A study on the role of humoral antibody against Bacteroides gingivalis.

牙龈拟杆菌与许多成人牙周炎病例有关。在我们的实验室已经报道了成人牙周炎患者对牙龈芽胞杆菌的体液免疫反应升高。在本研究中，我们研究了人血清中牙龈芽孢杆菌的杀菌活性与对该菌的IgG抗体水平的关系。在厌氧条件下，研究了牙龈芽孢杆菌菌株对补体介导的人血清杀菌活性的敏感性。血清中含有高浓度的IgG抗体，对微生物的杀菌活性增强。在不含特异性抗体的血清或完整细胞吸收的血清中未发现增强。不同菌种对混合血清杀灭的敏感性不同。牙龈芽孢杆菌细胞激活汇集的人血清补体不仅通过经典途径，而且通过另一种途径。结果表明，牙龈芽孢杆菌对抗菌活性的敏感性是典型的途径依赖性。我们报告了牙龈沟液含有相当数量的免疫球蛋白，含有牙龈B. IgG抗体和补体系统。这些发现可能支持牙龈缝隙中的特异性抗体和补体是宿主体内对微生物抗性的重要决定因素的论点。

Bacteroide gingivalis has been implicated in many cases of adult periodontitis. Elevation of humoral immune responses to B. gingivalis in subjects with adult periodontitis has been reported in our laboratory. In the present study, we investigated the relationship between bactericidal activity for B. gingivalis in human serum and IgG antibody levels to the organisms.Susceptibility of B. gingivalis strains to the complement mediated bactericidal activity of human serum was examined under anaerobic conditions. Serum containing high concentrations of IgG antibody to the microorganisms enhanced the bactericidal activity. No enhancement was found in serum which did not contain the specific antibody or in serum absorbed with intact cells. The sensitivity to the killing by pooled serum differed among B. gingivalis strains. Cells of B. gingivalis activated the pooled human serum complement not only through the classical pathway but also through an alternative pathway. It was found that the susceptibility of B. gingivalis to the bactericidal activity was classical pathway-dependent.We reported that gingival crevicular fluid contained both appreciable amounts of immunoglobulins containing IgG antibody to B. gingivalis and a complement system. These findings may support the argument that the specific antibody and complement in the gingival crevice are important determinants of host resistance to the micro-organism in vivo.