Gut microflora: Impact on neonatal immunity, viral gastroenteritis and vaccines

肠道菌群：对新生儿免疫力、病毒性胃肠炎和疫苗的影响

• 批准号: 8287826
• 负责人: Gireesh Rajashekara
• 金额: $ 41.5万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8287826
• 关键词: Address; Adjuvant; Adoption; Affect; African; Allergic; Anaerobic Bacteria; Anatomy; Animal Model; Animals; Anti-Inflammatory Agents; Anti-inflammatory; Antibiotic Therapy; Antibiotics; Antibodies; Attenuated; Bacteria; Biological Markers; Biological Products; Birth; Cessation of life; Child; Childhood; Collaborations; Communicable Diseases; Competence; Complex; Confounding Factors (Epidemiology); Country; Data; Developed Countries; Developing Countries; Development; Diarrhea; Diet; Disease; Economics; Effectiveness; Enteral; Epithelial Cells; Equilibrium; Escherichia coli; Expressed Sequence Tags; Family suidae; Food Hypersensitivity; Gene Expression Profile; Genes; Gnotobiotic; Goals; Homeostasis; Human; Hypersensitivity; Immune; Immune response; Immune system; Immunity; Immunoglobulin A; Inbreeding; Incidence; Indigenous; Infant; Infant Health; Infantile Diarrhea; Infection; Inflammation; Inflammatory; Inflammatory Bowel Diseases; Inflammatory Response; Intestines; Investigation; Knowledge; Kwashiorkor; Lactobacillus; Lactobacillus acidophilus; Lead; Licensing; Life; Malnutrition; Maternal antibody; Mediating; Metagenomics; Microarray Analysis; Microbe; Milk; Modeling; Morbidity - disease rate; Mothers; Mucosal Immunity; Mus; Neonatal; Newborn Animals; Oral; Pathogenesis; Pathogenicity; Pathway interactions; Permeability; Physiology; Play; Predisposition; Probiotics; Property; Public Health; Recovery; Regulation; Regulatory T-Lymphocyte; Resistance; Role; Rotavirus; Rotavirus Infections; Rotavirus Vaccines; Rotavirus disease; Serum; Severities; Severity of illness; Symptoms; Syndrome; Testing; Therapeutic Intervention; Tight Junctions; Transplantation; Treatment Cost; Twin Multiple Birth; Vaccinated; Vaccine Adjuvant; Vaccine Design; Vaccines; Viral; Viral Gastroenteritis; Viral Vaccines; Virulent; Virus; Weaning; base; commensal microbes; cost; experience; feeding; food antigen; gene function; gut microbiota; gut microflora; high risk infant; immunoregulation; improved; innovation; insight; metabolomics; microbial; microbiome; mortality; neonate; oral vaccine; response; sugar; vaccine efficacy

DESCRIPTION (provided by applicant): Rotavirus (RV) is a leading global cause of childhood diarrhea. Current attenuated human RV (AttHRV) oral vaccines are effective in infants in developed countries, but for unexplained reasons, they lack efficacy in impoverished countries where diarrhea mortality is highest. Alternative affordable strategies are urgently needed to reduce diarrheal diseases and enhance oral vaccine efficacy. Malnutrition (kwashiorkor) and frequent antibiotic usage in infants affect the gut microbiome and barrier integrity, likely compromising gut immunity and predisposing infants to diarrheal illness, but their impact on HRV infection is uncharacterized. Studies of gnotobiotic (Gn) animals have revealed that probiotics or commensal microflora are crucial for gut immune maturation and homeostasis, but the mechanisms involved and their roles in modulating viral diarrheas or enhancing oral vaccine efficacy are unclear. Neonates undergo progressive changes in the gut microflora which we will model by colonizing Gn pigs with Lactobacillus spp (Gram, G+), E. coli (G- ), both, or a commensal cocktail from conventional piglets. Gn pigs resemble infants in size, anatomy, physiology, development of mucosal immunity and are the only animal model susceptible to HRV diarrhea. Our investigation of how the selected probiotics/commensals modulate gut homeostasis and immune responses and impact enteric diseases and vaccines will permit their rational use as biotherapeutic agents and/or adjuvants. We hypothesize that selected G+ and G- gut microflora will modulate different host cellular pathways leading to immunostimulatory, but balanced (Th1/Th2/Th17/Treg) responses that enhance efficacy of RV vaccines or immuno-regulatory (Treg) responses that moderate HRV diarrhea. Further, humanized, outbred Gn pigs are a unique model to study how microbiota and diet contribute to malnutrition and HRV disease severity under conditions that constrain confounding variables in ways not possible in infants. In Aim 1, we determine how selected G+ or G- probiotics, both, or the commensal cocktail modulates immune responses, gut