Space and Time in Leukocyte Migration

Abstract

Dendritic cells (DCs) are an essential component of the mammalian immune system because they link the innate and the adaptive immune responses. They are sentinels that patrol and scan the peripheral tissue where they capture pathogen-derived antigens at the site of infection. After this, they migrate to the secondary lymphoid organs, where they prime naive T lymphocytes by presenting the captured antigens. For migration towards the lymphoid organs, DCs make use of chemoattractant cues. They detect the distribution of the chemoattractant in the tissue and extend cellular protrusions (lamellipodia) to migrate up the chemical gradient in a process called chemotaxis. Although several of the molecular components for DC chemotaxis have been identified, little is known about the mechanisms used by DCs to sense gradients. We used a microfluidic chemotaxis chamber and optical microscopy to elucidate the gradient sensing mechanism of DCs. The microfluidic chemotaxis assay allows us to control with high precision the properties of the gradient in space and time. We will present several novel features of DC migration in response to different spatio-temporal stimulation patterns.