Institute for Pharmaceutical Biology and Biotechnology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany.
CIC bioGUNE, Bizkaia Technology Park, Ed. 801A, Derio 48160, Spain.
Biochem J. 2019 Jul 18;476(14):1995-2016. doi: 10.1042/BCJ20190324.
Bacterial capsules have evolved to be at the forefront of the cell envelope, making them an essential element of bacterial biology. Efforts to understand the (Mtb) capsule began more than 60 years ago, but the relatively recent development of mycobacterial genetics combined with improved chemical and immunological tools have revealed a more refined view of capsule molecular composition. A glycogen-like α-glucan is the major constituent of the capsule, with lower amounts of arabinomannan and mannan, proteins and lipids. The major Mtb capsular components mediate interactions with phagocytes that favor bacterial survival. Vaccination approaches targeting the mycobacterial capsule have proven successful in controlling bacterial replication. Although the Mtb capsule is composed of polysaccharides of relatively low complexity, the concept of antigenic variability associated with this structure has been suggested by some studies. Understanding how Mtb shapes its envelope during its life cycle is key to developing anti-infective strategies targeting this structure at the host-pathogen interface.
细菌荚膜已经进化到处于细胞包膜的前沿，使它们成为细菌生物学的重要组成部分。人们对结核分枝杆菌（Mtb）荚膜的研究已经有 60 多年了，但相对较近的分枝杆菌遗传学的发展，加上改进的化学和免疫学工具，揭示了对荚膜分子组成的更精细的看法。一种类似于糖原的α-葡聚糖是荚膜的主要成分，阿拉伯甘露聚糖和甘露聚糖、蛋白质和脂质的含量较低。Mtb 主要荚膜成分介导与吞噬细胞的相互作用，有利于细菌的存活。针对分枝杆菌荚膜的疫苗接种方法已被证明在控制细菌复制方面是成功的。尽管 Mtb 荚膜由相对简单的多糖组成，但一些研究表明，与该结构相关的抗原变异性的概念。了解 Mtb 在其生命周期中如何塑造其包膜，是针对宿主-病原体界面上的这种结构开发抗感染策略的关键。