homeostasis and HRV pathogenicity. Then we test the impact of antibiotics on the commensal microflora and on these same parameters. In Aim 2, we determine how defined probiotics or commensals modulate protective immunity to AttHRV oral vaccine. In Aim 3, in collaboration with Jeff Gordon, we develop a humanized Gn pig model to study the interaction of microbiota x diet (from African twins discordant for kwashiorkor) on severe malnutrition and HRV pathogenicity and identify microbial biomarkers to aid in vaccine design or therapeutic interventions. Effects of the probiotics/commensals/microbiota will be compared by intestinal transcriptome profiling (pig microarrays, 44K ESTs), metagenomics, metabolomics and metatranscriptomics, gut barrier integrity (sugar permeability, tight junction genes, serum LPS), and induction of innate and adaptive immune responses, to establish the immunoregulatory/immunostimulatory profiles. Our innovative studies will address gaps in knowledge of gut immune maturation and homeostasis and interactions between gut microflora and enteropathogenic viruses or oral vaccines. Our findings will contribute to alternative low cost probiotic treatments applicable to infants (or mothers) to moderate HRV disease, enhance oral vaccine efficacy, and reduce infant morbidity and mortality. PUBLIC HEALTH RELEVANCE: Human rotavirus (HRV) is a leading cause of childhood diarrhea worldwide. The high costs and unexplained low effectiveness of licensed oral HRV vaccines in infants in impoverished countries remain obstacles to their universal adoption. Alternative low cost treatments to moderate HRV disease and enhance effectiveness of RV and other oral vaccines are needed to reduce infant diarrheal diseases and deaths. A balanced, healthy gut microflora containing Gram positive (Lactobacillus sp) and Gram negative (E. coli) bacteria plays a crucial role in maturation of the neonatal intestinal and systemic immune systems. It is also critical for development of post-natal immune competence and resistance to infectious diseases or allergic and inflammatory bowel syndromes. Our goal is to use harmless probiotic or commensal microbes to confer beneficial effects to infant health via immune stimulation (pro-inflammatory strains to enhance vaccines) or immune regulation [anti-inflammatory strains to reduce inflammation (diarrhea, allergies, inflammatory bowel diseases)]. Our unique germfree (GF) pig model is derived free of confounding microbes and maternal antibodies. Neonatal GF pigs resemble infants in size, physiology, anatomy, susceptibility to HRV diarrhea and development of mucosal immunity. Results from our proposed studies will elucidate how a known Gram positive probiotic, a Gram negative commensal, or both, and a defined commensal mixture influence neonatal intestinal homeostasis and immune maturation, and consequently moderate HRV diarrhea or enhance effectiveness of attenuated HRV oral vaccines. Factors such as antibiotics and diet (malnutrition) can disrupt the gut microflora, influencing susceptibility to diarrheal diseases and the effectiveness of oral vaccines, but in undefined ways. Using the GF pig model, we will determine the impact of antibiotic treatment, commonly used in infants and children, on the gut microflora, neonatal immune responses and the severity of HRV diarrhea. With our collaborator, we will further develop a humanized GF pig model (transplanted microflora from African twins) to define the role of microflora and native diet on the development of severe forms of malnutrition such as kwashiorkor, seen in African children. We will then explore how severe malnutrition affects diarrhea and deaths associated with HRV, to discern the basis for the disproportionately high mortality rates in HRV-infected children in developing countries. Collectively these studies will identify potential microbial biomarkers that will aid in design of vaccines or therapeutic interventions, including dietary manipulations. Understanding how neonatal immune responses can be modulated in the context of probiotics and the gut microflora has important implications for public health. These include not only increasing neonatal immunity to viral vaccines and diarrheas, but also treatments for malnutrition and antibiotic-induced diarrheas, as well as for induction of tolerance to food antigens and our indigenous microflora, to control the increasing incidence of food allergies and inflammatory bowel syndromes, respectively.

