Fig. 1

Lung epithelial cells secrete CCL20 to recruit CCR6-expressing cells. Glycosaminoglycans (GAGs) are present on the surface of lung epithelial cells. Upon stimulation, these cells secrete large amounts of CCL20. GAGs bind to CCL20 and anchor it to the cell surface. This accumulation of CCL20 creates a concentration gradient within the extracellular matrix, recruiting CCR6-expressing cells. CCR6 contains a molecular switch that remains closed in the absence of CCL20. However, upon CCL20 binding, CCR6 couples with downstream G proteins, activating signaling pathways that mediate cellular responses