The human gut microbiome, malnutrition and vaccine responses

人类肠道微生物组、营养不良和疫苗反应

• 批准号: 8127100
• 负责人: Andrew Leon Kau
• 金额: $ 5.68万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-04 至 2014-07-03
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8127100
• 关键词: Address; Adjuvant; Age; Agriculture; Animals; Antigens; Archaea; Area; Bacteria; Biological Assay; Biological Markers; Birth; Cells; Cessation of life; Child; Childhood; Cholera Toxin; Communities; DNA; Defect; Development; Diet; Diet Monitoring; Endotoxins; Enteral; Enzyme-Linked Immunosorbent Assay; Excretory function; Exhibits; Failure; Family; Female; Fetal Malnutrition; Food; Freezing; Gene Expression; Genes; Germ-Free; Glean; Gnotobiotic; Harvest; Histology; Human; Immune; Immune system; Immunoglobulin A; Immunoglobulin G; Infant; Infection; Intervention; Intestines; Kwashiorkor; Lactulose; Lead; Life; Link; Longitudinal Studies; Macronutrients Nutrition; Malawi; Malnutrition; Mannitol; Messenger RNA; Metabolic; Metagenomics; Methods; Micronutrients; Modeling; Monitor; Monozygotic Twinning; Monozygotic twins; Morbidity - disease rate; Morphology; Mothers; Mucosal Immune Responses; Mucosal Immunity; Mus; National Research Service Awards; Neurodevelopmental Deficit; Nutrient; Nutritional; Nutritional Support; Nutritional status; Oral; Ovalbumin; Partner in relationship; Pathogenesis; Pattern; Physiological; Pneumonia; Population; Predisposition; Pregnancy; Protocols documentation; RNA; Recurrence; Relative (related person); Ribosomal RNA; Role; Sampling; Series; Serum; Shapes; Shotguns; Siblings; Structure; Surveys; Testing; Therapeutic; Therapeutic Uses; Time; Translations; Transplantation; Twin Multiple Birth; Vaccinated; Vaccination; Vaccine Design; Vaccines; Weaning; Withdrawal; absorption; aged; design; disorder risk; expectation; feeding; functional genomics; global health; gut microbiota; immune function; insight; killings; member; microbial; microbial community; microbiome; micronutrient deficiency; mortality; mouse model; mucosal vaccination; offspring; postnatal; pregnant; pup; rRNA Genes; research study; response; transmission process

DESCRIPTION (provided by applicant): Malnutrition kills millions of children worldwide every year. Much of their morbidity and mortality is a result of infections, including those caused by enteropathogens. Efforts to stop these infections have been limited in some populations by unexplained vaccine failures. I hypothesize that there is an interrelationship between malnutrition, the gut microbiome, and the immune system that is causally linked with vaccine responsiveness and that these interrelationships can be informatively probed using 'humanized' gnotobiotic mice. Our lab is conducting longitudinal studies of the gut microbiomes of twins aged 1-36 months living in Malawi who are healthy, or who are concordant or discordant for severe forms of malnutrition (e.g., kwashiorkor). We are addressing the following questions: Are there identifiable configurations of the gut microbiome associated with severe forms of malnutrition? How is the microbiota/microbiome reconfigured with a Ready to Use Therapeutic Food (RUTF) intervention and does it persist after cessation of RUTF? If the configured state does not persist after withdrawal of RUTF, does this mean that in the absence of longer-term nutritional support, lingering abnormalities in the metabolic activities contribute to persistent physiological abnormalities in the human host? We have recently shown that it is possible to efficiently transplant the microbial community present in frozen human fecal samples into germ-free (GF) mice and to transmit the engrafted microbiota from mothers to their offspring. With this capability, I propose two aims for this NRSA application. Aim 1. Use gnotobiotic mice, colonized at 6 weeks of age with de-identified fecal microbiota already collected from several sets of monozygotic twins discordant for kwashiorkor (1 healthy/ 1 malnourished) as well as their mothers' microbiota. Recipients will be fed a macro- and micronutrient deficient Malawi diet, or a control nutritionally 'sufficient' diet. I will follow their responses to mucosal vaccination with cholera toxin and ovalbumin (a model mucosal adjuvant/antigen) using antigen-specific ELISA. I will define their gut mucosal barrier function by serum LPS assays, lactulose/mannitol absorption assays, histo- and immunohistochemical assays of gut morphology and immune cell populations (exploring whether they have features of tropical enteropathy), plus functional genomic studies of gut gene expression. I will perform time series metagenomic studies on their fecal microbiomes (sequencing bacterial 16S rRNA genes, total community DNA, and expressed mRNAs). Aim 2. Assess the role of maternal nutritional and microbiota 'status' on the vaccine responses of their offspring by colonizing pregnant female GF mice with fecal samples from twins discordant for kwashiorkor and their mothers. Mothers will be maintained on either a Malawi or nutrient- sufficient control diet prior to, during and after pregnancy; their offspring will be weaned onto nutrient- deficient or -sufficient diets and subjected to the same vaccination protocols and analyses as described in Aim 1. These experiments should help identify biomarkers of malnutrition and vaccine responsiveness. PUBLIC HEALTH RELEVANCE: Tragically, malnutrition is the leading cause of childhood death worldwide. To understand why malnourished children fail to respond to potentially life-saving vaccines, we are using gnotobiotic mice, colonized with the gut microbial communities harvested from monozygotic twins living in Malawi who are discordant for severe malnutrition, in order to characterize responses to oral vaccination as a function of diet and gut microbial community structure, with the expectation that translation of information gleaned from this mouse model will provide new mechanistic insights and therapeutic strategies for enhancing vaccine responses in vulnerable pediatric populations.

