In an attempt to characterize TCR V gene usage in human periodontally diseased tissue, V alpha 2, V beta 5.2-3, V beta 5.3, V beta 5.1, V beta 6.7, V beta 6.7, V beta 8 and V beta 12.1 expressions were examined. Serial cryostat sections obtained from 20 periodontitis and 9 gingivitis biopsies were then reacted with monoclonal antibodies directed to each repertoire. The technique was combined with a sensitive alkaline phosphatase-anti-alkaline phosphatase method. Peripheral blood was obtained from 10 periodontitis and 2 gingivitis patients. TCR repertoire was also quantified by flow cytofluorography with FITC-conjugated antibodies. Cells displaying binding of each antibody were counted. The proportions to CD3-positive cells were then calculated. The pattern of each TCR V gene product expression in inflamed gingiva exhibited individual variation, nevertheless, a consistent pattern emerged. The V beta 5 subfamily and V beta 6.7 were frequently used repertoires in gingiva, whereas the V alpha 2 and V beta 8 subfamily were underexpressed in most cases. Furthermore, the TCR V gene product expression in gingival tissue was biased compared with autologous peripheral blood. Three of 10 periodontitis subjects showed 1 or 2 strikingly overrepresented repertoire comparatively with autologous blood. In these 3 subjects V beta 6.7 was overexpressed in two cases and 5.2-3, V beta 8 and V beta 12.1 were overexpressed in one case. These results suggest that gingival T-cells are not randomly mobilized from peripheral blood and that local events influence the TCR repertoire at the level of T-cell recruitment or T-cell expansion.