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

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.