T Cell Activation Depends on Extracellular Alanine (Cell Reports)

In health, T lymphocytes are in a resting state. However, stimulation with their cognate antigen induces massive growth and proliferation. Ron-Harel et al. demonstrate that T cells rely on extracellular alanine for activation. Consumed alanine is used primarily for protein synthesis, and alanine deprivation inhibits T cell metabolism and effector functions.