Understanding Molecules that Mediate Leukocyte Extravasation

Purpose of Review: Getting leukocytes to the site of inflammation is extremely important for maintaining homeostasis. Over time, leukocyte extravasation is resolved; however, in the case of chronic inflammatory diseases, it is not. When left unresolved, persistent leukocyte infiltration is detrimental to the host. Understanding how leukocytes get out of circulation and into the tissue puts us closer to combating these diseases. This review focuses on the molecules regulating leukocyte extravasation. Recent Findings: There are multiple pathways regulating leukocyte transmigration. Targeted recycling of membrane from the lateral border recycling compartment is required for leukocyte extravasation. Differences in leukocyte phenotypes may contribute to different transmigration rates and extent. Summary: Leukocyte transmigration is regulated by a multitude of molecules. How these molecules interact to coordinate the process is the subject of ongoing research. Characterization of these pathways will be useful in developing therapies for chronic inflammation.