Abstract：
Bacterial infection is a dynamic process resulting in a heterogenous population of infected and uninfected cells. These cells respond differently based on their bacterial load and duration of infection. In the case of infection of macrophages with Crohn\'s disease (CD) associated adherent-invasive Escherichia coli (AIEC), understanding the drivers of pathogen success may allow targeting of cells where AIEC replicate to high levels. Here we show that stratifying immune cells based on their bacterial load identifies novel pathways and therapeutic targets not previously associated with AIEC when using a traditional homogeneous infected population approach. Using flow cytometry-based cell sorting we stratified cells into those with low or high intracellular pathogen loads, or those which were bystanders to infection. Immune cells transcriptomics revealed a diverse response to the varying levels of infection while pathway analysis identified novel intervention targets that were directly related to increasing intracellular AIEC numbers. Chemical inhibition of identified targets reduced AIEC intracellular replication or inhibited secretion of tumour necrosis factor alpha (TNFα), a key cytokine associated with AIEC infection. Our results have identified new avenues of intervention in AIEC infection that may also be applicable to CD through the repurposing of already available inhibitors. Additionally, they highlight the applicability of immune cell stratification post-infection as an effective approach for the study of microbial pathogens.
摘要：
细菌感染是一个动态过程，导致感染和未感染细胞的异质性群体。这些细胞基于它们的细菌负荷和感染持续时间而不同地响应。在感染巨噬细胞与克罗恩病（CD）相关的粘附性侵袭性大肠杆菌（AIEC）的情况下，了解病原体成功的驱动因素可能允许靶向AIEC复制至高水平的细胞。在这里，我们表明，根据其细菌负荷对免疫细胞进行分层，可以识别出使用传统的同质感染人群方法时以前与AIEC无关的新途径和治疗靶标。使用基于流式细胞术的细胞分选，我们将细胞分层为具有低或高细胞内病原体负荷的细胞。或者那些感染的旁观者。免疫细胞转录组学揭示了对不同水平的感染的不同反应，而通路分析确定了与增加细胞内AIEC数量直接相关的新干预目标。对已鉴定的靶标的化学抑制减少了AIEC细胞内复制或抑制了肿瘤坏死因子α（TNFα）的分泌，与AIEC感染相关的关键细胞因子。我们的研究结果确定了干预AIEC感染的新途径，通过重新利用已经可用的抑制剂，也可能适用于CD。此外,他们强调了感染后免疫细胞分层作为研究微生物病原体的有效方法的适用性。
