Identification of vaccine antigens based on expression in blood

根据血液中的表达鉴定疫苗抗原

基本信息

批准号：
7690935
负责人：
Peter T. BEERNINK
金额：
$ 40万
依托单位：
CHILDREN'S HOSPITAL & RES CTR AT OAKLAND
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-09-24 至 2012-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7690935
关键词：
Affinity Amino Acids Animal Model Antibodies Antigens Bacteremia Bacteria Bacterial Genes Bacterial Genome Bacterial Meningitis Bacterial RNA Bacterial Vaccines Binding Biological Assay Blood Blood donor Blood-Borne Pathogens Complement Complement 3b DNA Microarray Chip Data Deposition Disease Encapsulated Enzyme-Linked Immunosorbent Assay Escherichia coli Gene Expression Genes Genetic Transcription Genomics Host Defense Human Immune Sera Immune response Immunity Infant Infection Laboratories Life Measures Mediating Membrane Meningitis Meningococcal vaccine Methods Modeling Mus Nature Neisseria gonorrhoeae Neisseria meningitidis Organism Plasma Prevention Proteins Public Health Rattus Reading Recombinant Proteins Reverse Transcription Sepsis Serological Serum Surface Testing Transcript Vaccine Antigen Vaccines Vascular System Vesicle Virulence Virulence Factors Whole Blood bactericide base cell envelope design disorder prevention genome sequencing immunogenicity in vivo Model novel novel strategies novel vaccines pathogen vaccine candidate

项目摘要

DESCRIPTION (provided by applicant): Complete genome sequences enable new approaches for antigen discovery. We propose to test a novel approach that uses bacterial genomes to identify candidate vaccine antigens that are up-regulated when bacteria are grown under conditions that mimic human infection. Our hypothesis is that genes that are up- regulated will include novel, surface-exposed antigens that may have gone unrecognized by previous studies of bacteria grown in artificial media. To test our hypothesis, we will use Neisseria meningitidis group B (NmB), an important cause of bacterial meningitis and sepsis, for which there is no broadly protective vaccine available. NmB is ideal for this purpose since in nature it exclusively infects humans; its hallmark is rapid replication in blood; and there exists a reliable serologic surrogate for predicting protective immunity, serum bactericidal activity. In Aim 1, we will perform transcriptional profiling using a combination of DNA microarrays and quantitative, reverse-transcription PCR to identify genes that are up-regulated when bacteria are grown in human blood or plasma. In Aim 2, we will identify genes that are up-regulated in bacteria isolated from infant rats with bacteremia. In Aim 3 we will express recombinant proteins encoded by NmB genes that are up- regulated during infection and, based on genomic data, are predicted to be conserved and surface-exposed. Mice will be immunized and the resulting antisera assayed for complement-mediated bactericidal activity against a panel of genetically diverse group B strains. Selected antisera will be tested for passive protection in the human blood ex vivo infection model and/or infant rat bacteremia model. The results may identify a new promising NmB vaccine candidate as well as determine whether similar transcription profiling studies have the potential for identifying vaccine antigens for other bloodborne pathogens. Project Narrative / Significance: We propose to evaluate a novel transcriptional profiling approach for discovery of vaccine antigens against bloodborne pathogens. We will employ Neisseria meningitidis group B, which is an ideal model organism to test our approach since it causes sepsis and meningitis exclusively in humans, no broadly protective vaccine is available and there exists a reliable serologic surrogate for predicting protective immunity. Our results may identify a new promising vaccine candidate for prevention of meningococcal disease, an important public health problem, as well as determine whether it is worth testing a similar approach for antigen discovery against other pathogens.

描述（由申请人提供）：完整的基因组序列使抗原发现的新方法成为可能。我们建议测试一种新方法，使用细菌基因组来识别候选疫苗抗原，当细菌在模拟人类感染的条件下生长时，这些抗原会上调。我们的假设是，上调的基因将包括新的、表面暴露的抗原，这些抗原可能未被先前对人工培养基中生长的细菌的研究所识别。为了检验我们的假设，我们将使用 B 组脑膜炎奈瑟菌 (NmB)，它是细菌性脑膜炎和败血症的重要原因，目前尚无广泛的保护性疫苗。 NmB 非常适合此目的，因为在自然界中它只感染人类。其特点是在血液中快速复制；并且存在可靠的血清学替代指标来预测保护性免疫、血清杀菌活性。在目标 1 中，我们将结合 DNA 微阵列和定量逆转录 PCR 进行转录分析，以识别细菌在人血液或血浆中生长时上调的基因。在目标 2 中，我们将鉴定从患有菌血症的幼鼠中分离出的细菌中上调的基因。在目标 3 中，我们将表达由 NmB 基因编码的重组蛋白，这些蛋白在感染过程中上调，并且根据基因组数据，预计是保守的和表面暴露的。对小鼠进行免疫，并检测所得抗血清针对一组遗传多样性 B 菌株的补体介导的杀菌活性。将测试选定的抗血清在人血液离体感染模型和/或幼鼠菌血症模型中的被动保护作用。结果可能会鉴定出一种新的有前景的 NmB 候选疫苗，并确定类似的转录谱研究是否有可能鉴定其他血源性病原体的疫苗抗原。项目叙述/意义：我们建议评估一种新的转录分析方法，用于发现针对血源性病原体的疫苗抗原。我们将采用 B 组脑膜炎奈瑟菌，它是测试我们方法的理想模型生物，因为它仅在人类中引起败血症和脑膜炎，没有广泛的保护性疫苗可用，并且存在可靠的血清学替代品来预测保护性免疫。我们的结果可能会确定一种新的有前途的候选疫苗，用于预防脑膜炎球菌病（这是一个重要的公共卫生问题），并确定是否值得测试针对其他病原体的抗原发现的类似方法。