|Budget Amount *help
¥1,900,000 (Direct Cost : ¥1,900,000)
Fiscal Year 1992 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1991 : ¥1,100,000 (Direct Cost : ¥1,100,000)
Recent studies showed that CD45RO+ memory T-cells play important roles in the immunoglobulin production of B-cells by producing various B-cell activating cytokines and cell-cell contact due to enhanced expression of adhesion molecules. This study was designed to investigate frequency and distribution of memory T-cells and activated B-cells in cryostat sections of adult periodontitis and gingivitis lesions by immunohistochemical double staining. We used the same technique to examine T-B interactions in situ by staining: T-cells producing IL-4 which enhances CD23 expression on B-cells, LFA-1 on T-cells, and ICAM-1 on B-cells. Nineteen gingival biopsies were obtained at the time of periodontal surgery following the completion of initial preparation and 5 gingivitis biopsies were obtained from premolar sites requiring extraction for the orthodontic treatment and third molar sites. Serial 6 um-thick cryostat sections were obtained from the central part of each biopsy. Double staining by avi
din-biotin- immunoperoxidase and avidin-biotin-alkaline phosphatase or alkaline phosphatase anti-alkaline phosphatase techniques were used to identify CD4+CD45RO+ memory T-cells, IL-4+CD45RO+ cells, LFA-1+CD45RO+ cells, ICAM-1+CD19+ B-cells and CD23+ or CD25+,CD19+ activated B-cells. The mean percentage of CD45RO+ memory cells among CD4+ cells was consistently high (65.9% in the crevicular one-third, 61.2% in the middle one-third, 62.5% in the oral one-third), whereas the mean percentage of CD45RA+ naive cells among CD4+ cells was low (17.1% in the crevicular one-third, 14.8% in the middle one-third and 12.4% in the oral one-third). In gingivitis biopsies, T-cells were the major cell type and most of CD4+ cells were CD45RO+. IL-4 producing cells were observed as clusters and/or single cells with various staining intensity in 14 out of 19 periodontal tissues, however, they were much lower in number compared with CD45RO+ cells. On the other hand, the percentage of CD23+ and CD25+, CD19+ B-cells displayed pronounced individual variations (0-100% for CD23, 0-36.2% for CD25) even though the clinical status was similar. Some CD19+ B-cells with enhanced expression of ICAM-1 were identified. The above findings suggest that: 1)early activation events of T-cells and B-cells may take place possibly in the regional lymphnodes before infiltrating into the periodontitis lesion; 2)B-cells infiltrating into the periodontitis lesion displayed features attributable to several different stages of differentiation pathway into plasma cells.