肺炎链球菌荚膜多糖O-乙酰化修饰的研究进展

Research progress in O-acetylation of capsular polysaccharide of Streptococcus pneumoniae

摘要:

肺炎链球菌表面覆盖着一层荚膜，由多糖组成，是肺炎链球菌关键的毒力因子和重要的抗原，也是细菌分型的依据。强毒血清型的荚膜多糖被制成糖疫苗在抗感染方面发挥了巨大作用。荚膜多糖结构复杂，经常被O-乙酰化修饰，这些多变的化学修饰扮演着重要的生物学角色。本文对肺炎链球菌荚膜多糖O-乙酰化修饰的研究进展进行了介绍，包括荚膜多糖的遗传基础、合成途径和血清学特征，荚膜多糖的O-乙酰化修饰的化学结构及其相应的O-乙酰基转移酶，O-乙酰化修饰的化学鉴定和生物学功能。同时，我们也总结了多糖O-乙酰化修饰在肺炎链球菌微进化中的作用和对糖疫苗的影响，并对今后的研究进行了展望。本综述旨在为研究荚膜多糖的O-乙酰化修饰的致病机制奠定基础，也为糖疫苗的设计提供指导。

Abstract:

Streptococcus pneumoniae is surrounded by capsular polysaccharide (CPS), which is a critical virulent factor of vbacteria, an antigen for host antibodies, but also a basis for serotyping. Some serotypes causes serious in vasive diseases to human, therefore, their CPSs are made into vaccines that have greatly reduced the infection from pneumococci. Many CPSs have complicated chemical structure and are usually decorated by O-acetyl groups. Capsular O-acetylation is easily changed and plays an important biological role. This review focuses on the research progress of pneumococcal O-acetylation. We introduce the genetic basis, biosynthesis and serological characterization of CPS. We make a summary for O-acetylated CPS structures and related O-acetyltransferases as well as the identification and biological function of O-acetylation. Meanwhile, we also discuss the effects of O-acetylation to pneumococcal microevolution and polysaccharide-vaccines. The prospects for future studies are finally proposed. This review is expected to lay the foundation for mechanism investigation of O-acetylation in pneumococcal invasion and provide a guide for designing polysaccharide-vaccines.