Neisseria meningitidis antigens expressed in infection

感染中表达的脑膜炎奈瑟菌抗原

• 批准号: 6897257
• 负责人: Dan M. Granoff
• 金额: $ 24.02万
• 依托单位: CHILDREN'S HOSPITAL & RES CTR AT OAKLAND
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-06-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6897257
• 关键词: Neisseria meningitidis; antigen antibody reaction; bacterial antigens; bacterial genetics; bacterial meningitis; bacterial proteins; biological models; clinical research; disease /disorder model; disease /disorder prevention /control; enzyme linked immunosorbent assay; flow cytometry; gene expression; gene expression profiling; gram negative bacteria; human subject; infant animal; laboratory mouse; laboratory rat; microorganism culture; pathologic process; patient oriented research; protein purification; recombinant proteins; septicemia; vaccine development

DESCRIPTION (provided by applicant): N. meningitidis is an important cause of meningitis and sepsis. Conventional approaches to develop a vaccine for prevention of disease caused by capsular group B strains, which account for 30-80% of all cases, have been largely unsuccessful, and therefore there is a need for the identification of new vaccine candidates. To date, all candidate antigens have been identified using organisms grown in artificial media or on epithelial or endothelial cell monolayers. Little is known, however, about the gene expression profile of N. meningitidis during infection in vivo. Our hypothesis is that N. meningitidis grown in the infant rat model of bacteremia or in human whole blood will show specific genes that are up-regulated or activated compared to those expressed in artificial culture. Furthermore, genes that are up-regulated during invasive infection that encode novel proteins that are conserved in N. meningitidis, and that are predicted to be surface-accessible, will be promising vaccine candidates. We propose to use quantitative real-time PCR to study the temporal gene expression profile of N. meningitidis isolated from the bloodstream of infected infant rats and from the human blood infection model at different time-points, and also to compare the respective expression profiles with those of bacteria grown in broth. We will evaluate the immunogenicity of the recombinant proteins as purified His-tagged or GST-fusion proteins, and as "native" proteins in E. coli outer membrane vesicles. Antisera from immunized mice will be analyzed by ELISA, FACS, serum bactericidal activity, and passive protection in the infant rat model. The proposed studies may identify new antigens capable of eliciting broadly protective antibody for prevention of N. meningitidis disease, including group B strains for which there is currently no vaccine available. Also, characterization of gene expression in an in vivo model will lead to a better understanding of meningococcal pathogenesis.

描述（由申请人提供）：N。脑膜炎是脑膜炎和败血症的重要原因。开发疫苗预防由囊囊B组菌株引起的疾病的常规方法，占所有病例的30-80％，这在很大程度上没有成功，因此需要鉴定新的疫苗候选者。迄今为止，已经使用在人工培养基或上皮或内皮细胞单层中生长的生物鉴定出所有候选抗原。然而，关于体内感染过程中脑膜炎链球菌的基因表达谱鲜为人知。我们的假设是，与在人工培养物中表达的细菌相比，在菌血症或人类全血的婴儿大鼠模型或人类全血中生长的脑膜炎链球菌将显示出上调或激活的特定基因。此外，在侵入性感染过程中被上调的基因编码在脑膜炎链球菌中保守的新型蛋白质，并且预计可表面可访问的基因将是有希望的疫苗候选者。我们建议使用定量的实时PCR研究从感染婴儿大鼠的血液中分离出的脑膜炎的颞基因表达谱，并在不同的时间点上从人类血液感染模型中分离出来，并比较各自的表达谱与肉体中种植的细菌的表达谱。我们将评估重组蛋白的免疫原性为纯化的His标记或GST融合蛋白，并将其作为大肠杆菌外膜囊泡中的“天然”蛋白。免疫小鼠的抗血清将通过ELISA，FACS，血清杀菌活性和婴儿大鼠模型中的被动保护分析。拟议的研究可能会发现能够引起广泛保护性抗体的新抗原，以预防脑膜炎链球菌疾病，包括目前尚无疫苗的B组菌株。同样，体内模型中基因表达的表征将使人们更好地理解脑膜炎球菌发病机理。