Costimulatory molecules in human periodontal disease tissues

An immunoperoxidase technique was used to examine CD28, CD152. CD80 and CD86 positive cells in gingival biopsies from 21 healthy/gingivitis and 26 periodontitis subjects. The samples were placed into 3 groups (small, intermediate. large) according to the size of the infiltrate. The percent CD28 + T cells in the connective tissue infiltrates was highly variable with no differences between the healthy/gingivitis and periodontitis groups. While there was an increase in positive sails in intermediate infiltrates from both healthy/gingivitis (28.5%) and periodontitis (21.4%) patients compared with small infiltrates (8.6% and 11.8% respectively), this was not significant, although the percent CD28 + T cells did increase significantly in tissues with increased proportions of B cells relative to T cells (p =0.047). A mean of less than 5% infiltrating T cells were CD152 + which was significantly lower than the mean percent CD28 + T cells in intermediate healthy/gingivitis lesions (p = 0.021). The mean percent CD80 + and CD86 + B cells and macrophages was 1-7% and 8-16%, respectively, the difference bring significant in intermediate healthy/gingivitis tissues (p=0.012). Analysis of these cells in relation to increasing numbers of B cells in proportion to T cells and also to macrophages, suggested that CD80 was expressed predominantly by macrophages while CD86 was expressed by both macrophages and B cells. Few endothelial cells expressed CD80 or CD86, Keratinocytes displayed cytoplasmic staining of CD80 rather than CD86 although the numbers of positive specimens in the healthy/gingivitis and periodontitis groups reduced with increasing inflammation. In conclusion, percentages of CD28, CD152, CD80 and CD86 did not reflect differences: in clinical status. However, the percent CD28 + T cells increased with increasing size of infiltrate and with increasing proportions of B cells suggesting increased T/B cell interactions with increasing inflammation. The percent CD152 + cells remained low indicating that CD152 may not be involved in negative regulation of T cells in periodontal disease. CD80 and CD86 have been reported to promote Th1 and Th2 responses, respectively, and the higher percent CD86 + cells suggests a predominance of Th2 responses in both healthy/gingivitis and periodontitis tissues. Nevertheless, other factors including cytokines themselves and chemokines which modulate T cell cytokine profiles must be monitored to determine the nature of Th1/Th2 responses in periodontal disease.