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: 8460082
• 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/8460082
• 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; 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; infant morbidity/mortality; innovation; insight; intestinal homeostasis; 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.

描述（由申请人提供）：轮状病毒（RV）是全球儿童腹泻的主要原因。目前的减毒人类RV（AttHRV）口服疫苗对发达国家的婴儿有效，但由于不明原因，它们在腹泻死亡率最高的贫困国家缺乏效力。迫切需要替代的负担得起的策略来减少腹泻病并提高口服疫苗的功效。婴儿营养不良（恶性营养不良）和频繁使用抗生素会影响肠道微生物组和屏障完整性，可能损害肠道免疫力并使婴儿容易患腹泻病，但它们对 HRV 感染的影响尚不清楚。对无菌 (Gn) 动物的研究表明，益生菌或共生微生物群对于肠道免疫成熟和稳态至关重要，但其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。新生儿的肠道菌群会经历渐进性的变化，我们将通过用乳杆菌（革兰氏菌，G+）、大肠杆菌（G-）或来自传统仔猪的共生混合物定植 Gn 猪来模拟这种变化。 Gn 猪在体型、解剖学、生理学、粘膜免疫发育方面与婴儿相似，是唯一易患 HRV 腹泻的动物模型。我们对所选益生菌/共生菌如何调节肠道稳态和免疫反应以及影响肠道疾病和疫苗的研究将允许它们作为生物治疗剂和/或佐剂的合理使用。我们假设选定的 G+ 和 G- 肠道菌群将调节不同的宿主细胞途径，从而产生免疫刺激但平衡的 (Th1/Th2/Th17/Treg) 反应，从而增强 RV 疫苗的功效或缓解 HRV 腹泻的免疫调节 (Treg) 反应。此外，人源化、近亲繁殖的 Gn 猪是一种独特的模型，可用于研究微生物群和饮食如何在婴儿无法实现的混杂变量限制条件下导致营养不良和 HRV 疾病严重程度。在目标 1 中，我们确定选定的 G+ 或 G- 益生菌（两者）或共生混合物如何调节免疫反应、肠道稳态和 HRV 致病性。然后我们测试抗生素对共生微生物群和这些相同参数的影响。在目标 2 中，我们确定特定的益生菌或共生菌如何调节 AttHRV 口服疫苗的保护性免疫力。在目标 3 中，我们与 Jeff Gordon 合作开发了人源化 Gn 猪模型，以研究微生物群 x 饮食（来自与恶性营养不良不一致的非洲双胞胎）对严重营养不良和 HRV 致病性的相互作用，并确定微生物生物标志物以帮助疫苗设计或治疗干预措施。将通过肠道转录组分析（猪微阵列、44K EST）、宏基因组学、代谢组学和宏转录组学、肠道屏障完整性（糖渗透性、紧密连接基因、血清 LPS）以及先天和适应性诱导来比较益生菌/共生菌/微生物群的影响。免疫反应，建立免疫调节/免疫刺激谱。我们的创新研究将解决肠道免疫成熟和稳态以及肠道微生物群与肠道致病病毒或口服疫苗之间相互作用的知识空白。我们的研究结果将有助于开发适用于婴儿（或母亲）的替代性低成本益生菌治疗方法，以缓解 HRV 疾病，增强口服疫苗的功效，并降低婴儿的发病率和死亡率。