描述（由申请人提供）：营养不良每年导致全世界数百万儿童死亡。其大部分发病率和死亡率是感染造成的，包括肠道病原体引起的感染。由于不明原因的疫苗失败，阻止这些感染的努力在某些人群中受到限制。我假设营养不良、肠道微生物群和免疫系统之间存在相互关系，与疫苗反应性存在因果关系，并且可以使用“人源化”无菌小鼠对这些相互关系进行翔实的探索。我们的实验室正在对生活在马拉维的 1-36 个月大双胞胎的肠道微生物组进行纵向研究，这些双胞胎健康，或者严重营养不良（例如恶性营养不良）一致或不一致。我们正在解决以下问题：肠道微生物组的可识别配置是否与严重营养不良相关？即用型治疗性食品 (RUTF) 干预措施如何重新配置​​微生物群/微生物组，以及在 RUTF 停止后这种情况是否持续存在？如果停用RUTF后配置状态没有持续存在，这是否意味着在缺乏长期营养支持的情况下，代谢活动的持续异常会导致人类宿主持续的生理异常？我们最近表明，可以有效地将冷冻人类粪便样本中存在的微生物群落移植到无菌（GF）小鼠中，并将移植的微生物群从母亲传给后代。有了这个功能，我为这个 NRSA 应用提出了两个目标。目标 1. 使用 6 周龄定植的无菌小鼠，其粪便微生物群已从几组与恶性营养不良（1 名健康/1 名营养不良）不一致的同卵双胞胎及其母亲的微生物群中收集。接受者将接受缺乏大量营养素和微量营养素的马拉维饮食，或营养“充足”的对照饮食。我将使用抗原特异性 ELISA 跟踪他们对霍乱毒素和卵清蛋白（一种粘膜佐剂/抗原模型）粘膜疫苗接种的反应。我将通过血清 LPS 测定、乳果糖/甘露醇吸收测定、肠道形态和免疫细胞群的组织和免疫组织化学测定（探索它们是否具有热带肠病的特征）以及肠道基因表达的功能基因组研究来定义它们的肠道粘膜屏障功能。我将对它们的粪便微生物组进行时间序列宏基因组研究（对细菌 16S rRNA 基因、总群落 DNA 和表达的 mRNA 进行测序）。目标 2. 通过将恶性营养不良双胞胎及其母亲的粪便样本定植怀孕雌性 GF 小鼠，评估母体营养和微生物群“状态”对其后代疫苗反应的作用。母亲在怀孕前、怀孕期间和怀孕后将保持马拉维饮食或营养充足的控制饮食；他们的后代将断奶，采用营养不足或营养充足的饮食，并接受与目标 1 中所述相同的疫苗接种方案和分析。这些实验应有助于识别营养不良和疫苗反应的生物标志物。 公共卫生相关性：可悲的是，营养不良是全世界儿童死亡的主要原因。为了了解为什么营养不良的儿童无法对可能挽救生命的疫苗做出反应，我们使用了无菌小鼠，这些小鼠的肠道微生物群落是从生活在马拉维的同卵双胞胎中收获的，这些双胞胎的严重营养不良情况不一致，以便将口服疫苗的反应描述为饮食和肠道微生物群落结构的函数，期望从该小鼠模型收集的信息的翻译将为增强脆弱儿科的疫苗反应提供新的机制见解和治疗策略人口。