福氏志贺菌O-抗原磷酸乙醇胺修饰研究进展

Progress of O-antigen phosphoethanolamine modification of Shigella flexneri

福氏志贺菌是发展中国家引起痢疾的主要致病菌。福氏志贺菌O-抗原除噬菌体介导的糖基化和(或)乙酰化外,最近发现一种新的修饰方式磷酸乙醇胺修饰,其机制为由质粒携带的opt基因编码磷酸乙醇胺转移酶在O-抗原的鼠李糖II或(和)鼠李糖III上添加磷酸乙醇胺基团,从而形成血清型Xv、4av和Yv福氏志贺菌,并表达MASF IV-1抗原。人工转化携带opt基因的质粒到无MASF IV-1抗原表达的不同血清型福氏志贺菌中,转化菌株都能表达MASF IV-1抗原。在某些血清型福氏志贺菌中,O-抗原的磷酸乙醇胺修饰与糖基化、乙酰化修饰之间相互作用。现对福氏志贺菌的O-抗原磷酸乙醇胺修饰机制及其与糖基化、乙酰化修饰间的相互作用进行了综述。

Shigella flexneri is the major pathogen causing bacillary dysentery in the developing countries. Besides phage-encoded glucosylation and/or O-acetylation, O-antigen of S. flexneri modification with phosphoethanolamine（PEt N） has been identified lately. The plasmid-carried opt gene encodes the phospholethanolamine transferase adding a PEt N on O-antigen rhammose II and/or rhammose III. O-antigen PEt N modification of serotype X, 4a and Y strains convert the hosts into MASF IV-1 positive ＂variant＂ Xv, 4av and Yv serotypes respectively. The plasmidcarried opt gene is able to transform all S. flexneri serotypes to make them express MASF IV-1 epitope. Among various serotypes, the PEt N modification of O-antigen may interact with glucosylation and O-acetylation process. Now S. flexneri- O antigen ethanolamine phosphate modification mechanism and its interaction with glycosylation, acetylated modification were reviewed.