Anti-Idiotypic Antibody to anti-Porphyromonas gingivalis Antibody in Sera from Patients with Adult Periodontitis

• Published in: Nihon Shishubyo Gakkai Kaishi (Journal of the Japanese Society of Periodontology) Vol. 35; no. 1; pp. 63 - 83
• Main Author: KAWAI, Toshihisa
• Format: Journal Article
• Language: Japanese
• Published: JAPANESE SOCIETY OF PERIODONTOLOGY 1993
• Subjects: Humoral immunity; Idiotype network; Periodontal diseases; Porphyromonas gingivalis; Serum antibody
• ISSN: 0385-0110; 1880-408X
• DOI: 10.2329/perio.35.63

Idiotype (Id) -anti-Id interaction has been shown to be an important immunoregulatory mechanism. It is, therefore, plausible that the antibody response to Porphyromonas gingivalis, which is commonly found in periodontitis patients, is also controlled by the Id network. However, to our knowledge, there have been no reports concerning the Id-anti-Id interaction in this disease. The purpose of this study was to demonstrate anti-Id antibody (Ab 2) directed against the anti-P. gingivalis antibody (Ab 1) in human sera. Several monoclonal antibodies (MoAb) were prepared in BALB/c mice immunized with crude P. gingivalis antigen. One of the MoAb, termed PF 18, recognized an epitope of the saccharide moiety on the cell surface of the organism, and competed with Abl in sera derived from all 10 patients examined. The Fab fragment from PF 18 was utilized as a substitute for the idiotype of the human Ab 1 in the following experiments. Anti-PF 18 Id (Ab 2) activity was detected by ELISA in 9/10 patients only after absorption of sera with immobilized P. gingivalis. However, this activity was not demonstrated in control sera from healthy subjects. The results suggest that the Ab 1 and the Ab 2 associated with each other and formed soluble immune complexes in the sera of patients. Affinity purified antigen preparation by PF 18-MoAb from a sonic extract of P. gingivalis was capable of inhibiting the Ab 2 anti-Id activity in human sera. Monoclonal anti-PF 18-Id antibody (APF 1) was established in a syngenic BALB/c mouse. Both APF 1 and PF 18 itself blocked the human Ab 2 activity, but not the other MoAbs directed against P. gingivalis. These results suggest that the human Ab 2 reacted with the paratope of PF 18. The PF 18-Id bearing Ab 1 was detected by binding of APF 1 in the 9 patients exhibiting the Ab 2 activity, and 2/10 control subjects. Production of anti-PF 18-Id Ab 2 was confirmed in mice injected with P. gingivalis. This Ab 2 was also detectable in sera after absorption with immobilized antigen as well as human Ab 2. The Ab 2 activity was rather quickly elevated, within 2 days after the booster injection, as compared with the anti-P. gingivalis Ab 1 activity, which reached a maximum at 16 days after the booster. This cyclic response may reflect a promoting role of the anti-Id antibody in the anti-P. gingivalis response. Taken together, the results of this study suggest that the idiotype network regulatory mechanism may play an important role in the immune responses of human adult periodontitis. The presence of and -Id antibody seems to be closely related to the existence of the disease.