Mechanisms of Corynebacterium-Dolosigranulum Interactions that Shape Human Nasal Microbiota

我们两个NIGMS资助研究领域的目标是确定潜在的分子机制， 微生物-微生物和微生物-宿主相互作用涉及D. pigrum和鼻棒状杆菌物种， 塑造人类鼻腔微生物群。有证据表明，棒状杆菌属和Dolosigranulum 猪在构建有益于人类健康的鼻微生物群中起关键作用。例如，高血压患者 水平的棒状杆菌和/或D.鼻内微生物群中的pigrum不太可能被致病菌定殖 因此，在他们身体的其他部位中，侵入性感染的风险较低。同样，鼻腔微生物 以棒状杆菌属/D. pigrum通常与健康有关，而不是与疾病有关， 中耳炎和肺炎。我们的总体假设是，D。pigrum和 棒状杆菌属物种驱动有益的健康促进人类鼻腔微生物群。这其中的一个核心目标 研究是从成分数据的相关性转移到因果关系，通过识别分子机制， 是体内关联和体外表型的基础。我们的NIGMS支持的初步数据显示， 有四种常见的鼻棒状杆菌。其中3个与D.皮格伦 增强D.猪的体外生长。此外，还研究了D.猪棒状杆菌 pseudoditheriticum一起强烈抑制S. pneumoniae在体外，与单独使用相比。D. Pigrum还 抑制S.金黄色葡萄球菌体外生长。这些体外结果支持了体内相互作用与潜在健康的作用 效益为了了解人类鼻腔中微生物-微生物和微生物-上皮的相互作用，我们 将在空气-液体界面（aka nasanoids）使用人类鼻上皮类器官作为创新的仿生 与我们的类器官核心合作的模型系统。微生物群落的特点是由一个网络， 微生物之间以及与环境之间的代谢相互作用。基因组分析发现D.皮格伦 营养缺陷型表明它依赖于宿主或微生物邻居的关键营养。我们的研究将解决 在理解支持人类鼻腔微生物群的食物网方面存在差距; 宿主微生物;以及潜在有益鼻细菌的生理学和功能。的一个关键优势 使用人类鼻腔微生物群来识别代谢相互作用的原因是，它是一种独立的细菌-上皮细胞 关于营养素。我们将使用互补的方法，包括泛基因组学，代谢 建模、双重细菌-上皮转录组学、代谢组学和基因工程。我们还将解决 鼻微生物组领域的关键技术挑战，以促进代谢物，蛋白质和 参与相互作用的基因为进一步研究D. pigrum和鼻棒状杆菌，我们有 从超过400名各年龄段的志愿者中建立了大量的鼻细菌培养物。通过识别代谢 鼻棒状杆菌属物种之间的相互作用，D. pigrum，和鼻上皮，塑造一个健康的， 促进人类鼻腔微生物群，我们希望催化预防感染的新方法。

The objective unifying our two areas of NIGMS-funded research is to identify molecular mechanisms underlying microbe-microbe and microbe-host interactions involving D. pigrum and nasal Corynebacterium species that shape the human nasal microbiota. Evidence indicates that Corynebacterium species and Dolosigranulum pigrum play key roles in structuring a nasal microbiota beneficial to human health. For example, people with high levels of Corynebacterium and/or D. pigrum in their nasal microbiota are less likely to be colonized by pathobionts and, therefore, are at lower risk of invasive infections in other parts of their bodies. Similarly, nasal microbiota dominated by Corynebacterium/D. pigrum are often associated with health rather than with diseases such as otitis media and pneumonia. Our overarching hypothesis is that interactions between D. pigrum and Corynebacterium species drive a beneficial health-promoting human nasal microbiota. A central goal of this research is to shift from correlations in compositional data to causation by identifying molecular mechanisms that underlie both in vivo associations and in vitro phenotypes. Our NIGMS-supported preliminary data show that there are four common species of nasal Corynebacterium. Three of these are positively correlated with D. pigrum and enhance D. pigrum growth in vitro. Furthermore, cocultivation of D. pigrum with Corynebacterium pseudodiphtheriticum together robustly inhibits S. pneumoniae in vitro, compared to either alone. D. pigrum also inhibits S. aureus growth in vitro. These in vitro results support a role for in vivo interactions with potential health benefits. To understand microbe-microbe and microbe-epithelium interactions in the human nasal passages, we will use human nasal epithelial organoids at an air-liquid interface (aka nasanoids) as an innovative biomimetic model system in collaboration with our Organoid Core. Microbial communities are characterized by a network of metabolic interactions among microbes and with the environment. Genomic analysis uncovered D. pigrum auxotrophies indicating it depends on the host or microbial neighbors for key nutrients. Our research will address gaps in understanding the food web that supports human nasal microbiota; the effects on the epithelium of hosting microbes; and the physiology and function of potentially beneficial nasal bacteria. A key advantage of using human nasal microbiota to identify metabolic interactions is that it is a self-contained bacterial-epithelial system with regard to nutrients. We will use complementary approaches including pan-genomics, metabolic modeling, dual bacteria-epithelium transcriptomics, metabolomics and genetic engineering. We will also tackle key technical challenges in the nasal microbiome field to facilitate identification of metabolites, proteins and genes involved in interactions. To advance research on D. pigrum and nasal Corynebacterium, we have established a large culture collection of nasal bacteria from > 400 volunteers of all ages. By identifying metabolic interactions between nasal Corynebacterium species, D. pigrum, and the nasal epithelium that sculpt a health- promoting human nasal microbiota, we hope to catalyze new approaches for preventing infection.