Neutrophil-active chemokines in in vivo imaging of neutrophil trafficking.

Chemokines are proinflammatory mediators that regulate leukocyte trafficking at different steps of the leukocyte recruitment cascade. Studies using new imaging approaches and new mouse models are giving new insights into the role of chemokines in neutrophil migration at sites of inflammation. Conventional rolling and adhesion paradigms as well as previously unappreciated functions of signaling pathways triggering leukocyte adhesion, intralumenal crawling and transendothelial migration are compiled and described here. In this review we will summarize recent work in this field, highlighting in vivo imaging studies that examine the behavior of neutrophils in response to chemokines.