SLFN2 protection of tRNAs from stress-induced cleavage is essential for T cell–mediated immunity

A T cell sleeper agent against stress Considerable changes in cellular metabolism occur when T cells transition from a resting to an activated state. One side effect of this process is an increase in reactive oxygen species (ROS). These molecules potentiate T cell receptor (TCR) signaling but can also result in detrimental oxidative stress (see the Perspective by Su and Dutta). Yueet al. describe one mechanism by which T cells can resolve this contradiction. Using mice with a T cell-specific deficiency in Schlafen 2 (SLFN2), they found that this protein binds to and protects transfer RNAs from oxidative stress-induced cleavage by the ribonuclease angiogenin. This process is downstream of ROS generation, which allows activated T cells to maintain protein synthesis despite the ROS that would otherwise inhibit translation.Science , this issue p.eaba4220 ; see also p.683