描述（由申请人提供）：轮状病毒（RV）是儿童腹泻的全球主要原因。当前的人RV（ATTHRV）口服疫苗在发达国家的婴儿有效，但是由于无法解释的原因，在腹泻死亡率最高的贫困国家中，它们缺乏疗效。迫切需要采取替代性负担得起的策略来减少腹泻疾病并提高口服疫苗功效。婴儿的营养不良（kwashiorkor）和婴儿频繁的抗生素使用会影响肠道微生物组和屏障完整性，可能会损害肠道免疫力，并使婴儿诱发腹泻病，但它们对HRV感染的影响未经特征。 gnotobiotic（GN）动物的研究表明，益生菌或共生菌群对于肠道免疫成熟和稳态至关重要，但是所涉及的机制及其在调节病毒性腹泻或增强口服疫苗功效中的作用尚不清楚。新生儿经历了肠道菌群的进行性变化，我们将通过将GN猪与乳酸杆菌（Gram，G+），大肠杆菌（G-），或来自常规小猪的共生鸡尾酒进行建模。 GN猪类似于大小，解剖学，生理，粘膜免疫的发育，是唯一容易患有HRV腹泻的动物模型。我们对所选益生菌/份量如何调节肠道稳态以及免疫反应以及影响肠道疾病和疫苗的调查将使它们合理用作生物治疗剂和/或辅助因素。我们假设选定的G+和G-ut菌群将调节不同的宿主细胞途径，导致免疫刺激性，但平衡（TH1/TH2/TH17/TREG）响应，从而增强RV疫苗或免疫调节（TREG）反应的功效。此外，人性化的，杂种的GN猪是研究微生物群和饮食如何促进营养不良和HRV疾病严重程度的独特模型，这些条件在婴儿不可能以可能的方式限制了混淆变量的情况下。在AIM 1中，我们确定选择的G+或G-益生菌是如何调节免疫反应，肠稳态和HRV致病性的。然后，我们测试抗生素对共生菌群和这些相同参数的影响。在AIM 2中，我们确定定义的益生菌或共生如何调节对ATTHR口服疫苗的保护性免疫。在AIM 3中，与Jeff Gordon合作，我们开发了一种人源化的GN Pig模型，以研究严重营养不良和HRV的病原体的微生物X饮食（来自非洲双胞胎与Kwashiorkor的不一致）的相互作用，并确定微生物生物标志物以帮助疫苗设计或治疗性设计或治疗疗法设计或治疗性设计或治疗性生物标志物干预措施。益生菌/共生/微生物的影响将通过肠道转录组分析（猪微阵列，44K EST），宏基因组学，代谢组学和元文字分类组，肠道屏障完整性（糖渗透性，紧密连接基因，血清LPS，血清LPS），以及固定性的含量和适应性来比较。免疫反应，以建立免疫调节/免疫刺激谱。我们的创新研究将解决有关肠道免疫成熟和稳态知识的差距，以及肠道菌群与肠病病毒或口服疫苗之间的相互作用。我们的发现将有助于替代适用于婴儿（或母亲）适应中度HRV疾病，提高口服疫苗功效并降低婴儿的发病率和死亡率的替代性低成本益生菌治疗。 公共卫生相关性：人轮状病毒（HRV）是全球儿童腹泻的主要原因。贫困国家婴儿的持牌口服HRV疫苗的高成本和无法解释的低效力仍然是其普遍采用的障碍。需要为中度HRV疾病的替代性低成本处理，并提高RV和其他口服疫苗的有效性，以减少婴儿腹泻疾病和死亡。含有革兰氏阳性（乳杆菌SP）和革兰氏阴性（大肠杆菌）细菌的平衡，健康的肠道菌群在新生儿肠道和全身免疫系统的成熟中起着至关重要的作用。这对于产生产后免疫能力以及对感染性疾病或过敏性和炎症性肠综合征的抵抗力也至关重要。我们的目标是使用免疫刺激（促炎性菌株来增强疫苗）或免疫调节[抗炎菌株（抗炎菌株）来减少炎症（腹泻，过敏，炎症性肠道疾病），使用无害的益生菌或共生微生物对婴儿健康赋予有益的效果。 。我们独特的无毛（GF）猪模型被推导出无混杂的微生物和母体抗体。新生儿GF猪类似于大小，生理学，解剖学，对HRV腹泻的易感性和粘膜免疫发育的敏感性。我们提出的研究的结果将阐明已知的革兰氏阳性益生菌，革兰氏阴性分子或两者兼而有之以及确定的共生混合物会影响新生儿肠道稳态和免疫成熟，从而影响衰减HRV口服疫苗的有效性。抗生素和饮食（营养不良）等因素会破坏肠道菌群，影响腹泻疾病的敏感性和口服疫苗的有效性，但以不确定的方式。使用GF猪模型，我们将确定通常用于婴儿和儿童，肠道菌群，新生儿免疫反应和HRV腹泻的严重程度的抗生素治疗的影响。借助我们的合作者，我们将进一步开发人源化的GF猪模型（从非洲双胞胎移植的菌群）来定义微生物和天然饮食的作用 关于在非洲儿童中看到的严重营养不良形式的发展。然后，我们将探讨营养不良如何影响与HRV相关的腹泻和死亡，以辨别发展中国家HRV感染儿童死亡率不成比例的基础。这些研究总的来说，将确定潜在的微生物生物标志物，这些标志物将有助于设计疫苗或治疗性干预措施，包括饮食操纵。了解如何在益生菌和肠道菌群中调节新生儿免疫反应对公共卫生具有重要意义。这些不仅包括增加对病毒疫苗和腹泻的新生儿免疫，还包括营养不良和抗生素诱导的腹泻的治疗方法，以及诱导耐受性 分别控制食物抗原和我们的土著菌群，分别控制食物过敏和炎症肠综合征的发生率的增加。