Autologous Mixed Lymphocyte Reaction of Peripheral Blood Lymphocytes in Adult Periodontitis

• Published in: Nihon Shishubyo Gakkai Kaishi (Journal of the Japanese Society of Periodontology) Vol. 32; no. 2; pp. 355 - 369
• Main Author: FUJIMOTO, Naoki
• Format: Journal Article
• Language: Japanese
• Published: JAPANESE SOCIETY OF PERIODONTOLOGY 1990
• Subjects: Adult periodontitis; Autologous mixed lymphocyte reaction; CD 45 R; IL-2production; T-cell subset
• ISSN: 0385-0110; 1880-408X
• DOI: 10.2329/perio.32.355

Immunological mechanisms have been implicated in the pathogenesis and/or progression of human periodontal diseases. Therefore, recent studies have focused on the immunoregulatory mechanisms in periodontal diseases. T-cells have been recognized to play a central role in the immunoregulatory network at both local and systemic levels. The autologous mixed lymphocyte reaction (AMLR), which is thought is thought to be a T-cell reaction involving recognition of HLA-DR antigen expressed on non-T-cells, has been suggested as a possible indicator of immunoregulation in autoimmune diseases such as systemic lupus erythematosus. In the present study, AMLR in patients with adult periodontitis were evaluated. In addition phenotypic and functional characteristics of peripheral blood Tcells from patients showing low response in AMLR was investigated. The effect of periodontal therapy on AMLR was also examined. T-cell and non-T-cell fractions were separated from peripheral blood of 80 patients with adult periodontitis using the method of E-rosette formation. The T-cell fraction was incubated with Mitomycin-C-pretreated non-T-cell fraction for 7 days at 37.. in a humidified 5% CO2 atmosphere. The AMLR was expressed as the incorporation of 3H-thymidine for the previous 20 hours of culture (Δdpm). Phenotypic analysis of both T-cells and non-T-cells was performed using flow cytometry by means of direct immunofluorescence technique using monoclonal antibodies against cell surface antigens including CD 4, CD 8, CD 36, HLA-DR, and CD 45 R. The functional analysis of T-cells was evaluated by IL-2 production in AMLR by means of bioassay using an IL-2-dependent T-cell line, CTLL-2. AMLR responses in 80 periodontitis patients ranged from 51 to 59485 dpm (17607± 1428 dpm ; mean±SEM), while those of controls ranged from 13311 to 41636 dpm (24980±1332 dpm). Thirty-one of 80 adult periodontitis patients (39%) showed significantly lower responses in AMLR (<mean-2 SD of control group) than healthy subjects. No significant differences were observed in clinical parameters including probing depth, gingival index, alveolar bone loss and percentage of affected teeth between patients showing depressed AMLR (low-AMLR patients) and normal AMLR (normal-AMLR patients). Phenotypic analysis of non-T-cell fractions revealed no significant differences in the percentages of monocytes and HLA-DR expressed B-cell. In contrast, the phenotypic analysis of T-cell fractions revealed that the percentage of CD 45R-positive cells in CD 4-positive cells (CD 4+CD 45R+cells) was significantly lower in low-AMLR patients than in normal-AMLR patients and healthy subjects. In addition, no signi-gcant differences were found in the percentages of CD 4-positive and CD 8-positive cells and the CD 4/CD 8 ratio between these three groups. Interleukin-2 production in AMLR was significantly depressed only in low-AMLR patients. Depressed AMLR responses and low proportions of CD 4+CD 45R+ cells were recovered during conventional periodontal therapy. These results indicate existence of a patient group showing low AMLR responses in clinically-diagnosed “adult periodontitis ” patients . It was also suggested that there could be phenotypic and functional disorders in peripheral blood T-cells in these patients, which might be closely related to the depression of AMLR. In addition, depressed AMLR responses in these low-AMLR patients might reflect changes in regulatory T-cell function induced by the state of periodontal disease.