Figure 3.

Shared mechanism of recruitment between intestine and articulation in AS. The ligand-receptor pair CCL20-CCR6 constitutes the predominant chemoattraction route of Th17 targeting both intestine and inflamed articulation. Emerging evidence has shown that both tissues express compatible adhesion molecules including VCAM-1, ICAM-1, and MAdCAM-1 for integrin binding, allowing Th17 cells to enter the inflammatory site. Mechanical stress remodeled ECM provides not only T cell stimulant, as the aforementioned hyaluronan and collagen fragment, but also fibronectin fragments that are able to bind and stimulate Th17 cells via integrin α4β1.