Stromal infrastructure of the lymph node and coordination of immunity

•Lymph node stromal cell populations are heterogeneous and functionally versatile.•LN stromal cells provide the infrastructure necessary to sustain immune cell homeostasis.•They direct precise immune cell migration and positioning via spatiotemporal cues.•Dynamic mechanisms govern LN stromal cells during homeostasis and active immunity.

The initiation of adaptive immune responses depends upon the careful maneuvering of lymphocytes and antigen into and within strategically placed lymph nodes (LNs). Non-hematopoietic stromal cells form the cellular infrastructure that directs this process. Once regarded as merely structural features of lymphoid tissues, these cells are now appreciated as essential regulators of immune cell trafficking, fluid flow, and LN homeostasis. Recent advances in the identification and in vivo targeting of specific stromal populations have resulted in striking new insights to the function of stromal cells and reveal a level of complexity previously unrealized. We discuss here recent discoveries that highlight the pivotal role that stromal cells play in orchestrating immune cell homeostasis and adaptive immunity.