Aspects of the Cellular Immune Response in Periodontal Disease

Koulouri, Ourania (1998) Aspects of the Cellular Immune Response in Periodontal Disease. Master in Medical Science thesis, University of Glasgow.

Abstract

Studies on the kinetics of inflammatory/ immune cells have been undertaken in our laboratory and these investigations were confined to the inflamed gingival tissue obtained from adult periodontitis patients. Furthermore, it has been reported that studies of the superficial gingiva are probably not sufficient to give a clear picture of the inflammatory and immune processes of severe periodontitis (Moskow & Poison, 1991). In an attempt to acquire a better knowledge of the dynamics and complex interactions among the immune cells in periodontitis sites, deeper granulation tissue was examined and compared with superficial gingival tissue. The highly vascular and heavily infiltrated granulation tissue was obtained from adult periodontitis and early onset periodontitis patients during surgery and the biopsies were taken from the most apical part of the periodontal pocket. A thorough investigation of the periodontal granulation tissue has not been performed so far. Therefore, the detection of this type of tissue may lead to interesting findings. Two techniques were employed throughout the studies comprising this thesis; immunohistochemistry and in situ hybridisation were used to assess immune cells' kinetics and synthetic activity and to examine possible differences within the two types of tissue and the two forms of periodontal disease. Phenotypic analysis of cell surface markers and qualitative and quantitative assessment of the cellular infiltrate (macrophages, B cells, T cells, T cell subsets i.e. memory, helper and suppressor) were carried out using immunohistochemistry. Combination with in situ hybridisation offered the opportunity to further elucidate synthetic capacity, proliferation and apoptosis in these cells by detecting their messenger RNA (mRNA) content in vivo. In order to examine the local antibody production and to determine their relative proportions in granulation tissue compared to gingiva, complementary oligonucleotide probes against specific mRNA sequences of IgG, IgA, IgM and IgE subclasses were utilised. Secretory IgA and IgM were evaluated in an attempt to assess their probable origin and destination and to compare their relative numbers within the two tissues. Furthermore, comparison was made between AP and EOP granulation tissue specimens for all the variables mentioned above in order to give an insight in the histopathology of the two forms of periodontal disease. When cellular synthetic activity was examined with the oligo d(T) and 28S rRNA probes, it was found that the staining intensity of epithelial and plasma cells was strong. Slight to moderate staining was observed in fibroblasts, macrophages, giant cells, endothelial cells and lymphocytes with no difference in the numbers of any of the cell types among the tissue groups. Further localisation of the mononuclear cells, according to their CD antigen markers, revealed a mixed reaction, ranging from a few strongly stained through weakly positive to negative. It was concluded that plasma cells are synthetically active in both tissue groups, but lymphocytes do not exhibit a major synthetic capacity within the actual tissue sites. Histone probe and anti-Ki-67 monoclonal antibody were used for the detection of proliferating cells and it was revealed that epithelium, mononuclear cells and fibroblasts stained positive, but the overall numbers of dividing cells (excluding epithelium) in the gingival and granulation connective tissues were small. It was also noted that CD positive cells were stained negative for the proliferation markers. An interesting finding was that the numbers of proliferating cells were significantly higher in the granulation compared to gingival tissue biopsies, and this could be accounted for by the numbers of fibroblasts. Fibroblasts could proliferate in an attempt to rearrange the borders of the actual inflamed area. Collectively, it could be hypothesised that leukocytes do not actively proliferate or synthesise proteines in the periodontally affected tissues. The possibility exists that already differentiated and committed B and T cells arrive in the inflamed tissues and that this differentiation occurs in more distant sites i.e. lymph nodes. The recruitment of cell clones which are specific for some plaque- derived antigens, occurs by migration rather that by proliferation. Apoptosis was not found to be a major feature in the inflamed gingival and granulation tissues. Some epithelial cells, fibroblasts and possibly PMNs were stained positive, but neither lymphocytes normacrophages exhibited any apoptotic function. This could lead to the result that lymphocytes and macrophages are long-lived cells within the periodontal gingival and granulation tissues and that they exert their effects for a long period of time. In conclusion, it seems that the actual turnover rate of leukocytes is very slow in the tissues studied. Mononuclear cells were further differentiated and their occurrences were studied. (Abstract shortened by ProQuest.).

• Item Type: Thesis (Master in Medical Science)
• Qualification Level: Masters
• Additional Information: Adviser: D F Kinane
• Keywords: Dentistry
• Date of Award: 1998
• Depositing User: Enlighten Team
• Unique ID: glathesis:1998-75942
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 19 Nov 2019 17:14
• Last Modified: 19 Nov 2019 17:14
• URI: https://theses.gla.ac.uk/id/eprint/75942