Leukocyte Trafficking (None)

Leukocyte trafficking refers to the highly regulated process by which white blood cells (leukocytes) move throughout the body. This movement is essential for immune surveillance, homeostasis, and response to infection or injury. The process involves multiple steps: leukocytes exit the bone marrow, circulate in the blood and lymphatic systems, migrate into tissues during steady-state conditions or inflammation, and return via lymphatics or re-enter circulation. It is orchestrated through a cascade involving capture & rolling, activation, adhesion, crawling & transmigration (diapedesis), involving key molecules such as selectins, integrins, chemokines/chemokine receptors, and ICAMs/VCAMs. Dysregulation contributes to chronic inflammatory diseases, autoimmune disorders, cancer metastasis, and graft-versus-host disease.

Not applicable for a biological process; however, therapies targeting components of the process (e.g., integrins) act by blocking adhesion and transmigration of leukocytes.