中国脑膜炎奈瑟菌蛋白疫苗抗原基因多态性分析

发布时间：2018-04-12 05:56

本文选题：脑膜炎奈瑟菌 + 奈瑟菌黏附素A(NadA)　；参考：《中国疾病预防控制中心》2012年硕士论文

【摘要】：脑膜炎奈瑟菌(Neisseria meningitidis, Nm)为革兰阴性双球菌,主要引起流行性脑脊髓膜炎(简称流脑)和败血症。根据菌体表面荚膜多糖的差异,Nm分为12个血清群,其中A、B、C、Y、W135和X群是引起全球脑膜炎球菌病的主要血清群,许多菌株血清群不可分,称为不可分群(Nongroupable,NG)菌株。流脑是疫苗可以预防的疾病,荚膜多糖是流脑疫苗的主要抗原成分,目前已有A,C,W135和Y群单价/多价的多糖疫苗和多糖-蛋白结合疫苗,疫苗应用降低了流脑的发病率和死亡率。由于B群脑膜炎奈瑟菌(Serogroup B Meningococcus, MenB)的荚膜多糖免疫原性较弱,并且荚膜多糖的唾液酸结构与人类神经细胞黏附因子具有同源性,免疫接种有可能引起自身免疫,因此,普遍认为荚膜多糖不适用于MenB疫苗的研发。近年来国际上开展了MenB蛋白疫苗研究工作,通过反向疫苗学技术研制出MenB蛋白疫苗5CVMB(5Component Vaccine against Meningococcus B)。5CVMB由五种脑膜炎奈瑟菌抗原成分组成：奈瑟菌黏附素A(NadA)、H因子结合蛋白(FHbp)、GNA2091、奈瑟菌肝素结合抗原(NhbA)和GNA1030。 MenB蛋白疫苗5CVMB中5种抗原成分不仅存在于MenB,在非B群Nm菌株中同样是存在的。MenB蛋白疫苗5CVMB不仅可预防MenB,对其他血清群的Nm也同样具有预防效果,可作为通用疫苗针对不同血清群的Nm进行有效预防。本研究对我国不同血清群Nm菌株蛋白疫苗抗原基因的分布及氨基酸序列多态性进行研究,以期掌握MenB蛋白疫苗与我国Nm菌株之间的相互覆盖率。研究结果显示,我国不同血清群Nm菌株中均存在fHbp、nhba、gna1030和gna2091四种基因。210株Nm菌株中仅48株含有nadA基因(48/206,23.3%),其中,44株Nm菌株属于ST-5complex,4株Nm菌株属于ST-11complex。通过氨基酸序列分析,48株NadA阳性菌株中,NadA变异型3(NadA V3)47株(97.92%)。对110株Nm菌株fHbp基因进行测序,49株(44.55%)为FHbp V1,52株(47.27%)为FHbp V2,9株(8.18%)为FHbp V3o 5CVMB中主要抗原成分FHbp和NadA亚型在我国不同血清群Nm菌株中的分布与国外有所不同。在我国A群和C群Nm菌株FHbp以V1为主,而在B群Nm菌株FHbp以V2为主。48株含有NadA的Nm菌株集中在ST-5complex和ST-11complex这两个克隆群中。44株ST-5complex Nm菌株中37株为A群,7株为C群；4株ST-11complex Nm菌株中3株为W135群,1株为NG。我国B群Nm菌株中不含有NadA。在美国和欧洲Nm主要的流行血清群B群菌株FHbp以V1为主,NadA常在B群和C群Nm菌株中发现。5CVMB中主要抗原成分FHbp和NadA对我国A群和C群Nm菌株能够有效的覆盖,但对B群Nm菌株覆盖率有限。因此,MenB蛋白疫苗应根据我国Nm菌株中抗原成分特征进行研发。本研究建立和优化了Nm对HEp-2人喉癌上皮细胞的黏附实验方法,检测了我国主要流行的ST-4821克隆群C群菌株和NG Nm菌株对HEp-2细胞的黏附能力。初步研究结果显示,我国主要流行的ST-4821序列群C群Nm和NGNm菌株对HEp-2细胞的黏附能力存在差异性
[Abstract]:Neisseria meningitidisis (Nmm) is a gram-negative diplococcus, which mainly causes epidemic meningitis and septicemia.According to the difference of bacterial surface capsular polysaccharides, Nm was divided into 12 serogroups, among them, Acarb Con YW135 and X were the main serogroups causing meningococcal disease worldwide, and many of them were indistinguishable and were called indistinguishable strains of Nongroupable NGN (NongroupableNGstrain).Meningitis is a disease which can be prevented by vaccine, and capsule polysaccharide is the main antigen component of the vaccine. At present, there are polysaccharide vaccine and polysaccharide protein conjugate vaccine of ACCW135 and Y group. The application of the vaccine reduces the morbidity and mortality of meningitis.Because of the weak immunogenicity of capsule polysaccharides of Neisseria meningitidis serogroup B Meningococcus (Menb), and the homology between sialic acid structure of capsule polysaccharide and human neuronal adhesion factor, immunization may cause autoimmunity.It is generally believed that capsular polysaccharide is not suitable for the development of MenB vaccine.In recent years, the research work of MenB protein vaccine has been carried out in the world.The MenB protein vaccine 5CVMB(5Component Vaccine against Meningococcus B).5CVMB was developed by reverse vaccinology. It consists of five antigen components of Neisseria meningitidis: Nisseria nisseria Adhetin Agnad Agna factor H binding protein FHbpPU GNA2091, Neisseria heparin binding antigen NhbAand GNA1030.The five antigenic components of MenB protein vaccine 5CVMB not only exist in Menb, but also exist in non-B group Nm strains. 