Defining the roles of Ca²⁺ signals during T cell activation

Ca²⁺ signaling is critical to T cell activation as a means of rapidly activating and integrating numerous signaling pathways to generate widespread changes in T cell gene expression and function. Ca²⁺ is a second messenger that functions by binding to and altering the function of key proteins leading to pleiotropic changes in cell function. Study of this unique signaling realm has been facilitated by numerous specialized tools including electrophysiological techniques, chemical and genetically designed Ca²⁺ indicators, Ca²⁺ sensors for downstream signaling, and genetically modified mouse models defective in specific Ca²⁺ signaling pathways. Here, we discuss how these techniques have and can be used for the study of T cell responses.