Leukocyte chemotaxis

Leukocyte chemotaxis is the directed movement of white blood cells (leukocytes) toward a chemical gradient, such as chemokines, bacterial products, or complement components. This process is a fundamental component of the innate and adaptive immune systems, enabling immune cells like neutrophils, monocytes, and lymphocytes to reach sites of infection, injury, or inflammation. The process is initiated by the binding of chemoattractants to specific cell-surface receptors, primarily G-protein-coupled receptors (GPCRs), which activates complex intracellular signaling cascades—including the PI3K and phospholipase pathways—to drive actin cytoskeleton rearrangement and cellular polarization. While vital for effective host defense, dysregulated or excessive leukocyte chemotaxis contributes significantly to the pathogenesis of chronic inflammatory conditions, autoimmune diseases, and cancer metastasis. Consequently, many modern therapeutic strategies target the specific molecular components of the chemotactic machinery, such as chemokine receptors and integrins, to modulate the inflammatory response and prevent pathological tissue infiltration.

Other names

Directed leukocyte migrationWhite blood cell chemotaxisLeukocyte traffickingLeukotaxisChemotactic response

Drugs modulate leukocyte chemotaxis by antagonizing specific chemokine receptors (e.g., CCR5, CXCR4) to prevent gradient sensing, blocking integrin-mediated adhesion to the vascular endothelium (e.g., α4β7 integrin), or inhibiting downstream signaling enzymes and cytoskeletal regulators required for cell motility.