells primarily derive their energy from the TCA cycle, with OXPHOS playing a significant role. Upon activation, effector CD8+ T cells become highly metabolically active and increase their mitochondrial activities. To meet the increased energy demands for proliferation and effector functions, these cells increase their uptake of glucose and lipids. Effector CD8+ T cells rely primarily on glycolysis and OXPHOS for energy production, sustaining their rapid growth and cytotoxic activities. In the tumor microenvironment, CD8+ T cells often become exhausted, resulting in impaired metabolism. Exhausted CD8+ T cells have reduced activities in both the TCA cycle and OXPHOS, relying predominantly on FAO to meet their energy needs