CD29 expression on CD4(+) gingival lymphocytes supports migration of activated memory T lymphocytes to diseased periodontal tissue

The cell surface phenotypes of CD4(+) cells extracted from inflammatory periodontal disease tissues were analyzed using two- and three-color immunofluorescence and flow cytometry. Cells extracted from both adult periodontal and localized juvenile periodontilis lesions showed a depressed CD4/CD8 ratio (1.0+/-0.1 adult periodontitis and 1.1+/-0.1 localized juvenile periodontitis) compared with cells recovered from normal/marginal gingivitis tissue (1.8+/-0.2) or with normal peripheral blood cells (2.1+/-0.1) or periodontal disease blood cells (2.1+/-0.1 and 1.7+/-0.1 for adult periodontitis and juvenile periodontitis, respectively). The monoclonal antibodies anti-2H4 and anti-4B4 were used to identify the CD45RA and CD29 antigens respectively on CD4(+) T cells from the periodontal disease lesions. In peripheral blood, CD29(+) cells accounted for 66-77% of the CD4(+) population, and CD45RA(+) cells accounted for 22-27% of the CD4(+) subset. No differences in expression were found between peripheral blood lymphocytes from normal subjects and from periodontal disease patients. Two-color analyses of lymphocytes from periodontal diseased tissues showed that 87-89% of the CD4(+) population were CD29(+) and that 70-79% of the CD4(+) cells were CD45RA(+). Normal tissues contained significantly fewer CD4(+)CD29(+) cells (56+/-4%) and CD4(+)CD45RA(+) cells (40+/-4%) on average, and few, if any double-labelled cells could be accounted for. These data implied that a significant percentage of the CD4(+) cells from the diseased tissues were both CD29(+) and CD45RA(+) and that these populations are found in quite different proportions in diseased periodontal tissue than in peripheral blood or nondiseased tissue. In further analyses using three-color cytometry the mean percentage of CD4(+)CD29(+)CD45RA(+) lymphocytes extracted from periodontal disease lesions was 43+/-9% of the CD4(+) population. These results suggest that CD4(+) T lymphocytes in periodontal disease not only demonstrate varying levels of maturity but also that the accumulation of CD4(+) T cells within the periodontal tissues may be a result of increased adhesion and transendothelial migration.