Degradation of immunoglobulins A2, A2, and G by suspected principal periodontal pathogens
Degradation of immunoglobulins A2, A2, and G by suspected principal periodontal pathogens
复制标题
疑似主要牙周病原体对免疫球蛋白 A2、A2 和 G 的降解
作者：
M. Kilian
最近人们的注意力集中在免疫球蛋白A1(IgA1)蛋白酶的产生上，它可能是与脑膜炎和淋病有关的细菌的毒力因子。这份报告表明，破坏性牙周病的可疑主要病原体包括能够降解IgA1、IgA2和Ig G的细菌。产黑拟杆菌亚种的代表菌株。黑色素产生菌和吞噬Capnocytopaga在铰链区裂解IgA1，但不裂解IgA2，产生完整的Fab和Fc片段。所有的Capnocytophaga菌株也都以同样的方式裂解IgG。大多数菌株为解糖拟杆菌和产黑素杆菌亚种。中间体可导致IgA1和多克隆抗体的完全降解。然而，一些菌株保留了IgA1的Fc部分。几株菌株也能完全分解IgA_2和S-IgA。从破坏性牙周病患者的整个龈下菌斑中检测到显著的IgA裂解酶活性。结果表明，Asaccharlyticus、B.Blackingenicus和Capnocytophaga spp.均能在龈下定植。可导致局部免疫防御机制瘫痪，从而促进潜在有毒物质、裂解酶和整个牙龈下微生物群释放的抗原的渗透和扩散。
Attention has recently been focused on immunoglobulin A1 (IgA1) protease production as a possible virulence factor of bacteria implicated in meningitis and gonorrhea. This report demonstrates that suspected principal etiological agents in destructive periodontal disease include bacteria capable of degrading IgA1, IgA2, and IgG. Representative strains of Bacteroides melaninogenicus subsp. melaninogenicus and Capnocytophaga cleaved IgA1 but not IgA2 in the hinge region to yield intact Fab and Fc fragments. All Capnocytophaga strains also cleaved IgG in the same way. The majority of strains of Bacteroides asaccharolyticus and B. melaninogenicus subsp. intermedius caused complete degradation of both IgA1 and polyclonal IgG. However, some strains left the Fc part of IgA1 intact. Several strains were also capable of completely decomposing IgA2 and S-IgA. Significant IgA-cleaving enzyme activity was detected in whole subgingival dental plaque collected from patients with destructive periodontal disease. The results indicate that colonization of the subgingival area by B. asaccharolyticus, B. melaninogenicus, and Capnocytophaga spp. can induce a local paralysis of the immune defence mechanisms, thereby facilitating the penetration and spread of potentially toxic substances, lytic enzymes, and antigens released by the entire subgingival microflora.