5CVMB can not only prevent Menb, but also prevent Nm from other serum groups.It can be used as a universal vaccine to prevent Nm from different serum groups.In this study, the distribution and amino acid sequence polymorphism of protein vaccine antigen gene of different serogroup Nm strains in China were studied in order to understand the mutual coverage between MenB protein vaccine and Nm strain in China.The results showed that only 48 of the four Nm strains of FHbpnhbagna1030 and gna2091. 210 contained nadA gene, among which 44 Nm strains belonged to ST-5complex4 Nm strains belonging to ST-11complex. the results showed that there were only 48 Nm strains in different serogroups of China, and only 48 strains of Nm strains containing nadA gene, among them, 44 Nm strains belonged to ST-5complex4 Nm strains, which belonged to ST-11complex.The amino acid sequence of 48 NadA positive strains was analyzed.The fHbp gene of 110 Nm strains was sequenced. 49 strains (44.55) were composed of FHbp V1 (52 strains, 47.27) and 9 strains of FHbp V2 (9 strains, 8.18), which were FHbp V3o.The distribution of the main antigen components FHbp and NadA subtypes of 5CVMB in different serogroup Nm strains in China is different from that in foreign countries.The FHbp of group A and group C Nm in China was mainly V1.While in group B Nm FHbp, V2 was the dominant strain. 48 Nm strains containing NadA were concentrated in the two clone groups of ST-5complex and ST-11complex. 37 of 44 ST-5complex Nm strains were group A, 7 were group C, 4 were ST-11complex Nm, 3 were W135, 1 was NG.NadA was not found in Nm strains of group B in China.In the United States and Europe, the main prevalent serogroup B strain FHbp was V1. The main antigen components FHbp and NadA in group B and group C Nm were found to be able to effectively cover the strains of group A and group C in China.But the coverage of group B Nm was limited.Therefore, Menb protein vaccine should be developed according to the characteristics of antigen components of Nm strains in China.In this study, the adhesion of Nm to HEp-2 human laryngeal carcinoma epithelial cells was established and optimized, and the adhesion ability of ST-4821 clone group C and NG Nm strains to HEp-2 cells was tested.The preliminary results show that the adhesion ability of the main ST-4821 sequence group C group Nm and NGNm strain to HEp-2 cells is different.
【学位授予单位】：中国疾病预防控制中心
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R392

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