B‐Lymphocyte Blastogenesis in Response to Periodontitis‐Associated Bacteria: Kinetics and Proportion of Total Response

Abstract

A role for activated b‐lymphocytes in mediating the initiation and/or progression of periodontal diseases has been proposed in previous work. The present study was conducted to: (1) assess the proportion of total lymphocyte blastogenic response to selected oral bacteria which is composed of T‐cell and B‐cell activation, respectively, and (2) to determine whether different kinetic patterns exist for the T‐cell vs. the B‐cell responses to these bacteria. Using lymphocyte rosetting and culturing techniques, rosette‐positive and rosette‐negative lymphocyte preparations were examined for blastogenic responsiveness following stimulation with a variety of both Gram‐positive and Gram‐negative periodontitis‐associated bacteria. Results of these studies indicated that both peripheral blood lymphocytes (PBL) from healthy adults and cord blood lymphocytes (CBL) from placental afterbirths responded to these bacteria with similar kinetic patterns. The net PBL blastogenic response appeared to consist of an early B‐cell response, which peaked at Days 2 or 3 of culture, followed by a later T‐cell response, which peaked at Days 5 to 6 of culture. The B‐cell response appeared to be T‐cell‐dependent in that B‐cells cultured alone showed minimal thymidine uptake over the entire 6‐day period, but the addition of irradiated T‐cells to these B‐cell cultures resulted in a greatly enhanced B‐cell response.

Destructive Periodontitis Lesions are Determined by the Nature of the Lymphocytic Response

“…Sonic extracts of periodontopathic bacteria were first shown to induce polyclonal B-cell activation of peripheral blood lymphocytes, as assessed by the plaque-forming cell response to sheep red blood cells (Bick et al ., 1981;Donaldson et al ., 1982) and by the production of antibodies to several different organisms as well as specific antibody to the stimulating organism (Mangan et al ., 1983;Carpenter et al ., 1984). Several studies have shown that this polyclonal B-cell response to oral organisms is dependent on the presence of T-cells (Donaldson et al ., 1984;Okada et al ., 1987;Ito et al ., 1988). While most of these studies examined peripheral blood responses, an in situstudy recently reported that local proliferation of B-cells does not occur in periodontitis tissues, although plasma cells showed strong synthetic activity (Takahashi et al ., 1996).…”

Cytotoxic and immunostimulatory effects of Bacteroides cell products

“…While chronic adult periodontal disease is viewed primarily as a plasma cell lesion, the initiation and periodic nature of this disease suggests the importance of T-cell interactions (17,18). Lymphocyte-mediated cytotoxicity may also play a role in periodontal and periapical disease through antibody dependent cellular cytotoxicity or natural killer (NK) cell activity as has been suggested by in vitro studies (19).…”