Expression of T-cell receptor V beta 2, 6 and 8 gene families in chronic adult periodontal disease

Substantial evidence exists to suggest a role for T-cells in periodontal disease. As yet, however, the T-cell receptors remain to be characterised at the molecular level. The expression and the nucleotide sequence of genes from the T-cell receptor beta variable (TCRBV) gene families 2, 6 and 8 were analyzed in periodontal tissue from 24 patients with chronic adult periodontal disease (CAPD) and peripheral blood lymphocytes (PBL) of 16 of these patients. A restriction in the expression of these TCRBV gene families was detected in periodontal tissue from 14/24 patients with CAPD, and the pattern of gene expression was often different between individual patients; however there was no restriction in TCRBV gene expression in matched PBL samples from 8 of these 14 patients. Quantitative RT-PCR analysis of samples from 5 CAPD patients who expressed all 3 TCRBV gene families in their periodontal tissues did not reveal any significant differences in the levels of gene expression in periodontal tissue and PBL. In contrast to the findings with some CAPD patients, genes from all 3 TCRBV families were always expressed in periodontal tissue and PBL from disease-free control subjects. PCR products from both the PBL and periodontal tissue of CAPD patients were cloned and sequenced; analysis of the nucleotide sequence revealed diversity with respect to the expression of TCRB joining (TCRBJ) and TCRB diversity (TCRBD) genes and the sequence of the junctional region in all samples analysed. In conclusion, in CAPD, the pattern of TCRBV gene expression in periodontal tissue is often but not always different from that in PBL and healthy periodontal tissue, which may indicate, in some cases, a local influence on particular T-cell subsets which is relevant to the pathogenesis of periodontal disease. However, the expressed TCRB genes are heterogeneous at the nucleotide level, emphasising the underlying complexity at the molecular level in the local T-cell response in CAPD.