糖基化复杂壁磷壁酸的全合成及其免疫活性研究

Staphylococcus aureus， especially multidrug-resistant strains, have developed into a serious threat to human health. Bacterial vaccine is an effective strategy to combat these infections. However, all the current vaccine candidates are failed in clinical trials. Therefore, there is an urgent need to develop new immunity target and vaccine cadidate to prevent and treat this issue. Glycocalyx teichoic acids on the surface of s.aureus is a new potential immunity target. The current study aims to develop a new method to prepare complex glycocalyx teichoic acids by using soluble ionic liquild as supporters. To explore the detailed structre and immunological activity relationships, a small glycocalys teichoic acids antigen library will be constructed with varied lengths, glyco-densities, glycosylation patterns, with or without the reserved disaccharide linking unit. Conjugating these antigens to protein carrier TT generates s. aureus bacterial vaccine candidates, which will be used to immunize mice. The elicited immune responses in mice will be accessed by Enzyme linked immunosorbent assay (ELISA).The current studies will lead to a comprehensive understanding of glycocalyx teichoic acid sturcture and immunological activity relationship, which will provide a theory base for the future s. aureus bacterial vaccine development.

金黄色葡萄球菌，特别是具有多重抗药性的金葡菌已经对人类健康产生严重威胁。细菌疫苗是战胜细菌感染的有效手段，然后当前研制的针对金黄色葡萄球菌的细菌疫苗在临床试验中均未成功。因此，迫切需要发展新的免疫靶点，进而研制有效疫苗用来防治金黄色葡萄球菌感染。金黄色葡萄球菌表面的糖基化壁磷壁酸是一个新的、潜在的免疫靶点。本研究拟发展以可溶性离子液体为载体的新方法，以金黄色葡萄糖球菌细胞壁上的乙酰氨基葡萄糖化复杂壁磷壁酸为全合成目标;从壁磷壁酸的长度，糖基化构型，糖基化密度，以及高度保留二糖连接单元这四个方面入手，通过液相平行合成法构建结构确定，纯度均一的糖基化壁磷壁酸小型化合物库；与破伤风类毒素TT蛋白连接后制备成糖基化壁磷壁酸-蛋白候选疫苗；最后通过酶联免疫吸附测定法全面评价候选疫苗的免疫活性。为从分子水平上阐明糖基化壁磷壁酸结构与免疫活性之间的关系，进而发展金黄色葡萄球菌的细菌疫苗研究提供理论基。

具有多重耐药性的金黄色葡萄球菌是人类健康的严重威胁。本项目以金黄色葡萄球菌表面的糖基化壁磷壁酸为免疫靶点，发展多糖蛋白结合疫苗用于该类细菌的防治。本项目建立了以离子液体为可溶性载体的液相平行合成新方法，合成了结构确定，纯度均一的壁磷壁酸库，该法可以合成1至9聚核糖醇磷酸酯类化合物，反应的总体效率和产率分别是以61.5小时，27步，总产率13%获得9聚核糖醇磷酸酯；在此基础上，完成了以离子液体为载体合成带有连接臂的糖基化壁磷壁酸方法学研究。该法为进一步获得结构复杂的糖基化壁磷壁酸抗原，探索其结构与免疫活性之间的关系奠定了基础；项目还完成了肠球菌表面糖基化壁磷壁酸化合物-6-(GalNAc-ɑ(1–3)-GalNAc-β(1–2)-GroP)的全合成及其免疫活性研究，小鼠免疫实验及抗体滴度测定表明了该糖蛋白缀合物可以有效地激起免疫反应，并产生特异性的抗体。该半合成糖-蛋白缀合物可以被用于开发屎肠球菌E. feacium的疫苗。