Sugar, fat, and protein: new insights into what T cells crave

T cell activation and differentiation is a complex process that has evolved beyond the two-signal model to a number of varied and opposing inputs that must be interpreted to make a cell fate decision. While stimulation through the TCR, costimulatory, and cytokine receptors is required, metabolic signaling has emerged not only as an activation signal, but also one that can influence and shape differentiation. Recent findings have revealed unappreciated roles for glucose, fatty acids, and salt in the function of many T cell subsets. In this review, we will highlight the latest advances in the burgeoning field of immunometabolism, focusing on how the menu of T cell fuels has expanded.