Expression of the cutaneous lymphocyte antigen and the αIELβ7 integrin by intraepithelial lymphocytes in healthy and diseased human gingiva

The presence of specific phenotypes of intraepithelial lymphocytes (IEL) was determined in healthy and diseased gingiva by immunohistochemistry. The cutaneous lymphocyte antigen (CLA) and the αIELβ7 integrin were detected with the HECA-452 and with the HML-1 monoclonal antibodies, respectively. Some 24–62% of CD3-positive intraepithelial lymphocytes expressed the CLA antigen in the junctional epithelium, while 49–54% expressed the αIELβ7 integrin. Similar results were obtained in the other gingival epithelia. The fraction of CLA-positive T cells and αIELβ7 integrin-positive T cells was significantly higher in the gingival epithelia than in the underlying connective tissue, indicating that the T-cell subsets defined by these surface adhesion molecules were selectively localized in the epithelial compartment. Comparison of the fractions of CLA-positive and αIELβ7 integrin-positive T cells across different disease groups did not show significant differences. The data indicate that intraepithelial lymphocytes expressing the CLA and the αIELβ7 phenotype are a quantitatively important component of gingival intraepithelial immunity. These adhesion molecules may play a part in the retention of specific T-cell subsets in gingival epithelia.