Oligoclonal accumulations of T-cell clones in gingivitis and periodontitis lesions.
Gingivitis and periodontitis have distinct clinical and immunopathological characteristics. We have previously demonstrated that T cells infiltrating periodontitis lesions recognize a restricted repertoire of antigens or antigenic epitopes. However, the clonality of T cells in the gingivitis lesion is not known. Therefore, we carried out a clonal analysis of T cells infiltrating gingivitis lesions using combined reverse transcription-polymerase chain reaction and single-strand conformation polymorphism (SSCP) analysis. As with periodontitis lesions, SSCP analysis demonstrated the emergence of a number of distinct bands suggesting clonal accumulation in the gingivitis lesion. Although the mean number of distinct bands in gingival tissue was significantly higher than that in peripheral blood mononuclear cells, numerical analysis clearly demonstrated that there was no difference in the total number of bands in gingival tissue specimens between the different disease types. Although there were slight variations in the number of distinct bands in each Vbeta family, there was no significant difference between gingivitis lesions and periodontitis lesions. These results demonstrate that antigen-specific T-cell responses also take place in gingivitis lesions. It remains to be determined, however, what role these antigen-specific T cells play and what antigens the T cells recognize in the pathogenesis of periodontal disease.