Abstract
Migration of T cells is essential for their ability to mount immune responses. Chemokine-induced T cell migration requires WNK1, a kinase that regulates ion influx into the cell. However, it is not known why ion entry is necessary for T cell movement. We show that signaling from the chemokine receptor CCR7 leads to activation of WNK1 and its downstream pathway at the leading edge of migrating CD4+ T cells, leading to ion influx and consequent water entry by osmosis through AQP3. This WNK1-induced water entry is required to swell the membrane at the leading edge, generating space into which actin filaments can polymerize, thereby facilitating forward movement of the cell.
One Sentence Summary Chemokine-induced migration of T cells requires water entry at the leading edge to facilitate actin polymerization.
Competing Interest Statement
The authors have declared no competing interest.