EXPRESSION OF RECEPTOR BETA-CHAIN VARIABLE REGION BY T-CELLS IN HUMANPERIODONTAL-DISEASE

T cells play a major parr in the immune response in periodontal diseas es. In order to determine any selective T-cell receptor (TCR) beta-cha in variable region (V beta) usage in the infiltrates of healthy/ gingi vitis (H/G) and adult periodontitis (AP), cells were extracted from gi ngival biopsies, the CD4 and CD8 cells stained with antibodies to eigh t V beta regions, and two-colour flow cytometry used to analyse the da ta. The frequencies of CD4 and CD8 cells expressing each of the TCR-V beta families varied from 0 to 46% between individuals. A high percent age of CD4 and CD8 cells expressed the V beta 13 family in several AP biopsies, but, in a number of H/G tissues, a high percentage of T cell s expressed up to three families including the V beta 13 region, these varying from individual to individual. The mean results showed a sign ificantly greater percentage of V beta 5.2-3-positive CD4 cells (p = 0 .003) and V beta 5.1- and 5.2-3-positive CDS cells (p = 0.003 and 0.02 5, respectively) isolated From H/G than AP tissues. The percentage of V beta 3.1-positive CD4 cells extracted from H/G tissues was also high er but not quite significant at the 0.05 level (p = 0.051). Sections o f gingival tissue in biopsies from H/G and AP were stained in situ; th ere were no significant differences in the mean expression of V beta 3 .1-, 5.1- or 5.2-3-positive cells. A second aim was to determine the e ffect of Porphyromonas gingivalis on the TCR repertoire. There were no differences in the mean percentage of CD4 or CD8 cells expressing the right TCR-V beta regions between the two groups after stimulation in vitro with P. gingivalis outer-membrane antigens. There was, however, a trend towards a decrease in the percentage of positive CD4 and CDS T cells after culture with the antigen. This was significant for CD4 ce lls from H/G expressing the V beta 5.1 and 5.3 TCRs (p = 0.032 and p = 0.038, respectively). This trend was not evident for V beta 5.2-3-pos itive CD4 cells or V beta 5.1-positive CD8 cells isolated from both H/ G and AP nor for V beta 3.1-positive CD8 cells from AP. The results sh ow that there may be restricted V beta usage in gingival tissues, part icularly in H/G tissues. The V beta 5 and 3.1 families may be selected for in the gingival tissues and may also be involved in P. gingivalis activation. (C) 1997 Elsevier Science Ltd.