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 periodontitis 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