Objective

Secreted IgA (SIgA) plays a central role in preventing bacterial and viral infections on mucosal surfaces by neutralizing toxins and viruses and inhibiting bacterial attachment to epithelial cells. However, the role of salivary SIgA antibodies (Abs) in regulating oral flora is still unknown. This study aimed to evaluate the association among oral bacteria, their metabolites and periodontitis in IgA-deficient (IgA KO) and wild-type (WT) control mice.

Methods

Microcomputed tomography (micro-CT) analysis was used to assess alveolar bone resorption as a development of periodontitis. The bacterial profiles of saliva were determined using the next-generation sequencing assays. Furthermore, the metabolites in saliva were measured and compared using CE-TOFMS.

Results

Salivary microbiota of IgA KO mice revealed a remarkably decreased frequency of Streptococcus, and increased percentages of Aggregatibacer, Actinobacillus, and Prevotella at the genus level when compared with those of WT. Compared to WT control mice of the same age, the level of alveolar bone loss was significantly increased in IgA KO mice, and infiltration of osteoclasts was found on the surface of the alveolar bone. The metabolome profile indicated that the metabolites of IgA KO mice had greater variability in carbon metabolic, urea cycle, and lipid pathways than WT mice.

Conclusion

These results suggest that salivary SIgA plays an important role in regulating and maintaining normal oral microflora to prevent the development of periodontal disease.

中文翻译：

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唾液 SIgA 抗体受损会引起口腔生态失调，进而导致牙槽骨流失

 客观的

分泌型 IgA (SIgA) 通过中和毒素和病毒并抑制细菌附着于上皮细胞，在预防粘膜表面细菌和病毒感染方面发挥着核心作用。然而，唾液SIgA抗体（Abs）在调节口腔菌群中的作用仍不清楚。本研究旨在评估 IgA 缺陷 (IgA KO) 和野生型 (WT) 对照小鼠口腔细菌及其代谢物与牙周炎之间的关联。

 方法

显微计算机断层扫描 (micro-CT) 分析用于评估牙周炎发展过程中的牙槽骨吸收。使用下一代测序分析确定唾液的细菌谱。此外，使用 CE-TOFMS 测量和比较唾液中的代谢物。

 结果

与 WT 小鼠相比，IgA KO 小鼠的唾液微生物群显示，链球菌属的频率显着降低，聚集杆菌属、放线杆菌属和普雷沃氏菌属水平的百分比增加。与同龄WT对照小鼠相比，IgA KO小鼠牙槽骨丢失水平显着增加，且牙槽骨表面可见破骨细胞浸润。代谢组谱表明，IgA KO 小鼠的代谢物在碳代谢、尿素循环和脂质途径方面比 WT 小鼠具有更大的变异性。

 结论

这些结果表明唾液SIgA在调节和维持正常口腔微生物群以预防牙周病的发展中发挥着重要作用。