Adenosine triphosphate acts as a paracrine signaling molecule to reduce the motility of T cells

Organization of immune responses requires exchange of information between cells. This is achieved through either direct cell–cell contacts and establishment of temporary synapses or the release of soluble factors, such as cytokines and chemokines. Here we show a novel form of cell‐to‐cell communication based on adenosine triphosphate (ATP). ATP released by stimulated T cells induces P2X4/P2X7‐mediated calcium waves in the neighboring lymphocytes. Our data obtained in lymph node slices suggest that, during T‐cell priming, ATP acts as a paracrine messenger to reduce the motility of lymphocytes and that this may be relevant to allow optimal tissue scanning by T cells.