Oral keratinocytes synthesize CTACK : A new insight into the pathophysiology of the oral mucosa

The skin‐associated chemokine CTACK plays a key role in many inflammatory conditions and could be instrumental in the pathophysiology of tissue‐specific immunological diseases such as oral lichen planus ( OLP ). In this study, we investigated, by RT ‐ PCR , ELISA , chemotaxis assays, and fluorescence‐activated cell sorting ( FACS ), the production of CTACK in oral keratinocytes, its expression in tissues from normal and OLP patients, and its role in T‐cell recruitment . CTACK was produced by the oral epithelium, and it affects chemotaxis of memory CLA + cells to the oral epithelium. CTACK mRNA was expressed constitutively in primary oral epithelium and was increased during pro‐inflammatory IFN ‐γ treatment. We found a constitutive production of CTACK at a protein level in oral primary cells that increased after IFN ‐γ treatment. Moreover, we confirmed that CTACK attracts memory T cells and those T cells that express CLA above the level of basal migration.