Interactions between non-immune host cells and the immune system during periodontal disease: role of the gingival keratinocyte.

Periodontal disease and inflammatory dermatoses, such as psoriasis, are characterized by the accumulation of dense inflammatory infiltrates immediately beneath the epithelial cell layer of the gingiva and skin, respectively. Dermatologists are increasingly aware that the epidermal keratinocyte probably contributes to inflammatory disease progression by secreting a number of pro-inflammatory cytokines and expressing various adhesion molecules. In psoriatic lesions, it is now believed that epidermal keratinocytes may also act as antigen-presenting cells and participate directly in the superantigenic activation of T-cell clones, some of which may initiate, contribute to, or maintain the disease process. Although the role of the host response in periodontal disease has been extensively studied over the years, very little is known about the contribution of the gingival keratinocyte to the inflammatory response. The available published information is discussed in this review, and we suggest that, like its epidermal counterpart, the gingival keratinocyte may participate actively in the pathogenesis of periodontal disease.