Abstract
Naïve T cells contact dendritic cells (DCs) presenting antigen in lymph nodes to become activated. T cell motility is a key step to enabling T-DC interactions by bringing T cells into close proximity with DCs. We find a novel role for interleukin 7 (IL-7) in regulating T cell motility in lymph nodes. We show using 2 photon microscopy that IL-7 promotes T cell speed and increases the search area for individual T cells. Downstream of IL-7R, IL-7-mediated T cell motion required JAK/STAT activation, but IL-7R-mediated T cell motility occurred independently of mTOR signaling. Inhibition of IL-7-IL-7R signaling resulted in reduced contact with DCs in the T cell zone of the lymph node. Using computational modeling, we show IL-7-IL-7R is specifically important for T cell contacts with unique DCs. Our results show a new role for IL-7-IL-7R in regulating T cell function by controlling T cell motility in the lymph node. Thus, IL-7-IL-7R axis promotes not only T cell development, survival, and proliferation, but also T cell motion, leading to enhanced T cell interaction with DCs.
