Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA.
Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA
Microbiol Mol Biol Rev. 2020 Feb 12;84(1). doi: 10.1128/MMBR.00065-19. Print 2020 May 20.
is a tier 1 select agent responsible for tularemia in humans and a wide variety of animal species. Extensive research into understanding the virulence factors of the bacterium has been ongoing to develop an efficacious vaccine. At least two such virulence factors are described as capsules of : the O-antigen capsule and the capsule-like complex (CLC). These two separate entities aid in avoiding host immune defenses but have not been clearly differentiated. These components are distinct and differ in composition and genetic basis. The O-antigen capsule consists of a polysaccharide nearly identical to the lipopolysaccharide (LPS) O antigen, whereas the CLC is a heterogeneous complex of glycoproteins, proteins, and possibly outer membrane vesicles and tubes (OMV/Ts). In this review, the current understanding of these two capsules is summarized, and the historical references to "capsules" of are clarified. A significant amount of research has been invested into the composition of each capsule and the genes involved in synthesis of the polysaccharide portion of each capsule. Areas of future research include further exploration into the molecular regulation and pathways responsible for expression of each capsule and further elucidating the role that each capsule plays in virulence.
是一种一级选择剂，可导致人类和多种动物的土拉菌病。为了开发有效的疫苗，人们一直在进行广泛的研究，以了解该细菌的毒力因子。至少有两种这样的毒力因子被描述为：O 抗原荚膜和类似荚膜的复合物（CLC）。这两个独立的实体有助于逃避宿主的免疫防御，但尚未明确区分。这些成分是不同的，在组成和遗传基础上有所不同。O 抗原荚膜由一种多糖组成，几乎与脂多糖（LPS）O 抗原相同，而 CLC 是糖蛋白、蛋白质以及可能的外膜囊泡和管（OMV/Ts）的异质复合物。在这篇综述中，总结了对这两种荚膜的现有认识，并澄清了关于 的“荚膜”的历史参考文献。已经投入了大量研究来研究每个荚膜的组成以及参与每个荚膜多糖部分合成的基因。未来的研究领域包括进一步探索每个荚膜表达的分子调控和途径，并进一步阐明每个荚膜在毒力中的作用。
