Department of Microbiology and Immunology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA.
Marsico Lung Institute, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA.
mSphere. 2024 Jun 25;9(6):e0008124. doi: 10.1128/msphere.00081-24. Epub 2024 Jun 5.
In a healthy colon, the stratified mucus layer serves as a crucial innate immune barrier to protect the epithelium from microbes. Mucins are complex glycoproteins that serve as a nutrient source for resident microflora and can be exploited by pathogens. We aimed to understand how the intestinal pathogen, , independently uses or manipulates mucus to its benefit, without contributions from members of the microbiota. Using a 2-D primary human intestinal epithelial cell model to generate physiologic mucus, we assessed mucus interactions through growth assays, RNA-Seq, biophysical characterization of mucus, and contextualized metabolic modeling. We found that host-derived mucus promotes growth both and in an infection model. RNA-Seq revealed significant upregulation of genes related to central metabolism in response to mucus, including genes involved in sugar uptake, the Wood-Ljungdahl pathway, and the glycine cleavage system. In addition, we identified differential expression of genes related to sensing and transcriptional control. Analysis of mutants with deletions in highly upregulated genes reflected the complexity of -mucus interactions, with potential interplay between sensing and growth. Mucus also stimulated biofilm formation , which may in turn alter the viscoelastic properties of mucus. Context-specific metabolic modeling confirmed differential metabolism and the predicted importance of enzymes related to serine and glycine catabolism with mucus. Subsequent growth experiments supported these findings, indicating mucus is an important source of serine. Our results better define responses of to human gastrointestinal mucus and highlight flexibility in metabolism that may influence pathogenesis.
results in upward of 250,000 infections and 12,000 deaths annually in the United States. Community-acquired infections continue to rise, and recurrent disease is common, emphasizing a vital need to understand pathogenesis. undoubtedly interacts with colonic mucus, but the extent to which the pathogen can independently respond to and take advantage of this niche has not been explored extensively. Moreover, the metabolic complexity of remains poorly understood but likely impacts its capacity to grow and persist in the host. Here, we demonstrate that uses native colonic mucus for growth, indicating possesses mechanisms to exploit the mucosal niche. Furthermore, mucus induces metabolic shifts and biofilm formation in , which has potential ramifications for intestinal colonization. Overall, our work is crucial to better understand the dynamics of -mucus interactions in the context of the human gut.
在健康的结肠中，分层的黏液层作为一种至关重要的先天免疫屏障，保护上皮免受微生物的侵害。黏蛋白是一种复杂的糖蛋白，可为常驻微生物群提供营养，并可被病原体利用。我们旨在了解肠道病原体 如何独立地利用或操纵黏液来为其所用，而不依赖于微生物群的成员。我们使用二维原代人肠上皮细胞模型生成生理黏液，通过生长测定、RNA-Seq、黏液的生物物理特性分析以及上下文相关代谢建模来评估黏液相互作用。我们发现，宿主来源的黏液促进了 和 在感染模型中的生长。RNA-Seq 显示，对黏液的反应显著上调了与中心代谢相关的基因，包括参与糖摄取、伍德-吕格达尔途径和甘氨酸裂解系统的基因。此外，我们还发现了与感应和转录控制相关的基因表达差异。对高度上调基因缺失突变体的分析反映了 -黏液相互作用的复杂性，感应和生长之间可能存在相互作用。黏液还刺激 生物膜的形成 ，这可能反过来改变黏液的粘弹性。上下文特定的代谢建模证实了代谢的差异，并预测了与丝氨酸和甘氨酸分解代谢相关的酶在黏液中的重要性。随后的生长实验支持了这些发现，表明黏液是丝氨酸的重要来源。我们的研究结果更好地定义了 对人胃肠道黏液的反应，并强调了代谢的灵活性，这可能会影响发病机制。
在美国每年导致超过 25 万例感染和 12000 例死亡。社区获得性感染继续上升，疾病反复发作很常见，这强调了迫切需要了解 发病机制。 无疑与结肠黏液相互作用，但病原体能否独立地对这一生态位作出反应并从中获益，尚未得到广泛探索。此外， 代谢的复杂性仍知之甚少，但可能会影响其在宿主中生长和持续存在的能力。在这里，我们证明 利用天然的结肠黏液进行生长，表明 具有利用黏膜生态位的机制。此外，黏液诱导 中的代谢转变和生物膜形成，这对肠道定植有潜在影响。总的来说，我们的工作对于更好地了解人类肠道中 -黏液相互作用的动态至关重要。
