Neutrophil calcium flux and chemotaxis

Neutrophil calcium (Ca2+) flux and chemotaxis are essential physiological processes that drive the recruitment of neutrophils to sites of infection and tissue injury. These responses are typically initiated by the binding of chemoattractants, such as interleukin-8 (IL-8) or formyl-methionyl-leucyl-phenylalanine (fMLP), to specific G protein-coupled receptors (GPCRs) on the neutrophil surface [6, 14]. This ligation triggers a signaling cascade involving phospholipase C (PLC) and phosphoinositide 3-kinase (PI3K), leading to a rapid increase in intracellular calcium levels through both internal release and store-operated calcium entry (SOCE) [5, 13]. The resulting Ca2+ flux is a critical second messenger that synchronizes actin polymerization and integrin activation, enabling the cell to polarize and migrate along chemical gradients [14, 15]. While vital for host defense, excessive neutrophil chemotaxis is a primary driver of tissue damage in chronic inflammatory diseases like chronic obstructive pulmonary disease (COPD), rheumatoid arthritis, and severe asthma [3, 12]. Consequently, these processes are frequently targeted in drug discovery using antagonists of receptors like CXCR1 and CXCR2, or inhibitors of downstream signaling components [3, 4]. Monitoring Ca2+ flux and chemotactic speed serves as a key functional readout for evaluating the efficacy of anti-inflammatory therapeutics [12, 16].

Other names

Neutrophil activationNeutrophil migrationCalcium mobilizationChemotactic responseDirected neutrophil recruitment

Inhibition of chemoattractant receptors (GPCRs) or downstream signaling enzymes (e.g., PI3K, PLC) prevents the mobilization of intracellular calcium and the reorganization of the actin cytoskeleton, thereby blocking directed cellular movement.