Biased expression of T cell receptor V beta genes in periodontitis patients

The aim of the present study was to investigate the hypothesis that there is selective activation and expansion of a limited repertoire of T cell receptor (TCR)-bearing T cells in periodontitis tissue. We studied TCR V beta gene expression in gingival tissues of periodontitis lesions and compared these with peripheral blood mononuclear cells (PBMC) from the same patients using polymerase chain reaction (PCR) amplification with 22 V beta-specific sense primers in combination with a common antisense C beta-specific primer. After initial therapy, gingival tissue specimens were obtained from 14 periodontitis patients at the time of periodontal surgery, and PBMC were also obtained from the same patients by density gradient centrifugation. Total RNA was extracted and analysed by reverse transcription PCR. The PCR products were electrophoresed on a 2% agarose gel and stained with ethidium bromide. For each product, gingival tissue and the respective peripheral blood were compared. The TCR repertoire identified in the PBMC in general overlapped with that of the gingival tissue. However, V beta 6 appeared to be over-expressed in the gingival tissues compared with the PBMC, but V beta 16 appeared to be under-expressed in the gingival tissues. Although it is not known whether this is due to antigen-specific activation or superantigen activation, the data suggest that there may be as yet uncharacterized T cell subsets in periodontal disease tissue.