Figure 3. Cell-extrinsic and -intrinsic generation of oscillatory immune responses.

(A) Rhythmic oscillations in entrainment cues regulate homeostatic trafficking of hematopoietic stem cells and leukocytes. The SNS is the central entrainment cue that controls expression of chemokines and adhesion molecules in stromal cells, such as bone marrow stromal cells and endothelial cells, which imparts rhythmicity to trafficking of hematopoietic stem cells and leukocytes.

(B) Cell-intrinsic clocks regulate basal and inducible programs in myeloid cells for maintenance of local homeostasis.