The innate immune response is the first line of defense for all animals to not only detect invading microbes and toxins but also sense and interface with the environment. One such environment that can significantly affect innate immunity is spaceflight. In this study, we explored the impact of microgravity stress on key elements of the NFκB innate immune pathway. The symbiosis between the bobtail squid Euprymna scolopes and its beneficial symbiont Vibrio fischeri was used as a model system under a simulated microgravity environment. The expression of genes associated with the NFκB pathway was monitored over time as the symbiosis progressed. Results revealed that although the onset of the symbiosis was the major driver in the differential expression of NFκB signaling, the stress of simulated low-shear microgravity also caused a dysregulation of expression. Several genes were expressed at earlier time points suggesting that elements of the E. scolopes NFκB pathway are stress-inducible, whereas expression of other pathway components was delayed. The results provide new insights into the role of NFκB signaling in the squid-vibrio symbiosis, and how the stress of microgravity negatively impacts the host immune response. Together, these results provide a foundation to develop mitigation strategies to maintain host-microbe homeostasis during spaceflight.

先天免疫反应是所有动物的第一道防线，不仅可以检测入侵的微生物和毒素，还可以感知环境并与环境相互作用。太空飞行就是一种可以显着影响先天免疫的环境。在本研究中，我们探讨了微重力应激对 NFκB 先天免疫通路关键元件的影响。在模拟微重力环境下，短尾鱿鱼Euprymna scolopes与其有益共生体费氏弧菌之间的共生被用作模型系统。随着共生的进展，随着时间的推移，监测与 NFκB 通路相关的基因的表达。结果显示，虽然共生的开始是 NFκB 信号差异表达的主要驱动因素，但模拟低剪切微重力的压力也会导致表达失调。几个基因在较早的时间点表达，表明E. scolopes NFκB 途径的元件是应激诱导的，而其他途径成分的表达被延迟。这些结果为了解 NFκB 信号在鱿鱼-弧菌共生中的作用以及微重力压力如何对宿主免疫反应产生负面影响提供了新的见解。总之，这些结果为制定缓解策略以维持太空飞行期间宿主微生物稳态奠定了基础。