Abstract
Soluble sonic extracts (SE) from periodontopathic bacteria were studied for their effects on immunoresponse and adjuvanticity.
The preparations of SE from Capnocytophaga ochracea, C. Sputigena and Porphyromonas gingivalis were found to have strong immunomodulating activity against the antigen itself and also sheep erythrocytes (SRBC) in vivo, in experiments using C3H/HeN mice. The immune response was enhanced by the low concentration of tested SE. Strong immunosuppression was found at high concentrations of C. ochracea and C. sputigena but not of P. gingivalis and BSA. Furthermore, these suppressive effects were enhanced by 3-day-prior injection with SRBC even at low concentrations. The protein fraction of C. ochraceaand C. sputigena may play a significant role in this inimunomodulation, because suppressed anti-SRBC immune response was restored by either pronase treatment or heating. The results obtained from C3H/HeJ mice also indicated that immunosuppression induced by SE from C. ochracea and C. sputigena may be attributable to its protein since strong immunosuppression was induced. The present study strongly suggests that some periodontopathic bacteria have strong immunomodulatory activity, and long-term infection accompanied by proportional fluctuation in bacterial flora may induce aberrations in the immune system. These results also indicate that severe infection with oral or periodonodpathic bacteria may promote secondary or opportunistic infection in the gingival crevice locally, or even at sites distant from the oral cavity.
