The Perfect Swarm
Directed Migration of Neutrophil-Like Cells through Engineered Chemokine Secretion
Cell coordination within a population depends on the ability of individual cells to accurately receive and respond to extracellular stimuli from both the environment and neighboring cells. Coordinating cellular motility, where cells move in response to external cues, is central to many physiological responses. For example, human neutrophils demonstrate migratory behavior towards chemokine gradients as part of the adaptive immune system. Here, we present a mechanism to harness cellular chemotaxis as a means of controlling cellular swarming and directed movement. We engineered human embryonic kidney (HEK) cells to secrete chemokines that induce chemotaxis in unengineered neutrophils. To evaluate neutrophil chemotaxis, we first differentiated HL-60 progenitor cells into chemotactic motile cells. We then introduced these motile cells to chemokines produced by our engineered HEK cells and evaluated their movement utilizing a series of cellular migration assays. We anticipate our engineered system will provide insight into how immune systems develop as well as form a preliminary toolbox for recruiting mammalian cells selectively in tissue engineering applications.