Chapter 15. A microfluidics-based method for chemoattractant gradients.

Leukocyte trafficking in tissues mediates cellular immune responses and can be directed by chemotactic factors such as chemokines. Understanding chemotactic responses of leukocytes to chemoattractant gradients is of great interest and importance to both basic science and clinical research. Conventional methods for studying leukocyte migration and chemotaxis generally lack the ability to maintain and manipulate gradient profiles. In contrast, microfluidic devices can generate well-defined stable chemical gradients and can precisely modify gradient conditions in space and time. Previously, microfluidic gradient-generating devices have been used to investigate various aspects of leukocyte migration in different chemoattractant fields with the focus on human blood neutrophils. Recently, chemotaxis of human blood T cells in chemokine gradients was successfully demonstrated in a microfluidic device. In this chapter, the detailed method of analyzing the migration of human blood neutrophils and T cells in chemoattractant gradients with microfluidic devices is described.