Evaluating the effect of spaceflight on the host-pathogen interaction between human intestinal epithelial cells and Salmonella Typhimurium

Spaceflight uniquely alters the physiology of both human cells and microbial pathogens, stimulating cellular and molecular changes directly relevant to infectious disease. However, the influence of this environment on host-pathogen interactions remains poorly understood. Here we report our results from the STL-IMMUNE pilot study flown aboard STS-131, which investigated multi-omic responses (transcriptomic, proteomic) of human intestinal epithelial cells to infection with Salmonella Typhimurium when both host and pathogen were simultaneously exposed to spaceflight. To our knowledge, this is the first in vitro in-flight infection and dual RNA-seq analysis using human cells. Overall design: Human colonic epithelial cells were cultured in hollow fiber bioreactors in space aboard Space Shuttle Discovery (mission STS-131). Synchronous ground controls were performed in the same hardware on Earth at Kennedy Space Center. On Flight Day 11, Salmonella Typhimurium (~1x10^7 CFU) was injected into a subset of the cultures while the remaining cultures served as time-matched uninfected controls. Six hours post-infection, cultures were fixed in RNAlater II for post-flight analysis.

太空飞行会特异性改变人类细胞与微生物病原体的生理状态，诱发与感染性疾病直接相关的细胞及分子水平变化。然而，目前学界对该太空环境如何影响宿主-病原体互作仍缺乏充分认识。本研究报告了搭载于STS-131任务的STL-IMMUNE先导试验结果：该试验探究了当宿主与病原体同时暴露于太空飞行环境时，人类肠道上皮细胞感染鼠伤寒沙门氏菌（Salmonella Typhimurium）后的多组学（转录组学、蛋白质组学）应答情况。据我们所知，本研究是首个采用人类细胞开展的太空环境下体外感染及双RNA测序（dual RNA-seq）分析。整体实验设计：人类结肠上皮细胞于发现号航天飞机（STS-131任务）搭载的中空纤维生物反应器中开展太空培养。同步地面对照实验则于肯尼迪航天中心，采用完全一致的硬件设备在地球环境中进行。在飞行第11天，向部分培养体系注入鼠伤寒沙门氏菌（~1×10^7 菌落形成单位（CFU）），剩余培养体系作为时间匹配的未感染对照。感染6小时后，将所有培养体系用RNAlater II试剂固定，用于后续飞行后分析。